Methods for maintenance and start-up of permanent magnet motors

The vast majority of the rotor of permanent magnet motor adopts cage structure. Because of improper manufacturing, utilization, maintenance or long running time, the end cover, bearing, bearing sleeve, rotor journal, cage bar and stator core and other parts of the motor will produce wear and deformation and lose the due accuracy of shape and dimension, so that the motor will produce vibration in operation. When the vibration value exceeds the standard, the health and safety operation of the equipment will be affected. Explosion-proof motor is mainly used in coal mine, oil and gas, petrochemical and chemical industries. In addition, it is also widely used in textile, metallurgy, urban gas, transportation, grain and oil processing, paper making, medicine and other sectors. As the main power equipment, explosion-proof motor is usually used to drive pumps, fans, compressors and other transmission machinery.

The electric motor belongs to the rotary folding machine. The important object of its vibration test is the rotor or shaft. The rotor is the center of the rotating folding machine. The permanent magnet motor components are supported in the bearing seat and housing or basically through bearings (oil film bearings or rotating bearings), forming a rotor supporting system.

The energy characteristics of the support affect the movement of the rotor to a certain extent, but most of the vibration problems of the rotary folding device are directly related to the rotor. Explosion-proof motor is mainly used in coal mine, oil and gas, petrochemical and chemical industries. In addition, it is also widely used in textile, metallurgy, urban gas, transportation, grain and oil processing, paper making, medicine and other sectors. As the main power equipment, permanent magnet motor is usually used to drive pumps, fans, compressors and other transmission machinery. It is estimated that about 70% of vibration failures can be invented from rotor activity. And from bearings, housing and basically can only invent 30% of the fault. Therefore, the invention of vibration fault from rotor activity is more direct and effective than vibration information limited to the bearing seat or housing

A large number of large permanent magnet motors have greatly improved the development of soft starting techniques in China. A variety of techniques have been used in the category of soft starting, presenting a lot of new soft starting products of permanent magnet motors. Some scholars even put forward the concept of soft starting discipline.

By introducing the soft start products with different skills, the function and skill characteristics are compared to predict the development direction of soft start skills.

Traditional step-down starting method of subseries reactor step-down starting method

The series reactor in the stator loop of the permanent magnet synchronous motor can limit the starting current of the stator, which is appropriate to drop the voltage added to the motor stator. After the permanent magnet motor is started, the reactor can be removed.

Because the electromagnetic torque when the permanent magnet motor starts is proportional to the square of the voltage added on the motor stator, the inductance value of the reactor can not be selected too large, must make the motor starting torque is greater than the load torque, but also need to leave a certain margin, lest the grid voltage drop and other disturbances make the permanent magnet motor start failure. Explosion-proof motor is mainly used in coal mine, oil and gas, petrochemical and chemical industries. In addition, it is also widely used in textile, metallurgy, urban gas, transportation, grain and oil processing, paper making, medicine and other sectors. As the main power equipment, explosion-proof motor is usually used to drive pumps, fans, compressors and other transmission machinery.