Cascaded resonance DC-DC conversion circuit combined with inductor and capacitor

Abstract

The invention relates to a power electronic electric energy conversion circuit and discloses a cascaded resonance DC-DC conversion circuit combined with an inductor and a capacitor. The front and rear cascaded circuits together utilize an inductor and a capacitor, namely the filter inductor contained in the PWM DC-DC circuit is simultaneously regarded as the input decoupling inductor of the rear cascaded DCX circuit while the resonance capacitor of the DCX circuit is simultaneously regarded as the output capacitor of the PMW DC-DC output capacitor; the switching frequency of the PWM DC-DC circuit synchronizes with that of the DCX circuit. In the conversion circuit, the front and rear cascaded inductors and capacitors are compound to promote power density; the DC-DC output voltage can be flexibly adjusted by the two-stage cascaded topological structure; wastage of the power switching tube switch is reduced through the parallel resonance technology of the soft switch; the energy conversion efficiency is promoted by collecting energy from the parasitic inductor or the capacitor; the energy consumption of the circuit is reduced and the energy is also saved; heat energy of the power switch apparatus is also decreased to improve the operation steadiness of the circuit and the service life of the apparatus and the circuit.

Description

technical field [0001] The invention relates to a power electronic electric energy conversion circuit, in particular to a two-stage cascaded current source input type resonant DC-DC circuit with inductance compounding. Background technique [0002] The topology of the current source input DC transformer (hereinafter referred to as the current source input DC transformer circuit as DCX circuit) is as follows: figure 1 As shown, it is a method to build a resonant soft switching circuit, by moving the resonant capacitor to the DC side of the input, and inserting an inductor between the capacitor and the input voltage source as a current source, the rest is the same as the traditional DC-DC circuit Similarly, the soft switch is realized by using the capacitor Cr to resonate with the inductance Lr in the circuit. Wherein, the inductance Lr may be an external independent inductance, or the leakage inductance of the transformer. When the switch tube is turned on, the capacitor Cr...

AI Technical Summary

Problems solved by technology

[0004] In the common two-stage cascading scheme, the two stages work independently, so each stage requires its own passive energy storage components, such as filter inductors and capacitors, resulting in a large number of components, large volume, and reduced power density, especially in the front The inductance of the first-stage PWM type DC-DC and the inductance of the subsequent current source are large, which seriously affects the power density

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