March 2021 COMET News | Comet Consortium

November 3, 2021

News:

Awarded with the ARPA-E project “Novel Light-weight mega-watt Cable System for Large Electrified Aircraft”, which is coordinated by GE. Our work is modelling aging mechanisms, developing stochastic life models, PD measurement and monitoring technology.
Awarded with a new NAVY-ONR contract “Electrical insulation system reliability in the PEPDS project” (included in the broad Power Electronic Power Distribution System (PEPDS) projects).
A chamber endowed with variable pressure, humidity, broad range of temperature and high voltage up to 50 kV has been purchased. We plan to have it installed within 3 months
New testing generator under development, made of a PWM inverter having number of levels and slew rate that can be modified, and voltage up to +- 10 kV. This does not exist anywhere in the market, prototype by April 2021 (in cooperation with Wels University, Austria).
First prototype of a brand-new PD detector delivered to CAPS. It can measure PD with any type of waveform (from DC to power electronics), reject noise, identify PD, evaluate component health...automatically and without the need of experts. COMET students and CAPS researches are being trained. We will test extensively such innovative instrument in CAPS in the next months, in the contest of the activity involved in the consortium and the research projects. It will be of course available to interested participants. Laminated busbars, cables, motor insulation, PCB first candidates.

Reports:

"Insulation Design for Rotating Machines Fed from Converters - Electric field distribution inside stator slots for different conditions and Partial Discharge Inception Voltage"

Contents:

This report investigates the distribution of the electric field inside a stator slot, in the search for localized critical points able to trigger extrinsic accelerated degradation phenomena, when being powered by a repetitive-impulse (e.g. PWM) power supply.
Slots having two wires of trapezoidal shape are chosen for calculations, considering that the wire section can be made by solid copper or winding wires. Low values of voltage are considered, to highlight that electric field can be large enough to trigger partial discharges (PD) already at relatively low supply voltage.
Effect of corona resistant (CR) compared to Non-Corona resistant (NCR) insulation