Magnetic integrated self-driving current-double rectification half-bridge three-level direct-current converter

Abstract

The invention discloses a magnetic integrated self-driving current-double rectification half-bridge three-level direct-current converter, comprising an input partial-voltage capacitor circuit, a half-bridge three-level bridge arm, an isolated transformer, a driving circuit and a rectification and filtering circuit. According to the magnetic integrated self-driving current-double rectification half-bridge three-level direct-current converter, voltage stress of a main switch tube is reduced through a half-bridge three-level topology without a flying capacitor and an embedded diode, and a problem of reliability of the embedded diode of the conventional half-bridge three-level topology is solved at the same time; conduction loss of a vice-side rectification tube is reduced by a synchronous rectification proposal; the conduction loss of a vice side of a transformer is further reduced by a current-double rectification technology, and the efficiency is improved; the structure and the volume of a converter are simplified through a magnetic integration and automatic driving scheme; and the main transformer integrates output filter inductance therein by utilizing a two-transformer primary-side serial-connection vice-side alternating parallel connection structure so that the power density of the converter is improved.

Description

technical field [0001] The invention relates to a DC converter of an electric energy conversion device, in particular to a magnetically integrated self-driven current-doubler rectifier half-bridge three-level DC converter without flying capacitors and clamping diodes. Background technique [0002] With the continuous improvement of human living standards, the demand for electric energy has increased significantly. Low-voltage and high-current output devices have been developed rapidly, such as in the electroplating industry, communication industry, and railway industry. When the output power is less than 2.5KW, two-phase power supply is usually used for power supply, and when the output power is greater than 2.5KW, three-phase power supply is used. Power supply, at this time, the three-phase power input passes through the PFC circuit, boosts the voltage to about 800VDC, and then obtains the required DC voltage through the DC-DC circuit. If a conventional DC-DC converter is ...

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Problems solved by technology

However, increasing the resonant inductance will lead to the loss of the duty cycle of the secondary side, and the small resonant inductance will make the converter unable to achieve soft switching at light loads. When the driving duty cycle is not equal in the positive and negative half cycles, it is connected to the flying capacitor The embedded diode will generate instantaneous large current, which affects the reliability of the converter. When it is applied to low-voltage and high-current output occasions, the loss of the secondary rectifier diode is very large, which seriously affects the efficiency of the converter.

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