Accelerator Technology
Tech 11: Power Supplies
Paper Title Page
TUP061 FPC Conditioning Cart at BNL 928
 
  • W. Xu, Z. Altinbas, S.A. Belomestnykh, I. Ben-Zvi, A. Burrill, S. Deonarine, D.M. Gassner, J.P. Jamilkowski, P. Kankiya, D. Kayran, N. Laloudakis, L. Masi, G.T. McIntyre, D. Pate, D. Phillips, T. Seda, A.N. Steszyn, T.N. Tallerico, R.J. Todd, D. Weiss, A. Zaltsman
    BNL, Upton, Long Island, New York, USA
  • M.D. Cole, G.J. Whitbeck
    AES, Medford, NY, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The 703MHz superconducting gun will have 2 fundamental power couplers (FPCs). Each FPC will deliver up to 500kW of RF power. In order to prepare the couplers for high power RF service and process multipacting, the FPCs should be conditioned before they are installed in the gun. A conditioning cart based test stand, which includes a vacuum pumping system, controllable bake-out system, diagnostics, interlocks and data log system has been designed, constructed and commissioned by collaboration of BNL and AES. This paper presents FPC conditioning cart systems and summarizes the conditioning process and results.
 
 
TUP181 A Monitoring System for CSR Power Supply 1169
 
  • W. Zhang, S. An, S. Gou, W.M. Qiao, Y.P. Wang, F. Yang, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
 
  This article elaborated the monitoring system which has applied in the CSR power supply. This system is composed of the hardware and the software. The hardware is composed of PS6040-PXI-18 PXI engine case +PXI-3800 the master controller +PXI-6133 the ADC card. The software uses NI Corporation's LABVIEW to carry on the data demonstration and the analysis. This monitoring system in the CSR debugging, in the acceptance and the running has played the influential role. At the same time, it provided the data for the physical person. This monitoring system has run four years in the CSR.  
 
TUP182 In-situ System Identification for an Optimal Control of Magnet Power Supplies 1172
 
  • X.H. Ke, F. Jenni
    FHNW, Windisch, Switzerland
 
  Funding: Paul Scherrer Institute, Switzerland
In particle accelerators, the magnet power supply system (controller, power stage and magnet) normally has a higher system order (>5). An exact model, representing the behavior of such a system, would be very helpful for an optimal control. For the control, the engineers are mainly not interested in the analytic model, which shows the exact internal mechanisms of the physical system, but, in a model describing the I/O behavior. Moreover, since the real elements do not exactly correspond to the design values, it is desirable to model the power supply system by means of system identification from measured properties. For that, a subspace based identification method is applied, which yields the observer for the self-optimizing high dynamic control of magnet power supplies at the Paul Scherrer Institute (PSI). The only inputs the identification needs are the measured DC-link voltage, the magnet voltage and the magnet current. With that it calculates a corresponding state space model for the system. The whole process is done automatically and in situ, which is a practical and meaningful approach to obtain the exact system information for control design.
 
 
TUP183 Self-optimizing High Dynamic Power Supply Control 1175
 
  • X.H. Ke, F. Jenni
    FHNW, Windisch, Switzerland
  • H. Jäckle
    PSI, Villigen, Switzerland
 
  Funding: Paul Scherrer Institute, Switzerland
In 1999, the first fully digitally controlled magnet power supplies were put into operation at PSI (Paul Scherrer Institute, Switzerland). Today, approximately 1000 are in use at PSI and a multiple of that worldwide. This project aims at developing a high performance control scheme for a better dynamic behavior of today's magnet powers supplies, without reducing their excellent static behaviors. The resulting control strategy, an in situ identification based observer, combined with state space and proportional integral (SS-PI) control, leads to a significantly improved dynamic behavior of the existing power supplies. The whole commissioning, including system identification, as well as control parameter determination and optimization, is done automatically on the DSP with support of a PC. The control strategy has been implemented on the existing PSI controller and a 10A-corrector power supply, together with various magnets, by updating the software and/or firmware only. Currently, the new control strategy is being implemented and tested at PSI on a second generation Digital Power Electronic Control System (DPC) controller card.
 
 
TUP188 A New Power Supply System for the IEX Project at the APS 1178
 
  • B. Deriy, M.S. Jaski, J. Wang
    ANL, Argonne, USA
 
  A new beamline providing circularly polarized x-rays that will cover photon energies from 250 eV to 2.5 keV is under development at the APS. Because of the unique requirements of the circular polarizing undulator constructed for this beamline, a new power supply system design is required. The undulator will contain twelve sets of electromagnetic coils – two main, two quasi-periodic, and eight correctors. The undulator will incorporate variable polarization control and reduction of the magnetic fields at so-called quasi-periodic pole locations for the purpose of suppressing the higher-order radiation harmonics. The challenges met in the power supply system design for the project will be discussed.  
 
