The YD series variable pole multi speed three-phase asynchronous motor is a stepwise variable speed motor that changes the motor speed and power by changing the wiring method of the winding. This series of products adopts a single winding pole changing method to achieve speed conversion, and is divided into two speed and three speed motors. It has the advantages of wide applicability, good starting performance, reliable operation, and convenient maintenance. This series of products is suitable for various types of mechanical equipment that require variable speeds (not suitable for fans and pumps), with simple structure, small size, low noise, and low price.