Coordinated control strategy of multi-type power coupling system participating in primary frequency regulation of AC-DC hybrid power grid

Abstract

Wind power, photovoltaic (PV) power, thermal power and hydropower are connected to AC-DC power grid through the same power coupling point, which is common in North China. Such physical properties make it possible for multiple types of power sources to form a coupling system and behave as a large integrated power supply. How the coupling system participate in the primary frequency regulation (PFR) is a problem worthy of investigation. However, there is a lack of research in this field by now. In this paper, a coordinated control strategy of coupling system participating in PFR is proposed, that is, each power source separately measures the frequency and carries out PFR; the central controller of the coupling system is responsible for receiving related information of each power source, calculating and issuing the key parameters for each power source, such as the frequency control gain. A test system is established based on the actual regional power grid in Liaoning province, China. The simulation results under typical operating conditions verify the effectiveness of the proposed control strategy, which can realize the coordination of multiple power sources on the basis of ensuring the overall frequency regulation rapidity of the coupling system.