HIGH EFFICIENCY PERMANENT MAGNET MACHINE

摘要

The present invention is a high efficiency permanent magnet machine capable of maintaining high power density. The machine is operable over a wide range of power output. The improved efficiency is due in part to copper wires with a current density lower than traditional designs and larger permanent magnets coupled with a large air gap. In a certain embodiment wide stator teeth are used to provide additional improved efficiency through significantly reducing magnetic saturation resulting in lower current. The machine also has a much smaller torque angle than that in traditional design at rated load and thus has a higher overload handling capability and improved efficiency. In addition, when the machine is used as a motor, an adaptive phase lag compensation scheme helps the sensorless field oriented control (FOC) scheme to perform more accurately.

主权项

1. An electric machine, comprising:
a rotor, the rotor further including:
having a cylindrical shape and a central axis;an axial bore adapted to receive a shaft;an outer circumference adapted to receive a plurality of permanent magnets comprising of permanent magnet material, wherein each permanent magnet has a magnetic flux density between 70 and 95 percent of a residual magnetic flux density of the permanent magnet material; a stator, the stator further including:
having a cylindrical shape and a longitudinal axis;an outer circumference;a plurality of teeth disposed in an equidistant angular relationship, each tooth projecting inwardly toward the longitudinal axis, the teeth creating a discontinuous inner circumference configured to accept the rotor within the stator such that the longitudinal axis of stator is aligned with the central axis of the rotor and the rotor is rotatable within the inner circumference of the stator;a stator slot of predetermined shape and size disposed between each tooth and adapted to receive a predetermined number of strands of conducting material to form an electrical winding around at least one tooth; a predetermined number of poles, whereby the number of poles is directly proportional to an electrical frequency of the electric machine and inversely proportional to a number of required coil windings; and an air gap between the outer circumference of the rotor and the inner circumference of the stator when the rotor is disposed within the stator.