Permanent magnet synchronous motor low frequency control method, device, compressor and air conditioner

Abstract

The embodiment of the invention, which belongs to the field of permanent-magnet synchronous motor control, provides a low-frequency control method and device of a permanent-magnet synchronous motor, a compressor and an air conditioner. The method comprises: after starting of a permanent-magnet synchronous motor, an electromagnetic torque is obtained and a first mechanical position angle is determined; according to the electromagnetic torque and the first mechanical position angle, an instantaneous load torque of the permanent-magnet synchronous motor is determined; a torque compensation current is determined by using the determined instantaneous load torque and a mapping relationship between an instantaneous load torque and a torque compensation current; and torque compensation is carried out on the permanent-magnet synchronous motor based on the torque compensation current. According to the low-frequency control method and device, the electromagnetic torque and the mechanical position angle are used as inputs; and compared with the mechanical rotation speed, the high-frequency noises are reduced; and no filter link needs to be set additionally for inputted noises. Therefore, accurate compensation currents are provided; the phase lag is small; and the anti-interference capability is high.

Description

technical field [0001] The invention relates to the field of permanent magnet synchronous motor control, in particular to a permanent magnet synchronous motor low-frequency control method, device, compressor and air conditioner. Background technique [0002] The permanent magnet synchronous motor is a synchronous motor that is excited by a permanent magnet to generate a synchronous rotating magnetic field. The permanent magnet acts as a rotor to generate a rotating magnetic field. The three-phase stator winding reacts through the armature under the action of the rotating magnetic field to induce a three-phase symmetrical current. Due to low cost and simple process, most of the compressors used in household small wall-mounted air conditioners are single-rotor compressors using permanent magnet synchronous motors. However, due to the structural characteristics of the single-rotor compressor, the load torque is unstable during operation, resulting in large vibrations, and the t...

AI Technical Summary

Problems solved by technology

Since the compressor generally adopts positionless control, the feedback speed is an estimated speed value, which often contains some high-order harmonic components, which is likely to cause interference

At the same time, due to the setting of filtering and other links, a certain degree of phase angle deviation is often caused, resulting in inaccurate compensation current and unsatisfactory vibration suppression effect.

[0004] For the above technical problems, there is no good solution in the prior art

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