As military platforms require more electrical power for mission computing, sensors, communications, and other onboard electronics, higher-voltage DC power distribution can provide an effective way to move significant amounts of power around the aircraft. But not every piece of equipment operates from the aircraft’s higher-voltage bus.
When a platform distributes 270VDC but still requires substantial 28VDC power, designers need a reliable way to create a regulated 28V secondary bus.
The 270V-to-28V Power Conversion Challenge
Converting 270VDC power to 28VDC becomes increasingly challenging as power requirements increase.
At several kilowatts, designers must consider more than input and output voltages. Thermal management, electromagnetic interference, power quality, environmental requirements, protection, monitoring, and the high current on the 28V side all become important system-level considerations.
For example, delivering 7.5 kW at 28V requires approximately 268 amps of output current. Even with high conversion efficiency, hundreds of watts of heat may need to be removed from the power converter.
But performance is only part of the challenge. Defense programs also need power solutions that can meet unit-cost objectives, be manufactured reliably at production quantities, and remain supportable throughout long program lifecycles. Component selection, design complexity, supply-chain availability, and manufacturability therefore need to be considered alongside electrical performance.
The result is a balancing act: delivering the required power quality and performance in demanding environments while also designing a solution that can be produced, supported, and sustained for the life of the program.
A 7.5 kW 270VDC-to-28VDC Solution
Rantec developed the PL40328 Defense Power Converter to address this class of high-power conversion requirement.
The liquid-cooled converter accepts a nominal 270VDC input and provides up to 7.5 kW of regulated 28VDC power. Its 240–350VDC steady-state input range accommodates variations in the platform’s power bus, while the unit is designed for input transients up to 420V.
The PL40328 provides:
– Up to 7.5 kW / 268A of regulated 28VDC power
– 240–350VDC steady-state input range
– Up to 92.5% efficiency at full load
– Maximum weight of 11 pounds
– 28V power quality per MIL-STD-704F
– EMI performance per MIL-STD-461G, including RE102 and RS103
– MIL-STD-810H environmental performance
– Startup and continuous built-in test
– MIL-STD-1553B communications
– Integrated monitoring and protection features
The result is a compact, rugged source of 28VDC power for demanding military and aerospace applications.
One Architecture, Different Power Requirements
Not every platform needs exactly 7.5 kW of 28V power.
The PL40328 was developed around a modular internal power architecture, giving Rantec a technical starting point for applications requiring different levels of 28V output power.
That is particularly important in defense power conversion, where electrical, mechanical, thermal, communications, and environmental requirements frequently vary from one platform to another.
Rather than beginning every new 270V-to-28V requirement from a blank sheet, an existing power-conversion architecture can provide a starting point for evaluating a customer’s specific application.
Evaluating a 270V-to-28V Requirement?
If your platform generates or distributes 270VDC but requires a regulated, multi-kilowatt 28VDC bus, Rantec can help evaluate the power requirement and determine whether an existing or modified solution is appropriate.
Explore the PL40328 270VDC-to-28VDC Defense Power Converter or contact Rantec to discuss your application.
