A Wide-Ratio Transformerless Buck-Boost Converter

Abstract

A wide ratio transformerless buck-boost converter mainly consists of 5 power switches S 1 ~S 5 , 3 polar capacitors C 1 ~C 3 and 1 inductor L 1 composition, C 1 The negative pole is connected to the low voltage terminal V L the positive and L 1 one end, C 1 The positive pole is connected to S 1 one end and S 2 one end, S 2 The other end is connected to S 3 one end and C 2 the positive pole, S 3 The other end is connected to S 5 one end and C 3 the positive pole, S 1 the other end of , C 2 the negative pole and C 3 The negative pole is connected to L 1 the other end and S 4 one end, S 5 The other end is connected to the high voltage terminal V H the positive pole, S 4 The other end is connected to the low voltage terminal V L The negative and high voltage terminals of V H the negative pole, in the boost / buck state, S 2 , S 3 and S 4 Used as a power switch / synchronous rectifier, S 1 , S 5 Used as a synchronous rectifier / power switch, the present invention can solve the problems of low voltage conversion ratio and high switching voltage stress, achieve high voltage gain and low switching voltage stress, and is especially suitable for use as a buck-boost unit during charging and operation of electric vehicles .

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and can be applied to the fields of new energy vehicles and the like, and particularly relates to a transformerless buck-boost (two-way DC-DC, which can realize both step-up and step-down) converter with a wide ratio. Background technique [0002] Compared with traditional vehicles, new energy vehicles have the following advantages: [0003] 1. Zero emissions or near zero emissions. Fuel cells combine hydrogen and oxygen through electrochemical methods to directly generate electricity and heat, and discharge water without polluting the environment. [0004] 2. Diversification of energy sources. [0005] 3. The conversion efficiency of the battery is high (about 60%), and the fuel economy of the whole vehicle is good. [0006] For new energy vehicles, the most important unit is the buck-boost unit. This is an important component of the connection between the battery of the new ener...

AI Technical Summary

Problems solved by technology

[0011] In order to overcome the shortcomings of the above-mentioned bidirectional DC converter in the prior art and solve the problems of low voltage conversion ratio and high switch voltage stress, the purpose of the present invention is to provide a transformerless buck-boost converter with wide variable ratio, which can realize high voltage gain and low switching voltage stress

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