Research on Wide Input Voltage Range DC/DC Converter
|School||Nanjing University of Aeronautics and Astronautics|
|Course||Power Electronics and Power Drives|
|Keywords||high-speed permanent magnet generating system DC/DC power converter Interleaved phase control cycle-by-cycle current-limit|
High-speed motor has a wide application prospect in the fields like aerospace, high-speedmanufacturing, centrifugal pumps, compressors, flywheel energy storage, medical equipments and soon. Permanent magnet synchronous generator (PMSG) possesses a simple, firm structure and highreliability, and it also has a strong ability in fault tolerance. However, it is difficult to adjust themagnetic field to control the output voltage for PMSG. In order to simplify the power supply systemand improve the reliability of power supply system, designing a power converter for high speedpermanent magnet generator system is needed. The power converter can meet the requirement ofproviding stable28.5V DC voltage for the system. In this paper, the design of power converter of highspeed permanent magnet generator system is deeply studied.Based on the design requirements of wide input range, high power density, high input and outputcharacteristics, High efficiency, the interleaved Buck converter circuit is selected as the topology.Principle of interleaving Technology is studied. Why parallel converter selects interleaved parallelcontrol is analyzed and the Mathematical analysis of current ripple of interleaved parallel converter ismaked. The converter power losses are analyzed and to solve the problem of low light load efficiencydiscontinuous conduction mode and phase control are used.Based on the technical requirements of power converter, the parameters of main circuit isdesigned. The small signal model of the converter is established and the control loops are designed forthe analysis of system and design of control circuit. The power converter is controled with two kindsof control schemes, namely, analog control and digital control. The hardware circuits and softwareprogram of the two control schemes are designed. UCC28070is used as the control chip in analogcontrol circuit, and analog control is more visual. Digital control is implemented by dsPIC30F2023.The hardware circuit of digital control is simple and signal processing are realized by software whichcan easily achieve cycle-by-cycle current limiting control and phase control.Finally, on the basis of theoretical analyses, two sets of experimental prototype are designed andrelated researches are studied for the two kinds of control scheme. The experimental waveforms areanalyzed and the efficiencies in two kinds of control schemes are compared. The rationality andcorrectness of the design are verified by the experimental results. The value of research and design arealso proved.