Drives and Controls Magazine

Box feeds motor braking energy back to the grid

29 August, 2008

The Scunthorpe, UK–based maintenance consultancy CP Automation has teamed up with a German electrotechnology specialist, Eltroplan Revcon, to offer a product that returns energy to the electricity network when a motor slows down.


The RevCon system (above) is designed to work with any AC drive and is claimed to be more cost-effective than using two inverters to achieve the same effect. It incorporates a harmonic filter, ensuring that the electricity returned to the network is G5/4-compliant. Users can charge the electricity supplier for the returned power using a feed-in tariff, similar to those that apply to small wind turbines.

CP Automation director Tony Young says that the wind turbine analogy is useful for highlighting the performance of the RevCon. "A wind turbine isn`t particularly effective, normally operating at about 40% efficiency," he says. "By contrast, when a motor slows down and begins to generate electricity, RevCon will operate at around 90% efficiency.

"The bottom line for most businesses is the commercial imperative, and this is where the product really comes into its own," he adds. "The cost savings can be quite extensive in a facility where there are several motors controlling manufacturing equipment, lifts and the like."

CP says that there are several projects in the UK already planning to install the RevCon system.