A

Project Report on
IOT Based Power Management for DC Microgrid using Solar PV
and EV System
Submitted
In partial fulfillment of the requirements for the degree of

Bachelor of Technology in
Electrical Engineering

Submitted by

Name of Student Roll No

Saniya Aadam Shaikh 2008044
Avadhut Rajendra Jagtap 2009010
Sakshi Uttam Gaikwad 2158022
Nihal Dastgir Mulani 2158023
Chaitrali Prataprao Patil 1808009

Under the Guidance of

Prof. C.L.Bhattar

K.E. Society’s
Rajarambapu Institute of Technology, Rajaramnagar
(An Autonomous Institute, Affiliated to Shivaji University, Kolhapur)
Department of Electrical Engineering
2023-2024

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 K.E. Society’s
Rajarambapu Institute of Technology, Rajaramnagar
(An Autonomous Institute, Affiliated to Shivaji University, Kolhapur)
Department of Electrical Engineering

CERTIFICATE

This is to certify that the project entitled, “IOT Based Power Management for DC Micro
Grid using Solar PV and EV System”, has been carried out and is submitted by Miss.
Saniya A Shaikh , Mr. Avadhut R. Jagtap , Mr. Nihal D. Mulani , Miss. Sakshi U.
Gaikwad and Miss. Chaitrali P. Patil in the partial fulfilment for the award of the degree of
Bachelor of Technology in Electrical Engineering, during the year 2023-24 under my
supervision and guidance within the four walls of the institute and the same has not been
submitted elsewhere for the award of any degree.

Prof. C. L Bhatter

Project Guide External Examiner

Dr. V. N. Kalkhambkar

HOD, Electrical

Date:

Place: R.I.T., Sakharale

DECLARATION

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We declare that this report reflects our thoughts about the subject in our own words. We have
sufficiently cited and referenced the original sources, referred or considered in this work. We
have not misrepresented or fabricated or falsified any idea/data/fact/source in this submission.
We understand that any violation of the above will be cause for disciplinary action by the
institute.

Roll No. Name of Students Signature

2008044 Saniya Aadam Shaikh

2009010 Avadhut Rajendra Jagtap

2158022 Sakshi Uttam Gaikwad

2158023 Nihal Dastgir Mulani

1808009 Chaitrali Prataprao Patil

ACKNOWLEDGEMENT

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At the outset, we think ourselves fortunate enough to have the pleasure of working under the
supervision of Prof. C. L. Bhatter, Assistant Professor, Department of Electrical Engineering.
She stood by our side for this work and her worthwhile guidance, support & reassurance
throughout our project made our work possible. We would like to convey our deep regards and
deep sense of thankfulness to her. We divulge our warm gratitude to faculties and supporting
staff of the department of electrical engineering, and all our close friends and classmates to
cite a few apparitions that helped us to overcome the labyrinth of hardships that come as the
mark of vicissitude. We would like to extent our thanks to the head of electrical engineering
department Dr. V. N. Kalkhambkar for his support throughout this work. We would like to
sincerely acknowledge Director, RIT, Dr. Mr. P. V. Kadole , for her support and
encouragement. Finally, we express our self that working on this subject was throughout the
pleasant learning understanding. We truly hope that this work with its assumption will reflect
the best work put into it. It also has been a wonderful pleasure to relate to the Rajarambapu
Institute of Technology, Islampur.

ABSTRACT

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 The global shift towards greener transportation is a hot topic, and India's efforts in
addressing vehicular emissions are crucial. The high contribution of vehicles to air pollution
underscores the need for a transition to renewable energy-based transportation systems, especially
with the alarming statistics on oil consumption. The analysis is carried out taking into account that the
recharging stations of electric vehicles might be integrated in smart grids, which interconnect the
main grid with distributed power plants, different kinds of renewable energy sources, stationary
electrical storage systems and electric loads. The study is introduced by an analysis of the main
characteristics concerning different kinds of storage systems to be used for stationary and on-board
applications. Then, different charging devices, discharging modes and architectures are presented and
described showing their characteristics and potentialities. It is necessary to monitor battery behaviour
and accordingly utilise it. Range anxiety is the predominant desolation among the electric vehicles
(EV’s) possessors that caused by driver’s ambiguity in relation to vehicle’s energy needed to arrive at
targeted place and state of charge (SoC). This project proposes an intelligent control algorithm for real
time range estimation, indication of various parameters and generates alerts in the smart phone using
Internet of Things (IoT). This algorithm determines the amount of charge present in battery and how
much distance can an electric vehicle move with the remaining power available. Intelligent controller
also improves the battery performance and lifetime. Thereby the integrated system of range estimator
and crash detector will make the electric vehicles smarter. The objective of the project is to promote
green power and to improve the smartness of electric vehicles by integrating the range estimator and
crash detection units alongside to make use of IoT. This makes the generation of alerts when any
abnormalities occur and display the parameters in the virtual dash board.

INDEX
Certificate 2
Declaration 3
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 Acknowledgement 4
Abstract 5
Contents 6
List of Figures 7
List of Tables 8

Chapter Content Page No.

1 Introduction 11
1.1 Introduction 11
1.2 Problem Statement 12
1.3 Objective of project 12
1.4 Scope of project 12
1.5 Closure 12
1.6 Organization of report 13

2 Literature Review 14
2.1 Literature Review 14
2.2 Closure 16

3 Wireless Power Transfer 17

3.1 Wireless Power Transfer 17
3.2 Wireless Power Transmission Methods 18
3.3 Maximum Power Point Tracking 20
3.4 Temperature control using Peltier Module 22
3.5 IoT for graphical data representation 22
3.6 Nodemcu esp8266 24

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4 Block Diagram & Working 28
4.1 Proposed Work (System Block Diagram) 28
4.2 System Working 29
4.3 Components 30

4.4 Hardware Implementation 43

4.5 Closure 44
5 Simulation & Results 45
5.1 Simulation 45
5.2 Results 49
5.3 Closure 49
6 Conclusion and Reference 50
6.1 Future Scope 50
6.2 Conclusion 50

6.3 References 51

Chapter 1
 Introduction

1.1 Introduction
To meet the unprecedented challenges on environmental protection and climate change, electric
vehicles (EVs) and hybrid electric vehicles (HEVs) are developing rapidly in recent years. Compared
with conventional internal combustion engine (ICE) based vehicles, EVs are powered by batteries
that may be charged from renewable power generated from the wind, solar or other forms of
renewable sources. Among all batteries types, Lead acid batteries are preferable power supplies for
EVs due to a number of favourable characteristics such as power density, less pollution, and long
service life. For Lead acid batteries, a proper battery charging strategy is essential in ensuring
efficient and safe operations. The charging strategy is a key issue in the battery management system
(BMS) of EVs. An optimal charging operation will protect batteries from damage, prolong the
service life as well as improve the performance. On the one hand, long charging time will inevitably
affect the convenience of EV usage and limit its acceptance by customers . However, too fast
charging will lead to significant energy loss and battery performance degradation. It is therefore
rational to consider the charging time as one of the key factors in designing the EVs charging control.
Secondly, large energy loss implies low efficiency of energy conversion in battery charging, which
needs to be addressed. Finally, both the battery surface and internal temperatures may exceed
permissible level when it is charged with high current, and the overheating temperatures may
intensify battery aging process and even cause explosion or fire in severe situations. Thus, the battery
charging time, energy loss, and temperature rises are important factors to be considered in designing
the battery charging process.
Electric vehicles becoming the influential means in the field of transport day by day. As these electric
vehicles are free from pollution emission the world is looking to make transportation field electrified.
World need renewable source-based energy supply. The major encumbrance for possessors of electric
vehicles is Range Anxiety, the fear that arises to electric vehicles driver whether he might reach the
destination makes the buyers back step to buy electric vehicles. Various methods and strategies are
implemented to determine range of an electric vehicle. A lot of sensory data is to be collected and could
be applied to estimate range. Multiple variables have to be considered to provide a more accurate
prediction of consumed power. There is a lack of system communication in between driver of electric
vehicle and vehicle battery tracking system. According to the buyer of EV, the main problem with EVs is
the limited capacity of battery and charging infrastructure availability, which leads to a variety of
concerns like drivers are afraid to drive an electric vehicle for far distances. These issues have importance
comparatively cost of batteries and vehicles. Even with development of new battery batteries for electric
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vehicles, various concerns can limit the use of electric vehicles. In recent days, great efforts have been
made to study range reduction concerns by improvising SOC / range evaluation techniques in automotive
battery tracking systems with low-cost microcontrollers. This project presents an easy way to represent
the range in the vehicle’s virtual dashboard. This paper proposes a solution that makes the electric
vehicles smarter by display the parameter like range, speed, battery cycle, location in the mobile
phone. This requires a lot of sensory data to be acquired and send to the cloud. This sensory data is
analyzed at different levels. This project is to promote green power and to improve the smartness of
electric vehicles by integrating the range. This makes the generation of alerts when any abnormalities
occur and display the parameters in the virtual dash board.

