What is fault ride-through (FRT) for a BESS?

Fault ride-through is a grid-code requirement that a battery energy storage system (or any inverter-based resource) stay connected and keep supporting the grid through a temporary voltage or frequency disturbance, instead of tripping offline. Ride-through is split into low-voltage ride-through (LVRT), high-voltage ride-through (HVRT), and frequency ride-through (FRT). Each is defined as a curve of the worst voltage or frequency the plant must survive versus how long it lasts.

What is the difference between LVRT, HVRT, and FRT?

LVRT (low-voltage ride-through) sets how deep a voltage sag — and for how long — the plant must ride through without disconnecting; the curve is a lower boundary. HVRT (high-voltage ride-through) sets how high a temporary overvoltage the plant must ride through; the curve is an upper boundary. FRT (frequency ride-through) sets the over- and under-frequency band the plant must stay connected within. Together they define the voltage-time and frequency-time envelope a grid-connected BESS must tolerate.

How do I read a ride-through curve?

The x-axis is the duration of the disturbance (fault-clearing time), usually on a log scale from milliseconds to minutes; the y-axis is voltage in per-unit (1.0 = nominal) or frequency in hertz. For LVRT the plant must stay connected as long as the voltage stays on or above the curve for that duration; for HVRT, on or below it; for FRT, between the high and low boundaries. Points outside the envelope permit the plant to disconnect.

What does IEEE 2800-2022 require for ride-through?

IEEE 2800-2022 is the US standard for interconnecting inverter-based resources at transmission level. Its voltage ride-through requires the resource to stay connected through deep sags (down to zero volts for a short window, then to progressively higher retained voltages as duration increases) and through temporary overvoltage up to about 1.2 pu, with a continuous band of 0.9–1.1 pu. Its frequency ride-through requires continuous operation across a wide band around nominal. Use the interactive chart above to compare its exact curve against other standards.

Does a grid-scale battery have to meet these ride-through curves?

Yes. Ride-through compliance is a connection condition for utility-scale BESS in almost every market — it is verified in the interconnection study, written into the connection agreement, and demonstrated during commissioning with model validation and, often, on-site testing. The exact curve depends on the grid code that governs the point of interconnection, which is why the applicable standard has to be pinned down early in a project.

Which grid code applies to my project?

It depends on the country, the voltage level of the connection (distribution, medium voltage, or transmission), and sometimes the plant size. A transmission-connected plant in Texas follows ERCOT and NERC PRC standards; a European plant follows its national implementation of the RfG framework — Spain’s Orden TED/749/2020, Terna’s Allegato A.79 in Italy, PSE’s Wymogi in Poland, the Netcode in the Netherlands, EirGrid’s grid code in Ireland or G99 in Great Britain — which is why this chart plots those national codes rather than a single RfG curve. The chart lets you overlay the candidate standards so the binding envelope is clear.

Grid-Code Ride-Through Curves: LVRT, HVRT & FRT

Overlay the low-voltage (LVRT), high-voltage (HVRT), and frequency (FRT) ride-through envelopes that grid-scale battery storage must meet — across 60+ grid codes in more than 40 countries, each curve checked point-by-point against the clause it came from. Pick an event type, select the standards that govern your point of interconnection, and read the binding voltage-time or frequency-time curve.

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

What this is, and is not. A reading aid for orientation and comparison, compiled from the clauses cited below — not a compliance document. The primary text governs; nothing here should go into an interconnection study, a protection setting or a compliance submission without reading it.

How these curves were checked. Every envelope was read from the grid code itself and then re-checked, point by point, against the clause, table or figure it came from — the citation sits beside each standard below and on hover in the chart. Where a value could not be confirmed from a current primary text, the series is marked partial or is not plotted at all, and the standards left out are named with the reason. This is a reference for orientation and comparison, not a substitute for the code that governs your point of interconnection: before design or compliance work, read the source document for your connection voltage, plant type and jurisdiction.

What fault ride-through means for a BESS

When a fault, switching event, or generation trip disturbs the grid, voltage and frequency swing away from nominal for a fraction of a second to a few minutes. A grid-connected battery must not add to the problem by tripping offline the instant it sees a disturbance. Ride-through requirements define exactly how far, and for how long, voltage or frequency can deviate while the plant is still obliged to stay connected and keep supporting the grid. They are among the first grid-code clauses that shape a project’s inverter selection, protection settings, and controls.

LVRT, HVRT and FRT — the three envelopes

Low-voltage ride-through (LVRT) sets how deep a voltage sag, and for how long, the plant must survive without disconnecting — the curve is a lower boundary, and many codes require zero-voltage ride-through for a short window. High-voltage ride-through (HVRT) sets how high a temporary overvoltage the plant must tolerate — an upper boundary, typically to about 1.2–1.3 pu. Frequency ride-through (FRT) sets the over- and under-frequency band the plant must stay within; because both 50 Hz and 60 Hz systems are shown, FRT curves appear as two clusters. Every curve is voltage or frequency versus the duration of the disturbance.

How to read the chart

The horizontal axis is the duration of the disturbance — fault-clearing time — usually on a logarithmic scale from a millisecond to minutes. The vertical axis is voltage in per-unit (1.0 pu is nominal) or frequency in hertz. The shaded band marks continuous operation (0.9–1.1 pu, or 59.5–60.5 / 49.5–50.5 Hz). For LVRT the plant must stay connected while voltage is on or above its curve; for HVRT, on or below; for FRT, between the high and low boundaries. Turn on the worst-case envelope to see the binding requirement across every standard you have selected — the single curve that satisfies all of them at once. Where several codes share an identical envelope, they are drawn as interleaved dashes on the same line and tagged ×N in the legend, so one selection never hides underneath another.

Standards & grid codes covered

Every envelope below was checked point-by-point against the clause, table or figure named beside it. Verified means the digitized values were read from a freely published, current primary text; partial means the shape is confirmed but at least one value could not be read directly from the source. Curves last checked against their source documents on 25 July 2026.

