Electrical power distribution in experiments W.Iwanski

Outline Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 225/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 325/10/2011 ESE seminarW.Iwanski

Powering grid at CERN 425/10/2011 ESE seminarW.Iwanski

Major power consumers at LHC 525/10/2011 ESE seminarW.Iwanski

Electrical supply of the LHC experiments ALICE supply 625/10/2011 ESE seminarW.Iwanski

Electrical supply of the LHC experiments  Separation of the Machine network from the LHC General Service network in each experiment  Individual 18/0.4 kV transformers to feed separate systems  Filters on the Machine network of all LHC experiments 725/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 825/10/2011 ESE seminarW.Iwanski

Quality of power supply at CERN (Extract from the document LHC-EM-ES-0001 rev 2.0) 925/10/2011 ESE seminarW.Iwanski

P (active) P P … active Power Q (reactive) Q Q … reactive Power S S … apparent Power S Phasor DiagramReal Life without SVC What is reactive power? Source: K.Kahle 1025/10/2011 ESE seminarW.Iwanski

P (active) P P … active Power Q (reactive) Q Q … reactive Power S’ S … apparent Power S Phasor DiagramReal Life with SVC What is reactive power? Source: K.Kahle -Q SVC 1125/10/2011 ESE seminarW.Iwanski

reactive power 50% SPS TCR 150 Mvar filters -130 Mvar SPS mains 90 Mvar Reactive power compensation Source: K.Kahle 1225/10/2011 ESE seminarW.Iwanski

Reactive power taken from EDF is almost zero! Reactive power consumed by SPS Mains Reactive power generated by SVC Reactive power compensation Source: K.Kahle 1325/10/2011 ESE seminarW.Iwanski

TCR for PSB  Reactive power compensation Up to 130 MVAr at LHC  Filtering of harmonic distortions SPS: 20% --> 0.5%  Voltage stabilization SPS: 14% --> 0.75%  …. But when being energized, they generate fast transient on the powering network Turning them ON is coordinated by the CCC with experiments Benefits of having the Static Var Compensators 25/10/2011 ESE seminarW.Iwanski14

Perturbations on powering grid recorded at CERN Source: D.Arnoult 1525/10/2011 ESE seminarW.Iwanski

Power Quality Monitor  PQM monitors state of the filters in the experiment’s zone as well as on the LHC loop  It spies on alarms from the analyzers recording events happening on the 18 kV Machine and GS LHC loop networks  PQM is ready to monitor signals from local analyzers to be connected to register events on selected 400 V branches  Acknowledgeable alarms are launched on the Alarm screen in the Control Room whenever supervised equipment changes its state  Applications developed for the moment for Atlas and Alice experiments. ALICE Power Quality Monitor synoptic view ATLAS Power Quality Monitor synoptic view 1625/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 1725/10/2011 ESE seminarW.Iwanski

Auto-transfer Source: G.Cumer/F.Duval 18 Auto-transfer process managed by the controllers of the bus-bars BE9, SEM12 and ME9 during the Major Event of 07/ /10/2011 ESE seminarW.Iwanski

Auto-transfer Source: G.Cumer/F.Duval 19 Auto-transfer process managed by the controllers of the bus-bars BE9, SEM12 and ME9 during the Major Event of 07/2011 Loss of supply for the GS Network 25/10/2011 ESE seminarW.Iwanski

Auto-transfer Source: G.Cumer/F.Duval 20 Auto-transfer process managed by the controllers of the bus-bars BE9, SEM12 and ME9 during the Major Event of 07/2011 Attempt to re-feed the GS from the Meyrin side 25/10/2011 ESE seminarW.Iwanski

Auto-transfer Source: G.Cumer/F.Duval 21 Auto-transfer process managed by the controllers of the bus-bars BE9, SEM12 and ME9 during the Major Event of 07/2011 Loss of Meyrin supply due to inrush current 25/10/2011 ESE seminarW.Iwanski

Auto-transfer Source: G.Cumer/F.Duval 22 Meyrin side re-powered from the Swiss supplier Auto-transfer process managed by the controllers of the bus-bars BE9, SEM12 and ME9 during the Major Event of 07/ /10/2011 ESE seminarW.Iwanski

