IEEE PES Swiss Chapter - Workshop on Power Cables

IEEE PES Swiss Chapter - Workshop on Power Cables Operational experience of high voltage power cable systems in Berlin and future planning for bulkpower lines 14.04.2010, Wilfried Fischer, 50Hertz Transmission, Berlin

Content 1. Who is 50Hertz Transmission? 2. Transmission System Operator s duties 3. New Projects for Grid Extension 4. Power cable Transmission Systems in Operation 5. Experience and Cognition 6. Power Cable Transmission Systems in Planning 7. Gas insulated Line (GIL) 8. Operational Expenditures for Power Cable Systems 2

1. 50Hertz Transmission The transmission grid 220/380 kv The grid lays right in the center of Europe with Interconnectors to Poland, Chez Republic, Danemark and Transpower provide securing reliable power supply to Europe Some facts and figures: - System Length: 9.700 km - Number of Substations: 69 - Employees: 600 - Company seat: Berlin - 6 Regional Centers - 24/7 service. 3

1.Key figures 50Hertz Transmission by December 2009 Energinet.dk Bjæverskov 400 kv DC Area: ~ 109.000 km² (~31%)* Inhabitants: ~ 18,2 Mio. (~22%)* Demand: ~ 95 TWh (~20%)* 1 KONTEK Lüdershagen Brunsbüttel Iztzehoe Wilster Stade Dollern Unterweser/ Ganderkesee Landesbergen Itzehoe/ Brokdorf Kummerfeld Wilster Mecklar Audorf HH-Süd HH-Nord Eisenach Lübeck HH-Ost Krümmel Stadorf/ Lüneburg transpower transpower Wolkramshausen Helmstedt Stahlwerk Thüringen Altenfeld Goldisthal Vieselbach Görries Stendal/West Klostermansfeld Hohenwarte II Wessin Perleberg Förderstedt Lauchstädt Rostock Wolmirstedt Taucha Schkopau Lippendorf Herlasgrün Remptendorf Redwitz Güstrow Sandtorstraße Magdeburg Großdalzig Großschwabhausen Weida Putlitz Bentwisch Siedenbrünzow Marke Pulgar Crossen Eula Markersbach Iven Lubmin Nauen Hennigsdorf Malchow Zwönitz Wustermark Brandenburg/ West Röhrsdorf Reuter a b e c d e g f Schönewalde Streumen Thyrow Freiberg/ Nord Niederwiesa Hradec Bertikow Ragow Pasewalk Neuenhagen Niederwartha Dresden/Süd Vierraden Eisenhüttenstadt f Preilack Schwarze Pumpe Jänschwalde Bärwalde Krajnik Graustein Boxberg Hagenwerder Schmölln CEPS a.s. PSE-O S.A. Mikulowa RES-infeed: ~ 25,4 TWh 1 2008 ~ 22,7 TWh thereof Wind: ~ 16,9 TWh 1 2008 ~ 16,5 TWh Pinstall. Wind: ~ 10.570 MW (~42%)* 2008 ~ 9.680 MW (~41%)* Maximum load control area: ~ 17.500 MW 2 Maximum vertical grid load: 10.330 MW Minimum vertical grid load: 3.303 MW Power plants and storages in the control area (P install. in MW) Thermal Pump storage and hydro Wind power (~42%*) Biomass, PV u.a. 1 Subtotal Total sum Grid connection (voltage level) 380/220 kv 110 kv ~ 12.860 ~ 2.400 ~ 910 ~ 7.100 ~ 500 ~ 9.660 ~ 30 ~ 1.970 ~ 16.200 ~ 19.200 ~ 35.400 * Anteil von D 1 vorläufige Angaben 2 berechnet

2. 50Hertz Transmission Security of Supply Our Core Business Keeping frequency and voltage in a narrow band Always power available Always sufficient supply of electicity Cost efficient operations of Electricity Highways 50Hertz plays a major roll as transmssion system operator for the secured supply of electricity in his control zone Based on Planning principle n-1 and lowest possible down time Two basic challenges:: - Asset Management = highways for electricity - System control= Traffic control without congestions i.e. no Brown or even Blackouts" 5

