What is the reason why earth permanent magnet motors save power?

Nowadays, earth permanent magnet motors are widely used in various industries because they have the advantage of saving power. So how can this kind of equipment achieve such a good power-saving effect? The following article will introduce the reasons why earth permanent magnet motors save power. I hope everyone can benefit from it after reading it.

When the three-phase stator winding of the earth permanent magnet motor (each phase difference is 120° electrical angle) is supplied with a three-phase alternating current with a frequency f, a rotating magnetic field will be generated that moves at a synchronous speed. In a steady state, the main pole magnetic field will follow the The stator rotates synchronously with the rotating magnetic field, so the rotor speed is also synchronous speed. The stator rotating magnetic field always remains relatively stationary with the main pole magnetic field established by the permanent magnet. They interact with each other and generate electromagnetic torque, driving the motor to rotate and converting energy.

The permanent magnet variable frequency air compressor uses a high-efficiency permanent magnet motor inverter (PM motor). The screw host and the high-efficiency permanent magnet motor share the same main shaft. The earth permanent magnet motor has no bearings. The rotor with permanent magnets is directly installed on the male rotor. When stretched out on the shaft, its transmission efficiency can reach 99%. This structure eliminates the failure points of traditional motor bearings and enables maintenance-free earth permanent magnet motors.

The combination of earth permanent magnet motors with power electronics technology and microcomputer control technology has improved the performance of motors and transmission systems to a new level. High-efficiency permanent magnet variable frequency motors always maintain high efficiency under load and save 38% energy compared to ordinary motors. % or more, more than 10% energy saving than induction variable frequency motor. After the motor is stopped, its performance can be started immediately. It can be started and stopped unlimited times without affecting the life of the motor. The starting current does not exceed the full load current.

Since the earth permanent magnet motor has the advantage of low speed and high output torque, its frequency conversion control mode is wider than that of the ordinary induction variable frequency motor. The permanent magnet variable frequency motor is 30% smaller in size and 35% lighter in weight than a motor with the same power, making maintenance easier. Improving the performance and level of supporting technical equipment is an important development direction for the motor industry to adjust its industrial structure.

Since the earth permanent magnet motor has the characteristics of high remanence density, high coercivity and high magnetic energy product, it can also allow the motor to have a larger air gap length and air gap density. Therefore, in terms of permanent magnet placement and magnetic circuit structure, It has great flexibility in design and can be made into different structural shapes and sizes from traditional motors, such as disc motors, slotless motors, etc., according to the use occasions, especially the needs of automobiles, computers and aerospace engineering. This can not only further reduce the mass and moment of inertia of the motor and improve the response sensitivity of the motor; it can also reduce the pulsation of the motor's torque and increase the smoothness of operation; it can also simplify the structure and process of the motor. Therefore, it has been widely used in computer peripherals, office equipment and situations requiring precise positioning control.