12429

Page 1 of 9

Journal for Studies in Management and Planning

Available at http://edupediapublications.org/journals/index.php/JSMaP/

ISSN: 2395-0463

Volume 04 Issue 03

March 2018

Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 181

High efficiency Single-Input Multiple-Output chopper circuit

VENNAM SRAVANTHI 1 ,Venkateswarareddy Golamari2,

M.Tech scholar, Department of EEE sai tirumala nvr engineering college a.p India.

Assistant professor, Department of EEE, sai tirumala nvr engineering college,a.p India.

Abstract:- The aim of this study is to develop a high

efficiency single-input multiple-output (SIMO) chopper

ciruit. The proposed converter can increase the

voltage of a low level voltage input power source to a

controllable high level voltage dc bus and mid-level

voltage output terminals. The high level voltage dc bus

can take as the main power for a high level voltage dc

load or for a dc–ac inverter. Moreover, mid-level voltage

output terminals can supply powers for individual mid- level voltage dc loads or for charging auxiliary power

sources (e.g., battery modules). In this study, a coupled- inductor based dc–dc converter utilizes only one power

switch with the corresponding device specifications are

adequately designed. As a result, the objectives of high- efficiency power conversion, high step up ratio, and

various output voltages with different levels can be

achieved.

Index Terms:-Coupled inductor, power conversion, single- input multiple-output (SIMO) converter voltage clamping.

I.INTRODUCTION

In order to protect the natural environment on the earth, the

development of clean energy without pollution has themajor

representative role in the last decade [1]–[3]. By dealing with

the issue of global warming, clean energies, such as fuel cell

(FC), photovoltaic, and wind energy, etc., have been rapidly

promoted. Due to the electric characteristics of clean energy,

the generated power is critically affected by the climate or

has slow transient responses, and the output voltage is easily

influenced by load variations [4]–[6]. Besides, other auxiliary

components, e.g., storage elements, control boards, etc., are

usually required to ensure the proper operation of clean

energy. For example, an FC-generation system is one of the

most efficient and effective solutions to the environmental

pollution problem [7]. In addition to the FC stack itself, some

other auxiliary components, such as the balance of plant

(BOP) including an electronic control board, an air

compressor, and a cooling fan, are required for the normal

work of an FC generation system [8], [9]. In other words, the

generated power of the FC stack also should satisfy the

power demand for the BOP. Thus, various voltage levels

should be required in the power converter of an FC

generation system. In general, various single-input single- output dc–dc converters with different voltage gains are

combined to satisfy the requirement of various voltage levels,

so that its sys-tem control is more complicated and the

corresponding cost is more expensive. The motivation of this

study is to design a single-input multiple-output (SIMO)

converter for increasing the conversion efficiency and

voltage gain, reducing the control complexity, and saving the

manufacturing cost.[10] presented a SIMO dc–dc converter

capable of generating buck, boost, and invertedoutputs

simultaneously. However, over three switches for one

output were required. This scheme is only suitable for the

low output voltage and power application, and its power

conversion is degenerated due to the operation of hard

switching.[11] proposed a new dc–dc multi-output boost

converter, which can share its total output between different

series of output voltages for low- and high-power

applications. Unfortunately, over two switches for one output

were required, and its control scheme was complicated.

Besides, the corresponding output power cannot supply for

individual loads independently. This study presents a newly

designed SIMO converter with a coupled inductor. The

proposed converter uses one power switch to achieve the

objectives of high-efficiency power con-version, high step-up

ratio, and different output voltage levels. In the proposed

SIMO converter, the techniques of soft switching and voltage

clamping are adopted to reduce the switching and

conduction losses via the utilization of a low-voltage-rated

Page 2 of 9

Journal for Studies in Management and Planning

Available at http://edupediapublications.org/journals/index.php/JSMaP/

ISSN: 2395-0463

Volume 04 Issue 03

March 2018

Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 182

power switch with a small RD S(on) . Because the slew rate of

the current change in the coupled inductor can be restricted

by the leakage inductor, the current transition time enables

the power switch to turn ON with the ZCS property easily,

and the effect of the leakage inductor can alleviate the losses

caused by the reverse-recovery current. Additionally, the

problems of the stray inductance energy and reverse- recovery currents within diodes in the conventional boost

converter also can be solved, so that the high-efficiency

power conversion can be achieved. The voltages of middle- voltage output terminals can be appropriately adjusted by

the design of auxiliary inductors; the output voltage of the

high-voltage dc bus can be stably controlled by a simple

proportional-integral (PI) control. This study is mainly

organized into five sections. Following the introduction, the

converter design and analyses are given in Section II. In

Section III, the design considerations of the proposed SIMO

converter are discussed in detail. Section IV provides

simulation results of proposed converter.

II. CONVERTER DESIGN AND ANALYSES

The system configuration of the proposed high-efficiency

SIMO converter topology to generate two different voltage

levels from a single-input power source is depicted in Fig. 1.

