正负双序独立控制策略下的逆变型分布式电源不对称故障电流分析  

Analysis on asymmetric fault current characteristics of inverter interfaced distributed generator under positive-sequence and negative-sequence current respective control strategy

作　　者：常仲学 杨忠礼 宋国兵[1] 黄炜[1] 库永恒 苏高峰 王新铭 

机构地区：[1]西安交通大学电气工程学院,陕西西安710049 [2]国网河南新乡供电公司,河南新乡453002

出　　处：《电力自动化设备》2018年第1期44-51,共8页Electric Power Automation Equipment

基　　金：国家重点基础研究发展计划(973计划)项目(2012-CB215105);广东省科技计划项目(2015B010128006)~~

摘　　要：为揭示电网不对称故障下逆变型分布式电源的故障特征及机理,基于功率平衡和特性受控的思想,推导了基于正负双序独立控制策略下的短路电流表达式并分析了短路电流的影响因素。分析结果表明:逆变型分布式电源的正、负序电流dq轴分量是电压跌落作用下的二阶响应,三相正、负序电流由于二阶响应的超调一般呈现先逐渐增大后衰减到稳态值的趋势;逆变型分布式电源不对称故障电流的稳态值与输出的有功功率、无功功率以及正序电压、负序电压大小有关,暂态特性与变流器的控制参数以及故障瞬间电流相位紧密相关。PSCAD仿真和录波数据验证了理论推导的正确性。分析方法能够有效地表征逆变型分布式电源的故障特征,为通过变流器并网元件的故障特征分析和相关继电保护研究提供了理论参考。In order to reveal the fault characteristics and fault mechanism of IIDG（Inverter Interfaced Distributed Generator）,the fault current expressions under independent control strategy of positive-sequence and negative-sequence components are deduced based on the thought of power balance and controllable characteristics. Then the influencing factors of fault current are analyzed. The analytical results show：the daxis and q-axis components of positive-sequence and negative-sequence currents are second order response to voltage dip,and the trend of the three-phase positive-sequence and negative-sequence currents are firstly increasing gradually and then decreasing to a steady value due to the overshoot of second order response;the steady-state value of the positive-sequence and negative-sequence currents are related to the active power output,reactive power output and positive-sequence and negative-sequence voltages,and transient characteristics are closely related to control parameters of converter and current phase at the moment that fault occurs. Simulation on PSCAD and recording data verify the correctness of the theoretical deduction. The proposed analysis method can effectively reflects the fault characteristics of IIDG and provide theoretical reference to fault characteristic analysis of inverter’s interfaced components and related relay protection.

关 键 词：逆变型分布式电源 网侧变流器 不对称故障电流 故障分析 短路电流 

分 类 号：TM761[电气工程—电力系统及自动化]