1. Internal review of superconductor and magnet laboratories1 Status of LHC-TB Power Converters Hugues Thiesen TE-EPC

2. 2 Contents  Inventory of power converters  Status of power converters  AC and CV infrastructures  Client requests  Conclusions and recommendations Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

3. 3 Inventory of power converters  Power converters have been designed for LHC applications High current (up to 15 kA) and Low voltage (6V to 16V) Main PCs are unipolar in current and Corrector PCs are limited to 600A  40 power converters in 8 different laboratories 4 in Block-4 for diode packs and special magnets  1 x [15kA/25V] thyristor power converter (20kA)  2 x [±600A/±12V] switch mode power converters (CIRTEM)  1 x [±2kA/±10V] modified LEP type D power converter 5 in building 163 for superconducting cables  3 x [16kA/6V] switch mode power converters (Danfysik)  1 x [4kA/8V] switch mode power converter (Kempower)  1 x 1Q with mechanical polarity switch (ISR power converter) 1 in building 180 for Atlas (Out of Service since 2006)  1 x [24kA/6V] switch mode power converters (Danfysik) 1 in building 281 for 600A HTS current leads  1 x [±600A/±12V] switch mode power converters (Transtechnik) Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

4. 4 Inventory of power converters  40 power converters in 8 different laboratories (cont.) 1 in SM-18 for RF cavities  1 x [100kV/40A] LEP RF power converter 2 in SM-18 for calibration of magnetic instrumentation  1 x [200A/300V] LEP type B power converter  1 x [±600A/±12V] switch mode power converter (Transtechnik) 1 in SM-18 for 13 kA current leads (Out of Service since 2004)  1 x [15kA/16V] switch mode power converters (Transtechnik) 26 in SM-18 for MQ and MB magnets  1 x [15kA/±70V] thyristor power converter (20kA)  5 x [15kA/±16V] thyristor power converter  6 x [±600A/±12V] switch mode power converter (Transtechnik)  6 x [±600A/±12V] switch mode power converter (CIRTEM)  4 x [±60A/±8V] switch mode power converter (LHC prototype)  2 x [±60A/±8V] switch mode power converter (LHC series)  2 x [±120A/±10V] switch mode power converters (LHC series) Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

5. 5 Status of power converters  Status of power converters 14 different types of power converters Between 10 and 20 years old Prototype PCs or modified PCs  Main issues Number of spare parts is limited  No spare parts for the [±2kA/±10V] power converter in Block-4  No spare parts for the 18kV transformer (special transformer with 2 outputs) used for the [15kA/±70V] power converter in SM-18 (cluster A) Obsolescence of the components  Power semiconductors  Digital electronics End of the lifetime for several devices  MCB for the [15kA/±16V] power converters (MTB in SM18) Difficulties to modify the power converters  It is not possible to modify the internal software for several PCs (LEP)  It is difficult to modify the software of the MTB PCs Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

6. 6 AC and Water infrastructures  AC infrastructure No problem with the existing AC infrastructures if no additional power converters are requested  The AC infrastructures have been designed for the initial requests only 1 x (2MVA, 400V) switch-board free in SM-18 (String II)  Possibility to install the Block-4 power converters in SM-18  Cooling infrastructure In general, no problem with the existing cooling infrastructures if no additional power converters are requested Limited capacity in SM-18  No possibility of using the 6 MTBs at the same time (max. 3)  Water cooling problem if the Block-4 power converters are installed in SM-18 Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

7. 7 Analysis of client requests  LHC spares and stock No major problem (limited activity) Main issues  The diode packs can be tested only in Block-4 with the [15kA-25V] power converter (special test bench)  The 15kA power converter of the CL test bench is not operational  LHC operation support No major problem (limited activity)  LHC upgrade phase I Main issues  For this moment the corrector power converters are limited to 600A ([±600A/±12V])  The needs for the string test must be defined  Development requests The requests must be clearly defined  Specifications (maximum current and voltage, accuracy, etc…)  Types of power converters (1Q, 2Q, etc…) Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters

8. 8 Conclusions and recommendations  Conclusions and recommendations The LHC TB power converters have been designed for LHC (max. current is 15 kA). 20kA can be reached in SM-18 (Cluster A) but new DCCTs must be bought. The [24kA/6V] power converter in building 180 and the [15kA/16V] power converter in SM-18 are not operational. The 24kA can be restart but the 15kA must be replaced. The [±2kA/±10V] power converter in Block-4 is at the end of its lifetime and must be replaced. The ISR power converter in building 163 is obsolete and must be replaced. 4 of the 6 [±60A/±8V] power converters in SM-18 are prototype power converters. The replacement of these 4 power converters by LHC power converters (750 in operation) is strongly recommended. All software modifications are difficult or impossible. The replacement of the control electronics (FGC-1) of the SM-18 power converters by LHC control electronics (FGC-2) is strongly recommended. No problem to support a limited activity. If the activity must increase, a PC consolidation must be planed (e.g. MCB of the main PC of the MTB in SM-18) Internal review of superconductor and magnet laboratories - Status of LHC-TB Power Converters