Handling High Voltages in E-Mobility

E-mobility has brought many new challenges to car manufacturers, from design and production to the final test of these electric cars. Compared to the traditional 12V grids of legacy cars, the high voltages of the traction batteries of 800+V require new techniques and non-standard, reinforced isolation barriers to guarantee the safe testing of the complete car at the end of the production line. Learn how RECOM was able to provide a unique solution in this case.

At the end of the production line, all functions and components of a car, including the traction batteries in e-mobility solutions, must be tested: so, the customer needed an isolated 24V-to-24V converter delivering 60W. This requirement seems easy, but the big challenge was to withstand a very high voltage of 1,750VAC peak with a frequency of 100kHz applied across the isolation barrier during the test.

While isolation barriers of converters are tested with voltages of 2 to 5kV for a few seconds, applying such a constant, high voltage across the isolation results in degradation, and ultimately breakdown, of the isolation materials. Therefore, the customer could not find a standard converter that was able to meet this requirement.

RECOM’s technical support team took this challenge and found a unique solution. A 30W medical converter meeting the basic electrical input, output, and power requirements was the base for further investigations. This part was designed and approved for the high-isolation requirements in medical applications and RECOM’s team validated in this application with intensive, partial-discharge tests (if you are interested in the technical details of this topic, please read the “BIER” Test article from RECOM).

Finally, the converter passed these tests and was approved for safe operation at a continuous voltage of 1,750VAC across the isolation barrier.

This standard converter can deliver 12V 30W and by connecting the outputs of two converters in series, the customer obtained the 24V 60W needed for this application with the very high reinforced isolation voltage of 5kVAC. In addition, the low profile case of the REM30-W (10.2mm high) meant that the two converters could be mounted easily side-by-side.