光伏低电压穿越期间无功补偿对差动保护灵敏度的影响分析  

Impact analysis of reactive power compensation on sensitivity of differential protection during the low voltage ride-through of photovoltaic systems

作　　者：王秀莲[1] 胡广[1] 毕大强[2] 

机构地区：[1]沈阳理工大学,辽宁沈阳110168 [2]清华大学电机系电力系统国家重点实验室,北京100084

出　　处：《电力系统保护与控制》2016年第4期51-56,共6页Power System Protection and Control

摘　　要：研究了具备低电压穿越(Low Voltage Ride-Through,LVRT)能力的光伏并网发电系统,送出线部分发生三相短路故障时,LVRT控制过程中发出的无功电流对传统比率制动式和新型标积制动式差动保护灵敏度的影响。理论分析表明故障期间无功补偿会导致两种差动保护的灵敏度下降,并通过Simulink搭建光伏并网发电系统仿真模型验证了这一结论。在此基础上,进一步对比得出发生金属性短路故障时,标积制动式差动保护的灵敏度受无功补偿影响较小,作为光伏电站送出线部分的保护效果更佳。最后通过差动特性曲线的整定方式,对如何提升差动保护灵敏度的问题提出改进建议。The influence of reactive power compensation on sensitivity of differential protection of ratio-restraining characteristic and product-restraining characteristic is studied, when the output line of grid-connected photovoltaic （PV） systems with low voltage ride-through capability occurs three-phase short-circuit failures. It is found that the use of LVRT results in the decline of two kinds of sensitivity of the differential protection. The model of grid-connected photovoltaic （PV） system is set up, and verified by Simulink simulation. And further conclusion shows that the impact of differential protection of product-restraining characteristic on sensitivity is smaller, when the reactive power compensation is injected, and is better for the protection of output lines of photovoltaic power station, when the short-circuit fault occurs. Finally, this paper presents recommendations about how to improve the sensitivity of the differential protection by the tuning mode of differential characteristic curve.

关 键 词：LVRT 无功补偿 比率制动 标积制动 灵敏度 

分 类 号：TM773[电气工程—电力系统及自动化]