Optimal design of a three-phase AFPM for in-wheel electrical traction

Abstract

Abstract-Sinusoidally fed permanent magnet synchronous motors (PMSM) fulfill the special features required for traction motors to be applied in electric vehicles (EV). Among them, axial flux permanent magnet (AFPM) synchronous motors are especially suited for in-wheel applications. Electric motors used in such applications must meet two main requirements, i.e. high power density and fault tolerance. This paper deals with the optimal design of an AFPM for in-wheel applications used to drive an electrical scooter. The single-objective optimization process carried out in this paper is based on designing the AFPM to obtain an optimized power density while ensuring appropriate fault tolerance requirements. For this purpose a set of analytical equations are applied to obtain the geometrical, electric and mechanical parameters of the optimized AFPM and several design restrictions are applied to ensure fault tolerance capability. The optimization process is based on a genetic algorithm and two more constrained nonlinear optimization algorithms in which the objective function is the power density. Comparisons with available data found in the technical bibliography show the appropriateness of the approach developed in this work.

Optimal Design of Axial Flux Permanent Magnet Motors for Ship RIM-Driven Thruster

“…The torque ripple developed by the machine was limited to 10% to reduce mechanical vibration on output performance. In addition, trapezoidal magnets were used because this geometry favors a minimal torque ripple in AFPM machines [46].…”

Axial Flux Permanent Magnet Synchronous Generators for Pico Hydropower Application: A Parametrical Study

“…The general-purpose sizing equation considered in this paper, allows to evaluate the P out as a function of the AFPMGS construction parameters (rotor; stator; PM; windings) as shown in Equation (11) [48,49]. The procedure for determining the different constructional parameters of the AFPMGS according to the desired P out is shown in Figure 2.…”

“…• the slot fill factor, f r , assumed 0.7 for the easy manufacture of the windings and 1 to maximize the induced voltage on the coils and the magnetic flux produced; • the ratio between internal and outer diameter, λ of value 0.37, 0.58, 0.63, 0.70 typical values for industrial use [43,49,[51][52][53]; • the thickness of the air-gap, g of 0.5 and 1 mm values used in industry [48] that limit the increase in air-gap reluctance and considers the manufacturing difficulties of a small machine increasing the ease of assembly and maintenance.…”

“…• the thickness of the air-gap, g of 0.5 and 1 mm values used in industry [48] that limit the increase in air-gap reluctance and considers the manufacturing difficulties of a small machine increasing the ease of assembly and maintenance.…”