1.2 Problem Statement

 Effective power management and coordination in PV system and EV.
 To handle uncertainties for reliable operation.
 Effective charging and discharging control of battery.

1.3 Objective of project

 To design the Solar PV system for charging the electric vehicle.
 To monitor the charging status of battery by using IOT system.
 To measure power (PV power, battery power, load power) using IOT system.

1.4 Scope of project

The scope of IoT-based solar generation for electric vehicles (EVs) is vast and encompasses
several key areas. Firstly, it involves optimizing energy efficiency through the implementation
of intelligent algorithms that can balance solar power generation with the charging needs of
EVs. Real-time monitoring plays a crucial role, providing users with up-to-the-minute data on
solar energy production, consumption patterns, and charging status through IoT-enabled
devices. Integration with the power grid is another essential aspect, enabling bidirectional flow
of energy to and from the grid as needed. Predictive maintenance is facilitated by IoT sensors,
ensuring the health and performance of solar panels and charging infrastructure. The
development of smart charging stations is crucial, allowing for intelligent decisions based on
factors such as weather conditions and grid demand. Furthermore, data analytics plays a pivotal
role in gaining insights into user behavior, energy usage patterns, and system performance,
contributing to continuous improvements in efficiency. User engagement is enhanced through
user-friendly interfaces and applications that provide information on energy consumption and
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 environmental impact. Interoperability is also a key consideration, ensuring seamless
integration across various EV models and standardizing communication protocols. In summary,
IoT-based solar generation for EVs holds immense potential in advancing sustainable and
efficient energy practices.

1.5 Closure

This chapter gives a brief idea about the introduction to the project. It also contains the
problem statement along with their scope. The objectives are also stated for the development
of the overall project.

1.6 Organization of Report

Chapter 1 talks about the brief information about the project. This includes introduction
importance of the problem, problem statement, objective, and scope of the project.

Chapter 2 represents literature survey from different research papers also gives overview of
different machines and different experiments done for simulating the project.

Chapter 3 represents different methods of wireless power transmission. It also contains PV

panel, maximum power point tracking concept with P&O algorithm, temperature control
using peltier module, IoT for graphical data representation, IoT interface platform.

Chapter 4 represents proposed block diagram along with its working and the components
used.

Chapter 5 represents simulation and results of the project.

Chapter 6 represents Future Scope, Conclusion and references.

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 Chapter 2
Literature Review

2.1 Literature Review

Nowadays, EVs represent an interesting solution for the growing dependence from fossil fuels,
since they allow a considerable reduction of air pollution. However, the diffusion of EVs is still
affected by many issues, which are mainly due to interaction and integration of these types of
vehicles with the existing power grid. Moreover, in order to have a wide diffusion on the market of
no polluting vehicles, they have to present the characteristics of travel ranges and recharging times
comparable to the traditional oil-based fuel vehicles. For these reasons EVs require battery packs
characterized by high values of both energy storage capacity and charging rates. From this point of
view lead acid based batteries represent a very interesting solution, as they are showing a great
potential, in recent years, to supply electric vehicles having good performance in terms of
acceleration and driving range. Nowadays, new technologies of lead acid compounds are available,
which permit reaching an specific energy up to 180 Wh/kg and a maximum charging rate of 6 C
reducing the charging times up to 10 minutes [1]. Typical charging modes at low power are suitable
for the refilling of battery packs during the night in 7÷8 hours, ensuring low power requirements for
the grid. In fact, recent studies demonstrate that the daily travel range is less than 50 km in 80% of
the cases. For this reason such slow recharging would be acceptable for most users ensuring a travel
range from 100 to 150 km during the daylight [2]. Longer traveling distances would require frequent
electric service stations along the way, able to satisfy the requirements of a significant amount of
power, supplied to the battery packs, on order to obtain filling times similar to oil-based fuel cars. In
this case, the battery pack could be charged in a few minutes, although a power range from 20 kW (in
case of small city EVs) to 250 kW (in case of heavy vehicles) would be required [3]. The existing
electric infrastructures may not be specifically designed to satisfy this great increase in power
demand. For this reason, a large deployment of EVs involve the evaluation of the impacts that the
charging of vehicles may have on the national power-grid and identification of the best charging
strategies to be adopted. These strategies should take into account the number of vehicles to be
recharged, both during the night and daylight, the proper integration with RESs and the characteristic
of EVs to feed electric energy back to the grid, becoming in this case an active load (V2G concept)
and providing several ancillary services, such as peak power and back up [4]. Moreover, the
evaluation of charging strategies needs to take in to account the electric energy price and the habits of
the EVs owners. On this regard the EV aggregation agent (also called aggregator as abbreviated
term) plays an important role in between the EV owners and electricity market, DSO &

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 transmission system operator, mainly based on the control of the EV charging/discharging rates. This
role of an EV aggregation agent is justified by the fact that each EV owner is unable to manage energy
transactions between their vehicle and electric power grid, essentially because of their low electric
power capacity (generally few kW). Furthermore, an aggregation agent technically makes simpler a
smart charging of vehicles [5].

i. Gayathri M. S., Ravishankar A. N., Kumaravel S., and Ashok S. Battery Condition
Prognostic System using IoT in Smart Microgrids.
This paper presents an idea to share the battery condition monitoring parameters among the
stakeholders like manufacturer, market dealers, users etc. by using latest Internet of Things (IoT)
technology.

Ii. Miftahul Anwar1, Muhammad D. Ashidqi1, Sunarto Kaleg, Feri Adriyanto1, Sukmaji.
Cahyono, Abdul Hapid, Kuncoro Diharjo, State of Charge Monitoring System of Electric Vehicle
Using Fuzzy Logic.
The purpose of this research was to design a state of charge (SoC) monitoring device and to understand
the effect of temperature on SoC during trials of an electric golf cart.

iii. Iii. Mohammad Asaad1, Furkan Ahmad1, Mohammad Saad Alam1, Yasser Rafat2, IoT
enabled Electric Vehicle’s Battery Monitoring System.
This paper proposes a real-time Battery Monitoring System (BMS) using coulomb counting method for
SoC estimation and messaging based MQTT as the communication protocol. The proposed BMS is
implemented on hardware platform using appropriate sensing technology, central processor, interfacing
devices and the Node-RED environment.

iv. Iv. YANG Xu, SHEN Jiang, TONG XIN Zhang, Research and design of lead acid battery
management system for electric bicycle based on Internet of things technology.
This paper designs an electric bicycle battery management system based on Internet of, things
technology. With appropriate software and hardware design, effective monitoring of battery pack status
information can be achieved, and effective real-time transmission of battery status and location
information to the monitoring platform, to meet the requirements of battery operation management units
for real time monitoring of batteries.

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v. Kasa Sudheer, K Hemanth Kumar, N Puneethkumar, K VishnuVardhan Reddy. IoT Based
Intelligent Smart Controller for Electric Vehicles.
This paper proposes an intelligent control algorithm for real time range estimation, indication of
various parameters and generates alerts in the smart phone using Internet of Things (IoT). This
algorithm determines the amount of charge present in battery and how much distance can an electric
vehicle move with the remaining power available.

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 Chapter 3
Block Diagram & Working
3.1 Block Diagram-

Above figure shows the block diagram of IOT based Power Management for DC Micro Grid using
solar PV and EV system. Renewable energy is used to generate electricity i.e. Solar panels are used to
generate electricity this power is used to satisfy the residential load and EV battery. Generated power
then transferred to load by using DC-DC converter. DC – DC converter is connected with MPPT
which provides maximum power point signals to the converter.
When generation is more than the load then excess power is transferred to battery and when
generation is less than load then battery will supply the load.

SOC -
Battery Pack

SOC via Open Circuit

terminal voltage method

Coulomb counting

- 14of -battery is
charge rate
processed

Charge remaining is estimated

 Fig.1 Proposed Control Scheme

Fig.1 clearly describes the working process of controller. In current system, coulomb counting
method is used, due to its low complexity and simplicity. Primarily, coulomb counting calculation
technique is based on integrated current and amount of charge that has to be delivered by sensing
input and output of the battery. It operates by introducing an active flow over time to obtain the total
amount of energy that goes into or out of the battery. As a result, measured in ampere hours.
Obviously, if the current measurement is accurate, the method is reliable. It applies to all batteries
used in the EV application.

