On 7/8/05, Peter wrote: > > > On Fri, 8 Jul 2005, Chen Xiao Fan wrote: > > > No. If you read the article you will know that Rogowski coil > > will not work very well at high frequency (say a few KHz). It > > is okay for the energy meter application that the author > > was addressing but not for the PFC and APF application. > > > > I was involved in a project of 1kW 3-phase multilevel universal > > PFC/APF/VAR-compensator (based on One-Cycle Control) research > > project and we used LEM exclusively for the phase current measurement > > and the switching frequency is more than 50kHz. > > Afaik Rogowski coils are used to measure and scope the pulses in kA and > nanosecond ranges. Peter, aren't you just a little bit too optimistic ? Compute what it means 1kA variation (let's be humans, 0.1kA it's enough) in 1nS. Then think where may appear such variation into the real world. A Rogowski coil can be configured as an unshielded > untwisted pair transmission line, terminated properly, and wound > edgewise on the conductor to be analyzed. The result is more or less > like a directional coupler with several windings. Afaik it has no upper > frequency limit at all. Again, optimistic. Adapting is never an ideal concept. That's why the VSWR was defined. best wishes, Vasile > Peter > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist