The electrification of the transportation sector is moving on at a fast pace. All car manufacturers have strong programs to electrify their car fleet to fulfill the demands of society and customers by offering carbon-neutral technologies to bring goods and persons from one location to another. Power electronics technology is, in this evolution, essential and also in a rapid development technology-wise. Some of the introduced technologies are quite mature, and the systems designed must have high reliability as they can be quite complicated from an electrical perspective. Therefore, this article focuses on the reliability of the used power electronic systems applied in electric vehicles (EVs) and hybrid EVs (HEVs). It introduces the reliability requirements and challenges given for the power electronics applied in EV/HEV applications. Then, the advances in power electronic components to address the reliability challenges are introduced as they individually contribute to the overall system reliability. The reliability-oriented design methodology is also discussed, including two examples: an EV onboard charger and the drive train inverter. Finally, an outlook in terms of research opportunities in power electronics reliability related to EV/HEVs is provided. It can be concluded that many topics are already well handled in terms of reliability, but issues related to complete new technology introduction are important to keep the focus on.

Because of the high cost of failure, the reliability performance of power semiconductor devices is becoming a more and more important and stringent factor in many energy conversion applications. Thus, the need for appropriate reliability analysis of the power electronics emerges. Due to its conventional approach, mainly based on failure statistics from the field, the reliability evaluation of the power devices is still a challenging task. In order to address the given problem, a MATLAB based reliability assessment tool has been developed. The Design for Reliability and Robustness (DfR 2) tool allows the user to easily investigate the reliability performance of the power electronic components (or subsystems) under given input mission profiles and operating conditions. The main concept of the tool and its framework are introduced, highlighting the reliability assessment procedure for power semiconductor devices. Finally, a motor drive application is implemented and the reliability performance of the power devices is investigated with the help of the DfR 2 tool, and the resulting reliability metrics are presented.

Power electronics inverters are one of major failure sources in motor drive systems and power devices are one of the main causes of the power electronics inverter failures. Typically, an IGBT module has multiple power devices due to some technical and cost advantages. This kind of configurations could have an asymmetric internal layout, which may lead to different thermal loadings and thereby lifetime difference of the power devices. Therefore, both the power rating and the lifetime of inverters are limited by the most stressed device. However, generally a common data is provided for all devices in the datasheet and this may cause improper design of the inverters in terms of the lifetime and the power rating. In this paper, an effect of an asymmetric layout of IGBT modules on the reliability of motor drive inverters is studied based on a 3-phase motor drive application with a 600 V, 30 A, 3-phase transfer molded IGBT module. The thermal impedances of 6 IGBTs are investigated and its effect on thermal loadings of power devices is studied under the given mission profile. Then, their lifetimes are estimated and compared. Finally, this effect is verified by the experiments.

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Due to the increased cost, and time-demanding approach of conventional reliability improvement procedures, the transition towards model-based reliability assessment of power electronics becomes more and more crucial. Although important steps have been taken in this direction, the resulting lifetime prediction is still subject to different assumptions and uncertainties (e.g. mission profile data, modeling errors, lifetime models, etc.). Thus, this paper aims at investigating and quantifying the impact of the mission profile resolution on the reliability estimation of power IGBT modules and DC-link capacitors. For a 10 kW PV application case study, three mission profile sampling rates (1 minute/data, 30 minutes/data, and 60 minutes/data) are considered and benchmarked, with respect to the predicted lifetime of the power electronic components/system. Finally, an uncertainty analysis is performed for the resulting reliability metrics, and some initial guidelines for mission profile resolution selection are provided.