i-pcgrid2017 Japanese Energy Industry Transformation - Challenges to use facilities radically for extra efficiency Yasutomo Johraku Power System Protection Engineering Group Power System Operation Department TEPCO Power Grid, Inc
Introduction Who are we? Power Demand and Sales Established in May 1, 1951 Electricity sales Maximum output 247,100 GWh (FY2015) 54.86 GW (Aug 9, 2016) 64.3 GW (July 24, 2001) Power Stations Generation Total Hydropower (14.5%) Thermal Power (66.0%) Nuclear (19.4 %) Renewables (0.1%) Network Apparatus Transmission Lines Overhead Underground Substations (1,579 sites) Distribution Lines Overhead Underground 195 sites/66.06 GW 164 sites/ 9.86 GW 25 sites/ 43.56 GW 2 sites/ 12.61 GW 4 sites/ 0.03 GW 28,405 km 12,340 km 269.3 GVA 336,505 km 37,384 km Main Service Area: Tokyo metropolitan area TEPCO group covers: - 10% of Japan s land area (39,512k m2 ) - 35% of Japan s population(45 million people) - 32% of Japan s electricity sales 1
Introduction Need strong driving force to cost reduction TEPCO group s situation The Great East Japan Earthquake in 2011 Fukushima nuclear power plants were destructed TEPCO group have to pay $3.4 billion(usd) every annual year Compensation for Fukushima Decommissioning reactors in Fukushima Decontamination in Fukushima TEPCO group MUST Maximize income Minimize outgo Reasonable efficiency is not enough. EXTRA efficiency is required. before Fukushima nulear power plant After 2
Today s presentation 2 Challenges to use facilities radically for EXTRA efficiency Remedial Action System(RAS) against thermal overload using GOOSE message Dynamic Transformer Rating(DTR) 3
Over load caused by increasing renewable energy Increasing renewable energy causes heavy load TEPCO s power system : double transmission lines 1 Single line goes down due to a fault 2 Another circuit line gets overload and trip 3 Cause wide area outage 4
Advantages of RAS solution Ordinal solution Rebuild to bolder transmission lines Estimated cost is $120 million(usd) RAS solution For suppress money Detect overload, and shutdown generators (Send tripping signals via communication network) Less than 1/100 cost against ordinal solution Issues Many (tens) target generators exists Targets scattered in wide area (up to 150 miles away beyond the mountains) 5
Outline of RAS configuration Network data transmission protocol : GOOSE message Each devices : Apply IED 6
Other specialties Other specialties of our RAS using GOOSE message Number of Generator shedding devices is unlimited When communication network capacity is unlimited. (Approximately 20 devices /1.5Mbps) Automatic self testing function Checking contact output in test mode, at once every day (Separately from automatic monitoring function) Any malfunctions detected, noticed to operators Devices need no periodic inspection Multi vender connection Data bit assignment, data length, etc. in detail Conditions for RAS in multi vender connection created Devices are procurable by bidding 7
Conclusion about RAS against thermal over load using GOOSE message Increasing renewable energy Problem about thermal ampacity caused Ordinal solution is unsuitable (reinforcement of transmission lines) Apply RAS solution to save money RAS solution needs point to multipoint data transmission, and ability to send data to vast area. GOOSE message is suitable for this application and available for transmission using our existing communication network. Developed and build RAS against thermal overload using GOOSE message. And achieved EXTRA efficiency. The first system is currently under installation and will be in service on May, 2017. 8
Today s presentation 2 Challenges to use facilities radically for EXTRA efficiency Remedial Action System(RAS) against thermal overload using GOOSE message. Dynamic Transformer Rating(DTR) 9
TEPCO s bulk power network and Boso region 500 kv (1000 kv designed) 500 kv 275 kv Substation Hydro power plant Thermal power plant Nuclear power plant Kashiwazakikariwa nuclear power plants Fukushima nuclear power plants Tokaidaini nuclear power plant TEPCO Shin - toyosu Tokyo City Area (Load Center) 10
TEPCO s bulk power network and Boso region 500 kv (1000 kv designed) 500 kv 275 kv Substation Hydro power plant Thermal power plant Nuclear power plant Kashiwazakikariwa nuclear power plants Out of service Fukushima nuclear power plants Out of service Tokaidaini nuclear power plant Out of service TEPCO Tokyo City Area Shin - toyosu Oil (Load Center) LNG, LPG Boso region Total amount 22GW of generators are located. (mainly gas or oil fired thermal plants) 11
