Frédérick BORDRY – LHCMAC 22- 6th December 2007 Review of the experience of LHC powering: short-circuit tests and sector 7-8 and start of powering sector 4-5 Frédérick Bordry Review of the experience of LHC powering: short-circuit tests and sector 7-8 and start of powering sector 4-5 Frédérick Bordry 1.Short-circuit test review 2.Sector 7-8: what was done? Some highlights 3. Sector 7-8: what was not done? 4. What can we do faster when powering for the next sectors ? 5. What can we not do faster when powering for the next sectors ? 1.Short-circuit test review 2.Sector 7-8: what was done? Some highlights 3. Sector 7-8: what was not done? 4. What can we do faster when powering for the next sectors ? 5. What can we not do faster when powering for the next sectors ?

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Short-circuit tests are not only power converter tests: energy extraction tests, DC cables tests, AC network conditions, cooling and ventilation, interlocks, control,… Short-circuit tests (SCT)

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Short-circuit tests

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Circuit Type Sector LHC kA Independently Powered Dipoles Independently Powered Quadrupoles A with Energy Extraction A Energy Extraction in Converter A no Energy Extraction A Correctors TOTAL Circuit Type Sector LHC A Closed Orbit Correctors Short-circuit tests

Frédérick BORDRY – LHCMAC 22- 6th December 2007 From October 2005 to September 2007 Short-circuit tests All tests were successfully concluded by a 24h endurance test (16h at ultimate and 8h nominal)

Frédérick BORDRY – LHCMAC 22- 6th December 2007 General Services: AC Distribution (P,Q, THD) WorldFip fielbus/ WiFI Cooling for Power Converters, Power Cables and Energy Extraction Ventilation (air temperature variation) UPS System Equipment directly linked to the SC circuits: Power Converters 13kA and 600 A EE Systems (+Endurance Tests) Power Cables Control system from equipment to the CCC (Platform to test the software tools) Example: RR77 tests Short-circuit tests

Frédérick BORDRY – LHCMAC 22- 6th December °C FLIR Systems An Infra Red analysis to see what a hand cannot feel at less than 20cm !!! Loose connection Systematic Infra Red (IR) survey 600A cables

Frédérick BORDRY – LHCMAC 22- 6th December 2007 An Infra Red analysis to check everything is OK Systematic Infra Red (IR) survey Y. Thurel 4 racks with 8 * [±600A;±10V] in UA 67

Frédérick BORDRY – LHCMAC 22- 6th December 2007 What did we learn ? Power converters are fulfilling specification but important tests to solve interface problems and coupling problem between circuits (e.g. MB and MQ, 600A circuits, EMC,…) Continuous improvement of PC control and regulation software (FGC : V.99 to V.237) The short circuit tests were essential to validate the power converters in their environment (AC, harmonics, cooling & ventilation, …) Several 24h tests were done twice to confirm DC cabling modification, cooling & ventilations, bad connections, leaks,… Measurement and Validation of the active and reactive power (P,Q) and THD (pt 4 not tested with RF; available P and Q should be confirmed by TS/EL) Control and diagnostics of power elements from the CCC To solve a lot of early failure (“défaut de jeunesse”), especially with the heat runs TO BE READY FOR THE HARDWARE COMMISSIONNING Short-circuit tests A lot of groups worked together in the tunnel

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Hardware commissioning: Sector 7-8 Powering

Frédérick BORDRY – LHCMAC 22- 6th December PIC2 (Power Interlock test with PC connected to the magnets) -Transfer Function Analysis -Power converter and Circuit set-up (Setting of the current loop parameters) (PCC) -Start-up procedure compatible with QPS -Verification of the superconducting splices (PCS) -Powering to Nominal of every circuit with intermediate level ( PLI1… PLI4 => PNO) - Check of the machine squeeze functions (PSQ) - 24-hour run with all the circuits at nominal (PAC) -General emergency stop test (AUG) Powering tests Converters connected to the magnets

Frédérick BORDRY – LHCMAC 22- 6th December Powering Procedures

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Circuit Type Sector LHC kA Independently Powered Dipoles Independently Powered Quadrupoles A with Energy Extraction A Energy Extraction in Converter A no Energy Extraction A Correctors TOTAL Sector 7-8 HW commissioning: released circuits Circuit Type Sector LHC A Closed Orbit Correctors Circuits powered from the arc Limited Current: RB (2 kA), RQD (6.5 kA), RQF (6.5 kA) 3 Only RD2, Inner triplet dipole not available 1 Only RQ4 and RQ Line-N Circuits, 3 spool piece correctors & 2 MQTLH 19 Three Line-N Circuits 3 RCO and inner triplet correctors not available 0 Q4 and Q5 available correctors 7 Total of released circuit 35 Released: 78 R. Saban

