Single-phase rectification and charging circuit

Abstract

The invention provides a single-phase rectification charging circuit which can be applied to the application occasion where a three-phase or single-phase AC-DC converter is used as a pre-stage circuit. The single-phase rectification charging circuit comprises a rectifying unit, a judging unit and a driving unit, wherein the rectifying unit is used for completing the soft electrifying and rectifying process; the judging unit is used for judging whether the current-limiting resistance cutoff conditions are met or not; the driving unit is used for completing drive and breakover for a power MOSFET. The single-phase rectification charging circuit has soft electrifying and rectifying functions; moreover, the circuit is simple and has the advantages of multiple functions, low cost and the like.

Description

technical field [0001] The invention relates to a rectifying circuit powered by a single-phase AC power supply, in particular to a single-phase rectifying and charging circuit which detects the average value of charging current. Background technique [0002] For power electronic conversion equipment powered by AC power with a diode rectifier circuit, such as frequency conversion household appliances or industrial frequency converters, the issue of soft power-on needs to be considered. Otherwise, because the initial electrolytic capacitor voltage is zero, the power electronic conversion device will have an overcurrent fault during the power-on stage, resulting in overvoltage breakdown of the subsequent stage converter and air switch action. [0003] Among the commonly used power-on current-limiting measures, most of them adopt the method of adding a current-limiting resistor in the AC or DC line, which specifically includes three methods: (1) The current-limiting resistor is ...

AI Technical Summary

Problems solved by technology

The problem with the first two methods is: the secondary current impact problem is brought about when the resistance is cut off

The problem with the latter method is that it is only suitable for applications with a load power below 200W

[0005] Based on the above, the retrieval of the existing circuit structure of the soft power-on rectifier circuit found that there is no soft power-on control scheme that can detect the power-on charging current at the current stage, and it is still necessary to introduce a new type of integrated drive unit and soft power-on function. The rectifier circuit has the advantages of simple structure, complete functions and low cost.

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