Verification of actual mechanical losses on the rotor of induction machine

The subject of this paper is evaluating and comparing of the measured mechanical losses with equation for mechanical losses calculation. The electric machines have numerous sources of losses which are converted into the heat. These losses heat up the machine and have an impact on the total efficiency. There is an effort to reduce the losses to a minimum value without increasing the size and the weight of the machines. In this paper, two induction machines are compared by using analytical formulas for determining the mechanical losses. Thereafter the measured values are compared with existing formulas and their accuracy is evaluated. Furthermore the overall deviance of the result in the calculation and design of the machine is discussed. The percentage of the total losses and the influence on the efficiency of the machine is used to demonstrate the effect of the error of the measurement.