CAJ | 학술논문

孤岛运行时光伏电源继续向负载供电，会给检修人员和用户设备带来安全隐患，快速有效地实现孤岛检测具有重要意义。提出了一种通过并网逆变器注入负序电流并检测公共连接点电压不平衡度的快速孤岛检测方法。通过合理投切负序电流注入降低了对电网的干扰，不受电网不对称故障的影响且无检测盲区。在光伏电源功率与负荷功率匹配、公共连接点电压和频率基本不发生偏移的情况下对该方法进行了仿真验证，结果表明即便在这种最不利于孤岛检测的情况下，该方法仍能快速准确地检测出孤岛运行状态。
고도운행시광복전원계속향부재공전，회급검수인원화용호설비대래안전은환，쾌속유효지실현고도검측구유중요의의。제출료일충통과병망역변기주입부서전류병검측공공련접점전압불평형도적쾌속고도검측방법。통과합리투절부서전류주입강저료대전망적간우，불수전망불대칭고장적영향차무검측맹구。재광복전원공솔여부하공솔필배、공공련접점전압화빈솔기본불발생편이적정황하대해방법진행료방진험증，결과표명즉편재저충최불리우고도검측적정황하，해방법잉능쾌속준학지검측출고도운행상태。
The photovoltaic power source would keep supplying power under unscheduled islanding operation, and hence bring potential risk for maintenance personnel and electric equipments, so it is of great significance to enforce accurate and rapid islanding detection method. A method based on negative sequence current injection and voltage imbalance on the point of common coupling is proposed. The reasonable switching strategy of negative sequence current in the grid-connected inverter reduces the impact of injected current on the main power grid. The method, without non-detection zone, is also unaffected by asymmetric faults of the power grid. Case study shows that the method could detect islanding state accurately and quickly under the worst condition while the power of the PV matches the load power, and the voltage and the frequency of the PCC has small shift.