A non-intrusive method for friction and windage losses estimation in induction motors

Abstract

In the in-service induction motors (IMs), friction and windage losses (FWL) value should be determined non-intrusively. Hence, in the in-service IMs, instead of measuring FWL, empirical equations are used to estimate FWL value. A novel technique is proposed for estimating the FWL value in low-voltage three-phase IMs based on obtained data from applying the no-load test on 425 simulated IMs in the MATLAB software. The simulated IMs are 380 V, 50 Hz, with different numbers of poles in the power range of 0.37–400 kW. The FWL value for simulated IMs is calculated based on the IEEE 112 standard and by applying the no-load test. Then, based on the dispersion of the obtained data from the no-load test and using non-linear regression, according to the number of IM poles for each number of poles, a third-degree equation for FWL estimation is fitted to the test data. The proposed method to estimate the FWL value only needs the nominal output power listed on the IM nameplate. Also, unlike existing empirical relationships, the proposed approach estimates the FWL value for IMs with high accuracy and non-intrusively. The effectiveness of the suggested technique is confirmed by simulation and practical results.