Do Motors With Identical Nameplates Have Identical High Frequency Parameters?

Electric motors with random wound stator windings with identical nameplate values do not have identical high frequency values, even when consecutively produced in one single batch. For this, eight motors with identical nameplates (seven from one single batch and consecutive serial numbers) were measured using a Hioki RLC measuring device and fitted to a model. The variation in behavior was observed in the raw measurement as well as in the fitted parameters. It was found that the parameters are normally distributed and show similar variation as the raw data. The variation observed was not only in between motors but also inside one motor causing asymmetry in between the three phases of one motor. In order to make high frequency models more widely applicable for mass-produced electrical motors, a large measurement campaign is required to accurately map the parameters and their variation. This will allow future simulations using statistical values e.g. mean and standard deviation allowing conclusions to be drawn for a motor type rather than one particular case.