DMI DS30 hydrogen fuel cell drone, 2-hour flight
Long-duration drones require power pack PDN optimization
Bycor Supports PDN Design with Modular Regulators The utility of drones is increasing with the introduction of hydrogen fuel cells.
In 2020, Doosan Mobility Innovation (DMI) conducted a demonstration of the hydrogen fuel cell drone 'DS30' capable of flying for 2 hours in the U.S. Virgin Islands and Jeju Island. DMI's hydrogen fuel cell technology laid the foundation for accelerating the development of mobile robots through extended flight distance and load capacity.
▲ Emergency medical supplies delivery in the U.S. Virgin Islands
DMI DS30 hydrogen fuel cell drone being demonstrated [Photo = DMI]
In addition, the possibility of commercial applications was confirmed by completing extensive solar panel testing at Haenam Solar City, the largest solar power plant in Korea. To perform the same mission under the same conditions with a drone equipped with existing batteries, more than six battery replacements would be required.
▲ DS30 used for solar panel inspection [Photo = DMI]
Developing hydrogen fuel cells for mobility requires comprehensive technological innovations, from material science to system-level design optimization. The core of mobility is miniaturization, weight reduction, and efficiency. In addition, high energy output and durability are required to ensure stable long-term flight.
To achieve this, the system must be optimized by reducing the weight of the stack itself, configuring a powertrain with high power density, and simplifying the design of the entire power pack, including peripheral components. At the heart of this design is the system's Power Delivery Network (PDN) implementation and architecture.
▲ Hydrogen fuel cell and lithium polymer battery
Energy Density Comparison [Graph=DMI]
The 'DP30' power pack mounted on the DS30 drone consists of two main powertrain structures that supply power to the drone's rotor, stack controller board, and fan. Based on a wide range of variable output voltages from 40V to 74V, the DP30 power pack guarantees a regulated 48V, 12A output to the drone's rotor side, and consistently supplies 12V, 8A output to the stack controller board and fan.
DMI selected Vicor’s Pre-Regulation Module (PRM) buck-boost regulator and Zero-Voltage Switching (ZVS) buck regulator to achieve high efficiency and high power density in the PDN. PRM can support the OCV (Open Circuit Voltage) of hydrogen fuel cell stacks up to 74V and performs stable voltage regulation up to 48V.
▲ Hydrogen fuel cell power pack structure [Photo = DMI]
The drone's rotor-side PDN uses two Bycor's 'PRM Buck-Boost Regulators (PRM48AF480T400A00)' in parallel to supply the 12A required by the rotor. The stack controller board-side PDN uses 'PRM Buck-Boost Regulators (PRM48AH480T200A00)' and 'PI3546 ZVS Buck Regulators (PI3546-00-LGIZ)'.
In addition to the 2.6kW DP30 power pack currently in production, DMI is diversifying its product line by power capacity. We plan to develop products of various capacities, including a 1.5kW hydrogen fuel cell power pack scheduled for release this year, up to 10kW, and also release drones with new structures suitable for each power pack.
▲ Bycor regulator adopted in DMI DS30 drone [Image = Bycor]
DMI will leverage Vicor’s modular approach to power to provide scalability across multiple product lines, while addressing engineering challenges such as stack architecture changes as power capacity increases, powertrain and peripheral components, and heat dissipation.
기사입력2021.01.12 15:45
