Full bridge converter with zero voltage and zero current

Abstract

The present invention discloses a zero voltage zero current full-bridge DC-DC converter. Diodes are respectively and reversely connected in parallel with two ends of lead arm switching tubes and lagging switching tubes. Capacitors C1,C3 are connected in parallel with the lead arm switching tubes S1,S3. A homonymous terminal at the primary side of a transformer TX1 is connected to a transmitting terminal of the lead arm switching tube S1. A synonymous terminal at the primary side of the transformer TX1 is connected to an inductor LIK. A homonymous terminal of the secondary side of the transformer is connected to the anode of a diode D6, while a synonymous terminal of the secondary side is connected to the anode of a diode D5. An output coupling inductive circuit is added to the cathodes of the diodes D5,D5 and two ends of the center of the secondary side of the transformer. The output coupling inductive circuit mainly consists of a clamp capacitor Ch, an output coupling inductor Lc, and diodes Df,Dd,Dc. The converter can realize zero voltage zero current soft switching at a wider load range. Auxiliary circuits have no dissipative elements. The inductor does not need to store energy in advance. The stress of the current at the primary side is not increased.

Description

technical field [0001] The invention relates to a DC / DC (direct current / direct current) power conversion device, in particular to a PWM (pulse width modulation) full-bridge converter which utilizes an output coupling inductance to realize zero-voltage and zero-current switching. Background technique [0002] At present, the zero-voltage and zero-current soft-switching full-bridge DC / DC converter circuit is a soft-switching technology for the main switching circuit. There are two commonly used circuit structures. One is as follows: figure 1 As shown in the full bridge structure, the super forearm switch S 1 , S 3 and the lagging arm switch S 2 , S 4 Both ends of the anti-parallel diode D 1 、D 3 、D 2 、D 4 , then in D 1 、D 3 on the shunt capacitor, C 1 、C 3 . In Transformer TX 1 The end with the same name on the primary side is connected to C b end of the C b The other end of the connection S 1 on the transmitter side of the transformer TX 1 The non-identical e...

AI Technical Summary

Problems solved by technology

The disadvantages of the circuit structure of these two full-bridge DC / DC converters are: 1. Due to the existence of the saturated inductance Ls in the main switch circuit, not only the loss of the duty cycle is caused, but also the design of the saturated inductance and the selection of magnetic materials are more difficult ; 2. The diode D connected in series with the lagging bridge arm 2 、D 4 Increase the on-state loss of the circuit, thus limiting the improvement of the maximum efficiency of the circuit

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