Analysis of the Voltage Distribution in a Motor Stator Winding Subjected to Steep-Fronted Surge Voltages by Means of a Multiconductor Lossy Transmission Line Model

Abstract

In this paper, the effect of steep-fronted voltage waveshapes infringing on a pulse-width-modulated (PWM) inverter fed induction motor is studied. The system, composed of a feeder cable and a stator winding, is modeled and simulated by using multiconductor transmission line theory in order to predict the voltage distribution among the coils of the stator winding. A recently developed time-domain equivalent circuit is used; it allows one to correctly describe the dielectric losses and the skin-effect in the conductors. The relationship among the voltage distribution inside the electrical insulation and parameters like the rise time of the applied voltage, the cable length, and the distributed losses is deeply discussed. Good agreement has been found among experimental and numerical results

Study on voltage distribution in windings of an inverter-fed traction motor

“…The same results were achieved by L. Gubbala and G. Suresh utilizing equivalent circuits [8,9]. The transmission line theory is used to analyze voltage distribution in motor windings by J. L. Guardao and C. Petrarca [10,11] and the results indicate that voltage distribution relates to the rise time of pulse and the construction parameter of windings, and the highest turn-to-turn stress is located across the last turn of the first coil. A. Narang [12] thinks that 70-120% of the pulse voltage is located across the first coil, but the highest turn-to-turn stress is not on the last turn for all inverter-fed motors -it depends on the turn number of windings and motor construction.…”

“…(12) is derived from Eqs. (10) and (11) and voltage distribution in windings is given by solving Eq. (12):…”

An Improved Methodological Approach for Denoising of Partial Discharge Data by the Wavelet Transform

“…Further activity is directed towards the definition of the Performance Fingerprint, which could be improved by adding new performance parameters, such as the Mean Square Error (mse), or by giving different weights to those already defined. Last but not least, great effort will be dedicated to the exploitation of the wide potentialities of wavelets in PD measurements as for in the case of Partial Discharges in winding systems [25] which could be studied and identified with the help of a multiconductor transmission line model [26,27] in conjunction with the Wavelet Transform.…”

Simulation of the Bearing Voltage in an Inverter-Fed Induction Motor by a Full Three Phase Multi Conductor Transmission Line Model

“…Other more accurate approaches [18,19] adopt a multiconductor transmission lines (MTL) model which allows to take into account the spatial distribution of the voltage inside the system, but are not intended for providing information on the bearing currents. For this reason, based on an MTL model [20] which takes into consideration also the frequency dependent joule losses, the authors have developed a MTL model of the motor winding, able to predict the voltages across the rotor shaft and to estimate the currents flowing through the bearings when the machine is fed by a single-phase ramp voltage with variable slew rate [21,22].…”