Dynamic Induction Machine Model

The PDF and YouTube video linked below describe the defining equations for a dynamic induction machine model implemented in Simulink. There are a number of research publications on this topic however they often lack key pieces of information which the author either decided were so self-evident they need not be included or just neglected due to their familiarity with the subject matter. Something that may be about to happen again. In terms of (academic) research into the design and control of electrical machines the process described here is “very classical” (i.e. more than a few years old). In practice a number of companies known to me use a process similar to this for several types of machine drive, including machines which are not readily linearised.

It is common to include a number of additions to accommodate effects particular to the application. For example in high speed work the frictional heating of the rotor due to wind-age and aerodynamic losses may be included as these are often a strong function of speed. Saturation of the machine iron may be included by parameterising the leakage and mutual inductances as a function of flux or current. Copper and Eddy current losses are relatively easily added and thereafter the thermal effects that these losses create may be included as well.

The final form of the simulation and its scope is limited only by technical necessity, the human resource available to perform the development work and the financial cost the developer is prepared to incur to possess the simulation.

The main cost of developing a simulation for a machine is the validation stages which require physical space, test equipment and human resources to gather the validation data. By comparison the programming of the model including the HR costs of the programming and the cost of the software is often a minor component of a project.

The model, available below, is a standard Clarke-Park abc - dq approach starting with the linearised abc per phase equivalent circuit.

The video is a walk through of how the equations are implemented in Simulink.