Evaluation of Methods for Improving and Testing Power System Stabilizers in Reciprocating Engines

Abstract

The small-signal stability of a power system is enhanced by damping system oscillations by power system stabiliser (PSS). In synchronous generators driven by reciprocating engines there are torque variations which in turn disturb the PSS operation. This thesis investigated the current methods used to design PSS for reciprocating engines and also the use of filters to reduce the engine torque uctuation. The use of torque change for testing PSS performance is also investigated. This is done by modelling a linearised single machine infinite bus (SMIB) along with PSS2B in Matlab as well as in Simpow software. The time and frequency domain analysis were used to evaluate the performance of the system with and without the PSS and notch filter. It is found that the proper tuning of PSS2B can improve the overall damping and stability of the system. The appropriate notch filter implementation at the frequency where the torque noise occur help to greatly attenuate the torque noise from the engine without affecting the PSS operation and overall stability. This also study shows that the deliberate torque change can be used for evaluation of PSS performance at local oscillation modes.