一起齿盘测速误动原因分析及解决措施

Cause Analysis of Misoperation in Speed Measurement of Fluted Disc and Solutions

某抽水蓄能电站在发电工况停机及水泵工况运行过程中,多次发生齿盘测速探头误报高转速信号,造成过速保护跳机故障。通过现场试验及对涡流测速原理的比较分析,发现由于高转速机组对涡流测速探头精度要求很高,而机组在运行中,开机或停机时,在连续上升的频段或连续下降的频段中,它所传导的振动对齿盘测速容易造成干扰,导致误报高转速信号。通过将支架改为三角形支撑,并将安装位置由下导底面改装在基座水泥上,解决了问题。

Abstract： In the shutdown under the working condition of electricity generating of water pump of a pumped storage power station, the false reporting of high rotation speed signals by the speed measurement probe of fluted disc frequently occurs, causing over-speed protection trip faults.Through the field test and the comparative analysis of eddy current speed measurement principle, it is found out that since the unit of high rotation speed has a very high requirement for the accuracy of eddy current velocity measurement probe, while during the operation of the unit, upon start or stop, and during the continuously rising frequency band or the continuously falling frequency band, the vibration transmitted by the set is liable to interfere with the speed measurement of fluted disc, causing false reporting of high rotation speed signals.That problem will be solved by changing the support to a triangular support and changing the installation position from the lower guide plane to the cement foundation.