North America

California Rule 21 verified LVRT/HVRT/FRT · Distribution — Smart-inverter DER at the distribution PCC (PG&E tariff) PG&E Electric Rule 21, Sheet 196, Table Hh-2b 'Frequency Ride-Through Settings Table' (f>62.0 no RT; 61.2<f<=61.8 Mandatory Operation 299 s; 58.8<=f<=61.2 Continuous Infinite; 57.0<=f<58.8 Mandatory Operation 299 s; F<57.0 no RT), section Hh 'Smart Inverter Generating Facility Design and Operating Requirements for UL1741SB Inverters', Advice 7692-E effective August 29, 2025, Superseded values from SDG&E Rule 21 Sheet 124 Table Hh-2 (Advice 2860-E, effective July 5, 2016): f>62 no ride-through 0.16 s trip; 60.5<f<62 mandatory 299 s; 58.5<f<60.5 continuous; 57.0<f<58.5 mandatory 299 s; f<57.0 no ride-through 0.16 s trip. Cross-checked against IEEE 1547-2018 Table 18 shall-trip defaults (OF2 62.0/0.16 s, OF1 61.2/300 s, UF1 58.5/300 s, UF2 56.5/0.16 s) as reproduced in NERC Reliability Guideline 'BPS Reliability Perspectives on the Adoption of IEEE 1547-2018', March 2023, Table 1.3. PG&E Electric Rule 21 tariff (PDF) ↗
Canada (Alberta AESO) verified LVRT/HVRT/FRT · Transmission — Generating facilities on the Alberta transmission system (AIES) AESO ISO Rules Section 503.6, Appendix 1 'Trip Settings for Off-Nominal Frequency Protective Relays': High - '>=61.7 Instantaneous trip', '>=61.6 / 30', '>=60.6 / 180', '<60.6 Continuous operation'; Low - '<=57.0 Instantaneous trip', '<=57.3 / 0.75', '<=57.8 / 7.5', '<=58.4 / 30', '<=59.4 / 180', '>59.4 Continuous operation'. Contrast IESO Market Rules Appendix 4.2 Issue 16.0 category 1 'Off-Nominal Frequency Operation'. AESO ISO Rules Section 503.5 (PDF) ↗
ERCOT (NOG 2.6.2.1) verified FRT · Transmission — Transmission-connected inverter-based resources in ERCOT ERCOT Nodal Operating Guides Section 2.6.2.1 'Frequency Ride-Through Requirements for Transmission-Connected Inverter-Based Resources (IBRs), Type 1 Wind-powered Generation Resources (WGRs) and Type 2 WGRs', paragraph (1) table (December 5, 2025 text, p. 32; carried in the February 1, 2026 Nodal Operating Guide): f > 61.8 Hz — may ride-through or trip; 61.6 < f ≤ 61.8 — 299 s; 61.2 < f ≤ 61.6 — 540 s; 58.8 ≤ f ≤ 61.2 — continuous; 58.4 ≤ f < 58.8 — 540 s; 57.0 ≤ f < 58.4 — 299 s; f < 57.0 — may ride-through or trip. ERCOT Nodal Operating Guides (PDF) ↗
ERCOT (NOG 2.9.1) verified LVRT/HVRT · Transmission — Transmission-connected IBRs: PVGRs and ESR IBRs (ERCOT) ERCOT Nodal Operating Guides, Section 2.9.1.1 'Preferred Voltage Ride-Through Requirements for Transmission-Connected Inverter-Based Resources (IBRs)', paragraph (1), Table B: Applicable to PhotoVoltaic Generation Resources (PVGRs) and ESR IBRs, plus the following paragraph defining the sub-0.25 pu straight-line function ('0.15 seconds at zero voltage and 1.75 seconds at 0.9 p.u. voltage'). Source: February 1, 2026 ERCOT Nodal Operating Guide PDF (body dated DECEMBER 5, 2025), sheet pp. 52-54. ERCOT Nodal Operating Guides (PDF) ↗
ERCOT (NOG 2.9.1.2 legacy) verified LVRT/HVRT · Transmission — Transmission IBR with SGIA executed before 1 Aug 2024 ERCOT Nodal Operating Guides Section 2.9.1.2 (applies where the SGIA was executed before 1 Aug 2024): V=0 to 0.15 s then the defined ramp V(t)=0.5625t-0.084375 reaching 0.90 pu at 1.75 s. ERCOT Nodal Operating Guides (PDF) ↗
IEEE 1547-2018 Cat III verified LVRT/HVRT/FRT · Distribution — DER at the distribution PCC, Category III abnormal performance · authorised reproduction IEEE 1547-2018 Table 16 / Figure H.4 ride-through capability regions, reproduced under IEEE copyright permission in EPRI's 'Crash Course: IEEE Std 1547-2018' (slide 47, 'Actual Abnormal Voltage Requirements for Category III'): momentary-cessation capability box 0.00–0.50 pu ending at 1 s; mandatory-operation capability 0.50–0.70 pu to 10 s and 0.70–0.88 pu to 20 s. Same regions in the MISO Guideline for IEEE Std 1547-2018 Implementation, Figure 4 (Category III), p.26. Independently confirmed in EPRI's reference implementation OpenDER (src/opender/operation_status/rt_crit.py, CAT_III branch): 0.7≤V<0.88 → pass at t>20 s; V<0.7 → t>10 s; V≤0.5 → t>1 s. Operating-mode bands also confirmed by the ISO-NE/Massachusetts TSRG 'Default IEEE 1547-2018 Setting Requirements' Table V (V<0.50 Momentary Cessation; 0.5≤V<0.88 Mandatory Operation; 'Identical' to 1547-2018 Cat III). NERC reliability guideline on IEEE 1547-2018 (PDF) ↗
IEEE 2800-2022 verified LVRT/HVRT/FRT · Transmission — IBR plants at the transmission point of interconnection · authorised reproduction IEEE 2800-2022 Clause 7.2.2.1 voltage ride-through table for 'plants without aux. load limitations' (solar/BESS), reproduced with IEEE copyright permission on slide 44 of the official IEEE PES / IEEE 2800 WG + SEIA/ACP joint webinar (31 May 2022): V>1.20 may trip; V>1.10 mandatory 1.0 s; V>1.05 continuous 1800 s; V<0.90 mandatory 6.00 s; V<0.70 3.00 s; V<0.50 1.20 s; V<0.25 0.32 s; V<0.10 permissive 0.32 s — with the step-curve plotted at 0.32/1.2/3.0/6.0 s. (slide 44; slide 43 is the wind table with 3.00/2.50/1.20/0.16/0.16). Independently corroborated by NERC PRC-029-1 Attachment 1 Table 2 ('All Other IBR' incl. PV+BESS: 6.00/3.00/1.20/0.32/0.32) and by the ERCOT NOGRR245 Voltage Ride-Through Capability Table ('Preferred Requirements … PVGR or ESR': 0.7 pu→6.0 s, 0.5→3.0, 0.25→1.2, 0→0.32). IEEE 2800 WG / SEIA-ACP webinar (authorised reproduction, PDF) ↗
Mexico (Codigo de Red) verified LVRT/HVRT/FRT · Both — Power plants interconnecting to the SEN (RNT or RGD) Codigo de Red, CRE Resolucion RES/550/2021, DOF 31 December 2021, pp.1068-1069; 'Manual Regulatorio de Requerimientos Tecnicos para la Interconexion de Centrales Electricas al Sistema Electrico Nacional', Capitulo 4, seccion 4.2.1, Tabla 4.2.1.B / Figura 4.2.1.B. Verified from the official DOF PDF (dof.gob.mx/2021/CRE/CRE_311221.pdf), text extracted directly.
NERC PRC-024-4 (ERCOT) verified FRT · Transmission — BES generator relay set points, ERCOT Interconnection NERC PRC-024-4, Attachment 1, Table 4 'Frequency Boundary Data Points – ERCOT Interconnection' and Figure 4 (p.15); identical to PRC-024-3 Table 4. NERC PRC-024-4 (PDF) ↗
NERC PRC-024-4 (Western) verified FRT · Transmission — BES generator relay set points, Western Interconnection NERC PRC-024-4, Attachment 1 '(Frequency No Trip Boundaries by Interconnection)', Table 2 'Frequency Boundary Data Points – Western Interconnection' and Figure 2 (p.13); identical to PRC-024-3 Table 2. NERC PRC-024-4 (PDF) ↗
NERC PRC-024-4 (no-trip) verified LVRT/HVRT · Transmission — BES generating resources; relay no-trip settings (GO duty) NERC PRC-024-4, Attachment 2 'Voltage No-Trip Boundaries – Eastern, Western, and ERCOT Interconnections', Table 5 'Voltage Boundary Data Points' (p.16) and Figure 5 callout. Identical table appears in PRC-024-3 (p.10, 'Voltage Boundary Data Points'), so the correction holds under either edition. NERC PRC-024-4 (PDF) ↗
NERC PRC-029-1 (IBR) verified LVRT/HVRT/FRT · Transmission — BES inverter-based resources; valid for RoCoF <= 5 Hz/s NERC PRC-029-1, Attachment 2 'Frequency Ride-Through Criteria', Table 3 'Frequency Ride-through Capability Requirements' and Figure 1 'PRC-029 Frequency Ride-through Requirements' (p.14); Requirement R3 caps applicability at RoCoF ≤ 5 Hz/s. NERC PRC-029-1 (PDF) ↗
NERC PRC-029-1 (Table 1: AC-connected wind IBR /…) verified LVRT · Transmission — AC-connected wind IBR on the BES (per Attachment 1 note 1) NERC Reliability Standard PRC-029-1, Attachment 1, Table 1 ("Voltage Ride-through Requirements for AC-Connected Wind IBR"), p.12; applicability per Attachment 1 note 1. FERC Order No. 909, RM25-3-000; effective 1 Oct 2026. NERC PRC-029-1 (PDF) ↗
Ontario (IESO Market Rules App. 4.2) verified FRT · Transmission — Generation and storage on the IESO-controlled grid IESO Renewed Market Rules, Chapter 4 'Grid Connection Requirements - Appendices', Library Record No. RUL-12, Issue 2.0, Effective December 3, 2025; Appendix 4.2, Category 1 'Off-Nominal Frequency Operation' - continuous 59.4-60.6 Hz, plus the log-linear regions bounded by (0.0 s, 57.0 Hz), (3.3 s, 57.0 Hz), (300 s, 59.0 Hz) and by (0.0 s, 61.8 Hz), (8 s, 61.8 Hz), (600 s, 60.6 Hz). Boundary is a continuous log-linear ramp; the plotted staircase is a conservative inner approximation of it. IESO Market Rules Chapter 4 ↗
Quebec (Hydro-Quebec D-2022-088) verified LVRT/HVRT/FRT · Transmission — Generating stations on the Hydro-Quebec transmission system Hydro-Quebec TransEnergie, 'Technical Requirements for the Connection of Generating Stations to the Hydro-Quebec Transmission System', Decision D-2022-088, effective July 15, 2022; section 12.2.1, Table 8 (p.48) and Figure 6 (p.49). Verified from the Hydro-Quebec-hosted English PDF (Exigences_raccordement_centrales_ang_2022-07-15.pdf), text extracted directly.
Transient overvoltage (IEEE 2800 TOV) verified HVRT · Transmission — IBR at transmission and sub-transmission (IEEE 2800 scope) · authorised reproduction IEEE 2800-2022 Table 14 (transient overvoltage ride-through), reproduced with IEEE copyright permission on slide 48 of the official IEEE PES / IEEE 2800 WG + SEIA/ACP joint webinar: 'V > 1.80 — see footnote a (surge protection); V > 1.70 — 0.2 ms; V > 1.60 — 1.0 ms; V > 1.40 — 3.0 ms; V > 1.20 — 15.0 ms', footnote c 'specified voltage magnitudes are the residual voltages with surge arresters applied', footnote d 'cumulative time over a 1-min time window', axis label 'Voltage at RPA (per unit of nominal instantaneous peak base)'. Clause text quoted in P. Pourbeik (PEACE/Invenergy), 'Thoughts on IEEE 2800-2022 TOV Ride-Through Requirement', ERCOT IBRWG 14 Jun 2024. Independently corroborated by the ERCOT NOGRR245 capability form, whose TOV rows are footnoted '*These requirements are from IEEE 2800-2022': 1.8 pu → 0.0002 s, 1.7 → 0.001 s, 1.6 → 0.003 s, 1.4 → 0.015 s. IEEE 2800 WG / SEIA-ACP webinar (authorised reproduction, PDF) ↗

