Experimental validation of the dynamic model of a single/two phase induction motor

The unsymmetrical single/two phase induction machine is often used in low-power range and low cost electric drives. The main advantages of this machine - i.e. its uncomplicated structure, machine´s direct voltage supply from a single-phase network supply, the absence of the mechanical commutator thus absence of any phase- switching noise, and the machine´s low-rate of wear - are counterpoised by the low energy efficiency of this machine. A promising way to increase machine´s energy efficiency is the use of an electronically switched, variable capacitance connected to the auxiliary phase of the machine. The optimal control of the electronically switched capacitance is based on the measurements of the phase voltages, phase currents and angular speed at the machine´s shaft and on a dynamic model of the machine implemented on a controller. In the first part of this paper a direct- and quadrature-axis theory-based-model of the unsymmetrical two-phase induction machine is discussed. Within the second part of the paper the results of the theoretical approach are inspected and compared to measurements on a nowadays machine type.