1. Begin coulomb counter in Arduino

2. Set voltage value to zero

3. Establishing communication in between the Arduino and system.

4. Insert load and operate with battery

5. Coulomb counter transmits the results to Arduino.

6. Transform and save results to digital from analog format.

7. Display the outputs.

8. Notify the user when the battery reaches a safe SOC.

9. If the battery is plugged in for charging, the Coulomb counter stops until it
is charged, or if it is not plugged in, the battery sends regular alerts to stop
the charging and to stop the connection.

10. Post battery charging, coulomb counter transforms its state to running state
from idle.

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 Fig.2 Block diagram of " Internet of things Based Battery Monitoring System”

Here, the Arduino (Atmega328) is the main part of our project. Arduino code is analyzed in Proteus
8 profession software. Logic mainly includes 4 modules. Such as battery cooling system, range
estimation, alerting mechanism, auxiliary load control. In battery cooling system, temperature
sensor continuously monitors the battery temperature and activates the cooling fan automatically
when threshold is reached. Control logic considers energy available with battery, past state of
vehicle, current state of vehicle whether it is in standstill or running condition. Based on all the
received data algorithm estimates the available distance that vehicle can go further.

Alerting mechanism generates timely alert messages at local as well as remotely based on the signals
received from all the sensors. This Intelligent controller has intelligent mode, under which vehicle is
run with optimal energy consumption by controlling the auxiliary

State-of-Charge Estimation
The state of charge is estimated by reading the battery voltage v and comparing it to a series of
values stored in a lookup table l0-l8. The threshold voltages are derived from the particular discharge
curve shown below for the LG 18650 HE4 cells used in this
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The remaining capacity and charge duration are derived as follows:
Mah=cfull*(100-soc)*1.3
Tmax= 3600.cfull/icharge(90-soc)+45*60
Where cfull/cmax is the battery design capacity and icharge is the nominal charging current. Note
that cmax is increased by 30% and tmax is increased by 45 minutes in order to to account for
resistive losses and soc estimation inaccuracy.
Safety
The charger implements several safety features. These include undervoltage, overvoltage, short
circuit and open circuit detection.
The typical voltage range where a Lead acid battery can safely operate is between vmin=2.5v/cell and
vmax=4.2v/cell. Operating outside this range is likely to cause permanent damage to the Lead acid
cells and may even result in a catastrophic failure such as an explosion or fire.
The battery pack is additionally protected by a battery protection board (or Battery Management
System aka BMS). The BMS measures the voltages of the individual battery cells as well as the
charge/discharge current flowing through the battery. The BMS uses a solid-state switch to
disconnect the battery as soon as the voltage or current values become outside of the specified limits.
For the most part, the BMS is completely transparent and does not interfere with the charging
process, except for the case where the BMS disconnects the depleted battery in order to prevent
overdischarge. In this case, the voltage of the depleted battery is still present across the BMS
terminals through a high value resistor placed in series with the battery. This high value resistor
causes a much lower voltage value to be measured at the charger terminals. Consequently, the charger
must ignore the vmin lower limit and start charging at a much lower value of as low as
vstart=0.5v/cell. When presented with a depleted battery, the charger would start charging at a
reduced safety current isafe=icharge/10 until the battery voltage reaches vsafe=2.8v/cell, afterwards it
would apply the full charging current . Once the voltage reaches this threshold, it is no longer
allowed to drop below the vmin. A voltage below vmin would raise an “undervolt error” which is
may caused by either a short circuit or a battery open circuit.
Voltage Calibration-
Having performed the above initial step, please proceed for calibrating the ADC readings for the
voltages v1, v2 as shown below:
1. Enter the command cal start into the serial monitor, this will activate the calibration mode. The
message Calibration start should appear on the serial monitor.
2. Connect a constant voltage source of approximately 750mV between the B-terminal and the power
supply ground (OV) and measure its exact value using a digital multimeter. Note that 750mV
corresponds to 1.5A flowing through the shunt resistors R8 and R9.

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3. Enter the command cal v2 <value> into the serial monitor, where <value> is the value in mV of the
voltage measured in the previous step (e.g. 754). The value of the calibration constant v1,cal will be
displayed upon the successful calibration of v2. If the calibration fails, the message Out of range will
appear in the serial monitor.
4. Connect a constant voltage source of approximately 16800mV (4200mV per cell) between. the B+
terminal and the power supply ground (OV) and measure its exact voltage using a digital multimeter.
5. Enter the command cal v1 <value> into the serial monitor, where <value> is the value in mV of the
voltage measured in the previous step (e.g. 16450). The value of the calibration constant v1,cal will
be displayed upon the successful calibration of v1. If the calibration fails, the message Out of
rangewill appear in the serial monitor.
6. Verify the voltage calibration by applying a known voltage to each of B+ and B- (relative to OV),
then enter the (dot) command and check the displayed values for v1 and v2 which must match the
measured voltages at B+ and B-as closely as possible.
7. Repeat steps 2, 3, 4, 5 and 6 until the voltage readings are correct.
8. Enter the command cal stop in order to exit the voltage calibration mode. The message Calibration
stop should appear on the serial monitor.

Current Calibration-
Please proceed with calibrating the reading of the current by following the steps below:

1. Connect a discharged Lithium-lon battery to in series with a digital amperemeter (set to the 10A
range) to the terminals B+ and B-

2. The message Charging should appear in the serial monitor and the measured current value should
start to gradually increase until it reaches a maximum of approximately 1.5A.

3. Enter the (dot) command and check the displayed value for which must match the measured
current as closely as possible..

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4. If the output of the command is higher than the amperemeter reading increase the value of rshunt by
10m2 by calling the r shunt command.

5. If the output of the command is lower than the amperemeter reading decrease the value of rshunt by
10m2 by calling the rshunt command.

6. Repeat steps 3, 4 and 5 until you get an accurate reading of current.

Lead acid (Lead acid) batteries’ advantages have cemented their position as the primary power source
for portable electronics, despite the one downside where designers have to limit the charging rate to
avoid damaging the cell and creating a hazard. Fortunately, today’s Lead acid batteries are more robust
and can be charged far more rapidly using “fast charging” techniques.
This article takes a closer look at Lead acid battery developments, the electrochemistry’s optimum
charging cycle, and some fast-charging circuitry. The article will also explain the downsides of
accelerating charging, allowing engineers to make an informed choice about their next charger
design.
The concept behind lead acid-ion (Lead acid) batteries is simple but it still took four decades of effort
and a lot of research dollars to develop the technology that now reliably powers the majority of
today’s portable products.
The earliest cells were fragile and prone to overheating during charging, but development has seen
those drawbacks overcome. Nonetheless, recharging still needs to follow a precise regimen that
limits charge currents to ensure full capacity is reached without overcharging with its associated risk
of permanent damage. The good news is that recent developments in materials science and
electrochemistry have increased the mobility of the cell’s ions. The greater mobility permits higher
charge currents and speeds up the “constant current” part of the charging cycle.
These developments enable smartphones equipped with the latest generation of Lead acid batteries to
be charged from around 20% to 70% capacity in 20 to 30 minutes. A brief battery refresh to
threequarter-capacity appeals to time-poor consumers, opening up a market sector for chargers that
can safely support quick charging. Chip vendors have responded by offering designers ICs that
facilitate various charging rates to accelerate battery replenishment for Lead acid cells. Faster
charging is the result, but as always, there is a trade-off to be made.

