Mitigation of subsynchronous resonance by SVC using PMU-acquired remote generator speed

Abstract

Subsynchronous resonance (SSR) is a potential problem in power systems having series compensated transmission lines. Flexible AC transmission systems (FACTS) controllers are widely applied to mitigate subsynchronous oscillations (SSO). With the advent of wide area measurement (WAM) technology, it is possible to measure the states of a large interconnected power system with synchronized phasor measurement units (PMU). In this paper the concept of using remote signals acquired through PMU has been proposed to damp SSR. An auxiliary subsynchronous damping controller (SSDC) for a static VAr compensator (SVC) using the remote generator speed as the stabilizing signal has been designed to damp subsynchronous oscillations. The IEEE first benchmark model is used to show the effectiveness of the controller. Extensive simulation results in EMTDC/PSCAD show that an SVC already installed in a transmission system with the primary objective of improving power transfer capability can also damp SSR with the auxiliary controller using remote generator speed. Finally, the effect of signal transmission delay is discussed