How To Improve The Efficiency Of The Motor

The efficiency of the motor is mainly determined during the design. For example, the efficiency of a permanent magnet synchronous motor is higher than that of an AC asynchronous motor. If you need more higher efficiency, you need to choose a servo control system instead of a variable frequency speed control system. Of course, the cost is much higher correspondingly.

To improve the efficiency of the motor, the essence is to reduce the motor loss. The loss of the motor is divided into mechanical loss and electromagnetic loss. For example, for an AC asynchronous motor, current through the stator and rotor windings will produce copper loss and conductor loss, and the magnetic field in the iron will cause eddy current and bring about hysteresis loss. The high-order harmonics of the breath magnetic field will generate stray loss on the load, and there will be wear loss during the rotation of the bearing and the fan.

To reduce the loss of the rotor, you can reduce the resistance of the rotor winding, use thicker and lower resistivity wire, or increase the slot cross-sectional area of the rotor. Of course, the material is very important. If the conditions for the production of copper rotors are possible, the loss will be reduced by 15%. The current asynchronous motors are basically aluminum rotors, so the efficiency is not so high.

There is also copper loss on the stator, which can increase the slot surface of the stator, increase the full-slot ratio of the stator slots, and shorten the end length of the stator winding. If permanent magnets are used instead of the stator windings, there is no need to pass current. Of course, the efficiency can be obviously improved, which is the fundamental reason why synchronous motors are more efficient than asynchronous motors.

For the iron loss of the motor, you can use good quality silicon steel sheets to reduce the loss on the hysteresis, or lengthen the iron core length, which can reduce the magnetic flux density and increase the insulation coating. In addition, the heat treatment process is also critical. The ventilation performance of the motor is more important. If the temperature is high, the loss will of course be great. You can use the corresponding cooling structure or additional cooling method to reduce the friction loss. High-order harmonics will produce stray losses in the windings and iron cores, which can improve the stator windings and reduce the generation of high-order harmonics. It can also be insulated on the surface of the rotor slot and use magnetic groove mud to reduce the magnetic slot effect.