Portable power enhancements

Lead acid cells are based on intercalation compounds. The compounds are materials with a layered
crystalline structure that allow lead acids to migrate from, or reside between, the layers. During
discharge of a Lead acid battery, ions move from the negative electrode through an electrolyte to the
positive electrode, causing electrons to move in the opposite direction around the circuit to power the
load. Once the ions in the negative electrode are used up, current stops flowing. Charging the battery
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forces the ions to move back across the electrolyte and embed themselves in the negative electrode
ready for the next discharge cycle
While these materials are satisfactory, things are not perfect. Each time the ions are shifted, some
react with the electrode, become an intrinsic part of the material, and so are lost to the
electrochemical reaction. As a result, the supply of free ions is gradually depleted and battery life
diminishes. Worse yet, each charging cycle causes volumetric expansion of the electrodes. This
stresses the crystalline structure and causes microscopic damage that diminishes the ability of the
electrodes to accommodate free ions. This puts a limit on the number of recharge cycles.
Addressing these weaknesses has been the focus of recent Lead acid battery research, with a primary
goal of packing more lead acids into the electrodes to increase the energy density, defined as energy
per unit volume or weight. This makes it easier for the ions to move in and out of the electrodes, and
eases the passage of the ions through the electrolyte (i.e. enhancing ion mobility).
Charging time (for a given current) is ultimately determined by the battery’s capacity. For example, a
3300 mAhr smartphone battery will take approximately twice as long to charge as a 1600 mAhr
battery, when both are charged using a current of 500 mA. To take account of this, engineers define
charging rates in terms of “C”, where 1 C equals the maximum current the battery can supply for one
hour. For example, in the case of a 2000 mAhr battery, C = 2 A. The same methodology applies to
charging. Applying a charge current of 1 A to a 2000 mAhr battery equates to a rate of 0.5 C. It
would seem to follow, then, that increasing the charging current will decrease the recharge time. This
is true, but only to a certain degree. Firstly, ions have a finite mobility, so increasing the charging
current past a certain threshold doesn’t shift them any quicker. Instead, the energy is actually
dissipated as heat, raising the battery’s internal temperature and risking permanent damage.
Secondly, unrestricted charging at a high current eventually causes so many ions to embed into the
negative electrode that the electrode disintegrates and the battery is ruined.
Recent developments have significantly improved the ion mobility of the latest Lead acid cells,
allowing the use of a higher charging current without dangerously raising the internal temperature.
But even in the most modern products there is still a risk in overcharging because it is a direct result
of the physical make-up of the cell. Consequently, Lead acid battery makers prescribe a strict
charging regimen to protect their products from damage.
Carefully does it
Lead acid battery charging follows a profile designed to ensure safety and long life without
compromising performance (Figure 2). If a Lead acid battery is deeply discharged (for example, to
below 3 V) a small “pre-conditioning” charge of around 10% of the full-charge current is applied.
This prevents the cell from overheating until such a time that it is able to accept the full current of the
constant-current phase. In reality, this phase is rarely needed because most modern mobile devices
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are designed to shut down while there’s still some charge left because deep discharge, like
overcharging, can damage the cell.
Then, the battery is typically charged at a constant current of 0.5 C or less until the battery voltage
reaches 4.1 or 4.2 V (depending on the exact electrochemistry). When the battery voltage reaches 4.1
or 4.2 V, the charger switches to a “constant voltage” phase to eliminate overcharging. Superior
battery chargers manage the transition from constant current to constant voltage smoothly to ensure
maximum capacity is reached without risking damage to the battery.
Maintaining a constant voltage gradually reduces the current until it reaches around 0.1 C, at which
point charging is terminated. If the charger is left connected to the battery, a periodic ‘top up’ charge
is applied to counteract battery self discharge. The top-up charge is typically initiated when the
opencircuit voltage of the battery drops to less than 3.9 to 4 V, and terminates when the full-charge
voltage of 4.1 to 4.2 V is again attained.
As mentioned, overcharging severely reduces battery life and is potentially dangerous. Once the ions
are no longer moving, most of the electrical energy applied to the battery is converted to thermal
energy. This causes overheating, potentially leading to an explosion due to outgassing of the
electrolyte. As a result, battery makers advocate precise control and suitable charger safety features.
Undercharging, while not dangerous, can also have a detrimental effect on battery capacity. For
example, undercharging by a little as 1% can reduce the battery capacity by around 8%
For these reasons, the charger should control the final voltage to within ±50 mV of 4.1 or 4.2 V and
be able to detect when the battery is fully charged. Detection methods include determining when the
current drops to 0.1 C during the constant-voltage stage and, in more basic chargers, charging for
only a predetermined time and assuming the battery is fully charged. Many chargers also include
facilities to determine the battery temperature, so that charging can cease if a threshold is exceeded.
Thermal control:

AVR atmega 328p-pu ic is used as heart of system which will sense temperature via inbuilt
ADC and generate PWM signal to control supply of peltier plate w. r. to temperature and
charge the battery.

Proposed design uses peltier plate to control the thermal heat of lead acid battery.
First temperature is measured by temperature sensor and given to microcontroller unit that will
convert to digital form from analog one. Also microcontroller will compare the battery temperature
and generates the actuator signal in pwm form to control the peltier plate voltage/current so as to
cool the battery. Design compiles a very compact size which can be fitted in any vehicle easily with
low cost design.

- 21 -
LCD Interfacing with the Arduino Module

The following circuit diagram shows the liquid crystal display with the Arduino module. From the
circuit diagram, we can observe that the RS pin of the LCD is connected to the pin 12 of the Arduino.
The LCD of R/W pin is connected to the ground. The pin 11 of the Arduino is connected to the
enable signal pin of LCD module. The LCD module & Arduino module are interfaced with the 4-bit
mode in this project. Hence there are four input lines which are DB4 to DB7 of the LCD. This
process very simple, it requires fewer connection cables and also we can utilize the most potential of
the LCD module.
The digital input lines (DB4-DB7) are interfaced with the Arduino pins from 5-2. To adjust the
contrast of the display here we are using a 10K potentiometer. The current through the back LED
light is from the 560-ohm resistor. The external power jack is provided by the board to the Arduino.
Using the PC through the USB port the Arduino can power. Some parts of the circuit can require the
+5V power supply it is taken from the 5V source on the Arduino board.

- 22 -
Mosfet interface

Here we will explore the use of photovoltaic output opto-couplers. These are often used to drive
power MOSFETs. These are based on the use of an array of photodiodes connected in series used
to generate a gate drive voltage.

Fig. shows the use of a NPN transistor output opto-coupler to switch the turn-on voltage to the gate
of Q1 a N-channel MOSFET.

The proposes a lead acid-ion battery charging technique for the charge equalization controller based
on the particle swarm optimization (PSO) algorithm. A flyback DC-DC converter is utilized to
perform the charge equalization and battery charging. The charging of lead acid-ion battery is
executed by constant current-constant voltage (CCCV) charge PID control process. In the proposed
technique, the PSO algorithm is used to attain the best and optimal values of the PI controller
parameters. The optimized PID controller regulates the PWM signal to the MOSFET switching
drive of the converter for quality CC-CV charging of the lead acid-ion battery, so that it reduces the
memory effect, and thus, enhances the performance of lead acid-ion battery and equalization. The
proposed charging technique for efficient charge equalization controller is applicable in energy
storage applications toward the sustainable electric vehicle development.

- 23 -
 PV Panel

Above Figure 3.3.1 depicts the parallel-connected current source and diode. Solar cells can be
connected in the parallel or in the series to create a PV array. Solar PV modules work on the
principle of photovoltaic effect, which is the process of converting sunlight into electricity.
When sunlight hits the photovoltaic cells, it releases electrons, which flow through the circuit
and generate a current. This current is then used to power electrical devices and charge
batteries
(1)

(2)

Maximum Power Point Tracking (MPPT)

Utilizing concentrated power under any environmental conditions is how MPPT is applied. The MPPT
method undoubtedly increases the efficiency of a PV panel. Here, the MPPT technique is being used for
both observation and perturbation.

- 24 -
- 25 -
 The Buck converter was chosen for this project due to its simpler concept than the rest. In
general, buck converters in steady state should have the following properties: inductor current
should be periodic and continuous, the average inductor voltage should be zero, the average
capacitor current should be zero, and most importantly, the power delivered to the load should be the
same as power supplied by the source for ideal components. For non-ideal components, the power
losses should be taken into the account as well [15].
One of the key factors of this project was the CC CV algorithm and the way this algorithm
implemented on our system. As it was mentioned before, PWM method is chosen to maintain the CC
CV. This method was based on the electrical power that was calculated with voltage and current
from DC/DC converter and then, it compared the power at each moment and tracked the maximum
power by modifying the duty cycle via pwm of the system. To implement this algorithm, Matlab
software was used to simulate the whole system and test out the code before implementing it
practically. Matlab software was chosen due to its ability to simulate and code in one file. Using the
flowchart of the algorithm, the code was written step by step [25].

simulation
model of the DC-DC converter. The input capacitor is compulsory to steady the input voltage due to
the peak current must of exchanging power supply. Specification of inductor is very important which
decided through the following equation.

