
What is a Rogowski coil?
A Rogowski coil, named after Walter Rogowski, is an electrical device for measuring alternating current (AC) or very fast current pulses. It consists of a spiral coil of wire, one end of which is usually routed back through the core to the beginning for easy connection on one side. There is no metal (iron) core. The winding density, the diameter of the coil, and the stiffness of the winding are crucial for maintaining immunity to external fields and low sensitivity to the positioning of the conductor in which the current is to be measured.
Since the voltage induced in the coil is proportional to the rate of change (derivative) of the current in the straight conductor, the output of the Rogowski coil is usually connected to an electrical (or electronic) integrator circuit to provide an output signal that is proportional to the current. Single-chip signal processors with built-in analogue to digital converters are often used for this purpose.
They are used in conditions similar to those of current transformers, but for many applications, they offer more advantages:
•
Groot meetbereik
•
Hoge lineariteit
•
Zeer nuttig bij grote of onhandige geleiders of op
plaatsen met beperkte toegang. Dankzij de structuur zonder harde kern kan de
spoel gemakkelijk worden geproduceerd op basis van de toepassing of de
beschikbare ruimte
•
In tegenstelling tot traditionele
stroomtransformatoren is er geen gevaar voor secundaire open circuits.
•
Ze kunnen niet
worden beschadigd door sterke overbelasting.
•
Ze zijn
niet-intrusief. Ze worden niet gevoed door het hoofdcircuit dat de te meten
stroom transporteert.
•
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They are lightweight and can be hung on the measured conductor in some applications.
Use and selection of the right current transformer
The choice depends on the type of application you are dealing with: a machine, a retrofit on an existing switchboard, or the need for a solution that can also work well without inspection.
Master Chips has various models of current transformers in stock to combine with your network analyzers or to be connected to the energy meters managed by us.
Vaak wordt bij het meten van elektriciteitsverbruik de keuze van de stroomtransformator onderschat. Dit kan leiden tot ongemak tijdens de installatie door de operator, tot het introduceren van meetfouten die de energiemeting van onze energiemeter kunnen beïnvloeden. BNekijk onze catalogus voor meertechnische informatie over dit item.
We recommend the version with 333mV secondary for installations remote from the measuring instrument.