Value chain · CLM-0789
In plain terms
A UK inverter-based generator must stay connected through a complete loss of grid voltage lasting up to 140 milliseconds, then get back to at least 90 per cent of its output within half a second, and must remain stable for up to 30 minutes afterwards.
The claim as recorded
The GB Grid Code fault ride-through requirement for a Power Park Module, at ECC.6.3.15, has two modes: Mode A covers the first 140 ms of three-phase, phase to phase, two-phase to earth or single-phase to earth faults, through which the module must remain transiently stable and connected for all Supergrid phase voltages down to a minimum of 0 per cent while generating the maximum possible reactive current without exceeding its transient rating, and must restore active power to at least 90 per cent of the pre-fault available level within 0.5 seconds of voltage recovery to 90 per cent of nominal; Mode B covers the period beyond 140 ms, through which active power must be maintained at least in proportion to the retained balanced Supergrid voltage with the same 90 per cent recovery within 1 second; modification GC-0141 additionally requires the module to stay connected and remain stable for up to 30 minutes following a fault-ride-through event; and the requirements apply to all faults on the 275 kV or 400 kV National Electricity Transmission System.
Scope and limits
System operator guidance, not the Grid Code text. Figure ECC.6.3.15.9(b), which sets the Mode B duration envelope, was not obtained when this record was written; it is read at the render in CLM-1108 (2026-09-19), and the longest dip the line requires a Power Park Module to ride through is 3 minutes at 85 per cent of nominal, or 2.5 s at 80 per cent. This establishes what the code requires; it establishes nothing about whether any rectenna design can meet it. CONFIRMED AGAINST THE CLAUSE TEXT 2026-09-15, WHICH IS NOW HELD AS SRC-452. ECC.6.3.15 carries "140ms in duration" verbatim - 61 occurrences of that token across the pack - and the Mode A duty reads "shall remain transiently stable and connected to the System without tripping ... for a close-up solid three-phase short circuit fault or any unbalanced short circuit fault on the Onshore Transmission System". The claim read the requirement correctly through the guidance, which is worth recording as plainly as the case where it did not: see CLM-0783, where the same guidance flattened a type-dependent clause set and this register inherited the flattening.
What it assumes
That the guidance faithfully summarises ECC.6.3.15; the guidance itself gives the Grid Code precedence in any dispute. Note also the guidance's own modal mixture: the Mode A reactive-current duty is written with "should" while the connection and recovery duties are written with "must", and the Grid Code text was not obtained to check whether that distinction is in the code or is an artefact of the summary. For the duties beyond 140 ms the code answers it: ECC.6.3.15.9.2.1(b) introduces duties (i) to (iv) with "shall" (SRC-452 PDF p.256, read at the render 2026-09-19); the 140 ms case in ECC.6.3.15.8 was not re-read.
Where it comes from
Scope, verbatim: "The Grid Code 'fault ride through' requirements apply to all faults on the 275kV or 400kV National Electricity Transmission System. The requirements vary depending on the type of fault and the Supergrid voltage profile (duration of fault or voltage dip)." Mode A definition, verbatim: "'Mode A' refers to the first 140msec of three-phase, phase to phase, two-phase to earth or single-phase to earth faults." Mode A duty, verbatim: "Throughout this period the Power Park Module is required to remain transiently stable and connected for all Supergrid phase voltages down to a minimum of 0%. It should also generate the maximum possible reactive current without exceeding the transient rating limit of the Power Park Module or any constituent element." Mode A recovery, verbatim: "Within 0.5 seconds, following fault clearance and restoration of the Supergrid voltage to at least 90% of nominal, the Power Park Module must restore the Active Power output to at least 90% of the level available immediately before the fault." Mode B duty, verbatim: "Throughout this period the Power Park Module is required to remain transiently stable and connected. It must maintain Active Power at least in proportion to the retained balanced Supergrid Voltage and generate the maximum possible reactive current without exceeding the transient rating limit of the Power Park Module or any constituent element." Mode B recovery, verbatim: "Within 1 second, following fault clearance and restoration of the Supergrid voltage to at least 90% of nominal, the Power Park Module must restore the Active Power output to at least 90% of the level available immediately before the fault." Thirty-minute clause, verbatim, stated once under each mode: "GC-0141 has added the requirement that the Power Park Module stay connected and remain stable for up to 30min, following a fault-ride-through event."
Basis: Grid Code ECC.6.3.15 as summarised by the system operator's compliance guidance; applies to faults on the 275 kV or 400 kV National Electricity Transmission System
Related records
- Answers question
- QST-012 not published in this release
Cite this
energyaperture.com/c/clm-0789
CLM-0789, Energy Aperture, as of 2024-06.
Connected records
Other published records linked to this one. A list, not a judgement.