FUTURE VISION OF TRANSMISSION AND DISTRIBUTION 2030

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1 FUTURE VISION OF TRANSMISSION AND DISTRIBUTION 2030 Kyoichi Uehara Claus Kern Joseph L. Koepfinger Toshiba Corporation Japan Siemens Germany J.L. Koepfinger Consulting United States Mark Waldron Guangfan Li JongWoong Choe National Grid United Kingdom CEPRI China Encored Technologies ABSTRT This paper describes the work of the IEC TAD TF of future vision of T&D Penetration of renewable energy (Photovoltaic generation and Wind power) continues to increase rapidly. Accordingly, T&D systems have to expand and develop, including the adoption of countermeasures to stabilize the fluctuation of frequency and voltage of the power system. Voltage control of distribution systems and management of reverse current flow have already been implemented and large scale electric batteries are now being verified for application in transmission substations. HV and UHV transmission will also continue to be important technologies and are described in this paper. INTRODUCTION IEC TAD (=Advisory Committee on Electricity Transmission And Distribution) is tasked with summarizing the future vision of T&D systems and Emerging technology up to Information from several major regions has already been summarized and further information from the Middle East, Africa and South America will be incorporated to create a truly worldwide view. It is already clear from recent surveys that each region has a different future vision concerning T&D systems but recurring key words are grid or transmission (multiterminal system including breaker), renewable energy, and UHV /UHV transmission.. PRESENT SITUATION OF T&D SYSTEM According to World Energy Outlook 2012 [1], T&D investment (additional capacity to meet higher demand, refurbishment and replacement of existing assets) will continue because of increasing electricity demand in developing countries and large renewable energy adoption in developed countries for future. Particularly nonoecd countries will invest twice as much as OECD countries. Figure 1 shows that the investment for T&D systems are relatively large compared with others. *Other includes geothermal, concentrating solar power and marine. Figure 1 Power sector cumulative investment by type in the New Policies Scenario, [1] RENEWABLE ENERGY AND T&D SYSTEM The Fukushima nuclear disaster further accelerated the development and integration of large amounts of renewable energy into T&D systems. In particular investment in onshore and offshore wind turbine generation and Photovoltaic generation has grown rapidly all over the world. Depending on the scenario adopted, nonhydro renewables rise from 5% of total electrical energy production in 2012 to somewhere in the range between 12% to 31% by [2] Figure 2 shows incremental electricity generation from renewables in selected regions, Figure 2 World electricity generation by source in the New Policies [2] Growth in energy production and use is particularly rapid in China and this includes a major growth in renewable energy, particularly from wind. Due mainly to the huge CIRED /5

2 distances over which large capacity power transfer is required, this electricity will be transmitted by UHV transmission systems, employing a combination of both UHV and UHV. Figure 3 shows one example of off shore capacity development targeted in main European, Asian, and U.S. areas by Figure 3 Offshore capacity development targeted in main European, Asian, and U.S. areas by 2020 (The National Renewable Energy Laboratory (NREL), DOE, USA) [3] control utilizing tap control and SVC 3) A need for electrical energy storage systems to stabilize voltage and frequency of the power system, potentially at high cost HV TRANSMISSION SYSTEM AND GRID HV transmission is expanding for offshore electricity transmission, electricity transmission between islands or different frequency areas and longdistance and largecapacity electricity transmission between demand and supply areas. Growth in HV transmission, and particularly the prospect of genuine multiterminal HV transmission systems, introduces a need for technological developments such as HVGIS, circuitbreakers fast, discriminating protection systems and new control philosophies to cater for greater integration of & systems. Figure 5 shows the transmission network plan in Europe where transmission will increase and the HV multi terminal system might appear including breakers. According to the ten Year Network Development Plan 2014(TYNDP2014)[4], more than 20,000km of transmission lines & cables are planned due to huge offshore wind energy transmission (mainly North Sea) and long distance, largecapacity transmission in Europe. The use of subsea cable for HV is forecast to increase remarkably in this area. Figure 4 shows the recent rapid Japanese PV installation due to the introduction of a feed in tariff adoption. PV investment surged 56% to $35.4bn in 2013 from $22.7bn in PV accumulated capacity in 2030 is forecasted around 3 times the installation from 2012 to Figure 5 10Year Network Development Plan from 2012 to 2022 [6] UHV TRANSMISSION SYSTEM The use for UHV transmission is predicted to grow where there is a need for high capacity, long distance transfer of electric energy. Table 1 shows the Chinese plan of UHV & transmission system and wind power. Figure 4 PV generation outlook up to 2030 in Japan [5] Table 1 Chinese UHV transmission system plan & largescale wind power invest capacity This rapid increase in PV brought some issues to the existing distribution system and transmission system: 1) Reverse power flow through transformers requiring a different approach to tripping the secondary circuit breaker 2) Installing power flow meters in secondary of transformers and implementing more accurate voltage Year UHV & transmission network (UHV 1000kV, UHV 800kV) vertical and 2 horizontal UHV backbone lines, 7 UHV lines vertical and 5 horizontal UHV backbone lines, more UHV lines Station capacity (GVA) Wind power capacity (GW) 4, , CIRED /5

