Active soft switch semi-bridge method

Abstract

The invention provides an active soft switch half bridge method, which is characterized in that: a push-pull type BUCK topology is adopted and connected in series in a main circuit of a half bridge topology through two inductors Lo1 and Lo2; auxiliary switches VS11 and VS12 are used for respectively carrying out CUK to actively realize the zero-voltage disconnection of ZVS soft switch; main switches VS1 and VS2 are respectively connected in series with the small magnetic integrated inductors Lo1 and Lo2 to form zero-current conducting of ZCS soft switch; passing through a load RO, output alternating current is then connected in series with a current-limiting inductor Lr and reaches a middle point P of half bridge capacitors C1 and C2, to form a push-pull type BUCK half bridge topology. The active soft switch half bridge can eliminate the straight-through dangers in the traditional half bridge circuits, effectively improve the reliability and electrical efficiency and reduce EMC interference levels, and can be widely used in LED lamps, HID lamps, single-phase, two-phase or three-phase flicker free fluorescent lamps, single-phase, two-phase or three-phase power electronic transformers and brushless direct current motors or frequency transformers of two-phase and three-phase motors and the like.

Description

technical field [0001] The invention relates to a half-bridge topology of a switching power supply, in particular to an active soft-switching half-bridge method. Background technique [0002] The traditional half-bridge topology is widely used in power electronic switching power supply products, for example, in electronic fluorescent lamp ballasts, energy-saving lamps and electronic transformers. [0003] When the upper and lower switching tubes of the traditional half-bridge are switched, due to the response time delay of the power electronic switching element itself, and the influence of various harmonics and parasitic parameters inside the product, there is a hazard of half-bridge through-through, which often burns out in an instant Half-bridge power switch tube. [0004] When each power electronic switching element of the half-bridge switches from (OFF) to conduction (ON), the front peak of the conduction current ΔiON and the tail of the switching voltage ΔuoN exist at ...

AI Technical Summary

Problems solved by technology

However, because the effective range of the boundary conditions for forming LLC resonant soft switching is not wide enough, it is easily affected by disturbances such as power fluctuations, load changes, and temperature changes. Once the soft switching fails, the half-bridge power electronic switch enters a vicious cycle of hard switching and is damaged.

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