High-efficiency energy-saving permanent magnet synchronous motor

Abstract

The invention relates to a permanent magnet synchronous motor which comprises a stator, a rotor, at least one pair of permanent magnets and a protection magnetic circuit, wherein the rotor is rotatably arranged with the stator, the at least one pair of permanent magnets are distributed on the rotor and used for generating a magnetic source, a magnetism isolating block is arranged between the two adjacent permanent magnets, the protection magnetic circuit is arranged on the rotor and positioned between the magnetism isolating block and the permanent magnet, the magnetic resistance of the protection magnetic circuit is farther smaller than the internal magnetic resistance of the permanent magnet, and the impact magnetic flux formed from the suffered electric network transient mutation of the permanent magnets is released through the protection magnetic circuit at the moment of starting or shutting off the motor or in the operating process of the motor, thereby ensuring that the permanent magnets can always work in the safe region of a demagnetization curve, effectively protecting the permanent magnets on the motor, solving the problems of unreliable operation and unstable working characteristic of the permanent magnet motor and ensuring the service life of the motor.

Description

technical field [0001] The invention relates to a synchronous motor. Background technique [0002] The permanent magnet synchronous motor can save energy because it can greatly improve the power factor of the AC induction motor. It does not require excitation, and the rotor rotates synchronously with the magnetic field, so there is no loss of the secondary circuit. Due to the above two reasons, the permanent magnet synchronous motor can save energy by more than 10-15% than the asynchronous motor of the same power. [0003] With the improvement of people's awareness of energy saving and environmental protection, permanent magnet synchronous motors are used as high-efficiency and energy-saving general power sources to replace asynchronous motors in a large range, which has become a common consensus among people in the motor industry. Even so, the mass production of permanent magnet synchronous motors is slow. This is because the structure and process of permanent magnet sync...

AI Technical Summary

Problems solved by technology

In the past, in order to improve the reliability of permanent magnet motor operation, the passive method of increasing the air gap to increase the reluctance of the magnetic circuit and thickening the permanent magnet to increase the magnetic energy product to resist the impact of interference was often adopted, which not only sacrificed the performance index of the permanent magnet synchronous motor, It also increases the cost of materials, and the effect is not ideal. The impact of the impact magnetic potential on the demagnetization of the permanent magnet has not been solved from the root cause

[0013] Therefore, another situation can be inferred. If the permanent magnet synchronous motor is out of step due to overload and continues to run for a long time, the permanent magnet synchronous motor formed by the above structure will also generate short-circuit eddy current heating. If the heat accumulation exceeds the thermal demagnetization temperature, the same It will cause damage to the motor, but the former is caused by interference and impact magnetic potential, and the latter is caused by overload and out of step

Images