Optimization of the design for a switched reluctance drive controlled by trapezoidal shaped currents

Abstract

This papers deals with an original way to optimize the pre-designing of a switched reluctance motor (SRM). The analytic equations are treated to make the complete design depend only on two parameters. Particular attention is paid to high rotational speeds and the hypotheses they induce on the design. The hypothesis of a current control is assumed and the methodology tackles the design problem through the angle of the power electronics constraints.The specific problem set by the trapezoidal current shape is highlighted, as much as the direct constraints induced on the motor shape design. Mechanical and thermal limitations, modeled in function of the main material characteristics are deterministically taken into account. An optimization is finally performed, reducing the losses of the motor in terms of the mere lasting parameter.

Geometry and Topology Optimization of Switched Reluctance Machines: A Review

“…Deterministic optimization methods can also be classified as unconstrained and constrained methods. The constrained methods are considered here since there are usually spatial constraints on the different design parameters of SRMs and electric machines design in general [102].…”

A 100kHz-2kW converter for switched reluctance rnotor used in high speed machining applications

“…Main applications of SRM are flywheels, energy storage and wind turbines, however, this motor technology also finds its interest in high speed machining. The physical constraints which limits the realisation of these very high speed motors are mainly mechanic and thermal [2]. The mechanic constraints deal with the ferromagnetic sheets breaking resistance and vibrations.…”

“…Two prototypes1 of 6/2 type switched reluctance motors were developed. Different works have been performed on real time control, mechanical behaviour, and electromagnetic design and optimisation fields over the last five years [2].…”

“…In this aim, currents have to be closely controlled. The switched reluctance motor technology also induces special current forms at high speeds [2]. Dimensional and physical sizes, phase voltage and currents or magnetic fields are important elements to correctly determine the design of this SRM.…”

“…Both of the above described converters are very often employed, since they are cheap and suitable for low speeds drives [10]. Nevertheless, with very high speeds, converters must be designed to produce a rotating field at the stator, in order to limit iron losses both in the stator and rotor materials [2]. Since losses evacuation are very difficult at the rotor, this additional aspect is of great importance on the global design of the complete device (power electronics, motor and control loop).…”