3 EMERGING TECHNOLOGY FOR FUTURE Based on input from the IEC Technical Committee (TC) representatives related to T&D system, TAD summarised the emerging innovative technology up to 2030 in Table 2. At the beginning of this future technology discussion, the target was 2050, but it was very difficult to imagine the emerging innovative technology up to 2050, so the target was reviewed to 2030, particularly on communication technology. Table 2 IEC TC related Emerging Technologies in Transmission and Distribution [7] IEC Technical Committee 2014 >2020 >2030 (HV/HV) TC8 (Systems aspects for electrical energy supply) TC13 (Electrical energy measurement, tariff and load control) TC14 (Power transformers) SC17A/SC17C (SWITCHGEAR & CONTROLGEAR) TC20 (Electric cables) TC22,SC22F (Power electronic systems and equipment) TC28 TC36 (Insulators) TC37 (Surge arresters) The adoption of long distance and large capacity transmission system LCCHV => High power capability VSCHV=>Lower power capability IEC DLMS/COSEM suite => New smart metering applications and security requirements Extension of scope for metering. NWIP on metering accepted (13/1510/RVN) Onsite assemble EHV & UHV transformers Environmental & fire safety transformers UHV converter TR Medium voltage switchgear: compactness and withstand to harsh climatic conditions including flooding are more and more required in public distribution., Short Circuit current increase up to 80kA R&D of circuit breaker started UHV transmission system expands Development of UHV system standards VSCHV Cap Increase (80% HV:VSC), Standard Voltage HV Transmission => Grid + breaker IEC 62052/62053 => Adaptation to new electronic metering technologies; adapting to changing EMC environment. IEC DLMS/COSEM suite => harmonizing application model and communication profiles for smart electricity, gas, water, heat and consider advanced endtoend data security Modeling of metering related applications Wide spread of onsite assemble EHV & UHV transformers Wide spread of Environmental & fire safety transformers Onshore /off onsite assemble UHV converter TR Medium voltage : VCB share increase High voltage: SF6 GCB continues Application of grid circuit breaker in multiterminal HV grid or grid Widespread UHV transmission systems (crosscountry) Intersection for Grids Integration of grids & grids Interoperability of grids Increase of Multiterminal HV and grids>ehighway Voltage and current transformer operated meters using new measuring instrument transformer technologies. Integration of smart meters into M2M and Internet of Things environment. Operation transformer equipped semiconductor type OLTC Operation Superconductivity Current Limiter & TR Wide spread of Onshore /off onsite assemble UHV converter TR Wide spread of breaker in grid and multiterminal HV system Up to 500kV cable Up to 800kV cable Up to 1200kV cable HV system (On shore off shore )MI cable mainly applied ±320kV > ±400kV HV insulation coordination Composite Insulator application Pollution criteria review Preparing for Arrester standard HV system (On shore off shore )MI cable > XLPE Cable Max rating : ±500kV2000A Cable Hybrid CB and other fault current interrupting means Interface of a.c. systems and energy storage systems Preparing the standardization of equipment rated voltage and current, testing LI, SW, voltage Wide spread of Composite Insulator application Integration of MOSA with distribution equipment High field MO resistors for bridge arresters Wide spread of XLPE Cable Max rating : ±800kV2000A Cable VSC HV based city in feed systems Standardization of equipment rated voltage and current, testing LI, SW, voltage Field grading with micro varistors Composite varistors Wide spread of LSA for transmission lines Charge release from insulators with micro varistors CIRED /5

