AS/NZS 61000.4.7:1999

1 - AS/NZS 61000.4.7:1999 ELECTROMAGNETIC COMPATIBILITY (EMC) - TESTING AND MEASUREMENT TECHNIQUES-GENERAL GUIDE ON HARMONICS AND
4 - PREFACE
6 - CONTENTS
9 - 1 Scope
9 - 2 Normative references
10 - 3 Definitions, symbols and indices
10 - 3.1 voltage
10 - 3.2 current
10 - 3.3 definitions related to harmonics:
11 - 3.4 interharmonics:
11 - 3.5 frequency-domain instrumentation:
11 - 3.6 time-domain instrumentation:
11 - 3.7 Symbols
11 - 3.8 Indices
12 - 4 General classification of instrumentation
12 - 4.1 Characteristics of the signal to be measured
13 - 4.2 Accuracy classes of instrumentation
13 - 4.3 Types of measurement
13 - 5 Common requirements for all types of instrumentation
13 - 5.1 Requirements for input circuits
13 - 5.1.1 Voltage input circuit
14 - 5.1.2 Current input circuit
15 - 5.2 Accuracy requirements for instruments
15 - 5.3 Accuracy requirements for external voltage- and current-transformers
17 - 6 Special requirements for frequency-domain instrumentation
17 - 6.1 General
17 - 6.2 Quasi-stationary harmonics
18 - 6.3 Fluctuating harmonics
18 - 6.4 Rapidly changing harmonics
18 - 6.5 Output requirements
18 - 7 Special requirements for time-domain instrumentation
18 - 7.1 Fast Fourier Transform (FFT) instrumentation - General concepts
20 - 7.1.1 Quasi-stationary harmonics
20 - 7.1.2 Fluctuating and rapidly changing harmonics
21 - 7.2 Digital filters
21 - 7. 3 Operation-mode and output requirements
22 - 8 Evaluation methods
22 - 8.1 Output signal filtering
22 - 8.1.1 Low-pass filter for frequency-domain instruments
22 - 8.1.2 Filter for time-domain instruments
23 - 8.2 Future methods
23 - 9 Voltage harmonic surveys in supply systems
23 - 9.1 Types of measurement equipment
23 - 9.2 Window- width and basic requirements for FFT- instrumentation
24 - 9.3 Time ranges for statistical handling of measured values
25 - 9.3.1 Very-short-time interval (first integrating time range)
25 - 9.3.2 Short-time interval (second integrating time range)
25 - 9.3.3 Long-time interval (third integrating time range)
26 - 9.3.4 Day interval (24 h)
26 - 9.3.5 Week or longer interval
26 - 10 Special cases of measurement
27 - 10.1 Phase-angle measurement
28 - 10.2 Distortion measurements
28 - 10.2.1 Distortion factors
29 - 10.2.2 Psophometric weighting
29 - 10.3 Symmetrical components measurement
30 - 10.4 Interharmonics measurement
31 - 11 Effect of environment - Immunity tests
31 - 11.1 Temperature and humidity
32 - 11.2 Instrument supply voltage
32 - 11.3 Common mode interference voltage
32 - 11.4 Static electricity discharges
32 - 11.5 Electromagnetic fields
37 - Annex A - Bibliography
38 - Annex ZZ - List of variations to IEC 61000-4-7:1991 for application in Australia and New Zealand

Provides guidance on the instrumentation intended for measuring voltage or current components with frequencies in the range of d.c. to 2500 Hz which are superimposed on the voltage or current at the power supply frequency. The Standard also provides guidance on measurement instrumentation intended for testing individual items of equipment in accordance with emission limits given in Standards as well as for the measurement of harmonic voltages and currents in actual supply systems. Frequency domain and time domain instrumentation are both considered in this Standard. This Standard is technically equivalent to and has been reproduced from IEC 61000-4-7:1991.

This guide is applicable to instrumentation intended for measuring voltage or current components with frequencies in the range of d.c. to 2 500 Hz which are superimposed on the voltage or current at the power supply frequency. This guide is also applicable to measurement instrumentation intended for testing individual items of equipment in accordance with emission limits given in standards (e.g. harmonic current limits as given in IEC 555-2) as well as for the measurement of harmonic voltages and currents in actual supply systems. The survey of harmonics in the power supply systems is of particular concern. The test procedure for measurements and test conditions for emission testing are not dealt with in this guide; these requirements are included in the particular standards. Harmonics of the supply frequency are of special concern but components at other frequencies (interharmonic components) may also have to be measured. Frequency-domain and time-domain instrumentation are both considered in this guide. Tentative recommendations are also given for the statistical analysis of harmonic measurements in the supply in order to make the comparison of results easier.For fluctuating and rapidly changing harmonics, a distinction is made between the measurement process itself with its relatively small time constant, and the evaluation process which handles the measurement data in a defined manner in order to compare the results with stated limits, acceptance or reference values.

First published as AS/NZS 61000.4.7:1999.