Modular power addresses increased demands in aerospace and defense applications

Article By : EEWeb

Increasing DC/DC converters' power density in the MIL-COTS market has tremendous benefits, including a reduced budget for size and weight that allows military power systems designers to focus more on the C4ISR capabilities required in their demanding applications.

The aerospace and defense market continues to ramp up the demands, with the need for further size and weight reduction along with excellent system capacity to maintain high power efficiency. The solutions required for these applications must meet the increased power density, capacity, and time-to-market requirements, and traditional DC/DC converter bricks are struggling to do so. To overcome this challenge, it is necessary to choose the right power delivery network and employ high-density power modules.

Increasing DC/DC converters’ power density in the MIL-COTS market has tremendous benefits, including a reduced budget for size and weight that allows military power systems designers to focus more on the C4ISR capabilities required in their demanding applications. Vicor Corporation offers such solutions to meet size, weight, power, and cost (SWaP-C) requirements with a portfolio of low-noise, high-power-density modules.

“A good example is our DCM family of isolated and regulated DC/DC converters,” said Rob Russell, vice president of product marketing at Vicor. “When compared with the best brick package solutions, our innovative ChiP and VIA packages enable solutions with 2.5× the power density by volume and more than 3× the power density by weight.”

Modular power design for defense applications

Vicor’s configured DCM capability minimizes the non-recurring design costs associated with specific converters. High-frequency switching of DCMs simplifies the filtering required to avoid increased interference.

The DCM5614 (270 V to 28 V, 1,300 W, 96% efficient) operates from a 180- to 400-VDC primary source to deliver an isolated, regulated, 28-V nominal, safety extra-low-voltage (SELV) secondary output. This module, available in chassis- or PCB-mount form factors, incorporates a DC/DC converter, inrush protection, and optional analog or digital communication. The PMBus-compatible offers telemetry and control interface to configure fault monitoring and other telemetry functions.

For aircraft loads, the DCM5614 (141.43 × 35.5 × 9.4 mm) converts the 270-V bus available throughout the aircraft down to 28 V where needed and delivers 1,300 W to the load.

To provide EMI filtering and transient protection, Vicor offers the MFM filter family to enable the designers to meet conducted emission/conducted susceptibility per MIL-STD-461E/F and input transients per MIL-STD-704 or MIL-STD-1275 for the 28- or 270-V nominal input voltage DCM modules in a VIA or ChiP package.

“The rest of the DCM family is also very well-established and used in many military applications such as UAVs, radar, and various robotic applications,” said Russell.

The DCM family’s high efficiency of 96% reduces the size of a required heat sink, saving even more space. In the below figure, the DCMs are paralleled to increase the required power, and converters can be added for future power requirements. The ability to parallel DCM modules greatly reduces time to market when applications need to scale based on changing load requirements.

An array of three 1.3-kW DCM5614 VIA converters. They provide the regulated 28-V bus. (Source: Vicor – Aerospace)

The growth of AI creates opportunities and power challenges

More defense applications are capitalizing on artificial intelligence to ensure safer and more effective operations. As a result, power delivery is being further taxed by the adoption of AI in military applications. “This is mirrored in commercial applications where power consumed by ASICs and GPUs processes complex AI workloads,” said Russell. “In most cases, power delivery is now the limiting factor in computing performance as new processors draw ever-increasing currents.”

Power delivery entails not just the distribution of power but also the efficiency, size, cost, and thermal performance of the power-conversion solution. “Working in partnership with the industry’s top processor companies, Vicor has established a portfolio of products enabling AC or HV distribution and Factorized Power Architecture solutions for 48-V direct-to-load conversion,” said Russell.

He pointed out that the 48-V distribution provides a maximum SELV voltage that reduces distribution losses by 16× over conventional 12-V distribution. All of these products feature the high density and high efficiency required to meet the needs of large-scale computing systems utilizing the most advanced CPUs, GPUs, or ASICs. Soon, the commercial processor technology will be required in aerospace and defense AI applications, and therefore, the innovative, high-performance solutions that Vicor has developed for AI will be needed there as well.

Packaging delivers power density for military innovations

Packaging plays a critical role in the ability to deliver high-density power. “Without innovation in power module packaging technology, advances in power density, current density, and efficiency could never be achieved,” said Robert Gendron, vice president of product marketing at Vicor.

Vicor’s latest innovation in packing technology is called “ChiP” (Converter housed in Package). It is made and cut from a standard-sized PCB panel, with both sides being used for active and passive components. Thermal management is a prime consideration in module construction, taking into account a cooling design on both sides to maximize performance and power density.

“DCM modules employ innovative power conversion and regulation switching controllers to enable further advances in efficiency, power, and current density,” said Gendron. “These attributes, coupled with the addition of advanced packaging to manage the space, thermal, and environmental challenges, make the DCM product line an ideal choice for aerospace and defense system designers.

“As the defense and aerospace market continues to innovate and grow, compliance and reliability standards will be maintained to ensure safety and performance,” he added.

Power solutions will still need to meet challenging SWaP-C requirements, and more power will be demanded within the same footprint or smaller. To achieve these evolving requirements, a module approach to power design is beneficial to deliver reliability, flexibility, and power density.

This article was originally published on EEWeb.

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