I want to change the speed of an AC motor by changing the frequency of the current that power it. How can I do this?
Controlling the speed of an AC motor is usually done by changing the driving angle of the current we apply to it, which is achieved through circuits with SCRs or Triacs. The change in frequency does influence speed, but there is a serious problem with adopting this solution: when we reduce the frequency of a motor, we also change the induction process, affecting the induced field in the metal core which then becomes lossy. in the form of heating. In short, by reducing the frequency we have losses that translate into heat. If the reduction is steep, heating may endanger the integrity of the motor.
