System damping improvement using adaptive power system stabilizer

Because of the complexity of the network evolved from the interconnected large transmission systems and heavy generations, as well as the versatility of the customer loads, the use of the power system stabilizers has become common by the utilities today. To investigate the damping effects of a power system stabilizer, this paper studied an adaptive PSS by simulations and compared its damping effect with a conventional PSS in both time domain and frequency domain. It is clear that although both conventional PSS and adaptive PSS achieve the improvement to the system damping at both area and local modes, the studied adaptive PSS shows more effective damping than the conventional PSS. This is especially clear from the frequency analysis results. A flatter magnitude of Pe/Vr and a wider phase angle margin have been achieved from the adaptive PSS.