Abstract:

Control strategy of voltage source converter (VSC) based multi-terminal HVDC transmission system is investigated in this paper. DC voltage feed-forward compensation and controller configuration of double closed loop based on linearized feedback of input and output are applied in controller design of the converter. This approach can realize decoupled control of active and reactive power. Meanwhile, it can improve the voltage and current waveforms at AC side of the converter. Multi-point DC voltage control strategy is proposed for stability control of the multi-terminal HVDC system, which is able to improve power balance ability of the multi-terminal DC(MTDC) system and enhance reliability and economy of system operation. Simulation is performed on a VSC-MTDC system with five terminals and the results show that the proposed control strategy with good dynamic characteristics is suitable for integration of distributed generation system and power system.