Power factor correction control circuit and driving power supply

Abstract

The invention discloses a power factor correction control circuit and a driving power supply. The power factor correction control circuit comprises a power grid input Vin, a rectifier bridge DB1, a capacitor C1, a capacitor C2, a switching tube S1, a switching tube S2, a switching tube S3, a diode D1, an inductor L1, a resistor R1, a transformer T1, a first output rectification circuit, an outputcapacitor Co, a power factor correction control circuit and a resonance control driving circuit. The power factor correction control circuit and the driving power supply of the invention have the advantages that a circuit device can be prevented from being overstressed, and a power factor correction function is achieved; the circuit is simple and convenient to control; compared with a two-stage circuit, the circuit cost is low; compared with passive charge pump PFC, bus capacitance voltage and power factors can be both taken into consideration; and the power factor correction control circuit and the driving power supply are suitable for wide input and output load ranges.

Description

technical field [0001] The invention relates to the technical field of circuits and driving power supplies, in particular to a power factor correction control circuit and driving 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 to complex circuits and high costs. [000...

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

[0004] At the same time, the charge pump PFC, as a passive measure, is difficult to achieve ideal power factor correction in a wide input and load range, and the power factor and harmonic effects are not ideal

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