Germany (VDE-AR-N 4120, draft summary) — ride-through requirements

The HVRT, FRT envelopes a grid-scale battery must meet under Germany (VDE-AR-N 4120, draft summary), digitized breakpoint by breakpoint and checked against the clause it came from.

By Sergey Syrvachev — Director of Product Engineering, grid-scale BESS · 10+ GWh delivered

Applies to: both connections — Customer installations on the 110 kV high-voltage network, including storage (draft scope). Values read from an authorised reproduction of a paywalled standard.

Part of: the grid-code ride-through chart — compare this against 63 other standards in 42 countries.

What this is, and is not. A reading aid compiled from the clause cited below — not a compliance document. The primary text governs. Some values on this page are marked partial: the level is confirmed but at least one duration step could not be read directly from the source. Draft 2017-05; superseded by 4120:2018-11 and A1:2024-04.

Breakpoints

Times are seconds from the start of the disturbance. Voltage is per-unit of nominal; frequency in hertz. An LVRT curve is a lower boundary (stay connected while voltage is on or above it), an HVRT curve an upper boundary, and FRT gives the band between its High and Low boundaries. These are the boundaries, not the behaviour: what holding one demands of the converter — reactive current injection, thermal stress, protection timing — is stepped through in the LVRT / HVRT ride-through visual.

EventDutyBreakpointsStatus
high-voltage ride-through (HVRT)ride-through0.001s → 1.3 pu; 0.1s → 1.3 pu; 0.101s → 1.25 pu; 60s → 1.25 pu; 60.001s → 1.15 pupartial
frequency ride-through (FRT)ride-throughHigh: 0.1s → 51.5 Hz; 3600s → 51.5 Hz | Low: 0.1s → 47.5 Hz; 3600s → 47.5 Hzpartial

Where these values come from

  • HVRTFNN/VDE 'Summary of the draft VDE-AR-N 4120:2017-05' (Forum Netztechnik/Netzbetrieb im VDE, May 2017). READ THIS BEFORE USING THE NUMBERS: it is a summary of a DRAFT (E VDE-AR-N 4120), it states on its own first page that it 'does not cover all parts of the VDE-AR-N 4120 and is therefore not exhaustive' and is 'purely informative', and it has since been superseded twice — by VDE-AR-N 4120:2018-11 and amendment A1:2024-04. Values may have changed on publication. Slide 19 (Type 1 modules, upper limit curve) read together with slide 21, whose prose states the surge requirement is 'unchanged compared to AR-N-4120-2015 (after 60s to U=1.15)'. The 1.25 pu level is corroborated a third time by the protection table on slide 48, where the generating-unit setting is U>> 1.25 UNS at 0.1 s. Published because three statements in the document agree, not because the chart alone was legible. Low-voltage ride-through is deliberately not included for this code. The LVRT curves exist only as chart images here, and two earlier candidate readings were wrong in ways worth naming: 4110 and 4120 LVRT curves that were byte-identical across different voltage levels, which no real code does, and a 'high-voltage' curve that was really a VDN-2004 voltage-relay setting. That second substitution is visible in this very document, which prints the relay table beside the curves — the tables are crisp and the curves are images, so the legible thing gets digitised. Protection settings say when a plant MAY disconnect; a ride-through envelope says when it MUST NOT. Plotting LVRT needs VDE-AR-N 4120:2018-11 itself, ideally with A1:2024-04.
  • FRTFNN/VDE 'Summary of the draft VDE-AR-N 4120:2017-05' (Forum Netztechnik/Netzbetrieb im VDE, May 2017). READ THIS BEFORE USING THE NUMBERS: it is a summary of a DRAFT (E VDE-AR-N 4120), it states on its own first page that it 'does not cover all parts of the VDE-AR-N 4120 and is therefore not exhaustive' and is 'purely informative', and it has since been superseded twice — by VDE-AR-N 4120:2018-11 and amendment A1:2024-04. Values may have changed on publication. Slide 51, tabular: for VDE-AR-N 4120 (new), at or below 47.5 Hz isolation from the grid, between 47.5 and 51.5 Hz 'isolation not permitted', between 51.5 and 52.5 Hz isolation PERMITTED, and at 52.5 Hz isolation from the grid. Plotted here is the firm obligation only — the 47.5 to 51.5 Hz band, which carries no time limit. The 51.5 to 52.5 Hz shoulder is discretionary and is deliberately not drawn as a requirement. The matching generating-unit protection settings on the same slide are f< 47.5 Hz at 0.1 s, f> 51.5 Hz at up to 5 s, and f>> 52.5 Hz at 0.1 s. Low-voltage ride-through is deliberately not included for this code. The LVRT curves exist only as chart images here, and two earlier candidate readings were wrong in ways worth naming: 4110 and 4120 LVRT curves that were byte-identical across different voltage levels, which no real code does, and a 'high-voltage' curve that was really a VDN-2004 voltage-relay setting. That second substitution is visible in this very document, which prints the relay table beside the curves — the tables are crisp and the curves are images, so the legible thing gets digitised. Protection settings say when a plant MAY disconnect; a ride-through envelope says when it MUST NOT. Plotting LVRT needs VDE-AR-N 4120:2018-11 itself, ideally with A1:2024-04.

Any event not in the table above is not plotted for this code. Where an absence is itself the finding — a code that defines no high-voltage envelope, or one whose curves circulate under another country's name — it is recorded in the grid codes with no ride-through curve.

Last checked against the source document on .

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