Research Of High-performance Drive Control Methods For High-speed Motorized Spindles

The high-speed motorized spindle works as the core components of high-speedmachine tools and its drive control performance has a significant impact on the machinetool’s machining quality. However, it is a complex electromechanical system and it isdifficult to carry out high-performance drive control on it. The conventional V/F controlis a kind of steady-state control method and therefore its dynamic performance is notgood, so it is necessary to study high-performance drive control methods for thehigh-speed motorized spindle. Focused on this, the main reasearch work of this paperare as follows:Firstly, the backgroud, the source and the significance of this work is discussed, thetechnology status of high-speed motorized spindle products is briefly stated, theresearch status and developing directions of the drive control of high-speed motorizedspindles are detailedly summarized, and the purpose and contents of this work areillustrated. And then, the the fundamental structure of high-speed motorized spindles isintroduced and its operation principle is analyzed. Finally, the mathematical model ofthe motorized spindle is derived, which shows that the motorized spindle is a high-order,multi-variable, non-linear and strongly coupled electromechanical system, and the drivecontrol system of high-speed motorized spindles is presented.Secondly, the mathematical model of high-speed motorized spindles on differentreference frames is studied, the rotor flux-oriented Vector Control (VC) equations arederived, and the functional block diagram of the high-speed motorized spindle’s VCsystem is proposed. And then, according to the functional block diagram, a simulationmodel of the spindle’s VC system is constructed in Matlab/Simulink, the parameters ofthe type170MD15Y20high-speed motorized spindle in our lab are set into the model.Finally, the control parameters are adjusted and the simulation results are analyzed.Thirdly, the theory evidence and the related methods of Direct Torque Control(DTC) for high-speed motorized spindles is illustrated, based on which the functionalblock diagram of the spindle’s DTC system is proposed. And then, a simulation modelof the spindle’s DTC system is established in Matlab/Simulink, and the parameters ofthe type170MD15Y20high-speed motorized spindle are used in the model. Finally,ajusting of control parameters is completed and the simulation results are analyzed.Finally, the similarity between VC and DTC is deeply investigated and the result reveals that the two different control methods actually share the same controlmechanism. Based on this, a recently proposed innovative control method, calledCombined Vector Control and Direct Torque Control (CVCDTC), is derived andanalyzed. Then, according to the principle of CVCDTC, a functional block diagram ofthe motorized spindle’s CVCDTC system is sketched and the corresponding simulationmodel is constructed in Matlab/Simulink, whose parameters are still set by the type170MD15Y20high-speed motorized spindle. Finally, the CVCDTC control parametersare adjusted and the simulation results are analyzed and compared with VC and DTC.