Study On DC Switching Power Supply For Control System Of Bearingless Motor

Due to excellent characteristics of high-efficiency, frictionless, compact mechanicalstructure and so on, bearingless motor is being widely used in high speed rotational machines.Bearingless motor control system is constructed with DSP controller, power driver module,detection circuit, protection circuit etc. In order to guarantee normal function of the system,power supply is required to be high accurate, stable and small volume. Therefore, designinghigh reliable power supply is very important for improving performance of the system.According to the bearingless motor control system, designing a stable and small volumepower supply for DSP controller, power drive module and related circuit is the purpose of thisthesis. Considering the traditional linear power conversion has low accurate, large size andhigh weight, the low-power fly-back switching power supply technique was adopted to designpower module of the system, so as to be high-efficiency, energy-saving, portable andcompact.Requirement of power supply for hardware circuit in bearingless motor control system isanalyzed, and the current high precision switching power supply theory and key technologyare researched, corresponding technical scheme is selected in this thesis. The advantages anddisadvantages of the commonly used converters and the selection principles of switch powerdesigning are given by analyzing common switching power converter topology and principlecharacteristics. On the basis of above work, the design of fly-back switching power supplysystem is completed and detailed design of concrete module circuit is given. The entire designprocess include the design of the main circuit and control circuit, which give the rectifiercircuit, high frequency transformer, the RCD clamp circuit and the UC3842peripheral circuitdesign principles and parameters of the calculation processin in detail. All parts of switchingpower supply are modeled by using simulation software, the effect of model performance ondifferent circuit parameters are analyzed and some parameters are furtherly modify bysimulation results.Finally, according to the design standard of PCB, the switching power experimentalboard is manufactured. During to the analysis of switching power supply performance in testsand experiments, the performance of switching power supply have reached the designrequirement for output power and performance. That is the power supply has goodperformance and its outputs are stable.