A New Trend in Control of Renewable Power Systems Based on Virtual Synchronous Generator

Abstract

Today’s power systems have a high-level penetration of renewable energy sources (RESs). Therefore, the modern power systems become more susceptible to the system insecurity than conventional power systems due to lack of system inertia that results from replacing the conventional generators with RESs and frequency fluctuations that result from the intermittent nature of the RESs. Hence, this chapter presents a new strategy of frequency control including virtual inertia control based on virtual synchronous generator (VSG), which emulates the behavior of conventional synchronous generator in large power systems, thus adding some inertia to the system control loop virtually and accordingly stabilizing the system frequency during high penetration of RESs. Moreover, this chapter proposes an efficient coordination scheme of frequency control loops including the proposed virtual inertia control system-based VSG and digital over/underfrequency protection for maintaining the dynamic security of the renewable power systems because of the high integration level of the RESs. System modeling and simulation results are carried out using MATLAB/Simulink® software. Results approved that the proposed coordination scheme can effectively regulate the system frequency and guarantee robust performance to preserve the dynamic security of renewable power systems with high penetration of RESs for different contingencies.