The instantaneous power delivered by the solar panel at each moment was calculated by
measuring the output voltage and current across the DC/DC converter and multiplying both
quantities. This function executed in a loop so that it would be repeated and produced multiple
power readings: P1, P2, … Pn, Pn+1. If the new power, Pn+1 is higher than the previous value Pn,
then the operating voltage is compared. If the new voltage Vn+1 is greater than the previous
voltage Vn, then the duty cycle decreased, else the duty cycle increased. Otherwise, if the new
power is less than the previous value and the new voltage is greater than the previous voltage, then
the duty cycle increased, else the duty cycle decreased. Modifying the duty cycle would change the
operating voltage and the power would be calculated again, which would always result in
maximum power point.

- 26 -
ESP8266 is the name of an infamous WiFi module that is a system on a chip (SoC) developed by
Espressif Systems, a company based in Shanghai. Originally used with Arduino boards to
WiFienable hardware projects, it soon became a cheap standalone Arduino-compatible development
board. It can function in complete autonomy, without an additional microcontroller like Arduino
board for example.

Home automation and IOT – connecting devices to a network is one ever-growing, big trend
nowadays. Given its cheap price, the user friendly setup, and its huge community that contributes
with open source libraries and projects, you will immediately see why this chip is receiving so much
interest.

This mcu (microcontroller unit) can be used to control and monitor engineered systems and products,
sensor data logging and more. All of this makes it the perfect piece of hardware for connected home
automation projects. It comes in many shapes and forms, with the NodeMcu (with the newest
ESP8266-E12 chip) being the most popualar development board among them.

ESP8266: Specifications
All ESP8266 variants have a ESP8266EX core processor and a Tensilica L106 32-bit micro
controller unit. This is a low cost, high performance, low power consumption, easy to program,
wireless SoC(System-On-Chip). It provides capabilities for 2.4 GHz Wi-Fi (802.11 b/g/n, supporting
WPA/WPA2), general-purpose input/output (13 GPIO), Inter-Integrated Circuit (I²C), analog-
todigital conversion (10-bit ADC), Serial Peripheral Interface (SPI), I²S interfaces with DMA
(sharing pins with GPIO), UART (on dedicated pins, plus a transmit-only UART can be enabled on
GPIO2), and pulse-width modulation (PWM).

- 27 -
It has a build-in programmer and a voltage regulator, that allow flashing and powering the device via
micro-USB. The system operates at 3.3V.

Here is an overview of the ESP8266 NodeMcu’s specifications:

• Tensilica L106 32-bit micro controller unit at 80 MHz (or overclocked to 160 MHz)
• 32 kB instruction RAM
• 80 kB user data RAM
• 16 kB ETS system data RAM
• Flash Memory 4Mb
• USB – micro USB port for power, programming and debugging
• 13 GPIO pins
• 802.11 b/g/n, supporting WPA/WPA2
• STA / AP modes support
• TCP / IP protocol stack, One socket
• TCP / UDP Server and Client
• Pin-compatible with Arduino UNO, Mega
• KEY button: modes configuration
• 32-bit hardware timer
• WiFi operation current: continuous transmission operation: ≈70mA (200mA MAX), deep
sleep mode: <3mA
• Serial WiFi transmission rate: 110-460800bps
• Temperature: -40℃ ~ + 125 ℃
• Humidity: 10%-90% non-condensing
• Weight: about 20g (0.7oz)
• Pulse-Width Modulation (PWM)
• Interrupt capability
• 3.3V operating voltage, internal voltage regulator allows 5V on power input
• maximum current through GPIO pins: 12mA (source), 20mA (drain)
• available firmware for Arduino IDE
• Websocket libraries available

Transfer Control Protocol (TCP):

Most of us would know what this means. Yes, these are the set of rules based on which the internet
works. Since ESP8266 has the ability to set up WIFI connections. At a high level Wi-Fi is the ability
to participate in the TCP/IP connections over a wireless link. You can make your ESP to work on the
TCP/IP protocol or the UDP protocol.
- 28 -
User Datagram Protocol (UDP):

UDP is also another type of internet protocol. This type of communication is faster than TCP but it is
less accurate. The reason is that TCP uses an Acknowledgment during its communication but UDP
does not. TCP is mostly used in networks where there is a requirement high reliability. UDP is used
in places where speed has high priority than reliability. For example UDP is used in video
conferencing, because there even if some pixels are not transmitted it will not affect the video quality
Most of the ESP8266 projects and codes work around the TCP/IP, UDP will be least bothered.

Web socket:

According to Wikipedia, a Websocket is a computer communications protocol, providing full-duplex

communication channels over a single TCP connection. The WebSocket protocol was standardized
by the IETF as RFC 6455 in 2011, and the WebSocket API in Web IDL is being standardized by the
W3C.
In other words, Websocket is a protocol based on TCP that enables realtime communication between
server and host, while the communication is kept alive after an initial handshake. It has a small
overhead and little data is sent to keep the connection alive. It is used in chat applications, sensor
data stream reading or real-time data exchange, for example. Access Point (AP) and Station
(STA):

Once you start working with ESP module, you would come across these two terms frequently. Let us
say you and your friend would like to surf the internet on your smart phones but since he does not
have an active internet connection you decide to turn on your hotspot and your friend connects to it.
Here your phone which is sourcing the internet connection is the Access Point (AP) and your friend’s
phone which is using the internet is called the Station (STA).

ESP8266 module can be used in three modes, AP mode, STA mode or in both STA and AP mode
(combined).

IoT interface platform

ThingSpeak is IoT Cloud platform where you can send sensor data to the cloud. You can also analyze
and visualize your data with MATLAB or other software, including making your own applications.

The ThingSpeak service is operated by MathWorks. In order to sign up for ThingSpeak, you must
create a new MathWorks Account or log in to your existing MathWorks Account.

ThingSpeak is free for small non-commercial projects.

- 29 -
ThingSpeak includes a Web Service (REST API) that lets you collect and store sensor data in the
cloud and develop Internet of Things applications. It works with Arduino, Raspberry Pi and
MATLAB (premade libraries and APIs exists) But it should work with all kind of Programming
Languages, since it uses a REST API and HTTP.

A network of "connected things" is known as the Internet of Things (IoT). The majority of
the time, the items have an embedded operating system and a communication interface for
the internet or other nearby things. An IoT service is one of the essential components of a
general IoT system that connects the numerous 'things'. The 'items' that make up the IoT
systems have an interesting implication: they are powerless to act on their own. They ought
to be able to connect to other 'things' at the very least. However, when the objects link to a
"service," either directly or through other "things," the true power of IoT can be realised. By
offering capabilities ranging from straightforward data gathering and monitoring to intricate
data analyses, the service assumes the position of an invisible manager in such systems.
ThingSpeak is a platform with a wide range of services created for creating Internet of
things(IoT) applications. It allows for the real-time data collection, charting, and
development of plugins and apps for engaging with web services, social media, and other
APIs. IoT for Graphical Data Representation
CODE
#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
#include <SoftwareSerial.h>
//String agAdi = "IQOO 9 SE";
//String agSifresi = "project";

- 30 -
String agAdi = "project";
String agSifresi = "123456789";
int rxPin = 12;
int txPin = 13;
#include "dht.h"
const int mot1=9;
const int mot2=10;
const int mot3=11;
//String ip = "184.106.153.149"; //please dont change ip
String ip = "api.thingspeak.com";
SoftwareSerial esp(rxPin, txPin);

dht DHT ; // declaring dht a variable

#define DHT11_PIN A4 // initializing pin 8 for dht
//int relay = 13;
double Voltage =
0; double Current
= 0; //const int
voltsIn = A3; float
volts; const int pv
= A3; float pvolts;
float
temperature1=0.0;
int sensitivity =
100; int adcValue=
0; int offsetVoltage
= 2500; double
adcVoltage = 0;
double
currentValue = 0;
float E=0.0;

const int in1=A1;

const int in2=A2;
int count=0;

- 31 -
void setup()
{
Serial.begin(9600);
lcd.begin(16, 2);
pinMode(mot1,OUTPUT);
pinMode(mot2,OUTPUT);
pinMode(mot3,OUTPUT);
pinMode(in1,INPUT_PULLUP);
pinMode(in2,INPUT_PULLUP);
lcd.setCursor(0,0);
lcd.print("IOT BASED EV BAT");
lcd.setCursor(0,1);
lcd.print("MANAGEMENT SYSTM");
esp.begin(115200);
esp.println("AT");
Serial.println("AT send "); while (!
esp.find("OK")) {
esp.println("AT");
Serial.println("ESP8266 Not find.");
}
Serial.println("ok command
received");
esp.println("AT+CWMODE=1");
while (!esp.find("OK")) {
esp.println("AT+CWMODE=1");
Serial.println("setting ...");
}
Serial.println("Set as client");
Serial.println("connecting to network");
esp.println("AT+CWJAP=\"" + agAdi + "\",\"" + agSifresi + "\"");
while (!esp.find("OK"));
Serial.println("Connected to the
Network."); delay(1000); lcd.clear();
lcd.print("n/w connected"); delay(5000);
lcd.clear();
}

