向家坝水电站7号机组过速试验中接力器异常开启的受力过程分析

Analysis on stress process of servomotor abnormal start-up during over-speed test for No.7 hydropower generating unit of Xiangjiaba Hydropower Station

向家坝水电站首台7号机组在机械过速试验紧急停机过程中,导叶接力器在关至17%开度左右时,突然异常开启至23%开度左右,然后再按照剩余关机规律关闭至全关,显然整个关机曲线不符合关机规律,无法满足机组安全运行要求。现场决定用试验录波的方法,对导叶接力器在整个关闭过程中的受力情况进行分析,明确受力突变原因,找出解决方法。

During the emergency shut-down of the machinery over-speed test made on the first unit——No. 7 hydropower generating unit of Xiangjiaba Hydropower Station,when the guide vane servomotor shuts down the guide vane to the opening of about17%,the abnormal start-up with the opening of about 23% abruptly occurs,after that,shuts down to the full-closing with the remain shut-down law; for which the whole shut-down curve is obviously not coincide with the law of the shut-down. At the site,it is determined to analyze the stress state during the whole shut-down process of the guide vane servomotor,so as to define the causation of the abrupt change of stress and find out the relevant solving method.