07 Accelerator Technology

T11 Power Supplies

Paper Title Page
WEPLS117 The Australian Synchrotron Storage Ring Dipole Power Supply 0
 
  • N.J. Meadowcroft, R. Farnsworth
    ASP, Clayton, Victoria
  • P. Bellomo
    SLAC, Menlo Park, California
  • S. Cohen
    LANL, Los Alamos, New Mexico
  • R. Rumrill
    Alpha Scientific Electronics, Hayward, California
  
  The Australian Synchrotron storage ring consists of 28 dipoles, 56 focusing quadrupoles, 28 defocusing quadrupoles, 98 sextupoles, 42 horizontal correctors, 56 vertical correctors and 28 skew quadrupole correctors. The 28 dipole magnets are series connected and powered by a single 1100V, 850A, 24 pulse power supply with an output stability better than 100ppm. The paper will discuss the design, testing, commissioning and control interfaces for the storage ring dipole power supply.  
WEPLS118 The 3Hz Power Supplies of the SOLEIL Booster 2652
 
  • P. Gros, S. Bobault, A. Loulergue
    SOLEIL, Gif-sur-Yvette
  
  SOLEIL is a 2.75 GeV new third generation synchrotron radiation facility under construction near Paris. The injector system is composed of a 100 MeV electron Linac pre-accelerator followed by a full energy (2.75 GeV) booster synchrotron. A repetition rate of 3Hz is required for the booster for the filling of the Storage Ring together with the need for discontinuous operation for top-up filling mode. Based on digital regulation loop, the four power supplies (2 for the dipoles 600 A x 1000 V and 2 for the quadrupoles 250 A x 450 V) reach the current tracking tolerance specification of 10-3. The aim of this paper is to describe the main issues from the loads to the mains network through the power converters that are essential to reach the required performances.  
WEPLS119 Power Converters for the ISIS Second Target Station Project (TS-2) 2655
 
  • S.L. Birch, A. Morris, S.P. Stoneham
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  
  The Extract Proton Beamline to the ISIS second target station will require magnets to be powered by ac/dc power converters. A total of 50 magnets, quadrupole and dipole, require high stability dc current converters over a large dynamic range from several kW to 600kW. There is also a requirement for two 10Hz pulsed magnets to extract the proton beam from the present 50Hz target beamline, and hence specially designed power supplies are necessary. This paper describes the selection process, types of topology considerations and final selections.  
WEPLS122 Multiphase Resonant Power Converter for High Energy Physics Applications 2658
 
  • M.J. Bland, J. Clare, P. W. Wheeler
    University of Nottingham, Nottingham
  
  Accelerators used for experiments in high-energy physics require very high power radio frequency sources to provide the energy needed to accelerate the particles. The RF power needs to be stable and predictable such that any variation in the supplied RF power has a limited and acceptable impact on the accelerated beam quality. This paper considers the design of a "long-pulse" modulator supply rated at 25kV, 10A (250kW peak power, duty ratio 10%, 25kW average power, pulse length ≈ 1 − 2ms). The supply is based on direct modulation of a multi-phase resonant power supply, fed by an active rectifier. The objectives of the development are to produce a compact power supply, with low stored energy and with high power quality at the utility supply. The paper provides a brief overview of the technology, followed by a discussion of the design choices. Initial results from the laboratory prototype will be included.  
WEPLS123 Initial Experimental Results of a New Direct Converter for High Energy Physics Applications 2661
 
  • D. Cook, M. Catucci, J. Clare, P. W. Wheeler
    University of Nottingham, Nottingham
  • C. Oates
    Areva T&D, Stafford
  • J.S. Przybyla, R. Richardson
    e2v Technologies, Essex
  
