New Industry Products

Current Probe Offers High-Bandwidth and High Interference Immunity

May 02, 2019 by Paul Shepard

Power Electronic Measurements (PEM UK) Ltd. has launched the new CWTHF current probe offering higher frequency operation and improved E-field immunity. Clip-on Rogowski current probes provide a convenient, wide-bandwidth and accurate means of measuring alternating currents.

The CWTHF is the latest addition to the company's CWT range and these new wideband probes use a novel electrostatic shielded Rogowski coil to provide excellent immunity to interference from fast local dV/dt transients or large 50/60Hz voltages.

The new CWTHF offers the ability to measure faster current transient rise-times, achieving a high frequency (-3dB) bandwidth of up to 30MHz for a 300mm coil and can handle a maximum current slope of over 100kA/µs. The CWTHF probes feature a robust coil of 8.5mm thickness with a 10kV peak insulation voltage.

This current probe is designed for a wide variety of applications, including power electronics development work in today's demanding noisy high-speed applications, EMC and power quality measurement in motor drives and traction, pulsed power measurements and even lightning strike current measurements.

The CWT is available in current ratings from 30A to 300kA, with coil circumferences of 300 to 1000mm as standard and longer available on request.

To compliment this new product introduction, Dr Chris Hewson will be presenting an Exhibitor Seminar during PCIM Europe 2019 on 'Delay, rise-time and slew rate using high frequency optimized CWTHF Rogowski current sensors in Power Electronics', on Thursday, 9th May 2019 at 10.40am. This presentation will cover, the improvements in bandwidth of PEM’s new CWTHF ranges of Rogowski current sensors and how this has opened-up new application areas including measurements in SiC semiconductors. Understanding the limitations of high frequency bandwidth and how this relates in practice to rise-time, slew rate and delay of these new faster probes is discussed and illustrated with practical measurement examples.