稳态负电平输出下的混合型MMC设计方法  

A Design Method of Hybrid Modular Multilevel Converter With Negative Output in Steady State

作　　者：林艺哲 林磊[1] 徐晨 LIN Yizhe;LIN Lei;XU Chen(State Key Laboratory of Advanced Electromagnetic Engineering and Technology（School of Electrical and Electronic Engineering,Huazhong University of Science and Technology）,Wuhan 430074,Hubei Province,Chin)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院)

出　　处：《中国电机工程学报》2018年第14期4202-4211,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51677077)~~

摘　　要：混合型模块化多电平换流器（modular multilevel converter,MMC）桥臂中含有半桥子模块和全桥子模块。利用全桥子模块的负电平输出能力,混合型MMC可具备直流故障处理能力,在稳态下也可实现电压调制比大于1的工况,进而可实现直流降压运行或交流提压运行。该文针对稳态下利用全桥子模块输出负电平的工况提出一种混合型MMC的设计方法。根据电压调制比大于1的需求和直流故障穿越能力的需求,明确混合型MMC桥臂中全桥子模块占比的设计原则。同时,对半桥子模块和全桥子模块电容电压的波动情况进行详细的分析,描述子模块电容电压波动情况,并总结出子模块电容参数的设计方法。最后,通过仿真对所述设计方法的可行性和正确性进行验证。The hybrid modular multilevel converter（MMC） has the ability to deal with DC short fault since full-bridge sub-module（FBSM） can produce negative output. In addition, the modulation index can be promoted over one with the negative output from FBSMs in steady state. With this ability, hybrid MMC can operate with low DC voltage or with boosted AC voltage under limited DC voltage. This paper proposed a design method of hybrid MMC on the situation that FBSMs generate negative output in steady state. In terms of high modulation index and DC fault riding through, the principle to design the proportion of FBSMs in hybrid MMC was proposed. Moreover, the physical process of capacitor voltage fluctuation in half-bridge sub-module（HBSM） and FBSM was analyzed in detail. The capacitor voltage fluctuation was demonstrated and the computing method of the sub-module capacitance was proposed. Simulations were implemented to verify the feasibility and validity of the proposed design method.

关 键 词：混合型模块化多电平换流器 负电平输出 全桥子模块占比 子模块电容 

分 类 号：TM46[电气工程—电器]