Design and evaluation of a converter optimized synchronous reluctance motor drive.

摘要

The Doubly-salient switched reluctance motor (SR) has been found to be a favorable alternative to more conventional PM synchronous and induction machines in converter fed variable-speed drive applications. The fundamental feature of this type drive is that the switched reluctance motor requires only unidirectional current corresponding to a greatly simplified converter topology and switching algorithm. On the other hand, the switched reluctance motor is such a design that only very small portion of the airgap in the motor remains "active" at any moment of torque production with a comparatively high electromagnetic stress on the active materials. It is apparent that any method of ensuring that the other three quarters of the inner circumference of the stator remain "active" will be a very significant step towards relaxing the severe electromagnetic stress on the active materials and reducing the losses of the machine.; A converter optimized synchronous reluctance motor drive is designed and evaluated in this thesis. The motor has a conventional cylindrical, slotted stator and an axially laminated round rotor. The associated converter utilizing IGBT devices and controller based on DSP56000 microprocessor have been built. Since the current waveform of the rotor must be carefully regulated to extract the maximum torque/ampare, this machine is denoted in this thesis as a current regulated synchronous reluctance machine or CRR.; The analysis by the linear and nonlinear models of the CRR motor show that the parameter, {dollar}Delta{dollar}L/{dollar}Deltatheta{dollar}, has been maximized because of the unique machine structure, which results in an improved torque/ampere capability and power density. While improving power density, the CRR motor presented retains the advantages of the SR motor. The number of devices in the converter is minimized due to the fact that the CRR motor is wound into two phases and an uni-directional phase current is utilized.; The experimental CRR motor has been tested in the lab. The tested results are in good agreement with the theoretical predictions. In order to improve the performance of the CRR motor further, iron loss minimization and harmonics elimination are proposed for the future work.