TRANSFORMERLESS MULTISTRING switching scheme for LLC series-resonant
FIVE-LEVEL INVERTER USING PWM half-bridge (SRHB) dc-dc converter. The
CONTROL SCHEME FOR PV concept proposed hybrid switching scheme
APPLICATIONS
is changing the switching mode to improve
S. Annapoorani, P. Radika, J. Baskaran power efficiency in a wide load range. The
SRHB converter operates in three different
Abstract—This paper presents a single switching modes depending on the output
phase multistring converter and five-level load condition. This three switching
photovoltaic (PV) inverter topology for schemes provides efficient operation of
grid-connected PV systems with a pulse system at different load condition. The
width-modulated (PWM) control scheme. simulation and Digital control of the
The quadratic converter steps up the low
system facilitates the implementation of
dc voltage of the PV string to a dc voltage
which is greater than √2 times the grid the proposed hybrid switching. Hence high
voltage and eliminates the need of the efficiency is achieved with a constant
transformer. Three PV strings are output voltage over wide load range.
cascaded together in parallel
configuration with their own quadratic
converter and connected to a five-level A SOFT-SWITCHING DC/DC
inverter to produce output voltage in five CONVERTER WITH HIGH
levels: zero, +1/2Vdc,Vdc, -1/2Vdc, and VOLTAGE GAIN
-Vdc. Two reference signals that are
identical to each other with an offset that
Ms. M. Indira priyadarshini, Mrs. S.
is equivalent to the amplitude of the
triangular carrier signal are used to Komala chitra, Mr. P. Moorthy
generate PWM signals for the switches. A Madha Engineering College, Chennai
digital proportional–integral current Email-
control algorithm is used. The inverter m_indirapriyadarshini@yahoo.co.in
offers much less total harmonic distortion
and can operate at near-unity power
factor. The validity of the proposed Abstract- This Paper Presents a Soft-
converter and inverter is verified through Switching DC/DC Converter with High
simulation. Voltage Gain. The soft switching
characteristic of the proposed converter
A Hybrid Switching Scheme for LLC
reduces switching loss of active power
series-Resonant Half-bridge DC-DC
switches and raises the conversion
Converter in a Wide Load Range
efficiency. The reverse recovery problem of
A.G.karthikeyan,
R.Annadurai output rectifiers is also alleviated by
Arunai Engineering College, Tiruvannamalai controlling the current changing rates of
Email: Karthik4988@gmail.com diodes with the use of leakage inductance
Email:rad_mtech@yahoo.co.in of a coupled inductor. Zero voltage
switching is used for the switches in boost
Abstract — This project presents a hybrid mode operation during turn on and turns
off condition to reduce the switching losses B.Jayanthi, S.A.Elankurisil ,J.Baskaran
during the transition and improves the Adhiparasakthi Engineering College
overall efficiency. The efficiency of the Abstract - This paper presents a novel
Series Resonant dc-dc converter using Z-
proposed soft switching dc-dc converter is
source impedance network. The
verified by experimental results and the conventional series resonant converter
feasibility of the proposed circuits can be suffers from efficiency degradation
verified by PSPICE simulation. problem when the input voltage range is
wide because the switching frequency of
converter should be increased far away
from resonant frequency to control output
A Double-Ended ZeroVoltage Switching voltage. The proposed Z-source resonant
Full-Bridge Zeta Converter dc-dc converter can minimize switching
frequency range of the converter and can
R.Leelavathy ,S.Sugumar lead to high converter efficiency over the
Madha Engineering College, entire input voltage and load variation. In
addition to that, the proposed converter
E-mail ID:leelaraj87@gmail.com can be short- and open-circuited without
damaging switching devices. Thus the
proposed converter is very strong to EMI
Abstract —A new double-ended type zero- and converter reliability can be greatly
voltage switching (ZVS) full-bridge zeta enhanced. Finally, bulky inductors and
(FBZ) converter employing a double-ended capacitors in the Z-source network are
rectifier (DER) is proposed. The proposed reduced significantly while maintaining
DER for the FBZ converter provides a the same converter performance.
bidirectional powering path in the rectifier.
As a result, the improved voltage waveform
of the rectifier reduces the output filter
size and voltage stresses on rectifier CONSERVATION OF ENERGY
components. Moreover, it offers a wide ZVS LOSSES IN SNUBBERS THROUGH
range. In addition, to minimize the UNIQUE ENERGY RECOVERY
secondary snubber loss, a simple lossless METHOD
snubber is adopted. The operational K. R. NITHIYAA, Mr.T.ARUN SRINIVAS
principles and characteristics of the Jeppiaar engineering college
proposed converter are to be analyzed and Email Id: krnithiyaa@gmail.com
verified experimentally.
