Rogowski current probes target next-gen power semiconductors

The company will highlight the latest CWT MiniHF, demonstrating how this AC probe not only provides better common mode immunity to local high voltage transients, but also provides a more precise measurement delay which can be compensated for to give improved power loss measurement in power semiconductors using SiC technology for example.

Combining a novel shielding technique, utilising a low sensitivity coil and patented low-noise signal-conditioning circuitry, the CWT MiniHF wide-band screened probe boosts immunity to local dV/dt transients while maintaining small size, flexibility, and 3dB bandwidth of up to 30MHz for a 100mm coil. The probes feature a coil only 4.5mm thick with 5kV insulation voltage, and can handle maximum current slope of 100kA/µs.

As engineers increasingly need the enhanced noise immunity of a screened probe for measuring complex current waveforms in equipment such as UPS circuits, switched-mode power supplies and variable-speed drive inverters where high power density leads to high field strengths, or where the high speeds and high blocking voltages of SiC devices call for higher probe bandwidth and better common-mode immunity.

The wide-band screened CWT MiniHF probe eliminate the extra bulk and bandwidth restrictions imposed by conventional screening techniques, while delivering the known advantages of a Rogowski coil. These include zero insertion impedance, freedom from flying leads, isolated measurement, high peak-current rating, and the ability to measure small AC currents in the presence of large DC current.

Joanne Aberdeen, Director of Engineering, PEM, will also be delivering a vendor presentation on Wednesday 20th May 2015 at 2:40 to 3:00pm on The Practicalities of Measuring Fast Switching/Transient Currents in Power Electronic Applications Using Rogowski Transducers.