Active Distribution Networks - Microgrids

1 1 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Active Distribution NetworksNikos GreeceRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 PhotovoltaicsFuel CellsMicroturbinesReciprocating EnginesDistributed Generation TechnologiesAdvanced TurbinesThermally Activated TechnologiesExamplesWind2 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005-3 Manuel SANCHEZ European Commission BETA SESSION 4b: Integration of RES+DG Barcelona 12-15 May 2003 YesterdayTomorrow:distributed/ on-site generation with fully integrated network managementStoragePhotovoltaicspower plantWindpowerplantHouse with domestic CHPP owerqualitydeviceStorageCentral power stationHouseFactoryCommercialbuildingLoc al CHP plantStorageStoragePowerqualitydeviceFlo wControlThe NetworkDistribution NetworkPassive and Active Distribution NetworksPassive Distribution Networks Designed to accept bulk power from transmission system and distribute to customers Real time control problem resolved at planning stage Ad hoc approach with existing practise ( fit and forget ) No control over DER Limiting capacity of DER to be absorbed by the existing networksRural network : voltage riseUrban network .

2 Fault levelActive Distribution Networks Local and coordinated control of voltage, flows and fault levels3 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Active Distribution network OPERATION Advanced DMS for supervision, control & operational planning Active & Reactive Power Support (ancillary services) Islanding & Blackstart capabilities MicroGridsACTIVE Distribution network PLANNING network Reinforcement vs DG development Methods and new Tools for Design Harmonized StandardsRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Active Distribution network OperationAP,-QCHPSpvP+/-QP,+/-Q D M SControllerP,Q,V, P,Q,V, P,Q,V, 4 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Current approachCurrent approachNetwork Security & PlanningGeneration solution to network contribution ignoredProposed approachProposed approachGGroup Demand 120 MW100100T3 GGroup Demand 120 MW10010050 MWGenerator contribution recognised50 MWIssues for Active Distribution Networks Need to understand and demonstrate the value of flexibility and controllability Technical benefits (security, reliability)

3 Economic benefits (cost savings, competitiveness) Need to quantify the benefits of: Enhanced security Displaced central generation capacity Reduced network investment Reduced generation operating costs Reduced outage costs Increased competitiveness of DER Need to explore alternative network control approaches Control of network topology (switching technology) Coordination of operation of network control facilities Coordinated (but decentralised) control of DER5 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005DG Interconnection Technologies Plug & Play capabilities Active and reactive power support Load Sharing Fault Ride Through Capability Fault Current Contribution Power Quality Improvement, Active Filtering Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Microgrids Future ParadigmInterconnection of small, modular generation to low voltage Distribution systems forms a new type of power system, the Microgrid.

4 Microgrids can be connected to the main power network or be operated islanded, in a coordinated, controlled Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005EU Microgrids ProjectGREAT BRITAIN UMIST URENCOPORTUGAL EDP INESCSPAIN LABEINNETHERLANDS EMforceGREECE NTUA PPC /NAMD&RESD GERMANOSGERMANY SMA ISETFRANCE EDF Ecole des Mines de Paris/ARMINES CENERG Large Scale Integration of Micro-Generation to Low Voltage GridsContract : ENK5-CT-2002-00610 ARMINESCENERGISETICCS / NTUAGERMANOSEDFSMAUMISTURENCOPPC/NAMD&RE SDLABEIN14 PARTNERS, 7 EU COUNTRIESINESC Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Technical, economic and environmental benefits of Microgrids Energy efficiency Minimisation of the overall energy consumption Improved environmental impact Improvement of energy system reliability and quality of service network benefits Cost efficient electricity infrastructure replacement strategies7 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens.

5 13thApril 2005 Potential for Microgrids to improve service qualityGGGDGGGGDGDG-Mediumscale DGCentral generationSmall-scale DGVoltage levelSecurityof supplySecurityof supplyDistribution of CMLsRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Technical Challenges for Microgrids Relatively large imbalances between load and generation to be managed (significant load participation required, need for new technologies, review of the boundaries of Microgrids ) Specific network characteristics (strong interaction between Active and reactive power, control and market implications) Small size (challenging management) Use of different generation technologies (prime movers) Presence of power electronic interfaces Protection and Safety8 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Market and Regulatory Challenges coordinated but decentralised energy trading and management market mechanisms to ensure efficient, fair and secure supply and demand balancing development of islanded and interconnected price-based energy and ancillary services arrangements for congestion management secure and open access to the network and efficient allocation of network costs alternative ownership structures, energy service providers new roles and responsibilities of supply company, Distribution company, and consumer/customerRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Microgrids Highlights Control philosophies (hierarchical vs.)

6 Distributed) Permissible expenditure and quantification of reliability benefits Device and interface response and intelligence requirements Energy management within and outside of the distributed power system Steady State and Dynamic Analysis Tools 9 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Microgrids Hierarchical ControlMicroGrid Central Controller(MGCC) promotes technical and economical operation, interface with loads and micro sources and DMS; provides set points or supervises LC and MC; MC and LC Controllers: interfaces to control interruptible loads and micro sources Centralized vs. Decentralized ControlMVL VDMSDMSMGCCMGCCDCACPVMCLCMCACDCLCS torageLC~CHPMCM icro Tur bineMCFuel CellMCACDCLCACDC~F l yw heelMCACDCR ound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 MultiAgent System for Microgrids Autonomous Local Controllers Distributed Intelligence Reduced communication needs Open Architecture, Plug n Play operation FIPA organization Java Based Platforms Agent Communication LanguageMicrogrid Microgrid.

