1. Status of the models of the LHC superconducting circuits (2009-2015) (Pspice, QSF-Simulink) Emmanuele Ravaioli Thanks to E. Antonopoulou, S. Rowan, M.A. Dominguez Martinez, D. Egede Rasmussen, K.A. Sperin, M. Maciejewski, J. Blomberg Ghini, B. Auchmann, and A. Verweij LHC-CM 12-03-2015

2. Status of the electrical models of the LHC superconducting circuits 2 MainSub-class#magnetsI_ultim [A]#PCPC typeEE R_par Magnet typePspiceQSF (Simulink) RB 154130001113kA X MBXX* RQRQD/RQF47-51130001213kA X MQX RQX 471803 MQXA/MQXBX IPDRD1/2/3/41-24670-66501 MBX/MBRC/ MBRS/MBRB X IPQRQ4/5/6/7/8/9/102-43900-58202 MQY/MQM MQMC/MQML XX 600 ARCD76-77600110 600A MCD 600 ARCS153-154600110 600A X MCS 600 AROD/ROF8-13600110 600A MO 600 ARQ66490110 600A X MQTLH 600 ARQS2-4600111 600A X MQSX 600 ARQT12/131600111 X MQT 600 ARQTD/RQTF8600110 600A X MQT 600 ARQTL7/8/9/10/111600111 X MQTLIX 600 ARSD/RSF9-12600110 600A X MS 600 ARSS4600110 600A X MSS 600 A RCBXH/RCBXV /RQSX3/RU 1600110MCBXH 80-120 ARCO77110115MCO 80-120 ARCBYH177115MCBYH X* 80-120 ARCBCH, etc1110115 X MCBCH Models of all main circuit components available in PSpice 8oo8 2oo23oo3 E. Ravaioli LHC-CM12-03-2015 !

3. You get what you give… 3 Energy-extraction switches (EE) Power converter (PC) Magnets (differential inductance, strand/cable parameters, magnetic field, coupling loss, quench propagation, etc) 2-nd order elements (parasitic capacitances, inductance of warm leads, grounding lines, etc) Electro-dynamic (Electrical circuit modeling) Quench performance Quench performance in a complex circuit E. Ravaioli LHC-CM12-03-2015 Circuit topology Simple transient analysis

4. Models of EE switches 4 Functions reproducing EE opening available for both 13 kA and 600 A switches Each switch is modeled by four switches in series to model the different phases of the switch opening. 2-nd order elements added (ex: inductance of the warm leads) E. Ravaioli LHC-CM12-03-2015

5. Sample results – 600 A EE switch opening 5 E. Ravaioli LHC-CM12-03-2015 Thanks to Evelina Antonopoulou

6. Models of PC’s 6 4 main types of power converters enough to simulate most circuits 1.Simple power converter (ex: RPHH in RQ4) 2.Power converter with filter (ex: RPTE in RB) 3.Modular power converter (ex: RPHE in RQD/RQF) 4.Voltage-controlled power converter (ex: RPLB in RCBY) E. Ravaioli LHC-CM12-03-2015

7. 1. Simple power converter (RPHH in RQ4) 7 Power Converter Grounding point 20x free-wheel Diodes Power converter modeled simply as an ideal current source Power converter by-passed by 20 free-wheel diodes which allow the flow of the current after the shut-down of the PC E. Ravaioli LHC-CM12-03-2015

8. 2. Power converter with output filter (RPTE in RB) E. Ravaioli LHC-CM12-03-2015 8 Power Converter + 2 Thyristors Grounding point Filter Capacitors PC composed of two parallel units 6x Crowbars to allow by-pass of the PC at the shut-down (Thyristor model needed) Filter at the output of the PC PC grounded in the positive and negative branches through capacitors Resistance and inductance of PC cables taken into account (rule of thumb for L: 1 μH  1 μ  ) Grounding point Filter Inductors Power Converter + 2 Thyristors 6x Crowbars with Thyristors

9. 2. Power converter with output filter (RPTE in RB) – Sample results E. Ravaioli PSpice Simulations - RB circuit - S67 February 2015 9 ADDITION OF 4x (THY+4 Uh) in //, BIPOLAR, + RS=72 mΩ 2010-2011 CONFIGURATION E. Ravaioli LHC-CM12-03-2015

10. 3. Modular power converter (RPHE in RQD/RQF)-a 10 5 // 3 // 4 = 60 PC modules in parallel (see next slide) + 5 // 3 = 15 output filters 3 paths for the current after the shut-down 64 Schottky diodes (90% of the current) 120 Schottky diodes (10% of the current) 3 disc diodes (no current, redundant) E. Ravaioli LHC-CM12-03-2015

