LEM offers two versions of the OLCI high-current sensors: the FRS model for primary busbar openings of 104mm x 22mm and the FL model for openings up to 300mm x 100mm. As a split transducer, the FL can be opened and connected directly to any point on the busbar without needing to open it, simplifying installation and maintenance.
The sustainability credentials of the new sensors stem from their 85% lower energy consumption compared to similar closed-loop sensors, resulting in savings of up to 150 kWh per year. The FRS sensor, which features no magnetic core or secondary copper winding, an integrated Rogowski coil, and a Hall element array, cuts raw material costs and reduces power losses. The simple busbar design and assembly decrease the number of devices required, and both sensors are made from 100% recyclable material at the end of their life cycle. Furthermore, thanks to LEM's short local supply chains in Europe and 100% recyclable packaging, the sensors' overall carbon footprint is minimized from a transportation and delivery perspective.
The new sensors, ideally suited for trackside and onboard applications in the railway sector, can also be used in wind turbines and hydrogen electrolyzers, as well as in low- and medium-voltage industrial frequency converters, induction welding applications, and DC network monitoring.
Key advantages of LEM's two new sensors include excellent accuracy and high signal integrity, with an output current of 4mA to 20mA. The Hall effect elements ensure lower temperature drift, reduced electrical offset, and less noise compared to open-loop alternatives. Other advantages include a fast response time due to the elimination of any low-pass filtering effect from eddy currents in the magnetic core.
The new sensors withstand high dI/dt and high-frequency content, and their coreless design allows them to maintain accuracy and functionality even under overcurrent conditions. Their unipolar power supply also reduces system power consumption and costs compared to traditional bipolar power supplies.
“Renewable energy and increasing electrification are the future for a more sustainable world, and LEM has kept this in mind by applying its expertise to the design of these coreless, high-current sensors,” said Thomas Hargé, Vice President of Product Management at LEM. “The FRS and FL sensors represent a major step forward for sustainability in industrial and rail applications, and will provide new technical solutions to the many challenges we need to overcome when developing systems and making the most of renewable energy.”.