Redundancy of supply: Re-powering  Re-powering is used at different levels of hierarchy to provide an alternative source of power in case of a failure or a maintenance up- stream  Typically, the re- powering is taken from the general service network 2325/10/2011 ESE seminarW.Iwanski

Redundancy of supply: Doubled systems Source: B.Saint-Sulpice  Additional transformer provides power from other network, following switchboards re- power each other  Redundant compressors are fed from different networks Modifications of supply of the Cryogenic system in Atlas after the major event in 07/ /10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 2525/10/2011 ESE seminarW.Iwanski

AUG  Daisy-chain of AUG sensors in particular zone  Cut of supply in the zone at the level of 18/0.4 kV transformer  Supervision by ENEL SCADA  Generation of L3 alarms  Interface to DSS of experiments 2625/10/2011 ESE seminarW.Iwanski

Types of supply See mains perturbations ? Switched off by AUG ? Back up by Diesel set ? Downtime ? Normal EBDYes No Yes Mains downtime Normal EXDYesYes or No*Yes* or No Yes Mains downtime Assured EAD Yes 30s to 90s Safety ESD YesNoYes 30s to 90s UPS EODNoYes or No No Battery autonomy : 10min to 2h 48 VDC ECDNo Yes No Battery autonomy : 2h to 3h * Cas unique EXD4/15A Levels of availability of electrical supply 2725/10/2011 ESE seminarW.Iwanski

Diesel supply  Supply of safety installations Elevators AUG Anti-panic lighting Ventilation Back-up of 48 VDC supply …  Back-up of UPS installations  Detector-specific installations which shall provide power in emergency cases (fed from experiment Diesel generators) Magnet Heaters in Atlas Chillers of the Thermosiphon in Atlas Diesel generator Normal supply Safe power: Normal supply when power is ON or Diesel power during a power cut. There is always a short voltage loss before Diesel starts feeding the network 2825/10/2011 ESE seminarW.Iwanski

UPS with a little autonomy  UPS and the by-pass are fed from the normal network  Double AC/DC DC/AC conversion + batteries are used for filtering perturbations on the mains.  Autonomy of UPS is not important but is long enough to be able to shut down equipment fed from the UPS in case of a power cut. 2925/10/2011 ESE seminarW.Iwanski

UPS with a significant autonomy  UPS and the by-pass are fed from the normal network  During a power cut the UPS power is available as long as batteries allow (typically not longer than 2 hours) 3025/10/2011 ESE seminarW.Iwanski

UPS with a Diesel back-up EBD1/15  UPS is fed from the safe network while the by- pass from the normal network  During a power cut, safe network is fed from Diesel which practically assures unlimited UPS power availability 3125/10/2011 ESE seminarW.Iwanski

Redundant UPS with a significant autonomy + Diesel back-up + power management  UPS is fed from the safety network while the by-pass fed from the normal network  Redundant UPS increases power availability and is convenient for long operation  During a power cut, safety network is fed from Diesel which practically assures unlimited UPS power availability  In case of a power cut and the Diesel failure, a PLC manages autonomy of the UPS by cutting less important users after 10 min 3225/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 3325/10/2011 ESE seminarW.Iwanski

9 Global view of electrical SCADA system Source: S.Infante 25/10/2011 ESE seminarW.Iwanski34

Drawer number 2 HMI DCS ModBus/TCP/IP ModBus/JBus DIRIS Drawer number 1 Concentrator Crate Acquisition Crate ModBus/JBus ENS SSS HMI DCS RACK Concentrator Crate ModBus/JBus ENS TWIDO Distribution chassis ModBus/JBus ModBus/TCP/IP ATLAS/CMS ALICE/LHCb Supervision and control architecture in experiments Source: S.Infante 25/10/2011 ESE seminarW.Iwanski35

Basic infrastructure for controlling and monitoring Rack’s supplying boxConcentrating PLC Expert panel  Concentrating PLC makes state of the system available to the supervising database (CCC) and user application (DCS)  Concentrating PLC communicates with the local PLCs in supplying boxes/cabinets (ATLAS/CMS) or reads state of powering drawers (ALICE/LHCb)  Local PLCs execute ON/OFF commands on powering breakers and monitor their state (opened/closed/tripped) LHC Control Room (CCC) Experiment’s Control Room Powering drawers 3625/10/2011 ESE seminarW.Iwanski

