MMC-HVDC功率运行区间的优化控制方法

摘要

提出了一种基于模块化多电平换流器高压直流输电(MMC-HVDC)系统的功率运行区间优化控制方法.建立了换流器内部环流的模型,揭示了子模块(SM)电容电压波动对换流器内部环流的影响机理;设计换流器二倍频电流补偿的相间环流抑制方法,降低了SM电容电压波动,进而扩大换流器的功率运行区间.基于Matlab/Simulink仿真平台搭建了双端MMC-HVDC仿真系统,仿真结果表明所提出的方法能够有效扩大其功率运行区间.%The control method to optimize the power margin of modular multilevel converter high voltage direct current transmission(MMC-HVDC) system is presented.By means of building the model of the internal circulating current of the converter,the theory that the impact on the internal circulating current of the converter from the fluctuation of sub-module(SM) capacitor voltage is revealed.Second harmonic current compensation in converter is designed to restrain circulating current among the phase,the fluctuation of SM capacitor is reduced,thus the power margin of converter is promoted.Based on the Matlab/Simulink double-ends,MMC-HVDC simulation system is established,the result indicates that the method promoted can effectively exceed the power margin of the MMC-HVDC.