Design of Fractional-order Power System Stabilizer

Abstract

Power system stabilizers (PSS) are auxiliary controllers designed to nullify the adverse effect of the high gain, fast responding (low time constant) Automatic Voltage Regulator (AVR). The conventional way of PSS design is bounded for a particular operating condition of the system under consideration. But the power systems itself is highly complicated and complex. So the system complexity demands that the constructed PSS to be sufficiently robust. The conventionally designed PSS cannot overcome this problem. Therefore, several studies have been performed in a search to develop a more robust PSS to overcome the demerits of conventional PSS. In this paper new design approach using fractional calculus is proposed to design the PSS. This Fractional-order Power System stabilizer (FoPSS) is more robust and provides excellent performance over wide range of system operating conditions.The performance of the proposed FoPSS is evaluated through eigevalue analysis and non-linear time domain simulation on Single Machine Infinite Bus system (SMIB). Comparing the performance of the proposed FoPSS with Conventionally designed Power System Stabilizer (CPSS) it is observed that FoPSS ensures improved system stability.