Condensation Test: Methodology and Robustness Against it for Power Modules Employed in Railway Application

Inhalt:
The methodology of a condensation test for power modules employed in railway applications is pre-sented. We use a climatic chamber which cycles temperature and humidity at the same time, across two main levels (T=45deg C, RH=85% and T=10deg C, RH=40%), imitating train use conditions, making sure to have condensation of water molecules in the silicone gel. We also explain the importance of an ade-quate pre-humidification time, before the beginning of condensation cycling, ensuring that moisture fully saturates in the silicone gel before the temperature drop. Finally, we show the results of such test for 6.5kV HiPak and 3.3kV LinPak modules, as well as those of an accelerated test with higher humidifica-tion (T=85deg C, RH=85%), which ensure good margin for condensation events.