Reliability analysis of a high-efficiency SiC three-phase inverter for motor drive applications

Abstract

Silicon Carbide as an emerging technology offers potential benefits compared to the currently used Silicon. One of these advantages is higher efficiency. If this is targeted, reducing the on-state losses is a possibility to achieve it. Parallel-connecting devices decrease the on-state resistance and therefore reducing the losses. Furthermore, increasing the amount of components introduces an undesired tradeoff between efficiency and reliability. A reliability analysis has been performed on a threephase inverter for motor drive applications rated at 312 kVA. This analysis has shown that the gate voltage stress determines the reliability of the complete system. Nevertheless, decreasing the positive gate-source voltage could increase the reliability of the system approximately 8 times without affecting the efficiency significantly. Moreover, adding redundancy in the system could also increase the mean time to failure approximately 5 times.

Comparative reliability analysis of electric aircraft versions for NASA’s X-57 based on Lz-transform method

“…No further inverter information was found in NASA's literature. Since [10] used the same module in reliability calculations, the adapted failure rate of λ INV = λ inv = 0.0316 y −1 will be used in the later reliability calculations. The value was adapted with the use of provided equations for three CAS300M12BM2 per module instead of the six considered in the study.…”

“…The performance values are defined as P Mm and 0, as each branch needs to be capable of carrying the full motor power P Mm in case of failure of any of the other branches. The practical failure rate was calculated by the formulae and data provided in [10] for one capacitor and three half-bridge modules, equals to λ B6 = 0.0316 y −1 . The same value was used for the X-57 cruise inverter (see Section 3.5).…”

Assessment of Efficiency and Reliability of Wide Band-Gap Based H8 Inverter in Electric Vehicle Applications

“…In the following a different analysis is performed, aiming at quantifying the benefits in terms of lifetime extension of a SiC converter with the same thermal design of an Si one. This question is of industrial interest, because of the possibility to re-use existing thermal designs and the possibility to decrease the maintenance of the products [21,22].…”