Value chain · CLM-0787
In plain terms
The UK harmonic planning levels for networks above 230 kV set total waveform distortion at 3 per cent, with the largest single-harmonic level being 2 per cent at the fifth and seventh harmonics. These are levels for the network as a whole, and each connection gets only a share of them. The document is a recommendation, and it is careful to say which of its words are mandatory.
The claim as recorded
ENA Engineering Recommendation G5 Issue 5, in effect for connection offers from 1 March 2020, sets for UK supply systems above 230 kV nominal a total harmonic voltage distortion planning level of 3 per cent of the fundamental and individual harmonic voltage planning levels of 2.0 per cent at the 5th and 7th, 1.5 per cent at the 3rd, 11th and 13th, 1.2 per cent at the 17th, 1.0 per cent at the 2nd and 19th, 0.8 per cent at the 4th and 23rd, 0.5 per cent at the 6th and 9th, 0.4 per cent at the 8th and 10th, 0.3 per cent at the 15th, 0.2 per cent at the 12th and above even and 21st and above odd multiples of three, and 0.6(25/h) + 0.2 for orders at or above the 25th; the document is an engineering recommendation whose own foreword reserves "shall" and "must" for mandatory requirements and uses "should" for a recommendation, and it describes its staged assessment procedure as recommended.
Scope and limits
These are PLANNING levels for the network, not emission limits for one connection. G5/5 sets a connection's own limits by apportioning headroom in its Stage 3 procedure, so no single connection is entitled to the whole planning level. Compatibility levels, in Tables 7 to 12, are a different and higher set and must not be confused with these. The copy read was obtained from dcode.org.uk rather than from the ENA.
What it assumes
That a 2 GW rectenna connects above 230 kV, which follows from SRC-240's statement that Grid Code fault ride-through applies to faults on the 275 kV or 400 kV National Electricity Transmission System, and from the retained RfG type D threshold at 110 kV and above.
Where it comes from
Effective date and normative language, verbatim, Foreword: "This Engineering Recommendation (EREC) is published by the Energy Networks Association (ENA) and comes into effect for connection offers issued by NOs to their customer from 01 March, 2020 or earlier if mutually agreed by both parties." Verbatim: "Where the term 'shall' or 'must' is used in this document it means the requirement is mandatory. The term 'should' is used to express a recommendation. The term 'may' is used to express permission." Recommended status of the procedure, verbatim, Introduction: "Clause 6 describes the recommended staged approach to assessing the connection of non-linear and/or resonant plant and equipment to supply systems." Obligation route, verbatim, Introduction, quoting the Electromagnetic Compatibility Regulations 2016: "A fixed installation must be installed applying good engineering practices and respecting the information on the intended use of its components". Table 1, "THDV planning levels at supply system PCC nominal operating voltage", row "V > 230": THDV = 3. Table 6, "Planning levels for harmonic voltages above 230 kV", odd non-multiple of 3: h=5, 2.0; h=7, 2.0; h=11, 1.5; h=13, 1.5; h=17, 1.2; h=19, 1.0; h=23, 0.8; h>=25, 0.6(25/h) + 0.2. Odd multiples of 3: h=3, 1.5; h=9, 0.5; h=15, 0.3; h>=21, 0.2. Even: h=2, 1.0; h=4, 0.8; h=6, 0.5; h=8, 0.4; h=10, 0.4; h>=12, 0.2. Note 3 to Table 1, verbatim: "% h = 1 means 'as a percentage of the voltage at the fundamental frequency'."
Basis: harmonic voltage planning levels as a percentage of the voltage at the fundamental frequency, at the supply system point of common coupling, for nominal voltage above 230 kV
Related records
- Answers question
- QST-012 not published in this release
Cite this
energyaperture.com/c/clm-0787
CLM-0787, Energy Aperture, as of 2020-03-01.
Connected records
Other published records linked to this one. A list, not a judgement.