A Review of Control Strategies for Inertia Support in VSC-HVDC System

The last few decades have seen the growing penetration of renewable energy sources (RES) to the power system, which mainly connect to the main grid via VSC-HVDC transmission link. With an increasing number of conventional synchronous generators (SGs) replaced by RES, power system inertia has reduced significantly, and the system response to frequency disturbance is worsened. This paper presents a review of control strategies for VSC-HVDC system to improve inertial response, most of which enable a VSC station to emulate the dynamics of an SG. Based on the potential of VSC-HVDC to participate in inertia support, RES is further considered to provide inertial response with the coordination of VSC-HVDC. The characteristics of some particular strategies are discussed and concluded, offering some suggestions for future work.