Europe

Austria (E-Control TOR Typ D) verified LVRT/FRT · Transmission — Type D non-synchronous PGM, >=110 kV or >=50 MW E-Control, 'TOR Stromerzeugungsanlagen: Anschluss und Parallelbetrieb von Stromerzeugungsanlagen des Typs D' (Maximalkapazitat >= 50 MW oder Nennspannung >= 110 kV), Version 1.3, gultig ab 01.07.2024 - Kapitel 5.2.1, Abbildung 12 (FRT-Profil nichtsynchroner Stromerzeugungsanlagen, Anschluss auf oder oberhalb der 110-kV-Ebene), p. 28.
Belgium (Federal Grid Code) verified LVRT/FRT · Transmission — Type D power park modules on the federal transmission grid Koninklijk besluit / Arrete royal van 29 november 2024 houdende een technisch reglement voor het beheer van het transmissienet van elektriciteit (Belgian Federal Grid Code), Art. 94 § 3 - power park module van het type D; consolidated text via ejustice numac 2024008672. Repeals KB 22.04.2019 per Art. 158.
Denmark (TR 3.3.1) verified LVRT/FRT · Both — Battery plants; cited tables are the transmission-connected rows Energinet Technical Regulation 3.3.1 – Revision 6, Tables 30/32/34/36 (normal frequency operating range, transmission-connected, DK1 and DK2: 47.5–48.5 or 47.5–48.0 / 30 min, 48.5–49.0 or 48.0–49.0 / 30 min, 49.0–51.0 unlimited, 51.0–51.5 / 30 min) and section 68(1)/69(1) proviso on 60 minutes below 49.00 Hz; protection settings f< 47.5 Hz / 200 ms and f> 51.5 Hz / 200 ms are separate trip settings.
Finland (Fingrid VJV2024) verified LVRT/HVRT/FRT · Both — Generating facilities, VJV size classes 1-4, any network level Fingrid, 'Grid Code Specifications for Power Generating Facilities VJV2024', unofficial English translation dated 15.1.2025 - section 10.3.3 'Overvoltage withstand capability', Figure 10.4 (p. 48), extended by section 10.5.5.
France (RTE) verified LVRT · Transmission — Type D power park modules connected to RTE (>=110 kV) RTE Documentation Technique de Référence, Chapitre 5, Article 5.1.1 (version 1.2, applicable 03/08/2020), §4.6.1, Figure 10 'Gabarit creux de tension unité PPM type D' (axes 0 / 150 / 1500 ms, 0 % / 85 % / 100 % Un); implements arrêté du 9 juin 2020 / Règlement (UE) 2016/631 art. 16.
Greece (ADMIE/IPTO RfG) verified LVRT/FRT · Both — PGMs types A-D under the Greek RfG general requirements Απόφαση ΡΑΕ 1165/2020 (ΦΕΚ Β' 3757, 07.09.2020), Άρθρο 13 §1(α) στοιχείο (i), Πίνακας 2 'Εύρη τιμών συχνότητας συστήματος και ελάχιστες χρονικές διάρκειες παραμονής σε λειτουργία'.
Ireland (EirGrid) verified LVRT · Both — Controllable wind farm power stations (WFPS) EirGrid Grid Code v6 (22 July 2015), clause WFPS1.4.1 and Figure WFPS1.1 'Fault Ride-Through Capability of Controllable WFPSs': heavy black boundary at 15% U/Un from 0 to 625 ms, rising linearly to 90% at 3000 ms; axis ticks 0, 150, 625, 3000 ms. Verified by rendering the figure page directly. EirGrid Grid Code (PDF) ↗
Italy (TERNA) verified LVRT/HVRT · Transmission — Storage plants connecting to the RTN (Terna Allegato A.79) Terna Allegato A.79 Rev. 00, Marzo 2023, §6.4 'Insensibilità alle variazioni di tensione', Fig. 1 'Caratteristica FRT per Impianti di Accumulo' and Tabella 1 'Parametri FRT' (tA = 200 ms; tB = 2 s / 2,8 s / 4 s); same values in the June 2022 consultation text (Tabella 2).
Netherlands (TenneT) verified LVRT · Transmission — Type D power park modules (RfG art. 16), >=110 kV Netcode elektriciteit (versie 23-12-2023), artikel implementing NLE RfG 16(3)(a)(i), lid 3: 'Uret is 0 pu; Uclear is Uret; Urec1 is Uclear; Urec2 is 0,85 pu; tclear is 0,25 s; trec1 is tclear; trec2 is trec1; trec3 is 3,0 s' (besluiten ACM/UIT/509776 en ACM/UIT/575492); type-B PPM values in artikel 3.17 lid 3.
Norway (Statnett NVF 2025) verified LVRT/FRT · Transmission — Type D power park modules, >=110 kV Statnett, 'NVF 2025 - Nasjonal veileder for funksjonskrav i kraftsystemet' (ref. 2024/2852), gjeldende fra 13.06.2025 - kapittel 14.6.1, Tabell 14-15 (column 'Type D >= 110 kV') and Figur 14-11, with conditions per Tabell 14-16.
Poland (PSE Wymogi 2025) verified LVRT · Transmission — Type D power park modules (RfG art. 16), >=110 kV PSE S.A., 'Wymogi ogolnego stosowania wynikajace z Rozporzadzenia Komisji (UE) 2016/631 (NC RfG) - Maj 2025 r.' (Wymogi 2025), approved by URE decision DRE.WKP.744.18.15.2024.WZ.MKo4 of 15.05.2025 - Art. 16(3)(a)(i), Table 12 + Figure 7 (power park modules, type D); identical set at Art. 16(3)(c), Table 14 for asymmetrical faults.
Romania (Transelectrica/ANRE storage norm) verified LVRT/FRT · Transmission — Category D electricity storage installations (RfG type D) Ordinul ANRE nr. 3/2023 din 18.01.2023 (MO Nr. 53/19.I.2023) — Art. 6 alin. (1) lit. a) + Tabelul 1 'Durata minimă în care IS trebuie să fie capabilă să rămână conectată la rețea (să producă, respectiv să consume energie electrică la o putere activă mai mică sau egală cu puterea nominală) pentru frecvențe care se abat de la valoarea nominală': 47,5–48,5 Hz minimum 30 de minute; 48,5–49 Hz minimum 30 de minute; 49–51 Hz nelimitat; 51,0–51,5 Hz 30 de minute.
Spain (P.O. 12.3) verified LVRT/HVRT · Generating modules + storage under Orden TED/749/2020 Anexo I Orden TED/749/2020, Anexo I, ap. 3.1.1 d) y Figura 16 (BOE-A-2020-8965, pág. 62432), still current after Orden TED/82/2026 which only rewrote ap. 3.1.1 b)/Figura 14 for modules <110 kV; legacy P.O. 12.3 Figura 4.1, BOE-A-2006-18485 (ree.es PO_resol_12.3_Respuesta_huecos_eolica.pdf).
Sweden (EIFS 2018:2) verified LVRT/FRT · Transmission — Type D power park modules under EIFS 2018:2 Energimarknadsinspektionens föreskrifter EIFS 2018:2, 3 kap. 1 § (allmänna krav för kraftproduktionsmodul av typ A, B, C och D): '30 minuter inom frekvensområde 47,5–48,5 Hz; 30 minuter inom frekvensområde 48,5–49,0 Hz; obegränsad inom frekvensområde 49,0–51,0 Hz; 30 minuter inom frekvensområde 51,0–51,5 Hz'.
Switzerland (Swissgrid CESS minimum requiremen…) partial LVRT · Transmission — Converter-based storage connecting to the Swiss transmission grid Swissgrid, 'Technical minimum requirements for the connection of converter-based energy storage systems' (CESS), Version 1.1 of 29 May 2026 - section 3.2.4, Figure 4 (p. 12), read together with section 4.1. Superseded/contrasted source: Swissgrid-VSE 'Transmission Code 2019 (TC-CH)', section 6.5.5, Figure 15, Type 2 curve (Uret2 = 5-15 % Uc, band not a value).
Switzerland (Swissgrid TC-CH 2019) verified FRT · Transmission — Generation and storage on the Swiss transmission grid Swissgrid / VSE, 'Transmission Code 2019 (TC-CH)', section 6.5.2, Figure 12 'Robustness against frequency or voltage fluctuations' (p. 47) and paragraph 6.5.2(7) - NOT section 6.5.4; corroborated for storage by Swissgrid CESS minimum requirements v1.1 (29.05.2026), section 4.1, Figure 6.
Turkey (TEİAŞ Şebeke Yönetmeliği Ek-18 verified LVRT/FRT · Transmission — Generation facilities connected to the TEIAS transmission system Elektrik Şebeke Yönetmeliği (EPDK/TEİAŞ), EK-18 §E.18.2 'ÜRETİM TESİSLERİNİN ARIZA SONRASI SİSTEME KATKISI' + Şekil E.18.1, as introduced by the amendment of 22.04.2017 (Resmî Gazete 30046) — verified in the official annex PDF resmigazete.gov.tr/eskiler/2017/04/20170422-8-1.pdf, p. 1.
UK G99 (Type A-C) verified LVRT/FRT · Distribution — Type A-C power park modules connected below 110 kV ENA EREC G99 Issue 2, 10 March 2025, Table 13.5 and Figure 13.10 'Voltage against time curve applicable to Type C and Type D Power Park Modules connected below 110 kV': Uret 0.1, Uclear 0.10, Urec1 0.10, Urec2 0.85; tclear 0.14, trec1 0.14, trec2 0.14, trec3 2.2 (figure axis extends to 180 s). Identical to Table 12.2 / Figure 12.6 for Type B PPMs. Type A: clause 11.3.1.
UK G99 (Type D) verified LVRT/FRT · Transmission — Type D power park modules connected at or above 110 kV ENA EREC G99 Issue 2, 10 March 2025, Table 13.6 and Figure 13.11 'Voltage against time curve applicable to Type D Power Park Modules connected at or above 110 kV': Uret 0, Uclear 0, Urec1 0, Urec2 0.85; tclear 0.14, trec1 0.14, trec2 0.14, trec3 2.2, figure axis to 180 s. Clause 13.3.1.1 makes the heavy black line of Figures 13.8-13.11 the ride-through boundary.

Asia-Pacific

Australia (NER / AEMO) partial LVRT/HVRT/FRT · Both — Registered generating systems at any NEM connection point NER S5.2.5.3 as substituted by item [173] of the ERC0393 final rule — automatic access standard, read with the S5.2.5.3 definitions: 'transient frequency limit' and 'transient frequency time' mean 47.5 Hz and 9 seconds respectively; 'stabilisation time' and 'recovery time' mean the longest times allowable for the frequency of the power system to remain outside the operational frequency tolerance band and the normal operating frequency band respectively. AEMC Reliability Panel, Frequency Operating Standard effective 9 October 2023, Table A.3 (mainland, interconnected system — protected event and multiple contingency event: containment band 47.0–52.0 Hz; stabilisation band 49.5–50.5 Hz within 2 minutes; recovery band 49.85–50.15 Hz within 10 minutes), read with the mainland operational frequency tolerance band 49.0–51.0 Hz and normal operating frequency band 49.85–50.15 Hz; Tables A.6/A.7 for Tasmania (47.0–55.0 Hz). National Electricity Rules, Chapter 5 (PDF) ↗
India (CEA Connectivity Regs) partial LVRT/HVRT/FRT · Transmission — Generating stations connecting to the Indian HV grid CEA Regulations Compendium, August 2024, Part II clause B2(2) (footnote: substituted vide Second amendment, 2019 w.e.f. 06.02.2019): 'capable of operating in the frequency range 47.5 to 52 Hz and be able to deliver rated output in the frequency range of 49.5 Hz to 50.5 Hz' — . Identical wording in the 2019 gazette:. CEA Regulations Compendium (PDF) ↗
Malaysia (Grid Code Additional Code 2025) verified LVRT/FRT · Transmission — PPMs and energy storage units on the Peninsular grid system Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 (Suruhanjaya Tenaga), Connection Code CC.6.4.15.2 and Figure 6 'Power Park Modules and Energy Storage Units Fault Ride Through Requirements'; definition of Energy Storage Unit; CC.6.2.4.1.
New Zealand (EIPC cl 8.25A) verified HVRT · Transmission — Generating stations connected to the grid, both islands Electricity Industry Participation Code 2010, Part 8, cl 8.25A(1) and (6), upper boundary of Figure 8.1 / Figure 8.2 — verified in the 1 May 2025 consolidation; clause unchanged at 1 July 2026.
New Zealand North Island (EIPC cl 8.19(1)) partial FRT · Transmission — Generating stations connected to the national grid, North Island Electricity Industry Participation Code 2010, Part 8, cl 8.19(1)(a)-(f), cl 8.19(3), cl 8.21(1), cl 8.1B — verified verbatim in both the 1 May 2025 and 1 July 2026 consolidations.
New Zealand North Island (EIPC cl 8.25A) verified LVRT · Transmission — Grid-connected generating stations, North Island (Fig 8.1) Electricity Industry Participation Code 2010, Part 8, cl 8.25A(1) and (6), Figure 8.1 — verified in the 1 May 2025 consolidation (ea.govt.nz/documents/7277); clause text unchanged in the 1 July 2026 consolidation (ea.govt.nz/documents/10397).
New Zealand South Island (EIPC cl 8.25A) verified LVRT · Transmission — Grid-connected generating stations, South Island (Fig 8.2) Electricity Industry Participation Code 2010, Part 8, cl 8.25A(1) and (6), Figure 8.2 — verified in the 1 May 2025 consolidation; clause unchanged at 1 July 2026.
Philippines PV (PGC 2016 Fig 4.4) verified LVRT · Transmission — Grid-connected PV plants (PGC applies to the Grid) Philippine Grid Code, 2016 Edition (ERC Resolution No. 22, Series of 2016), GCR 4.4.4.4.1(a)-(d) and Figure 4.4 'Low voltage withstand capability – PVS'.
Philippines VRE (PGC 2016 Tables 4.1 & 4.3) verified FRT · Transmission — Wind and PV plants connected to the transmission grid Philippine Grid Code, 2016 Edition, Table 4.1 under GCR 4.4.3.2 (Wind) and Table 4.3 under GCR 4.4.4.2 (PVS) — identical values; nominal system frequency 60 Hz.
Philippines Wind (PGC 2016 Fig 4.2) verified LVRT · Transmission — Grid-connected wind farms (PGC applies to the Grid) Philippine Grid Code, 2016 Edition (ERC Resolution No. 22, Series of 2016), GCR 4.4.3.4.1(a)-(c) and Figure 4.2 'Low Voltage withstand capability – Wind Farms'.
Singapore (EMA Transmission Code App. F6) partial FRT · Transmission — Generating units and ESS on the SG transmission system Energy Market Authority of Singapore, Transmission Code, 26 September 2024, Appendix F, section F6.1–F6.2 'Frequency Range of Generating Unit' (p.79): F6.1 normal 49.5–50.5 Hz, exceptional rise to 52 Hz / fall to 47 Hz; F6.2 table — '52 Hz – 47.5 Hz: Continuous operation is required'; '47.5 Hz – 47 Hz: Generating unit is required to remain in operation for at least 20 seconds each time frequency falls below 47.5Hz'. ESS definition in section 1.3; Appendix L3.
South Korea (KEPCO) partial LVRT/HVRT/FRT · Distribution — DER at the distribution PCC (LV up to 22.9 kV) KEPCO 분산형전원 배전계통 연계 기술기준 (개정 14, 2021-06-01), <표 2.8> 비정상 주파수에 대한 운전지속시간: f > 61.5 → '-'; f < 57.5 → 299초; f < 57.0 → '-'; and <표 2.5> 비정상 주파수에 대한 분산형전원 분리시간: f > 61.5 → 0.16초; f < 57.5 → 300초; f < 57.0 → 0.16초. High boundary is a single level (no over-frequency ride-through granted); low boundary floor 57.0 Hz is the bottom edge of the 299 s band.
Sri Lanka (CEB) verified LVRT/FRT · Transmission — Generators connecting to the CEB transmission grid Ceylon Electricity Board, Grid Connection Code, Grid Code - Revised September 2023 (PDF published July 2024, ceb.lk '1723552921Grid_Connection_Code_for_publishing_in_CEB_web.pdf'), section 3.17.3 'Fault Ride Through / Low Voltage Fault Ride Through (LVRT)', Figure 3.17-10 'Fault Ride Through requirement - Voltage duration curve' (p.32).
Taiwan (TPC) verified LVRT/HVRT/FRT · Both — ESS paralleled to Taipower LV, HV or EHV systems 台灣電力股份有限公司儲能系統併聯技術要點 (中華民國114年9月5日修正), clause (十) 故障持續運轉能力(頻率): 責任分界點頻率之正負百分之二點五範圍內 (58.5–61.5 Hz) 應能持續運轉; (十)1 低頻率持續運轉能力(LFRT) 附圖五 — '頻率介於 57.5 至 58.5Hz 時，持續運轉時間應至少 5 分鐘；頻率介於 57.0 至 57.5Hz 時，持續運轉時間應至少 20 秒'; (十)2 高頻率持續運轉能力(HFRT) 附圖六 — '頻率介於 61.5 至 62.0 Hz 時，持續運轉時間應至少 5 分鐘'. Taipower storage interconnection requirements (PDF) ↗
Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) verified LVRT/HVRT/FRT · Both — BESS connecting to the transmission or distribution system Circular 05/2025/TT-BCT dated 1 February 2025, Article 44 clause 3(a)-(c), as consolidated with Circular 46/2025/TT-BCT (in force 22 September 2025); identical envelope at Article 40 clause 6.

