When it comes to measuring alternating current (AC), few devices offer the user-friendliness and accuracy of Rogowski coils. These rope-style current transformers (CTs) are able to encircle a live conductor, such as a current-carrying cable, without disturbing it and determine the output current. Also known as flexible core coils, Rogowski coils offer a number of unique benefits and possible applications.

What is a Rogowski Coil?

Rogowski coils consists of evenly wound coils whose wire returns to the starting point along the central axis and the two ends are typically connected to a cable. Shaped like a donut or toroid, these electrical devices are unique in that their coil turns are wound around a non-magnetic air core, rather than an iron core – common in traditional current transformers.

Outperform Traditional Current Transformers

Rogowski coils offer a number of advantages over other types of current transformers, including conventional split core and clamp-on CTs. Topping the list of benefits is unparalleled usability, made possible by a handful of user-friendly features. Light weight design, large window size, and mechanical flexibility for mounting in small spaces help streamline installation allow for easy placement around bundled cables as well as irregularly shaped conductors. Not to mention that these unique coils require minimal current for calibration and can measure a wide range of currents. Because Rogowski coils have much smaller power loss than conventional CTs, they provide excellent energy savings and reduced lifecycle costs.

Additional benefits of Rogowski coils include:

Non-intrusive to the live conductor (Rogowski coils snap around the live conductor being tested)
Low inductance, meaning that it can respond rapidly (within nanoseconds) to changes in currents
Excellent linearity (Rogowski coils have no magnetic materials to saturate)
No risk of secondary winding opening
Easy temperature compensation
No need for increased secondary turns to keep a constant current output)
Rogowski Coil Applications

Rogowski Coils can easily replace conventional CTs for protection, metering, and control and have been applied at all voltage levels (low, medium, and high voltage). They have also been utilized for both indoor and outdoor installations. Because the basic Rogowski coil design can easily cover a wide range of real-world applications, the number of product variations on the market today are relatively small. As a result, consumers avoid confusing customizations and frequently enjoy lower costs and shorter delivery times.

As a result of their many benefits, Rogowski coils have a large number of applications including current monitoring in:

Precision welding systems
Arc melting furnaces
Electromagnetic launchers
Electric power transmission
Pulsed power
They can also be used in short-circuit testing of electric generators, motor protection systems, measuring harmonic current content, and as sensors in protection systems of electrical plants.

Interested in learning more about the benefits of Rogowski Coils? Contact a consultant at (303) 772-9100 or explore the multiple models available in Magnelab’s selection of Rogowski Coils. After all, Magnelab is the largest US manufacturer of Rogowski coil current sensors.

Topics: Products, Rogowski Coils