基于预测控制的电机变频/工频同步切换

Motor synchronous switching between variable frequency and power frequency based on predictive control

针对大功率变频器与工频电源切换不当引起电机产生冲击电流和转速波动的问题,提出了一种预测控制的交流电机变频/工频同步转换控制方案.采用TMS320F2812 DSP芯片对变频器输出电压和工频电压信号进行同步采样,通过鉴相运算得到两路输入信号的相差信号,然后调用预测控制算法程序实现锁相控制.当变频器输出电压与工频电网电压相位达到一致时,DSP控制继电器动作,从而实现电机由变频电路到工频电网平稳、无扰切换.仿真结果表明,该设计方案具有快速性、优良的跟踪特性和很强的鲁棒性.

According to the problem that a high-power inverter and a power improper cause impact current and speed fluctuations due to improper switching,a synchronous switching method is developed between the variable frequency and power frequency of an AC asynchronous motor based on predictive control.The inverter output voltage signal and power frequency voltage signal synchronized are sampled by using TMS320F2812 DSP chip,and the difference between two input signals is obtained by a phase operation.Then it calls the predictive control algorithm procedures to achieve phase lock control.When the inverter output voltage and power frequency voltage phase achieve consistently,DSP will control a relay so as to realize that a motor switch from a frequency conversion circuit to a power grid smoothly and without interference.The simulation results show that the design has fast and excellent tracking characteristics and strong robustness.