一次风机电动机绝缘损坏原因分析与处理

Cause Analysis of Insulation Damage on Primary Fan Motor and Its Treatment

某热电厂2×150 MW循环流化床机组于2012年7月完成一次风机变频改造,采用一拖一自动工频/变频切换运行方式。2017年4月,1号锅炉在机组启动过程中因变频器散热风扇未送电导致变频器高温跳闸,造成2号一次风机频繁启动,使其电动机绕组绝缘损坏,导致1号锅炉一次风风量不足,给机组的安全稳定运行带来安全隐患。分析认为,一次风机电动机绕组绝缘损坏是由电动机绕组绝缘老化、绕组出槽口处遭受电动力冲击等导致。对此提出了相应防范措施,确保采用变频运行的电动机长周期安全稳定运行。

2×150 MW circulating fluidized beds in a thermal power plant has adopted the operation mode of one dragging one self-motion/frequency conversion in July, 2012. In April, 2017, in the process of boiler No.l starting up, the inverter tripped due to fan cooling without operation, frequency start up of No.2 primary fan, motor winding insulation damage fault occur, causing insufficient air volume, which brings the safe and stable operation of the hidden dangers to the unit. Make an analysis of the factors causing the motor winding insulation aging, the motor winding by electromagnetic torque between the rabbets, impacting over the voltage, the over current, and the fever, etc. Put forward the corresponding preventive measures to ensure the safe and stable operation of the motor with frequency conversion operation.