Increasing amount of DGs demands for continuous protection system audits and new protection schemes

Transcription

1 Increasing amount of DGs demands for continuous protection system audits and new protection schemes Always an Eye to Security

2 Prof. Dr.-Ing. Rainer Krebs Principal Expert Power Technologies Head of Protection and Control System Studies Siemens AG, Infrastructure & Cities Sector NC, Erlangen, Germany Honorary Professor for System Protection and Control Otto-von-Guericke University Magdeburg, Germany German Member in working groups of: IEC, CIGRE, IEEE, DKE, T&D Europe Board Member of VDE Bavaria Page 2

3 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 3

4 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 4

5 Transformation of the Electricity System Age of Coal 19th Century Unsustainable energy system Electrification of society 20th Century 21st Century Sustainable energy system Age of Coal Generation and load closely coordinated Coal hydro No environmental concerns * First electrical energy conversion 1866 by Werner v. Siemens Page 5 Environmental awareness

6 Transformation of the Electricity System New Electricity Age the Age of Integration 19th Century Unsustainable energy system 20th Century 21st Century Sustainable energy system The New Electricity Age Electricity will be the energy source with a power grid as backbone. Integrated energy system Load follows generation Generation controls load Renewable energy sources (solar, wind, hydro, biomass), clean coal, gas, nuclear No environmental concerns * ) ICT = Information and Communication Technologies Page 6 Environmental awareness

7 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 7

8 Challenges for Protection Systems of Smart Grids From Primary Energy Sources to Consumers Windparcs Onshore/Offshore Double fed ASM Voltage Source Converters Industries Large Motors, Generators Power Electronics Dynamic Loads Oil and Gas, Harborand Special Systems MVDC-SIPLINK LNG Page 8 Power Plants Large Generators Large Motors Auxiliary Systems Transmission Short and long lines, cables Distribution Transformers Various Switching Situations Diff. Busbar Configs DGs FACTS / HVDC Short-circuit Current Limiters

9 Challenges for Protection Systems of Smart Grids Relay Types of Nearly All Eras Must Be Coordinated SIPROTEC V1-V3 SIPROTEC V Control Numerical Protection Relays Analog Relays Electromechanical Relays Page 9

10 Challenges for Protection Systems of Smart Grids Relay Types of All Manufacturers Must Be Coordinated Page 10

11 Challenges for Protection Systems of Smart Grids System Protection and Short-Circuit Protection Normal Operation Without DGs, No changing SC dir., Stability Reserves Short-Circuits System Protection Short-Circuit Protection Problem area short-circuit can often not clearly be confined towards the problem area system operation. Design of the protection system and equipment selection follows standard company rules despite of new requirements defined by modern power systems. No consideration of system emergency situations during settings calculation Critical Operation High Loads, DGs, Changing Infeeds, Stability Limit Short Circuits No consideration of system changes and extensions no continuous settings update Page 11 80% of all blackouts and large disturbances are in conjunction with wrong or unselective short-circuit protection

12 Challenges for Protection Systems of Smart Grids RENEWABLES Bulk wind farms onshore and offshore are feeding transmission grids Smaller wind farms and large PV plants are feeding distribution grids Small roof PV plants feeding LV grid Energy infeed is predictable, Power infeed is not predictable Energy TRADE Energy market is deregulated TRANSMISSION SYSTEM EXPANSION Reduction of spinning reserve The transmission grids with a clear power transmission task are actually transformed into power exchange platforms Page 12

13 Challenges for Protection Systems of Smart Grids Predictability and Dynamics of Wind Power Example: Vattenfall Europe Transmission, Feb Power in MW 8000 Load Windpower infeed Wind Power forecast 4000 Error: -60% Error: +280% 0 03/02 10/02 17/02 24/02 Source: IfR, TU-Braunschweig, Vattenfall Europe Transmission, Feb Page 13

14 Challenges for Protection Systems of Smart Grids Predictability and Dynamics of Solar Power Sunny Day, April: 1,9 MWh Cloudy Day, April: 1,2 MWh Source: Michael Weinhold & friends Page 14

15 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 15

16 Protection System Audits with SIGUARD PSA Protection System Fingerprint Page 16

17 Protection System Audits with SIGUARD PSA Today: Use of Graphical Documentation of Relay Settings Page 17

18 Protection System Audits with SIGUARD PSA Today: Use of Graphical Documentation of Relay Settings Page 18

19 Protection System Audits with SIGUARD PSA Protection Security Assessment Magnetic Resonance Imaging Scanning System Network and Protection System Page 19 Finger-prints

20 Protection System Audits with SIGUARD PSA Protection System Improvement Magnetic Resonance Imaging Doctor makes analysis acc. to his experience and defined measures expert system or genetic algorithm or protection expert Adaptive Settings Finger-prints Page 20

