Due to reduction of losses and optimisation in aircraft designs, aircrafts are more electrical. This perspective takes place in an environmental respect context. One main goal of CleanSky project was to improve Systems for Green Operations (SOG). Management of Aircraft Energy (MAE) was one of the most important challenges. HDSPC project took place in this context.
In these kind of specific products, EUROFARAD heritage in plastic film capacitors was fundamental. Moreover, a good comprehension in customer requirements (mechanical, electrical, thermal …etc.) was essential for the actual demand but also to understand problematic for future design. Management of aircraft energy led EUROFARAD to focus on the same goals as our customers:
- Higher working temperatures;
- Higher energy density (also means weight reduction);
- Possibility for sensing capacitors for self-diagnostics (lifetime and control).
During HDSPC project, our main goals were to improve our technology in term of working temperature and miniaturisation. Special attention was paid on material analyses and choices: both plastics polymers for capacitors but also capacitor covering materials in aeronautics environment. Moreover, R&T was done on the SMART capacitor, with the main goal of providing physically integrated (into the capacitor) solution for sensing “state of the capacitor” under electrical control signals.
Performances and reliability improvement of passive power devices has become a major issue in the actual context of electrification of the transportation and energy industries. The High Dense Smart Power Capacitor (HDSPC) project was launched in order to evaluate the potential of a new capacitor technology for the next generation of aircraft power converters. Technology demonstrators had been designed and manufactured and a new plastic film dielectric had been qualified for high miniaturisation at 155-165°C. The technology also showed good results for 155°C applications.
Metallised film capacitors are highly reliable components due to low failure rates and to a secure open-circuit failure mode. However, health monitoring approaches can lead to optimised maintenance costs and to a significantly increased reliability. The HDSPC project achieved the development of a diagnostic algorithm allowing the on-line monitoring of the DC-Link capacitor’s aging signature parameters. This was achieved through signal processing of current, voltage and temperature measurements at the capacitor’s leads. Moreover, an aging law for the capacitor’s capacitance value had been developed based on the physical phenomena occurring operation. The combination of these developments constituted an efficient tool to provide in real time the capacitor’s effective remaining useful lifetime. This approach had been validated through simulations and experiments but its implementation into an actual converter still has to be performed.