Superconducting Cable Systems for Urban Areas AmpaCity Project - Germany

Transcription

1 Superconducting Cable Systems for Urban Areas AmpaCity Project - Germany Frank Schmidt Frank.Schmidt@Nexans.com 2016 IEEE PES General Meeting

2 Agenda Project overview Motivation for HTS cables Components of the system Operation experience Conclusions

3 AmpaCity Installation in Essen, Germany Technical specification - 1 km distance between substations - 10 kv system voltage ka operating current () Substation Herkules Cable Joint Substation Dellbrügge System in continuous operation since March 10 th, 2014 Luftbild: "Darstellung aus HK Luftbilder / Karten Lizenz Nr. 197 / 2012 mit Genehmigung vom Amt für Geoinformation, Vermessung und Kataster der Stadt Essen vom "

4 Advantages of HTS Cable Technology Increased power density through application of HTS cables Avoiding higher voltage levels for power transmission and distribution Negligible thermal impact on the environment No drying out of soil, no thermal backfill required No maximum laying depth, no bottlenecks at cable crossings No outer magnetic field during normal operation Reduced space for substations and for cable installation Simplified cable installation, less civil works Space-savings in urban areas Increased operating safety due to fault current limitation

5 Motivation for AmpaCity Project Substation in suburban area HV Substation in suburban area HV Conventional HV cable system MV HV Superconducting MV cable system MV Substation in Substation in MV city center city center

6 AmpaCity One Line Diagram Initial Substation Dellbrügge Situation Substation Herkules 110-kV-cabel 10 kv 110-kV-cabel 10 kv 110 kv

7 AmpaCity One Line Diagram Current Substation Dellbrügge Situation Substation Herkules 10-kV-HTS-cable 110-kV-cabel SSB 10 kv Reduction of one transformer 110/10 kv 10 kv 110 kv

8 2,6 km 3,1 km 2,7 km 2,6 km 4,6 km 3,0 km Grid Layout with MV HTS Cables 110 kv OHL 110 kv UGC 10 kv UGC 110 kv busbar 10 kv busbar Bus tie (open) C 4,3 km A D 6,2 km 5,0 km 2,2 km B E Future grid structure has been designed based on Conventional 110 kv cables Superconducting 10 kv cables F Perquisites: same redundancy (n-1) Economic viability compared G 4,7 km H 3,6 km I 3,2 km J

9 2,7 km 2,7 km 2,6 km 2,6 km 8,4 km 3,0 km 3,0 km 4,6 km Grid Layout with MV HTS Cables 110 kv OHL 110 kv UGC 10 kv UGC 110 kv busbar 10 kv busbar Bus tie (open) C A 6,2 km B 5,0 km E D Dispensable devices for new grid concept 12.1 km of 110 kv cable systems 12 x 110 kv cable switchgear 5 x, 110/10 kv transformers 5 x 110 kv transformer switchgear 5 x 10 kv transformer switchgear F Additionally required devices for new grid concept 23.4 km of 10 kv HTS cable system 16 x 10 kv cable switchgear 3 x 10 kv bus ties G 4,7 km H 6,8 km J 3,6 km I 3,2 km

10 Concentric Cable Design for MV Applications Inner LN 2 Cooling Phase 1 Phase 2 Phase 3 Screen Former Dielectric Outer LN 2 Cooling Cable Cryostat

11 Superconducting fault current limiter Parameter Nominal power Nominal voltage Operating current Rated lightning impulse withstand voltage Rated AC withstand voltage Prospective unlimited peak current Prospective unlimited symmetric current Limited peak current Limited symmetric current Limitation time Recovery time Value 10 kv 2.3 ka 75 kv 28 kv 50 ka 20 ka < 13 ka < 5 ka 100 ms < 10 min

12 Cooling System Design > 4 kw cold power at 67 K > Subcooled pressurized nitrogen > Forced flow in closed circuit > High availability and reliability SFCL LN 2 storage tank vacuum pump sub cooler circulation pump pressure build-up HTS cable

13 Civil engineering an essential component for the realization of the project > Reduction of the expense and the negative impacts Less amount of space for the HTS system Division into construction phases Laying of empty conduits for cable pulling

14 Installation and pre-commissioning > Cable system Delivery > Cable system Assembly of the U-Bend > Cable system Pulling > Cable system Connection joint and joint pit

15 Installation and pre-commissioning > Superconducting fault currrent limiter Installation > Refrigeration system Delivery, installation of the LN-tank > Cable Refrigeration system system Pulling Mounting > On-site cable test Voltage test, tan d, PD

16 Commissioning Test Standard cable test with VLF equipment PD measurement (20 0,1 Hz) Dielectric loss factor measurement (10 kv, 15 kv, 20 0,1 Hz) AC withstand voltage test (30 0,1 Hz for 1 h)

17 Operation Experience Lessons Learned > Balancing earth capacitance Compensation of unsymmetrical cable earth capacitances by installing capacitors > Cooling system optimization Modification of vacuum pumps after freezing of humidity and other smaller optimizations > Control system optimization Increase of response time after automatic reclosing for continuous operation after HV faults System operation since commissioning without problems, only few minor optimizations of cooling and control system during operation

18 Current in A Voltage in kv Voltage and Current

19 Temperature in K Temperatures Temperature Substation Dellbrügge OutletTemperature Substation Herkules Inlet Temperature Substation Herkules

20 Pressure in bar Pressures Inlet Pressure Substation Herkules Pressure Substation Dellbrügge Outlet Pressure Substation Herkules 5.0

21 Mass Flow in g/s Liquid Nitrogen Mass Flow

22 Losses in W System Losses at Operating Temperature

23 Level in % Liquid Nitrogen Storage Tank Level

24 Short Circuit Testing in Live Grid Operation Two short circuit tests, three phase short circuit current without earth contact One short circuit test, two phase short circuit current without earth contact One ground fault test, single phase with 5 minutes duration (isolated neutral) One short circuit test, single phase with neutral impedance (< 2 ka)

25 Current Strom in in ka ka 3-Phase Short Circuit Current 10 9 i_l1 8 7 i_l2 6 5 i_l Time Zeit in in ms ms

26 Current in ka Strom in ka 2-Phase Short Circuit Current 9 8 i_l1 7 i_l2 6 i_l Time Zeit in ms

27 Current Strom in in ka ka 1-Phase Short Circuit Current 2,4 2,0 1,6 1,2 0,8 0,4 0, ,4-0,8-1,2-1,6-2,0 i_l1 i_l2 i_l3-2,4 Time Zeit in in ms ms

28 Short Circuit Testing Results All tests conducted gave expected results Protokollierung von Strom und Spannung Betriebsparameter des Strombegrenzers AmpaCity system operates exactly as designed, including fault current limitation Tests prove maturity of technology under real grid Betriebsbereitschaft nach kurzer Erholzeit operating conditions Temperaturverlauf Strombegrenzer während wieder einsatzbereit Kurzschluss

29 HTS is the technology for future urban grids Feasibility study with very positive results; amongst others: HV/MV stations in conurbations can be dropped by using HTS systems smarter grid structures and less requirement of space by extension of the grid with HTS cables Testing the superconducting cable in practical use at RWE The field test in Essen proved the maturity of HTS system under real grid conditions Superconducting components will become more competitive to conventional technology increasing capacity for the production of superconducting tapes scaling effects for cable system production reduced development and engineering optimized cable laying

30 Questions are Welcome Frank Schmidt Nexans Deutschland GmbH Kabelkamp Hannover