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Powering Tests – > History History Sector 78 Dashboard (108/199 circuits in Total)Sector 78 Dashboard ( –Fully Commissioned: 44 circuits 1 x [8kA,8V] converter (RD2) 2 x MQM [6kA, 8V] converters (Matching Q4 & Q5 Quadrupoles) 1 x [±600A,±10V] converter (RQS.L8B1) 8 x [±120A,±10V] converters (Orbit Correctors + RCO.A78B1) 32 x [±60A,±8V] converters (Orbit Correctors) –Partially commissioned: 64 circuits 1 x [13kA, ±180V] converter (Main Dipole) up to 2kA 2 x [13kA,18V] converter (Main Quadrupole) up to 6.5kA 15 x [±600A,±10V] converters up to 200A 46 x [±60A,±8V] converters (Orbit Correctors) Sector 78 – What did we test?

Frédérick BORDRY – LHCMAC 22- 6th December K 4.5K Main dipole circuit powering

Frédérick BORDRY – LHCMAC 22- 6th December 2007

RB successfully started with START_DIDT = 10A/s The FGC regulates dI/dt by controlling dV/dt with a proportional controller New open loop voltage ramp included until I > 1% of I_MIN Blocking voltage during Pre-Mag Main dipole Power Converter Start Up [New algorithm] Start up must avoid rapid voltage changes that can trigger the QPS If current is less than 1% of I_MIN then a blocking voltage must be applied during the pre-mag phase – this winds up the voltage loop integrators This could result in an aggressive start up that could trip the RB QPS so ~6s open loop voltage ramp is now included to make the start up smoother: Q. King

Frédérick BORDRY – LHCMAC 22- 6th December H 7 ppm (100 mA) 2 ppm (20mA) 3 A/s 350 A 45 V

Frédérick BORDRY – LHCMAC 22- 6th December 2007 First current cycle (main dipole) 27th June h27 CET Injection current Imin Fast discharge with switch opened (L/r  100 s)

Frédérick BORDRY – LHCMAC 22- 6th December 2007

Tracking between the three main circuits of sector 78 2ppm Free-wheeling : L/r  23’000 s

Frédérick BORDRY – LHCMAC 22- 6th December 2007 RB decay from 350A takes more than 1 hour with the discharge switch closed New Switch Off algorithm will ramp down the current to 1% of I_MIN (< 4 A) before switching off (<40s) The algorithm will also be used for SLOW ABORT Converter is switched off with V_REF = 2% of V_NEG Voltage is reduced in proportion to the current to smoothly end the ramp to 1% of I_MIN End of a Switch Off ramp on RB dI/dt of ramp down is regulated to be - LIMITS.DIDT by controlling dV/dt with a proportional controller Main dipole Power Converter: Power Off [New algorithm] Q. King

Frédérick BORDRY – LHCMAC 22- 6th December Current loop robustness: L/2r to L/r - Always: static and dynamic I 1 /2 < I 2 < 2xI 1 and I 2 /2 < I 1 < 2xI 2

Frédérick BORDRY – LHCMAC 22- 6th December 2007 RQ4.L8B1 I_MEAS RQ4.L8B2 I_MEAS RQ5.L8B1 I_MEAS RQ5.L8B2 I_MEAS RQ4.L8B1 V_MEAS RQ4.L8B2 V_MEAS RQ5.L8B2 V_MEAS RQ5.L8B1 V_MEAS 0V Close to Limits Squeeze tests (PSQ) : Q4 and Q5 RQ4.L8B2 is close to limit New optic function much improved (15min squeeze) All systems performed as calculated With LHC Software Application LSA: generation of table (I,t) => dI/dt >> between points MQM control touchy during ramp down with 1- Quadrant converter => Good Performance even if the limits are closed D. Nisbet

Frédérick BORDRY – LHCMAC 22- 6th December 2007 I_MEAS = About 1-2ppm pk-pk 1 ms Vout 1300 A 1625 A 6500 A Converter Operation during a sub-converter failure [13kA,18V] converter : (4+1) x [3.25kA,18V] subconverters Tests during 7-8 hardware commissioning 13 kA, 18V 3.25 kA, 18 V At injection current : 860 A Restart of sub-converter 2 V. Montabonnet

