How to improve the working efficiency of the motor

Reducing rotor loss

The loss of the motor's rotor is mainly related to the rotor resistance and the current passing through the rotor. The main methods to reduce the loss of the motor's rotor winding include reducing the resistance of the rotor winding and increasing the rotor slot sectional area.A thick conductor with low resistivity can be used.At present, the rotor guide bars of small and medium-sized squirrel cage motors are mostly made of cast aluminum. If copper guide bars are used, the loss can be reduced by 10% ~ 15%.

Reduce the stator copper damage

Since the electrical power on the resistor W=I2R, the loss of the stator winding can be reduced by reducing the resistance value and the current.The main methods are as follows: a. Expand the sectional area of stator slots.Because this can reduce the magnetic circuit area, increase the tooth magnetic density.B. Increase the full rate of stator slots.C. Shorten the end length of stator winding as much as possible.Obviously, reducing the length of the winding end can reduce the stator winding resistance.Usually, the end loss of the stator winding accounts for 1/4 ~ 1/2 of the total loss of the winding.D. Development of rare earth permanent magnet synchronous motor.Removing the excitation winding and excitation current can not only simplify the structure, but also improve the efficiency and power factor.

Reduce electron iron loss

Methods to reduce the iron loss of electric motors include: A. Use cold rolled silicon steel sheet.The cold rolled silicon steel with good permeability, stable quality and low loss can significantly reduce hysteresis loss and conveniently reduce the thickness of silicon steel to reduce eddy current loss.B. Reduce magnetic density.The magnetic flux density is reduced by increasing the length of the core.C. Iron chip insulation coating with superior performance shall be adopted.D. Adopt advanced heat treatment and manufacturing technology.After cold rolled silicon steel sheet is processed by punching, shearing, bending and so on, mechanical stress and strain will occur, and the magnetism will change with the change, which will lead to the increase of iron loss.Therefore, it is necessary to heat treatment to restore its original magnetic properties, which can reduce the loss of 10% ~ 20%.At the same time, it is necessary to speed up the development of new cold-rolled silicon steel sheet so that the iron loss will not change much after it is processed into iron core.

Reduce the motor stray loss

The stray loss of induction motor is mainly caused by the high frequency loss of magnetic field harmonics in fixed rotor winding and iron core.Generally, it accounts for 0.5% ~ 3% of the input power.The main methods to reduce the stray loss are as follows: a. Improve the stator winding design to reduce harmonics.B. Improve the cutting and machining method of the rotor surface and the insulation treatment of the inner surface of the rotor slot.C. Replace the traditional insulation groove wedge with magnetic groove mud or wedge to weaken the tooth groove effect and reduce additional stray loss.

Reduce ventilation friction loss

A. Since the high-efficiency motor adopts measures such as selecting high-quality materials and optimizing design, the temperature rise of the motor is relatively low, so the size of the fan can be appropriately reduced.B. Properly design the ventilation structure, using axial flow or tilting fan.C. Use higher quality bearings.