基于陷波器改进PIR的MMC环流抑制策略

MMC Circulation Suppression Strategy Based on Improved PIR with Naptrap

伴随高压直流输电技术的不断完善,换流器的传统高压直流输电系统已经步入成熟期。由于MMC换流器中存在环流,导致换流器产生额外的损耗,桥臂电流波形因此会产生畸变,因此,在控制系统中应该制定相应的环流抑制策略。基于此分析了MMC相间环流机理,得出环流的主要成分为二次谐波与四次谐波;在传统的基于PR控制器的环流抑制方法基础上,提出了基于陷波器的改进PIR控制器的环流抑制策略;通过在PSCAD/EMTDC仿真平台上的仿真实验,验证所提的改进环流抑制器的效果。

With the continuous improvement of HVDC transmission technology,the traditional HVDC transmission system of converter has stepped into the mature period.Because of the circulation in the MMC converter,the converter will produce extra loss and the bridge arm current waveform will be distorted.Therefore,the corresponding circulation suppression strategy should be formulated in the control system.In this paper,the mechanism of phase circulation in MMC is analyzed.The main components of the circulation are second and fourth harmonics.Based on the traditional circulation suppression method based on PR controller,an improved PIR controller based on notch notch is proposed.Through the simulation experiment on PSCAD/EMTDC simulation platform,the effect of the improved circulation suppressor proposed in this chapter is verified.