Denmark (TR 3.3.1) ride-through requirements
Low-voltage ride-through, Frequency ride-through for Denmark. Every breakpoint below is read from the code itself, and carries the clause it came from — so you can check it, not just cite it.
What is the low-voltage ride-through envelope for Denmark (TR 3.3.1)?
The plant must ride through for any voltage that stays on or above this envelope. The envelope holds 0 pu from t = 0 to 150 ms; then ramps linearly from 0 pu at 150 ms to 0.85 pu at 1.5 s; then 0.85 pu from 1.5 s onward — the last band the envelope defines, with no stated end time.
The clause states this boundary as a line; intermediate points are interpolated between its stated vertices.
Applies to Battery plants; cited tables are the transmission-connected rows
| From | To | Voltage | Between the points |
|---|---|---|---|
| 0 | 150 ms | 0 pu | Held flat |
| 150 ms | 1.5 s | 0 → 0.85 pu | Ramps linearly |
| 1.5 s | no stated end | 0.85 pu | Held flat |
The clause this came from
Energinet Technical Regulation 3.3.1 – Revision 6 (14 Feb 2025, effective 1 May 2025), Part 16, section 128(1) and Table 45 (DK1); section 129(1) and Table 46 (DK2); cf. sections 90/114 Tables 39/40/43/44 for distribution-connected categories. The code defines a linear recovery ramp; the vertices are read from the clause and the chart draws the segment between them.
What is the frequency ride-through envelope for Denmark (TR 3.3.1)?
The plant must ride through between the upper and lower bands. The upper (over-frequency) band holds 51.5 Hz from t = 0 to 30 min; then 51 Hz from 30 min onward — the last band the envelope defines, with no stated end time. The lower (under-frequency) band holds 47.5 Hz from t = 0 to 30 min; then 48.5 Hz from 30 min to 60 min; then 49 Hz from 60 min onward — the last band the envelope defines, with no stated end time.
The last band has no stated end time. The clause below states a continuous region — highlighted; check which band it covers, because it is not always the last one.
Applies to Battery plants; cited tables are the transmission-connected rows
Upper limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 30 min | 51.5 Hz | Held flat |
| 30 min | no stated end | 51 Hz | Held flat |
Lower limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 30 min | 47.5 Hz | Held flat |
| 30 min | 60 min | 48.5 Hz | Held flat |
| 60 min | no stated end | 49 Hz | Held flat |
The clause this came from
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.
How long must the plant keep operating outside nominal voltage under Denmark (TR 3.3.1)?
The ride-through envelopes above answer how deep a disturbance the plant must survive. These bands answer the other question Denmark (TR 3.3.1) settles: how long it must keep operating at a voltage that is off nominal but steady.
A blue band ending in an arrow runs on, because the code states no end for it; a copper bar stops at the time the code prints, and only that right-hand end is data — every bar starts at the left edge of the axis.
Two figures cover three tables, in the order shown: DK2's 110-300 kV and above-300 kV tables, which state identical bands, then DK1 at 110-300 kV. The DK1 above-300 kV table is the one omission — in the English translation it states 0.9–1.10 pu unlimited alongside 1.05–1.10 pu for 60 minutes, two bands that overlap. The register reads that as an inconsistency in the translation rather than in the requirement, and the Danish text is the controlling version; the translated row is in the table below.
Steady-state voltage operating bands — DK2, 110-300 kV and above 300 kV
Voltage range [pu] at the point of connection, referred to Uc, the normal operating voltage determined by the relevant system operator
Steady-state voltage operating bands — DK1 110-300 kV
Voltage range [pu] at the point of connection, referred to Uc, the normal operating voltage in the point of connection determined by the relevant system operator
Operating requirements beyond the envelopes.
The figures above are what Denmark (TR 3.3.1) demands during a disturbance and while it sits off nominal. The rows below are the same regime’s operating and fault-response requirements — reactive capability, frequency response, continuous operating range, ramp rate, RoCoF withstand and fault-current injection — each researched from the document its own row cites, separately from the plotted corpus. Every row carries its clause and a verbatim quote, so you can check it the same way, including the continuous-operating-range row the staircases above are drawn from.