ABSTRACT: The structure utilizes a
passive soft-switching snubber (PSSS)
Z-SOURCE BASED SERIES
RESONANT CONVERTER FOR employs a snubber circuit consisting of
HIGH-POWER LOW-VOLTAGE
diodes and capacitors for each phase leg to
FUEL CELL APPLICATIONS
provide low dv/dt and low switching losses
to the switching devices and to realize be more appropriate. Design of fuzzy
soft switching operation over a wide line controllers is based on heuristic knowledge
of converter behavior. The controller is
and load range . All primary side switches
designed to regulate the duty cycle of the
are operated with zero-current switching converter to control the output voltage.
(ZCS) and the snubber switches are The proposed fuzzy controller is evaluated
by computer simulation using
operated with zero- voltage switching. The
MATLAB/SIMULINK software
energy used for soft- switching is self-
adaptable. This paper proposes a new Space Vector Modulation for
snubber that is inserted in the primary Unidirectional PWM Rectifiers
side of a current-driven FB converter. ZCS A.Anitha , J. Baskaran, N.Hemalatha
of the power switches is obtained at a very Adhiparasakthi Engineering College
wide line and load range starting from a E-mail: aniarunachalam@gmail.com
low value of the input current, by always
Abstract— This paper presents the
using the minimum necessary energy. concepts for application of space vector
The snubber switches are operated with modulation to two-level unidirectional
pulse width modulation (PWM) rectifiers
ZVS. A properly snubbed circuit enhances
and a methodology for the use of this
system reliability, is more efficient, than an modulation is proposed and applied in
un snubbed circuit. three different groups of rectifiers. For
each group of rectifiers, the converter
switching stages are analyzed to
determine switch control signals for space
FLC BASED CLOSED LOOP CONTROL OF vector modulation. One switching
DC-DC CONVERTER sequence is proposed for all rectifiers in
order to minimize the number of switch
F.T. Josh , Elizabeth Rajan commutations and reduce the switching
School of Electrical Sciences losses. Duty cycle functions are determined
Karunya University ,Coimbatore and the desired switching sequences are
Email id: josh@karunya.edu, performed by a simple PWM, without the
eliz87rose@gmail.com need to determine the present sector of the
vector. For this purpose, it is necessary to
Abstract- This paper proposes the design impose the desired current sectors from
of a fuzzy logic controller for DC-DC input voltage references only. In order to
converter. Since DC-DC converters exhibit validate the proposed modulation
more of non-linear characteristics, a non- techniques, simulation results are
linear controller, fuzzy logic controller will presented.
CASCADED H-BRIDGE MUTI-LEVEL ABSTRACT-In a hospital setting,
INVERTER FOR PHOTOVOLTAIC automation of patient care to some extent
SYSTEM will go a long way in reducing work load
on staff and in increased efficiency of
R.Deepa, Mrs.E.Jayashree. performance. A robot can be especially
Sree Sastha Institute of Engg. & Tech. used in the following areas like high risk
areas like radiology department, drug
(SSIET) deepa_sanju01@yahoo.co.in
delivery to patients in ICU and general
ekjayashree@gmail.com wards and many such areas like this. The
manipulator and the programming
Abstract-This paper presents a single-phase determines the function of the robot.
cascaded H-bridge inverter for photo voltaic Purpose of these robots is not to replace
(PV) application. It consists of single H- nurses but to help them so that they can
spend more time with patients.
bridge cell to produce five or more levels of
output. The cascaded H-bridge inverter
utilizes single PV cell to achieve nine level
output with reduced harmonics. This WAVELET BASED FAULT
inverter offers advantages such as DETECTION FOR WIND TURBINES
operation at lower switching frequency or
Dinesh Kumar.J, Karuppiah.S,
lower current ripple compared to standard Satish.S, Vishal. L
two-level inverter. Simulation and Amrita school of Engineering,
experimental results are presented for nine Coimbatore
levels of output. Special attention is dinesh.kumar0808@gmail.com
karuppiah05@gmail.com
dedicated to the latest and more relevant reachoutsathish@gmail.com
applications of these inverters such as vishal_mehta21@hotmail.com
laminators, conveyor belts and unified
power flow controllers. Abstract: The installed energy generation
capacity of wind turbines is increasing
dramatically on a global scale; this means
that reliability of wind turbines is of higher
importance. A part of this task is to
TELE-PRESENCE ROBOTIC
SURVEILLANCE FOR PATIENT CARE IN improve fault detection of the wind
HOSPITALS turbine. This paper uses a benchmark
model for simulation of fault detection.
D.Sudarvizhi, Anritha Ebenezer, Srividhya.P The benchmark model used deals with
the wind turbine on a system level
Avinashilingam Deemed University for containing sensors, actuators and system
Women, Coimbatore faults in the pitch system, drive train, and
generator and converter system. Wavelet
sudarvizhi.durai@gmail. com is used for fault detection in the wind
anritha.ebenezer@gmail.com turbine power generation system as
shreecool8@gmail.com described and the results of the faults are
comprehended in this paper.