- 32 -
void loop(){ esp.println("AT+CIPSTART=\"TCP\",\"" +
ip + "\",80");
if (esp.find("Error")) {
Serial.println("AT+CIPSTART Error");
}
measure();

String veri = "GET https://api.thingspeak.com/update?api_key=4TN8KZITZAUYU50U";

veri += "&field3=";
veri +=
String(temperature1);
veri += "&field1="; veri +=
String(pvolts); veri +=
"&field2="; veri +=
String(Current); veri +=
"&field4="; veri +=
String(E); veri += "\r\n\r\n";
esp.print("AT+CIPSEND=");
esp.println(veri.length() + 2);
delay(2000);
if (esp.find(">"))
{ esp.print(veri);
Serial.println(veri);
Serial.println("data send.");
delay(20000); lcd.clear();
lcd.print("sent-2thingspeak");
delay(1500); lcd.clear();
}
// Serial.println("Connection Closed.");
//esp.println("AT+CIPCLOSE");
delay(1000);

- 33 -
void measure(){ float pvoltSum = 0.0; for (int
i = 0; i < 10; i++){ pvolts =
map(analogRead(A3), 0, 1023, 0, 320);
pvoltSum = pvoltSum + pvolts; delay(200);
}
pvolts =pvoltSum /100.0;

lcd.setCursor(8,0);
lcd.print("V=");
lcd.print(pvolts);
lcd.print("V");

for(int i = 0; i < 1000; i++) {

Voltage = (Voltage + (.0049 * analogRead(A5))); // (5 V / 1024 (Analog) = 0.0049) which
converter Measured analog input voltage to 5 V Range delay(1);
}
Voltage = Voltage /1000;
Current = (Voltage-2.5)/ 0.185; // Sensed voltage is converter to current

lcd.setCursor(0,0);
lcd.print("I=");
lcd.setCursor(2,0);
Current=Current+0.0;
lcd.print(Current,2);
lcd.setCursor(0,1);
lcd.print("E=");
E=((Current*pvolts)/14);
lcd.print(E);

int chk = DHT.read11(DHT11_PIN ) ; // Checking that either the dht is working or not

lcd.setCursor(9,1);

lcd.print ("T=") ; // printing the “ Temperature is : ― on the lcd

- 34 -
 lcd.print ( DHT.temperature ) ; // printing the temperature on the lcd

temperature1=( DHT.temperature );

delay(5000); if(pvolts<13)
{ analogWrite(mot1,200);
}

if(pvolts>14)
{ analogWrite(mot1,0);
}

if(pvolts>11)
{ analogWrite(mot2,150);
analogWrite(mot3,150);

} if(pvolts<10.8)
{ analogWrite(mot2,
0);
analogWrite(mot3,0);
}

- 35 -
GENERAL COMPONENTS
RESISTORS :

In many electronic circuit applications the resistance forms the basic part of the circuit.
The reason for inserting the resistance is to reduce current or to produce the desired
voltage drop. These components which offer value of resistance are known as resistors .
Resistors may have fixed value i.e., whose value cannot be changed and are known as
fixed resistors. Such of those resistors whose value can be changed or varied are known
as variable resistors.

There are two types of resistors available. They are :

 Carbon resistors .
 Wire wound resistors .

Carbon resistors are used when the power dissipation is less than 2W because they are
smaller and cost less. Wire wound resistors are used where the power dissipation is more
than 5W . In electronic equipments carbon resistors are widely used because of their
smaller size .

All resistors have three main characteristics:

 Its resistance R in ohms (from 1 ohm to many mega ohms).

 Power rating (from several 0.1W to 10 W).
 Tolerance (in percentage).

RESISTOR COLOR CODING:

- 36 -
The carbon resistors are small in size and are color coded to indicate their resistance value in
ohms. Different colors are used to indicate the numeric values. The dark colors represent lower
values and the lighter colors represent the higher values. The color code has been standardized
by the electronic industries association.

The color bands are printed at one end of the resistors and are read from the left to right. The
first color band closed to the edge indicates the first digit in the value of resistance .The second
band gives the second digit. The third band gives the number of zero’s after two digits . The
resulting number is the resistance in ohms . A fourth band indicates the tolerance i.e., to
indicate how accurate the resistance value is , the bands are shown in the figure 1.

Fig. 1: Colour code for Resistor

PRESET:

There are two general categories of variable resistors:

 General purpose resistors.
 Precision resistors.

- 37 -
 The general purpose type can again be wire wound type and carbon type .These follows
either linear or logarithmic law. The precision type are always wire wound and follow a
linear law .The variable resistors can be broadly classified as potentiometer , rheostats ,
presets and decade resistance boxes.

The general purpose wire wound potentiometers are available in 1, 2, 3 and 4 watts. The
usual tolerances ratings 10 % and 20% are available. The widely used potentiometers are
of the standard diameters 19mm, 31mm, and 44mm. The temperature coefficient
depends on the wire used and on the resistors values. The resolution of these wire wound
resistors is proper than carbon resistors because the wiper has to move from one winding
to the other, where as in carbon potentiometers it is continuous. These resistors are
highly linear, the linearity falling with 1%.

CAPACITORS:

Devices which can store electronic charge are called capacitors. Capacitance can be
understood as the ability of a dielectric to store electric charges. Its unit is Farad, named
after the Michael Faraday. The capacitors are named according to the dielectric used.
Most common ones are air, paper, and mica, ceramic and electrolytic capacitors.

Physically a capacitor has conducting plates separated by an insulator or the dielectric.

The plates of the capacitor have opposite charge, this gives rise to an electric field .In
capacitor the electric field is concentrated in the dielectric between the plates.

Like resistors, capacitors are also crucial to the correct working of nearly every
electronic circuit and provide us with a means of storing electrical energy in the form of
an electric field. Capacitors have numerous applications including storage capacitors in
power supplies, coupling of A.C. signals between the stages of an amplifier, and
decoupling power supply rails so that, As far as A.C. signal components are concerned,
the supply rails are indistinguishable from zero volts.

TYPES OF CAPACITORS:
DISC CAPACITORS :

- 38 -
 In the disk form, silver is fired on to both sides of the ceramic to form the conductor
plates. The sheets are then baked and cut to the appropriate shape and size & attached by
pressure contact and soldering . These have high capacitance per unit volume and are
very economical. The disks are lacquered or encapsulated in plastic or Phenolic molding.
Round disk are used at high voltages the capacitance of values upto 0.01F can be
obtained. They have tolerance of +20% or –20%. In general these capacitors have
voltage ratings up to 750 V D.C.

 ELECTROLYTIC CAPACITORS :

These capacitors derive the name from electrolyte which is used as a medium to produce
high dielectric constants. These capacitors have low value for large capacitances at low
working voltages.
There are two types of Electrolytic capacitors:
 Aluminum Electrolytic capacitors.  Tantalum electrolytic
capacitors

Electrolytic capacitors are used in circuits that have combination of D.C. voltage and
A.C. The D.C. voltage maintains the polarity . They are used as ‘ripple filter ‘ where
large capacitance are required at low cost in small space . They are also used as ‘biased
capacitors ‘ and ‘decoupling capacitors ‘ and even as ‘coupling capacitors ‘ in R- C
amplifier.

 COLOR CODING :

- 39 -
 Mica and tubular ceramic capacitors are color coded to indicate a capacitance value . As
coding is necessary only for very small sizes, color coded capacitors value is also in the
pF. The colors are the same as for the resistor coding from black for ‘0’ upto white for
‘9’. Mica capacitors use ‘six dot code system’.

 SIX DOT CODE :

Here the top row is read from the left to right and the bottom from right to left .The dot
indicates the following:
(1) . White . (2). Digit . (3). Digit. (4) . Multiplier. (5) . Tolerance . (6) . Class.

White for the first dot indicates the coding. The capacitance value is read from the next
three dots . If the first dot is silver it indicates paper capacitor. The white colored band
indicates the left and specifies the temperature coefficient . The next three colors indicate
the value of capacitance. For example Brown, Black, Brown = 100 pF.