7 Microgrid MOMGCCLC LC AgentAgentAgentAgent AgentAgentAgentAgentGrid LevelManagementLevel Field Level 10 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Highlight: Permissible expenditureto enable islandingCustomer Sector:Residential CommercialAnnual benefit = 2 /kWpk25 /kWpkNet present value =20 /kWpk250 /kWpkPeak demand =2 kW1000 kWPerm. expenditure = 40 250,000 Microgrid (2,000kW) 40,000 500,000 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Highlight: Reliability AssessmentFLOL (ev/yr) LOLE (hrs/yr) LOEE (kWh/yr)Infeed Capacity 100% (no DGs) 2,130 23,93 2279,03 Infeed Capacity 80%(no DGs) 58,14 124,91 3101,52 Infeed Capacity 80%(with Wind + PV) 14,02 41,67 2039,41 Infeed Capacity 80%(all DGs) 2,28 15,70 716,36 System Maximum Load Demand: 188 kW Capacity of System Infeed:210 kW (100%) Installed DGs.

8 15 kW Wind, 13 kW PVs, 30 kW Fuel Cells, 30 kW Microturbines11 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Microgrid Serving its own needs using its local production, when financially beneficial(Good Citizen)(Good Citizen)MGCC minimises operation costs based on: Prices in the open power market Forecasted demand and renewable power production Bids of the Microgrid producers and consumers. Technical constraints Microgrid buys and sells power to the grid via an Energy Service provider (Ideal Citizen)(Ideal Citizen)MGCC maximizes value of the Microgrid, maximizes revenues by exchanging power with the grid based on similar inputsParticipation of Microgrids in Energy MarketsRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Study Case LV Feederwith DG kVuk=4%, rk=1%, Dyn1120 kV, 50 Hz, 400 kVA3+N3 20 kVOff-load TC19-21 kV in 5 steps80 10 80 3x70mm2 Al XLPE + AAACT wisted Cable30 m80 80 80 80 Single residencialconsumer3 , Is=40 ASmax=15 kVAS0= kVA4x6 mm2 Cu20 m4x25 mm2 Cu3+N3+N+PE3+N+PE20 m30 30 m4x16 mm2 Cu2 Possible neutral bridgeto adjacent LV network80 80 20 mSingle residencialconsumer3 , Is=40 ASmax=15 kVAS0= kVAGroup of 4 residences4 x 3 , Is=40 ASmax=50 kVAS0=23 kVA3+N+PE1+N+PE3+N+PE3+N+PE3+N+PEAppartm ent building5 x 3 , Is=40 A8 x 1 , Is=40 ASmax=72 kVAS0=57 kVAAppartment building1 x 3 , Is=40 A6 x 1.

9 Is=40 ASmax=47 kVAS0=25 kVA3x50 mm2 Al +35mm2 Cu XLPEPole-to-pole distance = 35 mOverhead line4x120 mm2 Al XLPE twisted cable80 Other lines4x6 mm2 CuFlywheel storageRating to bedetermined~~~Microturbine3 , 30 kWPhotovoltaics1 , 3 kW30 Photovoltaics1 , kW~Wind Turbine3 , 15 kWCircuit Breakerinstead of fuses80 30 m4x16 mm2 CuFuel Cell3 , 30 kW10 ~Circuit BreakerPossible sectionalizing CB12 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Highlight: MGCC Simulation ToolRound Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Good Citizen Cost Reduction : % 27% reduction in CO2 emissions Model Citizen Cost reduction : & Power exchange with the grid (residential feeder)-30-20-1001020304050607080901 2 3 4 5 6 7 8 9 1011 1213 1415 161718192021 2223 24 HourkWPow er exchanged w ith the gridLoad PatternResidential Feeder with DGs13 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Parallel Operation of Invertersuu01-1 QQN-4%u0 ff001-1-1%PPNf Frequency droopVoltage droop- Droops for synchronising inverters with frequency and voltage- Frequency and voltage of the inverter is set according to Active andand reactive Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Highlight.

10 Electronic Switch-300030040042044046048050052054056 0580600-100-80-60-40-2002040608010040042 0440460480500520540560580600-1000-800-60 0-400-20002004006008001000vMicroGrid [v]islandgrid connectedIMicroGrid [A]tim e [m s] IGrid [A]14 Round Table The Effect of Distributed and Renewable Generation on Power Systems Security , Athens, 13thApril 2005 Highlight: Modeling and SimulationTwo battery invs + two PVs + one WT - Isolation + wind fluctuationsP,Q per phase Battery Inverter A I per phase Battery Inverter AConclusions Open Issues for Active Distribution Networks -Planning and operation standards of Active Distribution Networks -Deployment rates of DER and need for new enabling technologies-Criteria for provision of system security services by Active Distribution Networks -Strategies and technologies for coordinated network and generation control (energy transfer control, control of voltage, fault level and topology)-Grid Code requirements for Active Distribution Networks and generation interface requirements-Service quality and outage cost performance of Active Distribution Networks