zsc

A PAPER PRESENTATION

ONIMPEDANCE SOURCE CONVERTER BASED WIND ENERGY SYSTEMS

By

Althaf hussaisn Shaik(K L university)

Nadendla Srikanth(K L University)

THEME

• To improve the utilization of wind energy system using efficient generator and suitable converter.

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OBJECTIVES

The different generators used in wind energy system.

Why a PE converter needed in wind energy system.

How the z source converter different from other converters.

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WIND ENERGY CONVERSION SYSTEM

Fig: Block diagram

• Fixed speed wind turbines

• Partially Variable speed wind turbines

• Fully Variable speed wind turbines

ElectricalGenerator

Wind turbin

e

Power electronic interface

Gird

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VARIABLE SPEED WIND ENERGY CONVERSION SYSTEM

DFIG Transformer

Wind gear

external

box grid

partial-rating power converter

Fig: variable speed wind energy conversion system

G

DCAC

AC

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FULLY VARIABLE WIND ENERGY CONVERSION SYSTEM

AC-DC converter

DC-AC converter

DCAC

GridGearbox

Syn generatorDC-Link

Fig: Fully-variable system 5

WHY DFIG ?

• DFIG provides more operating range compared to other

• It provides -40% to +30% speed range.

• The power flows in both rotor and stator

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WHY A P.E CONVERTER IS NEEDED IN WIND ENERGY CONVERSION ?

• The wind flows may not be fully controlled and can cause variances in the frequency at which the power is generated.

• Power electronic devices are utilized in these systems to convert the generated ac voltages into HVDC.

• Through these devices, the power delivered by these

systems is cleaner and has a higher P.F .

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COMPARISON OF WIND ENERGY CONVERSION SYSTEMS

Sno: WEC Based on Generator

Grid integration

1 Fixed speed System

Induction generator

Direct

2Partially

variableSystem

DFIG VSC

3 Fully-variable system

Induction or synchronous VSC or ZSC

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WIND ENERGY CONVERSION SYSTEM

Fig: fully variable system

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BOOST CONVERTER + INVERTER

Fig: WEC system with boost converter and inverter 10

Z-SOURCE INVERTER

Fig: WEC system with Z-source converter 11

SINGLE PHASE ZSC

v

z s a s t

z s a s

Fig: single phase z-source converter 12

ACTIVE STATE

Fig: Active state 13

SHOOT THROUGH STATE

Fig: Shoot through state 14

SWITCHING SEQUENCE

S.no S1 S2

S3

S4

STATE

1 1 1 0 0 Zero

2 1 1 0 1 Shoot through

3 1 0 1 0 Active

4 1 1 1 0 Shoot through

5 0 0 1 1 Zero

6 0 1 1 1 Shoot through

7 0 1 1 0 Active

8 1 0 1 1 Shoot through 15

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Fig: MATLAB simulation 16

RESULTS

Fig: Active and shoot through states 17

ZSI SHOOT THROUGH STAGE

Fig: shoot through state 18

CONCLUSION:• By using both DFIG and ZSI in wind energy

systems we can get more efficiency and control over the active and reactive powers. The proposed system has high performance, minimal count, increased efficiency and reduced cost.

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Any queries ???

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Thank You

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