Frequency Regulation For Double-stage Grid-connected PV Generation

With the rapid development of PV generation, the synchronous generator space with rotational inertia has been crowded out. At the same time the reserve capacity of primary frequency regulation is decreased and the disturbance rejection ability is weakened. There is an urgent need to study PV generation actively participate in frequency regulation of power grid. Taking the double-stage PV generation for an example and referring to the active-frequency static characteristic of synchronous generator (SG), this paper modifies the control strategies of Boost converter and grid-side inverter, respectively. The active power-frequency droop control strategy is adopted in double-stage PV generation and the active participation of PV generation in power grid frequency regulation is realized. At the same time, the virtual inertial control strategy of PV generation is also proposed, the influence of different control parameters on the virtual inertial control are analyzed. The effectiveness of the control strategies are verified by the simulation results in time domain.