| Requirement | What the code states | Clause |
|---|---|---|
| P-Q capability rectangle (Q/Pn = ±0.33) Reactive capability | Rectangle: Q/Pn = -0.33 to +0.33 (PF = 0.95) available over the full active-power range P/Pn = -1.0 (consumption) to +1.0 (production), supply and absorb, at the point of connection Binds non-synchronous energy storage facilities connected to the transmission system (Part 16, via Section 125 compliance list); numeric envelope read from Figure 39 axis annotations 'Q/Pn = -0.33 PF = 0.95' and 'Q/Pn = 0.33 PF = 0.95' with the hatched rectangle spanning P/Pn -1.0 to +1.0. | Section 126(1), Figure 39 |
The clause this row citesSection 126(1), Figure 39 — “ 126.-(1) Energy storage facilities must be capable of supplying and absorbing reactive power in the point of connection within the operating range specified in Figure 39. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| Voltage-dependent U-Q/Pn envelope at maximum power Reactive capability | At maximum active power exchange: Q/Pn = ±0.33 within a voltage-dependent envelope — DK1 110-300 kV: UPOC 0.968-1.118 pu; DK2 110-300 kV and all 300-400 kV connections: 0.90-1.05 pu. The full ±0.33 holds over the mid-band only, tapering toward the envelope corners per Figures 40-42 Binds non-synchronous energy storage facilities connected to the transmission system (Part 16); shape is a sloped-corner polygon (Q availability narrows at the voltage extremes), values read from Figures 40 (DK1 110-300 kV), 41 (DK2 110-300 kV) and 42 (300-400 kV), all annotated 'Q/Pn = -0.33' / 'Q/Pn = 0.33'. | Section 127(1), Figures 40-42 |
The clause this row citesSection 127(1), Figures 40-42 — “ 127.-(1) At maximum active power exchange, energy storage facilities must be able to supply and absorb reactive power in the point of connection within the operating range, as shown for connections at 110-300 kV in Figure 40 for DK1 and Figure 41 for DK2, and for connections at 300-400 kV in Figure 42. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| LFSM-O droop, threshold and response times Frequency response | Droop default 5% (DK1) / 4% (DK2), settable 2-12% in 1-percentage-point steps; threshold set to 50.20 Hz (DK1) / 50.50 Hz (DK2), settable 50.20-50.50 Hz at 10 mHz resolution; response commenced <= 2 s after frequency change detected; fully supplied within 30 s Binds all energy storage facilities 0.8 kW or larger (Part 2, cascades to types B/C/D and transmission-connected); distribution-connected facilities must wait 500 ms before starting downward adjustment (island-detection); if power flow reverses the droop must be followed in the opposite flow. The 500 ms island-detection wait and the reverse-flow droop rule are stated in the elided sub-items of the same clause, cited but not quoted. | Section 23(1)-(2) |
The clause this row citesSection 23(1)-(2) — “ (2) The LFSM-O function under subsection (1) above must: a) be able to be set to any value in the 50.20-50.50 Hz range with a maximum resolution of 10 mHz b) be set to 50.20 Hz for DK1 and 50.50 Hz for DK2, unless otherwise stipulated by Energinet c) be set with a droop of 5% for DK1 and 4% for DK2 d) have a resolution for the droop of 1 percentage point, and it must be possible to set the droop in the 2-12% range ... h) be commenced no later than 2 seconds after the frequency change is detected ... i) be fully supplied within 30 seconds. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| LFSM-U droop, threshold and response times Frequency response | Droop default 5% (DK1) / 4% (DK2), settable 2-12% in 1-percentage-point steps; threshold set to 49.80 Hz (DK1) / 49.50 Hz (DK2), settable 49.50-49.80 Hz at 10 mHz resolution; response commenced <= 2 s; fully supplied within 30 s Section 52 sits in Part 4, so it binds type C (3-25 MW) and, via the compliance cascades in Sections 63 and 125, type D (>= 25 MW) and transmission-connected facilities; facilities that cannot reverse from consumption to production mode must disconnect at 49.00 Hz (DK1) / 48.80 Hz (DK2) per Table 22. The 2-12% droop-setting range and its 1-percentage-point resolution are stated in the elided sub-item (d) of the same clause, cited but not quoted. | Section 52(1)-(2) |