3. Current proceeding of grid extension projects Brunsbüttel Itzehoe Wilster Audorf Itzehoe/ Brokdorf Mecklar Lübeck Preilack F Förderstedt Marke Schönewalde ö Ragow Jänschwalde Graustein Klostermansfeld Schwarze Pumpe Wolkramshausen Lauchstädt Taucha Bärwalde Schkopau Streumen Boxberg Lauchst ädt Lippendorf Pulgar Großdalzig Eula Schmölln Niederwartha Hagenwerder Erfurt/Nord Dresden/Süd Röhrs- Großschwabhausen dorf Vieselbach Weida Stahlwerk 4 Thüringen Stahlwerk üringen Th Crossen Hohenwarte II Zwönitz Niederwiesa Altenfeld Remptendorf Herlasgrün Markersbach ČEPS a.s. Kummerfeld HH-Nord Stade Wilster Dollern HH-Ost - Unterweser/ Ganderkesee Landesbergen HH-Süd TPS TPS Stadorf / Lüneberg Eisenach Krümmel Helmstedt Perleberg 400 kv DC KONTEK Rostock Putlitz Wolmirstedt Sandtorstraße Magdeburg Lüdershagen Bentwisch Siedenbrünzow Nauen Hennigsdorf Malchow Reuter a b d e Wuster - c g e mark f Brandenburg/ West Thyrow Vieselbach Altenfeld Goldisthal Görries 1 Güstrow Redwitz Energinet.dk Bjæverskov 3 Iven Hradec Lubmin Pasewalk Bertikow 2 Neuenhagen Eisenhüttenstadt Krajnik PSE-O.S.A. 5 Mikulowa 1 2 3 4 5 Northern Line (TEN-E-Project) - Mecklenburg-Western Pomerania: Approval of Plan done 09/09, - start of construction 09/09, comissioning planned for 12/10 - Schleswig-Holstein: Approval of Plan under way Uckermark Line (TEN-E-Project) - Approval of Plan under way - Severe public opposition claiming to cable 25 km North Ring Berlin - Regional Planning Procedure projected Southwest Coupling Line (TEN-E-Project) - Lauchstädt-Vieselbach: commissioned 12/08 - Vieselbach-Altenfeld: Regional Planning Procedure finished, Approval of Plan under way - Altenfeld-Redwitz: Regional Planning Procedure started 1/10 (massive lack of acceptance, pilot project of cable section) 3rd Interconnector to Poland - Regional Planning Procedure projected

Operational Experience of XLPE Power cables 4. In Operation XLPE-Cable Supply Systems in Berlin 380 kv Diagonal 220 kv South in feed Oilfilled Cable systems in Berlin and at the coast of the Baltic Sea 380 kv Diagonal 400 kv Buried HVDC oil filled Cable 5.Experience and Cognition 6. In Planning 380 kv AC XLPE Cables Transmission systems for Thuringia 150 kv AC XLPE Seacable for Windpark Baltic 1

4. 380 and 220-kV-Power Cable Systems in Berlin Lubmin 380-kV-Diagonal Wolmirstedt 380-kV-Cables Systems Teufelsbruch Malchow 380-kV-Overhead Line 220-kV-Overhead Line 110-kV-Grid Reuter Reuter 1 Reuter 2 Malchow Friedrichshain Charlottenburg Mitte Friedrichshain Marzahn Neuenhagen Substations Mitte 1 Mitte 2 Wuhlheide Wuhlheide 220-kV- sectional cabling on a length of 1,8 km Berlin Thyrow Preilack

4. 380-kV-Diagonal Berlin VEAG Neuenhagen VEAG Wolmirstedt Teufelsbruch Reuter Mitte Friedrichshain Marzahn TB RE 1994 1978 1998 2000 1997 MI FRH MZA IPH Havel Schloßpark Spree Length in km 180 7,6 2,6 8,1 6,3 5,2 29 overhead line oil-filled cable overhead line oil-filled cable XLPE-cable XLPE-cable overhead line Capacity 1800 MVA 1100 MVA Water cooled in pipe Water cooled in pipe air cooled in tunnel

