Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System October 24-26, 2012 THE HIGH-VOLTAGE NETWORK OF CERN TODAY François Duval Head of the Electrical Engineering Group EN Department CERN

Outline  The High Voltage grid  Sources of Energy at CERN  Normal operation  Degraded Operating Modes  Critical Points  Present Power Consumption  Estimates at the HL-LHC Horizon  Methodology  Power Requirements October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 2 The Status of the CERN Distribution Network Present Consumption and Future Estimates Part 1 Part 2

The CERN Accelerator Complex October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 3

The layout October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 4

The Layout of the HV Grid October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 5

The Present HV Network October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 6 Meyrin & the PS ’s Prévessin & the SPS 1970’s LHC 1980’s

The Present HV Network October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 7 Main source EDF > 300 MW Alternative source SIG/ALPIQ ≤ 60 MW

The Different Voltage Levels October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval kVFrom the French grid through an interconnection substation “Bois- Tollot” located 300 m from CERN 400 kV. An OHL is connected to the busbar (no incomer). From this busbar, 5 CBs feed 5 power transformers (3 400/18 kV and 2 400/66 kV) 66 kVFeeds 5 LHC Points & the Prevessin Distribution Substation (BE9) from a double busbar substation with no redundancy. 20 kVSafety feeders from public distribution at LHC points 18 kVVarious 18 kV distribution system (loops, antenna distribution with redundancy, direct feeders to big loads) 6.3 kVLocal system from Diesel generators 3.3 kVLocal 3.3 kV system for big motors (compressors) and Diesel generators

The Sources of Energy at CERN October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 9

The Sources  EDF/RTE  400MVA  SIG/Alpiq  60MVA  Emergency source  The evolution  Sharing between the two sources until 1995,  For cost reasons and the limited available power the relegation of the SIG source to a back-up source to be used only in case of outage of the EDF source or during maintenance October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 10

Quality  The quality of the energy delivered at CERN is affected by external and internal causes:  Internal  High level of Harmonics from power converters  Voltage drops from short circuits  Lack of selectivity  External  Harmonics 2 from Power transformers energizing through CERN filters October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 11

Quality  Voltage drops due to faults on the grid (mainly lightning) This topic was specified for the LHC project (EDMS Main parameters of the LHC 400/230 V distribution system) October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 12

Quality October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 13

Normal Operation October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 14 The 66 kV network of the LHC Sites and the General Services for the the LHC, the SPS and its North Experimental Area ▶ EHT4 and EHT5 110MVA 400/66 kV, identical and operate in parallel ▶ EHT7 70 MVA 66/18 kV feeds the General Services of the Prevessin Site, the SPS and the LHC ▶ The LHC is fed, without any redundancy, from LHC points  1 EHT MVA 66/18 kV  2, 4, 6 & 8, EHT102/ MVA 66/18 kV The 66 kV network of the LHC Sites and the General Services for the the LHC, the SPS and its North Experimental Area ▶ EHT4 and EHT5 110MVA 400/66 kV, identical and operate in parallel ▶ EHT7 70 MVA 66/18 kV feeds the General Services of the Prevessin Site, the SPS and the LHC ▶ The LHC is fed, without any redundancy, from LHC points  1 EHT MVA 66/18 kV  2, 4, 6 & 8, EHT102/ MVA 66/18 kV

October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 15 Normal Operation The 18 kV pulsed network of the magnet system of the SPS and its North Experimental Area ▶ From the BE substation which is made of 3 busbars, each one fed from a 400/18 kV 90 MVA transformer, each busbar is connected to an SVC system of 120/150 MVAR ▶ 2 busbars out of 3 are necessary to operate the pulsed network ▶ The high capacitive current generated by the SVC is higher than the performance of the 18 kV CB, therefore the busbar protection is supported by the 18 kV incomers with the risk of high capacitive currents to be cut. The 18 kV pulsed network of the magnet system of the SPS and its North Experimental Area ▶ From the BE substation which is made of 3 busbars, each one fed from a 400/18 kV 90 MVA transformer, each busbar is connected to an SVC system of 120/150 MVAR ▶ 2 busbars out of 3 are necessary to operate the pulsed network ▶ The high capacitive current generated by the SVC is higher than the performance of the 18 kV CB, therefore the busbar protection is supported by the 18 kV incomers with the risk of high capacitive currents to be cut.

October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 16 Normal Operation The Meyrin Site ▶ All the Meyrin site is fed from the main substation in LHC Point 1 through the MP5 link (60 MVA) ▶ There is no separation between General Services network and the facilities (accelerators, experimental areas, computer centre, etc.) The Meyrin Site ▶ All the Meyrin site is fed from the main substation in LHC Point 1 through the MP5 link (60 MVA) ▶ There is no separation between General Services network and the facilities (accelerators, experimental areas, computer centre, etc.)

