Modelling and Test Validation of High Speed Universal Motors Fed via a Triac

The work analyses the universal motor, developing its transient model, where the parameters are derived from the design data; the model takes into account saturation effects and core losses and allows to analyse the performances and waveforms at the load side (torque, speed) and at the terminals (voltage, current). Since the motor is used in low cost household appliances, the power control is often carried out by means of a triac; the model allows to evaluate the distortion effects in different operating conditions. A comparison between the current harmonics and the limits imposed by the Standards is carried out. Test experiments validate the results.