Kolloquiumsvortrag: “Accelerated Life tests for Electric drives in Aircrafts”
Kaiser Str. 2, Geb.C , Raum "Aquarium"
“Accelerated Life tests for Electric drives in Aircrafts”
The concept behind the More Electric Aircraft (MEA) is the progressive electrification of on-board actuators and services. It is a way to reduce or eliminate the dependence on hydraulic, mechanical and the bleed air/pneumatic systems and pursue efficiency, reliability and maintainability. At the moment, the lifetime problems of electromechanical actuators, adopted in MEA, have been addressed by analyzing separately the causes of failures, and accelerated tests were proposed for the single components. This project aims at realizing a test bed able to apply multiple age accelerating stresses and to realize the on-line test of the electric machine and drive, under different operating conditions.
The main failure in electric drives is due to electric faults resulting from the damage in the motor winding insulation system. In this work the main stress factors affecting the lifespan of insulation materials in aerospace applications will be analyzed. A special test bed will be also proposed, to assess insulation lifespan modelling under various stress conditions, especially investigating the interaction between ageing factors. The test bed will allow to characterize insulation degradation under variable ambient and power supply parameters for simple models, such as twisted pairs, up to coil form and complete machine operated at rated load. The proposed approach is based on the design of experiments (DOE). The results of the work that will be carried out will allow to identify the most influential factors affecting insulation lifetime and the interactions between them.
The test setup comprises a Thermal vacuum chamber, an embedded dynamometer/brake system and a custom inverter based on SiC devices capable to apply PWM commutation of different dv/dt ratio.
The test rig would allow an all-in-one approach for multi-parameter measurement, thus minimizing the required test runs.
The test set-up will thus provide a means to confirm, experimentally validate, and also fine-tune insulation degradation lifetime models. In particular a lifetime model, based on the physic Of Failure (PoF) method, that considers the impact of the different stress factors on the system, is expected to be developed during the project.
The ultimate goal is to foster the development and adoption of electric drives for aerospace applications, resulting from more reliable procedures that allow accurate estimation of a system lifetime from the design stage (design reliability work flow)
Title: “Impact of wide-bandgap devices on the insulation system of magnetics”
In the last few years wide-bandgap power devices, such as SiC and GaN switches, have been started to market. They provide superior performances respect to their Silicon counterparts, reaching faster commutation and maintaining their efficiency even in case of high temperature operation. Nevertheless, their impact on real system has not been completely investigated. The high dv/dt ratio, enabled by the fast commutation transients of SiC or GaN devices, introduces very high frequency harmonics that can trigger partial discharge phenomena in the windings of magnetics present in the circuit, leading to deterioration of the insulation systems.
For this reasons a trade-off between performance and reliability must be reached to enable the widespread utilization of wide-bandgap devices.
Davide Barater was born in Italy on August 13, 1983. He received Master’s degree in Electronic Engineering in 2009 and the Ph.D. degree in Information Technologies in 2014 from the University of Parma, Italy. He was an honorary scholar at the University of Nottingham, U.K, during 2012. He is now working as a postdoctoral research associate at the Department of Information Engineering, University of Parma, Italy. His research area is focused on power electronics for renewable energy systems, static energy conversion and motor drives. He is a reviewer of IEEE transaction on Power Electronics, on Industry application, on Industrial Informatics. He is author or coauthor of more than 20 international papers, He holds one international patents.