On The Radar
One way or another and to varying degrees, aviation is making a transformational switch to replace fossil fuels with electricity. This is driving a need to be able to manage and distribute much higher voltages than the industry has ever needed before, and to do so safely and efficiently.
This has opened a major new opportunity for previously unheralded specialists in equipment such as power contactors and cabling. One such company is TE Connectivity, which is rising to the challenge of helping aircraft manufacturers deal with high voltage direct current loads as high as 1,000 volts. Karl Kitts, the company’s senior engineering manager for advanced systems architecture recently published a paper called Trends in Aerospace Power Distribution that provides a useful summary of the issues now being urgently addressed for new aircraft such as eVTOL air taxis.
Unsurprisingly, safety is a big consideration. “For instance, the amount of time you have to react to a failure condition is much shorter than with traditional power systems,” Kitts told FutureFlight. “So you need much faster circuit protection and the traditional circuit breakers used on aircraft are too slow to react. With these power levels, you could burn through a fuel line very quickly.”
Instinctively, aircraft manufacturers address challenges like this by adding a lot of redundancy, with multiple power control boxes and motors. But, especially for small aircraft like the eVTOLs, space and weight are at a premium and so this can mean compromising performance if the systems are not carefully designed and integrated with the airframe.
TE Connectivity is supporting Textron eAviation by providing power distribution equipment, contactors, over-current relays, and fuzes for the Nexus eVTOL design it is working on. “It’s small so everything has to be lightweight and we’re helping to install it where it’s needed and working with the geometry,” Kitts explained.
Later this year, the company expects to supply the power distribution unit ready for flight testing with a Nexus technology demonstrator. TE Connectivity is also supporting Vertical Aerospace with its eVTOL program.
At the same time, TE’s engineering team is also focusing on how electric aircraft developers can maximize every bit of the power available in today’s batteries. This involves developing solid-state power controllers that automatically assess the state of the charge and control how much is let through to limit surge currents.
Kitts represents TE on the standards body SAE International’s committee focused on power distribution. “There is an overarching foundation for standards around high-voltage power, but there could still be some curve balls with certification [of new aircraft],” he commented. “From a component point of view, I feel confident because the power switches and cabling will be robust, but there could be [development and certification] risk. There is a path forward, though, and it’s fairly well defined.”