The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor an...The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.展开更多
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
文摘The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.
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.