 DIODES:

To ensure unidirectional flow of liquid we use mechanical valves in its path. By properly
arranging these valves in a system we get useful devices such as pumps and locomotives. In
the field of electronics too we have a valve called semiconductor diode (a counterpart of
thermionic valve) for controlling the flow of electric current in one direction. But we use these
diodes in circuits for limited purposes like converting AC to DC, by passing EMF etc. a diode
allows current to pass through it provided it is forward biased and the biasing voltage is more
than potential barrier (forward voltage drop) of the diode.

TRANSISTOR:

- 40 -
The transistor an entirely new type of electronic device is capable of achieving amplification of
weak signals in a fashion comparable and often superior to that realized by vacuum tubes.
Transistors are far smaller than vacuum tube, have no filaments and hence need no heating
power and may be operates in any position. They are mechanically strong, hence practically
unlimited life and can do some jobs better than vacuum tubes.

Invented in 1948 by J. Bardeen and W.H.Brattain of Bell Telephone Laboratories, a

transistor has now become the heart of most electronic appliance. Though transistor is
only slightly more the 45 years old, yet it is fast replacing vacuum tubes in almost all
applications.

A transistor consists of two pn junction formed by sand witching either p-type or n-type
semiconductor between a pair of opposite type. Accordingly, there are two types of
transistors namely:

 n-p-n transistor
 p-n-p transistor

An n-p-n is composed of two n-type semiconductors separated a by thin section of p-

type. However, a p-n-p is formed by two p-section separated by a thin section of n-type.
 These are two pn junctions. Therefore, a transistor may be regarded as a combination of
two diodes connected back to back.
 There are 3 terminals, taken from each type of semiconductor.
 The middle section is very thin layer. This is the most important factor in the functioning
of a transistor.

Origin of the name “transistor “: When new devices are invented, scientists often try to
device a name that will appropriately describe the device. A transistor has two pn
junctions. As the discussed later one junction is forward biased and the other is reversed
biased. The forward biased junction has low resistance path whereas the reverse biased
- 41 -
 junction has low resistance path whereas the reverse biased junction has a high
resistance path. The weak signal is introduced in the low resistance circuit and output is
taken from the high resistance circuit. Therefore, a transistor transfers a signal from a
low resistance to high resistance. The prefix ‘tans’ means the signal transfer property of
the device while
‘istor’ classifies it as a solid element in the same general family with resistors.

NAMING THE TRANSISTOR TERMINALS:

A transistor (pnp or npn) has three sections of doped semiconductors. The section on one
side is the emitter and the section on the opposite side is the collector. The middle
section is called the base and forms two junctions between the emitter and collector.

 Emitter: - The section on one side that supplies charge carriers (electrons or holes) is
called the emitter. The emitter is always forward biased w.r.t base so that it can supply a
large number of majority carriers.
 Collector: - The section on the other side that collects the charge is called the collector.
The collector is always reversing biased. Its function is to remove charges from its
junction with the base.
 Base: - The middle section, which forms to pn junctions between the emitter and
collector, is called base. The base emitter junction is forward biased, allowing low
resistance for the emitter circuit. The base-collector junction is reversed biased and
provides high resistance in the collector circuit.

 CHARACTERISTICS OF TRANSISTORS
Whenever we have to decide about the applications of a transistor certain question arises.
Some of these are – how much amplification gets from it? What is the highest frequency
upto which it can be used? How much power output could we get from it? And what
should be the values of different components used in the circuits? The answers to these
entire questions lie in the electrical properties of the transistor. These properties depend
on the size, manufacturing techniques and materials used in the manufacturer of
transistor and are know as characteristics. Transistor manufacturers give these
characteristics in the data sheets published by them.

 Current gain factor ‘alpha’ ()

 Current gain factor ‘beta’ ()

 Input resistance (Rin)

- 42 -
  Output resistance (Rout)

 Cut-off frequency (F  and F)

 Leakage current (I )
 Maximum permissible limits:

1. Maximum collector voltage (Vceo)

2. Maximum emitter current (IC Max)
3. Maximum Power dissipation (P max)

RELAY:

A relay is an electrically operated switch. Many relays use an electromagnet to operate a

switching mechanism mechanically, but other operating principles are also used. Relays
are used where it is necessary to control a circuit by a low-power signal (with complete
electrical isolation between control and controlled circuits), or where several circuits
must be controlled by one signal. The first relays were used in long distance telegraph
circuits, repeating the signal coming in from one circuit and re-transmitting it to another.
Relays were used extensively in telephone exchanges and early computers to perform
logical operations.

A type of relay that can handle the high power required to directly drive an electric motor
is called a contactor. Solid-state relays control power circuits with no moving parts,
instead using a semiconductor device to perform switching. Relays with calibrated
operating characteristics and sometimes multiple operating coils are used to protect
electrical circuits from overload or faults; in modern electric power systems these
functions are performed by digital instruments still called "protective relays".

BASIC DESIGN AND OPERATION:

A simple electromagnetic relay consists of a coil of wire surrounding a soft iron core, an
iron yoke which provides a low reluctance path for magnetic flux, a movable iron
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armature, and one or more sets of contacts (there are two in the relay pictured). The
armature is hinged to the yoke and mechanically linked to one or more sets of moving
contacts. It is held in place by a spring so that when the relay is de-energized there is an
air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the
relay pictured is closed, and the other set is open. Other relays may have more or fewer
sets of contacts depending on their function. The relay in the picture also has a wire
connecting the armature to the yoke. This ensures continuity of the circuit between the
Moving contacts on the armature, and the circuit track on the printed circuit board (PCB)
via the yoke, which is soldered to the PCB.

When an electric current is passed through the coil it generates a magnetic field that
attracts the armature, and the consequent movement of the movable contact(s) either
makes or breaks (depending upon construction) a connection with a fixed contact. If the
set of contacts was closed when the relay was de-energized, then the movement opens
the contacts and breaks the connection, and vice versa if the contacts were open. When
the current to the coil is switched off, the armature is returned by a force, approximately
half as strong as the magnetic force, to its relaxed position. Usually this force is provided
by a spring, but gravity is also used commonly in industrial motor starters. Most relays
are manufactured to operate quickly. In a low-voltage application this reduces noise; in a
high voltage or current application it reduces arcing.

When the coil is energized with direct current, a diode is often placed across the coil to
dissipate the energy from the collapsing magnetic field at deactivation, which would
otherwise generate a voltage spike dangerous to semiconductor circuit components.
Some automotive relays include a diode inside the relay case. Alternatively, a contact
protection network consisting of a capacitor and resistor in series (snubber circuit) may
absorb the surge. If the coil is designed to be energized with alternating current (AC), a
small copper "shading ring" can be crimped to the end of the solenoid, creating a small
out-of-phase current which increases the minimum pull on the armature during the AC
cycle.

A solid-state relay uses a thyristor or other solid-state switching device, activated by the
control signal, to switch the controlled load, instead of a solenoid. An optocoupler (a
light-emitting diode (LED) coupled with a photo transistor) can be used to isolate control
and controlled circuits.

Introduction To Integrated Circuits:

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 All modern digital systems rely on the use of integrated circuits in which hundreds of
thousands of components are fabricated on a single chip of silicon. A relative measure of
the number of individual semiconductor devices within the chip is given by referring to
its ‘scale of integration’. The following terminology is commonly applied.

Scale of integration Abbreviation Number of logic gates

Small SSI 1 to 10
Medium MSI 10 to 100
Large LSI 100 to 1000
Very large VLSI 1000 to 10,000
Super large SLSI 10,000 to 100,000
Encapsulation:

The most common package used to encapsulate an integrated circuit, and that with which
most reader will be familiar, is the plastic dual-in-line (DIL) type. These are available
with a differing number of pins depending upon the complexity of the integrated circuit
in question and, in particular, the need to provide external connections to the device.
Conventional logic gates, for example, are often supplied in 14-pin or 16-pin DIL
packages, whilst microprocessors (and their more complex support devices) often
require 40-pins or more.

Identification:

When delving into an unfamiliar piece of equipment, one of the most common problems
is that of identifying the integrated circuit devices. To aid us in this task, manufacturers
provide some coding on the upper surface of each chip. Such a coding generally includes
the type number of the chip (including some of the generic coding), the manufacturer’s
name (usually in the form of prefix letters), and the classification of the device (in the
form of a prefix, infix or suffix).