4. Parameter for aging tests of XLPE cables of six different suppliers in 1993-1997 two one year test series Cable length 120 mts Heat/cooling cycle 16 h / 32 h max. temperature of conductor 90 C (+ 5 K, - 0 K) Test Voltage at 50Hz 400 kv *) Test duration 1 year (twice) Switching impulse voltage (250/2500 µs) 950 kv (5 pos, 5 neg) Lighning impuls voltage (1,2 / 50 µs) 1175 kv (10 pos,10 neg) *) with continuous monitoring and messuring of partial discharge at all joints and terminals Test Field at CESI Laboratory Milan

4. View into the Berlin Tunnel 11,5 km x 3 phases x 2 syst. = 69 km single core cable (3 suppliers, 4 sections) 15 x 3 x 2 = 90 partial lengths 13 x 3 x 2 = 78 Joints 4 x 3 x 2 = 24 Terminals

4. HVDC Link Kontec Danmark-Germany 400 KV oilfilled cable in flat design, length 13 km, land cable Cable Joint

5. 400 kv Cable failure Overview 380-kV-Overhead line 380-kV-Oilfilled Cable 380-kV-XLPE Cable installed in tunnel 21,4 System-km 31,4 System-km 23,8 System-km 11,9 km 05.12.2009 50Hz Transmission Substation Neuenhagen 50HzTransmission Wolmirstedt Reuter Mitte Friedrichshain Marzahn TB RE MI FRH 1994 1978 1998 2000 1998 MZA IPH Overhead line 1,1 km (Berliner Gebiet) (1) Oilcable 7,6 km (2) (3) (1) Tunnel Teufelsseekanal: 0,32 km (2) Tunnel Havelquerung: 0,52 km (3) Tunnel Schloßpark: 1,10 km (4) Tunnel Spree: 0,27 km Overhead line 2,6 km (4) Oilcable 8,1 km 6,3 km Tunnel 5,2 km Tunnel XPLE Cable 6,5 km XPLE CableOverhead line 5,4 km 7,0 km (Berliner Gebiet)

5. 400 kv Cable Failure Event Data: - Time: 05.12.2009; 19:22 Uhr - Voltage level: 400 kv - Security of supply: no reduction due to redundancy - Cable System: line number 921, Friedrichshain-Marzahn - Type of fault: Phase 2 to earth - Short circuit current 36 ka - Fault duration: 70 ms - Location: Cable terminal phase 2 in SF6 compartment, contaminating the complete switchgear hall - Estimated costs up to 1 Mio six digits - Estimated time of non availabilty appr 8 months

5. 400-kV-Failure on System 921, L2, EV 2

5. 220 kv Cable failures on Transmission system Lubmin 1.1.2008 1.2.2008 380-kV-Diagonal Wolmirstedt 380-kV-Kabel Teufelsbruch Malchow 380-kV-Freileitung 220-kV-Freileitung 110-kV-Netz Reuter Reuter 1 Reuter 2 Malchow Friedrichshain Charlottenburg Mitte Friedrichshain Marzahn Neuenhagen Umspannwerk Mitte 1 Mitte 2 Wuhlheide Wuhlheide Partial cabling 1,8km Length Berlin Thyrow Preilack Upon request of the financial investor Adlershofer Projekt GmbH and on request of the Senatsverwaltung für Stadtentwicklung a partial cabling section was initiated and paid.

5. Failure at cable terminal of 220-kV-Transmission Line Marzahn Wuhlheide Thyrow 291 / 302, Mast 84 Transition Tower From Overhead line to buried cable system Commissioning of the XLPE Cable Transmission System on 19.10.2007

5. Two Exploded Cable terminals First cable failure on 1.1.2008 failure at terminal phase L3 of line 302 (supposed : poor workmanship ), repair until 29.1.2008 Second cable failure on 1.2.2008 failure at terminal phase L2 of line 291 including contamination and damages of adjacent properties (unclear: design mistake?) Loss of confidence twice! We in technology and stakeholders in us Decommissioning of both systems on 1.2.2008 Start of special operational conditions in 110-kV-grid

