基于单片机控制的电机变频/工频同步切换

Motor Synchronous Switching between Inverter Power and PowerFrequency Supply Based on MCU Control

研究了一种单片机控制的交流电机变频/工频同步切换控制方案,设计由鉴频鉴相控制部分、PI调节器和变频器构成的锁相同步切换控制方案。单片机通过对工频信号和变频器输出电压信号进行实时的相位检测并构成锁相环,实现相位跟踪,当2个信号频率一致且相位误差在合理的范围内时,单片机控制交流接触器吸合,实现电机由变频器到工频电网的安全平稳切换。实验结果验证了该装置具有良好的运行性能。

This paper develops a synchronous switching method between variable frequency and power frequency of AC asynchronous motor based on MCU control. The phase-locked synchronous switching control scheme is designed,which consists of frequency and phase discriminator,PI regulator and frequency converter. In order to achieve phase synchronization tracking,a phase-locked loop is realized by real-time detection of MCU to phase signals of variable frequency and power frequency. The MCU controlled contactor coils action when phase error between variable frequency and power frequency was within allowable range and synchronous switching or non-impact switching was achieved. And devices have a good operating performance indicated by results.