AC-DC synchronous rectification circuit and control method thereof

Abstract

According to a capacitive AC-DC synchronous rectification circuit and a control method thereof, the functions of rectification, PFC, voltage transformation and voltage stabilization between AC and DCare achieved through a circuit composed of a first-stage capacitor and a switch, the structure of an AC-DC switching power supply formed through the technology is effectively simplified, the efficiency is improved, the electromagnetic radiation problem of an inductive switching power supply is fundamentally solved, and the capacitance transduction type switching power supply is realized. The mainprinciple is that VDC is equal to M * D * VAC, wherein VDC is direct-current output voltage, M is the voltage ratio of an output target value to an input instantaneous value, D is the duty ratio of PWM of a switch, and VAC is the instantaneous value of AC220V. M, D and a switch bridge of a hardware circuit are used for modulation together, so that the VDC outputs stable direct-current voltage.

Description

technical field [0001] The invention belongs to the electric energy conversion between alternating current and direct current, and its main function is to realize the rectification of alternating current and stabilize the voltage to output direct current. Background technique [0002] The main structure of the current inductive switching power supply includes input rectification, PFC, input filtering, switching transformer, rectifying output, and filtering. The entire circuit structure is relatively complex, bulky, and there are problems such as electromagnetic radiation, surge, and electromagnetic shielding of the switching transformer. Contents of the invention [0003] The invention proposes a capacitive AC-DC synchronous rectification circuit and a control method thereof, and uses a first-stage capacitive switch circuit to realize rectification, PFC, and voltage stabilization output functions between AC and DC. [0004] Such as figure 1 It is a capacitive 4-stage sync...

AI Technical Summary

Problems solved by technology

[0002] The main structure of the current inductive switching power supply includes input rectification, PFC, input filtering, switching transformer, rectifying output, and filtering. The entire circuit structure is relatively complex, bulky, and there are problems such as electromagnetic radiation, surge, and electromagnetic shielding of the switching transformer.

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