The Research Of Electric Bicycle Drive & Control System Based On SRM

The thesis firstly presents the developing status of SRM and indirect rator position detection, the configuration and characteristic of SRM. Then, in allusion to the requirements of drive motor used for electrical bicycle, the thesis accomplishes the parameters selection and the basic configuration design for SRM, the power converter topology selection, the power switch selection and the calculation of power loss.The thesis design task mostly includes two parts, one is the design for drive&control integrative system, the other is the design for rator position detection.Drive&control integrative system includes the circuits with the functions of system power supply, power drive, position signal input, rotate speed feedback F/V conversion, close loop control circuit, PWM wave generation, current chopping signal comparison, lacking voltage protection and current protection. Double closed loops control uses PI regulating method. The MCU is used to judge rotator position information, synthesize various protection signals and commanded information, and speed condition, then it gives the phase on-off signal and current chopping signal limited value at low speed. PWM signal, phase on-off signal, current chopping signal and current protection signal are logically synthesized to produce switch signal to control the power MOSFET.Rator positon detector design includes direct detection and indirect detection methods. According to special structure of outer rotor motor, the thesis designs a derict detection method which using photoelectric sensor. Then, from the analysis of relation between phase inductance and rotor positon, the thesis gives the model of linear phase inductance and provides a conception which using non-excitation phase inductance detection. The inductance resonance circuit, current concatenation circuit and DSP system are given in the hardware design, and also some flow chart given in the software design.Finally, the debugging research which can verify the functions is implemented on the drive&control system.