inverter for motor 1-phase AC 220V 3HP

[Tamch4]

hello!
I have a project motor speed control 220V AC 3HP! I refer to the design using Triac and DIAC. experimental when I feel the engine heat up during operation at a slower rate. I need some advice or a solution to complete your project! are looking forward to help!

 

[Harald Kapp]

I'm not an expert in motor control. From what you describe it may be possible that the motor is self-cooling (meaning it has an internal fan driven by the rotation of the motor axle) but at low rpm the speed is too low for the fan to be effective. Therefore the motor gets warm/hot.
Just to get a feeling whether it is the motor or your control circuit that causes the problem: Try to drive the motor by a lower voltage AC source, e.g. an adjustable transformer set to 110 V or lower. Does the motor still become warm? Then you may have to cool it by an external fan.