ILC Valencia Workshop November 6 – 11, 2006 DC Magnet Power Supplies

1. ILC Valencia WorkshopNovember 6 – 11, 2006DC Magnet Power Supplies Paul Bellomo – SLAC Michael Tartaglia – FNAL

2. Background and Scope • Design of magnet power systems May 2006 • Scope is DC magnet PS and associated controls for all 5 machine areas • Spreadsheet • 90,000 data input and calculations • Magnet and power supply quantities and parameters • Losses for magnets, cables and power supplies • Required AC input power • Cooling water requirements for power supplies • M & S Costs for power supplies and associated controls • Investigating costs for EDI, Assembly, R&D efforts and contingency

3. M & S Cost Summary

4. Power System - Normal T, Ind, Rack-Mounted

5. Power System - Normal T, String, Freestanding

6. Power Sys - Superconducting, Ind, Rack-Mounted

7. Cost Breakdown by Area

8. Component Cost Breakdown

9. M & S Cost Estimate Basis

10. Determining EDI and Assembly Costs PEP II and SPEAR 3 - SLAC projects include local controls, no long-haul cables or raceways or installation. Power systems costs. No superconducting magnets WQB is a FermiLab large quadrupole magnet design and fabrication project Main Injector project includes MANY things (Civil Const. and new 345kV substation, power systems, RF, controls, instrumentation – a complete accelerator)

11. Other Cost Estimates Needed • Identify Engineering/R & D items and associated costs • Redundant PS controller with EPICS IOC • Redundant PLCs and FPGA-based PACs • Redundant PS configuration • Quench and lead voltage detection and protection • Identify risk factors and contingencies

12. Magnet Power System M & S Cost Reductions • Implemented • DC power cable sized for NEC ampacity, yet large enough to keep tunnel heat loading reasonable (Damping ring exception) • Power supply rated Vo and Io as close as possible to 10% of expected operation for standardizing • Elimination of one Positron Damping Ring • BDS change 20mR-2mR to 14mR-14mR configuration • Future • Investigate smaller, less-expensive PLCs and PACs • 18,000 magnets - 13,000 power supplies. More magnets connected as strings will reduce power supply and controls quantities • Possible use of Bulk PS to power several redundant PS • Additional vendor quotes based on supplying larger quantities

13. A Look at Power Dissipations

14. Power and Losses by Area

15. Bulk PS Model Design Criteria • Why Needed • Off-line PS to magnet cable connection are expensive and heat losses excessive – new bulk PS topology needed • Advantages • Eliminate or vastly reduce 3.3MW of cable heat in tunnels • Lower cable cost • Smaller, less expensive power supplies • Disadvantages • DC-DC converters are in the tunnel • Magnet designs/styles will be constrained to operate within a limited voltage range

16. Bulk PS Model

17. Bulk PS Design Criteria • Design criteria • Busbar loop, but not closed • Busbar flat parallel plate to minimize self-inductance • Busbar is insulated to prevent shock and for prevent short circuits • Place bulk PS at loop center to minimize bus current, cross-section and voltage drop • Keep the DC-DC converter duty factor low (higher bulk to load voltage for lower busbar current) • Feed both e+ and e- rings from a common bulk PS/bus for better usage • DC-DC converters are in the beam tunnel underneath magnets • DC-DC converters have input and output common mode filters

18. The Bottom Line – Last Slide • Summarized status and basis of power system cost estimates • Complete cost estimate by end of calendar 2006 • M & S cost of present PS configuration is cost placeholder • Derive the basis for ED & I and Assembly costs • Identify and prioritize R & D costs, risk factors and develop contingency factors • Future M & S cost reductions are very promising • Continue engineering evaluation of bulk PS topology for Damping Ring PS. Consider wider use if feasible • Components are ripe for economies of larger scale • Controls technology is moving rapidly into redundancy • Possible LINAC magnet/PS quantity reductions