Air conditioner and its defrosting control method and defrosting control system

Abstract

The present invention provides a defrosting control method of an air conditioner, comprising: a step of reducing frequency, when the air conditioner is in the heating mode, if it is detected that defrosting is required, the operating frequency of the compressor of the air conditioner is reduced; The detection step is to detect the current waveform state of the compressor when it is running in real time; the frequency determination step is to determine the target frequency when the compressor exits low-frequency torque compensation according to the current waveform state; When the operating frequency of the compressor is equal to the target frequency, the heating mode is switched to the defrosting mode, and the operating frequency of the compressor is increased to start defrosting. Correspondingly, the present invention also provides an air conditioner defrosting control system and an air conditioner. Through the technical proposal of the present invention, the compressor can not be stopped during defrosting, and the heating effect is improved, the reliability of the air conditioner is improved, and the user experience is improved.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to an air conditioner defrosting control method, an air conditioner defrosting control system and an air conditioner. Background technique [0002] With the development of air-conditioning technology, the application of frequency conversion air-conditioning is becoming more and more popular. In the low temperature environment, the heating capacity of the inverter air conditioner is higher than that of the fixed frequency air conditioner, and in order to further increase the heating capacity in the low temperature environment, many inverter models adopt the control method of not stopping the compressor in the defrosting mode. When the air conditioner enters the defrosting mode, the inverter compressor first performs frequency reduction processing. After reducing to low frequency, the four-way valve reverses direction, and then the compressor increases frequency again, and th...

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Problems solved by technology

However, this control method has a fatal flaw: when the single-rotor compressor is reduced to low-frequency operation, the pressure on the rotor is constantly changing due to the constant change of the pressure in the compressor cylinder, and the adjustment action of the controller has a certain The hysteresis, the offset of the center of gravity of the rotor will cause mechanical vibration of the compressor, especially at low frequencies, which will cause fluctuations in the speed of the compressor, thus introducing a torque compensation method at low frequencies

However, when the four-way valve is switched, due to the high and low pressure difference in the system, the sudden switch from the heating mode to the cooling mode causes the pressure to be unbalanced. At this moment, the compressor just turns on the torque compensation function, and the current waveform of the compressor can be detected by the oscilloscope It is very messy, and it is easy to cause the compressor to stop abnormally. After the compressor restarts, it will directly transfer to the heating mode without defrosting. After running for a long time, the frost on the outdoor heat exchanger will increase. , the heating effect of the air conditioner will be severely deteriorated, and if things go on like this, there will be compressor liquid shock, which will eventually lead to compressor damage

However, if the four-way valve is reversing when the compressor is running at high frequency, the pressure difference between the high and low pressure of the system will be too large, which will cause a great impact on the four-way valve and affect the service life of the four-way valve.

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