Control method and control system of APFC circuit voltage, and air conditioner

Abstract

The invention provides a control method of an APFC circuit voltage. The control method comprises the steps that a direct-current bus voltage and an input alternating-current voltage peak value are detected in real time, the operation frequency of a current compressor is obtained, and the voltage withstanding value of a device is obtained; according to the operation frequency of the current compressor, the input alternating-current voltage peak value and the device voltage withstanding value, a voltage given value of an APFC circuit is obtained through calculation; and the direct-current bus voltage detected in real time is compared with the voltage given value, and the voltage of the direct-current bus output by the APFC circuit is kept constant by adjustment. The invention further provides a control system of the APFC circuit voltage and an air conditioner. According to the calculation method of the voltage given value of the APFC circuit provided by the invention, the voltage of thedirect-current bus output by the APFC circuit is adjusted according to the voltage given value, so as to achieve the maximization utilization rate of the direct-current bus voltage; and meanwhile, byvirtue of the boosting property of the APFC circuit, different AC input voltages can be adapted.

Description

Technical field [0001] The present invention relates to the technical field of electrical appliance control, in particular to a control method, control system and air conditioner of APFC circuit voltage. Background technique [0002] APFC (active power factor correction) circuit can improve the power factor and stabilize the DC voltage. It has been used in inverter air conditioners and similar household appliances. In the prior art, the APFC circuit topology commonly used in single-phase power inverter air conditioners is as figure 1 As shown, AC power supplies power to the permanent magnet synchronous motor through AC-DC-AC conversion; the APFC circuit topology commonly used in three-phase power inverter air conditioners is as follows figure 2 As shown, the AC input terminal passes through the input inductor L A , L B , L C Connected to the grid, the DC output terminal is connected to the load after the output filter capacitor. [0003] The DC bus voltage plays a role as a link b...

AI Technical Summary

Problems solved by technology

Therefore, the output voltage of APFC must be reasonably controlled. If it is too high, it will lead to low utilization rate of DC voltage, increase the withstand voltage of the device, and increase the cost; if it is too low, it will not meet the normal operation requirements of the compressor and affect the operating performance of the motor.

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