South America

Argentina (CAMMESA PT-4 Anexo I, Fig. Ai.1 verified LVRT/HVRT · Transmission — ERNC parks at SADI transmission nodes (figure example: 500 kV) CAMMESA, LOS PROCEDIMIENTOS – P.T.4, ANEXO I, numeral 9.8.3 'Tolerancia a huecos de tensión (LVRT)' items 1)–6) + Fig. Ai.1 'curva límite tensión-tiempo (LVRT – HVRT), Ejemplo para Parques ERNC vinculados a nodos de 500 kV' (p.48). Versión 03-Oct-2023.
Argentina (CAMMESA PT-4) verified FRT · Transmission — ERNC parks / generators joining the MEM-SADI grid CAMMESA, LOS PROCEDIMIENTOS – P.T.4, numeral 2.2.3.2 lit. b) 'Rangos de frecuencia admisibles de operación' (Pág. 6) + 'Curva límite frecuencia-tiempo / Zona Admisible' (Pág. 7); applied to ERNC parks by ANEXO I numeral 9.8.5. Versión 03-Oct-2023.
Brazil (PRODIST / ONS) verified LVRT/HVRT/FRT · Transmission — Generators connecting to Rede Basica transmission facilities ONS Submódulo 3.6 rev. 2019.08, Quadro 6 'Requisitos técnicos gerais' item 1 (Operação em regime de frequência não nominal), p. 21 — ALL five sub-items: (a) 'Desligamento instantâneo permitido para operação abaixo de 56 Hz.'; (b) 'Operação abaixo de 58,5 Hz por período de tempo mínimo de 20 segundos.'; (c) 'Operação entre 58,5 e 62,5 Hz por tempo ilimitado.'; (d) 'Operação acima de 62,5 Hz por período de tempo mínimo de 10 segundos.'; (e) 'Desligamento instantâneo permitido para operação acima de 63 Hz.' Summarised in Figura 1 'Faixas de operação da central geradora em regime de frequência não nominal'.
Chile (NTSyCS) verified LVRT/HVRT · Converter-based plants (GFM + GFL) connecting to the SEN CNE Anexo Tecnico 'Exigencias Minimas de Instalaciones Basadas en Convertidores que se Conecten al SEN' (Res. Ex. 45, 28-01-2026), Art. 3-1(i) + Figura 1 (IBR GFM) and Art. 4-1(b) + Figura 2 (IBR GFL): T0 = 0 ms, T1 = max fault-clearing time per Art. 5-40 NTSyCS, T2 = T1 + 20 ms, T3 = 1000 ms, recovery boundary 0.80 pu. NTSyCS Art. 5-40: 120 ms for >= 200 kV, 400 ms for < 200 kV. Same shape as the superseded NTSyCS Art. 3-7. CNE Anexo Técnico IBR, Res. Ex. 45 (PDF) ↗
Colombia (CREG 060/2019) verified LVRT/HVRT · Transmission — Wind + PV plants on the STN/STR, 500 kV excluded Resolución CREG 060 de 2019, Artículo 14 (modifica numeral 5.7 lit. c) del Código de Operación), figura 'Característica de LVRT y HVRT para plantas eólicas y solares fotovoltaicas con conexión a STN y STR (no incluye 500 kV)' — verified from the official embedded graphic resolucion_creg_0060_2019_obj_2.gif.
Colombia (CREG 060/2019, red de 500 kV) verified HVRT · Transmission — Wind + PV plants connected at 500 kV (STN) Resolución CREG 060 de 2019, Artículo 14 — numeral 5.7 lit. c) del Código de Operación; figura 'Característica de LVRT y HVRT para plantas eólicas y solares fotovoltaicas con conexión a nivel de 500 kV' (official graphic obj_3.gif).
Ecuador (ARCONEL-001/24 Código de Conexión) verified LVRT/FRT Regulación Nro. ARCONEL-001/24 «Código de Conexión del Sistema Eléctrico Ecuatoriano» (expedida por Resolución ARCONEL-003/2024, Sesión de Directorio de 04 de septiembre de 2024), numeral 22.2 lit. a) y Gráfico 8; banda de Tabla 8 (numeral 22.1 lit. a); categorías en Tabla 1.
Panama (Código de Redes Fotovoltaico 2017) partial LVRT/HVRT/FRT · PV plants connected to the national interconnected system (SIN) ASEP/CND Panamá, 'ANEXO B — CÓDIGO DE REDES FOTOVOLTAICO (Texto Unificado)', Diciembre 2017, numeral B.1.2 lit. c) y Figura B.1.2 (curva azul HVRT); continuous band from B.1.1 lit. a) / B.1.2 lit. b).
Peru (COES PR-20, Anexo 1 Cap. 4 verified LVRT/FRT · Transmission — Non-conventional RE plants and storage integrated into the SEIN Procedimiento Técnico del COES N° 20 (PR-20), Anexo 1, Capítulo 4, numeral 4.4.3 (viñeta 'Comportamiento Transitorio') y Figura 4.4 'Curva tensión-tiempo del sistema de protección de tensión por fase'; band from 4.4.6; extended to storage by 4.5.1. Aprobado por Res. Consejo Directivo Osinergmin N° 173-2024-OS/CD.

Africa

Kenya (KNTGC VRPP) verified LVRT/HVRT/FRT · Transmission — Variable renewable power plants at transmission connection Kenya National Transmission Grid Code (KNTGC), clause 7.2.3.1 'Fault Ride-through Requirements for VRPPs', Figure 7-2 'Voltage Must Remain Connected Area', Area B — verified against the KETRACO-published KNTGC Final 30-04-2021 (identical clause numbering and wording to the March-2024 edition cited).
Morocco (CRENT) partial HVRT/FRT · Transmission — Generation connected to the national transmission grid (CRENT) Maroc, Code du Reseau Electrique National de Transport (CRENT), Article 78 §3 'Tenue aux Variations de Frequence', published by ANRE (anre.ma/crent_chapitre/article-78/); CRENT in force since 3 January 2022.
Nigeria (TCN Grid Code) partial LVRT/HVRT/FRT · Transmission — Power Park Modules on the TCN transmission system The Grid Code for the Nigeria Electricity Transmission System, NERC, published 01-08-2018 (cover 'Version 03', page footers 'Version 02'), clause 12.6.9(a)-(c) and Figure 1 'Voltage Fault Ride Through requirement for Power Park Modules' (p.63); Vmin from Table 1, subsection 10.1.5 (p.47).
South Africa (NRS 097 / RPP) verified LVRT/HVRT/FRT · Both — RPP categories A3/B/C on transmission or distribution SA RPP Grid Code v3.1 (Jan 2022), clause 5.1(4) (RPP shall be capable of operating for the minimum operating range illustrated in Figures 1 and 2), 5.1(5) 'When the frequency on the NIPS is higher than 51.5 Hz for longer than 4 seconds, the RPP shall be disconnected from the grid' and 5.1(6) 'When the frequency on the NIPS is less than 47.0 Hz for longer than 200ms, the RPP may be disconnected'; Figure 2 'Minimum frequency operating range of a RPP (during a system frequency disturbance)' (p.13) — upper boundary steps at 4 s (52 -> 51.5) and 60 s (51.5 -> 51.0); lower boundary steps at 200 ms (-> 47), 6 s (47 -> 47.5), 10 s (47.5 -> 48) and 60 s (48 -> 49); continuous range 49.0-51.0 Hz.

Middle East

Saudi Arabia (SAGC) verified LVRT/HVRT/FRT · Transmission — Renewable generating units on the SA transmission network The Saudi Arabian Grid Code, 2nd Electronic Update Oct 2016, clause 2.5.5.21: 'The Renewable Resource Generating Unit shall remain connected to the Network and continue stable operation if none of the phases exceeds 120% of nominal voltage for more than 1s'; clause 2.5.5.20(b)(ii) upper-side wording and Figure 2.3; steady-state ceiling per 2.4.3 = 1.1 pu. Saudi Arabian Grid Code (PDF) ↗

What this chart deliberately does not plot

A missing curve costs a reader nothing; a wrong one can be designed against. These standards were researched and then left out, with the reason stated.

Germany — VDE-AR-N 4110 (MV) / 4120 (HV) Paywalled, with the limit curves published only as bitmaps. The candidate low-voltage curves for the two documents were byte-identical (not credible for different voltage levels), and the high-voltage candidate traced back to a legacy VDN-2004 voltage-relay setting rather than a ride-through envelope.
ENTSO-E RfG (Regulation (EU) 2016/631) RfG delegates every fault-ride-through parameter to each TSO within ranges (Arts. 14(3)(a) and 16(3)(a)), so there is no single "RfG curve" to plot. It also defines no high-voltage ride-through profile at all — Annex II Figure 3 is low-voltage only. The national implementations are plotted instead.
China — GB/T 36547-2024 Paywalled. The candidate curves matched neither the 2018 nor the 2024 edition (wrong plateau duration, missing steps), so nothing is plotted pending access to the standard.
Japan — utility interconnection requirements The candidate low-voltage curve matched no Japanese requirement, and the Japanese requirement set defines no over-voltage ride-through table.
Canada — IESO (Ontario) IESO publishes no numeric voltage ride-through envelope. Curves previously circulating under an "Ontario" label are in fact the Alberta AESO tables, which are plotted here under Alberta.
High-voltage ride-through for UK G99, Ireland, France and the Netherlands None of these codes defines a high-voltage ride-through voltage-vs-time envelope. RTE explicitly defers it to a future edition of the DTR. Only their low-voltage (and, for G99, frequency) requirements are plotted.
Saudi Arabia — SAGC low-voltage ride-through The candidate curve matched nothing in the code. Only the high-voltage clause, which states the duty in one sentence, is plotted.

