Optimal Design of IPM Motors With Different Cooling Systems and Winding Configurations

Abstract

Performance improvement of permanent magnet (PM) motors through optimization techniques has been widely investigated in the literature. Oftentimes the practice of design optimization leads to derivation/interpretation of optimal scaling rules of PM motors for a particular loading condition. This paper demonstrates how these derivations vary with respect to the machine ampere loading and ferrous core saturation level. A parallel sensitivity analysis using a second-order response surface methodology followed by a large-scale design optimization based on evolutionary algorithms are pursued in order to establish the variation of the relationships between the main design parameters and the performance characteristics with respect to the ampere loading and magnetic core saturation levels prevalent in the naturally cooled, fan-cooled, and liquid-cooled machines. For this purpose, a finite-element-based platform with a full account of complex geometry, magnetic core nonlinearities, and stator and rotor losses is used.Four main performance metrics including active material cost, power losses, torque ripple, and rotor PM demagnetization are investigated for two generic industrial PM motors with distributed and concentrated windings with subsequent conclusions drawn based on the results.

Optimal Design of an Interior Permanent Magnet Synchronous Motor with Cobalt Iron Core

“…The convection thermal resistances of the airgap, , and of the machine's surface to the environment through the cooling system, are obtained from (15) and (16). In these, = 2 is the airgap heat transfer surface and = 2 is the electric machine's surface with outer radius R and length L. The heat transfer is described by the thermal equation system (17), where and are the surface and ambient temperatures.…”

Systematically Exploring the Effects of Pole Count on the Performance and Cost Limits of UltraHigh Efficiency Fractional hp Axial Flux PM Machines

“…The total mass of the stator and rotor core are represented with m c , and the copper and magnet mass, with m Cu and m pm , respectively. The mass is calculated in kg and the steel cost per kg is considered as the one-unit reference [18]. This per-unitized method of defining the cost function makes the calculations independent of the impact of using various vendors and currencies, while still including a correct representation of the cost trends needed for design comparison.…”

Exploring the Efficiency and Cost Limits of Fractional hp Axial Flux PM Machine Designs

“…The total mass of the stator and rotor core are represented with m c , and the copper and magnet mass are shown with m Cu and m pm , respectively. The mass is calculated in kg and the steel cost per kg is considered as the one-unit reference [17].…”