System Resilience Against Major Earthquakes ~Learnings from the Hokkaido Blackout~
May 14th 2019 Manabu Nabeshima 1. Background
2. Fact-sharing
3. Implication
1 Where Hokkaido is
2 International comparison of US the grid size 770GW (Summer Peak Load)
Western Grid Eastern Grid EUROPE 131GW 469GW 581GW
France 93GW ERCOT (Texas) 64GW
Germany 77GW UK 62GW Japan 131GW Hokkaido Tokyo 57GW 4GW
Kyushu US: EIA Annual Energy Review 2012 16GW Europe: ENTSO-E Statistical Factsheet 2017 Japan: METI Demand and Supply Review Nov 2018 3 Interconnection between control areas
Japan has limited interconnection capacity between the 9 control areas.
Frequency in West: 60Hz Frequency in East: 50Hz
Hokkaido 5 GW
DC Tie line 0.9GW
Hokuriku Tohoku 1.8GW 5 GW 14 GW 4.15GW Chugoku Kansai BTB 0.3GW 5.3GW 11 GW 26 GW 2.5GW 2.37GW Chubu Tokyo 1.2GW DC Tie line 1.4GW 25 GW 50 GW Kyushu Shikoku FC 15 GW 5 GW 1.2GW
*DC: direct current, FC: frequency conversion
4 1. Background
2. Fact-sharing
3. Implication
5 Demand scale when the earthquake hit
The earthquake hit Hokkaido when the demand was relatively small
6 The epicenter of the earthquake
The epicenter was close to Tomato-Atsuma thermal power plant
Grid map of Hokkaido Source of supply before the EQ
Generation type Output (MWh) Share
Nishi-nayoro Thermal 1,725 (1,492 from 56% Tomato-Atsuma)
Asahikawa- Hydro 780 arashiyama 25% Nishi-taki kawa Naie Nishi- tobetsu Wind 166 Nishi-asahikawa 5%
Doo-kita Sunagawa Tomari Shinoro (Nuclear) Doo-higashi Solar 0 Tomari Nukabira 0% Kita-ebetsu
Nishino Nishi-sapporo Minami- Nukabira- Ashinuka sapporo shintoku Shintoku-oiwake Eniwa-nansatsu Oiwake- Ashoro Interconnection 72 Kyog oku Kita-shintoku 2% Doo-nishi Eniwa eniwa Shiribeshi Karikachi Tomakomai Hakodate Futaba Niikappu Oi wake Uenbetsu Nishi-futaba Others 344 Minami-hayakita 11% Niikappu Tomakomai Nishi- kyodo Hidaka Date muroran Minami- Iwashimizu Takami Donan Muroran hayakita Total 3,087 Tomato-a t s u ma Tomakomai
Doo-mi n a mi Kita-nanae Tomato-atsuma
Ono Hakodate
Kamikita Hokkaido-Honshu HVDC Link Red: Operating Shiriuchi Black: Shut down Epicenter of EQ 7 Sequence of events that led to the blackout 3 units at Tomato-Atsuma (N-3) shut down 4 power transmission lines (N-4) were damaged by ground fault. The UFR* and interconnection were insufficient to sustain the frequency *UFR: Under Frequency Relay
8 Tomato-Atsuma power plant
Transmission accident
Earthquake vibrations caused the [1] jumper wire to come in contact with the [2] tower body 9 Recovery from the blackout
It took approx. 45 hours to supply power to nearly the entire area
Time Series Incidents after Blackout to Power Restoration Investigated and Fact-verified by the Investigation Committee 3,500 03:25 Hokkaido 02:04 Blackout NSSMC generator parallel in
04:00 The first black start in the main grid: 03:46 Takami 1 parallel in Shiriuchi 1 parallel in
3,000 04:24 06:21 The first black start failed: Naie 1 parallel in Takami 1 shut down
06:30 The second black start in the main grid: Niikappu 1 parallel in 06:37 Niikappu 2 parallel in 2,500
13:35 Sunagawa 3 parallel in 19:18 Date 2 parallel in
20:10 2,000 Onbetsu 1 parallel in (stop at 06:36, Sep. 7) 21:00 Started power receiving from Hokkaido-Honshu HVDC Link (600 MW)*
） ※gradually increase inflow to maintain 00:20 supply-demand balance
MW Naie 2 parallel in （ 22:24 Hakodate area customer load fully restored 1,500 22:48 Sapporo area customer load fully restored 00:57 Sunagawa 4 parallel in
Capacity 05:30 Started power receiving from 23:17 Asahikawa area customer load fully restored Hokkaido-Honshu HVDC Link (300 MW)* ※gradually increase inflow to maintain supply-demand balance 11:43 00:10 Tomakomai area customer load fully restored 1,000 Customer load 00:13 Kushiro area customer load fully restored restoration start 09:08 (on the main grid) Onbetsu 2 parallel in
11:17 Date 1 parallel in 500 Supply capacity(calculated based on parallel in time and rated capacity) Demand
Receiving capacity of Hokkaido-Honshu HVDC Link 0 9/6 00:00 06:00 12:00 18:00 9/700:00 06:00 12:00 18:00 9/800:00 06:00 12:00 18:00 9/900:00 Although the main grid lost power supply, other isolated grid Time such as Kushiro or Asahikawa, continued black start operation. Demand and supply capacity are calculated based on HEPCO generators' rated capacities, output and time of parallel in which could be operated on line. Demand is
Approx.45 Hours 10 Voluntary power saving
METI asked the citizens of Hokkaido to cut back electricity demand from 8:30 to 20:30 and 10~20% of reduction was achieved
*Demand is measured against the peak demand during Sep.5th, the day before EQ 11 Measures to be taken
✔ Expansion of the interconnection capacity
✔ Addition of load shedding capacity (UFR: Under Frequency Relay)
✔ Ensuring resource adequacy
12 1. Background
2. Fact-sharing
3. Implication
13 Implication to Renewable Energy Sources (RES)
✔ On-site PV contributed to support household demand. Educating the citizens on how to modify the device setup is important
✔ Clear grid code is required to make RES more resilient to frequency changes
✔ Sufficient balancing capacity is required for RES to re-connect to the grid after blackout
14 Contribution of on-site Solar Photovoltaic (PV)
METI announced how to modify the device setup to run in power from the on-site PV
Announcement from METI
Share of households utilized on- site PV during the blackout
85%
15 Resilience against frequency changes
Due to mechanical configuration, 170MW of wind power tripped all at once when the frequency dropped below approx. 47.0Hz.
Frequency fluctuation and response status
• 170MW of wind power 1,000MW tripped when the frequency dropped to current Honshu approx. 47.0Hz Frequency - Hokkaido
[Legend] Hokkaido frequency Hokkaido-Honshu HVDC Link current 0MW (Kitahon-nanae line) 16 Recovery of RES
It took a week for RES to recover to full operation due to lack of balancing capacity
Margin at the Recovery of MW interconnection Kyogoku was secured pumped hydro
Extra-high voltage PV +380 MW All wind 定格出力 +280 MW 定格出力（接続済） High voltage PV +590 MW
Extra-high voltage PV w/battery +100MW Wind w/ battery +100MW Low voltage PV +310MW
Sep. 8th (Sat) Sep. 9th (Sun) Sep. 11th (Tue) Sep. 14th (Sat) 7am 3am 9am 16pm 17