the high-voltage network of CERN ToMORROW François Duval Head of the Electrical Engineering Group EN Department CERN

The Project for the Consolidation and Upgrade of the CERN Electrical Distribution System Outline Objectives Principles Evolution of the Power Consumption CERN network evolution steps (long shutdowns) Consolidation & Upgrade Project Organisation Project Schedule October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Objectives Improve safety, reliability and availability Simplify and standardise the topology of the 18 kV networks Upgrade the 3.3 kV safety power main serving the SPS, the North Area (NA) and the Prévessin site Upgrade and re-dimension the transmission network so as to provide the power CERN will require in the coming years October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 1. Separate the loads by type The networks used for general services, safety, stable & pulsed/machine have to be clearly separated and be operated separately. Only general services networks are secured by AUTOTRANSFERT. These different networks may be interconnected during periods of shutdowns or major failures. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 2. Create a transmission network Upstream from the 18 kV distribution networks, a primary network called “transmission” must ensure exchanges and deliveries of power between sites. This transmission network will be dimensioned at 60 MVA in accordance with the needs and the capacity of our main transformers (70 MVA) Transmission and distribution networks have to be separated. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 3. Implement redundancy 1 of 3 Inter-site links The transport network architecture will make any reconfiguration possible after the failure of one of the major component of this network. Very high-voltage transformers All Very High Voltage transformers 400/66 kV et 400/18 kV distribution must be coupled with a redundant solution able to carry the load in case of failure. Sources of power for the transmission substations The main substations will have at least 3 independent power sources in order to face any major failure by reconfiguring the network. The maintenance and yearly tests will be facilitated as well. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 3. Implement redundancy 2 of 3 400 kV power source The 400 kV feeder is the only source capable of meeting CERN’s entire power requirements. To facilitate maintenance of the BE substation and provide a backup way of supplying power from the French RTE grid, CERN requires an alternative feeder from the Bois-Tollot substation. Backup supply for AUTOTRANSFERT At least two of the transmission grid substations will have to have an 18 kV supply feeder from SIG, so to provide one level of redundancy and improve the availability for AUTOTRANSFERT. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 3. Implement redundancy 3 of 3 Ring-topology supply for 18 kV substations The 18 kV secondary distribution networks are supplied using a closed-loop topology. The loops must not be dependent on a single substation. The loops will have access to an alternative source in case of failure. The supply of the computer centre The supply of the sensitive electrical loads of the computer centre in Building 513 needs to be made/kept independent of the loads of the PS complex, and also requires a third source of power October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principles 4. Upgrade New equipment Ageing Components : Selectivity The present protection system made of heterogeneous equipment is in some cases only able of chronometric selectivity which is not compatible with the many steps of CERN network. An upgrade is necessary using more widely differential protections for busbars, transformers and interconnects. New equipment New equipment will be dimensioned to have a 50% margin in capacity. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Evolution of the demand Two phases: LHC operation at 7 TeV after the first long shutdown (LS1, end-2014), operation of HL-LHC after the second long shutdown (LS2, end-2018). Upgrades are mandatory during LS1 in order : to prepare for LHC operations at 7 TeV from 2014 onwards, and to be able to carry-out consolidation and upgrades between LS1 and LS2 without affecting operation. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

The case of the 400/66 kV transformer set after LS2 The cost of transferring 30 MVA to the Swiss grid for 18 months (the length of time that would be needed to manufacture a new 400/66 kV transformer) has been calculated; it is comparable to the price of a spare transformer. For operation during the HL-LHC era, the estimated total load on the 66 kV network will exceed the combined nominal power of the two transformers. The need for an additional 400/66 kV supply will then become imperative. All of the 66 kV LHC substations and BE9 will be able to handle the power increase. LHC1 will reach 90% of its capacity but an additional margin will be given by upgrade projects (additional source to Meyrin site) October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