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In many cases the coding is further extended to indicate such things as encapsulation,
date of manufacture, and any special characteristics of the device. Unfortunately, all of
this potentially useful information often leads to some considerable confusion due to
inconsistencies in marking from one manufacturer to the next!
Logic Families:
The integrated circuit device on which modern digital circuitry depends belongs to one
or other of several ‘logic families’. The term simply describes the type of semiconductor
technology employed in the fabrication of the integrated circuit. This technology is
instrumental in determining the characteristics of a particular device. This, however, is
quite different from its characteristics, and encompasses such important criteria as
supply voltage, power dissipation, switching speed and immunity to noise.

The most popular logic families, at least as far as the more basic general purpose devices
are concerned, are complementary metal oxide semiconductor (CMOS) and transistor
transistor logic (TTL). TTL also has a number of sub-families including the popular low
power Schottky (LS-TTL) variants.

The most common range of conventional TTL logic devices is known as the ‘74’ series.
These devices are, not surprisingly, distinguished by the prefix number 74 in their
coding. Thus devices coded with the numbers 7400, 7408, 7432 and 74121 are all
members of this family which is often referred to as ‘Standard TTL’. Low power
Schottky variants of these devices are distinguished by an LS infix. The coding would
then be 74LS00, 74LS08, 74LS32 and 74LS121.

Popular CMOS devices from part of the ‘4000’ series and are coded with an initial prefix
of 4. Thus 4001, 4174, 4501 and 4574 are all CMOS devices. CMOS devices are
sometimes also given a suffix letter; A to denote the ‘original’ (now obsolete) unbuffered
series, and B to denote the improved (buffered) series. A UB suffix denotes an
unbuffered B-series device

Infix letters Meaning

C CMOS version of a corresponding TTL device

F ‘Fast’ – a high speed version of the device

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H High speed version
S Schottky (a name resulting from the input circuit Configuration)
HC High speed CMOS version (with CMOS compatible inputs)
HCT High speed CMOS version (with TTL compatible inputs)

CHAPTER 4

PCB DESIGNING & SOLDERING TECHNIQUES

PCB DESIGNING:

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1. Design your circuit board. Use PCB computer-aided design (CAD) software to draw
your circuit board. You can also use a perforated board that has pre-drilled holes in it to
help you see how your circuit board's components would be placed and work in reality.
2. Buy a plain board that is coated with a fine layer of copper on one side from a retailer.
3. Scrub the board with a scouring pad and water to make sure the copper is clean. Let the
board dry.
4. Print your circuit board's design onto the dull side of a sheet of blue transfer paper. Make
sure the design is oriented correctly for transfer.
5. Place the blue transfer paper on the board with the circuit board's printed design against
the copper.
6. Lay a sheet of ordinary white paper over the blue paper. Following the transfer paper's
instructions, iron over the white and blue paper to transfer the design onto the copper
board. Iron every design detail that appears near an edge or corner of the board with the
tip of the iron.
7. Let the board and blue paper cool. Peel the blue paper slowly away from the board to see
the transferred design.
8. Examine the transfer paper to check for any black toner from the printed design that
failed to transfer to the copper board. Make sure the board's design is oriented correctly.
9. Replace any missing toner on the board with ink from a black permanent marker. Allow
the ink to dry for a few hours.
10. Remove exposed parts of the copper from the board using ferric chloride in a process
called etching.
11. Put on old clothes, gloves and safety goggles.

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 12. Warm the ferric chloride stored in a non-corrosive jar and sealed with a non-corrosive
lid, in a bucket of warm water. Do not heat it above 115 F (46 C) to prevent toxic fumes
from being released.
13. Pour only enough ferric chloride to fill a plastic tray that has plastic risers in it to rest the
circuit board on. Be sure to do this in a well-ventilated space.
14. Use plastic tongs to lay the circuit board face down on the risers in the tray. Allow 5 to
20 minutes, depending on the size of your circuit board, for the exposed copper to drop
off the board as it etches away. Use the plastic tongs to agitate the board and tray to allow
for faster etching if necessary.
15. Wash all the etching equipment and the circuit board thoroughly with plenty of running
water.
16. Drill 0.03 inch (0.8 mm) lead component holes into your circuit board with high-speed
steel or carbide drill bits. Wear safety goggles and a protective mask to protect your eyes
and lungs while you drill.
17. Scrub the board clean with a scouring pad and running water. Add your board's electrical
components and solder them into place.

SOLDERING TECHNIQUES

Soldering is the only permanent way to ‘fix’ components to a circuit. However, soldering
requires a lot of practice as it is easy to ‘destroy’ many hours preparation and design
work by poor soldering. If you follow the guidelines below you have a good chance of
success

Use a soldering iron in good condition. Inspect the tip to make sure that it is not past
good operation. If it looks in bad condition it will not help you solder a good joint. The

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shape of the tip may vary from one soldering iron to the next but generally they should
look clean and not burnt.

A PCB eraser is used to remove any film from the tracks. This must be done carefully
because the film will prevent good soldering of the components to the PCB. The track
can be checked using a magnified glass. If there are gaps in the tracks, sometimes they
can be repaired using wire but usually a new PCB has to be etched

The heated soldering iron should then be placed in contact with the track and the
component and allowed to heat them up. Once they are heated the solder can be applied.
The solder should flow through and around the component and the track. Having
completed soldering the circuit the extended legs on the components need to be trimmed
using wire clippers. The circuit is now ready for testing.

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Hardware Implementation

Simulation

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Result-

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- 53 -
 Future scope

Safety concerns
• Do not connect power to a circuit until the circuit is finished and you have carefully checked
your work.
• If you smell anything burning, immediately disconnect the power and examine your circuit to
find out what went wrong.
• Keep your work area dry.
• Always wear safety goggles.
• Be careful around large capacitors; they can continue to hold voltage long after they are
disconnected from power.
• Be especially careful when you solder because a hot soldering iron can easily burn you.
• Always work in a well-ventilated space.
• Have safety equipment such as a fire extinguisher, a first-aid kit, and a phone nearby

Advantages of Electric Vehicles to the Grid

As part of the ongoing evolution of electric vehicles, the concept of Electric Vehicles to the Grid
(V2G), studies the interaction between large loads of electric vehicles and grid, is also a topic of
discussion. hot research in the field of smart grids and electric vehicles. It was realized that if the
EV charging process could be optimized, it could bring many benefits to the network. EVs can
balance loads by filling valleys and clipping peaks. An electric vehicle battery is like a power bank,
so some unstable new energy sources, such as wind power, can be more easily connected to the
grid

Conclusion
In this synopsis, EVs with the capability of V2G/G2V operation are integrated in the distribution
grid. A mathematical model of V2G/G2V power control is formulated, which incorporates EV
models into power grid optimization. The V2G/G2V optimization method is proposed to schedule
the EV charging and discharging energy to minimize the operating cost while satisfying the mobility
needs and power system limitations. In addition to V2G/G2V optimal energy scheduling, EVs are
also deployed for dynamic power regulation, which requires fast response to the instantaneous
imbalance between the power supply and demand. V2G/G2V power is controlled to mitigate the
power fluctuation and, thus, stabilize the system frequency and voltage. The simulation results verify
effective utilization of V2G/G2V power for multiple purposes. Finally, the hardware-in-the-loop

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system is developed to implement software simulation by regulating power converters, and the
measured results validate the simulation model

REFERENCES

1. "ARM7DI Data Sheet"; Document Number ARM DDI 0027D; Issued: Dec 1994.
2. Sakr, Sharif. "ARM co-founder John Biggs". Engadget. Retrieved December 23, 2011.
"[...] the ARM7-TDMI was licensed by Texas Instruments and designed into the Nokia
6110, which was the first ARM-powered GSM phone."
3. "D-Link DSL-604+ Wireless ADSL Router - Supportforum -
eXpansys
Sverige". 090506 expansys.se
4. Andrew (bunnie) Huang. "On MicroSD Problems". Bunnie Studios. "This is comparable
to the raw die cost of the controller IC, according to my models; and by making the
controllers very smart (the Samsung controller is a 32-bit ARM7TDMI with 128k of
code), you get to omit this expensive test step while delivering extra value to customers"

5. ARM Architecture Reference Manual.

6. Electronic Communication Systems – George Kennedy
7. Electronics in Industry - George M.Chute
8. Principles of Electronics - V.K.Mehta
9. www.electronicsforu.com
10. www.howstuffworks.com
11. Telecommunication Switching, Traffic and Networks – J.E.Flood

Hanjiang Luo, Kaishun Wu, Zhongwen Guo, Lin Gu, Zhong Yang and Lionel M. N
“SID: Ship Intrusion Detection with Wireless Sensor Networks” International
Conference on Distributed Computing Systems.

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