Soft Switching Boost Converter With Mppt for Solar (1)2233

7/30/2019 Soft Switching Boost Converter With Mppt for Solar (1)2233

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SOFT SWITCHING BOOST CONVERTER

WITH MPPT FOR SOLAR HOMELIGHTING SYSTEM

D.Shankar , A.S.WerulkarAnd P.S.Kulkarni

Presented by:

D.Shankar

M.Tech,ELECTRICAL ENGG.DEPT. , VNIT

E-mail:[email protected]


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WHY SOLAR ENERGY?

Solar energy is the most readily available source of

energy.

It is free.

It is also the most important of the non-conventionalsources of energy because it is non-polluting.


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OUTLINE

Modeling of PV module

Maximum power point tracking

Soft-switching dc-dc converter

PV systems with MPPT Perturb and Observe (P&O) MPPT algorithm

Conclusions

References


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INTRODUCTION

A MPPT system has been developed, consisting of a softswitching BOOST-type dc/dc converter, irrespective of the

temperature and irradiation conditions and of the load electrical

characteristics.

It overcomes the problem of mismatch between the solar arraysand the given load.

The conventional boost converter decreases the efficiency

because of hard switching, which generates losses when the

switches are turned on/off.


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MODELING OF PV MODULE A PV module consists of a number of solar cells

connected in series and parallel to obtain the desiredvoltage and current output levels.

Each solar cell is basically a p-n diode.

The basic equation that describes the current output of

PV module of the single diode model is given by

1expc

S

P

s

s

sPphpAKT

IRN

IR

N

Vq

ININI


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SOLAR CELLS CHARACTERISTICS.

The solar cell has nonlinear VIand PVcharacteristics,

which depend on the irradiance, the operating

temperature and load condition of the cell.

The CurrentVoltage relationship & The Power - voltage

relationship curve of a solar PV module is given by


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WHAT IS A MAXIMUM POWER POINT

TRACKER? Maximum Power Point Tracking (MPPT):

Technique used in power electronics systems to obtain the maximum

possible energy from PV arrays. Its use is desired to compensate for the effect of temperature, variations

in solar radiation, and load condition in a PV system.

A DC-DC converter (step up), serves the purpose of transferring maximum

power from the PV module to the load and acts as an interface between the

load and the module.


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PV ARRAY CURRENT-VOLTAGE CURVES

& POWER-VOLTAGE CURVES

Mismatch between resistive load and PV Source; current

voltage curves & powervoltage curves


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SOFT-SWITCHING DC-DC CONVERTER

The dcdc converter for a PV system has to control the

variation of the maximum power point of the solar cell

output.

Force the voltage across the switching device to drop to

zero before turning it ONZero-Voltage Switching

(ZVS)

Force the current through the switching device to drop to

zero before turning it OFFZero-Current Switching

(ZCS)


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WHY SOFT-SWITCHING?

Reduce switching losses especially at high switchingfrequencies.

Increase the power density, since the size and weight of

the magnetic components is decreased by increasing theoperating frequency.

Reduce the Electromagnetic Interference (EMI).


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SOFT-SWITCHING BOOST CONVERTER

Values of resonant inductor and resonant capacitor are

calculated by

minmaxmin

22IiTDVTVDL Lfwor

oo

r

r

r

V

TDI

V

LI

L

TDC

2

minmin

22

2

min

2

22

min8.0404.0


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MPPT LIMITATION

The maximum power transfer occurs when the

source impedance equal to load impedance. i.e. The input impedance is given by

The converter output voltage & current is given

by

The relation between & is given by

in

in

in

I

VR

D

VV

S

O

1)1( DII

SO

LOAD

O

O

S

S

inRD

I

VD

I

VR

22

11

LOAD

in

R

RD 1

inR

loadR


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BASIC PERTURB AND OBSERVE

Reference voltage control.

Direct duty ratio control.

System performance is affected by:

Step Size

Perturbation Frequency MPPTf

REFVDor


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CONTD..

