| Permanent magnet synchronous spindle(PMSS)is one of the core components of high-level CNC,which has broad applications in aviation,aerospace,vehicle,precision instrument,mould processing,etc.Independent development of high-speed,high-precision,high-power PMSS will play a crucial role in our own intellectual property right and core competitiveness in the field of high-level CNC.The demand for high speed of high-power PMSS is one of main trends in the development of CNC system,and it has been widely researched by'researchers for many years,however,there are still many theoretical and technical problems to solve.In the dissertation,in order to improve the flux weakening control performance of high-power PMSS driver system,the key technologies of its driver controller,which include field oriented control,current loop control strategy,dead-time compensation algorithm,flux weakening control algorithm,speed control loop strategy,etc.,were studied deeply.The main contributions of this thesis include following issues:? This thesis summarized the development of high-power PMSS driver system.The mathematical model of PMSS was presented,various field oriented control strategies and active disturbance rejection control(ADRC)technology were analyzed in detail.Furthermore,the flux weakening control strategy of PMSS was studied deeply in this dissertation.? The conflict between overshoot and response speed inherent in current PI regulator is difficult to resolve,which will deteriorate system robustness.This thesis adopted steepest tracking-differentiator to arrange transient process for d/q current commands.Simulation and experiment results show that the current values can track the commands more quickly and smoothly.? To solve the problem that in the flux weakening region of surface-mounted PMSS,the oscillation of current in dynamic process and the steady-state error of speed grew with load increasing,an improved leading angle flux weakening control algorithm was proposed.By analyzing the mechanism of the traditional algorithm,the conclusion is that the insufficient voltage output capacity of SVPWM inverter and the voltage close-loop control for the flux weakening control are the main cause.A SVPWM over modulation algorithm with a small mount of computation and the close-loop control based on q axis current error instead of voltage were adopted in the improved algorithm.Experimental results show that the improved leading angle flux weakening control algorithm can decrease the vibration of current in dynamic process and the fluctuation of steady-state speed effectively,mean-while the speed steady-state error was removed,so that the load capacity of PMSS in flux weakening region is enhanced.? To solve the problem that speed PI regulator is susceptible to load-mutation and load-disturbance in flux weakening control,this thesis presented a new speed control scheme which was designed by ADRC technology.Simulation results show that,compared with the traditional speed PI regulator,ADRC technology can improve the anti-disturbance ability of speed regulator.? The proposed methods were implemented based on the high-power PMSS drive system hardware platform constructed by this thesis,and the proto-type is produced.The high speed experiment results of high-power PMSS on the prototype verify the feasibility and effectiveness of the proposed methods... |
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