  This paper presents practical results for a new type of power supply for high energy physics CW applications. The converter is a direct topology operating with a high frequency (resonant) link. Losses are minimised by switching at zero current. High operating frequency reduces the filter and transformer size. The transformer uses the latest nano-crystalline materials to further reduce losses. Where possible, circuit elements are incorporated into the transformer to reduce the physical size of the converter. Design of this transformer to accommodate the insulation, VA rating and circuit elements is non-trivial. The Radio Frequency power generated is stable and predictable, whilst the reduced energy storage in filter components removes the need for crowbar circuits. Potential benefits of this converter when compared to conventional approaches are discussed. These include reduced energy storage, reduced turn-on time and enhanced energy density when compared with existing topologies. Preliminary practical results are promising and are presented along with simulation results.  
WEPLS124 Diamond Booster Magnet Power Converters 2664
 
  • J.A. Dobbing, C.A. Abraham, R.J. Rushton
    Diamond, Oxfordshire
  • F. Cagnolati, M.P.C. Pretelli, L. Sita
    O.C.E.M. S.p.A., Bologna
  • G. Facchini
    CERN, Geneva
  • C. Rossi
    CASY, Bologna
  
  This paper will describe the design, factory tests, commissioning and early operation of the Diamond Booster Power Converters. The Power Converters covered are the Dipole, Quadrupole with two outputs, two bi-polar Sextupoles and 44 Steerers. The actual achieved performance will be compared with the specification and the extensive modelling that was carried out during the design phase. The design includes measures to enhance the reliability of the power converters, such as redundancy, plug-in modularity, component de-rating and component standardisation. All the Diamond power converters use the same digital controller, manufactured under licence from the Paul Scherrer Institute.  
WEPLS125 Diamond Storage Ring Magnet Power Converters 2667
 
  • R.J. Rushton, C.A. Abraham, J.A. Dobbing
    Diamond, Oxfordshire
  • F. Cagnolati, G. Facchini, M.P.C. Pretelli, V.R. Rossi, L. Sita
    O.C.E.M. S.p.A., Bologna
  • C. Rossi
    CASY, Bologna
  
  The DC Magnet Power Converter requirements for the Storage Ring of the Diamond Project are described together with performance, commissioning and initial operating experience. In addition to meeting the required performance, emphasis during the design phase was placed on reliability and minimising the mean time to repair a power converter. A modular design, built-in redundancy, EMC filtering and testing, component de-rating and standardisation have all been adopted. The power modules for the 200A supplies were subject to highly accelerated stress screening. All converters are switched mode with full digital control and a common control interface. Every power converter appears identical to the Controls Network, from the lowest power corrector up to the 800 kW Storage Ring Dipole Converter.  
WEPLS126 CNAO Resonance Sextupole Magnet Power Converters 2670
 
  • M.F. Farioli, F. Burini, S. Carrozza, M. Cavazza, S. Minisgallo, M.P.C. Pretelli, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • D. Bagnara, M. Spera, A. Tilli, M. Toniato
    CASY, Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  
  The CNAO Resonance Sextupole Magnet Power Converter requirements for the Storage Ring of the CNAO Project are described together with performance and initial operating experience. In particular the achieved performances will be compared with the specification and the extensive modelling that was done during the design phase. Not only the tight required performances were emphasized during the design phase but also particular attention was put on reliability and minimization of the repairing time (MTTR). Some fundamental criteria, like component de-rating and standardisation, have also been taken into account during the component choice phase. All converters adopt the switching technology with full digital control and a common control interface, that, as for the other CNAO power converters, uses the same digital controller, under licence from the Diamond Light Source.  
WEPLS127 CNAO Storage Ring Dipole Magnet Power Converter 3000A / ±1600V 2673
 
  • M.P.C. Pretelli, F. Burini, S. Carrozza, M. Cavazza, M.F. Farioli, S. Minisgallo, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  • F. Ronchi, C. Rossi, M. Spera, M. Toniato
    CASY, Bologna
  
  This paper will describe the design and simulations of the CNAO Dipole Power Converter rated 3000A / ±1600V. The Power Converter will feed the 16+1 synchrotron bending dipole magnets of the CNAO Storage Ring. The actual design confirms how the choice of a 24-pulses, 4 bridges series-parallel connected, active filter, bipolar voltage, meets the stringent requested technical specification ( 10-5 of maximum current for the output current residual ripple and setting resolution). The extensive modelling will also be presented. The design includes the strength of the topology design, component de-rating and component standardisation. As the other CNAO power converters, the Storage Ring Dipole Power Converter uses the same digital controller, under licence from the Diamond Light Source.  
WEPLS128 The Italian Hadrontherapy Center (CNAO): A Review of the Power Supply System for Conventional Magnets 2676
 
