An energy feedforward buck soft switch circuit and device

Abstract

The invention provides an energy feedforward buck soft switching circuit and device, including: a buck circuit, an auxiliary soft switching circuit; the buck circuit includes a power supply, a main switching circuit, a load and a filter circuit, and the auxiliary soft switching circuit includes: a transformer, a resonant circuit, the first auxiliary switch circuit; the power supply is electrically connected to the primary circuit of the transformer through the first auxiliary switch circuit, wherein the primary circuit of the transformer includes a resonant circuit and a primary winding, the resonant circuit is electrically connected to the primary winding, and the filter circuit The main switch circuit is electrically connected to the primary circuit of the transformer, and the secondary circuit of the transformer is electrically connected to the load; the energy of the resonant circuit is transmitted to the load through the transformer. Based on the invention, through the cooperation of the auxiliary soft switching circuit and the transformer, while realizing the soft switching, the resonant energy is directly transmitted to the load, thereby improving the conversion efficiency of electric energy.

Description

technical field [0001] The invention relates to the field of step-down choppers, in particular to an energy feedforward type buck soft switch circuit and device. Background technique [0002] With the continuous development of science and technology, higher requirements are put forward for the efficiency, power density and reliability of DC / DC converters. In the existing technology, please refer to figure 1 (a) Transformer TR solution, during the whole working process of the resonant inductor Lr, the energy is fed back to the input power supply E through D4, which is equivalent to the resonant energy circulating between Lr and E, figure 1 (b) Transformer ATR scheme, during the rising process of iLr, the resonant current circulates in the autotransformer; but the energy of Lr is finally fed back to the input power supply E through D3, please refer to figure 2 , considering the influence of the parasitic capacitance of the actual device S, D and the leakage inductance of the...

AI Technical Summary

Problems solved by technology

[0002] With the continuous development of science and technology, higher requirements are put forward for the efficiency, power density and reliability of DC / DC converters. In the existing technology, please refer to figure 1 (a) Transformer TR solution, during the whole working process of the resonant inductor Lr, the energy is fed back to the input power supply E through D4, which is equivalent to the resonant energy circulating between Lr and E, figure 1 (b) Transformer ATR scheme, during the rising process of iLr, the resonant current circulates in the autotransformer; but the energy of Lr is finally fed back to the input power supply E through D3, please refer to figure 2 , considering the influence of the parasitic capacitance of the actual device S, D and the leakage inductance of the coupling inductance, the oscillation problem is serious, resulting in excessive voltage and current stress, and at the same time, the resonance energy is transmitted to the output side after two transformations through the coupling inductance. As mentioned above, the resonance energy of the existing technical solutions is either fed back to the input power supply or transferred to the output side after two transformations, which will inevitably affect the improvement of efficiency

At the same time, some schemes still have problems of excessive voltage and current stress

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