Standard square wave soft switch two-way current conversion circuit and its application

The invention discloses a quasi-square wave soft-switching two-way variable current circuit and the applications thereof. The quasi-square wave soft-switching two-way variable current circuit comprises a voltage-typed converter bridge and an auxiliary current switching circuit, wherein, the voltage-typed converter bridge consists of four switching tubes and continuing flow diodes which are connected in parallel with each switching tube; the auxiliary current switching circuit consists of two current switching inductors and an energy storage inductor which are connected in a star shape, the end points of the two current switching inductors are respectively connected with the middle points of two bridge arms of the voltage-typed converter bridge, the end point of the energy storage conductor is a current end and the two ends of the bridge arms of the voltage-typed converter bridge are the voltage end. The circuit works through the alternative functioning of two bridge arms to realize the connection of the switch at zero voltage and the disconnection of the continuing flow diode with zero current. Compared with the traditional hard switch circuit, the quasi-square wave soft-switching two-way variable current circuit reduces the losses in the switch connection and in the diode disconnection and can be applicable to two-way DC/DC transformer, single-phase or multiphase DC/AC transformer and in particular to the increase of the current transforming efficiency of the current transformer with comparatively high power.