IEC 61000-4-7 pdf download

IEC 61000-4-7 pdf download Electromagnetic compatibility (EMC) – Part 4-7: Testing and measurement techniques – General guide on harmonics and interharmonics measurements and instrumentation, for power supply systems and equipment connected thereto
This part of lEC 61000 is applicable to instrumentation intended for measuring spectralcomponents in the frequency range up to 9 kHz which are superimposed on the fundamentalof the power supply systems at 50 Hz and 60 Hz.For practical considerations, this standarddistinguishes between harmonics， interharmonics and other components above the harmonicfrequency range, up to 9 kHz.
This standard defines the measurement instrumentation intended for testing individual itemsof equipment in accordance with emission limits given in certain standards (for example,harmonic current limits as given in lEC 61000-3-2) as well as for the measurement ofharmonic currents and voltages in actual supply systems. Instrumentation for measurementsabove the harmonic frequency range, up to 9 kHz is tentatively defined (see Annex B).
NOTE 1 This document deals in detail with instruments based on the discrete Fourier transform.
NOTE 2 The description of the functions and structure of the measuring instruments in this standard is veryexplicit and meant to be taken literally. This is due to the necessity of having reference instruments withreproducible results irrespective of the characteristics of the input signals.
NOTE 3 The instrument is defined to accommodate measurements of harmonics up to the 50th order.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
l IEC 60038,IEC standard voltages
IEC 60050-161，International Electrotechnical Vocabulary – Chapter 161: Electromagneticcompatibility
IEC 61000-2-2，Electromagnetic compatibility (EMC) – Part 2-2:Environment – Compatibilitylevels for low-frequency conducted disturbances and signalling in public low-voltage powersupply systems
IEC 61000-3-2,Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for harmoniccurrent emissions (equipment input current s16 A per phase)
IEC 61000-3-12，Electromagnetic compatibility (EMC) – Part 3-12: Limits – Limits forharmonic currents produced by equipment connected to public low-voltage systems with inputcurrent >16A and ≤75 A per phase
3 Definitions, symbols and indices
For the purposes of this part of IEC 61 000, the definitions given in IEC 60050-1 61 (IEV) and the following, apply.
3.1 Definitions related to frequency analysis
Notations: The following notations are used in the present guide for the Fourier series development because it is easier to measure phase angles by observations of the zero crossings: