高电压技术2025，Vol.51Issue(2)：558-569,中插3-中插4,14.DOI:10.13336/j.1003-6520.hve.20241067
基于负电平利用的超大容量MMC分析与设计方法
Analysis and Design Method of Ultra-large-capacity MMC Based on Negative Voltage State Utilization
摘要
Abstract
The transmission of power from large-scale new energy base through long-distance DC transmission poses new challenges for increasing the capacity of modular multilevel converter(MMC).The utilization of negative voltage states(NVSs)by adding extra full-bridge submodules can extend the linear modulation range of MMCs and significantly en-hance their achievable capacity.First,an approximate model of the NVS utilization method is established,revealing the influence of the NVS utilization coefficient on the designable value of the MMC's AC side rated voltage,allowing for a simple and rapid estimation of the capacity enhancement extent.Furthermore,an accurate analytical model considering the influence of capacitor voltage ripple effects,the second-order harmonic circulating current control,and the NVS utili-zation coefficient is developed.Meanwhile,based on the accurate analytical model,a three-layer iterative search parameter design method for the NVS utilization approach is proposed,which can achieve optimal design of key MMC parameters for different capacity design goals.Based on a case study involving capacity enhancement of a 5 000 MW MMC,the cost of MMCs under NVS utilization is analyzed.The results indicate that the economic range for NVS utilization is between 5 000 MW and 7 250 MW,within which the cost of NVS utilization method is the lowest among various capacity en-hancement methods.Simulations were conducted to verify the correctness of the proposed analysis and design methods.关键词
大容量新能源基地/柔性直流输电/模块化多电平换流器/全桥子模块/负电平利用/容量提升Key words
large-capacity new energy base/voltage-source converter-based high voltage DC transmission/modular multilevel converter/full-bridge submodule/negative voltage states utilization/capacity enhancement引用本文复制引用
王云飞,赵晓斌,宋强,黄碧月,辛清明,寻斌斌..基于负电平利用的超大容量MMC分析与设计方法[J].高电压技术,2025,51(2):558-569,中插3-中插4,14.基金项目
国家重点研发计划(2023YFB2405900) （2023YFB2405900）
中国南方电网有限责任公司科技项目(ZBKJXM20232463).Project supported by National Key R&D Program of China(2023YFB2405900),Science and Technology Project of China Southern Power Grid Co.,Ltd.(ZBKJXM20232463). （ZBKJXM20232463）
