Coordinated control strategy between large-scale photovoltaic power stations and VSC-HVDC without communication

摘要

This paper proposes a novel coordinated control strategy between PV stations and VSC-HVDC without communication to well respond the frequency variation and fault ride-through of AC main grid, where the VSC-HVDC is assumed to deliver the PV power to the loads in the field without the large synchronous generators. In specific, the receiving end converter (REC) of VSC-HVDC will switch its control mode accordingly upon detecting the frequency and voltage variations, then the sending end converter (SEC) of VSC-HVDC will regulate its output voltage along with the DC voltage variation. And consequently, PV stations will adjust their output power reference in response to the AC voltage variation of VSC-HVDC SEC. Doing so, the active power balance between the PV stations and HVDC is achieved and the DC transmission voltage can be restored to the steady state value. As a result, the proposed method can save the communication investment and reduce the dc capacitance of VSC-HVDC. The theoretical findings were verified through both Matlab simulation and an experimental prototype.