基于混合型MMC内部能量优化利用的改进型故障穿越控制策略  

Improved FRT control strategy based on optimal utilization of energy within hybrid MMC

作　　者：谢建峰 庄凯 刘承鑫 张岌淼 顾亦超 XIE Jianfeng;ZHUANG Kai;LIU Chengxin;ZHANG Jimiao;GU Yichao(School of Electronic and Electrical Engineering,Chongqing University of Science and Technology,Chongqing 401331,China;The Department of Electrical and Computer Engineering,Rowan University,Glassboro 08028,USA)

机构地区：[1]重庆科技大学电子与电气工程学院,重庆401331 [2]罗文大学电气与计算机工程系,美国葛拉斯堡罗08028

出　　处：《电力自动化设备》2025年第5期185-192,共8页Electric Power Automation Equipment

基　　金：重庆市教委科学技术研究项目(KJQN201901543)。

摘　　要：当混合型模块化多电平换流器(MMC)发生直流侧短路故障时,常规故障穿越(FRT)控制策略虽能通过全桥子模块(FBSM)消除故障电流,但交流侧功率和频率会由于缺乏主动支撑而快速跌落。因此,提出一种基于混合型MMC内部电容能量优化利用的改进型FRT控制策略。对利用电容能量主动支撑交流侧电网有功功率进行路径分析,设计了直流故障下有功功率的柔性补偿方案。建立实时监测电容能量状态的离散时域功率预测模型,结合故障下最近电平调制(NLM)动态电容参考电压计算,进一步提高了FRT控制中柔性补偿的深度。仿真结果表明,所提改进型FRT控制策略使交流侧有功功率跌落时间延长至上百毫秒,进而有效抑制了直流故障的威胁及其对交流侧电网产生的负面影响。When a hybrid modular multilevel converter(MMC)experiences a DC-side short circuit fault,the conventional fault ride-through(FRT)control strategy can eliminate fault current by full-bridge sub-modules(FBSMs),but the AC-side power and frequency will experience a rapid decline due to the lack of active support.Therefore,an improved FRT control strategy based on optimal utilization of internal capacitor energy of hybrid MMC is proposed.A path analysis is conducted to actively support the AC-side grid active power using capacitor energy.A flexible active power compensation scheme is designed for DC faults.A discrete time domain power prediction model that can monitor capacitor energy status in real-time is established.By integrating dynamic capacitor reference voltage calculation with the nearest level modulation(NLM)during faults,the depth of flexibility compensation in FRT control is further improved.The simulative results indicate that the proposed improved FRT control strategy extends the duration of AC-side active power drop to hundreds of milliseconds,effectively mitigating the threat of DC faults and their negative effects on the AC-side grid.

关 键 词：故障穿越控制 混合型模块化多电平换流器 最近电平调制 柔性补偿 功率预测模型 

分 类 号：TM721.1[电气工程—电力系统及自动化]