The project comprehends 4 work packages, reflecting different project stages. Each work package consists of two or more tasks and it is supervised by a Work Package Leader in charge of controlling the correctness of the work and respect of the timeline.
• WP1 - Assessment Of Voltage Gradients /Magnitudes Observed Within Insulation Systems
• WP2 - Assessment Of Partial Discharge And Breakdown Behaviour Of Components Exposed To High Voltage Gradients:
• WP3 - Lifetime Characterisation Of Components Exposed To High Voltage Gradients:
• WP4 - Management and Dissemination:
For WP1, UniMore proposed a model to assess the voltage gradients and the magnitudes observed for typical converter – cabling – machine systems, along with the voltage distribution within typical electrical machine windings, and its dependency on machine’s key parameters, such as the number of turns, the winding method used and the stator length. UniMore also conducted a survey on the best solutions to reduce voltage gradient without compromising converter performance.
For WP2, the impact of increasing slew rates on the partial discharge and breakdown behaviour of typical components used in the aerospace environment has been investigated, including the impact of varying pressure, humidity and temperature, voltage level, rise time. The behaviour of the partial discharge inception voltage (PDIV) as a function of voltage gradient, frequency and ambient pressure has been investigated. A test set-up was built for the investigation. The test set-up accounts for a custom SiC pulse generator designed by UniMore and a variety of Partial Discharge detectors, as photon-counters, photomultipliers and antennas.
For WP3 the activities quantified the impact that higher voltage gradients have on the lifetime of electrical machines and the connecting cables / connectors. Possible solutions identified in WP 1 and 2 were investigated.
This analysis led to an update of the verification / qualification methods considered in WP 2. The WP has provided recommendations for the design of insulation systems when using high voltage gradient systems and defined Type/Qualification test guidelines for the verification of complete stators. Potential limits and challenges of the current methods used in aerospace have been identified and solution proposed.
The consortium disseminated non-confidential results to the Research, Industrial and Public communities:
A web-site was realized within the first year of the project
https://www.raise.unimore.it/(odnośnik otworzy się w nowym oknie).
A special session at international conference IEEE IECON 2019 was organized
The results of the research have been submitted to international conferences (6) and journal (3).