Frequently asked

What is fault ride-through (FRT) for a BESS?: Fault ride-through is a grid-code requirement that a battery energy storage system (or any inverter-based resource) stay connected and keep supporting the grid through a temporary voltage or frequency disturbance, instead of tripping offline. Ride-through is split into low-voltage ride-through (LVRT), high-voltage ride-through (HVRT), and frequency ride-through (FRT). Each is defined as a curve of the worst voltage or frequency the plant must survive versus how long it lasts.
What is the difference between LVRT, HVRT, and FRT?: LVRT (low-voltage ride-through) sets how deep a voltage sag — and for how long — the plant must ride through without disconnecting; the curve is a lower boundary. HVRT (high-voltage ride-through) sets how high a temporary overvoltage the plant must ride through; the curve is an upper boundary. FRT (frequency ride-through) sets the over- and under-frequency band the plant must stay connected within. Together they define the voltage-time and frequency-time envelope a grid-connected BESS must tolerate.
How do I read a ride-through curve?: The x-axis is the duration of the disturbance (fault-clearing time), usually on a log scale from milliseconds to minutes; the y-axis is voltage in per-unit (1.0 = nominal) or frequency in hertz. For LVRT the plant must stay connected as long as the voltage stays on or above the curve for that duration; for HVRT, on or below it; for FRT, between the high and low boundaries. Points outside the envelope permit the plant to disconnect.
What does IEEE 2800-2022 require for ride-through?: IEEE 2800-2022 is the US standard for interconnecting inverter-based resources at transmission level. Its voltage ride-through requires the resource to stay connected through deep sags (down to zero volts for a short window, then to progressively higher retained voltages as duration increases) and through temporary overvoltage up to about 1.2 pu, with a continuous band of 0.9–1.1 pu. Its frequency ride-through requires continuous operation across a wide band around nominal. Use the interactive chart above to compare its exact curve against other standards.
Does a grid-scale battery have to meet these ride-through curves?: Yes. Ride-through compliance is a connection condition for utility-scale BESS in almost every market — it is verified in the interconnection study, written into the connection agreement, and demonstrated during commissioning with model validation and, often, on-site testing. The exact curve depends on the grid code that governs the point of interconnection, which is why the applicable standard has to be pinned down early in a project.
Which grid code applies to my project?: It depends on the country, the voltage level of the connection (distribution, medium voltage, or transmission), and sometimes the plant size. A transmission-connected plant in Texas follows ERCOT and NERC PRC standards; a European plant follows its national implementation of the RfG framework — Spain’s Orden TED/749/2020, Terna’s Allegato A.79 in Italy, PSE’s Wymogi in Poland, the Netcode in the Netherlands, EirGrid’s grid code in Ireland or G99 in Great Britain — which is why this chart plots those national codes rather than a single RfG curve. The chart lets you overlay the candidate standards so the binding envelope is clear.

Every plotted value

The complete dataset as text — 125 series, every breakpoint, so the numbers can be read, searched and cited without running the chart. Times are seconds from the start of the disturbance; voltage is per-unit of nominal, frequency in hertz.

Take the data: CSV — one row per breakpoint JSON — one object per series free to reuse under CC BY 4.0 with credit to BESS.engineer. Each row carries the clause it was read from, so a value can always be traced back to its source.

