Control method and control device of air conditioner compressor

Abstract

The invention provides a control method and control device of an air conditioner compressor. The control method of the air conditioner compressor includes the following steps that work modes of an air conditioner are obtained, wherein the work modes include the first work mode and the second work mode; work frequency of the compressor is detected in real time; when the air conditioner operates in the first work mode and the current work frequency of the compressor is smaller than or equal to a first frequency threshold, the air conditioner is controlled to output a control signal in a first modulation mode to control rotation speed of the compressor; when the current work frequency of the compressor is larger than the first frequency threshold, the air conditioner is controlled to output a control signal in a second modulation mode to control rotation speed of the compressor. By means of the control method and control device of the air conditioner compressor, stability of the air conditioner operating at low frequency can be improved, operation frequency of the air conditioner compressor can be lowered to the largest extent, energy consumption is lowered, the largest operation frequency of the air conditioner compressor can be improved, and meanwhile temperature of a power device is controlled to the in a preset range.

Description

technical field [0001] The invention relates to the technical field of compressor control, in particular to a control method and a control device for an air conditioner compressor. Background technique [0002] At present, in the air conditioner products, the DC inverter air conditioner occupies a dominant position because of its advantages of energy saving and good comfort. After the air conditioner is running, the output of the maximum capacity of the air conditioner directly affects the actual cooling effect of the air conditioner. Generally, the cooling effect of the air conditioner can be improved by increasing the operating frequency of the compressor. However, increasing the operating frequency of the compressor will cause the temperature of the power device to rise sharply. In order to ensure the reliability of power devices, only the heat sink can be increased or additional heat dissipation air ducts or heat dissipation devices can be designed. [0003] In addition...

AI Technical Summary

Problems solved by technology

Theoretically, the two-phase PWM modulation method reduces the switching times by 33.3% compared with the three-phase PWM modulation method. However, the two-phase PWM modulation method has more serious distortion when sampling a single resistor current, especially at low speed and low current.

Although the three-phase PWM modulation method can obtain a relatively ideal current reconstruction effect, the switching loss is serious when the motor is running at high speed, and the temperature of the radiator rises sharply

[0004] However, only using two-phase PWM modulation, the output waveform distortion of the compressor is very serious when the compressor is running at low frequency, especially in order to improve the energy saving effect, the minimum operating frequency of the compressor needs to be reduced, thus limiting the minimum operating frequency of the compressor frequency, and causes the compressor to be less stable at low frequencies

In addition, only the three-phase PWM modulation method is adopted. When the compressor is running at high frequency, the switching loss of the power device will increase sharply under the condition of high current. The current increases accordingly. In order to control the temperature of the power device within the predetermined range, it is necessary to reduce the operating frequency of the compressor. Therefore, the three-phase PWM modulation method restricts the maximum operating frequency of the compressor.

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