The cryogenic nature of the LHC impacts consolidation and upgrades The world largest cryogenic system is cooling down the LHC. The system has very long time constants making interruption of power impossible. The recooling of the LHC to nominal operating temperature (1.9 K for most of its components) takes 2 months and is costly. In order to avoid this, the runs of the LHC are organized to be very long (3 to 4 years) separated by long shut downs (1,5-2 years). During the run, technical stops (1 week) and Christmas break (2 months) allow light maintenance operations. During these technical stops, the cryo system remains in operation and any upgrade or consolidation affecting or risking to affect its operation is prohibited. Therefore, all commissioning and operations requiring power cuts of major projects can only be carried-out during long shut downs. During these periods, infrastructure, allowing alternative network configurations must be put in place, to permit evolution during the runs. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principal components of the upgrade and extension plan Upgrade of the 400 kV and 66 kV systems, Items: overhaul of the 66 kV protection systems; a second feeder to the CERN 400 kV system; construction of a 66 kV substation on the Meyrin site, with its own power factor correction system. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Upgrade of the 400 kV and 66 kV systems The configuration today October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Upgrade of the 400 kV and 66 kV systems The configuration for LS2 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principal components of the upgrade and extension plan Creation of a 60 MVA, 18 kV transmission network linking the principal substations in a point-to-point topology removal of load circuits from the substations that will form the transmission network (to be transferred to the distribution substations); construction of a new site-to-site interconnect between Prévessin and Meyrin, so as to provide an alternative path for supplying the West Area from the EHT3 transformer. Upgrading of the existing inter-site links; provide the transmission substations with three separate sources of 60 MVA power; provide a backup source of 18 kV power from SIG to give redundancy to the automatic transfer system; overhaul of the major substations affected (ME9/ME59/ME10); modernisation of the protection system; upgrade of the automatic transfer system. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Creation of a 60 MVA, 18 kV transmission network linking the principal substations October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principal components of the upgrade and extension plan Reorganisation of the 18 kV network on the Meyrin site separation of the machine and general services networks; creation of a secondary 18 kV ring for the WA distribution; provide three independent sources of power for each ring; make the power supply for the computing centre independent of the network feeding the PS ISOLDE/Booster complex. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Reorganisation of the 18 kV network on the Meyrin site October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principal components of the upgrade and extension plan Reorganisation of the 18 kV network of the Prévessin site together with the upgrade of the CCC supply and the safety networks creation of a new secondary substation, BE 91 (to take over the load circuits from BE9); creation of an 18 kV general services ring main on the Prévessin site; upgrade of the safety network for the SPS, the NA, the Prévessin site and the CCC. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Creation of a new secondary substation ME591 BE91 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Upgrade of the CCC supply and safety networks 2012 New Substation BE91 2012 New 3.3 kV power generation station Redundant feeders 18 kV network 3.3 kV safety network 400 V distribution network October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Principal components of the upgrade and extension plan Overhaul of the 18 kV network of the SPS replacement of all underground cables of the 18 kV stable and pulsed networks, along with the SMB cables and the 3.3 kV safety power main; overhaul of the 18 kV substations of the auxiliary buildings (BAs); overhaul of the North Area safety network; overhaul of the 18 kV substations of the North Area. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Replacement of all 18 kV SPS cables Power cables 3.3/18/66 kV, control cables and optical fibres  90 km in 7 km long trenches Tubes buried in 2011 Cables pulled in 2012 Cables connected and commissioned during LS1 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Replacement of all 18 kV SPS cables 1971 18 km cable > 80 joints 2012 18 km cable 10 joints October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Organization of the Project … in stages Stage 1 during the LS1 In the Prévessin site, creation of substation and upgrade of the 3.3 kV safety network the SPS, the NA which will meet the needs of the CCC and the SPS, with independent diesel-generator sets and increased capacity In the West Area of the Meyrin site, creation of a 66 kV source and overhaul of the substation Overhaul of the 66 kV protection system Continuation of the overhaul of the 18 kV secondary network of the SPS. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Organization of the Project … in stages Stage 2 during LS2 overhaul of the ME9 substation; installation of a second feeder to the CERN 400 kV system including a 400/66 kV transformer; upgrade of the automatic transfer system; continued overhaul of the 18 kV distribution network feeding the SPS and the Meyrin site. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Organization of the Project Stage 3 during LS3 overhaul of the ME10 substation; upgrade of the MP7 inter-site link to 60 MVA installation of a 70 MVA 66/18 kV transformer as a hot spare; overhaul of the secondary 18 kV distribution network supplying the NA. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Schedule & Budget Consolidation Projects Upgrade Projects 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Total Approved budget 6,407 5,060 5,838 5,839 3,406 1,798 31,846 Required payment budget 9,200 3,700 4,000 4,100 3,500 35,700 Consolidation SPS power cables (EL-SPS) 8,500 1,000   9,500 Consolidation 66 kV protection system (EL-PS) 500 300 1,800 Consolidation Meyrin West Area (EL-PS) 1,500 600 3,600 Consolidation Prevessin North Area (EL-SPS) Consolidation substation SPS-5 (EL-SPS) 200 700 400 1,300 Consolidation substation SPS-4 (EL-SPS) 2,500 Consolidation substation SPS-2 (EL-SPS) 2,000 Consolidation substation SPS-1 (EL-SPS) Consolidation substation SPS-6 (EL-SPS) Consolidation substation SPS-3 (EL-SPS) Consolidation LHC 18 kV protection system (new) Upgrade Projects 7,500 8,200 4,400 3,400 5,000 45,000 New 66kV power line to Meyrin (EL-NET2025) 1,400 New substation MEH59 (EL-NET2025) 2,200 1,700 4,500 New substation BE91 (EL-NET2025) 7,200 Upgrade substation BE (EL-NET2025) 800 Upgrade ME59 (EL-NET2025) 1500 5,200 Upgrade loop 513 + ME4 Upgrade power lines ME59 --> ME9 1,200 Upgrade power lines ME9 - SEM12 - ME10 3,000 Mew substation 220 MVA Bois-Tollot Upgrade ME9 Upgrade ME10 Upgrade substation SEM12 LHC1 October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System

Summary Ageing equipment and circa 40% of power increase for the next 15 years make mandatory the upgrade & consolidation of the CERN distribution infrastructure 80 MCHF is required for the budget of this upgrade & consolidation program; an average of 6 to 8 MCHF/year is required in the long term to maintain the CERN infrastructure operational Substations, cables and protections systems must be consolidated Transport network, safety network and a redundant link to Bois Tollot are the main upgrade projects. October 24th, 2012 Review of the Project for the Consolidation and Upgrade of the CERN Electrical Distribution System