Standard	Event	Duty	Level	Breakpoints	Status
Argentina (CAMMESA PT-4) Argentina	FRT	ride-through	transmission	High: 0.1s → 52.5 Hz; 15s → 52.5 Hz; 15.001s → 52 Hz; 25s → 52 Hz; 25.001s → 51.5 Hz; 100s → 51.5 Hz; 100.001s → 51 Hz \| Low: 0.1s → 47.5 Hz; 15s → 47.5 Hz; 15.001s → 48 Hz; 25s → 48 Hz; 25.001s → 48.5 Hz; 100s → 48.5 Hz; 100.001s → 49 Hz	verified
Australia (NER / AEMO) Australia	FRT	ride-through	both	High: 0.1s → 52 Hz; 120s → 52 Hz; 120.001s → 51 Hz; 600s → 51 Hz; 600.001s → 50.15 Hz \| Low: 0.1s → 47 Hz; 120s → 47 Hz; 120.001s → 49 Hz; 600s → 49 Hz; 600.001s → 49.85 Hz	partial
Austria (E-Control TOR Typ D) Austria	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 3600s → 47.5 Hz; 3600s → 48.5 Hz; 9000s → 48.5 Hz; 9000s → 49 Hz	verified
Belgium (Federal Grid Code) Belgium	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 48.5 Hz; 3600s → 48.5 Hz; 3600s → 49 Hz	verified
Brazil (PRODIST / ONS) Brazil	FRT	ride-through	transmission	High: 0.1s → 63 Hz; 10s → 63 Hz; 10.001s → 62.5 Hz \| Low: 0.1s → 56 Hz; 20s → 56 Hz; 20.001s → 58.5 Hz	verified
California Rule 21 US	FRT	ride-through	distribution	High: 0.1s → 61.8 Hz; 299s → 61.8 Hz; 299.001s → 61.2 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 58.8 Hz	verified
Canada (Alberta AESO) Canada	FRT	ride-through	transmission	High: 0.1s → 61.7 Hz; 30s → 61.7 Hz; 30.001s → 61.6 Hz; 180s → 61.6 Hz; 180.001s → 60.6 Hz \| Low: 0.1s → 57 Hz; 0.75s → 57 Hz; 0.751s → 57.3 Hz; 7.5s → 57.3 Hz; 7.501s → 57.8 Hz; 30s → 57.8 Hz; 30.001s → 58.4 Hz; 180s → 58.4 Hz; 180.001s → 59.4 Hz	verified
Denmark (TR 3.3.1) Denmark	FRT	ride-through	both	High: 0.1s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 48.5 Hz; 3600s → 49 Hz	verified
ERCOT (NOG 2.6.2.1) US	FRT	ride-through	transmission	High: 0.1s → 61.8 Hz; 299s → 61.8 Hz; 299.001s → 61.6 Hz; 540s → 61.6 Hz; 540.001s → 61.2 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 58.4 Hz; 540s → 58.4 Hz; 540.001s → 58.8 Hz	verified
Ecuador (ARCONEL-001/24 Código de Conexión) Ecuador	FRT	ride-through	—	High: 0.1s → 63 Hz; 90s → 63 Hz; 90.001s → 62 Hz; 1800s → 62 Hz; 1800s → 61 Hz \| Low: 0.1s → 57.5 Hz; 90s → 57.5 Hz; 90.001s → 58 Hz; 1800s → 58 Hz; 1800s → 59 Hz	verified
Finland (Fingrid VJV2024) Finland	FRT	ride-through	both	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
Greece (ADMIE/IPTO RfG) Greece	FRT	ride-through	both	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
IEEE 1547-2018 Cat III US	FRT	ride-through	distribution	High: 0.1s → 61.8 Hz; 299s → 61.8 Hz; 299.001s → 61.2 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 58.8 Hz	verified
IEEE 2800-2022 US	FRT	ride-through	transmission	High: 0.1s → 61.8 Hz; 299s → 61.8 Hz; 299.001s → 61.2 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 58.8 Hz	verified
India (CEA Connectivity Regs) India	FRT	ride-through	transmission	High: 0.1s → 52 Hz \| Low: 0.1s → 47.5 Hz	partial
Kenya (KNTGC VRPP) Kenya	FRT	ride-through	transmission	High: 0.1s → 52 Hz; 4s → 52 Hz; 4.001s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz; 3600s → 51 Hz; 3600s → 50.5 Hz \| Low: 0.1s → 47 Hz; 20s → 47 Hz; 20.001s → 47.5 Hz; 180s → 47.5 Hz; 180.001s → 48 Hz; 1800s → 48 Hz; 1800s → 49 Hz; 3600s → 49 Hz; 3600s → 49.5 Hz	verified
Malaysia (Grid Code Additional Code 2025) Malaysia	FRT	ride-through	transmission	High: 0.1s → 52 Hz; 3600s → 52 Hz; 3600s → 51.5 Hz; 5400s → 51.5 Hz; 5400s → 50.5 Hz \| Low: 0.1s → 47 Hz; 10s → 47 Hz; 10.001s → 47.5 Hz; 5400s → 47.5 Hz; 5400s → 49.5 Hz	verified
Mexico (Codigo de Red) Mexico	FRT	ride-through	both	High: 0.1s → 62.4 Hz; 900s → 62.4 Hz; 900.001s → 61.8 Hz; 1800s → 61.8 Hz; 1800s → 61.2 Hz \| Low: 0.1s → 57 Hz; 900s → 57 Hz; 900.001s → 58.2 Hz; 1800s → 58.2 Hz; 1800s → 58.8 Hz	verified
Morocco (CRENT) Morocco	FRT	ride-through	transmission	High: 0.1s → 53 Hz; 10s → 53 Hz; 10.001s → 52 Hz \| Low: 0.1s → 46.5 Hz; 10s → 46.5 Hz; 10.001s → 47 Hz	verified
NERC PRC-024-4 (ERCOT) US	FRT	no-trip	transmission	High: 0.1s → 61.8 Hz; 30s → 61.8 Hz; 30.001s → 61.6 Hz; 540s → 61.6 Hz; 540.001s → 60.6 Hz \| Low: 0.1s → 57.5 Hz; 2s → 57.5 Hz; 2.001s → 58 Hz; 30s → 58 Hz; 30.001s → 58.4 Hz; 540s → 58.4 Hz; 540.001s → 59.4 Hz	verified
NERC PRC-024-4 (Western) US	FRT	no-trip	transmission	High: 0.1s → 61.7 Hz; 30s → 61.7 Hz; 30.001s → 61.6 Hz; 180s → 61.6 Hz; 180.001s → 60.6 Hz \| Low: 0.1s → 57 Hz; 0.75s → 57 Hz; 0.751s → 57.3 Hz; 7.5s → 57.3 Hz; 7.501s → 57.8 Hz; 30s → 57.8 Hz; 30.001s → 58.4 Hz; 180s → 58.4 Hz; 180.001s → 59.4 Hz	verified
NERC PRC-029-1 (IBR) US	FRT	ride-through	transmission	High: 0.1s → 61.8 Hz; 299s → 61.8 Hz; 299.001s → 61.2 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 58.8 Hz	verified
New Zealand North Island (EIPC cl 8.19(1)) New Zealand	FRT	ride-through	transmission	Low: 0.1s → 47 Hz; 0.101s → 47.1 Hz; 5s → 47.1 Hz; 5.001s → 47.3 Hz; 20s → 47.3 Hz; 20.001s → 47.5 Hz; 120s → 47.5 Hz	partial
Nigeria (TCN Grid Code) Nigeria	FRT	ride-through	transmission	High: 0.1s → 51.75 Hz; 15s → 51.75 Hz; 15.001s → 51.5 Hz \| Low: 0.1s → 47.5 Hz	partial
Norway (Statnett NVF 2025) Norway	FRT	ride-through	transmission	High: 0.1s → 52.5 Hz; 1800s → 52.5 Hz; 1800s → 51.5 Hz; 3600s → 51.5 Hz; 3600s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
Ontario (IESO Market Rules App. 4.2) Canada	FRT	ride-through	transmission	High: 0.1s → 61.8 Hz; 8s → 61.8 Hz; 8.001s → 61.5 Hz; 23.5s → 61.5 Hz; 23.501s → 61.2 Hz; 69s → 61.2 Hz; 69.001s → 60.9 Hz; 204s → 60.9 Hz; 204.001s → 60.6 Hz \| Low: 0.1s → 57 Hz; 3.3s → 57 Hz; 3.301s → 57.5 Hz; 10.2s → 57.5 Hz; 10.201s → 58 Hz; 31.5s → 58 Hz; 31.501s → 58.5 Hz; 97s → 58.5 Hz; 97.001s → 59 Hz; 300s → 59 Hz; 300.001s → 59.4 Hz	verified
Panama (Código de Redes Fotovoltaico 2017) Panama	FRT	ride-through	unclear	High: 0.1s → 61.7 Hz; 30s → 61.7 Hz; 30.001s → 61.5 Hz; 180s → 61.5 Hz; 180.001s → 60.5 Hz \| Low: 0.1s → 57.2 Hz; 0.75s → 57.2 Hz; 0.751s → 57.4 Hz; 7.5s → 57.4 Hz; 7.501s → 57.9 Hz; 30s → 57.9 Hz; 30.001s → 58.5 Hz; 180s → 58.5 Hz; 180.001s → 59.5 Hz	verified
Peru (COES PR-20, Anexo 1 Cap. 4 Peru	FRT	ride-through	transmission	High: 0.1s → 62 Hz; 30s → 62 Hz; 30.001s → 61.6 Hz; 1800s → 61.6 Hz; 1800s → 60.6 Hz \| Low: 0.1s → 57 Hz; 10s → 57 Hz; 10.001s → 57.8 Hz; 30s → 57.8 Hz; 30.001s → 58.4 Hz; 1800s → 58.4 Hz; 1800s → 59.4 Hz	verified
Philippines VRE (PGC 2016 Tables 4.1 & 4.3) Philippines	FRT	ride-through	transmission	High: 0.1s → 62.4 Hz; 300s → 62.4 Hz; 300.001s → 61.8 Hz \| Low: 0.1s → 57.6 Hz; 3600s → 57.6 Hz; 3600s → 58.2 Hz	verified
Quebec (Hydro-Quebec D-2022-088) Canada	FRT	ride-through	transmission	High: 0.1s → 61.7 Hz; 90s → 61.7 Hz; 90.001s → 61.5 Hz; 660s → 61.5 Hz; 660.001s → 60.6 Hz \| Low: 0.1s → 55.5 Hz; 0.35s → 55.5 Hz; 0.351s → 56.5 Hz; 2s → 56.5 Hz; 2.001s → 57 Hz; 10s → 57 Hz; 10.001s → 57.5 Hz; 90s → 57.5 Hz; 90.001s → 58.5 Hz; 660s → 58.5 Hz; 660.001s → 59.4 Hz	verified
Romania (Transelectrica/ANRE storage norm) Romania	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
Saudi Arabia (SAGC) Saudi Arabia	FRT	ride-through	transmission	High: 0.1s → 62.5 Hz; 30s → 62.5 Hz; 30.001s → 61.5 Hz; 1800s → 61.5 Hz; 1800s → 60.5 Hz \| Low: 0.1s → 57 Hz; 30s → 57 Hz; 30.001s → 57.5 Hz; 1800s → 57.5 Hz; 1800s → 58.8 Hz	verified
Singapore (EMA Transmission Code App. F6) Singapore	FRT	ride-through	transmission	High: 0.1s → 52 Hz; 3600s → 52 Hz \| Low: 0.1s → 47 Hz; 20s → 47 Hz; 20.001s → 47.5 Hz	partial
South Africa (NRS 097 / RPP) South Africa	FRT	ride-through	both	High: 0.2s → 52 Hz; 4s → 52 Hz; 4.001s → 51.5 Hz; 60s → 51.5 Hz; 60.001s → 51 Hz \| Low: 0.2s → 47 Hz; 6s → 47 Hz; 6.001s → 47.5 Hz; 10s → 47.5 Hz; 10.001s → 48 Hz; 60s → 48 Hz; 60.001s → 49 Hz	verified
South Korea (KEPCO) South Korea	FRT	ride-through	distribution	High: 0.1s → 61.5 Hz \| Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 57.5 Hz	partial
Sri Lanka (CEB) Sri Lanka	FRT	ride-through	transmission	High: 0.1s → 53 Hz; 20s → 53 Hz; 20.001s → 52 Hz; 1200s → 52 Hz; 1200s → 51.5 Hz; 5400s → 51.5 Hz; 5400s → 51 Hz \| Low: 0.1s → 47 Hz; 60s → 47 Hz; 60.001s → 47.5 Hz; 5400s → 47.5 Hz; 5400s → 49 Hz	verified
Sweden (EIFS 2018:2) Sweden	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
Switzerland (Swissgrid TC-CH 2019) Switzerland	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 49 Hz	verified
Taiwan (TPC) Taiwan	FRT	ride-through	both	High: 0.1s → 62 Hz; 300s → 62 Hz; 300.001s → 61.5 Hz \| Low: 0.1s → 57 Hz; 20s → 57 Hz; 20.001s → 57.5 Hz; 300s → 57.5 Hz; 300.001s → 58.5 Hz	verified
Turkey (TEİAŞ Şebeke Yönetmeliği Ek-18 Turkey	FRT	ride-through	transmission	High: 0.1s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 1800s → 47.5 Hz; 1800s → 48.5 Hz; 3600s → 48.5 Hz; 3600s → 49 Hz	verified
UK G99 (Type A-C) UK	FRT	ride-through	distribution	High: 0.1s → 52 Hz; 900s → 52 Hz; 900.001s → 51.5 Hz; 5400s → 51.5 Hz; 5400s → 51 Hz \| Low: 0.1s → 47 Hz; 20s → 47 Hz; 20.001s → 47.5 Hz; 5400s → 47.5 Hz; 5400s → 49 Hz	verified
UK G99 (Type D) UK	FRT	ride-through	transmission	High: 0.1s → 52 Hz; 900s → 52 Hz; 900.001s → 51.5 Hz; 5400s → 51.5 Hz; 5400s → 51 Hz \| Low: 0.1s → 47 Hz; 20s → 47 Hz; 20.001s → 47.5 Hz; 5400s → 47.5 Hz; 5400s → 49 Hz	verified
Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) Vietnam	FRT	ride-through	both	High: 0.1s → 52 Hz; 60s → 52 Hz; 60.001s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz \| Low: 0.1s → 47.5 Hz; 600s → 47.5 Hz; 600.001s → 48 Hz; 1800s → 48 Hz; 1800s → 49 Hz	verified
Argentina (CAMMESA PT-4 Anexo I, Fig. Ai.1 Argentina	HVRT	ride-through	transmission	0.001s → 1.2 pu; 0.12s → 1.2 pu; 0.121s → 1.1 pu; 1200s → 1.1 pu; 1200s → 1.05 pu	verified
Australia (NER / AEMO) Australia	HVRT	ride-through	both	0.001s → 1.3 pu; 0.2s → 1.3 pu; 0.201s → 1.25 pu; 2s → 1.25 pu; 2.001s → 1.2 pu; 20s → 1.2 pu; 20.001s → 1.15 pu; 1200s → 1.15 pu; 1200s → 1.1 pu	verified
Brazil (PRODIST / ONS) Brazil	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2.5s → 1.2 pu; 2.501s → 1.1 pu	verified
California Rule 21 US	HVRT	ride-through	distribution	0.001s → 1.2 pu; 12s → 1.2 pu; 12.001s → 1.1 pu	verified
Canada (Alberta AESO) Canada	HVRT	ride-through	transmission	0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.175 pu; 0.5s → 1.175 pu; 0.501s → 1.15 pu; 1s → 1.15 pu; 1.001s → 1.1 pu	verified
Chile (NTSyCS) Chile	HVRT	ride-through	unclear	0.001s → 1.2 pu; 1s → 1.2 pu; 1.001s → 1.1 pu	verified
Colombia (CREG 060/2019) Colombia	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu	verified
Colombia (CREG 060/2019, red de 500 kV) Colombia	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.05 pu	verified
ERCOT (NOG 2.9.1) US	HVRT	ride-through	transmission	0.001s → 1.2 pu; 1s → 1.2 pu; 1.001s → 1.1 pu	verified
ERCOT (NOG 2.9.1.2 legacy) US	HVRT	ride-through	transmission	0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.175 pu; 0.5s → 1.175 pu; 0.501s → 1.15 pu; 1s → 1.15 pu; 1.001s → 1.1 pu	verified
Finland (Fingrid VJV2024) Finland	HVRT	ride-through	both	0.001s → 1.2 pu; 5s → 1.2 pu; 5.001s → 1.1 pu	verified
IEEE 1547-2018 Cat III US	HVRT	ride-through	distribution	0.001s → 1.2 pu; 12s → 1.2 pu; 12.001s → 1.1 pu	verified
IEEE 2800-2022 US	HVRT	ride-through	transmission	0.001s → 1.2 pu; 1s → 1.2 pu; 1.001s → 1.1 pu	verified
India (CEA Connectivity Regs) India	HVRT	ride-through	transmission	0.001s → 1.3 pu; 0.2s → 1.3 pu; 0.201s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu	verified
Italy (TERNA) Italy	HVRT	ride-through	transmission	0.001s → 1.3 pu; 0.1s → 1.2 pu; 1s → 1.15 pu	verified
Kenya (KNTGC VRPP) Kenya	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu	verified
Mexico (Codigo de Red) Mexico	HVRT	ride-through	both	0.001s → 1.3 pu; 0.2s → 1.3 pu; 0.201s → 1.1 pu	verified
Morocco (CRENT) Morocco	HVRT	ride-through	transmission	0.001s → 1.2 pu; 20s → 1.2 pu; 20.001s → 1.15 pu	partial
NERC PRC-024-4 (no-trip) US	HVRT	no-trip	transmission	0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.175 pu; 0.5s → 1.175 pu; 0.501s → 1.15 pu; 1s → 1.15 pu; 1.001s → 1.1 pu	verified
NERC PRC-029-1 (IBR) US	HVRT	ride-through	transmission	0.001s → 1.2 pu; 1s → 1.2 pu; 1.001s → 1.1 pu; 1800s → 1.1 pu; 1800s → 1.05 pu	verified
New Zealand (EIPC cl 8.25A) New Zealand	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.15 pu; 6s → 1.15 pu; 6.001s → 1.1 pu	verified
Nigeria (TCN Grid Code) Nigeria	HVRT	ride-through	transmission	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu	partial
Panama (Código de Redes Fotovoltaico 2017) Panama	HVRT	ride-through	unclear	0.001s → 1.2 pu; 2.2s → 1.2 pu; 2.201s → 1.1 pu	partial
Quebec (Hydro-Quebec D-2022-088) Canada	HVRT	ride-through	transmission	0.001s → 1.4 pu; 0.1s → 1.4 pu; 0.101s → 1.25 pu; 2s → 1.25 pu; 2.001s → 1.2 pu; 30s → 1.2 pu; 30.001s → 1.15 pu; 300s → 1.15 pu; 300.001s → 1.1 pu	verified
Saudi Arabia (SAGC) Saudi Arabia	HVRT	ride-through	transmission	0.001s → 1.2 pu; 1s → 1.2 pu; 1.001s → 1.1 pu	verified
