配电网故障状态下柔性多状态开关故障电流抑制策略  

Suppression Strategy for Fault Current of Flexible Multi-state Switch in Distribution Network Fault State

作　　者：马文忠[1] 吕清琛 张彦 张奎同 韩嘉 李沐书 MA Wenzhong;LV Qingchen;ZHANG Yan;ZHANG Kuitong;HAN Jia;LI Mushu(Institute of New Energy,China University of Petroleum(East China),Qingdao 266580,Shandong Province,China;Shandong Energy Group Co.,Ltd.,Jining 273500,Shandong Province,China)

机构地区：[1]中国石油大学(华东)新能源学院,山东省青岛市266580 [2]山东能源集团,山东省济宁市273500

出　　处：《电网技术》2021年第11期4251-4258,共8页Power System Technology

基　　金：国家自然科学基金项目(51777216);山东省自然科学基金项目(ZR2018MEE040,ZR2019MEE094)。

摘　　要：为抑制配电网交流故障持续期间柔性多状态开关(flexible multi-state switch,FMSS)注入短路点的故障电流,首先采用基于解耦双同步参考坐标系的瞬时对称分量分解方法对配电网不对称故障期间FMSS故障侧端口出现的负序、零序电流进行抑制。进一步推导出配电网三相短路接地故障时FMSS在不同运行工况下的系统向量图,利用对称分量法建立含FMSS配电网故障时的复合序网,分析配电网在对称性故障、不对称性故障时的故障电流大小,提出了一种带电压死区的无功下垂控制策略,实现故障状态下对FMSS注入短路点故障电流的有效抑制,同时根据配电网母线电压幅值变化相应地修正无功功率外环控制器指令值,利用FMSS对配电网提供无功支撑,改善馈线电压质量。采用MATLAB/SIMULINK搭建三端FMSS模型进行仿真分析,验证了所提方法的有效性与正确性。The fault current may be injected into the short-circuit point by the Flexible Multi-State Switch(FMSS) during the AC faults of the distribution network. In order to suppress this, this paper firstly uses the instantaneous symmetrical component decomposition method based on the decoupled dual synchronous reference frame to analyze the distribution network during an asymmetric fault, and the negative sequence and zero sequence currents appearing on the FMSS fault side port are suppressed. Secondly, the system vector diagrams of the FMSS are derived under different operating conditions when the three-phase short-circuit ground fault occurs in the distribution network. The symmetrical component method is used to establish a composite sequence network with the FMSS distribution network faults, the fault current of distribution network in symmetrical fault and asymmetric fault is analyzed, and a reactive power droop control strategy with voltage dead zone is proposed to effectively suppress the fault current injected into the short-circuit point of the FMSS under the fault state. At the same time, the controller modifies the reactive power outer loop control command value according to the change of bus voltage amplitude of distribution network, uses FMSS to provide reactive power support to the distribution network, and improve the quality of the feeder voltage. The MATLAB/SIMULINK is used to build a three-terminal FMSS model for simulation analysis, which verifies the effectiveness and correctness of the proposed method.

关 键 词：柔性多状态开关 模块化多电平换流器 下垂控制 无功补偿 故障电流抑制 

分 类 号：TM721[电气工程—电力系统及自动化]