Partial discharge detection in power modules

Today, most railway applications use hybrid power modules. These IGBT modules are constituted of several dielectric materials to achieve chip packaging. Due to the presence of high voltage, new phenomena which could be previously ignored for lower voltage ratings have now to be taken into account. This is the case of partial discharges which may appear in this dielectric material stack. Up to now, the only test carried out to detect partial discharges in such modules is the application of a normalised test (IEC270). The proposed test configuration only allows testing of a part of the dielectric insulation. For this reason, we propose and discuss a novel method for determining partial discharges existence in power modules.