电网负荷波动导致调速器工作模式切换原因分析

某大型电站的并网机组多次在电网负荷波动期间发生多台机组调速器工作模式切换,即同时由功率反馈模式切换至开度反馈模式运行,考虑到该电站高水头、长隧洞、大容量引水发电系统的特殊性1],该运行模式会给机组和电网的安全稳定运行带来风险。为此,开展了分析工作,研究分析认为,造成调速器工作模式切换的原因为调速器功率传感器误报警,为了降低调速器功率传感器在电网负荷波动期间的误报警率,在调速器控制程序中引入频率作为电网负荷波动时防止功率传感器误报警的条件。完善后的程序在被试机组上已经稳定运行了8个月,在此期间,电网负荷发生波动时,再未发生功率传感器误报警及调速器控制模式切换的现象,说明优化完善措施取得了良好的效果。

Analysis of cause for operation mode switch over of turbine governor resulted from grid load fluctuation

During grid load fluctuation,the unit operation mode of the turbine governor of a large hydropower station switched over from power feedback mode to opening feedback mode.This operation mode could put the unit and grid at risk due to the special water diversion and power generation system of the hydropower station with high water head,long diversion tunnel and large capacity.The analysis showed that the cause for the switch over of the operation mode was false alarm of the power sensor of the governor.To lower the false alarm rate during the grid load fluctuation,the frequency of the generator was introduced to the controlling program of the governor as a condition.The new program has being running steadily for eight months without any false alarm or switch over of the operation mode during grid load fluctuation,which proves that the improvement measures are effective as expected.