Fractional-slot concentrated-coil electric machines are often used in those applications where a number of rotor poles close to the number of stator slots is required. A major criticality of such machines is the occur...Fractional-slot concentrated-coil electric machines are often used in those applications where a number of rotor poles close to the number of stator slots is required. A major criticality of such machines is the occurrence of large air-gap field harmonics due to winding distribution and to slotting effects. Predicting such harmonics analytically with adequate accuracy is a good way to significantly speed-up subsequent investigations, concerning the rotor effects of the field harmonics in terms of rotor losses. This paper proposes different analytical formulations for this purpose, covering the case of a generic number of stator phases and differing by how slotting effects are taken into account. The various approaches proposed are evaluated by comparing analytical results with finite-element analysis computations on a sample machine geometries.展开更多
This paper describes the key issues of high-speed brushless permanent magnet motor design, such as rotor design, stator design, and determination of the main dimensions, and the overall design process was given. In th...This paper describes the key issues of high-speed brushless permanent magnet motor design, such as rotor design, stator design, and determination of the main dimensions, and the overall design process was given. In this paper, a two-pole three-phase high-speed brushless PM （permanent magnet） motor with ratings air-gap length and stator slot number on the motor performance of 7.5 kW, 30,000 rpm is designed, and the effect of the different was analyzed. The results show that larger number of stator slot decreases the rotor loss and the rotor torque ripple. Larger air-gap length decreases the rotor loss.展开更多
文摘Fractional-slot concentrated-coil electric machines are often used in those applications where a number of rotor poles close to the number of stator slots is required. A major criticality of such machines is the occurrence of large air-gap field harmonics due to winding distribution and to slotting effects. Predicting such harmonics analytically with adequate accuracy is a good way to significantly speed-up subsequent investigations, concerning the rotor effects of the field harmonics in terms of rotor losses. This paper proposes different analytical formulations for this purpose, covering the case of a generic number of stator phases and differing by how slotting effects are taken into account. The various approaches proposed are evaluated by comparing analytical results with finite-element analysis computations on a sample machine geometries.
文摘This paper describes the key issues of high-speed brushless permanent magnet motor design, such as rotor design, stator design, and determination of the main dimensions, and the overall design process was given. In this paper, a two-pole three-phase high-speed brushless PM （permanent magnet） motor with ratings air-gap length and stator slot number on the motor performance of 7.5 kW, 30,000 rpm is designed, and the effect of the different was analyzed. The results show that larger number of stator slot decreases the rotor loss and the rotor torque ripple. Larger air-gap length decreases the rotor loss.
