Switching loss reduced single-stage power factor correcting circuit

Abstract

This invention discloses a single-step power factor correction circuit for reducing switch loss, in which, a HF transformer includes two primary windings, and a pair of same-name ends are connected with the leakage of a switch tube, a mode of mutual couple of two windings is applied to put an inductance device for correcting input current waves in front of a rectifying bridge to improve the magnetic interference of the single-step PFC circuit at the same time when correcting power factors, when a switch tube is off, part of energy stored in the primary PFC inductor and the leakage inductor of the feedback winding is provided to the capacitor for charging and the other part is transmitted to secondary capacitor by the transformer directly so as to reduce loss brought with leakage inductance of the feedback winding and the switch loss and increases the efficiency.

Description

technical field [0001] The invention relates to a power factor correction circuit, in particular to a single-stage power factor correction circuit for reducing switch loss. Background technique [0002] The power factor correction circuit widely used at present is often the traditional two-stage power factor correction technology, but its circuit components are many, the cost is high, and the circuit is complicated, so it is not suitable for small and medium power applications. In order to reduce the cost of the two-stage power factor correction circuit, various single-stage power factor correction techniques have been proposed in recent years. A general single-stage power factor correction circuit automatically realizes the power factor correction function by controlling the inductor current to work in a discontinuous conduction mode. In order to achieve the balance of input and output power while ensuring the hold-up time of the power supply, a low-frequency capacitor is ...

AI Technical Summary

Problems solved by technology

However, when the switch tube SW is turned on, the inductor L P current and winding N 1 The current flows through the winding N 2 , the current of this winding is larger; when the switch tube SW is disconnected, the winding N 2 The leakage inductance of the switching tube SW will cause a large peak voltage between D and S, increasing the loss caused by the leakage inductance, and the switching loss of the switching tube SW

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