South Korea (KEPCO) — ride-through requirements

The LVRT, HVRT, FRT envelopes a grid-scale battery must meet under South Korea (KEPCO), digitized breakpoint by breakpoint and checked against the clause it came from.

By Sergey Syrvachev — Director of Product Engineering at HyperStrong

Applies to: distribution connections — DER at the distribution PCC, connection classes from LV to 22.9 kV.

Part of: the grid-code ride-through chart — compare this against 65 other standards in 44 countries.

What this is, and is not. A reading aid compiled from the clause cited below — not a compliance document. The primary text governs. Some values on this page are marked partial: the level is confirmed but at least one duration step could not be read directly from the source.

Breakpoints

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

EventDutyBreakpointsStatus
low-voltage ride-through (LVRT)ride-through0.001s → 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 puverified
high-voltage ride-through (HVRT)ride-through0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.1 puverified
frequency ride-through (FRT)ride-throughHigh: 0.1s → 61.5 Hz | Low: 0.1s → 57 Hz; 299s → 57 Hz; 299.001s → 57.5 Hzpartial

Where these values come from

  • LVRTKEPCO 분산형전원 배전계통 연계 기술기준 (업무표준 H0-배전-기준-0015, 개정 14, 2021-06-01), 제24조 (계통연계 유지 / Fault Ride-Through), <표 2.7> 비정상 전압에 대한 운전지속시간: V<50 → 0.15 s; 50<=V<70 → 0.16 s; 70<=V<90 → 1.5 s; 110<V<120 → 0.2 s; V>=120 → none. (Trip table <표 2.4> is separate.).
  • HVRTKEPCO 분산형전원 배전계통 연계 기술기준 (개정 14, 2021-06-01), <표 2.7>: 110 < V < 120 → 운전지속시간 0.2초; V >= 120 → '-' (no ride-through). Complementary trip table <표 2.4>: V>=120 → 분리시간 0.16 s.
  • FRTKEPCO 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.

Last checked against the source document on .

How South Korea compares

Each event this code defines, put side by side with every other code that defines it:

Other grid codes in Asia-Pacific