Smart Charge Management of Electric

Vehicles in Power Grid

A project report on the partial fulfilment of the requirement for the degree of

BACHELOR OF TECHNOLOGY
In
ELECTRICAL ENGINEERING
by
Gyanesh Chandra Das Reg.No:20202057
Mahendra Singh Reg. No.: 20212013
Goutam Jangid Reg. No.: 20212012

Under the supervision of

Dr. Prashant Kumar Tiwari

(Electrical Engineering Department)

DEPARTMENT OF ELECTRICAL ENGINEERING,

MOTILAL NEHRU NATIONAL INSTITUTE OF TECHNOLOGY
ALLAHABAD

PRAYAGRAJ 211004
 ACKNOWLEDGEMENT
It is a great pleasure to express our sincere gratitude and profound regards to
our project work supervisor Prof. Prasant Kumar Tiwari, Electrical Engineering
Department, MNNIT Allahabad, for her constant encouragement, valuable guidance,
motivation, support, advice, and supervision during the entire course of the work.
Her meticulous guidance, constructive, and valuable suggestions, timely discussion
and clarification of our doubts increased our cognitive awareness and helped us for
making a deeper analysis of the subject under study. Our association with her
throughout the thesis activity was a great process of learning.

Thank is also due to, Prof. Prasant Kumar Tiwari, professor of Electrical
Engineering Department, MNNIT for providing facilities and advice needed to
complete the work.

We also express our heartful gratitude to the Department of Electrical

Engineering MNNIT Allahabad for giving us this opportunity, which has enriched
our knowledge and experience immensely.

Last but not the least my head bows with reverence before Almighty GOD,
who has given us strength, wisdom and will to complete the work.

Gyanesh Chandra Das (20212057)

Mahendra Singh (20212013)
Goutam Jangid (20212012)
 Table of the content
Page No.

Undertaking 2

Certificate 3

Acknowledgement 4

List of Content 5

CHAPTER 1: ABSTRACT 6

CHAPTER 2: INTRODUCTION 6

CHAPTER 3: OBJECTIVE 7

CHAPTER 4: METHODOLOGIES 7

CHAPTER 5: Vehicle to Grid Technology 8

CHAPTER 6: Grid Connected Inverter and LCL Filter 9

CHAPTER 7: Off-Board Charger Control 9

CHAPTER 8: RESULTS 12

CHAPTER 9: 24 hours V2G Simulation 14

CHAPTER 10: WORK PLAN 15

CHAPTER 11: REFERENCES 15

ABSTRACT
This report explores the challenges associated with integrating large numbers of electric
vehicles (EVs) into low and medium voltage networks. It synthesizes current knowledge, research
findings, and key issues in determining the hosting capacity for EVs. The analysis considers various
factors, including renewable energy generation, ambient temperature, large -scale charging
installations, and dynamic line ratings. By addressing these aspects, the report provides insights into
 optimizing EV integration while ensuring grid stability and efficiency in response to the growing
demand for electrification.

The rapid growth of electric vehicles (EVs) presents new challenges and opportunities for
power grid management. Smart charging, which involves the intelligent scheduling and control of EV
charging, is essential for ensuring grid stability, reducing peak load stress, and maximizing the use of
renewable energy sources. This paper explores the implementation of smart charging strategies,
focusing on coordinated charging and Vehicle-to-Grid (V2G) technology. Coordinated charging
optimizes charging schedules based on grid demand, reducing the risk of overloading and enhancing
grid efficiency. V2G enables bidirectional energy flow, allowing EVs to act as mobile energy storage
units, returning energy to the grid during peak periods and supporting grid stability. Together, these
technologies contribute to a more resilient, cost-effective, and sustainable energy system. However,
infrastructure upgrades, standardization, and policy frameworks are crucial for their widespread
adoption. This study emphasizes the potential of smart charging to transform the interaction between
EVs and the power grid, facilitating the integration of renewable energy and contributing to a greener
future.

INTRODUCTION
______________________________________________________________________
Integrating electric vehicles (EVs) with the electrical grid presents challenges and opportunities for grid
stability, energy management, and sustainability. Smart charging solutions play a key role by optimizing
charging patterns, balancing demand, and increasing renewable energy use. This summary highlights the
transformative potential of EVs as active grid participants, enhancing flexibility and efficiency, and
contributing to a more sustainable, cost-effective energy system powered by cleaner sources. The focus
is on understanding the evolving relationship between EVs and the grid for a resilient energy future.

As the world moves towards cleaner energy solutions, electric vehicles (EVs) are gaining widespread
adoption due to their potential to reduce greenhouse gas emissions and reliance on fossil fuels. However,
the increasing number of EVs poses significant challenges for existing power grids, particularly during
peak demand hours. Uncontrolled charging can lead to grid overload, voltage fluctuations, and increased
infrastructure costs. To mitigate these issues, smart charging solutions are being developed to optimize
the way EVs interact with the grid.

