Research On Sliding Mode Variable Structure Control System Of Hybrid Motor

With gradual maturity of vector control technology, the vectorcontrol system of PMSM, based on the control strategy of variablestructure, is becoming an important research direction. In the process ofthe motor running at full speed, due to the internal change of parametersand external interference, it is difficult for PI and other traditional controlmethods to ensure the system keep in good dynamic and staticperformance, a vector control method for motor, based on sliding modevariable structure of self-adaptive current and speed, was presented in thispaper, and carried out a research about some issues focused on the slidingmode variable structure, such as chattering weakening、the systematicrobustness to external interference and etc.Firstly, the background and development trends of hybridautomobile was introduced, sketched the systematic component of it, andanalyzed the studying significance of its intelligent controller.Then, an detailed analysis of the mathematical model of PMSM inthree kinds of different coordinate systems, and discussed the controlstrategy of PMSM, cited four kinds of current control method ofpermanent magnet synchronous motor. Following the presentation of thecontrol theory of sliding mode variable structure, including itsdevelopment、principle、and characteristics, some commonly used forweakening chattering methods of sliding mode variable structure aredescribed in detail. In the course of this research, using the method ofintegral sliding surface reduces the chattering to enhance the dynamicperformance of the system. In the view of the problem of uncertaintybrought by external interference, uncertainties from it were estimated,using a control method combined self-adaptive and sliding mode variablestructure is to self-tuning to the parameters of controllers. By changingthe estimated coefficients of uncertainties, the control system based onsliding mode variable structure of current and speed was designed. Themethod, on the one hand, overcomes some difficulties from the conventional PI control method, such as the self-tuning difficulty of itsparameter、sensitivity of fixed PI parameters to the changes of motorparameters, speed and load、poor robustness, and etc; on the other hand,not only ensures the stability of the system, but it also improvessystematic robustness.Then again, two kinds of simulation model of permanent magnetsynchronous motor control system—one is the combination of traditionalPI and vector control, another is combination of sliding mode variablestructure and vector control, were built in the software of Matlab7.5.0/simulink. And replacing disturbed load signal with several step signal isto verify the operating performance of permanent magnet synchronousmotor under two different control strategies, which makes the comparisonand analysis of simulation results.Finally, the hardware and software of PMSM controller used inhybrid automobile was designed and conducted some experimentalresearch. The related circuit diagram, based on chip-DSPTMS320F28335as its core controller, was design. Meanwhile, theportrayed flow chart of software, with programming and burning of CCSsoftware, which verifies the feasibility and effectiveness of controlstrategy adopted in this paper, on the compr-ehensive experimentalplatform of DSP-motor.