Rack Control applications PLC in the supplying box above the rack allows for monitoring of local breakers in the repartition box (ATLAS/CMS) 3725/10/2011 ESE seminarW.Iwanski

Rack Control applications One supplying drawer brings power to few racks. No monitoring is possible of power distribution inside the rack (ALICE/LHCb) 3825/10/2011 ESE seminarW.Iwanski

Control of supply of computers Powering of computers installed in one rack requires special attention:  Six AC Smart Start modules controlled via Ethernet provide staggered start-up of 12 blocks of 4 outlets (ALICE, 6 racks of that kind)  Two breakers controlled by the PLC via Ethernet feed two powering lines having NTC thermistors on each phase (ATLAS, ~100 racks of that kind 3925/10/2011 ESE seminarW.Iwanski

Electricity Distribution Monitor  Simple but very reliable system, used for monitoring of the electrical infrastructure  Shows status of all electrical supplying cabinets important for experiment  System based on voltage presence sensors being read by the ELMB card interfaced to a local DCS station  Application developed by Atlas and integrated with the global monitoring environment of the experiment 4025/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary 4125/10/2011 ESE seminarW.Iwanski

Testing and maintenance of electrical infrastructure  In order to keep operability, regular testing of active components is required. Possibly in nominal conditions Monthly testing of Diesel generators Yearly testing of the Auto-transfer  Nominal conditions are not easy to achieve as experiment equipment typically is preventively switched off to avoid unnecessary losses. This does not help to tune settings of the protective circuits (see Major Event of 07/2011)  Periodic maintenance is planned typically for the LHC shut- down periods UPS: every year  Redundancy of the UPS allows to keep the UPS supply running Diesels: every year Switchboards: every 5 years Transformers: every 3 years 4225/10/2011 ESE seminarW.Iwanski

Lessons learnt from the Major Events  Many UPSs ran out of batteries before the GS network came back. It can happen but it’s not comfortable situation when supervising systems fed from the GS network via UPS are not running anymore while supervised electronics fed from the Machine network is working fine. Either to move supply of UPS from the GS network to the Machine one or supply UPS from both networks  Atlas lost big volume of Helium when long cut on the GS network caused stoppage of the cooling, the Shield compressors and 400 V distribution for the Cryo services for long Redundant Shield compressors to be fed from the GS and Machine networks Additional transformer fed from the Machine network to provide redundant supply for 400 V distribution of the Cryo services 4325/10/2011 ESE seminarW.Iwanski

Summary  Monitoring and control of the electrical infrastructure are key elements to provide efficient operation  Despite being in operation since several years, the electrical infrastructure is still evolving. Consolidation work is in progress  While the robustness of power supply assures quick recovery from crisis situations, the regular maintenance and testing guarantees long operability 4425/10/2011 ESE seminarW.Iwanski

Supplying network at CERN Power quality Redundancy of supply Power availability Monitoring and control of electrical infrastructure Operation Summary Thank you for your attention ! 4525/10/2011 ESE seminarW.Iwanski

Supporting slides 4625/10/2011 ESE seminarW.Iwanski

Power delivered to the LHC experiments during operation 4725/10/2011 ESE seminarW.Iwanski

Active and reactive power consumed from the CERN network 4825/10/2011 ESE seminarW.Iwanski

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Parent-child architecture for DCS PLC Concentrator DCS ENS TGBT ABB Coupler TWIDO PLC RACKS HMI CPU Coupler Normal distribution JBus Normal distribution SDX1 1 TGBT – 6 FEEDERS 6 DISTR. SWITCHBOARDS – 40 FEEDERS Source: S.Infante 5125/10/2011 ESE seminarW.Iwanski

PLC Concentrator DCS ENS TGBT ABB INPUT OUTPUT RACKS HMI CPU Coupler Normal distribution Parent-child architecture for DCS UX15 INPUT OUTPUT INPUT OUTPUT Arrivée 2 TGBT 400V - 10 FEEDERS 6 DISTRIBUTION SWITCHBOARDS Source: S.Infante 5225/10/2011 ESE seminarW.Iwanski