21 Leitungen Lines Protection System Audits with SIGUARD PSA Protection System Fingerprint L-West-Grünwinkel L-Grünwinkel-Süd L-West-Mitte L-West-StoraEnso L-West-Heide L-Süd-Oberwald L-Ost-Uni L-Ost-Oberwald L-Ost-Mitte L-Ost-Blöße L-Nord-Uni L-Nord-Heide L-Nord-Blöße L1-E Fault Ik1E.dat - - Fehlerwiderstand Ohm relative Länge in % (Fehlerort) Rel. line length / % Fault Resistance < 2,5 Ohm 2,4 Ohm < 2,3 Ohm 2,2 Ohm < 2,1 Ohm 2,0 Ohm < 1,9 Ohm 1,8 Ohm < 1,7 Ohm 1,6 Ohm < 1,5 Ohm 1,4 Ohm < 1,3 Ohm 1,2 Ohm < 1,1 Ohm 1,0 Ohm < 0,9 Ohm 0,8 Ohm < 0,7 Ohm 0,6 Ohm < 0,5 Ohm 0,4 Ohm < 0,3 Ohm 0,2 Ohm < 0,1 Ohm 0,0 Ohm Protection relays trip correctly Schutzgeräte an dem zu schützenden Betriebsmittel lösen korrekt aus Page 21 Schutzgeräte an dem zu schützenden Betriebsmittel sollten in der zweiten Protection Zone auslösen, relays lösen ab bereits operate in der accelerated ersten Zone aus - und umgekehrt Schutzgeräte an dem zu schützenden Betriebsmittel lösen erst in der Protection relays operate delayed dritten Zone, oder einer höheren Zone, aus bei einem Fehler auf dem zu schützenden Betriebsmittel löst mindestens Protection relays overfunction Siemens ein nachgeordnetes AG Schutzgerät All mit aus rights (Überfunktion) reserved. Protection relays underfunction nicht aus (Unterfunktion) mindestens ein Schutzgerät an dem zu schützenden Betriebsmittel löst

22 Protection System Audits with SIGUARD PSA System-wide protection performance matrix Actual fingerprint 80 lines with 294 relays Selectively coordinated Page 22 Single-phase to ground fault

23 Protection System Audits with SIGUARD PSA Zooming into the FingerPrint Columns with the name and length of the line Detailed information about protection device operation (device name, tripping zone, tripping time) Fault location (% of the line length) Color of the fields depends on the efficiency of the fault clearing (see below) selective trip unselective trip(overfunction) no trip (underfunction) Page 23

24 Protection System Audits with SIGUARD PSA Relay Error Rate for all 294 relays at 1-phase fault Page 24

25 SIGUARD The Family of Power System Security Solutions The perfect supervision of your power system SIGUARD PDP Phasor data processor for gathering, archiving and analyzing PMU data measurement SIGUARD DSA Dynamic security assessment of the impact of contingencies in actual and future system states SIGUARD PSA Protection security assessment of the selectivity, sensitivity and speed of the overall system and generator protection Page 25

26 SCADA Snapshot Steady-State Network Database Search Algorithm Protection Database Protection Selector Contingencies Scenarios Automatic Contingencies & Settings START Computation p th Computation Engine Contingencies Interface SCADA RDC Protection Index Selection Fault Pattern Analysis and Evaluation Protection Simulator Selectivity, Speed, Security Adaptive Settings Δt,, > Result Database Monitoring SCADA SIGUARD PSA Visualization & Reporting SIGUARD Page 26 DSA Cockpit Rainer Krebs

27 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 27

28 Distribution System of a Small City No DG Installed, Radial System with Single Infeed 20 kv City network 7 MW 110 kv 40 MVA t>0.0s Utility > t>>0s t>1,5s I t>1.2s Housing area 0.5 MW t>0.9s M t>0.3s t>0.0s Industry 10 MW Protection selectivity by use of simple non-directional oc relays - Unique short-circuit direction, - Current / time grading with def. or IDMTL characteristics M Industry 3 MW Grading from load to infeed with increasing tripping times Page 28

29 Distribution System of a Small City No DG Installed, Radial System with Single Infeed 20 kv City network 7 MW 110 kv 40 MVA t>0.0s Utility > t>>0s t>1,5s I t>1.2s Housing area 0.5 MW t>0.9s M t>0.3s t>0.0s Industry 10 MW Protection selectivity by use of simple non-directional oc relays - Unique short-circuit direction, - Current / time grading with def. or IDMTL characteristics M Industry 3 MW Grading from load to infeed with increasing tripping times Page 29

30 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>0s t>1,5s 40 MVA I t>1.2s t> 0.6s t>0.0s t> 0.6s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.3s t>0.0s Non-directional OC-Protection Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas M Industry 3 MW Page 30 New protection concepts necessary

31 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>0s t>1,5s 40 MVA I t>1.2s t> 0.6s t>0.0s t> 0.6s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.3s t>0.0s Non-directional OC-Protection Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas M Industry 3 MW Page 31 New protection concepts necessary

32 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>0s t>1,5s 40 MVA I t>1.2s t> 0.6s t>0.0s t> 0.6s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.3s t>0.0s Non-directional OC-Protection Page 32 Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas New protection concepts necessary M Industry 3 MW Islanding of System not allowed! -No frequency control -No resynchronization

