Bidirectional vehicle-mounted charger circuit integrated with DC/DC converter

Abstract

The invention discloses a bidirectional vehicle-mounted charger circuit integrated with a DC / DC converter, which comprises a bidirectional AC / DC circuit and a bidirectional DC / DC conversion circuit; the bidirectional DC / DC conversion circuit comprises a transformer, two H-bridge switching circuits and a full-wave rectification circuit; the first H-bridge switching circuit is connected with the first winding through the first resonance circuit, and the second H-bridge switching circuit is connected with the second winding through the second resonance circuit; first ends of two half-wave rectification branches of the full-wave rectification circuit are respectively connected with two ends of the third winding, second ends of the two half-wave rectification branches are connected with a firstend of an output end of the full-wave rectification circuit, and a center tap of the third winding is connected with a second end of the output end of the full-wave rectification circuit. The half-wave rectification branch comprises a rectifier tube and a chopper tube, the rectifier tube and the chopper tube are connected in series in a common-source mode, the rectifier tube and the chopper tubeof the half-wave rectification branch are switched on at the same time, the chopper tube and a switching tube at the dotted terminal of the input side winding are switched off at the same time, and the rectifier tube is switched off in a delayed mode relative to the chopper tube. According to the invention, the voltage stress of the half-wave rectification branch switching tube can be reduced, andthe breakdown risk is reduced.

Description

[technical field] [0001] The invention relates to a bidirectional vehicle charger, in particular to a bidirectional vehicle charger circuit integrating a DC / DC converter. [Background technique] [0002] The traditional electric vehicle on-board charger and on-board DC / DC converter are separate modules that work independently, and the on-board power conversion part has a large volume and weight. [0003] The invention with the application number CN201710559537.5 discloses a new type of on-board charger main circuit with integrated DC / DC converter and its control loop, which electrically integrates the DC / DC converter and on-board OBC, and can realize on-board OBC Two-way energy transmission; in addition, the control strategy of synchronous rectification + PWM pulse width modulation wave transmission is adopted on the battery side to maximize the efficiency of DC / DC functional modules; and the volume of the whole machine is greatly reduced, the cost is significantly reduced, a...

AI Technical Summary

Problems solved by technology

This control method is simple, but in the actual circuit, since the output current of the low-voltage winding often reaches more than 100A, when the rectifier switch and the chopper switch are turned off at the same time, due to the parasitic inductance of the line, the large current at turn-off will not Instantaneous drop to 0, causing the junction capacitance of the rectifier tube to be charged to a very high voltage, and the potential of the common source node drops, resulting in high stress on the drain-source voltage of the rectifier tube and chopper tube, and there is a risk of breakdown

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