Fluke 1773 Three-Phase Power Quality Analyzer

IEC 61000-4-30 defines measurement methods for 50 Hz and 60 Hz power quality instruments. Power Standards Lab was deeply involved in developing this standard, and continues to guide its on-going revisions and updates. This standard ensures that different PQ instruments use the same definitions, and measurement techniques, for various power quality parameters: sags/dips, swells, frequency, harmonics, flicker, etc. Older, non-compliant instruments may use their own definitions. As a result, two non-compliant instruments may produce very different readings for the same event. 1) The IEC 61000-4-30 defines the method of measurement and interpretation of results for Power Quality parameters in single and 3 phase 50/60Hz power supply systems around the world. 2) Power Quality parameters in this standard include: - Power frequency - Supply voltage - Unbalance magnitude of supply voltage - Voltage and current harmonics - Flicker - Interharmonics - Supply voltage - Dips and swells - Rapid voltage changes - Voltage interruptions mains signalling transient voltages (as a guide) 3) A Class A instrument within the specification will measure voltage and current to 0.1% accuracy. It also defines how a Class A instrument will calculate parameters from the measured data. 4) Accuracy will depend on method of measurement and must be made across contiguous 10 cycle periods (at 50Hz) i.e. a 200msec window. Longer term measurements are based on aggregates of each 10 cycle measurement for 3 seconds, 10 minutes and 2 hours. 5) Any instrument conforming to the IEC 61000-4-30 Class A, regardless of manufacturer will read the same when subjected to the same waveforms. 6) Voltage dips and swells and interruption durations must be based on one cycle RMS measurements calculated in half cycle steps. 7) The standard calls for Harmonics Measurements to IEC61000-4-7 (Year 2000 release) which again calls for ‘gapless’ 10 cycle determinations. 8) The

IEC 61000-4-7 is applicable to instrumentation intended for measuring spectral components in the frequency range up to 9 kHz which are superimposed on the fundamental of the power supply systems at 50 Hz and 60 Hz. For practical considerations, IEC 61000-4-7 distinguishes between harmonics, interharmonics and other components above the harmonic frequency range, up to 9 kHz. IEC 61000-4-7 defines the measurement instrumentation intended for testing individual items of equipment in accordance with emission limits given in certain standards (for example, harmonic current limits as given in IEC 61000-3-2) as well as for the measurement of harmonic currents and voltages in actual supply systems. Instrumentation for measurements above the harmonic frequency range, up to 9 kHz is tentatively defined.