地域間連系線 · OCCTO 5-min flow actuals → 30-min slots · operating capacity, margin, ATC · congestion vs JEPX area price splits
Grid & Interconnectors
Congested tie-line hours / day
47.0h
2,442 h over 52 days · 9 market links · 1 base-flow link excluded
Most congested link
53%of slots
Soma-Futaba (Tohoku–Tokyo)
Area splits explained by congestion
40%
split slots (adjacent pairs) with the link at ≥95%
Slots with ≥1 congested link
91%
share of all half-hours in window
Mean utilisation
66%
|flow| ÷ usable capacity, all links
Congested links · 2026-09-25
7/ 9
links with ≥1 congested slot on the latest day
Congestion outlook — forward ATC
OCCTO capacity offered to the spot auction (D-2) and the post-spot plan (D-1) vs 30-day actual usable capacity
Loading market data…
Tie-line map
Click a link · 2026-06-28 → 2026-09-25 · congested = ≥ 95% of usable capacity
Line width = mean |flow| · arrow = dominant direction · dashed ring = loop-area fence (net boundary flow) · label & colour = congested share of slots:≥25%10–25%3–10%<3%base flowSpread matrix →
Daily congested hours by link
Sum of half-hours at ≥ 95% utilisation, stacked per tie-line
Tie-lines · utilisation, congestion & price-split linkage
One row per OCCTO interconnector · click a row for the slot profile, daily series and heatmap
| Link | Forward | Usable fwd / rev | Mean flow | Fwd % | Util. | P90 util. | Congested | h / day | Split % | Split | cong. | Explained | |Δ| cong / free | Yesterday |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Hokkaido–Honshu HVDC 北海道・本州間電力連系設備 · HVDC | HKD → THK | 407 / 37 | +242 | 93 | 67% | 99% | 25.5% | 6.1 (291f/28r) | 45 | 76% vs 34% | 43% | ¥5.12 / ¥1.91 | 9.0 h |
Soma-Futaba (Tohoku–Tokyo) 相馬双葉幹線 · AC 500kV | THK → TKO | 4,445 / 2,165 | +4,073 | 100 | 91% | 101% | 53.0% | 12.7 (662f/0r) | 49 | 72% vs 24% | 77% | ¥6.90 / ¥1.75 | 15.0 h |
Frequency converters (50/60 Hz) 周波数変換設備 · FC | TKO → CBU | 907 / 1,086 | -110 | 45 | 69% | 102% | 32.1% | 7.7 (210f/192r) | 39 | 55% vs 32% | 45% | ¥2.37 / ¥1.02 | 6.0 h |
Chubu fence (Chubu ↔ Hokuriku+Kansai) 中部フェンス · AC loop fence | CBU → Hokuriku + Kansai | 1,784 / 2,752 | -2,294 | 1 | 84% | 100% | 34.6% | 8.3 (0f/432r) | 70 | 85% vs 62% | 42% | ¥6.31 / ¥3.41 | 15.0 h |
Hokuriku fence (Chubu+Kansai ↔ Hokuriku) 北陸フェンス · AC loop fence | HRK → Chubu + Kansai | 2,388 / 3,182 | -418 | 10 | 15% | 28% | 0.0% | 0.0 (0f/0r) | 6 | — vs 6% | 0% | ¥— / ¥0.23 | 0.0 h |
Kansai fence (Chubu+Hokuriku ↔ Kansai) 関西フェンス · AC loop fence | KNS → Chubu + Hokuriku | 1,853 / 2,746 | -1,883 | 2 | 69% | 91% | 5.6% | 1.4 (0f/70r) | 70 | 77% vs 70% | 6% | ¥4.96 / ¥4.38 | 1.5 h |
Seiban–Higashi-Okayama (Kansai–Chugoku) 西播東岡山線・山崎智頭線 · AC 500kV | KNS → CGK | 4,164 / 4,494 | -2,963 | 0 | 66% | 95% | 10.3% | 2.5 (0f/129r) | 16 | 70% vs 10% | 46% | ¥6.00 / ¥0.58 | 1.0 h |
Anan–Kihoku HVDC (Kansai–Shikoku) 阿南紀北直流幹線 · HVDC | KNS → SKK | 0 / 748 | -745 | 0 | 100% | 100% | base flow | — | 47 | 47% vs 0% | n/a | ¥3.39 / ¥— | — |
Honshi (Chugoku–Shikoku) 本四連系線 · AC 500kV | CGK → SKK | 1,162 / 1,158 | -861 | 2 | 74% | 97% | 21.3% | 5.1 (0f/266r) | 38 | 74% vs 28% | 41% | ¥4.50 / ¥1.65 | 5.5 h |
Kanmon (Chugoku–Kyushu) 関門連系線 · AC 500kV | CGK → KYS | 449 / 2,262 | -1,382 | 2 | 62% | 97% | 13.1% | 3.1 (1f/163r) | 19 | 59% vs 13% | 40% | ¥2.88 / ¥0.55 | 0.0 h |
Forward = OCCTO 順方向 (from → to); for loop fences forward = export from the fenced area · Usable = operating capacity − margin (MW, mean over window) · Util. = mean |flow| ÷ usable in the direction of flow · Congested = slots at ≥ 95% · Split = JEPX day-ahead prices of the two areas differ · Explained = share of split slots during which this link was congested · |Δ| = mean absolute price gap (¥/kWh) in congested vs uncongested slots
Frequency converters (50/60 Hz) · 連系線 detail
周波数変換設備 · forward = Tokyo (東京) → Chubu (中部) · price split vs TKO–CBU day-ahead · 2026-06-28 → 2026-09-25 (52 days)
Mean utilisation
69%
Congested slots
32.1% · 7.7 h/day
Mean flow
-110MW · 45% fwd
Usable fwd / rev
907 / 1,086MW
Splits explained by congestion
45% · split 39% of slots
|Δ price| congested / free
2.37 / 1.02¥/kWh · dir. consistent 53%
Slot profile · mean flow (MW) vs usable capacity · bars = congested share of days
- Congested fwd %
- Congested rev %
- Flow P10–P90
- Mean flow (+ = TKO→CBU)
- Usable fwd
- Usable rev
Daily congestion hours (fwd / rev) vs mean |price split| TKO↔CBU (¥/kWh)
- Congested fwd (h)
- Congested rev (h)
- Mean |Δ price|
Utilisation heatmap · last 60 days × 48 slots · cyan = forward (TKO→CBU), violet = reverse · intensity = % of usable capacity
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Since April 2026 the central AC loop (Chubu–Hokuriku–Kansai) is operated on area fences (中部・北陸・関西フェンス): each fence is the net flow across that area's boundary with the other two loop areas, so the Chubu and Kansai fences are compared against the Chubu–Kansai price split and the Hokuriku fence against Kansai–Hokuriku. Source: OCCTO 系統情報サービス 連系線潮流実績 (5-minute actual flow, operating capacity 運用容量, margin マージン, planned flow 計画潮流 and available transfer capacity 空容量 per tie-line), aggregated to JEPX 30-minute slots. Forward (順方向) is OCCTO's convention for each link (from → to). Usable capacity = operating capacity − margin in the direction of flow; utilisation = |flow| ÷ usable; a slot is congested when utilisation ≥ 95%. A link that sits at ≥95% in ≥95% of slots (e.g. the Anan–Kihoku HVDC, scheduled at its operating capacity) is flagged as base flow and excluded from the congestion KPIs. Price split = JEPX day-ahead price of the importing area minus the exporting area for the same slot; 'explained by congestion' = share of split slots (|Δ| > ¥0.005) between the two adjacent areas in which the link between them was congested.