Listening to the radio is a favorite German pastime. Every day, more than 60 million people turn their radios on, especially while driving, and studies show that one in two of them are unwilling to give up enjoying radio programs behind the wheel.
Measuring the electromagnetic compatibility of vehicle components in a laboratory chamber. © Fraunhofer IZM
But in the vehicle of the future, the electric car, listening to the radio is in principle not possible, since electrical interference impedes the reception of radio waves. These disruptions are caused by the frequency converter, which changes electrical energy into mechanical energy so as to control the electric motor’s speed and direction of rotation. These converters turn the current and the voltage on and off rapidly and frequently, and the way they chop electrical energy up in fractions of a second produces electromagnetic interference. If this becomes too loud, you can only hear the electric drive, not the car radio.
To get around this problem, not only must the engine’s cabling be shielded, the motor itself must also be insulated – but this comes with a high price tag for automakers. Fortunately, researchers at the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin have worked out how to significantly reduce these costs. Dr. Eckart Hoene, director of the Power Electronic Systems research group, and his team have developed a whole series of tools and methods for reducing interference. Using new simulations and calculation methods, the engineers can for instance now determine where in the vehicle components should be positioned to keep their electromagnetic interactions to a minimum.
Interference is affected by parts’ position
“The size and position of individual components – including the electric motor, the battery, the air-conditioning compressor, the charging system, the DC/DC converter and the frequency converter itself – play a crucial role. How and in what direction cables are installed is just as important, as is the thickness of their insulation,” explains Hoene. “With the help of simulations, we can also advise on the quality of the insulation and the plug connectors.”
The scientists have measurement techniques that allow them to pinpoint where exactly in the vehicle interference is coming from and to see how it spreads. What’s more, they have developed a symmetrical power module which stops interference from being emitted. This is a component of the converter and already exists as a prototype.
All German automakers have benefited from the Fraunhofer experts’ know-how. But as Hoene points out: “We advise not only German automotive manufacturers and suppliers, but increasingly Japanese and American companies, too.” Tests and fault analyses can be carried out in the institute’s own laboratory.
Electromagnetic interference is not just a problem in electric and hybrid drives. It can be a problem anywhere power electronics are installed: in avionics, or in wind and solar energy facilities, too. “Roofs with photovoltaic arrays will have a solar converter to change the direct current into alternating current, and this can impair radio reception inside of houses,” Hoene adds. Thankfully, he and his colleagues can also provide expertise and advice in these situations to help keep interference to acceptable levels.
Franz Miller | Fraunhofer Research News
Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts
08.12.2016 | Institut für Solarenergieforschung GmbH
Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences