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Liu, K.-B.

Paper Title Page
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.  
THPCH144 The Upgrading of the TLS Injector Bumper and Septum Power Supplies for Top-up Operation 3128
 
  • C.-S. Fann, K.-T. Hsu, S.Y. Hsu, J.-Y. Hwang, K.-K. Lin, K.-B. Liu, Y.-C. Liu
    NSRRC, Hsinchu
  
  Due to the inevitable requirement of routine top-up mode operation at TLS (Taiwan Light Source), the reliability of all components in TLS injector has been reevaluated in the past several months. Among all possible subsystems to be reinforced, the bumper and septum power supplies revealed urgent need of upgrading while operated continuously in the user shifts. In this report, the modification of the charging mechanism of the pulsed power supplies is described. The modular feature of the newly built units provides fast replacement capability in case of components failure. The unified specifications for all components have greatly reduced the effort in preparing spare parts. The test results of these units are presented in this report.  
THPLS066 Improvement on the Single Bunch Operation of the TLS Injector 3439
 
  • J.-Y. Hwang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.H. Hu, S.H. Lee, K.-K. Lin, K.-B. Liu, Y.-C. Liu
    NSRRC, Hsinchu
  
  The improvement of the TLS (Taiwan Light Source) injector on single bunch operation is presented in this study. Limited by the existing design of the TLS injector, the single bunch operation was not optimized in terms of bunch purity for specific users of TLS. A high voltage pulser was implemented to improve the situation. This pulser has been integrated into the high-voltage-deck electronics of electron gun for single bunch generation. Both high-voltage pulses and the associated electron bunches are monitored with a wideband digital oscilloscope. The result shows that the bunch purity can be greatly improved by using the newly installed pulser. It also greatly eliminates the beam losses while injected into the booster ring.  
THPLS069 Preliminary Design of the TPS Linac to Booster Transfer Line 3448
 
  • Y.-C. Liu, H.-P. Chang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.-K. Lin, K.-B. Liu, G.-H. Luo
    NSRRC, Hsinchu
  
  The preliminary design of the LTB (linac to booster) transfer line of the proposed TPS (Taiwan Photon Source) project is considered in this study. The layout presented in this report is based on the booster lattice and the choice of linac parameters. These parameters are adopted from previous report of booster design and typical commercial available products of linac. The simulation result indicates that the desired optical functions at a given location can be readily obtained by varying the appropriate focusing strength of quadrupoles. It provides tuning capability to match various possible options of optical functions at injection location. This report is presented together with design consideration of a set of beam diagnostics instruments.