A Comparative Analysis of Transient Performance between PWM-based and Model-predictive-control-based Virtual Synchronous Generators

Distributed generators (DGs) based on Virtual Synchronous Generator (VSG) control can suppress the deviation in frequency at the expense of producing power oscillation. It was suggested that a damping term produced from state feedback control could be included in the VSG scheme to solve this issue. This method has been recently adopted for the VSG control using different techniques such as the pulse width modulation (PWM) and the Finite-Control-Set-Model-Predictive-Control (FCS-MPC) schemes. In this paper, the differences in the transient response of the VSG brought by these two methods are studied. Small signal models for both control methods are derived for comparing the power and frequency dynamic response during a small loading transition. The results verified by simulation in PSCAD/EMTDC have shown that the FCS-MPC-based VSG control's suppressing ability against the maximal frequency deviation is superior to its PWM counterpart. (DC/AC converter, Distributed power generations, Power system dynamics, Predictive control, Virtual synchronous generator).