This SIMO converter contains five parts including a low- voltage-side circuit (LVSC), a clamped circuit, a middle- voltage circuit, an auxiliary circuit, and a high-voltage-side

circuit (HVSC). The major symbol representations are

summarized as follows. VFC (iFC ) and VO1 (iO1) denote the

voltages (currents) of the input power source and the output

load at the LVSC and the auxiliary circuit, respectively; VO2

and iO2 are the output voltage and cur-rent in the HVSC. CFC ,

N = N2/N1 (1)

k = Lmp/(Lkp + Lmp) = Lmp/LP (2)

Where N1 and N2 are the winding turns in the primary and

secondary sides of the coupled inductor Tr .

Fig. 1.System configuration of input multiple-output (SIMO)

converter.

Because the voltage gain is less sensitive to the coupling

coefficient and the clamped capacitor C1 is appropriately

selected to completely absorb the leakage inductor energy

[13], the coupling coefficient could be simply set at one (k =

1) to obtain Lm p = LP via (2). In this study, the following

assumptions are made to simplify the converter analyses: 1)

The main switch including its body diode is assumed to be an

ideal switching element; and 2) The conduction voltage drops

of the switch and diodes are

neglected.

CO1 , and CO2 are the filter capacitors at the LVSC, the auxiliary

circuit, and the HVSC, respectively; C1and C2are the clamped

and middle-voltage capacitors inthe clamped and middle- voltage circuits, respectively. LP and LSrepresent individual

inductors in the primary and secondarysides of the coupled

inductor Tr , respectively, where the primary side is

connected to the input power source; Laux is the auxiliary

circuit inductor. The main switch is expressed as S1 in the

LVSC; the equivalent load in the auxiliary circuit is

VFC

IMP

LAUX

C R V

C02 R02 V

represented as RO1and the output load is represented as RO2

in the HVSC.The corresponding equivalent circuit given in

Fig. 2 is used to define the voltage polarities and current

directions. The coupled inductor in Fig. 1 can be modelled as

CFC

01 01 01

an ideal transformer including the magnetizing inductor Lm

p and the leakage inductor Lk p in Fig. ʹ. The turn’s ratio N

and coupling coefficient k of this ideal transformer are

defined as

Fig.2.Equivalentcircuit

II.AOperation Modes

Page 3 of 9

Journal for Studies in Management and Planning

Available at http://edupediapublications.org/journals/index.php/JSMaP/

ISSN: 2395-0463

Volume 04 Issue 03

March 2018

Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 183

The characteristic waveforms are depicted in Fig. 3, and the

topological modes in one switching cycle are illustrated in

Fig. 4.

Mode 1 (t0 –t1 ) [Fig. 4(a)]: In this mode, the main switch

S1 was turned ON for a span, and the diode D4 turned OFF.

Because the polarity of the windings of the coupled inductor

Tr is positive, the diode D3 turns ON. The secondary current

iL s reverses and charges to the middle-voltage capacitor C2 .

When the auxiliary inductor Laux releases its stored energy

completely, and the diode D2 turns OFF, this mode ends.

Mode 2 (t1 –t2 ) [Fig. 4(b)]: At time t = t1 , the main switch

S1 is persistently turned ON. Because the primary inductor

LP is charged by the input power source, the magnetizing

current iLmp increases gradually in an approximately linear

way. At the same time, the secondary voltage vL s charges the

middle-voltage capacitor C2 through the diode D3 . Although

the voltage vL m p is equal to the input volt-age VFC both at

modes 1 and 2, the ascendant slope of the leakage current of

the coupled inductor (diL k p /dt) at modes 1 and 2 is

different due to the path of the auxiliary circuit. Because the

auxiliary inductor Laux releases its stored energy completely,

and the diode D2 turns OFF at the end of mode 1, it results in

the reduction ofdiL k p /dt at mode 2.

Mode 3 (t2 –t3 ) [Fig. 4(c)]: At time t = t2 , the main switch

S1 is turned OFF. When the leakage energy still released from

the secondary side of the coupled inductor, the diode D3

persistently conducts and releases the leakage energy to the

middle-voltage capacitor C2 . When the voltage across the

main switch vS 1 is higher than the voltage across the

clamped capacitor VC 1 , the diode D1 conducts to transmit

the energy of the primary-side leakage inductor Lk p into the

clamped capacitor C1 . At the same time, partial energy of the

primary-side leakage inductor Lk p is transmitted to the

auxiliary inductor Laux , and the diode D2 conducts. Thus,

the current iL aux passes through the diode D2 to supply the

power for the output load in the auxiliary circuit. When the

secondary side of the coupled inductor releases its leakage

energy completely, and the diode D3 turns OFF, this mode

ends.

Mode 4 (t3 –t4 ) [Fig. 4(d)]: At time t = t3 , the main switch

S1 is persistently turned OFF. When the leakage energy has

released from the primary side of the coupled inductor, the

secondary current iL S is induced in reverse from the energy

of the magnetizing inductor Lm p through the ideal

transformer, and flows through the diode D4 to the HVSC. At

the same time, partial energy of the primary-side leakage

inductor Lk p is still persistently transmitted to the auxiliary