New Rogowski Coil Design with a High dV/dt Immunity and High Bandwidth

• Published in: EPE Journal Vol. 25; no. 1; pp. 22 - 27
• Main Authors: Hain, Stefan, Bakran, Mark-M.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.03.2015
• ISSN: 0939-8368; 2376-9319
• DOI: 10.1080/09398368.2015.11782458

With the fast development of modern power semiconductors in the last years, the development of current measurement technologies has to adapt to this evolution. The challenge for the power electronic engineer is to provide a current sensor with a high bandwidth and a high immunity against external interferences. Rogowski current transducers are popular for monitoring transient currents in power electronic applications. But the trend of even higher current and voltage gradients generates a dilemma regarding the Rogowski current transducer technology. On the one hand, a high current gradient requires a current sensor with a high bandwidth. On the other hand, high voltage gradients forces to use a shielding around the Rogowski coil in order to protect the measurement signal from a capacitive displacement current caused by an unavoidable capacitive coupling to the setup, which reduces the bandwidth substantially. This paper presents a new Rogowski coil design which allows measuring high current gradients close to high voltage gradients without interferences and without reducing the bandwidth by a shielding. With this new measurement technique, it is possible to solve the mentioned dilemma and to get ready to measure the current of modern power semiconductors such as SiC and GaN with a Rogowski current transducer.