一起风电场解列保护拒动的分析及改进措施

Analysis on Protective Action Resistance for Fault Disconnection of Wind Farm and Its Improving Measures

摘要:

集中式并网风电一方面要防止在系统轻微故障时机组脱网，另一方面在风电场升压站本侧送出线故障时要 求能迅速解列。针对工程中一起典型的风电场升压站本侧送出线接地故障后解列保护拒动的事故进行了分析，遵循 风电场低电压穿越特性，通过增加进线保护动作辅助判据，对低压解列保护进行了改进。改进后保护即可在系统轻 微故障时保障风机不脱网连续运行，维护了并网风机的经济效益; 同时又保证了在风电场升压站本侧送出线故障时 可迅速解列风电，提高了电网的安全稳定性。

关键词:低电压穿越; 低压解列; 风电场; 继电保护

Abstract:

The large － scale grid － connected wind farm should avoid taking off the grid when minor faults occur on one hand， on the other it needs to isolate promptly as soon as the own outgoing line faults of boost station of wind farm occurs． A protective action resistance for fault disconnection of wind farm after the typical ground fault of outgoing line in booster station is analyzed，and following the low － voltage ride － through characteristics of wind farm，the under － voltage isolation protection is improved by adding outgoing line protections as auxiliary criterion． After the improvement，the protections ensure the wind farm in continuous operation will not be taken off the grid when minor faults occur，which maintains the economic benefits of wind farm． Meanwhile it ensures the prompt isolation when the faults of own outgoing line in boost station occur，which improves the safety and stability of power grid．

Key words:low － voltage ride － through; under － voltage separation; wind farm; relay protection