Power Supply For High Power Server Based On PI~λD~μ

With the development of society,the information level of human society is getting higher and higher,and as the carrier of information data server,its security problem has been widely concerned by people.According to the relevant survey data shows that 80%of the failures caused by server paralysis and 45%of the user terminal data loss and error are closely related to the quality of the user’s power supply,so people have never stopped the research and design of higher performance server power supply.The server power supply(PSU)designed in this topic uses AC power supply,and the design of the power supply uses a two-stage converter structure,which is the pre-stage Boost_PFC circuit and the post-stage phase-shifting full bridge circuit.In order to reduce the operating load of the digital chip in the fractional PIλDμ controller,the Boost PFC circuit of the former stage is controlled by UCC2818AD analog chip.The control mode is average current control.The small signal model of Boost PFC circuit is analyzed and verified by simulation.Through simulation and measured waveform,it is proved that the Boost_PFC circuit can effectively reduce the harmonic distortion of input current,and realize the effective tracking of current to voltage,and improve the power factor of the device.The back-end DC-DC converter adopts the phase-shifted full-bridge(PSFB)topology.The small-signal working principle of the phase-shifted full-bridge(PSFB)power stage circuit is analyzed by comparing the small-signal working principle of BUCK circuit.Synchronous fullwave rectifier is adopted in the secondary side output rectifier to reduce the on-on loss of the power device and improve the conversion efficiency of the power supply.Through the analysis found that the phase shift full bridge(PSFB)power level circuit using voltage type PID control its dynamic response ability is weak,in order to improve this situation,this design introduces the fractional PIλDμ controller to replace the traditional PID controller,through the MATLAB simulation results comparison,compared with the traditional PID controller,PIλDμ controller control phase shift full bridge converter output ripple is smaller,output dynamic response ability is stronger and output hold time is longer,more suitable for the server power supply.After theoretical analysis and simulation calculation,this paper designs a high-power server power supply with Boost_PFC circuit before and fractional PIλDμ control phase shift full bridge(PSFB)circuit.The dynamic response is fast,the output voltage ripple is small and the full load power off holding time is more than 20ms,which has achieved the design goal.