11. 3. Modular power converter (RPHE in RQD/RQF)-b 11 Each PC module is modeled by an ABM (Analog Behavior Modeling) current source t <= t_shut-down:I_circuit = I_input t > t_shut-down:I_circuit = V(D1-D0)/10μ  The PC becomes a short-circuit E. Ravaioli LHC-CM12-03-2015

12. 4. Voltage-controlled power converter (RPLB in RCBY) 12 In order to simulate the discrete behavior of the electronics controlling the voltage across the PC, a new approach is followed. The PC is simulated by a voltage-controlled voltage source, whose reference value is updated discretely (in the example, every 80 ms). The reference values of the voltage and current of the real PC are calculated by ABM components ruled by functions similar to those used by the PC electronics. every Dt:I_ref = I_input V_ref = L_circuit * ( I_ref – I_meas ) / Dt + R_circuit * I_ref ) Input current (continuous curve) Calculated reference current (updated every 80 ms) Imposed voltage (updated every 80 ms) Calculated reference voltage (updated every 80 ms) Real PC Fake PC E. Ravaioli LHC-CM12-03-2015

13. Grounding 13 E. Ravaioli LHC-CM12-03-2015 RB chain Main ground point Multiple parallel branches with different purposes RB chain Local grounds Grounds of physically adjacent magnets connected by low resistances

14. Models of magnets 14 Different level of complexity (and CPU time) Magnet = Simple inductor Electro-dynamic inductor (<10 lumped-elements: main inductance, parasitic capacitance, 1st order frequency transfer function) Inductor + (very!) simplified thermal model (1-4 bulk temperatures) Full 2D electro-magnetic and thermal model (differential inductance, strand/cable parameters, magnetic field, coupling loss, quench propagation, etc) E. Ravaioli LHC-CM12-03-2015

15. Sample results – Electro-dynamic inductors 15 E. Ravaioli LHC-CM12-03-2015 Magnet 001  Blue Magnet 154  Red RB chain Fast power abort

16. Sample results – (very!) Simplified thermal models of magnets 16 RQ4.L8 Heater-induced quench in a nested circuit (2 PC’s, 2 coils, 3 leads) E. Ravaioli LHC-CM12-03-2015

17. Sample results – Full 2D electro-magnetic and thermal model 17 E. Ravaioli LHC-CM12-03-2015 MQXF CLIQ discharge

18. Coupled electro-dynamic chain & 2D electro-thermal magnet model 18 E. Ravaioli LHC-CM12-03-2015

19. QSF (Quench Simulation Framework) in Simulink/Matlab 19 E. Ravaioli LHC-CM12-03-2015 Same features of the Spice models (validated), with much more… Automatic generation of models (much faster, less mistakes, more components) 3-level architecture, Object-oriented programming Possible to use the framework without GUI Possible to re-use the developed Simulink models without the framework Possible to use the same methodology to export components to other software (in the future) Automatic run of simulations Integrated post-processing GUI Libraries of magnet models, cables, strands, materials

20. Complete 2D electro-thermal models of magnets 20 When detailed magnet model is available, quench performance simulations are possible: Coupling loss calculation (Quench-back, differential inductance vs dI/dt) CLIQ QH (soon fixed) Integration of a full electro-thermal model of a magnet in a chain (MB in RB chain, done*) E. Ravaioli LHC-CM12-03-2015 MagnetPSpiceQSF (Simulink)Measurements MQXC2X*XX HQ02 XX SQXF X soon MQXF X MB X soon MQY X soon 11 T Dipole X HD2/3 X D1 X

21. How much time does it take for…? 21 E. Ravaioli LHC-CM12-03-2015 ActionTime Adapt one Pspice model of a circuit type to a specific circuit<1 day Learn PSpice + tricks1 month Develop new "simple" LHC circuit type with PSpice1 week Develop new 2D magnet model with PSpice1 month Learn QSF (GUI)1-2 days Develop new "simple" LHC circuit type with QSF1 week Develop new 2D magnet model with QSF1 week Migrate EE models from PSpice to QSF1-2 days Migrate complex PC models from PSpice to QSF2 weeks Migrate and validate one "simple" LHC circuit type (RQX, IPQ/IPD, RQS, RQTL, etc) 1 week/c (5-10 circuits) Migrate one simple LHC circuit + develop corresponding 2D magnet model 1+1 week/c (5-10 circuits) Migrate RB chain (only manually)1 morning? ;-) Validate RB migration2 weeks Rerun RB fault-case analyses2 weeks Migrate and validate RQD/RQF chain2 weeks?

