LEM Introduces Shunt Isolatorin Traction Applications
LEM introduces the DI series/Shunt isolator to enable high-accuracy current measurements in rail traction applications. DI Series transducers measure to a high degree of precision the very small voltages developed across low-resistance ohmic shunts in the primary power conductors feeding rail traction motors, spanning ranges of 30 to 200mVRMS.
Featuring LEM’s patented insulating technology, the DI series has specifically been designed to enable rail-traction designers to meet the provisional EN 50463 standard for on-board energy monitoring. When used with a shunt Class 0.2 accuracy, the DI reaches the required Class 1R accuracy.
The DI can then be part of the measurement chain of any on-board energy meter, as a key element in the recording of energy consumed (or returned to the supply under regenerative braking), according to the standards set out in the provisional standard.
Coupled to a shunt used for current measurement, the DI provides necessary voltage insulation (withstanding 18.5kVRMS/ 50 Hz/ for 1 minute as insulation test voltage) that is essential due to the high-voltages met in vehicles that are supplied with energy from works up to 3000 V.
DIs can easily be added to any existing shunts already mounted into the application when insulated operation is necessary.
With a low current consumption of 20-25mA (plus the output current), a wide frequency bandwidth of 10kHz, LEM’s DI shunt isolator meets the demands of modern rail systems and fulfils all new EMC requirements. Other key features include a high level of partial discharge extinction voltage, adherence to safety standards, high quality and long life, together with low weight and flexible mechanical and electrical output to adapt to customer needs.
LEM designed and produces the DI transducer according to the requirements of the International Railway Industry (IRIS). The materials utilized ply with the fire and smoke requirements, which are mandatory in railway applications. The DI is CE marked and is supplied with a five-year warranty, as are all LEM railway transducers.