Direct liquid cooling of power modules in converters for the wind industry

Today's wind turbines converters are being designed for a lifetime of 15-20 years corresponding to 150-180.000 hours of service which is 10-20 times the lifetime required for typical automotive applications and 5-10 times the requirement in industrial applications. When designing for reliability a comprehensive understanding of the relevant failure mechanisms and mission profiles for the specific application is essential. Because high reliability of power electronics is directly linked to temperature it is clear that efficient cooling is a must for an optimum power module design that will be able to withstand the loads occurring during the 15-20 years of service life of the wind turbine. In this paper it is shown that the ShowerPower (R) cooling technology, applied on standard flat baseplate power modules, is well suited for use in wind power applications, obtaining extraordinary thermal properties, reducing size and weight as well as cost for the converters.