Research On Fractional Order Controllers For Permanent Magnet Synchronous Motor Speed Control

As a linear optimal control, PID control has been widely used in industrial processcontrol. PID controller based on object model design, method standard mature, simple andpractical, it is the root cause can be widely applied. However, the existing models of thecontrol object is often to ignore the time-varying, nonlinear factors and simplified to get. Forhigh-performance control system, these neglected factors will directly affect the systemperformance. Looking forward to developing the merit of the classic PID controllers andovercoming the flaw of the classic PID controllers to meet the high performance speed controlneeds. This paper attempts to use the fractional calculus theory to design a PIDcontroller-fractional PIλDμcontroller. Research focus on three aspects of the fractional ordertypical links features, fractional order speed control system performances and the fractionalorder speed control system experimental study.1. In-depth analysis of these typical aspects of the fractional integrator, the fractionaldifferential link, the fractional proportional integral link, the fractional proportion differentiallinks and fractional order proportional integral derivative link by frequency characteristics andstep responses. The characteristics of fractional order typical links are different from integerorder typical links, may expand the space for the desired frequency characteristics in thehigh-performance system design.2. Replaced the integral order controller by fractional order controller in traditional speedcontrol system, in-depth study of the properties of fractional order speed control system bytheoretical analysis and simulation, which include stabilization, rapidity and robustness.Proved the stabilization of fractional order speed control system. Simulation research hasbeen used to compare the step response performance of fractional order controller and integralorder controller in speed control system, and obtain the conclusion of the rapidity of fractionalorder speed control system is better than integral order speed control system. Also gives theconditions of the fractional order speed control system to meet the robustness.3. Proposed a fractional order proportional integral controller, fractional orderproportional derivative controller and fractional order [proportional derivative] controller onthe basis of theoretical studies, and applied to a permanent magnet synchronous motor(PMSM) speed control. In the same conditions, the simulation and experimental study areimplemented to validate the effectiveness and advantages of the designed fractional ordercontrollers by comparing with the optimized integer order controller in the real-time PMSMservo system. Simulation and experimental show that the designed fractional order controllers outperform the traditional optimal integer order controller in transient response, trackingperformance, load disturbance rejection, robustness to the loop gain variations and theultra-low speed tracking performance with severe nonlinear effects, and also have a goodenergy-saving effect, suitable for the speed control system demanding higher performancerequirements or lower the energy consumption. The above experimental results andtheoretical conclusions close. Fractional order controllers can improve the controlperformance of the PMSM speed control system, enhanced load disturbance rejectioncapability of the system, reduce energy consumption. Suitable for speed control system indemand of higher control performance and decreasing energy consume. Research resultprovide a theoretical basis and practical application basis for application of fractional ordercontroller in PMSM speed control system.