Boost and buck integrated bridge-free power factor correction (PFC) circuit

Abstract

The invention discloses a boost and buck integrated bridge-free power factor correction (PFC) circuit, which comprises an alternating current input source Vin, a power metal-oxide-semiconductor field effect transistor (MOSFET) tube S1, a power MOSFET tube S2, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a diode D7, an energy storage capacitor C1, an energy storage capacitor C2, an inductor L1, an inductor L2 and a load equivalent resistor R1 and is characterized in that: a bridge-free boost circuit and a buck circuit are combined through the power MOSFET tube S1, the energy storage capacitor C1 and the diode D7; the power MOSFET tube S1 serves as one of switches of the bridge-free boost circuit and also serves as a switching tube of the BUCK circuit; and the energy storage capacitor C1 serves as an output capacitor of the boost circuit to store energy transmitted by the boost circuit and serves as an input capacitor of the buck capacitor to supply energy to a load of the buck circuit. Compared with the prior art, the boost and buck integrated bridge-free PFC circuit has the main advantages that: 1, an input rectifier bridge is saved and conduction consumption is reduced; and 2, the PFC circuit and a backward direct current-direct current (DC-DC) circuit are used in combination, and just one controller can conduct power factor correction and output voltage adjustment functions at the same time, so that fewer devices are used, efficiency is improved, and cost is reduced.

Description

technical field [0001] The invention relates to a bridgeless single-stage power factor correction (PFC) circuit. More specifically, the present invention relates to a bridgeless single-stage PFC circuit integrated with a BOOST circuit and a BUCK circuit. Background technique [0002] With the rapid development of power electronic technology, various power electronic devices are widely used in power systems, industries, transportation and households. Rectifying and supplying DC from the AC grid is a basic conversion method widely used in power electronics technology. Traditional rectifiers and diodes or thyristors form uncontrolled or phase-controlled rectification circuits, which will generate a large number of current harmonics and reactive power. Harm. Its hazards are mainly manifested in the following three aspects: causing a decline in the quality of power supply; affecting the reliability of the power grid; causing a decrease in the utilization rate of electric energy...

AI Technical Summary

Problems solved by technology

The correction effect of this PFC circuit is relatively ideal, but when it is working, the rectifier bridge and the power factor correction stage circuit have three semiconductor power devices conducting at the same time, the conduction loss is relatively high, and the energy has to pass through the power factor correction stage and the subsequent DC- DC circuit processing has problems such as many components, high cost, and low circuit efficiency.

Images