Frédérick BORDRY – LHCMAC 22- 6th December 2007

Current Leads badly connected Resistive Current Lead Protection 54 samples V. Montabonnet

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Current Leads badly connected 2 Hours Trip Level Good Cooling Bad Cooling Resistive Current Lead Protection 54 samples V. Montabonnet

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Heat-Run with 44 circuits ( : :30) RB.A78 (2kA) RQF.A78 (6.5kA) RQD.A78 (6.5kA) RD2.L8 (6kA) RQ4.L8 (3.59kA) RQD.A78 (4.21kA) RQS.L8B1 (550A)RCBYH4.L8B2 (72A) RCBYV4.L8B1 (72A) RCBYHS4.L8B1 (72A) RCBYVS4.L8B (72A) RCBYVS4.L8B2 (72A) RCBCH5.L8B1 (80A) RCBCV5.L8B2 (80A) 30 Closed Orbit Correctors (55A) >16h without any fault

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Inner triplet powering (DFBX commissioning, nested converters: decoupling, loop robustness, protection with high time constant and no EE… ) Dipole powering up to 2kA : less than 3 % of the stored energy Quadrupole powering up to 6.5kA (30% of energy) Free-wheel system at high current with large time constant (MB, MQ, IT,…) Only one 600A circuit at nominal (RQS.A78 at 550A) ! High precision OK but low statistics Complete heat run at nominal current (1.1 GJ) Complete AUG test at nominal (partly done but no current in the main circuits) 8kA Q1Q2Q3 6kA I F = I 1 + I 2 I K = I 1 I2I2 V cv 1 V cv2 ±600A V cv3 I1I1 Q2 Sector 7-8: what was NOT done?

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Sector 7-8: what was not done? What can we do faster when powering for the next sectors ? No ELQA at 80 o K then no stop for the cool down Settings of the current loops (TFA done; to do again only if) and more generally automatic FGC configuration Start-up of the converters compatible with QPS 100mV threshold for QPS (nominal) instead of 20mV (MPP for sector 7-8) operating mode automated and parallel sequencing of tests diagnostic tools and Post-Mortem more stable test data recording tools quality assurance and progress follow up learning curve for event analysis above all, the team is built and is performing well Dixit HWC project leader

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Sector 7-8: what was not done? What can we not do faster the powering for the next sectors ? Qualification of the circuits at cold (ELQA) (ELQA per DFB and no more per circuit type. Will be faster) Sequence of qualification of the QPS (FastPa and quench). Quench recovery time at high current will be a key parameter Magnet training above 11kA 350A PIC2 Injection 760A EE SPA FPA Quench 2 kA Loss PP EE Quench 6 kA 8.5 kA 12 kA RB Circuit Quench PM Analysis for each steps “No shortcut or it’ll be the Mess”

Frédérick BORDRY – LHCMAC 22- 6th December /12/ /11/2007 A V 3610A Last news from the field : Q6.R4 (MQY) powering to nominal ( pm) 3610A Unbalanced Quench Nominal Unbalanced1 Unbalanced2 Quench Nominal

Frédérick BORDRY – LHCMAC 22- 6th December 2007

Synchronisation from the database to an FGC 1.When an FGC is power-cycled or reset it raises the SYNC_FGC flag to request to be synchronised 2.The FGC Config Manager sees the request and sends commands to the FGC to read the inventory of equipment in the converter 3.The Manager sends the inventory to the database and retrieves the related configuration 4.The Manager sends commands to the FGC to update its configuration 5.The Manager clears the FGC’s synchronisation request S. Page

Frédérick BORDRY – LHCMAC 22- 6th December 2007 Synchronisation from an FGC to the database 1.A user updates the configuration in an FGC by sending the relevant commands, then sets the SYNC_DB flag 2.The FGC Config Manager sees the request and sends commands to the FGC to read the configuration 3.The Manager stores the configuration changes in the database 4.The Manager clears the FGC’s synchronisation request S. Page

Frédérick BORDRY – LHCMAC 22- 6th December 2007 RB, RQD, RQF synchronized ramp Tracking Tests RB-RQF-RQD D. Nisbet Test Method: I Channel A swapped Regulation with I Channel B