A Novel Virtual Inertial Control Strategy for Double-Stage PV Generation

With an increasing penetration of PV generation in the electrical grid, the increasing replacement of large conventional synchronous generators by PV generation will result in short frequency regulation capability due to the reduced system inertia response. It is urgent for PV generation to take part in frequency regulation spontaneously. A virtual inertia control strategy based on the dynamic of high voltage DC capacitor for double-stage grid-connected PV generation is proposed in this paper. The influence of control parameters on virtual inertia control strategy is also analyzed. Finally, the theoretical analysis and control strategy are verified by simulation results. The results show that PV generation can provide more support power in the process of frequency sag when the integral coefficient of Boost converter voltage control loop is increase to slow down the dynamics response of DC voltage.