Research On 2kW Programmable Dc Source Of Shifted-phase Full-bridge

Programmable DC power supplies are widely used in aerospace and satellite test systems,semiconductor processing and aging systems,new energy research and development test systems and other occasions.By investigating and summarizing the existing high-power(>1 k W)programmable DC power supplies products on the market,it is found that the products of instrument power supply manufacturers in Europe,the United States,Japan and other countries occupy a large number of intermediate and advanced products markets.Domestic instrument power supply manufacturers who joined this field late are coupled with insufficient R&D(research and development)investment and weak R&D strength.In other words,products of domestic manufacturers are still not competitive in the intermediate and advanced products markets.Therefore,in-depth research on programmable DC power supplies is of great significance to the localization of high-power programmable DC power supplies in the intermediate and advanced products.As the topology of the DC-DC converter,PWM full-bridge circuit which could result in lower efficiency is adopted in the most high-power programmable DC power supplies circuits.However,the application of soft-switching technology to the programmable DC power supply can improve efficiency and optimize output voltage ripple and other indicators.So the boost active power factor correction converter(AC-DC)and ZVS PWM phase-shifted full-bridge converter(DC-DC)can be used as the two-stage topology of the programmable DC power supplies.An universal programmable DC power supply prototype for aerospace which has a maximum power output capacity of 2 k W with output range of 0 V～60 V/0 A～34 A is designed.The working principle of boost active power factor correction converter is analyzed,and the average current control strategy of inductor current continuous mode is selected.In order to design the power circuit parameters and controller parameters,the small signal model is established according to working principle.In addition,the working principle of the Tr-Lag-TC ZVS PWM phase-shifted full-bridge converter is also analyzed.On the basis of the working sequence diagram of each mode,the operating state of the phase-shifted full-bridge converter is analyzed in stages.Considering the loss of duty cycle,the small-signal model of the phase-shifted full-bridge converter can be derived from the small-signal model of the buck converter.The power circuit parameters and the controller parameters are designed according to the constant voltage mode and the constant current mode respectively.The realization of low output voltage ripple,high efficiency,wide output range and control of programmable DC power supply with wide operation range is explored.On the basis of analyzing the fundamental mechanism of achieving each index,target indicators are improved by adopting a variety of unconventional power supply design methods and means.After simulating the boost active power factor correction converter and the ZVS PWM phase-shifted full-bridge converter separately in simulation software,joint simulations are carried out to verify that two-stage circuits can work normally under dynamic and steady-state conditions.Finally,a hardware experiment platform containing two circuits is completed,which is tested and debugged to meet various test indicators.