Relevant standards when considering power quality

Emissions and immission as a basis for power quality

Figure 1: Principle of electromagnetic compatibility. Consideration of the limits for emissions of interference and immunity (source: EN 61000-2-2, Annex A).

Network quality is not a new topic, although it has come more and more into focus in recent years due to an increasingly high-tech and also more vulnerable world. The consideration and the limits for the electrical phenomena are derived from the standardisation for electromagnetic compatibility of IEC 61000-x-x.

Emission = interference emission (A)
Immission = interference compatibility (B)

Since it is impossible either to prevent all power quality disturbances or to make all equipment completely immune to these disturbances, limits for emission of disturbances and for immunity are agreed. This is an established principle in the subject area of electromagnetic compatibility, which takes into account aspects of technical feasibility and economic efficiency.

Consideration and assessment in the electrical network

Statistical power quality evaluations are used to prove required conformities or identify possible problems on a statistical basis.

Assessment of the quality of an electrical network

  • IEC 61000-2-2
    Environmental conditions – Compatibility level for low-frequency conducted disturbances and signal transmission in public low-voltage networks (measurement takes place at the PCC – Point of Common Coupling)
  • IEC 61000-2-4
    Environmental conditions – compatibility level for low-frequency conducted disturbances in industrial installations (for industrial and non-public 50 / 60 Hz LV and MV AC networks up to 35 kV) 3 environmental classes (measurement at PCC, internal connection points)
  • IEC 61000-2-12
    Ambient conditions – Compatibility level for low-frequency conducted disturbances and signal transmission in public medium-voltage networks (measurement at the PCC)

Characteristics of voltage in electrical (public) supply networks

  • EN 50160
    Characteristics of the voltage in public LV, MV and HV supply networks (measurement at the PCC)
  • GB/T
    Guobiao standards or GB standards are the Chinese national standards. Recommended standards are prefixed with “GB / T”.
  • IEEE519
    Recommended practices and requirements for harmonic control in power installations (USA, etc.)
  • Country specific
    Country-specific forms of reporting can also exist for the above standards.
  • Application specific
    Based on the above standards, individual statistical reporting forms can also exist.

DACHCZ

The DACHCZ establishes technical rules for the assessment of grid feedback. As can already be seen from the wording, various countries participate in this rule as editors:

  • Forum Network Technology/Network Operation in the VDE (FNN)
    Bismarckstraße 33, D-10625 Berlin
  • The Austrian E-Economy Academy GmbH
    Brahmsplatz 3, A-1040 Wien
  • VSE – Association of Swiss Electricity Companies
    Hintere Bahnhofstrasse 10, CH-5001 Aarau
  • CSRES – Ceské sdruzení regulovanych elektroenergetickych spolecnosti
    Na hroude 19, CZ–14000 Praha 2

Assessment of the quality of an electrical network in the data centre

  • At the point of common coupling strong,
    IEC 61000-2-2, IEC 61000-2-4, IEC 61000-2-12, EN50160, IEEE519, GB/T, etc.
  • Voltage quality, non-utility provided supply in the data centre
    EN50600-2-2:2019-08 [Kapitel 6.2.3 Spannungsqualität]

Assessment to EN50600-2-2:2019-08 [Kapitel 6.2.3 Spannungsqualität] also complies with the principle of DSPQ a, [Demand Side Power Quality]to IEC TR 63191.

Attention

A statistical minimum period of 7 days should not be underrun when generating the ratings. However, especially in the case of mobile measurements, it is often demanded for various reasons to limit the minimum period to an hourly or even minute basis. It must be clear that this cannot result in any meaningful evaluation – let alone one that conforms to the law. As a rule, the assessments are issued in a report form. Whereby the format of the report is not subject to any standard.