Smart charging involves the intelligent management of EV charging times and rates to balance grid demand,
reduce stress on the infrastructure, and maximize the use of renewable energy. Key components of smart
charging include coordinated charging, where charging schedules are adjusted based on grid conditions,
and Vehicle-to-Grid (V2G) technology, which allows EVs to return energy to the grid when needed.

Impact of Electrical vehicle charging on power grid

• Grid Overload: The rapid increase in EV adoption can overwhelm existing grid infrastructure,
especially during peak charging times, leading to power outages or the need for costly upgrades.
• Voltage Fluctuations: Uncontrolled EV charging can cause voltage imbalances and fluctuations
in local grids, negatively impacting power quality and reliability.
• Higher Energy Costs: Increased demand from EVs can raise electricity prices, especially if
additional generation capacity or grid reinforcements are needed to meet the load.
• Renewable Energy Mismatch: Without smart charging coordination, EVs may increase reliance
on non-renewable energy during peak demand periods, undermining sustainability efforts.
• Strain on Distribution Systems: Localized clusters of EVs, such as in residential areas, can
stress distribution transformers and power lines, accelerating wear and leading to premature
failures.

OBJECTIVE
______________________________________________________________

The primary objective of this study is to explore and analyze the implementation of
smart charging strategies for electric vehicles (EVs) to ensure efficient integration
into the power grid. Specifically, this report aims to:

1. Optimize Charging Patterns: Investigate methods to manage EV charging schedules,

minimizing grid overload and reducing peak electricity demand through coordinated
charging.

2. Integrate Vehicle-to-Grid (V2G) Technology: Assess the potential of V2G

technology for enabling bidirectional energy flow, allowing EVs to supply power
back to the grid during periods of high demand, improving grid stability and
resilience.

3. Maximize Renewable Energy Usage: Identify ways to align EV charging with the
availability of renewable energy sources, such as solar and wind, to create a more
sustainable energy system.

4. Reduce Infrastructure Strain: Propose solutions to manage EV charging in a way

that minimizes the need for costly upgrades to existing electrical infrastructure.
 5. Promote Economic and Environmental Benefits: Evaluate the economic incentives
for EV owners and the environmental impact of smart charging and V2G
technologies, promoting energy efficiency and lower carbon emissions.

METHODOLOGIES
a) Implementation of Vehicle-to-Grid (V2G) and Grid-to-Vehicle (G2V) Technologies in a
Microgrid
b) Design of Off-Board Charger Control and Inverter Control for Electric Vehicles
c) 24-Hour Simulation of Vehicle-to-Grid (V2G) Operation.

4.1 Vehicle to Grid Technology

Electric Vehicle (EV) batteries can be utilized as potential energy storage devices in
micro-grids. They can help in micro-grid energy management by storing energy when
there is surplus (Grid-To-Vehicle, G2V) and supplying energy back to the grid (Vehicle-
To-Grid, V2G) when there is demand for it. Proper infrastructure and control systems
have to be developed in order to realize this concept. A micro-grid test system is
modeled which has a dc fast charging station for interfacing the EVs. Simulation studies
are carried out to demonstrate V2G-G2V power transfer. Test results show active power
regulation in the micro-grid by EV batteries through G2V-V2G modes of operation. The
charging station design ensures minimal harmonic distortion of grid injected current and
the controller gives good dynamic performance in terms of dc bus voltage stability.

2.1.1. Battery Charger Configuration

For dc fast charging, the chargers are located off-board and are enclosed in an EVSE. It
consists of two IGBT/MOSFET switches that are always operated by complimentary control
signals.

1. Buck mode of operation (charging mode): When the upper switch (S(buck)) is operating, the
converter acts as a buck converter stepping down the input voltage(V(ac)) to battery charging
voltage(V(batt)).
2. Boost mode of operation (discharging mode): When the lower switch (S(boost) is operating, the
converter acts as a boost converter stepping up the battery voltage (V(batt) to the dc bus voltage (V(dc)).
When the switch is in on state, current continues to flow through the inductor and completes its circuit
through the anti-parallel diode of the upper switch, and the capacitor. The net power flow in this case is
from the vehicle to the grid (V2G) and the battery operates in the discharge mode.

2.2 Grid Connected Inverter and LCL Filter

The grid connected inverter (GCI) converts the dc bus voltage into a three-phase ac voltage and
also allows the reverse flow of current through the anti-parallel diodes of the switches in each leg
(Fig. 1). An LCL filter is connected at the output terminals of the inverter for harmonic reduction
and obtaining a pure sinusoidal voltage and current.

