Tim Guest
Modern warfare relies on electrical power like never before to drive, run, or operate a plethora of equipment across airborne, naval and land domains. This article looks at how the need, by military systems – many of which are becoming increasingly smaller every day – for readily-available power and its ‘measured’ delivery to various sensors, weapon systems and ancillary equipment, relies on power electronics of various kinds and why this market is only set to grow massively.
Military systems, both small and large, require electrical power to be delivered to them, often in very specific ways and amounts, if they are to perform optimally. Power electronics, such as voltage regulator systems, transformers, conversion systems, help ensure power, from source to application, meets the right parameters for the job at hand.
Overview
Power electronic systems are found in almost all electronic equipment delivering power conversion of AC to DC, DC to AC, AC to AC, DC to DC, power conditioning to remove distortion or harmonics, voltage dips and over-voltages. And they are also used for high-speed and/or frequent control of electrical parameters such as currents, voltage impedance, and phase angle. In most mobile devices, ruggedized tablets, for example, increasingly adopted by military users, DC-DC converters are used to maintain voltages at a steady, fixed level, no matter what the device’s battery voltage level is; such converters are also used for electronic isolation and power factor correction. Another type of DC-DC converter is the power optimiser, developed to maximise the power supplies that can be harvested from renewable energy sources, such as solar photovoltaic cells and wind energy, both widely used as power sources in military smart energy and water applications. Another power electronic solution is the rectifier, or AC-DC converter, a solution employed every time an electronic device, such as a computer, a field medical monitor, or a video monitor screen, is connected to a mains or generator-based electricity supply. Rectifiers might only convert AC to DC, though they can also change voltage levels to the equipment. In addition, voltage regulator systems, mains power transformers and frequency converters are just some of the other power electronics widely used in a range of tri-service and space-based scenarios, from naval on-board electronics and propulsion, to aircraft starting, support and maintenance equipment, tank and armoured vehicle simulation and training suites, satellite design, drone systems and more.
In modern electronics, such power conversions as mentioned are performed with ever smaller semiconductor switching devices, including diodes, thyristors and power transistors, including the power ‘metal oxide semi-conductor field effect transistor’, or MOSFET, and the Insulated-Gate Bi-polar Transistor, or IGBT. Gallium arsenide (GaAs) and laterally diffused MOS (LDMOS) have been used in electronic systems and devices for many years and silicon-based LDMOS FETs as well as GaAsFETs are now widely used in RF and millimetre wave communications solutions. But the need for small ‘size, weight and power’ consumption (SWaP) devices in military systems is, today, one of the key reasons that advances in semiconductor technology and component integration is so important in helping equipment manufacturers achieve the smaller end-product sizes users demand.
Trends
With defence systems typically requiring very reliable electrical power in the form of three-phase/single-phase AC, or 50 Hz/400 Hz, or regulated 5, 12, 24, 28, or 48-Volt DC, no matter what shape the electrical power takes the conditioning and control of electrical power supplied to increasingly smaller and highly sensitive electronics components inside latest military systems and equipment, is being guided by certain trends. Such trends include the need for more acute cooling and thermal management, open architecture adherence, striving for greater power-density and SWaP, as well as a much greater use of commercially off-the-shelf systems. The quest for miniaturisation in many defence systems is one of the reasons driving the trend in SWaP; as user systems demand evermore power density from the smallest possible batteries, components, or power storage devices, this size and weight reduction in, for instance, the electrification of vehicles and aircraft, and in satellite design, is critical. And with a growing number of vehicular defence applications involving electrical powertrains and greater electrification of all onboard systems, including advanced, specialised sensors, many requiring their own dedicated and reliable sources of high-quality electric power, exacting use of power electronics is critical. Such systems as azimuth and elevation servo drive units, outrigger drives, various power and servo amplifiers, communication systems, radar, consoles and displays all require their own main and stand-by power sources, in turn needing effective power electronic solutions helping to manage the electrical conversion and delivery, from source to application, across the platform.
Market
If there’s any doubt about the importance and widespread nature of power electronics solutions and use, a recent report on the market in both the defence and commercial arenas, by Fortune Business Insights, is worth a brief mention. It looks at the very latest trends and developments in this critical area of electronics, addressing and separating out its analysis of power electronics solutions by type, material, voltage, end-user and ending with a regional forecast and market projections from 2021 out to 2028. The report underscores the importance of power electronics in the support of power management solutions that will both improve energy conservation while reducing energy losses from systems such as aircraft engines, satellites, military vehicles and weapon systems. It explains that a rising demand for automated weapons and electric vehicles for military applications alongside the growing aerospace and defence industries in the economies of China and India will drive growth opportunities for the power electronics sector in the coming years.
The report says that progress in technologies enabling the development of evermore advanced semiconductors, nanotechnology and the Internet of Things are expected to propel the power electronics sector in the forecast period. That said, silicon is, according to the report, likely to remain the most widely employed material used in power electronics for some time due largely to its availability, compatibility with a variety of substrate materials used in power electronic production, as well as low production costs themselves. It also describes a rising need for high power density IGBT modules, (as mentioned earlier), in aircraft applications due to lightweight and advanced feature design criteria demands, including moves to arrive at all-electric systems. Indeed, IGBT module demand is set to increase rapidly in order to improve electronic device performance and reduce the overall weight of aircraft and advanced weapon systems, as well as spacecraft of all descriptions.
As for some of the key players in the power electronics space, the report makes mention of companies across the globe, including: TT Electronics in the UK, STMicroelectronics in Switzerland, Infineon Technologies in Germany, NXP Semiconductors in the Netherlands, Renesas Electronics and Mitsubishi Electric Corporations in Japan, as well as a range of US players such as Microsemi, Texas Instruments, On Semiconductor, Collins Aerospace and others.
Regional splits for global analysis in the report are: Europe, North America, Asia-Pacific and the rest of the world, with North America set to lead the way in the coming years driven mostly by its quest for advanced weapon systems and its space programme. Taking second place, however, is the AP Region with China’s military industrial complex and its race to achieve global military superiority with advanced weapons cited as driving main demand, bolstered also by its space programme and the space programmes of regional neighbours, India and Japan.
Outlook
As the above report illustrates, power-hungry military systems and sensors that require reliable and high-quality power, managed and precisely delivered for everything from handheld drones, communications, satellites, vehicle-borne and soldier-worn sensors, naval propulsion, hybrid-electric drives, aircraft engines and more, will ensure the health of the power electronics sector for years to come and drive its R&D to find new ways of doing the same things, though in smaller, lighter, more efficient packages.