Ready for take-off with electrical safety

The electric drive is revolutionising aviation – Bender ensures electrical safety

Quieter, more efficient and more climate-friendly: this is what air traffic could look like in the future thanks to electric drives. That said, a great deal of basic research is still needed for this vision to become a reality. With its expertise in the field of insulation monitoring of IT systems, which is unparalleled worldwide, Bender is an industrial partner in the EU project IMITAES, which researches electrical safety in electric aircraft. For Bender engineers, the project represents an exciting challenge that they are happy to tackle.

The Clean Sky programme

IMITAES (Insulation Monitoring for IT Aircraft Electrical Systems) is a sub-project of the EU’s Clean Sky programme, which develops innovative technologies to reduce aviation-related emissions within the framework of public-private partnerships. The main objective of IMITAES is to conduct a feasibility study and set up a laboratory for Technology Readiness Level 4 for an insulation monitoring device that works in electric aircraft to enable safe electric flight. The project is coordinated by the University of Sheffield. The aircraft engine manufacturer Rolls Royce compiles the catalogue of requirements in its role as Topic Manager, while Bender develops the necessary technology.

Complex electrical safety

An all-electric or hybrid-powered aircraft places completely different demands on the electrical on-board network than aircraft with gas turbine propulsion because the electric engines require significantly higher voltages and much greater amounts of power. “We’re talking about high-voltage networks of up to 1,500 V/DC and powers in the megawatt range. And as the size of the electrical system increases, the issue of electrical safety also becomes more and more complex,” explains Tobias Groh, Head of Research in the Standards & Innovations department at Bender. In concrete terms, this means that a large number of intelligently planned redundancies need to be created and monitored to maximise the safety and availability of the power supply. Ensuring that such a complex system functions in the megawatt range is a challenge when it comes to measurement technology. “But it’s a challenge we can master at Bender,” confirms Groh, confident in the strength of his team of developers.

A fail-safety expert

One of the reasons behind the selection of Bender as a partner for the IMITAES project was the fact that the company offers many years of experience and superior knowledge in three areas that are crucial for electrical safety in electric aircraft: IT systems, insulation monitoring and complex applications. “Fail-safety is the central issue when it comes to the electric power supply in aircraft, namely making sure that power really is always there,” explains Tobias Groh. “At Bender, we are well aware of this issue from our work with many of our customers in sensitive areas such as hospitals, power plants or data centres. These customers very often use IT systems, which are unearthed systems.” The advantage of IT systems is that if an insulation fault occurs, it is reported, but the system does not have to be switched off. As a result, an electric aircraft can continue to fly safely until landing, even in the event of a fault.

Monitoring is part of the Bender DNA

The monitoring of the IT system plays a key role in meeting the requirements outlined above and has been Bender’s core competence throughout its company history – starting with the invention of the ISOMETER®, the first patented insulation monitoring device. An insulation monitoring device especially for electric aircraft not only needs to be designed to deal with high voltages and electrical power but also has to cope with the high dynamics in the energy demand of the electric aircraft drives and the extreme environmental conditions faced at high altitude. Bender is already familiar with such complexity from other applications, explains Groh: “We have experience with electrical systems on trains and in the world of Formula 1, both of which also involve high amounts of power in motion. As a result, we are aware of the specific problems posed by such networks and can quickly develop good solutions for tackling them.” In addition, Bender has already gained initial experience with electric flight: components manufactured at its site in Grünberg are installed in the “Spirit of Innovation”, a small all-electric demonstration aircraft made by Rolls Royce.

Making innovations safe

Bender has developed a completely new technical solution for the insulation monitoring device that is being created as part of the IMITAES project. The development process was aided by the comprehensive expertise and experience of the team in Grünberg and was also supported by the company’s outstandingly equipped test laboratory. The developers were therefore able to not only simulate the effects of environmental factors such as humidity, temperature fluctuations and vibration on electrical safety and the components used in the aircraft on the computer but also test them in their own test laboratory.

A competent problem solver

With the basic research that Bender has been conducting for many years, the company has established a special reputation in the industry. “Many customers come to us when they have a problem that nobody else can solve,” declares Tobias Groh proudly. Needless to say, prestigious international projects such as Clean Sky and IMITAES also involve a high degree of pressure to perform. “But being at the forefront in such a prominent position and fundamentally developing sustainable mobility is also an excellent challenge,” states Groh. The IMITAES project will conclude in June 2023, but Bender is also ready and waiting for the next step: helping to prepare the necessary standards for electrical safety in electric air traffic in the relevant committees.