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A TECHNICAL SEMINAR ON

BUCK CONVERTER FED BY PV ARRAY

PRESENTED BY Monika Rout

CONTENTS

INTRODUCTIONPV SYSTEM APPLICATIONS OF PV SYSTEMCHARGE CONTROLLERBUCK CONVERTERMAXIMUM POWER POINT TRACKINGADVANTAGESCONCLUSION

INSTITUTE OF TECHNICAL EDUCATION & RESEARCH,SOA University DEPT. of EICE

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INTRODUCTION

For environmental concern and increase in peak power

demand, PV solar cells has become an alternative energy

source for green and clean power generation.

With the growing demand for renewable sources of energy, the

manufacturing of solar cells and pv array has advanced in

recent years.

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PV SYSTEM4

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CONVERTERLOAD

+

-

Vmodule

moduleIPV MODULE

+

-

ILOAD

V load

Fig.1. Block diagram of the PV system [1]

Fig.2.Simplified equivalent circuit diagram of pv cell[3]

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PV SYSTEM(contd..) The PV cell output voltage is a function of the photocurrent

which is mainly determined by load current depending on the

solar radiation level during the operation.

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0

0

ln ph CCc S C

I I IKTV R I

e I

…………(1)

APPLICATIONS

– Agriculture– Industry, Telecommunications & Public Services– Internal space station– Health– Residential

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EUROPE

ASIA,JAPAN

NORTH AMERICA

INDIA,CHINA

SOUTH AMERICA

REST

30%15%

25%

7%

20%

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Fig.3.Status of the PV technology worldwide.[6]

3%

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CHARGE CONTROLLER

Charge controller regulates the charging and discharging of a

battery.

Such controllers are mainly used where loads are

unpredictable.

The batteries are optimized or undersized to minimize the

initial cost.

SHUNT TYPE CHARGE CONTROLLER10

Pv array

Charge controller

Blocking diode

battery+

_ load

S1

S2

Fig.4 circuit diagram for shunt charge controller[2]

SERIES TYPE CHARGE CONTROLLER11

Pv array

Charge controller

battery+

_ load

S1S2

Fig.5 circuit diagram for series charge controller[2]

DC TO DC CONVERTER TYPE CHARGE CONTROLLER

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Pv array Dc to dc converterload

battery

Fig.6 circuit diagram for dc to dc charge controller[2]

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MPPT CHARGE CONTROLLER

MPPT stands for maximum power point tracking

All types of solar installations will be benefited by using

MPPT technology.

To charge battery in more efficient manner, the pv array is

operated at a point where the pv output power is maximum.

To extract maximum power from pv array, a dc to dc converter

is used between the pv array and the battery

THE BUCK CONVERTER

o The buck is a non-isolated power stage topology, sometimes

called a step down power stage.

o These converters produce a lower average output voltage than

the DC input voltage.

o It consists of a DC input voltage source , inductor 𝑉𝑠 L,

controlled switch (BJT), diode D, filter capacitor C, and load

resistance R.

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Fig.7 circuit diagram for buck converter[5]

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Fig.8 waveform diagram for buck converter[5]

MAXIMUM POWER POINT TRACKING

Photovoltaic system displays an inherently nonlinear current

voltage (I-V) relationship .

When a solar pv module is used in a system, its operating

point is decided by the load to which it is connected.

To ensure the operation of pv modules for maximum power

transfer, method is called MPPT.

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Fig.7. Current/power Vs Voltage plot with MPPT [2]

ADVANTAGES

• No fuel requirement

• National economic benefits

• Easy to maintain

• Long life

• Environment friendly

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CONCLUSION

• A dc-dc buck converter is introduced between PV system and load to meet the dynamic energy requirement of the load in an efficient way. It is observed that, the buck converter largely increases the system efficiency by using MPPT technique.

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REFERENCE[1] S. Rahmam, M. A. Khallat, and B. H. Chowdhury, “A discussion on

thediversity in the applications of photovoltaic system,” IEEE Trans.,Energy Conversion, vol. 3, pp. 738–746, Dec. 1988.

[2]Chetan Singh Solanki,”Solar Photovoltaics,fundamentals,technologies and applications”, second edition, PHI LEARNING Private Limited,2012.

[3]B.Chitti Babu, R.Vigneshwaran, Sudarshan Karthik, Nayan Ku. Dalei,Rabi Narayan Das, “A Novel Technique for Maximum Power Point Tracking of PV Energy Conversion System”, Proc. of International Conf. on Computer Applications in Electrical Engineering, IIT Roorkee. pp.276-279,CERA 2010.

[4] S.Sukhatme,J.nayak “SOLAR ENERGY : PRINCIPLES OF THERMAL COLLECTION AND STORAGE”, Third edition,Tata McGraw-Hill, 2008.

[5]Dr. P.S Bimbhra: “Power electronics”, KHANNA PUBLISHERS, New Delhi,2010.

[6] G. Foley: “Photovoltaic Applications in Rural Areas of the Developing World”. World Bank, 2012.

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