DAMPING OF SYNCHRONOUS GENERATOR BY STATIC REACTIVE POWER COMPENSATOR WITH DIGITAL CONTROLLER

A static reactive power (VAr) compensator (SVC), constructed by fixed capacitors (FC) snd thyristor controlled reactors (TCRs), is designed and implemented to improve the damping of the synchronous generator. A digital propotional-integral (PI) controller is synthesised by the Motorola M68HC11 single chip microprocessor board to modify the reactive power compensation of the SVC from adjusting the conduction angle of the thyristors. The SVC is placed at the generator bus terminal with the speed deviation (DELTA-omega) as the feedback signal for the PI controller. The pole assignment method is used to determine the gains of the PI controller. Results from digital simulation and the implementation test show that the SVC with the PI controller can greatly enhance the damping of the system oscillation caused by disturbances. Although the PI controller is designed at a special operation point, it can also provide a good damping effect at other operation conditions. The voltage profile of the generator is also improved by the SVC.