# Design, Modeling and Prototyping a Flat Switched Reluctance Machine for Direct-Drive Systems

• Majid Asgar
• Hossein Torkaman
• Ebrahim Afjei
Original Article

## Abstract

In this paper, a flat-type 24 by 16 SRM, is considered for the application of direct-drive washing machine. Firstly, the structure is introduced and using the nonlinear equivalent circuit, the researchers present a design for the SRM. Then, using the three-dimensional finite element method, the electromagnetic characteristics of the proposed configuration are analyzed to evaluate the motor’s performance. The motor prototype is fabricated and tested experimentally to authenticate the theoretical and simulation analysis, and subsequently to prove the applicability. Finally, the performance of this proposed motor is compared with an SRM that has the same condition. Since a direct drive motor does not require a reduction gear, the drive system can be made simple without harmonic gears, and therefore it can be used in high-precision, more reliable, and low cost appliances.

## Keywords

Machine design Direct drives systems Switched reluctance machine

## List of symbols

$$\beta_{r} (\beta_{s} )$$

(Rotor/stator) pole arc

$$N_{r} (N_{s} )$$

Number of (rotor/stator) pole

$$N_{T}$$

Number of turns per coil

$$N$$

Number of coils per phase

$$q$$

Phase number

$$f$$

Fundamental switching frequency

$$\omega$$

Angular rotor speed

$$T_{a}$$

Average torque

$$P$$

Average power conversion

$$R_{sp} ,l_{sp} ,A_{sp}$$

Stator pole (reluctance/length/surface)

$$R_{sy,} l_{sy} ,\,A_{sy}$$

Stator yoke (reluctance/length/surface)

$$R_{rp} ,l_{rp} ,A_{rp}$$

Rotor pole (reluctance/length/surface)

$$R_{ry} ,l_{ry} ,A_{ry}$$

Rotor yoke (reluctance/length/surface)

$$R_{gap} ,l_{gap} ,A_{gap}$$

Rotor gap (reluctance/length/surface)

$$L_{u}$$

Unaligned inductance

$$L_{a}$$

Aligned inductance

$$\mu_{0}$$

Absolute magnetic permeability

$$\mu_{r}$$

Relative magnetic permeability

$$D_{0}$$

Stator outer diameter

$$D$$

Rotor bore diameter

$$l_{s}$$

Stack length

$$h_{r} (h_{s} )$$

(Rotor/stator) pole height

$$y_{r} (y_{s} )$$

(Rotor/stator) yoke length

$$R$$

Phase resistance per coil

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