Derived Functions for MATLAB Non-linear Solvers – an optimal Stator Slot Design Stopgap

In the three-phase squirrel cage induction motor (SCIM), like other rotating electromechanical machines, the active length of the stator windings lies in the slots. The proper dimensioning of the slots is therefore critical to the design of both the windings and the stator core, so as to attain a high performing machine. The preliminary stage of the SCIM design, if well done, facilitates the refinement and optimization stages; serving as a good take-off point for that final state of the art design. The aim of this article isn’t to come up with a novel optimization method for the SCIM, but to provide another way of obtaining an initial stator slot design template, from where proper design refinement/optimization techniques could obtain very good starting values and be facilitated. Therefore, an attempt is being made here to derive relevant design functions that could be fed into the algorithms of various non-linear solvers such as the Genetic Algorithm (GA), to output the main stator slot dimensions for the SCIM. The final designed SCIM obtained from implementing the derived equations, when compared with the appropriate reference datasheets, showed only minor deviations from the expected performance indices – an outcome deemed satisfactory for a preliminary design attempt. These initial dimensions may in practice be subjected to the appropriate refinement. Depending on the target performance requirement of the motor.