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  • L. Balbo, N. Balbo, A. Tescari
    EEI, Vicenza
  • F. Burini, S. Carrozza, M. Cavazza, M.F. Farioli, S. Minisgallo, M.P.C. Pretelli, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  
  A hadron (Carbon/Proton) medical centre based on a synchrotron accelerator dedicated to the cure of deep tumours is under construction in Pavia (Italy) under the joint responsibility of CNAO (Centro Nazionale di Adroterapia Oncologica) and INFN (Istituto Nazionale di Fisica Nucleare). This paper describes the power supply system, made up of about 200 units designed by LNF, and whose converters for the synchrotron ring and related low, medium and high energy transfer lines are now under construction by the major Italian companies. The power supplies requirements and electrical characteristics will be reported describing the most interesting topologies that fulfill the requested performances together with the main features of each power supply topology. Synchrotron dipoles, quadrupoles, sextupoles and resonance sextupole power supplies have tight characteristics with respect to precision class (current resolution, residual ripple, short-long term stability, etc.) that range from 5 ppm to 500 ppm, fast dynamical response with bandwidth up to some hundreds hertz, high power from tens of kW to many MW and output current ranging from hundreds of A to 3 kA.  
WEPLS129 Upgrade Scheme for the J-PARC Main Ring Magnet Power Supply 2679
 
  • H. Sato, K. Koseki, K.O. Okamura, t.s. Shintomi
    KEK, Ibaraki
  
  Japan Proton Accelerator Research Complex (J-PARC) is under construction at the Tokai campus of Japan Atomic Energy Agency (JAEA) as a joint project between KEK and JAEA. The accelerator complex, which is constructed as a 200 MeV linac, a 3 GeV RCS synchrotron, and a main ring in phase I. The main ring magnet power supply is constructing as the energy of 40 GeV in phase I and will upgrade up to 50 GeV in phase II. A large amount of pulse electric power, which is + 115 MW and -55 MW peak-to-peak, is required for 50 GeV operation and this large pulse power will give unallowable disturbances to a power network. In order to compensate the disturbances to allowable level, we need some energy storage system. A SMES system will be one of the promising means for the purposes as well as the fly-wheel system. We will describe some energy storage system and also the increasing of repetition rate without energy storage system.  
WEPLS131 Programmable Power Supply for Distribution Magnet for 20-MeV PEFP Proton Linac 2682
 
  • S.-H. Jeong, J. Choi, H.-S. Kang, D.E. Kim, K.-H. Park
    PAL, Pohang, Kyungbuk
  
  The distribution magnet is powered by bipolar switching-mode converter that is employed IGBT module and has controlled by a DSP (Digital Signal Process). This power supply is operated at 350A, 5 Hz programmable stair output for beam distribution to 5 beamlines of 20-MeV PEFP proton linac. Various applications for the different power supply are made simple by software. This paper describes the design and test results of the power supply.  
WEPLS132 New Magnet Power Supply for PAL Linac 2685
 
  • S.-C. Kim, J. Choi, K.M. Ha, J.Y. Huang, J.H. Kim, S.H. Kim, I.S. Ko, S.S. Park
    PAL, Pohang, Kyungbuk
  
  Since the completion of PLS in 1994, PLS Linac magnet power supply(MPS) has been operated for 12 years with 12-bit resolution and 0.1% stability. Improvement in the resolution and the reliability of the Linac MPS is highly required now for the stable beam injection and 4th generation light source research. To improve MPS, we developed new compact MPS of 16-bit resolution and 20ppm stability using four-quadrant switching scheme with 50kHz MOSFET switching device. Bipolar MPS for corrector magnet consists of main power board, control power board, regulator board and CPU board. Size of each board is only 100mm width and 240mm depth. Unipolar MPS for quadrupoles and solenoid magnets is composed by parallel-operation of two main power boards, doubling the current output. Output of MPS is 10V, ±10A for the bipolar and 50V, 50A for the unipolar magnet. In this paper, we report on the development and characteristics of the new MPS for PAL linac.  
WEPLS133 Stability Study of Superconductor Magnet Power Supplies at TLS 2688
 
