Electronics Engineering for Cleaner Skies

Learn more about the products mentioned in this story here:

• 5 Series B Mixed Signal Oscilloscope
• IsoVu Isolated Probes
• Spectrum View Feature

The Reliable Aircraft electrical Insulation System sElection project – better known as RAISE – is a 30-month long endeavour to support innovation in electrical insulation for electrical machine windings. It’s supported by Clean Sky, the largest European research programme focussed on reducing CO2 emissions and noise levels from aircraft.

Professor Giovanni Franceschini member of MElting Lab from the University of Modena and Reggio Emilia (UniMoRe) is part of the engineering consortium leading the project. We spoke to him about engineering, the challenges of RAISE and how Tektronix products are helping them achieve their goals.

Professor Giovanni Franceschini – University of Modena and Reggio Emilia using the 5 Series B MSO.

"In recent years, making aircraft design more electric has been one of the most challenging innovations in aerospace," says Giovanni. "Given harsh conditions, and with the need for increasing power densities, there are concerns about insulation system integrity."

One of the key tests is whether state-of-the-art insulation materials can cope well with higher supply voltages and higher switching gradients. As new aircraft design adopts wideband gap devices, the research group focusses its investigation on the impact of increasing slew rates on the partial discharge and breakdown behaviour of typical components. But early on, they found they needed help from us.

"We couldn't find equipment capable of making measurements such as the high-side gate-source voltage. In fact, most differential signals in the presence of today’s higher frequency common mode voltages cannot be measured accurately. That’s when Tektronix stepped in," explains Giovanni.

The testing need was essentially to assess, if state-of-the-art insulation materials of machines and power electronic components are suitable for future applications using higher supply voltages and higher switching gradients coming from the adoption of wideband gap devices.

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Professor Giovanni Franceschini from UniMoRe and his colleagues Professor Davide Barater & Dr Stefano Nuzzo.

The testing scenario addresses representative aerospace environmental conditions and dependency on AC supply voltage (3 phase 115Vrms vs. 3 phase 230Vrms) with a maximum DC link voltage of 1000V. Slew rates of up to 20kV/μs, will be considered as well as increased voltage levels that may be faced in future aircraft designs. Among several other outcomes, the focus is on the impact of increasing slew rates on the partial discharge and breakdown behaviour of typical components used in the aerospace environment.

We recommended they match Tektronix IsoVu probes with the 5 Series B MSO. (1 GHz bandwidth, 4 analog channels). "We used the Spectrum View feature for frequency domain evaluation with high accuracy across the entire spectrum, while monitoring the behavior of a specific transition. So we could better understand the impact of fast transitions on the insulation degradation mechanism."

IsoVu isolated probing systems make high-resolution measurements in the presence of common mode signals or noise.

Giovanni says no other test and measurement supplier could give them what they needed to do the job right. “If you’re using a traditional differential probe, you might not realise the trade-offs and limitations when measuring in an environment with common mode voltage or interference. Only the Tektronix equipment we used could give us visibility of fast gradient signal impact on insulation."

For Giovanni, working collaboratively is always a bonus. He works alongside UniMoRe colleagues Professor Davide Barater and Dr Stefano Nuzzo, as well as participants from the University of Bologna, and says this is “very fulfilling".

RAISE also represents the continuation of a life-long love of engineering. “Even as a child, I loved to disassemble everything! Then at 17, music was a huge part of my life, so I looked into audio reproduction, recording and all that. I knew then I wanted to be an electronics engineer."

We asked Giovanni what keeps him motivated and connected to that youthful love of taking things apart to see how they work. "As a professor of a university now, I love working with young people and enabling their successes. They're so enthusiastic! I've kept that curiosity about the electrical world. Things change so quickly these days and working with young people keeps me young too."

At Tektronix we support the problem solvers, like Professor Giovanni Franceschini from UniMoRe. The relentlessly curious engineers. The people who push the boundaries in science and technology to start making tomorrow better, today.

We’re Tektronix, and we're for the engineer.