Zhenxing Fu - Ann Arbor MI, US Lars Weinschenker - Royal Oak MI, US JingChuan Li - Troy MI, US
International Classification:
H02P 5/00
US Classification:
318139
Abstract:
A method of controlling a brushless direct current motor without a position sensor. The motor includes a plurality phase windings adapted to be energized by an active inverter circuit that synchronously applies drive voltages through a plurality of phases to produce drive currents in the phase windings. Back electromotive force voltages are detected when the inverter circuit is inactive for sensorless detection of motor position.
A stator assembly includes a plurality of stator slots, including a first stator slot defining a slot axis. A plurality of conductors is at least partially positioned in the first stator slot and forms a winding set. The assembly is characterized by uneven conductor lengths and a combination of series and parallel connections in the coil sets of the winding set. The winding set includes at least one coil set with the conductors connected in series and at least one coil set with the conductors connected in parallel. At least one of the conductors extends a first conductor length along the slot axis and at least another of conductors extends a second conductor length along the slot axis. The first conductor length is different from the second conductor length. The assembly results in reduced winding alternating current losses, enhanced motor torque and additional turn count options.
