Self-commutating Low-speed Reluctance Motor And Its Control Strategy

This dissertation presents variable frequency speed control strategies for a type of low speed and high torque motor- self-commutating low speed reluctance motor (SCLRM) with novel structure and principle. In stead of any gearbox, SCLRM consists of a traditional VR low speed synchronous motor combined with a static converter composed only of six diodes. For this reason, SCLRM not only inherits the advantages of simple structure and techniques from the traditional VR low speed synchronous motor, but also overcomes its limitation of lower torque capability, which breaks a new approach to the research of low speed and high torque motors for direct drive applications. In this dissertation, systematic theoretical analysis and experimental study are carried out on the operation principle, steady-state performance characteristics and variable frequency speed controlling system for this type motor.On the basis of introducing the motor structure, the self-exciting converting principle of SCLRM under three-phase AC supple is described, and the mathematical model of SCLRM is established. This dissertation presents twodifferent variable frequency speed control strategies for SCLRM- V/f variablefrequency speed control strategies realized SVPWM and current-following variable frequency speed control strategies with delay-loop control.The system simulation model is implemented in MATLAB. The steady-state simulation performance of SCLRM in both self-exciting operation mode and inverter feeding mode are studied, and the effect on the steady-state performance by these several driving modes are also simulated.The motor speed driving system use DSP as controller and use these control strategies presented in this thesis. The experimental results of the sample machine shows that these control strategies for SCLRM is feasible. The experimental results and the simulation results are well coincided, which accounts for the sufficient accuracy of the simulation model proposed in this dissertation.