Loss Segregation Method For Converter-Fed Induction Machines Based On Experimental Testing

In this paper a method for segregating losses of a converter-fed induction motor (IM) is proposed. The method does not require the usage of any special hardware that is not readily available in well equipped laboratories. The loss segregation is based on the separation of fundamental loss components and high-frequency harmonic (HFH) losses induced by the pulse width modulation. The tests are carried out using IE3 rated IM at 45 Hz operation point, that is the international efficiency classification point for converter-fed motors. However, the supply frequency is not limited, and the method can be also used to segregate the losses at different operation points. As a reference the standard segregation of losses procedure with 50 Hz sinusoidal supply is presented. The different loss components of the tested IM are presented and analyzed with carrier frequencies of 2 kHz, 4 kHz and 8 kHz. The results behave as expected and the loss segregation procedure looks promising addition to energy efficiency analysis of converted-fed machines.