3.1 Off-Board Charger Control :

A constant current control strategy [5] using PI controllers is implemented for charge/discharge
control of the battery charger circuit a is shown in Fig.3. The controller first compares the reference
battery current with zero, in-order to determine the polarity of the current signal, to decide between
charging and discharging modes of operations.
3.2 . Inverter Control:
A cascade control in synchronous reference frame is proposed for the inverter controller. The
conventional standard vector control using 4 PI controllers in a nested loop is shown in Fig. 4
[4]. The control structure consists of two outer voltage control loops and two inner current
control loops.

4. MICRO-GRID TEST SYSTEM CONFIGURATION:

The micro-grid test system configuration with the dc fast charging station is shown in Fig. 5. A
100-kW wind turbine (WT) and a 50-kW solar PV array serve as the generation sources in the
system. The EV battery storage system consists of 4 EV batteries connected to a 1.5 kV dc bus of the
charging station through off-board chargers. The solar PV is also connected to this dc bus through a boost
converter which has a maximum power point tracking (MPPT) controller. The utility grid consists of a 25
kV distribution feeder and a 120 kV equivalent transmission system.The wind turbine driven doubly-fed
induction generator is connected to the micro-grid at the point of common coupling (PCC
5. SIMULATION RESULTS:
Vehicle to Grid (V2G) Operation: During the V2G operation, the graph depicting voltage,
current, and state of charge (SOC) shows a gradual decrease in voltage, an increase in current,
and a decrease in the SOC. This indicates that energy is being transferred from the electric
vehicle to the grid. The operation occurs between 1-4 seconds, while the system returns to a
normal steady-state condition before and after this operation.

Grid to Vehicle (G2V) Operation: The G2V operation is represented by the graph showing
voltage, current, and SOC. It demonstrates a gradual increase in voltage, a decrease in current,
and an increase in the SOC. This indicates that energy is being transferred from the grid to the
electric vehicle. The G2V operation takes place between 4-6 seconds, while the system remains
in a steady- state condition before and after this operation
6. 24-Hour Simulation of Vehicle-to-
Grid (V2G) Operation

The model presented in this part of the work represents a micro grid
that is fed through a diesel generator, in addition to a PV farm and a
wind farm. The diesel generator is the main power generator in this
micro grid with an active power equal to 15 MW. The renewable
energy is produced by a combination of Photovoltaic (PV) and wind
farms.
 CONCLUSION

In conclusion, the global shift towards renewable energy and electric

vehicles has heightened the need for innovative integration solutions, with
microgrids emerging as a viable option. The implementation of Grid to
Vehicle (G2V) and Vehicle to Grid (V2G) technologies through Level 3
DC fast charging stations and advanced power electronics can enhance
the efficiency and sustainability of microgrids. A simulation study
conducted using MATLAB Simulink demonstrates the effectiveness of
these technologies in regulating active power and minimizing frequency
deviations. Ultimately, the successful deployment of G2V and V2G can
contribute to a more reliable and sustainable energy system that addresses
increasing energy demands while reducing greenhouse gas emissions.

WORK PLAN

• Implementing and analyzing 24-Hour Simulation of Vehicle-to-Grid (V2G) Operation.

• AI driven optimization for EV charging Schedules.
• Use of Machine Learning algorithm in predictive modelling
• Reinforcement Learning and genetic Algorithms for optimization of EV charging Schedules to
maximize.

REFERANCES
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and simulation of V2G system in micro-grid,” in Proceedings of the
International Conference on Electrical Machines and Systems, ICEMS 2011,
2011, pp. 1–4.
• S. Han, S. Han, and K. Sezaki, “Development of an optimal vehicle-togrid
aggregator for frequency regulation,” IEEE Trans. Smart Grid, vol. 1, no. 1, pp.
65–72, 2010.
• M. C. Kisacikoglu, M. Kesler, and L. M. Tolbert, “Single-phase on-board
bidirectional PEV charger for V2G reactive power operation,” IEEE Trans.
Smart Grid, vol. 6, no. 2, pp. 767–775, 2015.
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improvement for vehicle-to-grid and grid-to-vehicle technology in a micro grid.
International Transactions on Electrical Energy Systems, 2022.
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for fast DC charging,” in Proceedings of the IEEE International Electric Vehicle
Conference (IEVC), 2012, pp. 1–6
• K. M. Tan, V. K. Ramchandaramurthy, and J. Y. Yong, “Bidirectional battery
charger for electric vehicle,” in 2014 IEEE Innovative Smart Grid Technologies
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• G. Eragamreddy and S. G. Naik, "Modeling and Simulation of Solar Energy
Storage System for Electric Vehicle," 2022 International Conference on
Futuristic Technologies (INCOFT), Belgaum, India, 2022, pp. 1-5, doi:
10.1109/INCOFT55651.2022.10094323.
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Modulation Techniques for Renewable Energy Applications. Turkish Journal of
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