  • Y.-C. Chien, K.-T. Hsu, C.-S. Hwang, C.-Y. Liu, K.-B. Liu
    NSRRC, Hsinchu
  
  In this paper, performance of three power supplies schemes driving the newly-developed Superconducting Wave Length Shifter Magnet at TLS is investigated. Due to the inherent structure of the Superconducting Magnet, the main and two accessory trimming power supplies are physically correlated with each others. Due to the inherent structure, in order to achieve high performance control of the magnet, slew rate control of the main power supply and the proper operation sequence have to be properly managed, otherwise, small current disturbance can occurs, which may disgrade the stability of the performance of Superconducting Magnet.  
WEPLS134 Design and Modeling of the Step Down Piezo Transformer 2691
 
  • C.-Y. Liu, Y.-C. Chien, K.-B. Liu
    NSRRC, Hsinchu
  
  The energy conversion and the step down voltage waveform of the piezo transformer are required to achieve optimal working condition of the resonate frequency. To meet this requirement, a reliable and precise instrument is needed to scan the resonated point of the piezo transformer such that the piezo transformer's output performance can meet required specification. In this paper, design and modeling of a new step down piezo transformer deployed in NSRRC is described. This step down piezo transformer is capable of delivering energy conversion with high efficiency performance, which is better than traditional transformer, and the voltage transfer ratio is correct. The simulation circuit model used to develop driver circuit of the piezo transformer is also included in the design of this new step down transformer. It has been tested and proven to be working well in power conversion with excellent efficiency and reliability.  
WEPLS135 Piezoelectric Transformer Based Continuous-conduction-mode Voltage Source Charge-pump Power Factor Correction Electronic Ballast 2694
 
  • R.L. Lin, H.-M. Shih
    NCKU, Tainan city
  • C.-Y. Liu, K.-B. Liu
    NSRRC, Hsinchu
  
  This paper presents the piezoelectric transformer (PT) based continuous-conduction-mode (CCM) voltage source (VS) charge-pump (CP) power factor correction (PFC) electronic ballast. By replacing L-C resonant tank and transformer in the conventional CCM VS CP PFC electronic ballast with PT, the cost and volume can be reduced. The main drawback of conventional electronic ballast is that the input current has a narrow conduction angle, which causes rich harmonic that pollute the power system. However, the conventional CCM VS CP PFC electronic ballast is able to solve this problem but still require larger volume. Since the equivalent circuit of PT is identical to the conventional L-C resonant tank used in CCM VS CP PFC electronic ballast, the L-C resonant tank can be replaced by the PT to reduce the cost and volume. In addition, the inherent input capacitance of the PT works as a turn-off snubber for the power switches to decrease the turn-off voltage spikes and thus reduces the turn-off losses of the switches. The results show that the electronic ballast using PT achieved high power factor and the switches can be operated under ZVS condition.  
WEPLS136 Pulsed Magnet Power Supplies for Improved Beam Trajectory Stability at the APS 2697
 
  • B. Deriy, L. Emery, A.L. Hillman, G.S. Sprau, J. Wang
    ANL, Argonne, Illinois
  
  New power circuit and control electronics have been implemented in the septum power supplies at the Advanced Photon Source (APS). The goal was to meet a low pulse-to-pulse relative amplitude jitter of about ± 5·10-4 for trajectory stability in the booster-to-storage ring transport line. The original power supply design produced a jitter of ± 15e-4, which made injection tuning difficult. The jitter for the two new booster pulsed magnet supplies is now 1.1e-4, as inferred by a beam-based statistical analysis. A common design was made for all of the septum magnet power supplies at the APS. The system, regulation algorithms, the results achieved, and the current regulation stability issues will be discussed.