Impact of large photovoltaic penetration on small signal stability

This paper investigates the impact of solar photovoltaic generation in small signal stability in a two area system at different penetration levels. The tested system also consists of the Flexible AC Transmission system (FACTS) device. This paper uses the Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC). The analysis can be categorized into three cases. The first case is performed without incorporating any FACTS device. The second case corresponds to the investigation with SVC and the third with TCSC. The study uses the linearized eigen value analysis to obtain the crucial information about the critical modes, oscillation frequency and system damping. The analysis is further enhanced through the time domain simulation results. The study has shown that the integration of PV has mostly the beneficial impact on small signal stability. Moreover, this analysis has also shown that at very high PV penetration which causes the displacement of a large synchronous generator, the combined use of PV and TCSC can overcome this problem of loss of damping and still enhance the small signal stability.