Novel wide-range input power converting circuit

Abstract

A novel wide-range input power conversion circuit which accords with a wide-range input condition is composed of a voltage pre-adjusting unit and an output voltage adjusting unit and an output voltage adjusting unit, wherein the voltage pre-adjusting unit and the output voltage adjusting unit are connected through an inductor unit. The voltage pre-adjusting unit comprises a pair of leg which are connected with two ends of input voltage. The midpoint of each leg is connected with one end of an inductor unit. The output voltage adjusting unit is a power converter which is composed of a pair of legs, a bus capacitor and a power conversion network. The midpoint of the leg is connected with the other end of the inductor unit and finishes a voltage increase function together with the bus capacitor. The leg and the power conversion network form a topological circuit such as an LLC topological circuit and a full-bridge topological circuit. Through multiplexing the legs, the number of power devices is reduced, loss is reduced and efficiency is improved. Through adjusting the duty ratio of the two legs, adjustment for output voltage of a conversion circuit is realized. Through adjusting the conduction time sequence of two leg switches, soft switching on-and-off of all switching tubes is realized. An adjusting unit and an output voltage adjusting unit can be realized in a parallel or staggered parallel manner.

Description

Technical field: [0001] The invention relates to the field of switching power supply power conversion. The invention proposes a novel topology circuit structure. Under the condition of a wide range of input voltage, two-stage power control is realized by using the fewest devices, and all switch tubes can work in a soft switching state, so that high efficiency and high power density can be realized more conveniently. . Background technique [0002] Under the condition of wide range of input voltage and wide range of output voltage, there are usually two ways to complete the isolation voltage conversion of medium and high power: [0003] One is to use a first-stage phase-shift full-bridge circuit to directly complete the voltage conversion, and the design can ensure that all high-voltage switch tubes can achieve soft switching. This design is simple and reliable, and can achieve high efficiency. However, in order to ensure that the maximum output voltage can be maintained u...

AI Technical Summary

Problems solved by technology

This solution can realize the soft turn-on of a full range of switching devices, and can achieve high frequency and high efficiency; but the disadvantage is that there are too many power devices, which is not conducive to cost control and high power density. The control of the BOOST circuit is complicated. Once the control parameters are unreasonably designed, zero-voltage switching cannot be realized, or the RMS current is too large, and it is difficult to achieve high efficiency.

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