5. Solution Start of intensive investigations of several experts Clarification of possible causes for failures (design or manufacture or poor workmanship or external impuls surges?) Provision of a cable terminal of a different supplier exchange of all terminals Relocation and enhousing of the terminals Prerequistes for recommissioning Successful systemtest Agreement with stakeholders concerning compensation of damages and limited liabilty Revised permission for different arrangement transistion tower

5. Relocation of the cable terminal Placement of the terminals and the lightning arrestors New terminal building Front view Any fragments of an exploded terminal should be captured within the terminal building Recommissiong of line 302 on 18.6.2009 Recommissing of line 291 on 7.9.2009 End of special operational conditions in 110-kV-grid

5. The bath tube of failure rate 220 kv Adlershof Teething problems? 380kV Marzahn Aging of material? Malfunction? Failure rate-outagenon availability? Start of life End of life Time

5. Availabilty of XLPE power cables transmission systems

5. Monitoring of 10 Year Periode 2001-2010 Voltage Level Down Time in days Year of occurence Number of systems installed Mean Down Time per system in days 380 KV 50 2002 4 12,5 380 kv 35 2004 4 8,75 380 kv 40 2006 4 10 220 kv 699 2008 6 116,5 220/380 kv 441 2009 6 73,5 380 kv 600* 2010 6 100 Mean Down Time per System for 10 years 321,25 *expected Mean Down Time per system and year in% 8,80 % Scheduled unavailability for maintenance annually 5 days per system i.e. 1,37 %

6. Power Cable Systems in Planning Southwest Coupling Line- Power Bridge of Thuringia Feasibilty Study on power cable section in the natural resort Thuringia Forest at the crestline Rennsteig Scope of the study: -Dimensions - Investment Costs -Logistics -Outdoor activities -Construction time More under http://www.forum-netzintegration.de/uploads/media/sassnick_vet_170309_duh.pdf

6. The challenge: crossing the Thuringia Forest: Installation of a powerful coupling line for 3600 Amp per system i.e. 2500 MVA (n-1) secured from Halle/Saale to Schweinfurt Sachsen-Anhalt UW Lauchstädt Rennsteig UW Vieselbach Thüringen Existing UW Altenfeld UW Schweinfurt i Naturpark Existing Planned 380-kV-Route UW Redwitz Bayern Southwest coupling line, Power Bridge of Thuringia

6. Feasibilty study for 3600 A per System Rennsteig UW Grafenrheinfeld Sachsen-Anhalt UW Lauchstädt UW Vieselbach UW Altenfeld UW Redwitz Thüringen Bestehende Leitung The 380-kV-line crosses the monument crestline Rennsteig and the natural resort Thuringia Forest. Stakeholders require non-visible overheadline or at least a transmission solution with lowest possible visibility Thecrossingof thehikingtrail Rennsteig seems possible at two different locations i Naturpark Bestehende Leitung Geplante 380-kV-Leitungstrasse Bayern Transmission solution is required which satisfied the protection of the environment, the expections of the stakeholders in tourism and the forestrial authority

6. From Single core cable via pilot cable system to transmission system System 1=Pilotkabelanlage System 2 System 1 System 4 System 3 System 2 System 1

6. Technical core data of the single core cable Technical data of the single core cable acc. To feasibilty study Conductor material: Copper Cross section : 2500 qmm Rated Voltage: 230/380 Kilovolt Rated current 1.800 Ampere Outer diameter : 15 centimeter Weight: 40 tons /kilometer Insulation : Crosslinked Polyethylen (XLPE) Maximum permissible temperatureof insulation : 90 (Otherwise irreversible desolution of crosslinked molecure chains with the loss of insulating capability) Losses per three phase system at 1800 Amp : 120 kw/km Heat value of 60 W/ sqm Heat quantity can warm up 100 hecto liter in one hour by 10 C

6. Transition Unit Overheadline / Cable Systems Transition unit for two transmission systems ( area appr 70 mts x 35 mts Übergangsstelle Freileitung auf Kabel für eine 2-systemige Übertragungsleitung (ca. 70 m x 35 m)

6. Enhousing of the transition unit as done in Berlin appears compulsary and advisory für Thuringia as well

6. At a glance the complete transmission system 4 x 4 x Overheadline Transistion unit Buried Cables system with 2 crossbonding bunkers Transistion unit Overheadline

6. Cost Estimate of Partial Cabling Budget Costs: Variant 1 Variant 2 Route length ca. 1.800 mts ca. 800 mts Pilotphase 1 System Double cable system inlc. Trenching and preparation of second double system 18.7 Mio. 8 Mio. Extension by second system Two Double Cables Systems in total 30 Mio. 12.25 Mio. Overhead Line 2 Systems 2,6 Mio. 1,15 Mio.

