西寺坪电站卧式机组过速分析及处理

Analysis and Processing Methods of Horizontal-type Unit Over-speed for Xisiping Plant

针对西寺坪电站在甩负荷后转至孤网运行过程中,出现的多台机组成组调节过程中振荡过速的情况,研究了调速器比例—积分—微分(PID)控制模型,找出了事故原因,提出了调速器程序及参数的处理方法,认为当系统频率大于52Hz时,若PID比例项的增量输出大于0,将PID比例项的增量输出清零;当系统频率小于48Hz时,若PID比例项的增量输出小于0,亦将PID比例项的增量输出清零;当系统频率介于48~52 Hz之间时,正常PID调节。之后通过现场试验验证了修改后调速器的性能。结果表明,修改后调速器调节性能反应良好。研究结果为相似运行方式条件下的多机组成组调节提供借鉴。

During the process of Xisiping hydropower plant load rejection and transferring to isolated power grid running,several units appear the phenomenon of oscillation over-speed during the group unit regulation.We have studied the control model of PID governor and found out the malfunction reasons.And then the treatment method of governor program and parameters was proposed.when the system frequency was greater than 52 Hz and the PID ratio increment output was greater than 0,the PID ratio increment output should be reset.When the system frequency was less than 48 Hz and the PID ratio output was less than 0,the PID ratio output should be reset.When the system frequency was in the range of 48 and 52Hz,the PID regulation should be in the normal way.The property of governor after correction was verified by site test.This study can provide reference for the other several unit regulations under the similar running conditions.