基于变载波频率的MMC损耗平衡控制策略  

MMC Loss Balance Control Strategy Based on Variable Carrier Frequency

作　　者：孙振威 邓富金 林金娇 孔祥平 SUN Zhen-wei;DENG Fu-jin;LIN Jin-jiao;KONG Xiang-ping(Southeast University,Nanjing 210096,China;不详)

机构地区：[1]东南大学,江苏南京210096 [2]国网江苏省电力有限公司电力科学研究院,江苏南京210036

出　　处：《电力电子技术》2024年第2期127-131,共5页Power Electronics

基　　金：江苏省科技项目(BE2022016);国家重点研发计划(2022YFE0196300)。

摘　　要：模块化多电平换流器(MMC)拓扑是中高压、大功率应用中最有吸引力的拓扑之一。MMC内部包含大量子模块(SM),每个SM都是一个潜在的故障点,SM发生故障被旁路后,将会导致故障桥臂剩余SM电容电压升高,损耗增大,引发MMC桥臂间损耗不均衡现象,危害MMC的可靠性。此处针对SM故障情况,提出一种基于变载波频率的MMC损耗平衡控制策略,根据故障桥臂和健康桥臂SM平均损耗的偏差实时调节故障桥臂SM的载波频率,以调节故障桥臂SM的开关损耗,从而实现故障桥臂和健康桥臂SM间的损耗平衡。与常规方法相比,所提方法不增加额外的建设成本,控制算法简单且不影响输出电能质量。仿真和实验结果表明,此处提出的MMC损耗平衡策略能够有效实现故障桥臂和健康桥臂的损耗平衡。The modular multilevel converter(MMC)topology is one of the most attractive topologies for medium-high voltage and high power applications.The MMC contains a large number of sub-modules(SM),and each SM is a poten-tial faulty point.After the SM fails and is bypassed,the voltage of the remaining SM capacitor in faulty bridge arm will rise,the loss will increase leading to unbalanced power loss among the MMC bridge arms,influencing the relia-bility of the MMC.Therefore,aiming at the SM faulty condition,a power loss balanced control strategy for MMC based on variable carrier frequency is proposed,the SM carrier frequency of the faulty bridge arm is adjusted according to the difference between the mean loss of the faulty bridge arm and the healthy bridge arm in real time to adjust the switching loss of the faulty bridge arm SM,so as to realize the loss balance between the faulty bridge arm SM and the healthy bridge arm SM.Compared with the conventional method,the proposed method does not increase the extra construction cost,and the control algorithm is simple and does not affect the output power quality.The simulation and experimental results show that the proposed loss balancing strategy for MMC can effectively realize the loss balance between faulty bridge arm and healthy bridge arms.

关 键 词：模块化多电平换流器 子模块 损耗平衡控制 变载波频率 

分 类 号：TM46[电气工程—电器]