Bridgeless boost type CUK PFC circuit

Abstract

The invention relates to a bridgeless boost type CUK PFC circuit. The circuit comprises an input AC (alternating current) power supply Vin, a power switch tube Q1, a power switch tube Q2, power diodes (Q1-Q5), intermediate capacitors Cn1 and Cn2, an output capacitor Co and inductors L11, L12 and L2, wherein one end of the input power supply is connected with the anode of D1, the cathode of D2 and one end of L11, and the other end is connected with the anode of D3, the cathode of D4 and one end of L12; the other end of L12 is connected with one end of Cn2 and the drain electrode of Q2; the other end of L11 is connected with one end of Cn1 and the drain electrode of Q1; the other ends of Cn1 and Cn2 are connected to one end of L2 through the anode of D5; the other end of L2 is connected with the negative pole of CO and one end of a load RL; the cathode of D1 is connected with the cathode of D3 and connected with the negative pole of CO and the other end of the load RL; the other ends of D2, D4, Q1 and Q2 and the cathode of D5 are grounded. With the construction of the bridgeless boost type CUK PFC circuit, the conduction loss of power semi-conductor devices is reduced, and low-ripple, efficient and high-power-factor AC-DC (direct current) electrical energy conversion is realized.

Description

technical field [0001] The invention relates to a bridgeless step-up Cuk PFC AC-DC conversion circuit. Background technique [0002] Cuk chopper circuit is also called Cuk converter. The Buck-Boost improved single-tube non-isolated DC converter proposed by Slobodan Cuk of the California Institute of Technology has inductors in the input and output sections, which can significantly reduce the ripple of the input and output currents, and the polarity of the output voltage is opposite to that of the input voltage. , the output voltage can be either lower or higher than the input voltage. [0003] On the basis of the traditional Cuk converter, Slobodan Cuk proposed a step-up Cuk converter in 2000. This kind of converter is only used to realize the boost function of the converter, while retaining the advantages of the traditional Cuk converter, it realizes the unidirectional boost function; at the same time, this kind of converter has the characteristic that the polarity of the...

AI Technical Summary

Problems solved by technology

[0006] The traditional active power factor correction circuit uses the rectifier bridge as the front-stage AC-DC conversion circuit. At any time, the current must pass through at least three switching devices to form a loop. The on-state loss of the rectifier bridge affects the efficiency of the whole machine.

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