SIDDHARTH INSTITUTE OF ENGINEERING&TECHNOLOGY

A PAPER PRESENTATION

A STATCOM –CONTROL SCHEME FOR GRID CONNECTED WIND ENERGY SYSTEM FOR POWER QUALITY IMPROVEMENT

ON

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING k.Venu gopal

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ASTATCOM-CONTROL SCHEMEFORGRID CONNECTED WIND ENERGY SYSTEMFORPOWER QUALITY IMPROVEMENT

INTRODUCTION In integration of power generation system with grid we will

experience the power quality problems. Power electronic based FACTS

devices like STATCOM can be effectively utilized to improve the quality of power supplied to the customers The increasing use of power electronic based loads (adjustable speed drives, switch mode power supplies, etc) to improve system efficiency and Controllability is increasing concern for harmonic distortion levels in end use facilities and on overall power system.

OBJECTIVE OF THE TOPIC The grid connected wind energy generation system for power quality improvement by using STATCOM has the following objectives. To maintains power factor as unity at the source

end. To meet the reactive power to wind generator

and non-linear load. To provides hysteresis current controller for STATCOM to achieve fast dynamic response.

POWER QUALITY ISSUES

Voltage variation

Harmonics

Self Excitation of Wind Turbine Generating System

Wind turbine location in power system.

WIND ENERGY Wind is abundant almost in any part of the

world. Its existence in nature caused by uneven heating on the

surface of the earth as well as the earth’s rotation means that the wind resources will always be available.

WIND ENERGY GENERATING SYSTEM

Load

kinetic Energy

Mechanical Energy

Electrical Energy

STATCOM

A STATCOM is a voltage-source converter. Voltage compensation across the ac transmission Line. Increased line stability during transients. Commonly used for dynamic power factor correction. Elimination (or at least a major reduction) of voltage

fluctuations at the plant input.

STATCOM operation in a power system

Voltage compensation of ac transmission lines using a STATCOM

Grid Connected System for Power Quality Improvement

Source voltage and Current waveforms of test system without Wind farm and STATCOM

Source voltage and Current waveforms without STATCOM

Source voltage and current waveforms with STATCOM

The control scheme approach is based on injecting the cur- rents into the grid using “bang-bang controller.” The controller uses a hysteresis current controlled technique. Using such tech- nique, the controller keeps the control system variable between boundaries of hysteresis area and gives correct switching signals for STATCOM operation. The control system scheme for generating the switching signals to the STATCOM

CONTROL SCHEME:

Bang-Bang current controller is implemented in the current controlscheme.

Thereferencecurrentisgenerated and actualcurrentaredetectedbycurrentsensorsandaresubtracted for obtaining a current error for a hysteresis based bang-bang controller. Thus the ON/OFF switching signals for IGBT of STATCOM are derived from hysteresis controller

BANG BANG CONTROLLER

CONCLUSION

• The power quality issues and its consequences are presented.

• STATCOM has a capability to cancel out the harmonic parts of the load current.

• STATCOM maintains the source voltage and current in-phase and support the reactive power demand for the wind generator and load at PCC.

• Thus the proposed scheme fulfills the power quality norms as per the IEC standard 61400-21.

APPLICATIONS

Power system voltage control applications.

Large electric arc furnace installations.

Reactive power compensation applications.

Railway or underground systems with huge load variations.

FUTURE SCOPE

STATCOM can be replaced with UPQC for better power control.

Replacing the induction generator with doubly fed induction generator is preferred for better results.

In future the off-shore wind turbines will be implemented due to its advantages of producing high power.

SVC MaxSine STATCOM Solution for future.

ANY

QUERIES