SRM Design Optimization using OptiNet

The design of Switched Reluctance Motors (SRM) is a complex optimization problem involving a large number of geometrical and electrical parameters. In practice, this can be a challenging task involving a large number of iterations and a long design cycle.

The example presented here demonstrates how OptiNet searches for the improved design of a 8/6 SRM to maximize the torque generated while conforming to manufacturing and operating constraints.

Results

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Variables: The geometry of the motor is defined based on the parameters shown in this figure:

• Pole angles (ßr , ßs )
• Pole heights (Hr , Hs )
• Back iron depth

The objective is to maximize the average torque.

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The initial, minimum and maximum values of each variable are entered. The user has the ability to vary the parameters as continuous or discreet variables.

Figure: OptiNet Variables tab with the parameter values as specified in this example.

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The objective is to maximize the average torque on the rotor while running at a peak current of 14.5 amps.

Figure: OptiNet Objectives tab.

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In this example, there is a constraint that the average torque on the rotor must be greater than 27.0 Nm.

Figure: OptiNet Constraints tab.

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After 13 hours, OptiNet has evaluated the design objectives and constraints against over one hundred thirty different SRM designs (as defined by the tolerances on each variable), represented here by each point on the solution index.

	Initial	Final
βr	16 degrees	18.92 degrees
βs	11.5 degrees	11.93 degrees
Hr	18.0 mm	18.92 mm
Hs	25.0 mm	26.16 mm
Avg. Torque	33.19 Nm	35.16 Nm