Measurement of large AC electrical machine stator windings parameters at high frequency

To analyze the propagation of high frequency signals, such as partial discharge, dv/dt, di/dt of PWM inverters in electric machines, it is necessary to determine the stator windings parameters at high frequency. This paper describes an experimental method for measuring the stator windings parameters of AC large electrical machine at high frequency. The method is based on the theory of multi-conductor transmission line (MTL). The experimental results of large turbine generator stator windings in three condition are given: single bar wrapped in aluminum foil without iron core; single bar in an iron core slot; two bars in an iron core slot. Results for the double bars in the slot show that a steep-fronted pulse propagates in stator slot bars of turbine generator with two modes.