6. Seacable connection of Offshore-Windparks Baltic 1 The Windpark Baltic 1 is situated appr. 15 km north of the peninsula Fischland-Darß-Zingst. 50Hz Offshore is responsible for the grid connection from the windpark to nearest substation Bentwisch / Rostock. According to the current planning Baltic 1 will be the first Windpark in the German Baltic Sea. 21 Wind mills will in feed 52,5 MW in total. Developer and Owner of the Offshore windpark is EnBW Ostsee Offshore GmbH.

6. OWP Baltic 1 The Seacable Construction Kupfer-Leiter Feldsteuerung aus halbleitendem Polyethylen (PE) Isolation Dichtungsband Bleimantel Füllkörper PE Bitumenhaltiger Außenmantel Polypropylen Garn Galvanisierte Stahldrähte Integriertes Glasfaser- Datenkabel

6. Offsore Wind Park WP Baltic 1 Submarine Cable The seacable consists of three single core copper conducutors with internal and external conductive layer and cross linked polyethylen, XPLE The integrated fibre optics transmit the relevant control, alarm and protection data. The complete cable is steel armoured against mechanical damages, of course corrission protected. Do not forget the joints! Rated Voltage:150 kv AC Max.Voltage: 170 kv Rated current 1000 Amp Capacity 260 MVA Outer diameter: 23,5 cm Weight in air: 105 kg/m Cross section: 1.200 mm 2 per phase Material of conductor: Copper Insulation: Cross linked Polyethylen (XLPE)

7. State of the Art Transmission Technology Overhead Line and GIL in Tunnel Easy construction at site : small dimensions Short periode of civil work Inherent protection against external impact

7. Buried GIL at Frankfurt Airport, appr 1 km system length currently under commissioning All pictures by courtesty of Siemens Energy

7. Dimension of buried GIL 380 kv in a Trench with Tanssmission capacity up to 2 x 3000 MVA

7. GIL System Features Fits in Overhead line System e.g. Automatic reclosure functionality!! No additional secondary and auxiliary systems Reuse of Components of SF6 Switchgear which are field proven for decades Low resistive losses Negligible No-Load losses High ampacity Prepared for future higher voltage operation Low cooling expenditures (if any) No reactive compensation (<100km) No ageing of insulating gas Extreme low external electromagnetic fields High safety (no fire hazard)

8. Operational Expenditures OPEX for sectional Power cable system Transmission system Transmission element Cable system Cable =Transmission element + property negotiation + access road + surveillance + inspection + route management = min. 2 cable systems + civil works + laying + commissioning + transition unit incl cts,vts, arresstors + protection/ remote control units + commissioning of the line =3 cables + joints + sealing ends + engineering (incl.thermal calculation) = a maintenance free product

8. Costs for maintenance and service for a sectional cable transmission system (OPEX) Calculated annual opex for maintenance and service incl. Spare units for equivalent availability 15.000 /km Cable route: -Frequent inspection tours for visible changes (surveillance) -Clearing of route by grass keeping and dismantling of small trees and bushes - Clearing of Access roads in winter time - Cable joints and cross bonding: -inspection and visible checks, test of cable shielding -Cable terminal and transistion unit - inspection and visible checks -Maintenance and checks on cts, vts, arrestors, cable terminals, auxiliary power supply Ac / DC, and building -Integrated Checks of protection and control subsystems

More information upon request by 50Hertz Transmission GmbH Eichenstraße 3A, D-12435 Berlin-Treptow Tel. +49 30 5150 3108, Fax +49305150 3110 Mobil +49 172 3 20 60 49 Wilfried.Fischer @50Hertz- Transmission.net www.50hertztransmission.net