NERC PRC-029-1 (Table 1: AC-connected wind IBR) ride-through requirements
Low-voltage ride-through for the United States. 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 NERC PRC-029-1 (Table 1: AC-connected wind IBR)?
The plant must ride through for any voltage that stays on or above this envelope. The envelope holds 0 pu from t = 0 to 160 ms; then 0.25 pu from 160 ms to 1.2 s; then 0.5 pu from 1.2 s to 2.5 s; then 0.7 pu from 2.5 s to 3 s; then 0.9 pu from 3 s onward — the last band the envelope defines, with no stated end time.
Every breakpoint is stated in the clause cited below.
Applies to AC-connected wind IBR on the BES (per Attachment 1 note 1)
| From | To | Voltage | Between the points |
|---|---|---|---|
| 0 | 160 ms | 0 pu | Held flat |
| 160 ms | 1.2 s | 0.25 pu | Held flat |
| 1.2 s | 2.5 s | 0.5 pu | Held flat |
| 2.5 s | 3 s | 0.7 pu | Held flat |
| 3 s | no stated end | 0.9 pu | Held flat |
The clause this came from
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.
Who does NERC PRC-029-1 (Table 1: AC-connected wind IBR) bind, and since when?
AC-connected wind IBR on the BES (per Attachment 1 note 1). Enforceable from 1 Oct 2026 (FERC Order No. 909).
These figures are a reading aid, not legal advice. Grid codes are reissued: verify against the current edition before you design to them.
Digitised operating parameters beyond ride-through — droop, reactive capability, operating ranges — are published for 36 of the 66 codes in this atlas, not yet for NERC PRC-029-1 (Table 1: AC-connected wind IBR). That is a gap on this site, not a statement that NERC PRC-029-1 (Table 1: AC-connected wind IBR) sets none — the atlas hub marks the codes that carry 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 NERC PRC-029-1 (Table 1: AC-connected wind IBR)
- Does NERC PRC-029-1 (Table 1: AC-connected wind IBR) require ride-through, or only that the plant does not trip?
- Ride-through. Every envelope on this page is a performance duty the plant must meet, not a protection-setting no-trip boundary — they are different obligations. That is what these curves are; they are not everything NERC PRC-029-1 (Table 1: AC-connected wind IBR) contains. The requirement sentence under each chart says which side of the curve is the compliant one.
- Are the numbers on this page taken from NERC PRC-029-1 (Table 1: AC-connected wind IBR) 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 NERC PRC-029-1 (Table 1: AC-connected wind IBR)?
- NERC PRC-029-1 (Table 1: AC-connected wind IBR) is charted here with 1 envelope — low-voltage ride-through (LVRT). No high-voltage or frequency envelope is charted here — check NERC PRC-029-1 (Table 1: AC-connected wind IBR) itself before concluding it sets none.
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.
Also for the United States: NERC PRC-024-4 (ERCOT), NERC PRC-024-4 (no-trip), NERC PRC-024-4 (Western), NERC PRC-029-1 (IBR), Transient overvoltage (IEEE 2800 TOV), California Rule 21, and 5 more