C. Zöller, M. Vogelsberger, T. Wolbank:
"Influence of parasitic capacitances of IGBT inverter on insulation condition monitoring of traction machines based on current signal transients analysis´";
Talk: IEEE International Energy Conversion Congress and Exposition (ECCE), Raleigh, North Carolina, USA; 09-05-2016 - 09-09-2016; in: "Proceedings of IEEE International Energy Conversion Congress and Exposition (ECCE)", IEEE, 1 (2016), ISBN: 978-9-0758-1524-5; 1 - 9.

Abstract:
At inverter-fed traction drives stray currents due to parasitic capacitances in frequency converters and machine cause high frequency voltage components spreading into all conductive components of the drive system. These hf voltages are harmful and origin from the inverter side through fast switching power semiconductors with high levels of output voltage steepness. Additionally overvoltage at the machine occurs by inverter operation of the machine and is thus stressing the machine insulation system. These effects can lead to a reduction of the machine insulation lifetime due to loss of insulation strength. Thus, insulation condition monitoring systems are necessary to enable a safe and reliable operation of a drive. Insulation condition monitoring of inverter-fed traction drives is implemented in this work by evaluating the transient current response after voltage step excitation. The current measurement is performed using the built-in current transducers of the inverter, normally used for the control of the drive, to save cost and space. Insulation degradation usually is a slowly developing process, at which the parasitic capacitances of the winding system change and thus also the transient current response. However, influences from the inverter capacitances cannot be neglected and thus the influence of the parasitic capacitances located in the inverter on the proposed insulation condition monitoring is investigated.

Insulation, Capacitance, Inverters, Transient analysis,

http://dx.doi.org/10.1109/EPE.2016.7695580

http://publik.tuwien.ac.at/files/publik_257078.pdf