Transcript Upgrade of the QPS Electrical Systems of the DYPB`s Housing the

DYPB / DQLPU – Local Quench Protection Facilities for the Arc Dipoles
TE/MPE/EE - LHC
Project for Upgrade of the Electrical Circuits, the Powering Scheme and
the Quench Heater Supervision for Enhanced Monitoring
Topics:
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Knud 8/3/2012
The motivation for undertaking the upgrade
Description of the implementation of the required modifications
The expected performances
The strategy for the execution
Cost estimations
Schedule & Planning
Upgrade of the QPS Electrical Systems of the DYPB’s
TE/MPE/EE - LHC
Reasons for the proposed changes:
1. DQHDS: The present discharge voltage measurements are considered insufficient for
proving the integrity and conformity of the quench heater circuits and as a tool for an
early warning of circuit failure
- Defects (cracks) have been detected in at least one dipole heater circuit.
The flaw is considered as a potential risk of strip rupture in a certain batch of dipoles
but also other types of failures have been observed.
- It is feared that an electrical arc at the level of a strip heater can damage
the coil insulation to a point where the withstand to ground is being affected.
- If detected early enough the heater system can be reconfigured with the use of LF
heaters and the suspect strip will be disconnected. The re-connection is made in the
Crawford box.
- So far 8 LHC main dipoles have actually experienced heater circuit failures and
were reconfigured (C15R1,A22R1,C32R1,A21L3,C17R4,C31R4,A32L7 and B21L8).
- As a consequence full-voltage test discharges have been avoided in the main circuits
for the last two years – now replaced by our LV discharge (from 100V).
- Operation at nominal current and the future magnet training campaign stress the
need for the more powerful monitoring tools which will be provided by the
suggested upgrade.
Upgrade of the QPS Electrical Systems of the DYPB’s
TE/MPE/EE - LHC
Reasons for the proposed changes:
2. Powering: The LV powering scheme for energizing the detector electronics of the iQPS
system for the main magnets (DQLPU crate) was built and has remained non-redundant
from a UPS point-of-view, also after the introduction of the nQPS system which was
designed with UPS1/UPS2 powering redundancy
- The DQQDS (SymQ) system will, to a certain extend, act as back-up for the ‘asymmetric’
detection of iQPS in case of a failure of UPS1 (now UPS2). However, with the higher
thresholds longer detection time can be expected.
- The change to a UPS-redundant powering scheme would require important changes to
the DQLPU motherboard and back-panel. The ‘crash program’ of 2008/9 did not allow
such modifications. The update of the local protection unit would be an appropriate
occasion.
- Although considered very reliable, the commercial ‘Syko’ tri-volt, switched-mode
converters used in the DQLPU s have recently shown some weaknesses (~25 units did
not restart after repowering this winter and some evidence that the current rushes
observed on the F3 UPS net are caused by the ‘Syko’s’).
- The 872 CERN-made (QPS/EPC) linear power supplies with four output stages (the
Power-Packs DQLPUS) have worked impeccably for two years and could be the model for
a new version of converter suitable for the iQPS upgrade.
- It would be interesting to integrate the signal and power patches, introduced with
the nQPS, into a new interface (shuffling) module required for the upgrade.
Upgrade of the QPS Electrical Systems of the DYPB’s
TE/MPE/EE - LHC
Based on these considerations, the proposal for modifications to the electrical systems and
interconnections of the existing Local Protection Units consists in:
• Replacing the existing ‘Crawford’ box, the ‘Syko’ power source and all the patches with
a single, new Interface Module (DQLIM) which will contain ALL the requested components
and features, incl. most elements of the new enhanced heater circuit supervision.
- The ‘Crawford’ shuffling module was never optimized from the point of
view of volume and maintaining it would leave insufficient space for the
new items.
- In order to protect all components they must be mounted inside the frame
of the DYPB rack
- Such a topology would lead to less ‘external’ electrical interconnections.
- The complete module can be pre-manufactured resulting in short
installation times.
- The new module can be tailor-made to the requirements for e.m. shielding.
- The new module can, if decided so, incorporate the expensive connectors and other items
recuperated from the dismantled ‘Crawford’ unit.
Upgrade of the QPS Electrical Systems of the DYPB’s
TE/MPE/EE - LHC
•Housing the following new and old sub-systems inside the new Interface Module:
- Two identical, linear power supplies (DQLPUR) each with four secondary outputs (@15 V
and 5.4 V), inspired by the design, component selection and experience from the
creation of the nQPS Power Packs.
- An energy storage module (Super capacitor bank) for each new Power Pack.
- The power distribution from the redundant converters to the crates DQLPU-A and DQLPU-S
- Four screened, pulse current transformers, with their individual bias system (housed
in individual compartments for additional magnetic decoupling). Bias system requires a
200 mA current source.
-The connections for the injection of the DC heater test current (from the DQLPU-A), the two
separation / isolation switches (one per pole), the anti-return power diodes and the currentlimiting resistors for the voltage measurement lines.
- The electrical connections of the existing ‘Crawford’ box and the signal- and power
patches, adapted to the new configuration.
More details are given in the ECR: ‘Installation of Enhanced Quench Heater
Supervision System for the LHC Main Dipole Magnets’ - ready for circulation.
