A Study of the Pulse Propagation Behavior in a Large Turbo Generator

Partial Discharges Monitoring for Electric Machines Diagnosis: A Review

“…Another reason for performing the test in low frequency is that, depending on the location of the sensor relative to the PD source, the high-frequency components of the PD signal induced by the external high voltage source are likely to be attenuated. Therefore, the greater the detection frequency range, the greater the PD detection accuracy [27][28][29][30][31].…”

“…In the offline tests of [28,44], PD pulses were applied in different regions of the stator winding of a 15 kV turbo generator and a 12.5 kV induction motor, respectively. For all locations, the injected pulses were measured with different magnitudes, depending on the coupler configuration used.…”

“…It was also observed that the pulse peak measured by the sensor is more attenuated as the injected pulse is applied further away from the measurement point. Furthermore, the study of [28] draws attention to the effect of the inductive and capacitive couplings between adjacent coils, where the pulse propagates differently for low-and high-frequency modes (or slow and fast modes). Figure 17 presents a schematic of the path taken by the injected pulse for the high-and low-frequency components of a typical winding.…”