Multi-objective Coordinated Control Strategy for Real Bipolar VSC-MTDC Transmission System

Abstract

At present, voltage source converter based multi-terminal direct current (VSC-MTDC) technology has been widely applied. In the real bipolar VSC-MTDC converter station, the converters of positive and negative poles can be controlled independently. Firstly, in order to further increase the control flexibility of real bipolar VSC-MTDC system, the feasibility that stand-alone converters of positive and negative poles in the same converter station adopt different control strategies and the interaction effects are theoretically analyzed. Secondly, a multi-objective coordinated control strategy for real bipolar VSC-MTDC is proposed. In the same converter station, different control strategies are adopted in the stand-alone converters of positive and negative poles. In different system operation conditions, both the AC voltage stability and the active power consumption capacity of the bipolar DC system are improved by the corresponding coordinated pole-to-pole control method. Finally, the feasibility and validity of the proposed control strategy are verified in different operation conditions based on the real bipolar VSC-MTDC simulation system built on PSCAD/EMTDC.