Three-level Buck conversion control method of X-shaped symmetrical H bridge and implementation device thereof

Abstract

The invention relates to the technical field of power conversion and provides a high-efficient and low-cost level Buck direct current conversion method and an implementation device thereof. In the method, a direct current power supply is input and divided into three levels through two series capacitors with the same capacity values; an upper bridge arm of the left half bridge of an X-shaped symmetrical H bridge is connected in series through two power switches and connected with the midpoint of the series capacitor on the direct current input side through a clamping diode, and a lower bridge arm is a high pressurization power diode; the left half bridge and the right half bridge are an X-shaped symmetrical half bridge; the output ends of the left and right half bridges can output three-level voltages, and the difference of the three-level voltages is a three-level narrow-pulse direct voltage output by the X-shaped symmetrical H bridge; the output ends of the left and right half bridges pass through a filter circuit connected in series with a filter inductor and a filter capacitor; stable direct current output voltage can be obtained from both ends of the filter capacitor; and the energy can be provided to a load. The invention is mainly applied to the stable direct current output voltage.

Description

technical field [0001] The invention relates to the technical field of power electronic power conversion, in particular to a control method and an implementation device for an X-type symmetrical H-bridge three-level Buck converter. Background technique [0002] With the continuous development of industrial and agricultural production and the needs of transportation, various DC electrical equipment has higher and higher requirements for power supply voltage. The power supply of the low-voltage equipment in the electric locomotive powered by the high-voltage DC transmission line generally uses the voltage of the high-voltage DC transmission line to obtain a lower DC voltage through high-frequency inverter, high-frequency transformer step-down, and high-frequency rectification, from high-voltage DC to In the conversion process of low-voltage direct current, three intermediate conversion links have been passed, which not only increases the equipment cost and the volume of the de...

AI Technical Summary

Problems solved by technology

[0005] In terms of the PWM voltage output by the converter, the dv / dt generated by the traditional two-level Buck converter is high, which will inevitably cause serious electromagnetic interference

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