Three-phase APFC correction circuit and method and air conditioner

Abstract

The invention provides a three-phase APFC correction circuit and method and an air conditioner. The three-phase APFC correction circuit comprises: three-phase voltage sources for providing three-phasealternating current; three first bridge arms, wherein one end of each first bridge arm is connected with each of the three-phase voltage sources, and the other ends of at least two first bridge armsare connected with one resistor; and a processing circuit connected to at least two resistors for determining current flowing through the at least two resistor in one PWM period and further obtainingthe three-phase current of the three-phase alternating current. The sampling of the three-phase current is improved, and the three-phase current can be determined by the current on the at least two resistors, thereby avoiding the use of the current sensor, and achieving the sinusoidalization of the three-phase current while saving cost.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a three-phase APFC correction circuit, method and air conditioner. Background technique [0002] At present, three-phase power inverter air conditioners have been widely used, but there will be problems of power harmonics during their use. In order to solve this technical problem, the prior art generally uses a three-phase APFC (active power factor correction) control circuit, which requires sampling the current and voltage signals of the three-phase power supply, but because the current signal and the control circuit do not share the same ground, Therefore, the prior art generally adopts isolated current sensors (S1\S2) to sample the three-phase circuit, obviously, the component cost of the three-phase APFC control circuit will be very high. Contents of the invention [0003] In view of this, the present invention aims to propose a correction circuit, method and air ...

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Problems solved by technology

[0002] At present, three-phase power inverter air conditioners have been widely used, but there will be problems of power harmonics in the process of using them.

In order to solve this technical problem, the prior art generally uses a three-phase APFC (active power factor correction) control circuit, which requires sampling the current and voltage signals of the three-phase power supply, but because the current signal and the control circuit do not share the same ground, Therefore, the prior art generally uses isolated current sensors (S1\S2) to sample the three-phase circuit. Obviously, the device cost of the three-phase APFC control circuit will be very high.

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