Rotor Flux-Barrier Geometry Design to Reduce Stator Iron Losses in Synchronous IPM Motors Under FW Operations

Analysis of stator iron loss in interior PM machines under open and short-circuit conditions

“…The stator iron loss in IPM machines at high speed has been shown to be affected by the number of stator teeth and the angular spacing between the rotor barriers which determines an effective number of rotor slots [1][2][3][4]. The baseline IPM design has a number of stator teeth per polepair, ns = 18, and an effective number of rotor slots per polepair, nr = 12 and so is described as "ns18nr12".…”

“…References [1][2][3][4] describe the analytical procedure for the estimation of stator iron loss under field-weakening operation with different areas of emphasis. References [1,4] developed a simplified stator teeth eddy-current loss index and used it in a numerical optimization procedure to minimize the stator teeth eddy-current loss under shortcircuit conditions (deep field weakening).…”

“…References [1,4] developed a simplified stator teeth eddy-current loss index and used it in a numerical optimization procedure to minimize the stator teeth eddy-current loss under shortcircuit conditions (deep field weakening). Reference [2] provides an analytical procedure for the stator teeth eddycurrent loss including the effect of the current phase angle and the rotor parameters. Reference [3] analysed the tradeoff between the minimization of the eddy-current loss and torque ripple and discussed the optimal combination of stator and rotor slots.…”

“…The general approach is that lumped magnetic equivalent circuit analysis is used to calculate the rotor magneto-motive force (mmf) [1][2]. The above analytical approaches provide some useful physical insights into the stator iron loss as a function of the stator and rotor design parameters.…”

Modeling and reduction of stator teeth eddy-current losses in IPM machines

“…In [3] the authors derived the major cause of the high harmonic content including the amplification effect due to field-weakening current and presented an analytic design approach to reduce the flux density distortion in the stator teeth. Using an analytic model, the authors in [4], [5], and [6] simulated the tooth flux density for one and two flux barrier IPM machines and highlighted the significant influence of the barrier angle(s) on iron losses. In [7] an index for harmonic eddycurrent losses in IPM machines is derived and a design process is proposed to find the loss optimal flux barrier and magnet dimensions.…”