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LHC UPS Systems and Configurations: Changes during the LS1
V. Chareyre / EN-EL
LHC Beam Operation Committee
11 February 2014
EDMS No. 13549771 11/02/2014
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 CommitteeChanges 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
Rectifier
Inverter
StaticSwitches
NormalAC source
BypassAC source
Power to load
Battery
LHC Beam Operation CommitteeChanges in UPS Configurations
EDMS No. 1354977 11/02/2014
Rectifier
Inverter
StaticSwitches
NormalAC source
BypassAC source
Power to load
Battery
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)
4
Delta converter
Main converter
NormalAC source
Bypass
Power to load
Battery
StaticSwitches
Delta Transformer
Delta
Conversion
Double
Conversion
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges 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
EOD F3 EOD F4
Distribution Line F3
Distribution Line F4
- QPS1- CRG- VSC- BLM
- QPS2
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges 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
6
EOD F3 EOD F4
Distribution Line F3
Distribution Line F4
- QPS1- CRG- VSC- BLM
- QPS2
EBD Normal Network
UPS F3 UPS F4
Output UPS power protected
UPSs interfaced with the Powering Interlock Controller (PIC): Magnet powering stopped when loosing one UPS
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
EOD F3 EOD F4
Distribution Line F3
Distribution Line F4
UPS F3
- QPS1- CRG- VSC- BLM
- QPS2
UPS F4
UPS Backup
EBD Normal Network
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
7
Output UPS power protected
DistributionUnchanged
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
EOD F3 EOD F4
Distribution Line F3
Distribution Line F4
UPS F3
- QPS1- CRG- VSC- BLM
- QPS2
UPS F4
UPS Backup
EBD Normal Network
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 to
the same situation as today(but with conventional UPS systems!)
8
Output UPS power protectedOutput UPS power NOT protected
Failure of a second UPS in the same zone will stop the magnet powering (PIC triggered)
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
UPS Configurations in LHC Even Points (Before 2009)
9
2 parallel-redundant UPS systems in:
UA (IP left side) US UA (IP right side)
Canalis in UA (F3)
UA (left)
Distribution Line F3
- QPS1- CRG- VSC- BLM LHC Tunnel
US
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
UPS Configurations in LHC Even Points: before LS1
10
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)
Canalis in UA (F3)
Racks QPS2 in UA (F4)
- QPS2
UA (left)
Distribution Line F4
Distribution Line F3
- QPS1- CRG- VSC- BLM
- QPS2
LHC Tunnel
US
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
New UPS Configurations in LHC Even Points
11
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)
Canalis in UA (F3)
Racks QPS2 in UA (F4)
- QPS2
UA (left)
Distribution Line F4
Distribution Line F3
- QPS1- CRG- VSC- BLM
- QPS2
LHC Tunnel
US
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges in UPS Configurations
Tolerance to the First Failure (in each Zone)
12
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)
Canalis in UA (F3)
Racks QPS2 in UA (F4)
- QPS2
UA (left)
Distribution Line F4
Distribution Line F3
- QPS1- CRG- VSC- BLM
- QPS2
LHC Tunnel
US
EDMS No. 1354977 11/02/2014
LHC Beam Operation CommitteeChanges 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 CommitteeChanges 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
LHC Beam Operation CommitteeChanges in UPS Configurations
-5 0 5 10 15 20 25 30 35 40 45 50-140
-120
-100
-80
-60
-40
-20
0
Mag
nitu
de s
pect
rum
[dB
]
Frequency [kHz]
EDMS No. 1354977 11/02/2014
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)
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LHC Beam Operation CommitteeChanges in UPS Configurations
EDMS No. 1354977 11/02/2014
EMC Performance Comparison
16
LHC Beam Operation CommitteeChanges in UPS Configurations
EDMS No. 1354977 11/02/2014
0.4Vrms @ 1MHz
3Vrms @ 8kHz
EMC Performance – Situation Assessment in the Tunnel
17
LHC Beam Operation CommitteeChanges in UPS Configurations
EDMS No. 1354977 11/02/2014
UPS output
Downstream distributionswitchboard
Downstream distributionswitchboard with UPS OFF
Local distribution in tunnel
Local distribution in tunnelwith UPS OFF
5 m
150 m
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
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LHC Beam Operation CommitteeChanges in UPS Configurations
EDMS No. 1354977 11/02/2014