22. Conclusion/Scenarios 22 E. Ravaioli LHC-CM12-03-2015 Scenario 1Scenario 2Scenario 3 Maintain all Pspice models; QSF only for quench performance Migrate PSpice models to QSF Migrate PSpice models to QSF and develop 2D magnet models Rapid response to LHC-related analysis requests must remain assured at any time ProsNo time spent in migration One tool to learn; Faster development of new circuits; One tool to learn; Faster development of new circuits; Quench-back analysis; Support for CLIQ-integrated circuits; Cons 1-2 months learning time; 2 simulation tools to learn/maintain; 2-3 months migration time; Loss of PSpice expertise; 4-6 months migration time; Loss of PSpice expertise;

23. Annex 23 E. Ravaioli LHC-CM12-03-2015

24. Sources of information about the power converter General presentation about the PCs installed in the circuits, useful documents, simplified schematic of the circuits http://te-epc-lpc.web.cern.ch/te-epc-lpc/general.stm Numeric information about the PC parameters in the LHC equipment catalogue (nominal values) and in the LHC layout database (as-built values) (range of V and I, R_crowbar, modules) http://layout.web.cern.ch/layout/ (example)http://layout.web.cern.ch/layout/ https://edms.cern.ch/nav/P:LHCPM011:V0/I:LHCABS001460:V0 (example)https://edms.cern.ch/nav/P:LHCPM011:V0/I:LHCABS001460:V0 Contact the persons responsible for the PC Yves Thurel Hugues Thiesen Valerie Montabonnet …etc Electrical drawing of the PC (further details about the components, types of diodes and thyristors, paths to ground, modules, …) Datasheets of the installed diodes, thyristors, etc 24 E. Ravaioli LHC-CM12-03-2015

25. Simple power converter (RPHH in RQ4)-2 PC modeled by a current source In Pspice, use an istm component: the current is ruled by an input file which can be modified using Stimulus Editor (within the Cadence suite) or manually editing the.stl (or.ctl) file with NotePad (preferred). Such a file can be found in the folder of the PSpice project. Example: \\cern.ch\dfs\Services\cdsusers\eravaiol\RB_A12_PROJECT\worklib\rb_a12_design\psp_sim_1\profiles\transient \\cern.ch\dfs\Services\cdsusers\eravaiol\RB_A12_PROJECT\worklib\rb_a12_design\psp_sim_1\profiles\transient 25.STIMULUS RAMP_2K_0AS PWL + TIME_SCALE_FACTOR = 1 + VALUE_SCALE_FACTOR = 1 + ( 0.000, 0) + ( 407.71, 0) + ( 607.71, 2000) + ( 657.71, 2000) + ( 657.72, 0) + ( 1K, 0) E. Ravaioli LHC-CM12-03-2015

26. Simple power converter (RPHH in RQ4)-3 Model of the diode 245NQ015(R) The PSpice parameters depend on the type of diode/thyristor, on the type of junction, on the operating temperature and on the key parameters present in the datasheet. Example Note: Not all the PSpice parameters are mandatory for a good modeling. Useful links: http://www.allaboutcircuits.com/vol_3/chpt_3/14.html http://www.ece.uci.edu/eceware/ads_docs/ccnld/ccnld019.html 26 NameMinMaxDefaultValue IS1.00E-200.11.00E-140.000127 N0.2512 RS1.00E-061000.001 IKF0100000 XTI-10010032 EG0.15.511.110.69 CJO1.00E-200.0011.00E-126.00E-09 M0.1100.33330.48 VJ0.3905100.750.6 FC0.001100.5 ISR1.00E-200.11.00E-10 NR0.5522 BV0.11000000100150 IBV1.00E-09100.00010.006 TT1.00E-160.0015.00E-095E-09 E. Ravaioli LHC-CM12-03-2015

27. PSpice tips & tricks about power converters Pay attention: a current source is very powerful! If you put a current source in your model, the current in this branch WILL be the one you set. Example: If you set a PC input current which doesn’t go to zero before the opening of an extraction resistor, you build up a huge voltage across the PC, because the current source will force the current through the resistor! You cannot put two current source in series: PSpice would try to force two different currents in the same branch. If you need to put them in series anyway, you can put a fake 1 GOhm resistor in parallel to one of them. This is formally allowed, and won’t change the results. You cannot put two capacitors in series, or a capacitor in a branch which goes directly to the ground of the circuit. Again, you’ll need to use fake 1 GOhm resistors in parallel to the capacitors. Use your fantasy: The same PC can be modeled by means of a current source, a voltage-controlled voltage source, a current source which becomes a short-circuit, etc… With the ABM components you can model anything you need! 27 E. Ravaioli LHC-CM12-03-2015