Coordinated Power Control Strategy for the Multi-Terminal VSC-HVDC System

Abstract

In multi-terminal VSC-HVDC system, The most important prerequisite to ensure stable operation of the system is to maintain stability of the DC voltage, a coordinated power control strategy applies to multi-terminal VSC-HVDC system is proposed in this paper. The proposed control strategy can make the converter stations controlled by multiple fixed-point DC voltage distribute the power reasonably according to the capacity of station converters and the settings of operators, eliminating the DC voltage offset caused by change of load power, and also eliminating the adverse impact of DC line resistance on the accuracy of converters power distribution. Finally, the simulation is carried out on a three terminal physical prototype and also testified on a three terminal HVDC system in PSCAD/EMTDC, the effectiveness and validity of the proposed control strategy are verified.