Fixed-winged HALE UAV

Upgrades to a high-altitude long-endurance (HALE) UAV platform challenges design engineers when retrofitting a new, higher-resolution, longer-range radar and improve telemetry. The upgrade effectively doubles the power required on the 28V internal bus to 11kW. On-board power is from two separate power sources for redundancy. The key goals are to double the power without allocating more space for the power supply, keep the aircraft as light as possible for longer flight times, improve reliability and ensure adaptability to power needs in the future.

The power delivery network

The small size, low profile and low weight of the Vicor DCM™ DC-DC converter module enabled the design team to meet their goal and double the output power without exceeding allocated space constraints. The high efficiency (96%) reduced the size of the heat sink required, saving more space. Key outcomes were an 11kW solution in the size of a tablet computer weighing only 215g, DCMs easy to parallel for future increased power needs, low waste heat and reduced cooling requirements. Three arrays of three 1.3kW DCM5614 VIA converters were paralleled to provide the regulated 28V bus. Inputs were split between two different generators to provide redundancy of power source. The arrays automatically power shared across all nine converters —though their input voltages differed — helping improve system reliability.