1. HA Power Supplies - Demonstration Criteria and Status February 23, 20061 ATF2 Project HA Power Supplies Demonstration System Evaluation Criteria And Status as of February 23, 2006 Paul Bellomo and Briant Lam

2. HA Power Supplies - Demonstration Criteria and Status February 23, 20062 Demonstration Criteria Build a power system with Ethernet control that will provide 150A in a 3 out 4 redundant module configuration. Demonstrate performance, redundancy and current sharing

3. HA Power Supplies - Demonstration Criteria and Status February 23, 20063 Rack and Power System Layouts

4. HA Power Supplies - Demonstration Criteria and Status February 23, 20064 System Block Diagram Note that the demonstration system might not include all the elements shown in this block diagram

5. HA Power Supplies - Demonstration Criteria and Status February 23, 20065 Availability Improvement By Oversizing and Redundancy

6. HA Power Supplies - Demonstration Criteria and Status February 23, 20066 Test Parameters and Success Criteria Evaluated ParameterSuccess Criteria Rated load current from redundant configuration 150A regulated output from either 4 modules or 3 modules Load current sharing ≤ 5% current mismatch from 3 or 4 modules at 100% and 25% rated output Redundancy Loss of one module, system recovers current within 1 millisecond Current stability versus time and temperature ≤ 3 ppm drift in 10 minutes, monitor  ≤ 10 ppm drift in 8 hours, monitor  Bandwidth≥ 10Hz by Bode plot Ethernet controlNew Ethernet controller

7. HA Power Supplies - Demonstration Criteria and Status February 23, 20067 Status as February 23, 2006 Presently operating and evaluating five parallel-connected power modules under closed loop control under BitBus control Operating with phase-shifted input PWM signals to increase effective switching frequency and reduce output ripple. Operating to a combined 100A of load current while monitoring individual power module output current and output ripple voltage. Observed nicely balanced currents in the power modules. Correlated load current sharing to the precision of match among the five phase- shifted PWM signals. Simulated a failure of one power module by disabling the PWM signal to one power module during five power module operation to 100A,. Observed a re- distribution of load current among the remaining four operating power modules. This indicates that the redundancy scheme is feasible. Confirmed the expected increase in output voltage ripple when one power module is disabled. The demonstration system is on a correct technical path, it is on budget and it is on schedule

8. HA Power Supplies - Demonstration Criteria and Status February 23, 20068 The System

9. HA Power Supplies - Demonstration Criteria and Status February 23, 20069 Operating Power Supplies

10. HA Power Supplies - Demonstration Criteria and Status February 23, 200610 The Power Modules

11. HA Power Supplies - Demonstration Criteria and Status February 23, 200611 Near-Term Next Steps 1.Operate four power modules in a three-out-of-four redundant configuration connected to an inductive load to provide a combined output of 150A. Upon the loss of one module the remaining three will each operate at their rated output of 50A. Monitor the transient current re- distribution among the power modules under these conditions. 2.Place four power modules into an environmentally-controlled temperature chamber (refer to the next slide). Connect them to an inductive load. Test the load current stability and power module current sharing versus time and temperature of the three-out-of-four configuration. 3.Upgrade the BitBus controller to an Ethernet controller

12. HA Power Supplies - Demonstration Criteria and Status February 23, 200612 Environmental Test Chamber

13. HA Power Supplies - Demonstration Criteria and Status February 23, 200613 End Slide - Development Workaround During Decision Period Workaround during decision phase Item 3 critical path – Interface with KEK to specify the controls, performance/features of the power modules and their crates