Totem-pole bridgeless PFC circuit, power conversion device and air conditioner

Abstract

The invention discloses a totem-pole bridgeless PFC circuit, a power conversion device and an air conditioner. The totem-pole bridgeless PFC circuit comprises at least one upper bridge arm MOS tube, at least one lower bridge arm MOS tube, an inductor, a filter capacitor and at least one bootstrap circuit, wherein each upper bridge arm MOS tube and the lower bridge arm MOS tube are connected in series to form a switch bridge arm circuit; the bootstrap circuit corresponds to the number of the switch bridge arm circuits; the output ends of a driving power supply circuit are respectively connectedto a grid electrode of the lower bridge arm MOS tube and the input end of the bootstrap circuit; the output end of the bootstrap circuit is connected to a source electrode of the upper bridge arm MOStube, wherein the driving power supply circuit is used for driving the conduction of the upper bridge arm MOS tube and / or the lower bridge arm MOS tube; and the bootstrap circuit and the driving power supply circuit form a charging loop for storing electric energy when the corresponding lower bridge arm MOS tube is conducted. According to the totem-pole bridgeless PFC circuit, the power conversion device and the air conditioner, a problem that the upper bridge arm MOS tube cannot be reliably conducted due to the fact that the bootstrap capacitor cannot be charged or has insufficient charge.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a totem pole bridgeless PFC circuit, a power conversion device and an air conditioner. Background technique [0002] The totem pole bridgeless PFC circuit is a new type of circuit that replaces the traditional rectification circuit, because it can reduce the rectification loss, so it is more and more used in the field of power supply technology. [0003] The existing totem-pole bridgeless PFC circuit has a half-bridge circuit of the upper and lower arm switches, and usually requires a floating power supply when driving the upper arm switches, and most of them use bootstrap capacitors to provide floating power for the upper arm switches. [0004] However, this kind of bootstrap capacitor needs to be charged in the initial charging preparation state. If the totem pole bridgeless PFC circuit is used to drive the upper and lower bridge arm switch tubes at this time, the chargi...

AI Technical Summary

Problems solved by technology

[0005] The main purpose of the present invention is to propose a totem pole bridgeless PFC circuit, a power conversion device and an air conditioner, aiming to solve the problem that the bootstrap capacitor cannot be charged or is insufficiently charged so that the upper bridge arm MOS tube cannot be reliably turned on

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