Harmonics Analysis Option for PS 250 and PS2500
Our PowerSight Manager software will perform harmonic analysis of waveforms to the 50th harmonic and present the results as either a table, including RMS amplitude and phase angle, or graphically as a bar chart. Either presentation may be printed out for reports. THD of voltages and currents can be automatically calculated and added to the data log (using the advanced data logging feature) for later graphing and analysis. THD snapshots taken on PowerSight can be broken down into percent magnitudes (relative to the fundamental frequency) and displayed on the unit (using the “More” key). K factor measurements will be displayed by PSM when viewing tabular results.
One of the key areas of interest in analyzing power quality is harmonic analysis. A distorted current consists of a current of the fundamental frequency (usually 50Hz or 60Hz or 400Hz) and other currents at frequencies that are multiples of the fundamental. The heating effect of higher frequencies is much greater than for lower frequencies. Therefore, excessive harmonic currents can overheat cables or distribution transformers (K factor is a measurement of this effect). In addition, harmonic currents do not tend to fully cancel out, which can leave large currents flowing in a neutral cable, possibly beyond the rating of the cable. In most areas, utilities are under regulation to provide voltage with no more than a few per cent THD (total harmonic distortion).