A Laplace-Clarke distributed HF model of asynchronous machines

An innovative three-phase distributed model is presented for asynchronous machines operating at high-frequency. The model is useful to study the propagation of surge along the stator windings of the machines that is excited by PWM-inverter source or fault waves that occur in the connected line. The new model is derived from single-phase models traditionally considered in literature. The use of time-space Clarke vectors allow the introduction of mutual coupling between phase winding and the integration of the model extending the methods that had been developed for the single-phase case by substituting real time-space variables with complex functions. A numerical method useful to simulate the distributed model is presented too. This is based on Laplace transformation of the Clarke waves. Finally, the first numerical results, carried out by applying a unitary steep-surge and a standard IEEE wave for insulation test to the obtained equivalent distributed networks, confirm the model validity and permit to underline the required low computational cost of the approach.