Reactive Power Control of an Alternator with Static Excitation System Connected to a Network

Dr Dhiya Ali Al-Nimma,Dr Majid Salim Matti

doi:10.33899/rengj.2010.28459

Abstract

In recent years, the scale of power systems has been expanding, and with that expansion smooth power operation is becoming increasingly important. One of the solutions is to realize a practical high speed, highly reliable exciter system that is suitable for stable operation of a power system. In this work, a model of a static excitation system of an alternator connected to a network via a transformer have been built using MATLAB-SIMULINK PSB. The parameters of the machine has been obtained from Mosul dam power station taking into account saturation effects. A PI controller is used to control the output reactive power of the synchronous generator for both pure DC excitation and static excitation systems. A method based on step response has been proposed and verified for tuning the parameters of the controller. In order to validate the simulated results of the system with AVR, the results have been compared with practical results of Mosul dam and a good agreement has been realized. However, in large generating units, undesirable oscillations in the active power and speed result as a side effect of the AVR control or due to outside disturbances. KEY WORDS: Static Excitation, Reactive Power Control.

Highlights

For many years the exciters used in alternators were DC generators driven by either the steam turbine on the same shaft of the generator or by an induction motor
A method for tuning the parameters of the controller has been proposed which depends on the step response of the system
The relation between field voltage and output reactive power can be approximated by first order transfer function for a certain range of field voltage

Summary

Introduction

For many years the exciters used in alternators were DC generators driven by either the steam turbine on the same shaft of the generator or by an induction motor. Its responsibility is to control current such that, building generator voltage at starting, regulating voltage and output reactive power after connecting the unit to a network.

Results

Conclusion