VSC-MTDC输电系统直流电压控制策略研究

Research on Voltage Control Strategy of VSC-MTDC Transmission System

摘要: 本文建立了PSCAD/EMTDC下基于电压源型换流器的多端直流(VSC-MTDC)输电系统模型。每个换流站采用基于IGBT三相桥型拓扑结构，设计了定有功功率控制器、定无功功率控制器和定直流电压控制器。分析了VSC中的电压偏差控制和直流电压–有功功率下降控制的工作原理，指出了电压偏差控制存在的问题，提出了一种综合直流电压控制策略。仿真结果表明综合电压控制方式响应迅速，功率潮流自动调整且超调量小，稳定性增强。
>A multi-terminal HVDC system (MTDC) based on voltage source converter (VSC) is built in PSCAD/ EMTDC in this paper. Each converter station has three-phase bridge topology with IGBT. Its control system is designed to realize the real power control, reactive power control and DC voltage control. The principles of voltage deviation control and voltage-power drop control in VSC are analyzed. Considering the problems of voltage deviation control, an improved DC voltage control strategy is put forward. Simulation results show that integrated voltage control has quick response, power flow self-regulation, small overshoot and enhanced stability.