Hi All,
I find the Dranetz to be an excellent instrument, but I do not leave it connected continuously, only for a week or so for fault finding.
I suggest you contact Ian Murdock, who is their agent in this country for a demonstration of the platforms and remote devices if you want a permanent...
Try using a low pass filter inbetween the meter amd terminals. Is the DC link in good condition and if so, is the drive output clamped at 480 via a parameter.
Does anyone know how to minimise composite resonance, if there is not much chance of improving the AC end supply quality. The output of the converter supplies the shunt field of a DC motor, which oscillates over a narrow rpm bandwidth.
I have a similar problem, but only in one direction. The armature is supplied from a 12 pulse rectifying system and the field from a 6 pulse regulator. Moving the brush neutral 6mm against rotation cures the oscillation, but torque is reduced. Have you measured the supplies for harmonics...