Design of wide-area power system stabilizer considering packet drops

Abstract

Wide area monitoring systems (WAMS) serves as a platform to integrate the communication network with power system networks, along with its advantages WAMS adds some unavoidable constraints like delay and packet losses to the transmitted data which may affect the wide area power system stabilizer (WAPSS) performance. In WAMS, signals are sensed by phasor measurement units (PMUs) and transmitted to phasor data concentrators (PDCs) as packets with a time tag using Transmission Control Protocol (TCP) or User Datagram Protocol (UDP). Data is stored and aligned with respect to its time tag in PDC, when the packet drop occurs it results into absence of data at that particular instant and causes vacancies. In this paper, moving average method is proposed in order to estimate these vacancies. The estimated remote signal is used as input instead of signal with drops. The tuning of WAPSS is done by slap swarm algorithm (SSA) considering integral time absolute speed deviation (ISD) as objective function. Case study is under taken by considering two-area four-machine system under different test scenarios. The simulation results prove the satisfactory performance of proposed approach regarding inter-area oscillation damping.