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Fuzzy Adaptive Command Filtering Control Of Asynchronous Motor For Electric Vehicles

Posted on:2016-06-26Degree:MasterType:Thesis
Country:ChinaCandidate:J P LiuFull Text:PDF
GTID:2132330479992155Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
In recent years, the environmental pollution and energy crisis have become very serious problems. The electric vehicles are the feasible path to solve the problems of the environment and energy. The electric vehicle drive system which is regarded as one of the core components of the vehicle can influence the overall performances of the electric vehicle. The control strategy of drive motor restricts the development of the electric vehicles seriously. According to the current of the driving motor, the electric vehicle drive system can be divided into the DC drive system and the AC drive system. Induction motors which have the advantages of the simple structure, excellent performance, low cost and convenient maintenance has been widely used in the electric vehicle driving systems. However, induction motors is a strongly coupled nonlinear system. In the process of the operation, because of the influences of the environmental factors such as temperature, there are time varying parameters and lots of disturbances in the control system. It should be pointed out that in the classical control methods the influences of the iron losses are not considered. All of those factors make that the traditional induction motors control systems can not meet the actual needs. So the research of the new control strategy is very importance.In order to solve the problems of the classical control method of induction motors, the command filter backstepping technology is used to design the fuzzy adaptive controller for the dynamic model of the induction motors including iron losses. The controller can overcome the influences of the iron losses and the time varying parameters in the systems and guarantee the high quality of the system.First, the background and significance of the research are introduced. The developments of the induction motors control strategies are analyzed and the present situations of the advanced control strategies are introduced.Second, the adaptive fuzzy control is proposed for a class of single input single output strict feedback nonlinear systems. During the design process, backstepping technology is used to construct adaptive fuzzy controller for the systems and the command filters are used to eliminate the influence of the “explosion of complexity”. The fuzzy logic systems with the adaptive learning abilities are used to approximate the unknown nonlinear functions in the systems. The Lyapunov method is employed to analyze the stability of the closed loop system. The proposed method guarantees the boundedness of all the signals in the resulting closed-loop system and gains the good tracking performances.Third, by building the dynamic model of induction motors including iron losses, the backstepping technology can be used in this model. With the ability of the fuzzy adaptive control method to approximate the unknown functions, the influences of the parameter variations and load disturbance can be overcame. Lyapunov method is used to analysis the stability of the system. The simulation experiments illustrate the effectiveness of the proposed control scheme.Fourth, for the dynamic model of induction motors including iron losses, the command filter backstepping technology is used to design the new fuzzy adaptive speed controller. It should be noticed that the proposed nonlinear adaptive controller has a simple structure and less adaptive parameters. The controller can eliminate the influence of the unknown system parameters and keep a strong robustness. In the Simulink environment, the model of the induction motors including iron losses is built and the simulation results demonstrate the effectiveness of the designed programs.
Keywords/Search Tags:Electric vehicle, Induction motor, Backstepping, Fuzzy logic system, Adaptive control
PDF Full Text Request
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