Totem-pole bridgeless power factor correction circuit of soft switch

Abstract

The invention discloses a totem-pole bridgeless power factor correction circuit of a soft switch. The circuit comprises a boost inductor, input current sampling, totem-pole bridgeless topology, a resonant passive network, a filter circuit, output voltage sampling, a control circuit, and voltage zero-crossing detection. Through adding the resonant network formed by an inductor, a capacitor, and a diode passive element on a totem-pole bridgeless topological main circuit, each PWM duty ratio period of two switching devices on the positive and negative half cycles of an input power supply is controlled, one switch is used as a main switch, and the other one is used as a resonant switch. The circuit realizes that an auxiliary power switch is not needed and the two switching devices on the totem-pole bridgeless topology work in a soft switching state of zero voltage conduction and zero current shutoff. Circuit efficiency is improved, and rated values of the switching devices are reduced. The circuit can operate in a current discontinuous mode, a critical conduction mode, and a current continuous mode, and is suitable to be used in low, intermediate, and large and various power. A dead-time is not needed to be set, thereby preventing the two switching devices from connecting directly and being in short circuit, and improving reliability of the circuit.

Description

technical field [0001] The invention relates to power electronics, in particular to a soft switch totem pole bridgeless power factor correction circuit. Background technique [0002] Totem-pole Bridgeless Power Factor Correction circuit (Toem-pole Bridgeless Power Factor Correction) is a topology that can achieve high efficiency and low electromagnetic interference, such as figure 1 As shown, it consists of two switching devices in series S 1 , S 2 and two rectifier diodes in series D 1 、D 2 composition. Since the two switching devices S 1 , S 2 On one bridge arm, in order to prevent through short circuit, it is necessary to set dead time. The topology can only work in discontinuous current mode and critical conduction mode, and cannot work in continuous current mode. Simultaneously both switching devices S 1 , S 2 Working in the hard switching state, the loss is relatively large, and power devices with large ratings are required when working at high frequencies, wh...

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Problems solved by technology

Since the two switching devices S 1 , S 2 On one bridge arm, in order to prevent direct short circuit, dead time must be set, the topology can only work in discontinuous current mode and critical conduction mode, and cannot work in continuous current mode

Simultaneously both switching devices S 1 , S 2 Working in the hard switching state, the loss is large, and it is necessary to use a power device with a large rating when working at high frequency, which increases the cost of the circuit

Therefore, the totem pole bridgeless power factor correction circuit is not suitable for medium and high power applications

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