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LHC UPS Systems and Configurations: Changes during the LS1. LHC Beam Operation Committee 11 February 2014. V. Chareyre / EN-EL. 1. EDMS No. 1354977. 11/02/2014. LHC Beam Operation Committee Changes in UPS Configurations . Outline UPS systems and replacement project during LS1
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LHC UPS Systems and Configurations: Changes during the LS1 LHC Beam Operation Committee 11 February 2014 V. Chareyre / EN-EL 1 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations Outline • UPS systems and replacement project during LS1 • New configuration in the alcoves and LHC odd points • New configuration in LHC even points • New powering interlock rules • EMC considerations • Conclusion 2 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations UPS Systems for the LHC • Critical equipment around the LHC powered by Uninterruptible Power Supply (UPS) systems • QPS (Quench Protection System), Beam Dump System, Beam Loss Monitor, etc. Machine Protection • Cryogenics and vacuum control systems, power converters auxiliary circuits, etc. Machine Availability • UPS principle Continues to provide power to critical loadswhenever the input power fails for the time given by the backup battery • Nominal conditions:load powered via the double conversion path • Input source failure:the load remains supplied by the inverter using the battery stored energy • Load automatically transferred to the bypass line in case of: • Internal UPS failure • End of battery autonomy (requires bypass AC source available) • Short-circuit or overload on the downstream distribution (unlikely) • Fully automatic, load transfers < 1 ms 3 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations LHC UPS Systems Replacement Project • Replacement of the existing APC Silcon UPS systems during the LS1(see EDMS 1151991) • Project motivations: • Improve the reliability • Decrease the failure rate • Minimize LHC run time losses • Change of UPS system topology: come back to the conventional double conversion UPS topology (with output isolation transformer) Double Conversion Delta Conversion 4 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations Basic Requirement for the QPS • Basic requirement for a safe powering: 2 independent power paths and protected by upstream UPS systems • So-called F3 and F4 power lines distributed all along the tunnel • QPS redundant equipment connected to F4 5 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations UPS Configurations before the LS1: Alcoves (REs) and Odd Points • Basic requirement: 2 independent power paths and protected by upstream UPS systems • No link between both UPS units • UPSs interfaced with the Powering Interlock Controller (PIC): Magnet powering stopped when loosing one UPS Output UPS power protected 6 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations New UPS Configurations in the Alcoves (REs) and Odd Points • 3rd UPS (UPS backup) poweringthe bypass of both UPS F3 and UPS F4 = Stand-by redundancy • ‘Natural’ redundancy:no communication busbetween the 3 UPS units Distribution Unchanged Output UPS power protected 7 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations Tolerance to the First Failure • Example: UPS F3 internal failure • UPS F3 transfers to bypass instantaneously • UPS backup takes over the F3 load • 2 power paths still protected • After a failure, we come back tothe same situation as today(but with conventional UPS systems!) • Failure of a second UPS in the same zone will stop the magnet powering (PIC triggered) Output UPS power protectedOutput UPS power NOT protected 8 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations UPS Configurations in LHC Even Points (Before 2009) • 2 parallel-redundant UPS systems in: • UA (IP left side) • US • UA (IP right side) 9 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations UPS Configurations in LHC Even Points: before LS1 • Redundant QPS equipment powered from the UPS system located in the adjacent zone • F3 and F4 lines always powered from 2 different redundant UPS configurations (one in US, one in UA) • Allowed to preserve parallel-redundant UPS systems in UAs and USs • Was already tolerant to the first UPS failure (in each zone) 10 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations New UPS Configurations in LHC Even Points • Distribution remains unchanged • Standby redundancy applied in UAs and USs • F3 and F4 lines still powered from 2 different redundant UPS configurations (one in US, one in UA) 11 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations Tolerance to the First Failure (in each Zone) • Example: failure of the first UPS in UA • Transfers to bypass instantaneously • UPS backup takes over full load in UA • Redundant power paths still protected • Failure of one UPS in the adjacent zone (US in this case) is allowed • Failure of 2 UPS units in the same zone will stop the magnet powering (PIC triggered) 12 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations New Powering Interlock Rules • One single UPS failure = 2 power paths still protected = No PIC triggered • New rules: • Magnet powering can continue upon one single UPS failure • Machine can start with 2 UPS systems out of 3 in the alcoves and LHC odd points • Machine can start with one UPS system out of 2 in the UA and US zones • New UPS configurations allows to wait for the next stop for repairing an UPS failure • Gives us more time for preparing and optimizing the intervention • UPS redundancy restored(and improved) • Increases availability for all users, including EN-EL for fault repairs 13 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations New UPS Systems – EMC Considerations • APC Silcon UPS systemswell-known to produce noise at 8 kHz • High frequency noise caused byswitching transistors (IGBTs) for creatingthe sine wave at the output • Switching frequencies varies according tothe UPS manufacturer and the design • New UPS specified according to applicable standards (IEC-62040-2) • With the objective of attenuating perturbation at around 8 kHz:reduce noise level or shift it to higher frequencies (MHz frequencies are damped by distribution cables) 14 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations New UPS Systems – EMC Performance • Industrial double conversion BORRI UPS selected from invitation to tender • New UPS fully compliant with required standard (IEC-62040-2: EMI and EMC) • CERN internal (re-)qualification of the new UPS with the help of TE-EPC • Noise immunity (UPS = victim) • Burst immunity (high frequency, low power): within IEC standards • Surge immunity (lightning, high power): very good (2 x IEC standard levels) • Noise emission (UPS = aggressor) • EMC conducted noise on AC input/output lines created by the UPS: within IEC standards • UPS output (< 100 kHz): the peak at ~8 kHz (now at ~7 kHz) is reduced by a factor 5 • UPS output (> 100 kHz): another peak appears at ~1.3 MHz (but still 4 times lower than the existing at 8 kHz) 15 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations EMC Performance Comparison 0.4Vrms @ 1MHz 3Vrms @ 8kHz 16 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations EMC Performance – Situation Assessment in the Tunnel UPS output 5 m Downstream distributionswitchboard Downstream distributionswitchboard with UPS OFF 150 m Local distribution in tunnel Local distribution in tunnel with UPS OFF 17 EDMS No.1354977 11/02/2014
LHC Beam Operation Committee Changes in UPS Configurations Conclusion • Change of UPS system topology: • Conventional double conversion topology much more reliable • New UPS system network configuration • Delocalization in points 5, 7 and 8 (R2E project) • UPS network majorly improved during LS1: • Safe powering for machine protection system with independent and redundant paths • Availability increased for all users and thus for LHC operation • Tolerance to the first UPS failure in each zone • Noise in the 8 kHz range reduced with new UPS systems • Noise in the MHz range: ‘false’ problem since noise is attenuated along the distribution cables • Up to now: ~80 new UPS BORRI installed and in operation on surface and underground, no problem reported today • Filtering solution (MHz) being studied with TE-EPC 18 EDMS No.1354977 11/02/2014