DESIGN OF HIGH EFFICIENCY PUSH-PULL CONVERTER FOR

PHOTOVOLTAIC APPLICATIONS

PRESENTED: ICCS-2015

BK BIRLA INSTITUTE OF ENGINEERING & TECHNOLOGY

Table of Content

1. Project goal and work organization.

2. Solar energy and India.

3. Introduction (System Overview).

4. Converter Topology.

5. Push-Pull Converter Design & Methodology.

6. Matlab Simulation model.

7. Hardware Layout.

8. Hardware design.

9. Test Results.

10. References.

Work Organization

1. The object of this project is to design a high efficient DC-DC converter using Push-Pull topology.

2. A compact Dc-Dc converter with grid connection possibility and less switching losses.

3. Design of 150W push-pull converter.

I. Center tap transformer Design

II. Output Filter design

III. Simulation using Matlab Simulink

IV. Device selection

V. Snubber circuit design

VI. Power PCB Design

VII. Control using dspic33fj128mc802

VIII. Zero voltage switching using controller

4. Heat sink and device mounting

5. Test and result Acquisition.

Solar Energy and India

• Above image gives the energy spectral densityin India.

• On a sunny day, the sun shines providesapproximately 1,000 watts per square meter ofthe surface energy of the planet.

Introduction – System Overview

In Push-Pull mode, the PWM outputs are alternately available on the PWMxH and PWMxL pins. For the firstperiod, PWMxH is active and, in the next period, PWMxL is active.

Push-Pull converter

Push-Pull converter have some advantages as comparison to others such as :• Multi slave output possible.• Due to symmetrical Push-Pull mechanism current is drawn from the line during both halves of

the switching cycle.

Push-Pull Converter Design & Methodology

Output Voltage

𝑂𝑢𝑡𝑝𝑢𝑡 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑣𝑜𝑙𝑡𝑎𝑔𝑒 𝑖𝑠 𝑔𝑖𝑣𝑒𝑛 𝑏𝑦 𝑉0 = 𝑉𝑖𝑛 − 1 ×𝑁𝑚

𝑁𝑝− 0.5

2𝑇𝑜𝑛

𝑇

Slave Outputs are given by

𝑉𝑠1 = 𝑉𝑖𝑛 − 1 ×𝑁𝑠1

𝑁𝑝− 1

2𝑇𝑜𝑛

𝑇

𝑉𝑠2 = 𝑉𝑖𝑛 − 1 ×𝑁𝑠1

𝑁𝑝− 1

2𝑇𝑜𝑛

𝑇

This converter is preferred in low input voltage applications because the voltage stress is twice the input voltage due to the tapped primary transformer.

Matlab Simulink model

𝐼𝑝𝑚 =𝑉𝑖𝑛 − 1 𝑇𝑜𝑛

𝐿𝑝𝑚

Output inductor design 𝐿𝑜 =0.05𝑉𝑜𝑇

𝐼𝑑𝑐

Output capacitor design 𝐶𝑜 =80×10−6

𝑉𝑟𝑑𝐼

Hardware Layout

Center Tap Push Pull Transformer Design

Converter Parameters

N - Channel Mosfet

Hardware Design of System

Test Results

Zero voltage switching with output DC bus voltage with out harmonics

Test Results at Low Power

• Harmonic less transformer secondary voltage• At full load system have approximately 1.6W conduction losses.

Test Results at full load

Rise time of the circuit=151ns

This converter have an efficiency of 90%.

CONCLUSION & FUTURE SCOPE

The converter is designed for 100 watt and efficiency is 90%.

Increasing environmental concerns should help the technology to becomefurther established as a marketable and economically viable product.

There is a vast resource available and PV technology is one of the mostfeasible renewable energy's for electricity generation

Future scope of this project is to provide controlled close loop with PID controller and to design full bridge sinusoidal inverter.

References

References from Books

1. Fundamental of Power Electronics(Erickson).

2. Switching Power Supply Design (Pressman).

References from research papers

1. [1]. H. L. Willis and W. G. Scott, Distributed Power Generation, Marcel Dekker, New York,2000.

2. [2]. N. Hatziargyriuo, H. Assano, R. Iravani and C. Marnay, “Microgrids,” IEEE Power andEnergy Magazine, vol. 5, no. 4, pp. 78-94, July-August 2007.

3. [3]. H. Jiayi, J. Chuanwn, X. Rong, “A review on distributed energy resources and microgrid”, Renewable & Sustainable Energy Reviews, vol. 12, pp. 2472-2483, 2008.

4. [4]. LipingGuo, John Y. Hung and R. M. Nelms, “Evaluation of DSP-Based PID and FuzzyControllers for DC–DC Converters”, IEEE Transactions on Industrial Electronics, Vol.56, No. 6, pp: 2237-2248, June 2009.

5. [5].Elton Pepa, “Adaptive Control of a Step-Up Full-Bridge DC-DC Converter for VariableLow Input Voltage Applications”, MS Thesis, Department of Electrical engineering,Virginia Polytechnic Institute and State University, February 2004.

Thank You