Effects of coil configuration switching, pole-changing and multi-phase windings on permanent magnet synchronous motors

Abstract

This contribution suggests an approach to determine the optimal design of a Permanent Magnet Synchronous Motor for a given application by calculating the effects of coil configuration switching, pole-changing and multi-phase windings. The impact on the torque-speed-characteristic of a motor is evaluated in a normalized parameter plane, enabling the designer to compare the influences by using criteria like the operating range. Moreover, a way of assessing additional semiconductors is introduced. The effects on an exemplary design are presented in a unified approach. Due to this, promising designs for the example can be identified, which double the reachable torquespeed area to nearly ideal values.

Pole-Transition Control of Variable-Pole Machines Using Harmonic-Plane Decomposition

“…the harmonic planes are independent and each one resembles a three-phase IM. Therefore, we choose to use the Γ −1 -model in (7) and depicted in Fig. 1a [22].…”

“…A subgroup of MPEMs aims to improve the torque-speed capability, power density, efficiency, and/or fault tolerance by using independentlycontrolled stator coils, targeting electric propulsion applications [5]. These have ensued from the development of s.c. dynamic machine-operation machines [6], conventional variable phase-pole machines (VPPMs) with mechanical or electromagnetic switches to reconfigure the stator windings [7], and machines employing pole-phase modulation (PPM) [8], [9] to electrically change the phase-pole configuration (PPC). Notably, a design study of a variable phase-pole induction machine (IM) in [10], shows that the pole-changing capability enables comparable torque densities to a commercial automotive permanent-magnet synchronous machine while operating at higher efficiencies in the high-speed, low-torque region.…”