| Summary: | 碩士 === 國立宜蘭大學 === 機械與機電工程學系碩士班 === 100 === In recent years, due to the improved living standard, energy saving, and high awareness of environmental protection, the washing machines have been developed on the way to water-saving, energy-saving, noise-free, simple structure, and multifunctional washing process. So, with features such as high efficiency, power density, quick dynamic response, and high starting torque, etc., brushless dc motors are gradually and extensively used in the commercial Direct Drive (DD) washing machines. In this research, a driving technology applying Hall effect position sensors for motors used in DD washing machines is developed. The driving technology uses signals from Hall effect position sensors to do square-wave commutation, sinusoidal commutation, and flux-weakening control (phase advance). The proposed technology is applied to two DD washing machines in the market: one has motor with interior ware earth magnet , while the other has motor with surface ferrite magnet, for dynamic tests. The experimental results demonstrate that the proposed method is feasible and valid. A cost-effective universal control structure is also developed to estimate the quantity of laundry, and to execute washing and spin-dry processes for DD pulsator washing machines. The proposed control structure is implemented and compared with a DD pulsator washing machine available in the market. The experimental result reveals that the dynamic response during washing process is satisfactory. A safe mechanism is introduced and implemented during high speed spin-dry process. The safe mechanism can avoid the failure resulting from charging the DC bus capacitors by the back-EMF voltage.
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