Full-range soft switching method of input-series output-paralleled phase-shifted full-bridge convertor

Abstract

The invention relates to a full-range soft switching method of an input-series output-paralleled phase-shifted full-bridge convertor, and belongs to the technical field of isolated type direct current-direct current convertors. The method includes the steps that one series LC network is connected into the position between the center point of a leading bridge arm upper tube and a leading bridge arm lower tube of a first phase-shifted full-bridge conversion module and the center point of a lag bridge arm upper tube and a lag bridge arm lower tube of a second phase-shifted full-bridge conversion module, the other series LC network is connected into the position between the center point of a lag bridge arm upper tube and a lag bridge arm lower tube of the first phase-shifted full-bridge conversion module and the center point of a leading bridge arm upper tube and a leading bridge arm lower tube of the second phase-shifted full-bridge conversion module, and then zero-voltage switching of MOSFETs is achieved. The method can automatically adapt to different input voltages, output voltages and loads. According to the method, full-range soft switching of the phase-shifted full-bridge convertor can be achieved, efficiency of the whole convertor is improved, the method is suitable for the occasion where high-voltage input is converted into low-voltage output, and the requirements for the wide input voltage range, the wide output voltage range and the wide load change range are met.

Description

Technical field [0001] The invention relates to a full-range soft switching method for input-series-output parallel phase-shifting full-bridge converters, and belongs to the technical field of isolated direct current (DC-DC) converters. Background technique [0002] High-voltage input and low-voltage output are widely used in industry. In order to overcome the limitations of device selection, solutions to high-voltage input and low-voltage output are roughly divided into: (1) device series; (2) multi-level technology; (3) converter series topology. Because of the simple topology, the device series technology is applied by ABB in HVDC transmission. In order to achieve the equalization of the voltage of each device, a great test is still put forward to the design of the control system. Multi-level technology can adapt to high-voltage input occasions, but in practical applications, three-point level and five-level applications are still the main ones. As the number of levels incr...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that the lagging bridge arm is not easy to realize zero-voltage turn-on (ZVS) at light load in the phase-shifted full-bridge converter with the input connected in series and the output connected in parallel. A general method for full-range soft-on soft-on of phase-shifted full-bridge converters connected in parallel

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