Phase dislocation control single-stage power factor correction control circuit and switching power supply

Abstract

The invention discloses a phase dislocation control single-stage power factor correction control circuit and a switching power supply, and the circuit comprises a power grid input Vin, a rectifier bridge DB, a capacitor C1, a capacitor C2, a capacitor C3, a switching tube S1, a switching tube S2, a switching tube S3, a switching tube S4, a switching tube S5, a switching tube S6, a diode D1, a diode D2, an inductor L1, an inductor L2, a transformer T1, a first output rectification circuit, an output capacitor Co, a power factor correction phase dislocation control circuit and a resonance phasedislocation control drive circuit. The invention has the beneficial effects that circuit device overstress can be prevented, a power factor correction function is achieved, the design of the filter issimplified, and the service life of the capacitor is prolonged; and the circuit is simple, convenient to control and low in cost, can well consider bus capacitor voltage and power factors, and can besuitable for wider input and output load ranges.

Description

technical field [0001] The invention relates to the technical field of circuits and switching power supplies, in particular to a phase-staggered control single-stage power factor correction control circuit and a switching power supply. Background technique [0002] In the field of power supply, driving power supply with high power density, high efficiency and low cost is more competitive. Usually the drive power will choose a resonant circuit to achieve high power density and high efficiency. The resonant circuit can realize the zero-voltage turn-on of two or more switching tubes on the primary side and the zero-current turn-off of the rectifier diode on the secondary side, which can reduce the switching loss of the power supply and improve the efficiency and power density of the power converter. At the same time, in order to improve the power factor, an active PFC power factor correction circuit is often added in the front stage of the resonant circuit, but this will lead ...

AI Technical Summary

Problems solved by technology

However, a resonant circuit with a charge pump has the following problem: When the circuit is under operating conditions in which the amplitude of the input voltage varies within a certain range, when the amplitude of the input voltage increases and the energy required to resonate the main circuit does not change , the voltage on the bus capacitor increases immediately; or, when the output power of the resonant main circuit changes within a certain range (that is, the power required by the resonant main circuit changes within a certain range), the output power decreases and the input voltage remains unchanged , the voltage on the bus capacitor increases immediately

[0006] In view of this, how to limit the voltage stability of the bus capacitor to a certain voltage value, avoid the voltage pressure on the device due to the high voltage of the bus capacitor, and achieve better power factor correction in a wide input and load range, It can also solve the problem of excessive input current ripple and bus current ripple, which has become a technical problem to be solved urgently by those skilled in the art

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