Existing Interconnection Scheme for iQPS & nQPS, Power and Signals between the Individual Elements
Valid for Dipole ‘B’ position
Proposed Interconnection Scheme for iQPS & nQPS, Power and Signals between the Individual Elements
Valid for Dipole ‘B’ position of the Upgraded DYPB
Existing Interconnection Scheme for iQPS, Power and Signals between the Individual Elements
Valid for Dipole ‘C’ position (similar for ‘A’ position)
Proposed Interconnection Scheme for iQPS Power and Signal transmission between the Individual Elements
Valid for Dipole ‘C’ position (similar for dipole ‘A’ position) of the Upgraded DYPB
Components of the existing DYPB / DQLPU / DQLPU-S / DQHDS/ ‘Crawford’ box
Local Protection rack DYPB
for dipole position ‘B’
The ‘Crawford box’ for a dipole protection unit
DQLPUS
The New Components 1: Broadband Pulse Current Transformers (CT)
TE/MPE/EE - LHC
Two prototype pulse measurement transformers with
shielding case and precision burden resistor. One made for
operating with magnetic bias from one-winding 200 mA
bias current
•Housing
- Two
Burden resistor: 100Ω, 0.1%, ¼ W
Current measurement
transformer before housing
- Precision current measurements of the 4 simultaneously triggered heater discharge pulses are provided by 4
identical , shielded CT’s, designed specially for the 80 Apeak τ = 80 ms pulse current and equipped with precision
Burden resistors.
- To minimize distortion of the pulse shape, the ferrite –cored CT has been designed for values of leakage
inductance and distributed capacitance as well as a high open-circuit inductance.
- Magnetic Bias allows important reduction in volume and cost (for same measurement performance). The bias
requires a 200 mA dc excitation current.
- Measurement accuracy depends on the dI/dt: 1 % at 1τ, 2 % at 2τ (expected, tbc)
- Producer: ‘Lilco Ltd.’, Isle of Orkney, UK.
- The two prototype trfo’s are ready for testing. To be performed in an accredited Test Institute (IPH - Prüffeld
für Elektrische Hochleistungstechnik" GmbH, East-Berlin).
- Unit cost of the CT‘s (budget prices): Un-biased type: 100 CHF/unit, biased type: 70 CHF/unit.
TE/MPE/EE - LHC
The New Components 2: The Power Packs for iQPS Redundant Powering
DQLPUR
The new natural-convection air-cooled power modules shall be derived from the Power Packs (DQLPUS) which were developed by QPS
and Industrialized by EPC for the nQPS .
They shall supply two independent, regulated DC voltage outputs:
•DC output 1a: +5.4 V, +/- 2%, with fully floating output (2.5 kV isolation)
•DC output 1b: ±15 V, +/- 10%, with fully floating output (2.5 kV isolation, DC outputs 1a and 1b shall share the same reference
voltage)
•DC output 2a: +5.4 V, +/- 2%, with one ground potential reference
•DC output 2b: ±15 V, +/- 10%, with one ground potential reference, for powering the relays of the DQHDS and the DAQ systems (DC
output 2a and 2b must share the same ground potential reference)
•The current ratings of the two 5.6 V outputs will be fixed as soon as the power consumptions have been determined.
•The topology is based on input transformers for voltage step-down and galvanic isolation, relays on the power input level to allow for
remote power cycling of the two 5.6 V outputs, diode rectifiers, smoothing capacitors, linear regulators on the LV-side of the toroidal
transformers and super-capacitor banks for voltage hold-up of the two 5.6 V outputs.
•Opposite the nQPS Power Packs, which are mounted separately on the frame of the DYPB racks, the new supplies will be designed as
a very compact version for insertion into the DQLIM interface module. The heat dissipated from the transformers and the linear
regulators shall be conducted outside the crate.
•In total 2’500 units, incl. spares are required to cover the needs of the dipole local protection units.
Frame conditions 1: Cost Estimate:
TE/MPE/EE - LHC
Supplies only (based on 100% deliveries from Industry).
Estimations made by scaling using previous contracts of similar supplies
Equipment
Power Packs
iQPS version (DQLPUR)
Shuffling box
DQLIM
Pulse Current
Transformers (bias type)
Associated new sets of
Interconnecting cables
GRAND TOTAL
Unit (or set) cost
CHF
Quantity installed
Quantity Spares
Total cost
CHF
380,-
2464
250
1'031’320
720,-
1232
50
923’040
70,-
4928
100
351’960
350,-
1232
10
434’700
2’741’020
Frame conditions 2: Cost Estimate:
Human Resource Cost (PJAS, FSU)
Estimations made by scaling from previous jobs
TE/MPE/EE - LHC
Work Description
Removal of the Crawford box
and associated cables
Installation/connection of the
new sets of cables
Installation of new Interface
Module (DQLIM)
System Tests – surface building
System Tests - tunnel
Quantity people
(team)
Time per sector
(hours)
Total Cost
Whole Machine
CHF
6
17
32’640
6
8
15’360
6
2 +2
2
9
51
20
17’280
65’280
12’800
Total
Average hour rate used: 40 CHF
TOTAL PROJECT COST FOR EE-SECTION: 2’884’380 CHF
143’360
Frame conditions 3: Planning – Schedule
Preliminary ! Assumption: No Marked Survey and Restricted Tender Procedure !
TE/MPE/EE - LHC
Activity:
Target date for
completion
Concept / design ready for prototype:
DQLPUR
14 May 2012
Concept / design ready for prototype:
DQLIM
5 May 2012
Two prototypes ready for type testing
and endurance tests
DQLPUR
Two prototypes ready for type testing
and endurance tests
DQLIM
Successful completion of testing of
the CT prototypes
Successful completion of type testing
of first complete prototype system
Production Readiness Review (CERN)
Orders placed with industry
Production Readiness Review with
Industry
Deliveries for 1st Sector
Delivery rate
21 June 2012
2 July 2012
1 May 2012
31 Aug 2012
Mid-Sept 2012
Early Oct 2012
Mid Nov. 2012
End January 2013
1 sector/month