Research On High-power Low-voltage High-current Switching Power Supply

The technology of soft-switching is the key technologies which is the developmentof DC conversion device to the high-frequency, high power density. In this paper, thephase-shifted full bridge zero voltage switching DC-DC converter is used. When theswitching devices of phase-shifted full bridge ZVS is in the process of opening orshutdown. The voltage of switching device is zero, That is zero voltage switching. In theswitching procession, This switch mode significantly reduces the oscillation of theswitching losses, which can greatly improve the switching frequency, which create theconditions which are miniaturization of the switching power supply and high efficiency.The DC-DC converter of Phase-shifted full bridge ZVS is the main form of largeand medium-power switching power supply, Kind of converter to regulate the outputvoltage by changing the size of the phase-shifting angle of the full-bridge switch drivevoltage The voltage phase of the control pole of the super forearm switch ahead of thecontrol voltage pole of the lagging arm switch And two reverse drive voltage of thesame bridge arm to set the different of dead time, Use transformer leakage inductanceand the resonant inductor and the junction capacitance of switch to finish the resonantprocess Which can achieve zero voltage turn on or off, Staggering the hard switchingstate of the high voltage of the switching devices. So it can Inhibit inductive shutdownvoltage spikes and reduce the tube temperature of capacitive opening. So it can reducethe switching loss and interference.This paper analyze the working principle of the phase-shifted full bridge ZVSDC-DC converter And given the parameters of the main circuit, In this paper, thesystem software includes the design process of the main program,interrupt subroutine,digital modulator and filter subroutine. The paper also gives the system hardwarefunctional block diagram, And some of the hardware circuit are described.Digital phase-shift PWM DC transform device control system is a simple hardwarestructure, It is implemented very easily. Software design are simple and practical arereliable, So it is easy to achieve all design features, The main circuit parameter design iscorrect and reasonable, to meet the design requirements of the actual converter device,which verifies the correctness of the selected program.