Input parallel and output parallel combination converter under control of common phase-shifting angle

Abstract

The invention discloses an input parallel and output parallel combination converter under the control of a common phase-shifting angle. A main circuit comprises more than two phase-shifting circuits under the control of the common phase-shifting angle; each phase-shifting circuit consists of a transformer with leakage inductance and two bridge circuits which are connected through the transformer;and the input ends of all the phase-shifting circuits are connected in parallel and the output ends of all the phase-shifting circuits are connected in parallel. Under the control of the common phase-shifting angle, input current of all the phase-shifting circuits is equal and output current of all the phase-shifting circuits is equal, natural current sharing is realized, current sharing control loops are not needed to be added, each phase-shifting circuit unit is not needed to be subjected to current sampling, control is greatly simplified, power density and stability of the combination converter are improved, and cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and relates to related technologies of input parallel output parallel converters in the field of DC / DC conversion, and in particular to parallel current sharing technology of distributed power sources. Background technique [0002] As the power level increases, the transformer volume of the converter will increase, and the magnetic loss and the current stress of the switch tube will also increase accordingly, which limits the efficiency and power density of the converter. Connecting two or more converters in parallel at the input and output ends can reduce the power level of a single converter, thereby ensuring that the single converter works in a better state. In addition, each converter is usually interleaved in parallel to reduce the input and output current ripple, thereby reducing the size of the input and output filter capacitors. In view of the above advantages, the input paral...

AI Technical Summary

Problems solved by technology

Therefore, the converter that shares more current bears greater electrical stress and thermal stress than other converters, and is prone to failure and aging, thereby reducing the reliability and efficiency of the entire converter

[0004]Currently, current sharing methods are roughly divided into two categories: droop method and active current sharing method, but these current sharing methods The method basically requires current sampling for each converter unit. If digital control is used, an analog-to-digital converter (ADC) needs to be added for each additional current sampling point, and the current sharing performance of the current sharing loop is limited by the sampling accuracy. , even adding a current sharing ring cannot guarantee a very good current sharing effect, and the design of the current sharing ring for n converter units is relatively complicated

In summary, adding a current sharing ring reduces the power density and reliability of the combined converter, and increases cost and control complexity

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