摘要
MMC(Modular Multilevel Converter)具有高度对称的子模块级联结构,输出波形质量好,被广泛应用于高压直流输电等场合。MMC环流的存在会加剧桥臂损耗,使桥臂电流发生畸变,产生高次谐波分量,严重破坏电能质量。针对该问题,文中采用基于SOGI和直流积分器相互配合的多谐波滤波器提取环流的交流成分的方法,通过3个准PR(Proportional Resonant)控制器并联组成的新环流抑制器对环流进行抑制。在MATLAB/Simulink中搭建了11电平的MMC逆变仿真模型进行仿真实验,结果表明文中所提控制策略能够有效地完成对系统的控制。与传统环流抑制方法对比,文中所提方法的环流抑制效果更加明显,电容电压波动范围降低大约60%,证明了文中所提控制环流控制策略的正确性和有效性。
MMC is widely used in high-voltage DC transmission applications due to its highly symmetrical sub-module cascade structure and good output waveform quality.The presence of MMC circulating current will aggravate the bridge arm loss,distort the bridge arm current and generate high harmonic components,which will seriously damage the power quality.In view of this problem,this study adopts the method of extracting the AC component of the circulating current by a multi-harmonic filter based on the interplay of SOGI and DC integrator and suppressing the circulating current by a new circulating current suppressor composed of three quasi-PR controllers connected in parallel.An 11-level MMC inverter simulation model is established on MATLAB/Simulink platform,and the simulation results show that the proposed control strategy can effectively complete the control of the system.Compared with the traditional circulating current suppression method,the circulating current suppression effect of the proposed method is more obvious,and the capacitor voltage fluctuation range is reduced by about 60%,which verifies the correctness and effectiveness of the proposed control circulating current control strategy.
作者
韦圣辉
郝正航
陈卓
WEI Shenghui;HAO Zhenghang;CHEN Zhuo(The Electrical Engineering College,Guizhou University,Guiyang 550025,China)
出处
《电子科技》
2023年第7期16-23,共8页
Electronic Science and Technology
基金
第二批国家级新工科研究与实践项目(E-NYDQHGC20202227)。
