Active thermal control for delaying maintenance of power electronics converters

Several studies have reported about power semiconductors and capacitors being the most sensitive components in power converters. The lifetime of these devices is associated with the mission profile and the resulting temperature profile. For preventing failures, it is of interest to estimate the Remaining Useful Lifetime(RUL) and several condition monitoring methods have been proposed for this purpose. Moreover, modular power converters consist of a high number of components and methods have been proposed to reduce the thermal stress and therefore extend the lifetime of a system with software, referred to as active thermal control. For power converters with limited accessibility, the RUL detected by the condition monitoring system may not fit to the scheduled maintenance of the system and devices may still have a significant RUL when their replacement is scheduled. Therefore, this work proposes to control the stress of the most deteriorated components in the system such that the failure probability of multiple building blocks is equalized when the next maintenance is scheduled. Moreover, this concept is proposed to extend the time to the next maintenance and reduce the number of maintenance instances without affecting the mean lifetime of the system.