Since the early Nineties Dranetz’ Dranview 7 software has had a built-in feature to process the measured harmonics against the limits set in G5/4 from the Electricity Association. This recommendation has now been released as G5/5 by the Energy Networks Association, which now demands that limits to the 100th Harmonic are considered. This level of harmonic was already acceptable to the HDPQ family of Power Quality Instruments as they could already measure to the 127th Voltage Harmonic.
Dranetz have matched this requirement with a new report that has the new limits pre-programmed, into it. These are set depending on the Voltage level being monitored: 0-400V, 400-25kV, 25kV-66kV etc. The report produces a tabulated result that can quickly and easily be incorporated into a Word or pdf document.
Rate of Change of Frequency (ROCOF)
To assist with G59/G99 testing it is useful to see the Rate of Change of Frequency to assist with synchronising the ‘raw’ mains or other secondary voltage input. Using the Maths function within the Dranview 7 it is now possible to plot ROCOF so as to ascertain exactly what is occurring as the frequency slews.
For more information on this software and the Dranetz range of portable and fixed Power Quality Analysers contact:
IMH Technologies Ltd
8 Roach View
Purdeys Industrial Estate
Essex, SS4 1LB