October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 17 Normal Operation Autotransfert ▶ There is an automatic reconfiguration of the general services network called AUTOTRANSFERT managed by PLCs. ▶ It is based on the presence of voltage on the following busbars: BE9, ME9 and SEM12 Autotransfert ▶ There is an automatic reconfiguration of the general services network called AUTOTRANSFERT managed by PLCs. ▶ It is based on the presence of voltage on the following busbars: BE9, ME9 and SEM12

Degraded Operation  With the present consumption (LHC at 4 TeV) the network is able to cope with the outage of one major component:  a transformer (400/66 kV or 66/18 kV) or  an 18 kV site inter-site link.  In the event of such a failure, the 18 kV network can be reconfigured to support accelerator operations at nominal power.  See EDMS document no October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 18

Degraded Operation  Outage of EHT7  The load is taken by EHT3 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 19

Degraded Operation  Outage of EHT102 in LHC Poin t 1  The load is taken via inter-site link MP6 on EHT7 and from SIG October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 20

Degraded Operation  Outage of EHT4 or EHT5  The load is taken by EHT3 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 21

Degraded Operation  Outage of EHT102 in any of the LHC Points 2,4,6 or 8  No redundancy ! (only spares: one week to repair) October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 22

Degraded Operation  Outage of inter-site link MP5  The load is taken via inter-site link MP6 and EHT7 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 23

Degraded Operation  Outage of inter-site link MP7  The load is taken via inter-site link MP6 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 24

Critical Points  The network has a number of weak points that affect  operational capability,  availability,  maintainability,  economy,  reliability and  safety.  There are components  the failure of which would have a long-term impact on accelerator operations and/or  have operational limitations linked to network dimensioning and maintenance. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 25

Operational Capability1  The Meyrin site is fed only by one substation (ME9 JURA). This substation has two sources:  SIG/Alpiq (Switzerland) through ME10  EDF (France) through LHC Point 1  Operation with a single 400/66 kV 110 MVA transformer is only possible if transformer EHT3 do not operate on the SPS pulsed network.  The network does not allow reconfigurations to supply loads which are critical for the operation of the LHC October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 26

Operational Capability2  The 18 kV substation (ME43) for the computer centre in building 513 is part of the 18 kV ring that supplies the PS Booster and ISOLDE. This ring is operating near its rated capacity.  The inter-site links (MP6 & MP7, today limited to 30 MVA) do not allow all degraded modes at full power.  The mixing in some substations (BE9 and ME59) of interconnection and distribution functions limits the operation capability. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 27

Availability  The diversity of technologies used for the switchgears and protection relays,  The complexity of the HV grid,  The numerous possibilities for reconfiguration and  The need for very rapid fault-clearing make the task of implementing protection and efficient selectivity difficult.  No separation between the General Services Network and the facilities on the Meyrin site (accelerators, experimental areas, computer centre, etc.) October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 28

Maintainability  The yearly tests of the AUTOTRANSFERT system, cannot be done without power cuts on the Meyrin site  During the maintenance of the 400 kV substation, CERN is limited to 60 MVA because of the SIG source; this leads to continuous delays of the maintenance operations. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 29

Reliability related to ageing  The power cables of SPS are close to their end of life. Pulsed and not filtered currents overstress the junctions and the failure rate is sharply increasing.  The 400 kV busbars and auxiliary connections require replacement October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 30

Redundancy  A single OHL connects the 400 kV source to CERN  The 66 kV distribution for the LHC is made of 5 antennas  The power demand of the CERN Control Centre has grown and eroded the redundancy and maintainability. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 31

Safety  Most of the equipment (cubicles and cables) of Meyrin, Prevessin and SPS date from the 60’s or 70’s; they are no longer in compliance with the currently applicable standards for safety and operational reliability.  The 400 kV substation at BE lacks protection (such as firewalls) against the spread of a possible fire from one of the five transformers to adjacent installations.  The Diesel safety network of the SPS cannot meet anymore the needs of the Prévessin site October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 32

Economy  With the present power consumption, the failure of some of the network components can be tolerated. This involves network reconfigurations which require in some cases the connection to the SIG (Switzerland) source where energy is very expensive. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 33

Outline  The High Voltage grid  Sources of Energy at CERN  Normal operation  Degraded Operating Modes  Critical Points  Present Power Consumption  Estimates at the HL-LHC Horizon  Methodology  Power Requirements October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 34 The Status of the CERN Distribution Network Present Consumption and Future Estimates Part 1 Part 2

Present Power Consumption  Present power consumption was measured in July 2012;  The power values are the average of instantaneous power over 10 minutes  A particular attention is required on the difference between measured power flowing through a bus-bar and the sum of the power measured downstream October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 35

Present Power Consumption Measured in July 2012 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 36

October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 37

Estimates for the Future The inventory 1. Future upgrades/consolidations :  LHC operation at 7 TeV per beam  HL-LHC project  Upgrades of the LHC experiments  Planned upgrades and consolidation of the accelerators  Planned increase of the capacity of the Computer Centre. 2. The shutdown of CNGS, DIRAC and LINAC2 3. Approved future or ongoing projects both in Prévessin and Meyrin:  CCC consolidation,  New Building 107,  Consolidation Building 867 and  Additional needs of the various laboratories and test areas. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 38

Estimates for the Future Methodology  The estimated active and reactive power figures set out in the tables of this document are based exclusively on the power load forecasts provided by the users and do not take rectification in account.  The drop in consumption during long shutdowns are not considered.  Power forecasts on 400/66 et 66/18 kV transformers have been done considering only the existing filters and TCRs. Also, any filter failure will impact the operation of the accelerators. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval - 39

Estimates for the Future LHC at 7 TeV October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval %

Estimates for the Future HL-LHC October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System François Duval %