TUP190 Upgrade of the APS Booster Synchrotron Magnet Ramp 1181
 
  • C. Yao, B. Deriy, G. Feng, H. Shang, J. Wang
    ANL, Argonne, USA
 
  Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06-CH11357
The APS booster is a 7-GeV electron synchrotron with 0.5-second cycle time. Both voltage and current ramp modes were in the original design but only the voltage ramp has been commissioned. Two software-based ramp control programs are used to regulate the current waveform to a linear ramp. The system has been operated for user beam operations for many years. Some instability exists in the ramp correction that requires manual intervention from time to time by the operators. Sensitivity of magnet currents to external changes, such as AC line voltage, harmonic interference from the high-power rf system, etc., has been observed. In order to meet the increased single-bunch-charge requirement of the APS upgrade we need more flexible current ramps such as flat porches for injection and extraction and smooth transitions. Recent efforts to develop an energy-saving operation mode also call for ramp improvement. This paper presents test results of a workstation-based current regulation program and an FPGA-based implementation as a future upgrade.
 
 
TUP191 Booster Main Magnet Power Supply, Present Operation and Potential Future Upgrades 1184
 
  • E.M. Bajon, M. Bannon, G. Danowski, I. Marneris, J. Sandberg, S. Savatteri
    BNL, Upton, Long Island, New York, USA
 
  Funding: *Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, ±2000 Volts, or 3000 Amps, ±6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the different modes of operation of the power supply. Since the power supply has been in operation for the last 18 years, upgrading this power supply is essential. A new power supply topology has been studied where energy is stored in capacitor banks. DC to DC converters are used to convert the dc voltage stored in the capacitor banks to pulsed DC voltage into the magnet load. This enables the average incoming power from the ac line to be constant while the peak magnet power is pulsed to ± 18 MWatts. Simulations and waveforms of this power supply will be presented.
 
 
TUP193 NSLS-II Power Supply Controller 1187
 
  • W. Louie, L.R. Dalesio, G. Ganetis, Y. Tian
    BNL, Upton, Long Island, New York, USA
 
  This paper presents the design of the National Synchrotron Light Source II (NSLS-II) Power Supply Controller (PSC). It consists of a main board, rear module and backplane. The main features of NSLS-II PSC included 256MB DDR2 memory for power supply system diagnostics, high speed serial link between PSC modules, an embedded microprocessor and a 100 Mbps Ethernet port. Each PSC module can be remotely programmed through network. NSLS-II PSC will be used to control power supplies in Storage Ring, Booster Ring and Transport line. The PSC also provides interface for the NSLS-II fast and slow orbits feedback system.  
 
TUP195 Commissioning the ALS Digital Power Supply Controller in the Booster Dipole and Quadrupole Magnet Power Supplies 1190
 
  • J.M. Weber, T. Scarvie, C. Steier, CA. Timossi
    LBNL, Berkeley, California, USA
 
  Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) is a third generation synchrotron light source that has been operating since 1993 at Berkeley Lab. A few years ago, the ALS was upgraded to achieve Top-Off Mode, which required replacing the booster dipole and quadrupole magnet power supplies to increase the peak booster beam energy from 1.5GeV to 1.9GeV. The original analog controller for each power supply has been replaced by a digital power supply controller (DPSC) to improve stability and resolution and provide a remote interface. The DPSC capabilities include 24-bit 100k-point digital reference waveform download and voltage reference generation, and complete digital current loop implementation. The hardware includes an FPGA with an embedded processor running a full EPICS IOC on VxWorks. This paper will present the current functionality of the DPSC as well as performance results from recent commissioning.

 
 
TUP196 SLAC P2 MARX Control System and Regulation Scheme 1193
 
  • D.J. MacNair, M.A. Kemp, K.J.P. Macken, M.N. Nguyen, J.J. Olsen
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515
The SLAC P2 MARX P2 Modulator consists of 32 cells charged in parallel by a -4000V supply and discharged in series to provide a -120 KV 140 amp 1.6 millisecond pulse. Each cell has a 350uF main storage capacitor. The voltage on the capacitor will droop approximately 640 volts during each pulse. Each cell will have a boost supply that can add up to 700V to the cell output. This allows the output voltage of the cell to remain constant within 0.1% during the pulse. The modulator output voltage control is determined by the -4KV charging voltage. A voltage divider will measure the modulator voltage on each pulse. The charging voltage will be adjusted by the data from previous pulses to provide the desired output. The boost supply in each cell consists of a 700V buck regulator in series with the main capacitor. The supply uses a lookup table for PWM control. The lookup table is calculated from previous pulse data to provide a constant cell output. The paper will describe the modulator and cell regulation used by the MARX modulator. Measured data from a single cell and three cell string will be included.