The clause this row citesSection 52(1)-(2) — “ (2) The LFSM-U function under subsection (1) above must: a) be able to be set to any value in the 49.50-49.80 Hz range with a maximum resolution of 10 mHz b) be set to 49.80 Hz for DK1 and 49.50 Hz for DK2, unless otherwise specifically stipulated by Energinet c) be set with a droop of 5% for DK1 and 4% for DK2 ... h) be commenced no later than 2 seconds after the frequency change is detected ... i) be fully supplied within 30 seconds. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| FSM band, active-power range and droop range Frequency response | FSM band: DK1 49.80-50.20 Hz, DK2 49.50-50.50 Hz (Table 23); active-power response range settable from 1.5% to 10% as a minimum; droop settable 2-12% in 1-percentage-point steps; sensitivity 10 mHz or less Binds type C (3-25 MW) and above (Part 4, cascading to type D and transmission-connected via Sections 63 and 125); no explicit FSM deadband value or full-activation time is stated in Section 53 itself (compliance testing in Part 18 verifies dead band and activation against the FSM control-function provisions). | Section 53(1)-(2), Table 23 |
The clause this row citesSection 53(1)-(2), Table 23 — “ 53.-(1) In the event of frequency deviations in the electricity supply system, energy storage facilities must have control functions that can provide frequency control to stabilise the frequency (Frequency Sensitivity Mode, FSM), depending on the synchronous area, as specified in Table 23 ... (2) The FSM control function under subsection (1) above must: a) be able to set the range for active power from 1.5% to 10% as a minimum b) have a resolution for the droop of 1 percentage point, and it must be possible to set the droop in the 2-12% range c) have a sensitivity of 10 mHz or less. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| Continuous frequency operating range (transmission-connected) Continuous operating range | Connected at 110-300 kV in DK1 (Table 30): 49.0-51.0 Hz unlimited; 47.5-48.5 Hz for 30 minutes; 48.5-49.0 Hz for 30 minutes; 51.0-51.5 Hz for 30 minutes. If frequency is below 49.00 Hz for more than 60 minutes, the facility is not required to stay connected beyond those 60 minutes. Variants: at above 300 kV in DK1 (Table 32) and at both 110-300 kV and above 300 kV in DK2 (Tables 34/36) the sub-49 Hz bands are 47.5-48.0 Hz / 30 min and 48.0-49.0 Hz / 30 min, with 49.0-51.0 Hz unlimited and 51.0-51.5 Hz / 30 min the same. Binds energy storage facilities (BESS explicitly - this is a storage-native regulation) connected to the transmission system: Part 6 (sections 67-71). Section 67(1)(a) exempts transmission-connected facilities from the distribution-level normal frequency and voltage operating ranges in sections 5 and 31, replacing them with sections 68-71 per connection level (110-300 kV / above 300 kV) and synchronous area (DK1 / DK2). The times are the durations for which the facility 'must be able to continuously operate' in each band. Separate protection trip settings (f< 47.5 Hz, f> 51.5 Hz, 200 ms) are trip thresholds, not operating bands, and are not restated here. | Section 68(1) and Table 30 (Part 6 - Energy storage facilities connected to the transmission system) + Table 30 'Normal frequency operating range when connected at 110-300 kV in DK1' |
The clauses this row citesSection 68(1) and Table 30 (Part 6 - Energy storage facilities connected to the transmission system) — “ Energy storage facilities connected at 110-300 kV in DK1 must be able to continuously operate at voltages and frequencies specified in Table 30, Table 31 and Figure 10. If frequency is below 49.00 Hz for more than 60 minutes, the facility is not required to stay connected for longer than these 60 minutes. ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) Table 30 'Normal frequency operating range when connected at 110-300 kV in DK1' — “ [Table 30 transcription] Frequency range [Hz] / Time [minutes]: 47.5-48.5 - 30; 48.5-49.0 - 30; 49.0-51.0 - Unlimited; 51.0-51.5 - 30. ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) | ||
| Continuous voltage operating range (transmission-connected) Continuous operating range | Connected at 110-300 kV in DK1 (Table 31): 0.9-1.118 pu unlimited; 0.85-0.9 pu for 60 minutes; 1.118-1.15 pu for 60 minutes. DK2, both 110-300 kV and above 300 kV (Tables 35/37): 0.9-1.05 pu unlimited; 1.05-1.10 pu for 60 minutes. Above 300 kV in DK1 (Table 33, as printed): 0.85-0.9 pu 60 min; 0.9-1.10 pu Unlimited; 1.05-1.10 pu 60 min. Binds energy storage facilities connected to the transmission system (Part 6, sections 68-71); ranges are in pu at the point of connection (for connections above 1 kV the regulation's references are to Uc, defined in the regulation's definitions as the normal operating voltage in the point of connection determined by the relevant system operator). Distribution-connected facilities instead use the ranges in sections 5 and 31 (section 67(1)(a) exemption). The times are the durations for which the facility 'must be able to continuously operate' in each band. Editorial caution: Table 33 as printed contains overlapping rows (0.9–1.10 pu unlimited and 1.05–1.10 pu for 60 min); the DK2 tables use a non-overlapping split, and the Danish text controls. | Section 68(1) and Table 31 (Part 6); variants in sections 69-71, Tables 33/35/37 + Table 35 'Normal voltage operating range when connected at 110-300 kV in DK2' |
