New current transformers for electronic electricity meters


Hanau / Frankfurt, Germany — (METERING.COM) — August 27, 2008 – VACUUMSCHMELZE GmbH & Co. KG (VAC) will present its current transformers for use in electronic electricity meters at the 2008 Metering, Billing/CRM conference and exhibition, being held in Amsterdam, The Netherlands, from 22-24 September. Here VAC will debut its new cost-optimized solutions based on its nanocrystalline VITROPERM material.

Electronic electricity meters are increasing in popularity for many reasons, including changes in statutory framework regulations. The new meters are free of mechanical wear and tear, are suitable for remote reading and interconnection in networks, and are able to deal with multiple tariffs. The market offers a variety of solutions. Current transformer-based measurement delivers convincing advantages compared to the shunt and Rogowski methods, including galvanic separation and lower sensitivity to external alternating fields. Disadvantages of three-phase meters using the shunt method (measurement of current using low-ohm electrical resistance) include heat loss and lack of galvanic separation, while Rogowski coils require both an additional shielding against alternating current fields and numerical integration of ultra-low signals, a factor which impairs accurate measurement.

Combined-core current transformers, on the other hand, may register measurement errors of around 20 percent in specific occurrences of network loads generated by common household appliances. There are thus plentiful reasons in favor of VAC’s current transformers. In addition, VAC’s portfolio includes a range of added value designs, including current transformers with integrated primary bus bar, current transformers with shielding against external magnetic fields (high resistance to external influences), three-phase modules which simplify installation for current ranges between 6 and 60 amp, and more.