33 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>0s t>1,5s 40 MVA t>0.3s I t>1.2s t>0.0s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.9s t>0.3s t>0.0s Directional OC-Protection Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas M Industry 3 MW Page 33 New protection concepts necessary

34 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>>0s t>1,5s 40 MVA t>0.3s I t>1.2s t>0.0s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.9s t>0.3s t>0.0s Directional OC-Protection Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas M Industry 3 MW Page 34 New protection concepts necessary

35 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW 110 kv > Utility t>>0s t>0.3s 40 MVA I Decoupling device U< Q> t> 0.0s t>0.3s Biomass -plant 25 MW Housing area 0.5 MW t> 0.05s OC-Protection with directional comparison and fast U-Q decoupling M Industry 10 MW Supposed that sc currents of both infeeds are in same range No selectivity with non-directional OC protection Long fault clearing times Islanding of not-allowed areas t> 0.05s t> 0.0s M Industry 3 MW Page 35 New protection concepts necessary

36 Distribution System of a Small City Large DG Installed 20 kv City network 7 MW Utility 110 kv > t>>0s t>1,5s 40 MVA t>0.3s I t>1.2s t>0.0s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.9s t>0.3s t>0.0s Page 36 Anti-islanding logic Anti-islanding logic PMU-installation for island detection Anti-islanding protection necessary Industry 10 MW M Industry 3 MW Islanding of System not allowed! -No frequency control -No resynchronization

37 Distribution System of a Small City Large DG Installed GPS Signal 20 kv City network 7 MW Utility 110 kv > t>>0s t>1,5s 40 MVA t>0.3s I t>1.2s t>0.0s t>1.2s Biomass -plant 25 MW Housing area 0.5 MW t>0.9s M t>0.9s t>0.3s t>0.0s Page 37 Phase comparison Anti-islanding logic PMU-installation for island detection Anti-islanding protection necessary Industry 10 MW M Industry 3 MW Islanding of System not allowed! -No frequency control -No resynchronization

38 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 38

39 Underfrequency Loadshedding without and with DGs Operational Handbook entso-e P5 Policy 5: Emergency Operations Load rejection at 49,0Hz, better at 49,2Hz 50% of nominal Power shall be disconnected at 48,0 Hz. At 49,0Hz minimum 5% of total load shall be shed. Below 49,0Hz, stepwise load rejection has to be coordinated with requirements of the TSO. f <= 200mHz t AUS (inkl. CB op.-time) <= 350ms Page 39 Source: Appendix Policy 5: Emergency Operations

40 Underfrequency Loadshedding without and with DGs Actual Installations and Common Practice Transmission f< Distribution Consuming distribution system Power flow from top to down f< trips feeder CB M M M Page 40

41 Underfrequency Loadshedding without and with DGs Necessary Changes Transmission Consumer becomes Pro -sumer Changing powerflow directions f< Distribution G M M M G f< trip could trip generating distribution when generation is necessary for frequency stability of transmission Page 41

42 Underfrequency Loadshedding without and with DGs Realization in Siemens 7SJ Relays 2 Hysteresis 90 jq Basis: Angle-supervision of positive-sequence power Positive real power Feeder is consuming With measured under frequency, P/f< function trips CB φ B 180 φ A P 0 S 1 2 Hysteresis 270 ϕ (PQ pos.seq.) & P/fprotection t AUS f < xxhz Page 42

43 Underfrequency Loadshedding without and with DGs Realization in Siemens 7SJ Relays 2 Hysterese 90 jq Basis: Angle-supervision of positive-sequence power Positive real power Feeder is consuming With measured under frequency, P/f< function trips CB 180 φ A φ B S 1 P 0 Negative real power Feeder is generating Feeder helps in frequency support With measured under frequency, no trip 2 Hysterese 270 ϕ (PQ Mitsyst.) & P/f-Schutz Anregung t AUS f < xx Hz Page 43

44 Contents Transformation of the Electricity System Challenges for Protection Systems of Smart Grids Continuous Analysis of Protection Systems and Protection system audits with SIGUARD PSA Adaption of the Protection Schemes if DGs Lead to Unselectivities Which Cannot be Covered by Changes of Settings Underfrequency Loadshedding without and with DGs Summary Page 44

45 Summary Power systems with increasing DG penetration need regular protection system audits - to detect unselectivities - to help with settings adaption - to verify new calculated settings - to get a certificate that the protection system is well designed and settings are correct - to postpone CAPEX for new relaying schemes Power systems with increasing DG penetration need new protection schemes - only when no secure settings can be found - to increase the quality of power supply by reduction of SC / voltage dip duration - to develop a distribution system to a MicroGrid SmartGrids protection schemes and relays are available on market Page 45

46 Thank You for Your Attention! Prof. Dr.-Ing. Rainer Krebs Head of Protection and Control System Studies Principal Expert for Power Technologies Siemens AG, Freyeslebenstrasse Erlangen Germany Phone: Fax: Mobile: rainer.krebs@siemens.com Page 46