Control method and control device for compressor in air conditioner

Abstract

The invention discloses a control method and a control device for a compressor in an air conditioner. The control method includes the following steps: the current operating frequency of the compressor is obtained; the operating frequencies of the compressor are divided into N preset frequency ranges, which frequency range the current operating frequency lies is judged, wherein N is an integer greater than or equal to 2; when the current operating frequency belongs to the ith preset frequency range, a weak-magnetism voltage modulation degree threshold corresponding to the ith preset frequency range is obtained, weak-magnetism current is calculated according to the obtained weak-magnetism voltage modulation degree threshold, and is injected into the compressor, wherein i is equal to 1, 2, 3, ... or N, thereby the magnitude of the weak-magnetism current injected into the compressor is controlled, consequently, by injecting appropriate weak-magnetism current into the compressor, the operating noise of the compressor can be effectively reduced, the requirement for the quietness of the air conditioner can be met, the comfort of the air conditioner is increased, moreover, the efficiency of the compressor can be optimized, and the energy-saving performance of the air conditioner can be ensured.

Description

Technical field [0001] The present invention relates to the technical field of electrical appliances, in particular to a control method of a compressor in an air conditioner and a control device of the compressor in an air conditioner. Background technique [0002] With the continuous development of inverter air conditioner technology, people have higher and higher requirements for the comfort and energy saving of inverter air conditioners. Among them, the cooling effect is an important factor affecting the comfort of air conditioners. In order to make the inverter air conditioner obtain better cooling effect, it is necessary to control the compressor to run at a relatively high frequency. However, as figure 1 As shown, the back EMF of the compressor motor will increase with the increase of the operating frequency. When the operating frequency of the compressor motor reaches the rated frequency, the back EMF will be close to the bus voltage, and it is difficult to continue to inc...

AI Technical Summary

Problems solved by technology

However, related technologies cannot control the magnitude of the field-weakening current

In practical applications, if the injected field weakening current is too small, the voltage margin of the compressor motor will be insufficient, which will cause the torque fluctuation of the compressor, especially when running at a high frequency, it will cause a large compressor noise; if the injected If the magnetic field weakening current is too large, the compressor motor current will increase, which will lead to a decrease in efficiency and an increase in power loss, thereby reducing the energy saving performance of the air conditioner.

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