Boso #1 transformer operation Generators in Boso needs high rate operation (Nuclear power plants are out of service) Boso #1 transformer is required for 120% overload operation 120% overload operation is required. 12
Ordinal solution Additional transformer Additional transformer itself Needs countermeasure (due to increasing short circuit current) Reinforcement of bus bar structure Replacement of many (tens) circuit breakers Replacement of under ground cables 新京葉線 Estimated cost is Hundreds million USD 花見川 千葉中央 新京葉 500kV 新佐原 Suppress generator output Generator output of Boso region has fairly good efficiency Suppress generator output of Boso means loss of money ( $0.9 million USD every annual year) 北千葉線 新豊洲線 275kV 北総 房総線 印旛線 Replacement 275kV of many circuit breakers for short circuit current upgrade Additional transformer Reinforcement of bus bar For short circuit current upgrade 500kV 房総 500kV 1U 2U 新木更津 500kV 君津線 275kV 275kV 内房 154kV 154kV Reinforcement of cables G G G G G G G G G G G G For short circuit current G G G 2 6 1 5 4 3 6 2 1 5 3 4 upgrade 3 4 5 五井火力姉崎火力五井火力君津共同火力 新佐原線 Sinsodegaurasen Both of solutions are unsuitable 富津火力線 袖ヶ浦火力 G 1 G 2 G 3 G 4 富津火力 G 3-1 G 3-2 G 3-3 G 3-4 G 1-1 G 1-2 13 G 1-7 G 2-1 G 2-2 G 2-7 G 4-1 G 4-2 G 4-3
Dynamic Transformer Rating (DTR) system Focused Nominal current capability Nominal current capability is calculated by Assuming high ambient temperature Continuously constant current Safe side value Between Nominal and Operational, any margin should exist DTR system s function Measure temperature and current Ambient and Oil temperature Transformer current Derives Operational current capability Derives Remaining time Remaining time to suppress generator output Remaining time to shutdown generator etc. Beyond nominal current capability operation becomes possible 14
DTR system configuration 15
Information provided to the operators Display snapshot (In the reality, it s displayed in Japanese language) Rating under normal condition Estimated operational running time with present current 12h 40m Operational current capability (continuous) 1300A(1123MW) Operational current capability (30min) Operational current capability (1h) Operational current capability (2h) Operational current capability (4h) Operational current capability (8h) Measured and calculated values Measured ambient temperature 54.5F (sensor #1) 55.4F (sensor #2) Measured oil temperature Measured current Calculated winding temperature 165.2F Calculated oil temerature 122.3F 117.5F ( a phase ) 122.2F ( b phase ) 116.2F ( c phase) 1315A (1136MW) 1550A(1339MW) 1480A(1279MW) 1420A(1227MW) 1370A(1183MW) 1330A(1149MW) Rating under emergency condition (caused by fault) Operational current capability (30min) Operational current capability (1h) Operational current capability (2h) Operational current capability (4h) Operational current capability (8h) 1690A(1460MW) 1570A(1356MW) 1470A(1270MW) 1400A(1209MW) 1350A(1166MW) Data received at 2017/3/29 15:30:24 Information under normal condition Present current: 1315A (1136MW) Continuous Capacity: 1300A (1123MW) Estimated operational running time: 12h 40m Information under emergency condition Warning: Emergency rate mode Remaining time to generator suppression: 0h 0m 4s Remaining time to generator tripping: 0h 44m 50s Remaining time to transformer self tripping: 0h 47m 00s Health of sensors Amb temp. sensor #1 fail 16
Effect of DTR system in Boso #1 transformer Boso #1 transformer can stand for more than 120% load No additional transformer is needed by using DTR system 負荷率 Rateed load 170% 160% 150% 140% 130% 120% 110% 100% 90% 80% 70% 60% 50% 40% 30% Boso #1 transformer DTR 変圧器ダイナミックレーティング試算グラフ Calculated Dynamic Rate (limited in short time) 連続可能負荷率 15 分 150 DTR 値 30 分 140 DTR 値 1 時間 DTR 値 130 2 時間 DTR 値 外気温 120 油温度 ( 演算値 ) 110 巻線温度 ( 演算値 ) 100 20% 0 10/8 10/9 10/10 10/11 10/12 負荷率 Calculated Dynamic 194F 90 Rate (continuous) 176F 80 158F 70 140F 60 122F 50 104F 40 32F Oct, 8th Oct, 9th Oct, 10th Oct, 11th Oct, 12th Ambient temperature Recorded transformer current Nominal rating of the transformer 212F 30 86F 20 68F 10 50F 温度 Temperature 17
Conclusion about DTR system Generators in Boso needs high rate operation (Nuclear power plants are out of service) Boso #1 transformer is required for 120% overload operation Ordinal solutions is unsuitable (additional transformer etc.) Developed DTR system to save money Derives operational current capability and remaining time Provides information for operators Beyond nominal current capability operation becomes possible Confirmed DTR system is suitable for our purpose. And achieved EXTRA efficiency. DTR system for Boso #1 has been installed and started to be in service since Dec. 2016. 18
Thank you for your attention. TEPCO Power Grid, Inc. 19