Single-phase Permanent-magnet Motor Research Articles

Design, Prototype and Experimental Verification of Single Phase Flux Switching Motor Using Low Cost Magnets

There has an increasing demand for a low cost brushless alternative to the series universal motor and single phase induction motor in domestic appliance and automotive applications. Single phase FSM with field winding has relatively low efficiency and low power factor. This paper tries to investigate a topology of single phase FSM which uses low cost magnet, i.e., Ferrite instead of field winding to provide field excitation. By using field focusing effect, the magnets are properly arranged to provide the required airgap flux. A standard design procedure for the presented FSM is developed. Extensive comparisons to the single phase induction motor, single phase permanent magnet motor and universal motor are made. A prototype with 8/4 pole configuration is fabricated. The experiment results are given and compared to the FEA simulated results. In addition, the electromagnetic vibrations and acoustic noises are also considered and measured which is always seen as the main disadvantage of this kind of motor.

Robust Servo Control of a High Friction Industrial Turbine Gas Valve by Indirectly Using the Standard$mu$-Synthesis Tools

The current mu-synthesis tools are not directly suitable for industrial turbine fuel and water control because they lead to high-order controllers with physically meaningless states. The production valve example here is the Woodward GS6 Turbine Gas Metering Valve that has a single-phase permanent magnet motor coupled by a shaft to an inertia disc and a gas metering shoe with a high level of dry (nonlinear) friction and flow forces. The embedded TI-DSP-2407 processor that runs the position controller in the 1 ms loop rate practically limits the maximum controller order to seven. This paper describes how an industrial seventh-order 2-degrees of freedom (DOF) controller was designed by indirectly using the standard tools available in the mu-Toolbox. Step, limit cycle, and frequency response measurements show that the new design compares favorably well with the standard production controller. However, the key advantages were that the first design downloaded into the controller did not require retuning, the design process was higher level, and the measure of "robustness" was in terms of the physical description of plant uncertainties