Powering the Next Generation of Aerospace Testing
Evolving aircraft power systems, from AC networks to HVDC architectures, are driving new requirements for flexible, high-performance test solutions
Figure 1: MEA architectures have resulted in the growing adoption of high-voltage power distribution and the need for enhanced test equipment such as programmable power supplies
The drive to create lighter, quieter, and more efficient aerospace platforms has driven an industry-wide trend toward more electric aircraft (MEA). In the commercial sector, for example, there has been a rapid increase in onboard electrical systems, which support a broad range of functions. These include power generation, conversion and distribution, flight and mission systems, propulsion and aircraft operations support, cabin services and passenger infotainment.
The shift to MEA architectures has resulted in the growing adoption of high-voltage AC and DC power distribution (±400 Vdc, 230 Vac). It has also driven the need for higher power density, improved efficiency, and faster response times in order to maintain and enhance overall operational performance.
Onboard power architectures for modern aircraft
So, let’s look at how onboard power requirements for these types of systems can be met by a flexible combination of both AC and DC networks, and how such architectures can be replicated by modern programmable power supplies.
Firstly, on the AC bus, traditional power systems have relied on 115 Vac (line–neutral) / 400 Hz. This is a well-proven architecture that is widely used on major in-service passenger aircraft, including the Airbus A320 and A350, and the Boeing 737 and 777.
Meanwhile, 230 Vac (line–neutral) / variable frequency (360 – 800 Hz) represents a more modern AC system used on newer aircraft. Unlike the fixed 400 Hz standard, which requires constant-speed drives to maintain a constant frequency, this variable-frequency approach allows the electrical system to be directly coupled to engine-driven generators without such equipment. As a result, the generator speed – and therefore the output frequency – varies with engine operating conditions. Using higher voltage reduces current for a given power level, allowing lighter cabling and contributing to overall weight savings. This approach has been successfully deployed on aircraft such as the Boeing 787 and Airbus A380.
In DC networks, 28 Vdc is the standard DC system on aircraft, primarily powering the cockpit and essential systems. Again, it offers a simple, extremely reliable architecture, well proven over many years. Additionally, ±270 Vdc provides a higher-voltage DC system increasingly used in MEA. Here, higher voltage means lower current, allowing thinner, lighter wiring. The symmetrical ±270 V layout also improves safety and reduces electrical noise. This onboard electrical power network is used on commercial aircraft such as the Boeing 787, Airbus A350, and A380.
Furthermore, ±400 Vdc and 800 Vdc networks are also deployed, providing very high-voltage DC systems for future and experimental aircraft. Very high voltage enables very high power with minimal wiring weight and is seen as a key enabler of advanced concepts such as MEA and hybrid-electric systems. It is used in research programmes, hybrid aircraft, and high-power transport aircraft.
The need for programmable power suppliers
As onboard aircraft architectures develop; engineers have become ever more reliant on programmable power supplies to help replicate increasingly complex aircraft electrical networks. These instruments generate highly controllable waveforms, allowing users to select parameters such as voltage, frequency, phase, and waveform shape. These outputs confirm the performance, reliability, and safety of a broad range of electrical and electronic devices featured on aircraft by simulating various power conditions they might encounter in the real world. By rigorously assessing products under strictly controlled laboratory conditions, engineers can confirm they adhere to relevant industry standards and will, therefore, operate reliably and repeatably in diverse and demanding operational environments.
However, test engineers in aerospace environments face specific challenges related to power supply requirements. They need to simulate rapid load variations and transient events to ensure high stability and precision for mission-critical electronics. They must achieve very low noise and EMI levels and scale power systems to match different test environments. They also need to support voltage ranges from 28 Vdc through to modern 800 Vdc networks, covering the diversity of onboard electrical architectures found in today’s aircraft. Engineers expect programmable power sources to deliver very low total harmonic distortion (THD) and high peak current capability to support demanding, transient-rich avionics applications.
Ergonomic factors should be considered as well. Increasingly, engineers expect the same level of user-friendly design on their test benches as they experience from consumer devices such as smartphones. This means easy-to-use software and graphical displays, along with scalability and modular solutions for different test setups. And lifecycle support is important. Aircraft platforms can be in service for up to 30 years, and primes expect to keep at least one test bench operational for ongoing maintenance in the long term.
Meeting the requirements of test engineers
So, how are these expectations translated into next-generation AC and DC programmable power supplies? It starts with test equipment that can simulate both legacy and emerging aircraft power networks. That includes AC (115 Vac / 400 Hz) and DC (28 Vdc), as well as more recent power networks developed through MEA initiatives, including 230 Vac / 360 – 800 Hz, ±270 Vdc, ±400 Vdc, and 800 Vdc high-voltage networks for next-generation aircraft, along with 800 V battery systems.
Meeting these requirements demands AC sources that can operate reliably well beyond 400 Hz, and DC supplies capable of supporting both bipolar and high-voltage operation.
Other technical requirements are met through a modular architecture. This enables scalable power expansion and parallel operation in both single- and multi-phase configurations. It should also deliver very low ripple and total harmonic distortion, low noise and EMI, and a fast transient response for realistic load simulation, along with high peak current capability.
In practice, operational performance must also be delivered through high robustness, supported by warranties, easy-to-use software, and a very compact design. While AC capability remains critical for traditional and variable-frequency aircraft power systems, support for high-voltage and bipolar DC networks is now equally essential as MEA and hybrid-electric architectures mature.
The Latest Thinking for Test Equipment
TDK Lambda’s GENESYS AC PRO illustrates the latest thinking in programmable power supply design for aerospace testing. It combines wide frequency operation up to 5 kHz, high-voltage AC and bipolar DC capability, and fast transient response to accurately replicate both legacy and emerging aircraft power architectures.
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Figure 2: GENESYS AC module
The platform also delivers low THD and high crest factor performance, enabling realistic simulation of non-linear and pulsed avionics loads without compromising test integrity. Its single-range DC output, support for ±270 Vdc to ±400 Vdc networks, and scalable power architecture provide the flexibility required for MEA and next-generation platforms, while built-in test profiles, intuitive control interfaces, and compact form factors help reduce setup time and improve repeatability, streamlining day-to-day laboratory operation.
But what comes next? How will suppliers ensure they continue to meet the needs of test engineers as more electric aircraft increasingly come to the fore?
Continued product evolution could mean automatic over-the-air updates, the addition of new test routines and profiles, and the capability to remotely adapt software / firmware to meet changing standards and test environments without operational disruptions. There is increasing demand for a bidirectional DC power supply that supports the integration of a high-voltage battery at 800 V across more aircraft platforms, and this is likely to result in new product introductions in the near to medium term.
Ultimately, test and development engineers want a continually refined programmable power offering that reflects the increasing need for precise and flexible power control across industries. Many end users also seek commonality with AC and DC programmable power devices, enabling them to streamline operations and work more efficiently.
Supporting the More Sustainable Aviation of Tomorrow
In conclusion, adopting more electrified architectures will lead to the development of lighter, more efficient aircraft with enhanced operational capabilities. Test engineers will continue to use their skills to ensure the performance of myriad onboard electronic systems and components covering the entire airframe.
Programmable power has emerged as a critical building block of these test activities. The latest generation of equipment provides functionality, reliability, and usability, along with ease of operation and signal purity, to ensure engineers can perform tests efficiently and repeatably, making better use of their time and resources. High-quality, technically advanced programmable power supplies can genuinely enhance testing operations by identifying more potential problems, resulting in optimal performance of critical equipment in the harshest operational environments.