South Africa (NRS 097 / RPP) South Africa	HVRT	ride-through	both	0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu	verified
South Korea (KEPCO) South Korea	HVRT	ride-through	distribution	0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.1 pu	verified
Spain (P.O. 12.3) Spain	HVRT	ride-through	unclear	0.001s → 1.2 pu; 0.05s → 1.2 pu; 0.24s → 1.19 pu; 0.43s → 1.18 pu; 0.62s → 1.17 pu; 0.81s → 1.16 pu; 1s → 1.15 pu	verified
Taiwan (TPC) Taiwan	HVRT	ride-through	both	0.001s → 1.2 pu; 0.25s → 1.2 pu; 0.251s → 1.15 pu; 1s → 1.15 pu; 1.001s → 1.1 pu	verified
Transient overvoltage (IEEE 2800 TOV) US	HVRT	ride-through	transmission	0.0001s → 1.8 pu; 0.0002s → 1.8 pu; 0.00021s → 1.7 pu; 0.001s → 1.7 pu; 0.00101s → 1.6 pu; 0.003s → 1.6 pu; 0.00301s → 1.4 pu; 0.015s → 1.4 pu; 0.0151s → 1.2 pu	verified
Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) Vietnam	HVRT	ride-through	both	0.001s → 1.2 pu; 0.5s → 1.2 pu; 0.501s → 1.15 pu; 3s → 1.15 pu; 3.001s → 1.1 pu	verified
Argentina (CAMMESA PT-4 Anexo I, Fig. Ai.1 Argentina	LVRT	ride-through	transmission	0.001s → 0 pu; 0.12s → 0 pu; 0.121s → 0.5 pu; 0.9s → 0.5 pu; 0.901s → 0.7 pu; 1s → 0.7 pu; 1.001s → 0.9 pu; 1200s → 0.9 pu; 1200s → 0.95 pu	verified
Australia (NER / AEMO) Australia	LVRT	ride-through	both	0.001s → 0 pu; 0.43s → 0 pu; 0.431s → 0.7 pu; 2s → 0.7 pu; 2.001s → 0.8 pu; 10s → 0.8 pu; 10.001s → 0.9 pu	verified
Austria (E-Control TOR Typ D) Austria	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.49s → 0.21 pu; 0.83s → 0.43 pu; 1.16s → 0.64 pu; 1.5s → 0.85 pu	verified
Belgium (Federal Grid Code) Belgium	LVRT	ride-through	transmission	0.001s → 0 pu; 0.2s → 0 pu; 0.53s → 0.21 pu; 0.85s → 0.43 pu; 1.18s → 0.64 pu; 1.5s → 0.85 pu	verified
Brazil (PRODIST / ONS) Brazil	LVRT	ride-through	transmission	0.001s → 0.2 pu; 0.5s → 0.2 pu; 0.501s → 0.281 pu; 0.625s → 0.444 pu; 0.75s → 0.606 pu; 0.875s → 0.769 pu; 1s → 0.85 pu; 5s → 0.85 pu; 5.001s → 0.9 pu	verified
California Rule 21 US	LVRT	ride-through	distribution	0.001s → 0 pu; 1s → 0 pu; 1.001s → 0.5 pu; 10s → 0.5 pu; 10.001s → 0.7 pu; 20s → 0.7 pu; 20.001s → 0.88 pu	verified
Canada (Alberta AESO) Canada	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.45 pu; 0.3s → 0.45 pu; 0.301s → 0.65 pu; 2s → 0.65 pu; 2.001s → 0.75 pu; 3s → 0.75 pu; 3.001s → 0.9 pu	verified
Chile (NTSyCS) Chile	LVRT	ride-through	unclear	0.001s → 0 pu; 0.14s → 0 pu; 0.141s → 0.067 pu; 0.283s → 0.2 pu; 0.427s → 0.333 pu; 0.57s → 0.467 pu; 0.713s → 0.6 pu; 0.857s → 0.733 pu; 1s → 0.8 pu	verified
Colombia (CREG 060/2019) Colombia	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.33s → 0.05 pu; 0.5s → 0.1 pu; 0.75s → 0.29 pu; 1s → 0.48 pu; 1.25s → 0.66 pu; 1.5s → 0.85 pu; 20s → 0.85 pu; 20.001s → 0.9 pu	verified
Denmark (TR 3.3.1) Denmark	LVRT	ride-through	both	0.001s → 0 pu; 0.15s → 0 pu; 0.3s → 0.094 pu; 0.45s → 0.189 pu; 0.6s → 0.283 pu; 0.75s → 0.378 pu; 0.9s → 0.472 pu; 1.05s → 0.567 pu; 1.2s → 0.661 pu; 1.35s → 0.756 pu; 1.5s → 0.85 pu	verified
ERCOT (NOG 2.9.1) US	LVRT	ride-through	transmission	0.001s → 0 pu; 0.32s → 0 pu; 0.321s → 0.096 pu; 0.4s → 0.141 pu; 0.48s → 0.186 pu; 0.56s → 0.231 pu; 0.594s → 0.25 pu; 1.2s → 0.25 pu; 1.201s → 0.5 pu; 3s → 0.5 pu; 3.001s → 0.7 pu; 6s → 0.7 pu; 6.001s → 0.9 pu	verified
ERCOT (NOG 2.9.1.2 legacy) US	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.35s → 0.1125 pu; 0.55s → 0.225 pu; 0.75s → 0.3375 pu; 0.95s → 0.45 pu; 1.15s → 0.5625 pu; 1.35s → 0.675 pu; 1.55s → 0.7875 pu; 1.75s → 0.9 pu	verified
Ecuador (ARCONEL-001/24 Código de Conexión) Ecuador	LVRT	ride-through	—	0.001s → 0 pu; 0.25s → 0 pu; 0.251s → 0.25 pu; 0.56s → 0.4 pu; 0.88s → 0.55 pu; 1.19s → 0.7 pu; 1.5s → 0.85 pu; 3600s → 0.9 pu	verified
Finland (Fingrid VJV2024) Finland	LVRT	ride-through	both	0.001s → 0 pu; 0.2s → 0 pu; 0.53s → 0.21 pu; 0.85s → 0.43 pu; 1.18s → 0.64 pu; 1.5s → 0.85 pu; 10s → 0.85 pu; 10.001s → 0.9 pu	verified
France (RTE) France	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.3s → 0.094 pu; 0.45s → 0.189 pu; 0.6s → 0.283 pu; 0.75s → 0.378 pu; 0.9s → 0.472 pu; 1.05s → 0.567 pu; 1.2s → 0.661 pu; 1.35s → 0.756 pu; 1.5s → 0.85 pu	verified
Greece (ADMIE/IPTO RfG) Greece	LVRT	ride-through	both	0.001s → 0 pu; 0.5s → 0 pu; 0.501s → 0.22 pu; 0.85s → 0.22 pu; 0.851s → 0.44 pu; 1.2s → 0.44 pu; 1.201s → 0.66 pu; 1.5s → 0.66 pu; 1.501s → 0.85 pu; 3s → 0.85 pu; 3600s → 0.9 pu	verified
IEEE 1547-2018 Cat III US	LVRT	ride-through	distribution	0.001s → 0 pu; 1s → 0 pu; 1.001s → 0.5 pu; 10s → 0.5 pu; 10.001s → 0.7 pu; 20s → 0.7 pu; 20.001s → 0.88 pu	verified
IEEE 2800-2022 US	LVRT	ride-through	transmission	0.001s → 0 pu; 0.32s → 0 pu; 0.321s → 0.25 pu; 1.2s → 0.25 pu; 1.201s → 0.5 pu; 3s → 0.5 pu; 3.001s → 0.7 pu; 6s → 0.7 pu; 6.001s → 0.9 pu	verified
India (CEA Connectivity Regs) India	LVRT	ride-through	transmission	0.001s → 0.15 pu; 0.3s → 0.15 pu; 0.301s → 0.85 pu; 3s → 0.85 pu; 3.001s → 0.9 pu	partial
Ireland (EirGrid) Ireland	LVRT	ride-through	both	0.001s → 0.15 pu; 0.625s → 0.15 pu; 0.626s → 0.209 pu; 1s → 0.209 pu; 1.001s → 0.347 pu; 1.5s → 0.347 pu; 1.501s → 0.505 pu; 2s → 0.505 pu; 2.001s → 0.663 pu; 2.5s → 0.663 pu; 2.501s → 0.821 pu; 3s → 0.821 pu; 3.001s → 0.9 pu	verified
Italy (TERNA) Italy	LVRT	ride-through	transmission	0.001s → 0 pu; 0.2s → 0 pu; 0.4s → 0.094 pu; 0.6s → 0.189 pu; 0.8s → 0.283 pu; 1s → 0.378 pu; 1.2s → 0.472 pu; 1.4s → 0.567 pu; 1.6s → 0.661 pu; 1.8s → 0.756 pu; 2s → 0.85 pu	verified
Kenya (KNTGC VRPP) Kenya	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.14 pu; 0.77s → 0.14 pu; 0.771s → 0.43 pu; 1.38s → 0.43 pu; 1.381s → 0.71 pu; 2s → 0.71 pu; 2.001s → 0.85 pu; 3s → 0.85 pu; 3.001s → 0.9 pu	verified
Malaysia (Grid Code Additional Code 2025) Malaysia	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.11 pu; 0.49s → 0.11 pu; 0.491s → 0.34 pu; 0.83s → 0.34 pu; 0.831s → 0.56 pu; 1.16s → 0.56 pu; 1.161s → 0.79 pu; 1.5s → 0.79 pu; 1.501s → 0.9 pu	verified
Mexico (Codigo de Red) Mexico	LVRT	ride-through	both	0.001s → 0 pu; 0.65s → 0 pu; 0.651s → 0.15 pu; 0.85s → 0.15 pu; 0.851s → 0.3 pu; 1.05s → 0.3 pu; 1.051s → 0.45 pu; 1.2s → 0.45 pu; 1.201s → 0.6 pu; 1.35s → 0.6 pu; 1.351s → 0.75 pu; 1.5s → 0.75 pu; 1.501s → 0.9 pu	verified
NERC PRC-024-4 (no-trip) US	LVRT	no-trip	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.45 pu; 0.3s → 0.45 pu; 0.301s → 0.65 pu; 2s → 0.65 pu; 2.001s → 0.75 pu; 3s → 0.75 pu; 3.001s → 0.9 pu; 4s → 0.9 pu	verified
NERC PRC-029-1 (IBR) US	LVRT	ride-through	transmission	0.001s → 0 pu; 0.32s → 0 pu; 0.321s → 0.25 pu; 1.2s → 0.25 pu; 1.201s → 0.5 pu; 3s → 0.5 pu; 3.001s → 0.7 pu; 6s → 0.7 pu; 6.001s → 0.9 pu	verified
NERC PRC-029-1 (Table 1: AC-connected wind IBR /…) US	LVRT	ride-through	transmission	0.001s → 0 pu; 0.16s → 0 pu; 0.161s → 0.25 pu; 1.2s → 0.25 pu; 1.201s → 0.5 pu; 2.5s → 0.5 pu; 2.501s → 0.7 pu; 3s → 0.7 pu; 3.001s → 0.9 pu	verified
Netherlands (TenneT) Netherlands	LVRT	ride-through	transmission	0.001s → 0 pu; 0.25s → 0 pu; 0.5s → 0.077 pu; 0.75s → 0.155 pu; 1s → 0.232 pu; 1.25s → 0.309 pu; 1.5s → 0.386 pu; 1.75s → 0.464 pu; 2s → 0.541 pu; 2.25s → 0.618 pu; 2.5s → 0.695 pu; 2.75s → 0.773 pu; 3s → 0.85 pu	verified
New Zealand North Island (EIPC cl 8.25A) New Zealand	LVRT	ride-through	transmission	0.001s → 0 pu; 0.14s → 0 pu; 0.141s → 0.14 pu; 0.26s → 0.14 pu; 0.261s → 0.21 pu; 0.38s → 0.21 pu; 0.381s → 0.28 pu; 0.5s → 0.28 pu; 0.501s → 0.57 pu; 0.65s → 0.57 pu; 0.651s → 0.59 pu; 0.87s → 0.59 pu; 0.871s → 0.645 pu; 1.09s → 0.645 pu; 1.091s → 0.7 pu; 1.3s → 0.7 pu; 1.301s → 0.76 pu; 3s → 0.76 pu; 3.001s → 0.9 pu	verified
New Zealand South Island (EIPC cl 8.25A) New Zealand	LVRT	ride-through	transmission	0.001s → 0 pu; 0.14s → 0 pu; 0.141s → 0.14 pu; 0.26s → 0.14 pu; 0.261s → 0.21 pu; 0.38s → 0.21 pu; 0.381s → 0.28 pu; 0.5s → 0.28 pu; 0.501s → 0.76 pu; 3s → 0.76 pu; 3.001s → 0.9 pu	verified
Nigeria (TCN Grid Code) Nigeria	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.14 pu; 0.77s → 0.14 pu; 0.771s → 0.43 pu; 1.38s → 0.43 pu; 1.381s → 0.71 pu; 2s → 0.71 pu; 2.001s → 0.85 pu	partial
Norway (Statnett NVF 2025) Norway	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.49s → 0.23 pu; 0.83s → 0.45 pu; 1.16s → 0.68 pu; 1.5s → 0.9 pu	verified
Panama (Código de Redes Fotovoltaico 2017) Panama	LVRT	ride-through	unclear	0.001s → 0 pu; 0.15s → 0 pu; 0.66s → 0.22 pu; 1.18s → 0.45 pu; 1.69s → 0.68 pu; 2.2s → 0.9 pu	partial
Peru (COES PR-20, Anexo 1 Cap. 4 Peru	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.4s → 0.1 pu; 0.65s → 0.2 pu; 1.43s → 0.42 pu; 2.22s → 0.63 pu; 3s → 0.85 pu; 62s → 0.88 pu; 121s → 0.92 pu; 180s → 0.95 pu	verified
Philippines PV (PGC 2016 Fig 4.4) Philippines	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.3 pu; 0.6s → 0.3 pu; 0.601s → 0.38 pu; 1.2s → 0.38 pu; 1.201s → 0.53 pu; 1.8s → 0.53 pu; 1.801s → 0.68 pu; 2.4s → 0.68 pu; 2.401s → 0.83 pu; 3s → 0.83 pu; 3.001s → 0.9 pu	verified
Philippines Wind (PGC 2016 Fig 4.2) Philippines	LVRT	ride-through	transmission	0.001s → 0.2 pu; 0.625s → 0.2 pu; 0.626s → 0.29 pu; 1.22s → 0.29 pu; 1.221s → 0.46 pu; 1.81s → 0.46 pu; 1.811s → 0.64 pu; 2.41s → 0.64 pu; 2.411s → 0.81 pu; 3s → 0.81 pu; 3.001s → 0.9 pu	verified
Poland (PSE Wymogi 2025) Poland	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.74s → 0.21 pu; 1.33s → 0.43 pu; 1.91s → 0.64 pu; 2.5s → 0.85 pu	verified
Quebec (Hydro-Quebec D-2022-088) Canada	LVRT	ride-through	transmission	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.044 pu; 0.3s → 0.044 pu; 0.301s → 0.103 pu; 0.5s → 0.103 pu; 0.501s → 0.176 pu; 0.75s → 0.176 pu; 0.751s → 0.25 pu; 1s → 0.25 pu; 1.001s → 0.75 pu; 2s → 0.75 pu; 2.001s → 0.85 pu; 30s → 0.85 pu; 30.001s → 0.9 pu	verified
Romania (Transelectrica/ANRE storage norm) Romania	LVRT	ride-through	transmission	0.001s → 0 pu; 0.95s → 0 pu; 0.951s → 0.21 pu; 1.65s → 0.21 pu; 1.651s → 0.43 pu; 2.35s → 0.43 pu; 2.351s → 0.64 pu; 3s → 0.64 pu; 3.001s → 0.85 pu; 3600s → 0.9 pu	verified
Saudi Arabia (SAGC) Saudi Arabia	LVRT	ride-through	transmission	0.001s → 0 pu; 0.3s → 0 pu; 0.301s → 0.13 pu; 0.63s → 0.13 pu; 0.631s → 0.4 pu; 0.97s → 0.4 pu; 0.971s → 0.67 pu; 1.3s → 0.67 pu; 1.301s → 0.9 pu	verified
South Africa (NRS 097 / RPP) South Africa	LVRT	ride-through	both	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.053 pu; 0.381s → 0.159 pu; 0.613s → 0.266 pu; 0.844s → 0.372 pu; 1.075s → 0.478 pu; 1.306s → 0.584 pu; 1.538s → 0.691 pu; 1.769s → 0.797 pu; 2s → 0.85 pu; 20s → 0.85 pu; 20.001s → 0.9 pu	verified
South Korea (KEPCO) South Korea	LVRT	ride-through	distribution	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.5 pu; 0.16s → 0.5 pu; 0.161s → 0.7 pu; 1.5s → 0.7 pu; 1.501s → 0.9 pu	verified
Spain (P.O. 12.3) Spain	LVRT	ride-through	unclear	0.001s → 0 pu; 0.15s → 0 pu; 0.3s → 0.094 pu; 0.45s → 0.189 pu; 0.6s → 0.283 pu; 0.75s → 0.378 pu; 0.9s → 0.472 pu; 1.05s → 0.567 pu; 1.2s → 0.661 pu; 1.35s → 0.756 pu; 1.5s → 0.85 pu	verified
Sri Lanka (CEB) Sri Lanka	LVRT	ride-through	transmission	0.001s → 0 pu; 0.14s → 0 pu; 0.141s → 0.13 pu; 0.49s → 0.13 pu; 0.491s → 0.4 pu; 0.85s → 0.4 pu; 0.851s → 0.67 pu; 1.2s → 0.67 pu; 1.201s → 0.8 pu; 2.5s → 0.8 pu; 2.501s → 0.85 pu; 180s → 0.85 pu; 180.001s → 0.9 pu	verified
Sweden (EIFS 2018:2) Sweden	LVRT	ride-through	transmission	0.001s → 0 pu; 0.2s → 0 pu; 0.65s → 0.21 pu; 1.1s → 0.43 pu; 1.55s → 0.64 pu; 2s → 0.85 pu; 10s → 0.85 pu; 10.001s → 0.9 pu	verified
Switzerland (Swissgrid CESS minimum requiremen…) Switzerland	LVRT	ride-through	transmission	0.001s → 0 pu; 0.2s → 0 pu; 0.53s → 0.21 pu; 0.85s → 0.43 pu; 1.18s → 0.64 pu; 1.5s → 0.85 pu	partial
Taiwan (TPC) Taiwan	LVRT	ride-through	both	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.045 pu; 0.435s → 0.135 pu; 0.72s → 0.225 pu; 1.005s → 0.315 pu; 1.29s → 0.405 pu; 1.575s → 0.495 pu; 1.86s → 0.585 pu; 2.145s → 0.675 pu; 2.43s → 0.765 pu; 2.715s → 0.855 pu; 3s → 0.9 pu	verified
Turkey (TEİAŞ Şebeke Yönetmeliği Ek-18 Turkey	LVRT	ride-through	transmission	0.001s → 0 pu; 0.49s → 0 pu; 0.491s → 0.22 pu; 0.83s → 0.22 pu; 0.831s → 0.45 pu; 1.16s → 0.45 pu; 1.161s → 0.67 pu; 1.5s → 0.67 pu; 1.501s → 0.9 pu	verified
UK G99 (Type A-C) UK	LVRT	ride-through	distribution	0.001s → 0.1 pu; 0.14s → 0.1 pu; 0.141s → 0.166 pu; 0.5s → 0.166 pu; 0.501s → 0.322 pu; 1s → 0.322 pu; 1.001s → 0.504 pu; 1.5s → 0.504 pu; 1.501s → 0.723 pu; 2.2s → 0.723 pu; 2.201s → 0.85 pu; 180s → 0.85 pu; 180.001s → 0.9 pu	verified
UK G99 (Type D) UK	LVRT	ride-through	transmission	0.001s → 0 pu; 0.14s → 0 pu; 0.141s → 0.074 pu; 0.5s → 0.074 pu; 0.501s → 0.252 pu; 1s → 0.252 pu; 1.001s → 0.458 pu; 1.5s → 0.458 pu; 1.501s → 0.706 pu; 2.2s → 0.706 pu; 2.201s → 0.85 pu; 180s → 0.85 pu; 180.001s → 0.9 pu	verified
Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) Vietnam	LVRT	ride-through	both	0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.3 pu; 0.6s → 0.3 pu; 0.601s → 0.38 pu; 1.2s → 0.38 pu; 1.201s → 0.53 pu; 1.8s → 0.53 pu; 1.801s → 0.68 pu; 2.4s → 0.68 pu; 2.401s → 0.83 pu; 3s → 0.83 pu; 3.001s → 0.9 pu	verified