The clauses this row citesSection 68(1) and Table 31 (Part 6); variants in sections 69-71, Tables 33/35/37 — “ [Table 31 transcription] Voltage range [pu] / Time [minutes]: 0.85-0.9 - 60; 0.9-1.118 - Unlimited; 1.118-1.15 - 60. (Caption: 'Table 31 Normal voltage operating range when connected at 110-300 kV in DK1.') ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) Table 35 'Normal voltage operating range when connected at 110-300 kV in DK2' — “ [Table 35 transcription] Voltage range [pu] / Time [minutes]: 0.9-1.05 - Unlimited; 1.05-1.10 - 60. ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) | ||
| Ramp rate constraint function (settable range) Ramp rate | Settable 1-20 %/min (of Pn), subject to a maximum of 1 MW/s, for both upward and downward active-power adjustment; the maximum gradient applies unless the relevant system operator stipulates a lower one; does not apply to ancillary-service delivery or activation of required technical properties Section 32 sits in Part 3, binding type B (125 kW-3 MW) and, via the compliance cascades in Sections 46, 63 and 125, types C, D and transmission-connected facilities; Table 15 states Minimum 1 %/min, Maximum 20 %/min, Maximum 1 MW/s. | Section 32(1)-(3), Table 15 |
The clause this row citesSection 32(1)-(3), Table 15 — “ 32.-(1) The energy storage facility must be equipped with a ramp rate constraint function that can be used for both upward and downward adjustment of active power, and can be set to any value within the ramp rate ranges specified in Table 15. ... (2) The energy storage facility must normally apply the maximum gradient under subsection (1) unless the relevant system operator stipulates a lower gradient. (3) The ramp rate requirement under subsection (1) above does not apply to the supply of ancillary services or the activation of a required technical property in the energy storage facility. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| Active-power gradient at automatic connection/reclosure Ramp rate | 20% of Pn per minute, subject to a maximum of 1 MW per second, during automatic closing and reclosing; does not apply to ancillary services or LFSM-U/LFSM-O activation Part 2 requirement for facilities 0.8 kW or larger; type B and larger are expressly excepted from Section 8 (Sections 30(1)(a), 46, 63) and use the Section 32 ramp rate constraint function instead, so this gradient effectively binds type A (< 125 kW). | Section 8(1)-(3) |
The clause this row citesSection 8(1)-(3) — “ 8.-(1) During automatic closing and reclosing, energy storage facilities 0.8 kW or larger in size must set the active power gradient to 20% of Pn per min., subject to a maximum of 1 MW per second. ... (3) The ramp rate requirement under subsection (1) above does not apply to the supply of ancillary services or the activation of a required technical property in the energy storage facility, including LFSM-U and LFSM-O. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| RoCoF withstand RoCoF withstand | ±2 Hz/s at the point of connection, without disconnecting or shutting down; per Figure 3, RoCoF is calculated from two 200 ms frequency-averaging windows offset by 20 ms (df/dt = (average value 2 - average value 1)/0.020) Binds all energy storage facilities 0.8 kW or larger (Part 2, cascades to all types including transmission-connected); Section 25 additionally allows df/dt protection at ±2.5 Hz/s / 80 ms, with the Section 11 RoCoF withstand taking precedence over that protection setting. | Section 11(1), Figure 3 |
The clause this row citesSection 11(1), Figure 3 — “ 11.-(1) Energy storage facilities 0.8 kW or larger in size must be able to withstand transient frequency gradients (RoCoF), calculated according to the method in Figure 3, of up to ±2 Hz/s in the point of connection, without disconnecting from the POC and without shutting down. ” (Technical Regulation 3.3.1 - Revision 6: Requirements for Energy Storage Facilities (English translation), accessed 2026-07-28) | ||
