A high-gain soft-switching DC converter and its control method

Abstract

The invention relates to a high-gain soft-switching DC converter and a control method thereof. The high-gain soft-switching DC converter includes a DC input power supply, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first diode, a second diode, and a third diode Tube, first inductor, second inductor, first capacitor, second capacitor, third capacitor, fourth capacitor, coupling inductor and load. Through the control of the four switching tubes, the high-gain soft-switching DC converter of the present invention has the advantages of high voltage gain, low input current ripple, high conversion efficiency, and small voltage stress of switching devices, and all four switching tubes can realize Zero-voltage soft switching, very suitable for non-isolated renewable energy power generation systems.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a high-gain soft-switching DC converter and a control method thereof. Background technique [0002] In recent years, under the pressure of energy crisis and environmental protection, clean energy such as solar energy and fuel cells have become important new energy sources. The output voltage of photovoltaic modules generally does not exceed 50V. In order to realize the grid connection of photovoltaic energy, the output voltage of photovoltaic modules needs to be boosted to a DC bus voltage of 380-400V. Therefore, high-gain, high-efficiency DC-DC converters have attracted more and more attention from domestic and foreign researchers. [0003] Traditional high-gain DC converters usually achieve various boost functions by adjusting the transformation ratio of coupled inductors. However, there are the following problems in achieving voltage boost simply by adju...

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Problems solved by technology

[0003] Traditional high-gain DC converters usually achieve various boost functions by adjusting the transformation ratio of coupled inductors. However, there are the following problems in achieving voltage boost simply by adjusting the transformation ratio of coupled inductors: the voltage stress of switching devices is high, and the coupled inductors Voltage spikes caused by leakage inductance will increase the voltage stress of the switch or diode, reducing reliability and efficiency, and causing serious EMI problems

In addition, traditional non-isolated DC converters usually cannot achieve soft switching of all switching devices, which greatly affects the efficiency of the converter

[0004] At the same time, for new energy sources such as photovoltaics and fuel cells, the input current ripple of the boost converter will not only affect the power generation efficiency, but also affect their service life, so the high-gain DC converter must have as small an input current as possible ripple

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