Standards referenced on this page

The clause each plotted curve was read from is listed against that standard in the registry above. These are the primary documents behind the dataset:

IEEE Std 2800-2022 — Standard for Interconnection and Interoperability of Inverter-Based Resources (IBRs) Interconnecting with Associated Transmission Systems — IEEE, 2022 (plotted)
IEEE Std 1547-2018 — Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces — IEEE, 2018 (plotted)
NERC PRC-024-4 — Frequency and Voltage Protection Settings for Generating Resources. A protective-relay no-trip boundary, not a ride-through performance duty; plotted and tagged as such. — NERC (plotted)
NERC PRC-029-1 — Frequency and Voltage Ride-Through Requirements for Inverter-Based Resources. Approved by FERC Order No. 909 (Docket RM25-3-000, 24 July 2025); enforceable from 1 October 2026. — NERC (plotted)
ERCOT Nodal Operating Guides, Sections 2.6.2.1, 2.9.1.1 and 2.9.1.2 — ERCOT (plotted)
Engineering Recommendation G99 — Requirements for the connection of generation to distribution networks (Issue 2) — Energy Networks Association, Great Britain (plotted)
AESO ISO Rules Sections 503.5 and 503.6; IESO Market Rules Chapter 4 Appendix 4.2; Hydro-Québec Decision D-2022-088 — Canadian transmission requirements (plotted)
National Electricity Rules Schedule 5.2 and the AEMC Frequency Operating Standard — AEMO, Australia (plotted)

Researched but not plotted — see what this chart deliberately does not plot for the reason in each case: Commission Regulation (EU) 2016/631 (ENTSO-E RfG), VDE-AR-N 4110 and VDE-AR-N 4120 (Germany), GB/T 36547-2024 (China), and the Japanese utility interconnection requirements.