Implemented through a DC/DC converter

LOGIC

1. Change duty cycle

2. Observe consequences on power output

3. Decide direction of next change in duty cycle


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PERTURBAND OBSERVE MPPT ALGORITHM


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BOOST CONVERTER & PVMODULE

PARAMETERS

Maximum Power(Po,

max )74Wp(optional)

Switching

frequency( fs)

20 kHz

PV Module Voltage

(Vi)

15-17.5V

Output Voltage (Vo) 25V

Main Inductor( L) 280H

Resonant Inductor(

Lr)

150H

Input Filter Inductor(Lf)

50H

Output

Capacitor(Co)

1000F

Table I. Boost Converter

Parameters

Open circuit voltage(Voc) 22.42V

Short circuit current(Isc) 4.2A

Maximum voltage(Vmpp) 18.83V

Maximum current(Impp) 3.93A

Maximum power at

STC(Pmax)

74WP

Table II. PV Module

Parameters


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MATLAB/SIMULATION &RESULTS

MPPT CONTROLLER

ZVS BOOST CONVERTERSOLAR PV PANEL


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V-I & P-V CHARACTERISTICS UNDERDIFFERENT

RADIATION(MATLAB/SIMULATIONRESULTS)

1000W/m21000W/m2


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ZVS BOOST CONVERTER(MATLAB/SIMULATION)


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Fig..1 Represent Waveform of Main Inductor Current and gate pulse.

Fig.2. Voltage and current waveform across main switch.


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Fig.3.Voltage across resonant capacitor and resonant inductor current

Fig.4. Voltage across diode.


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MPPT P&O METHOD


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PV MODULEPOWER, VOLTAGE, ANDCURRENT(WITH

MPPT

With out MPPT

At 25oC

&1000W/m2


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PV MODULEPOWER, VOLTAGE, AND

CURRENT(WITHSTEPINCREASESINRADIATION)

Time(sec)


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PV MODULE POWER, AND DUTY CYCLE

VARIATION(STEPSIZED =0.005)


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PV MODULE POWER, AND DUTY CYCLE

VARIATION(WITHSTEPINCREASESINRADIATION)


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CONCLUSIONS

The P&O MPPT algorithm is a simple algorithm that

does not require previous knowledge of the PV generator

characteristics or the measurement of solar intensity and

cell temperature.

Direct duty ratio control offers better stability

characteristics and higher energy utilization efficiency at

a slower transient response and worse performance at

rapidly changing irradiance.

Noise has significant impact on the algorithmperformance, especially with low step sizes where the

system response to noise is comparable to that of MPPT

perturbations.

REFERENCES


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REFERENCES

[1] R. Gules, J. De Pellegrin Pacheco, H. L. Hey, and J. Rnhoff, A

maximum power point tracking system with parallel connection for PV

stand-alone applications,IEEE Trans. Ind. Electron., vol. 55, no. 7, pp.

26742683, Jul. 2008.

[2] F. Liu, S. Duan, F. Liu, and Y. Kang, A variable step size INC

MPPT method for PV system,IEEE Trans. Ind. Electron., vol. 55, no. 7,

pp. 26222628, Jul. 2008.

[3] Sang-Hoon Park, Gil-Ro Cha, Yong-Chae Jung, and Chung-Yuen

Won, Senior Member, IEEE, Design and Application for PV GenerationSystem Using a Soft-Switching Boost Converter With SARC, IEEE

Transactions On Industrial Electronics, Vol. 57, No. 2, February 2010.

[4] Eftichios Koutroulis, Kostas Kalaitzakis, Member, IEEE, and

Nicholas C. Voulgaris Development of a Microcontroller-Based

Photovoltaic Maximum Power Point Tracking Control System., IEEE

TRANSACTIONS ON POWER ELECTRONICS, VOL. 16, NO. 1,

JANUARY 2001.

[5] Rahul S. Sable, A. S. Werulkar and P. S. Kulkarni , "Microcontroller

Based Soft Switching Buck Converter for Solar Home Lighting System.,

National conference on (ETREEE-201 ) pp.(167-173), February 25-

26,2012.


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Thank you

D.Shankar

E-mail:[email protected]

Documents

Soft Switching Boost Converter With Mppt for Solar (1)2233