EIFS 2018-2 Nätanslutning av generatorer

EIFS 2018:2 — Energimarknadsinspektionens föreskrifter om fastställande av generellt tillämpliga krav för nätanslutning av generatorer. Sweden’s national implementing regulation for RFG (EU 2016/631). Specifies the nationally determined parameter values that RFG leaves open for member states and NRAs to set for the Nordic synchronous area.

Full title: EIFS 2018:2 — Ei:s föreskrifter om fastställande av generellt tillämpliga krav för nätanslutning av generatorer

Decision date: 8 November 2018

In force: 27 April 2019

Legal basis: Förordning (1994:1806) om systemansvaret för el, §§ 16b and 16d

EU parent: Commission Regulation (EU) 2016/631

ISSN: 2000-592X

Summary

EIFS 2018:2 fills in the nationally variable parameters that RFG leaves to member states and NRAs — primarily frequency operating ranges, ramp rates by technology type, fault ride-through profiles, and FSM (Frequency Sensitive Mode) settings for the Nordic synchronous area. The regulation has six chapters: introductory provisions (1 kap.), scope (2 kap.), general requirements by type A–D (3 kap.), and specific requirements for synchronous modules (4 kap.), power park modules (5 kap.) and offshore power park modules (6 kap.).

Key content

Chapter 3 — General requirements (all types)

Frequency operating ranges (§§ 1–2): All types A–D must remain connected within:

• 47.5–48.5 Hz: ≥ 30 minutes
• 48.5–49.0 Hz: ≥ 30 minutes
• 49.0–51.0 Hz: unlimited
• 51.0–51.5 Hz: ≥ 30 minutes

Rate of change of frequency (RoCoF) tolerance: ≥ 2.0 Hz/s, measured over 500 ms.

LFSM-O (overfrequency response, §§ 3–6): All types must reduce active power output when frequency exceeds 50.5 Hz. Droop setting (statikfaktor): primary setting 8 %. Automatic disconnection is prohibited as an alternative to power reduction.

LFSM-U (underfrequency response, §§ 20–22): Types C and D must also increase active power output when frequency drops below 49.5 Hz.

Reconnection rules (§§ 8–9): Types A–C may reconnect automatically when frequency is within 47.5–50.1 Hz, provided the frequency has been within this band for ≥ 3 consecutive minutes. Reconnection ramp (§9): no ramp limit below 49.9 Hz; max 10 % of nominal output per minute at 49.9–50.1 Hz; no increase above 50.1 Hz.

Chapter 3 — Ramp rates by technology (§§ 31–32)

Ramp rates for Type C and D generators “vid effektreglering” (§31; the §19 setpoint-change requirement is separate):

The 100 %/min ramp rate for kraftparksmoduler (wind, solar, batteries) is the highest in the table, 2.5 times the next-highest (hydro, 40 %/min), though over a narrower control range (85 % of nominal power, within 15–100 %). The regulation states the requirement only; the wiki reading is that this reflects power electronics not being limited by mechanical or thermal constraints, which underpins the flexibility value of battery storage and controllable wind/solar.

Step-change response (§32, within 49–51 Hz): kraftparksmoduler 30 % within 15 seconds over the 50–100 % power range.

Chapter 3 — FSM (Frequency Sensitive Mode, §§ 23–29)

FSM (frekvenskänslighetsläge) applies to Type C and D only:

• Capability is mandatory for Type C/D generators.
• Activation is TSO-controlled: “FSM ska endast vara aktiverat om den systemansvariga myndigheten beordrar det” (§23). Svenska kraftnät (Svk) decides when FSM is engaged; it is not a continuous operating requirement.
• Droop range: 2–12 % statikfaktor (§24).
• Frequency insensitivity: ≤ 10 mHz (§25).
• Deadband: ±100 mHz by default (§26).
• Active power range for FSM: 5–10 % of max continuous power (§27).
• Duration of full response: ≥ 15 minutes (§28).
• Initial response delay for modules “utan tröghet” (without inertia; typically power-electronics-interfaced modules): < 2 seconds (§29).

The TSO-activation condition means that Type C/D generators (including kraftparksmoduler) must have FSM capability, but FSM is only to be active when Svk orders it (§23). How this relates to FCR participation (Balancing Markets) is not addressed in EIFS 2018:2.

Chapter 3 — Fault ride-through (§§ 11–16, 35–40)

Fault ride-through (feltålighet) parameters define how generators must behave during and after voltage dips caused by grid faults. Different profiles for synchronous generators vs. kraftparksmoduler:

Kraftparksmodul Type B/C fault ride-through: Minimum voltage during fault: 0.15 p.u. (more lenient than synchronous generators which must hold 0.25 p.u.). Recovery to 0.85 p.u. within 2 seconds; full recovery to 0.90 p.u. assumed within 10 seconds.

Kraftparksmodul Type D fault ride-through: Even more demanding — must ride through 0.0 p.u. (complete voltage collapse) for up to 200 ms, recovering to 0.85 p.u. within 2 seconds.

Chapter 4 — Synchronous generator requirements

Voltage regulation, magnetisation, and power system stabiliser (PSS) requirements for synchronous machines. Types B–D require automatic voltage regulators. Types C–D must have reactive power capability at the connection point of at least 1/3 of instantaneous active power for generation (within 90–102 % voltage) and 1/6 for consumption (within 95–105 % voltage), unless the network owner notifies another requirement (§§8–9). Type D generators > 75 MVA require PSS (kraftsystemstabilisator) for damping power oscillations at 0.25–1 Hz.

Chapter 5 — Power park module requirements

Active power recovery for kraftparksmoduler after fault: within 2 seconds of voltage recovering above 90 %, active power must return to within 5 % of pre-fault level (§1). Types C/D require reactive power generation of at least 1/3 of instantaneous active power (90–102 % voltage) and consumption of at least 1/3 (95–105 % voltage) — a stricter consumption requirement than the 1/6 for synchronous modules — unless the network owner notifies another requirement (§§2–3). Types C/D must also have a PSS function active in the 0.25–1 Hz band (§7).

Chapter 6 — Offshore requirements

Offshore kraftparksmoduler (types A–D) connected at 300–400 kV must operate for ≥ 60 minutes in the 105–110 % voltage range (§1), and must have reactive power capability of at least 1/3 of instantaneous active power for generation (90–102 % voltage) and for consumption (95–105 % voltage), unless the network owner notifies another requirement (§§2–3).

Pending revision (paused, July 2026)

Ei began revising EIFS 2018:2 in 2025 and issued a remissförslag in February 2026 (coordination requirements between system operators on site-specific requirements, converting some national generally-applicable requirements into site-specific ones, and clearer cross-references to RfG articles). With the European Commission now consulting on a formal draft revised RfG covering much of the same ground, Ei has decided not to proceed with these substantive changes at this stage, to avoid double regulatory change ahead of the new RfG’s adoption. Ei will instead review EIFS 2018:2 for consequential updates (e.g. references to updated bemyndiganden, possibly a dispensation rule) once the EU-level revision is clearer. See Source - EU Commission Draft Revised RfG and Annexes (2026) and Generator Connection Requirements › NC RfG 2.0 — the Commission’s draft revised RfG (July 2026).

Relevance to wiki topics