German researchers develop quick and easy way to measure power consumption

May 16, 2012 // By Paul Buckley
Researchers at the Fraunhofer Institute for Integrated Circuits IIS in Erlangen have developed a novel, space-saving metering unit that can be simply clipped onto a power cable like a laundry peg, without even having to disconnect the load.

The new ‘energy analyzer’ was developed in collaboration with Rauschert GmbH – a manufacturer of advanced ceramic products that require energy-intensive production processes. The research project was funded by the Bavarian Ministry of Economic Affairs, Infrastructure, Transport and Technology as part of its microsystems technology program.

Until recently, large-scale industrial energy users in Germany have benefited from reduced tax rates on the electricity and gas they consume. Now the German government has decided that companies will only be eligible for such tax breaks if they take steps to reduce their energy consumption. From 2013 onward, tax rebates will only be granted to companies equipped with an energy management system that provides details of their power consumption. This won’t be an easy task for the companies concerned, because it means they will have to install individual auxiliary meters to monitor the power consumption of individual loads such as presses and welding machines, or bakers’ ovens, or electric motors. And in many cases the metering instruments currently available on the market are too large to fit into existing power distribution cabinets.

The new device is based on the HallinOne 3-D magnetic field sensor originally developed by IIS for use in Bosch and Siemens branded washing machines, where it monitors the position and orientation of the rotating drum.

“This new device is the first application in which we have used our 3-D magnetic-field sensor technology to measure the magnetic field generated by an electric current as a means of determining the energy consumed by the connected load. As such, it is an entirely novel approach,” said IIS research scientist Michael Hackner. To build the device, he and his team of qualified engineers mounted eight sensors, in the form of application-specific integrated circuits (ASICs), on a flexible, flat circuit board. What sets these sensors apart from more conventional designs is that they measure the magnetic field not only perpendicular to the surface of the