Microgrid developed to power lunar base
A microgrid to power a future base on the moon is under development at Sandia National Laboratories in the US.
The initiative forms part of NASA’s Artemis lunar base project and the findings are expected to provide inputs to the control and resilience of microgrids here on Earth.
The Artemis programme is aimed to return humans to the moon by 2025 with the establishment of a base at the lunar south pole for several astronauts to live and work for extended periods, potentially up to about two months, and to serve as a stepping-stone and technology proving ground for future travel on to Mars.
The base camp concept comprises a habitation unit and, separated by some distance to avoid interruption, a mining and processing facility for the production of resources such as rocket fuel, water, oxygen and other materials needed for life there and that could decrease the supply needs from Earth.
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NASA is reported to be working on the development of the microgrid controller for the habitation unit, basing it on the International Space Station’s DC electrical system.
For its part, Sandia is focused on the design of the electrical system controller for the mining and processing centre’s microgrid as well as that of a controller to connect the two microgrids, which is envisaged in cases of emergency to maintain resiliency and robustness.
“There are some very important differences between something like an ISS-type microgrid to something that has the extent of a moon base,” says Jack Flicker, a Sandia electrical engineer, who is working on the system that will connect the two microgrids and studying the power flow and operation between them.
“One of those differences is the geographic size, which can be problematic, especially when running at low DC voltages. Another is that when you start to extend these systems, there will be a lot more power electronics as well as a lot more distributed energy resources that will exist throughout the base.”
The goal with the controller for the mining and processing centre, which has been under development for about a year, is to come up with a lunar energy power management system that can efficiently maintain a level system on timescales from less than a thousandth of a second up to seasons.
Testing takes place in the organisation’s specialised Secure Scalable Microgrid facility comprised of three interconnected DC microgrids with custom-built electronics to mimic different power production systems and devices that use electricity.
The system that will connect the mining facility and habitation unit microgrids is expected to include a combination of flexible power routing and over-sizing to ensure there is enough power even if multiple things fail.
The team also is exploring how the connection between the two microgrids could operate, considering issues such as transfer efficiency and stability for different distances, the optimal operating voltage and whether the connection should be DC or AC.
“In a contingency event such as an energy storage system failing during an eclipse, we want to be able to port the power at the mining facility over to the base camp to keep the astronauts safe,” Flicker adds.
Among the testing facilities, the Sandia team also intend to use the Emera DC microgrid on Kirtland Air Force Base to see how a power electronic-heavy system can operate and port power as needed in low energy contingency scenarios.