4 IEC Technical Committee (HV/HV) TC38 (Instrument transformers) TC57 (Power Systems Management and Associated Information Exchange) TC90 (Superconductivity) TC95 (Measuring relays and protection equipment) TC115 (High Voltage Direct Current (HV) transmission for voltages above 100 kv) & specific Digital VT/CT Fiber optics VT/CT Optical CT Kraemer type CT 2014 >2020 >2030 Overall architecture for information exchanges for electricity grids, and related standards (control, protection, asset management, DA, EMS, market, cyber security, etc.) CIM (common information model) for HV links Wide spread Digital VT/CT Wide spread of Optical CT Architecture exchange extension to: Cross cutting applications (Demand / response; Voltage control ) Mesh grids (HV & ) Interfaces with Home & Buildings information and control systems for cyber security end to end solutions to TC57 standards. CIM for HV multilinks (asset management, operation, control) for HV station control, operation & protection 66kV275kV cable, current limiter? Transformer? transmission system Expand of transmission system IEC 61850, Local Area Protection >Wide Area Monitoring System VSCHV increase Max rating ±320kV ±800kV 7,200MW LCC HV power transmission systems ±320kV 800MW VSC HV power transmission systems Wide spread of Wide Area Monitoring System / Wide Area Monitoring Protection and control / New functions for loss of mains detection Specific protection for lines HV transmission system expands Max rating ±800kV Preparation for the HV system standards ±1100kV LCC HV power transmission systems power tapping Wide spread Digital VT/CT Expand of transmission system, 500kV cable? Wide spread of Wide Area Monitoring Protection and control HV transmission system expands Max rating : ±1200kV Preparation for the HV system standards incl. CB. grids Current trends and new technologies in T&D field are shown in Table 3. Table 3 Current trends and new technologies in T&D field Current trends and new technologies Related IEC TCs & SCs and others International and national policies that encourage low carbon society IEC MSB(Smart electrification) TC65 transmission system adoption includes new technology application TC8, TC22, SC22F, TC115 in Table 2 (HVVSC, grid, multiterminal grids) Progress in technology includes Information and Communication Technology TC13, TC57 in Table 2 Asset management particularly needs the investment in endoflife grid IEC MSB Strategic Management of ageing assets Power networks Evolution of the T&D market design, regulatory mechanisms and wide area TC8, TC57, TC95 in Table 2 operation to meet the recent requirement of the power system FUTURE TRENDS From recent research and surveys it is clear that there are some universal trends that characterize the development of T&D systems over the next 1520 years. In summary, these are the greater use and integration of renewable sources, greater levels of interconnection including the growth of UHV transmission systems and the development of more active & intelligent distribution systems. The relative importance of these and the means of implementation varies on a regional or even a national basis related to local regulation and political issues but the reduction of CO 2 emissions as part of the development of a more sustainable society is important everywhere. In relation to these trends and the future vision of transmission and distribution systems, the following issues are pertinent when considering emerging innovative technologies (shown in Table 2) 1) The use of electric energy will continue to increase, both to meet the demand of increasing population and to facilitate the development of a sustainable society. CIRED /5

5 T&D systems remain crucial for the integration & balancing of generation and consumption locally and also over large regional areas. Rapid growth of renewable energy, such as the development of offshore wind in the North Sea, will certainly require technological developments such as higher capacity HVVSC and longer submarine cables and is also likely to drive the development of multiterminal HV transmission systems incorporating HV Circuit Breakers. The growth of wind power in China differs in that it is in the north western area which is very far away from the main centers of consumption in the east. The following technologies facilitate these large power transfers: Higher voltage level transmission: UHV More flexible transmission: FTS Higher voltage level transmission: UHV Relating to emerging HV transmission system, it seems to be necessary to standardize the HV system to consider future multiterminal HV system. 2) Greater penetration of dispersed generation into distribution systems has required a change in how they are considered. Rather than being passive loads distribution systems must now be considered as active parts of the overall T&D system. In particular reverse flow of current from the dispersed generation (Photo Voltaic etc.) requires some counter measures such as voltage control and disconnecting procedure of these sources. To reduce the fluctuation of voltage and frequency due to large amounts of renewable energy, there are some additional counter measures as follows: Addition of SVC in distribution system Installation of largescale battery systems. Figure 6 shows one counter measure: a largescale battery system in substation. At present this capacity is the largest in the world. CONCLUSION 1) T&D vision by 2030 is influenced by increasing large renewable energy in power system. 2) There are some gaps between market needs and standardization in the case of HV transmission system, Multiterminal HV system, and HVGIS system, grid for the future. 3) Coordination control & protection between grid and grid will be necessary. 4) Electrical Energy Storage system in substation will be some countermeasures for stabilizing power system. 5) UHV / system will expand, but some UHV system approach activity will start. There are no gaps between market needs and standardization in the case of UHV grid. Acknowledgments Authors acknowledge TAD chair and other TC representatives to discuss the Emerging Technologies in Transmission and Distribution. This paper describes the part of this issue. REFERENCES [1] WORLD ENERGY OUTLOOK, 2012, International Energy Agency, Paris, France, 195 [2] WORLD ENERGY OUTLOOK, 2014, International Energy Agency, Paris, France, 208 and 215 [3] IEEE Power& Energy, November / December 2013, Piscataway, NJ USA, 8383 [4] 10YEAR NETWORK DEVELOPMENT PLAN 2014, 2014, ENTSOE, Brussels, Belgium, 69 [5] JPEA PV OUTLOOK 2030, Dec. 2012, Japan Photovoltaic Energy Association, Tokyo, Japan 3 [6] IEEE Power& Energy, November / December 2013, Page 87 [7] TAD/45/INF, Information on "Emerging technologies in related TCs, IEC TAD meeting , New York, USA Figure 6 Largescale Electrical Battery Systems (NishiSendai Substation, Tohoku Electric Power Co.) 1) 40 MW20MWh installed at 500/275/154/66 kv Substation (60mwide 100mdepth) Started operation from Feb (Under verification tests) CIRED /5