A Decentralized Frequency Regulation Strategy of PV Power Plant Based on Droop Control

In order to make full use of the active function of the photovoltaic (PV) power unit itself, a decentralized frequency regulation strategy for PV plant is proposed based on droop control idea in this paper. The active power regulation value, as an additional active power reference, is obtained according to the frequency regulation coefficient of PV unit; then the active power output of the PV unit is quickly regulated to the reference value, so that the frequency recovery of power system is restored. Since each PV unit in the power plant can achieve frequency regulation directly through the change of terminal frequency value, the response time will be faster than other control modes. Finally, a PV power plant which adopts the decentralized frequency regulation system is modelled on the DIgSILENT PowerFactory platform, and the control effect of the decentralized frequency regulation is verified by simulation results under different disturbances.