| Switched Reluctance Drive(SRD) system, as an electron-mechanical product, is a new kind of variable-speed drives, which has been developed from 1980s. It has advantages of simple structure, higher reliability, easy regulating of speed, flexible controllability and so on, and, therefore, it has wide applications. Since high saturation phenomenon occurs in the magnetic circuit of Switched Reluctance Motor (SRM) which is the main part of the SRD system, the inductance is a nonlinear element, and it is quite a difficult to calculate the parameter accurately and to set up the model for SRD. The purpose of this thesis is to recommend a convenient powerful computation program and a simulation platform of SRD including SRM, power electronic circuit, control strategy for the designers and researchers.The important points in this thesis are summarized as follows:1. Beginning from the original geometric sizes and the material properties of electromagnetic design of SRM, ANSYS , a finite element method business software, is employed to determine the flux linkage functionψ(θ,i). The content contains the procedures how to set up the 2D field model, how to calculate the field, and how to obtain the family of the flux linkage characteristics, taking a 6/4 poles SRM as a prototype example.2. Related modules in the toolbox of MATLAB/Simulink are adopted. The nonlinear mathematic model for SRM is obtained by adding the flux linkage functionψ(θ,i) into the parameter table of the motor module. At the same time, in order to establish SRD simulation model, the power circuit module and controller module as well as the corresponding parameters should be properly selected or rebuilt.3. Dynamic characteristics of different operation states are simulated and analyzed by the nonlinear model of SRD mentioned above. At first, the behavior in motor starting is analyzed, and the start speed cover under the condition of open-loop is also calculated. Then, the influence of turn-on and turn-off angel on phase current is discussed. Finally, stead-state and transient simulations for different operation states such as loading and de-loading, speeding up and down, constant load, under different voltage supplied are investigated respectively.4. The linear model of SRM is introduced to analyze the basic control characteristic of SRM. For the convenience of readers, the related knowledge to application of ANSYS and MALTLAB/Simulink are presented in detail, combining the calculation procedure of a prototype motor.It is worth emphasizing again that the method presented here, based on the two common and reliable softwares, is practically useful and fairly accurate for the design, calculation, dynamic operation analysis, control online and R&D of SRD, considering the effects of nonlinear saturation and beginning from geometric sides of a SRM.
|
PDF Full Text Request