A Centralized Frequency Regulation Strategy of PV Power Plant Based Equal Adjustable Capacity Proportion Mode

A centralized frequency regulation strategy of PV plant based on equal adjustable capacity proportion mode is proposed in this paper. When the system frequency changes due to some disturbances, the requirement of adjust active power value is calculated according to the frequency changing, then original active power reference is added with this adjust value to obtain the final active power reference as to change the active power output of PV units to participate in system primary frequency regulation. On this basis, in order to allow all PV units in same PV plant to coordinate with each other, also to prevent some PV units from excessive regulation, a proportional regulation of power method (PROP) is implemented to allocate active power reference to each PV unit more reasonable, namely, each PV unit's output is according to equal adjustable capacity proportion. Finally, an actual PV plant model is established on DIgSILENT PowerFactory platform to verify the effectiveness of the proposed control strategy.