大型同步电机变频启动系统的调试技术

Debugging Technology of SFC Start System for Large Synchronous Motor

通过某大型空压机组同步电机LCI变频启动系统的调试案例,介绍了大型同步电机LCI变频启动系统的调试技术,包括调试、差动保护故障排查、电机“反转-正转”问题调试。针对该调试案例中电机带机组无法启动、启动初始阶段电机发生2~3次小幅度“反转-正转”再正常转动,分析启动过程电机磁通、转子位置、励磁电流、定子电流波形,介绍了如何优化LCI变频器电压信号采样位置及直流补偿磁通角度和延时释放晶闸管脉冲等参数,从而解决机组启动初始阶段电机小幅度反转问题。

Through a debugging case of LCI variable frequency start system of a large air compressor's synchronous motor,the debugging technology of LCI variable frequency start system of large synchronous motor is introduced,including debugging,differential protection fault troubleshooting,and motor"reverse forward"problem debugging.In this commissioning case,the motor and unit could not be started.At the initial stage of starting,the motor had 2~3 times of small amplitude"reverse forward"and then rotated normally.The motor magnetic flux,rotor position,excitation current and stator current waveform during startup are analyzed.The problems of how to optimize the sampling position of voltage signal of LCI inverter,DC compensation flux angle,delayed release thyristor pulse and other parameters,so as to solve the problem of small amplitude reversal of motor at the initial stage of unit startup.