| Fast Fault Current (FFC) - positive-sequence reactive current during faults Fault-current injection | A control function for the positive sequence of the reactive current during a fault sequence (FFC) that commences within 100 ms after the voltage dip and follows the Figure 45 (DK1) / Figure 46 (DK2) characteristic, starting from 0.9 pu down to 0.5 pu voltage, with a tolerance of ±20% of In. The figures plot IQ/In against U: the characteristic rises linearly to IQ/In = 1.0 pu at U = 0.5 pu and stays at 1.0 pu for voltages below 0.5 pu, with the ±0.2 pu tolerance band drawn around it (figure reading). Part 16 - Non-synchronous energy storage facilities connected to the transmission system - so it binds inverter-based (non-synchronous) BESS explicitly; section 133 covers DK1, section 134 (whose chapeau says 'connected to the transmission system') covers DK2. Requirement is expressed for the positive sequence only; no numeric negative-sequence injection requirement is stated in these sections. Distribution side: section 115 (Part 13, non-synchronous type B facilities) imposes the analogous FFC via Figure 33, commencing within 100 ms and running from 0.9 Un to 0.5 Un (up to 1 kV) / 0.9 Uc to 0.5 Uc (above 1 kV) with a tolerance of ±20% of In. Editorial caution: DK1 Figure 45 draws the fast-fault-current knee at 0.85 pu where §133(2)(b) states 0.9 pu; the Danish text controls. | Sections 133(1)-(2) and 134(1)-(2), Figures 45-46 (Part 16 - Non-synchronous energy storage facilities connected to the transmission system) + Section 134(1)-(2), Figure 46 (FFC for DK2) |
The clauses this row citesSections 133(1)-(2) and 134(1)-(2), Figures 45-46 (Part 16 - Non-synchronous energy storage facilities connected to the transmission system) — “ Energy storage facilities must have a control function capable of controlling the positive sequence of the reactive current during a fault sequence (Fast Fault Current, FFC), as specified in Figure 45. [...] (2) Control in line with subsection (1) above must: a) commence within 100 ms after the voltage dip, and b) follow the characteristic in Figure 45, starting from 0.9 pu to 0.5 pu with a tolerance of ±20% of In. ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) Section 134(1)-(2), Figure 46 (FFC for DK2) — “ Energy storage facilities connected to the transmission system must have a control function capable of controlling the positive sequence of the reactive current during a fault sequence (Fast Fault Current, FFC), as specified in Figure 46. [...] (2) Control in line with subsection (1) above must: a) commence within 100 ms after the voltage dip, and b) follow the characteristic in Figure 46, starting from 0.9 pu to 0.5 pu with a tolerance of ±20% of In. ” (Technical Regulation 3.3.1 - Requirements for Energy Storage Facilities, Revision 6 (English translation), accessed 2026-08-08) | ||
Who does Denmark (TR 3.3.1) bind, and since when?
Battery plants; cited tables are the transmission-connected rows. The LVRT clause quoted above carries the date of effect — "effective 1 May 2025".
These figures are a reading aid, not legal advice. Grid codes are reissued: verify against the current edition before you design to them.
Curve data last checked against the code on — 66 standards, 130 envelopes, published by bess.engineer under CC BY 4.0.
Questions this page answers about Denmark (TR 3.3.1)
- Does Denmark (TR 3.3.1) require ride-through, or only that the plant does not trip?
- Ride-through, for the envelopes on this page — that is what each of them is. It is not everything Denmark (TR 3.3.1) contains: the clauses quoted under the charts also address when the plant may or must trip. The requirement sentence under each chart says which side of the curve is the compliant one.
- Are the numbers on this page taken from Denmark (TR 3.3.1) itself?
- Yes. Every breakpoint is read from the code, and each envelope carries the clause it came from, quoted in full under its chart — so you can check the figure against the standard rather than cite it from this page.
- Which events are charted for Denmark (TR 3.3.1)?
- Denmark (TR 3.3.1) is charted here with 2 envelopes — low-voltage ride-through, frequency ride-through (LVRT, FRT). No high-voltage envelope is charted here — check Denmark (TR 3.3.1) itself before concluding it sets none. Its steady-state voltage-band figures add 2 more, drawn from the code's continuous-operating-range table rather than from a ride-through curve.
Ride-through, in context.
An envelope is a compliance boundary; understanding why it exists is a different question. The ride-through and grid-forming entries cover the engineering, and the Engineering Foundations course builds it from the physics up.
Elsewhere in Europe: Romania (Transelectrica/ANRE storage norm), Spain (P.O. 12.3), Sweden (EIFS 2018:2), Switzerland (Swissgrid CESS minimum), Switzerland (Swissgrid TC-CH 2019), Turkey (TEİAŞ Şebeke Yönetmeliği Ek-18), and 13 more