In the water projects, several types of water pumps are its main facilities. These water equipment has a common feature, which is low water head and high water flow. Therefore, the water equipment is mainly low speed pumps below 400R/min. At present, most low -speed pumps adopt asynchronous+reducer or directly use low speed motors to drive.The first drive solution has low system efficiency, complex conduction method, large noise vibration. And the second drive solution with the problem of low power factor and large volume.

With the development of permanent magnet technology, especially high torque low speed synchronous permanent magnet driving, which provides a new type of energy saving and environmental friendly solution for low head and high flow water pump. The permanent low -speed high torque motors have small volume, light weight, high torque , high efficiency, high power factor, strong overload capacity, etc., and can be widely used in several equipment of low speed high torque transmission. The related matched control system has achieved soft control of the motor speed, and small starting current has realized as well. The operation is also very simple.