【作者】 王帅； 戴珂； 方武平； 徐晨；

【Author】 Wang Shuai;Dai Ke;Fang Wuping;Xu Chen;State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology;

【机构】 华中科技大学强电磁工程与新技术国家重点实验室；

【摘要】 配电网中重型感性不平衡负荷启动时会导致公共连接点PCC电压跌落和不平衡,这将影响配电网和其它用电设备的安全稳定运行。本文首先分析了MMC-DSTATCOM(Modular Multilevel Converter based Distribution Static Synchronous Compensator)的工作原理并建立了数学模型。采用平均电容电压控制、桥臂电容电压均衡控制和子模块电容电压均衡控制实现直流电容电压平衡。为解决PCC电压跌落和不平衡问题,若基于PCC电压来提取补偿指令,可采用正、负序分离两套控制内环实现;若基于检测负载电流提取补偿指令,可采用PI加重复控制。最后进行了Matlab/Simulink仿真,搭建了一台三相十二模块的MMC-DSTATCOM实验样机,仿真和实验结果验证了MMC-DSTATCOM可以实现PCC电压支撑,并能有效抑制PCC电压不平衡。为解决PCC电压跌落和不平衡问题,若基于PCC电压来提取补偿指令,可采用正、负序分离两套控制内环实现;若基于检测负载电流提取补偿指令,可采用PI加重复控制。最后进行了Matlab/Simulink仿真,搭建了一台三相十二模块的MMC-DSTATCOM实验样机,仿真和实验结果验证了MMC-DSTATCOM可以实现PCC电压支撑,并能有效抑制PCC电压不平衡。更多还原

【Abstract】 The start of unbalanced heavy-duty reactive load will lead to voltage drop and imbalance of point of common coupling(PCC),which will affect the safe and stable operation of distribution network and other electrical equipment. This paper first analyzes the operation principle of modular multilevel converter based distribution static synchronous compensator(MMC-DSTATCOM)and a mathematical model is established. Using hierarchical control to realize capacitor voltage balance, which include averaging control, arm balancing control and individual balancing control. To solve the problem of the PCC voltage drop and imbalance, basing on PCC voltage to obtain compensation command, two sets of inner loop controller which include positive and negative sequence can be used; basing on load current, controller combining proportional integral(PI)and repetitive control can realize zero steady-state error tracing control. The result of Matlab/Simulink and experiment of three-phase twelve sub-modules prototype verify that MMC-DSTATCOM can support PCC voltage and effectively suppress PCC voltage imbalance.更多还原