07 Accelerator Technology
T11 Power Supplies

Paper	Title	Page
TUODB03	Innovative Design of the Fast Switching Power Supplies for the SOLEIL EMPHU Insertion and its Fast Correctors	982
	F. Bouvet, D. Aballea, R. Ben El Fekih, S. Bobault, M. Bol, Y. Bouanani, Y. Dietrich, A. Hardy, F. Marteau SOLEIL, Gif-sur-Yvette, France
	A new electromagnetic/permanent magnets helical undulator has been designed and is under commissioning at SOLEIL. For a fast switching of the photon polarization, it requires a power supply able to switch between +/–350 A within 50 ms, without any current overshoot and with a very good current resolution over the full scale (50 ppm). The in-house design is based on two full switching bridges with interleaved commands. Combined with a regulation scheme using sophisticated algorithms, such a design enables to reach a high control bandwidth, permitting fast transitions. Such a fast and accurate system needs well performing digital control electronics. We chose the digital control cards developed at Paul Scherrer Institute (Villigen CH) for the SLS (Swiss Light Source). The components, measurements, interlocks, control interfaces, and electronic cards were developed and assembled together at SOLEIL. This paper will present the main lines of this development and the performances achieved during the EMPHU insertion commissioning. The design of the fast power supplies (±20 A) needed for corrector magnets of this insertion will also be presented.
	Slides TUODB03 [3.017 MB]
THPO001	Design Power Supply Considerations to Compensate Booster Power Supply Effects on the SOLEIL Storage Ring	3335
	J.-P. Lavieville, R. Ben El Fekih, S. Bobault, D. Muller, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	Top-up injection mode has been routinely in operation since March 2009 for various bunch filling patterns at Synchrotron SOLEIL. The electron beam stored current is maintained within 1%. At each injection the 3 Hz booster power supplies are ramped up and down over 10 seconds every 3 minutes in average. During this time DC and AC perturbations are observed on the storage ring horizontal closed orbit. Typically, the beamline source points can be shifted up to 10-20 μm and the amplitude of the 3Hz frequency is multiplied by a factor 9. The origin of these perturbations lies in the imperfect compensation of the magnet currents circulating along the booster ring located inside the storage ring. To compensate these disturbances, a wire loop was installed in the booster cable tray fed by an in-house developed power supply. Its output current is driven by direct measurement of the main currents of the booster dipole, quadrupole, sextupole power supplies with a proper amplitude and phase shift. This paper presents the determination of the compensation needs according to beam measurements, the original design and the performance reached when this power supply is acting.
THPO003	Rapid-cycling Power Supplies for the J-PARC RCS Sextupole Magnets	3338
	Y. Watanabe JAEA, Ibaraki-ken, Japan T. Adachi, S. Igarashi, H. Someya KEK, Ibaraki, Japan N. Tani JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The rapid-cycling synchrotron of the Japan Proton Accelerator Research Complex requires 18 sextupole magnets with three families for the chromaticity correction. One family consists of six focusing sextupole magnets, and other two families consist of six defocusing sextupole magnts. An individual power supply excited for each family and the current pattern is a DC-biased sinusoidal of a frequency of 25 Hz. This paper describes design and test results of the sextupole magnet power supplies.
THPO004	An Active Power Filter Based on Wavelet Analysis	3341
	X.L. Guo Private Address, Beijing, People's Republic of China X.L. Guo IHEP Beijng, Beijing, People's Republic of China
	As modern accelerator demands a magnet supply with a much higher stability, it is important to improve the quality of the magnet supply. An effective method to improve the output performance active power filter (APF) applied in current supply is proposed. To lowdown the harmonic constituents, the APF circuit generates a harmonic current, which added to the current from the main power supply, to countervail the ones in the supply’s current. At end of this paper, a simulation result is given to prove the effect of APF.
THPO005	A Dipole Power Supply Based on Multi-lever Inverter Technique	3343
	Y.X. Chen, D.Q. Gao, Y.Z. Huang, R.K. Wang, H.B. Yan IMP, Lanzhou, People's Republic of China
	By applying multi-lever inverter technique to ion accelerator power supply, it can provide steady current in wide range, increase the power supply’s equivalent output frequency, then further promote power supply’s response capability and reduce the output ripple current. This article firstly by giving a detailed introduction of composite and basic working process of dipole power supply which also applied the technique mentioned above, interpret the working principle of multi-lever inverter, and illustrate its advantages. However, applying this technique will make controller more complicated, which need to be overcome by digital regulator technique. And meanwhile digital regulator technique can improve the power supply's performance. The second part of this article briefly introduces the overall scheme of digital regulator. And at last, this article illustrate the dipole power supply meet to design target and make some improvement by using the practical results to prove that applying multi-level inverter technique into accelerator power supply is practicable and beneficial.
THPO006	A Digital Power Supply Control Model in Heavy-ion Accelerator based on Dual Nios Cores	3346
	R.K. Wang, Y.X. Chen, D.Q. Gao, Y.Z. Huang, H.B. Yan, H.H. Yan, Z.Z. Zhou IMP, Lanzhou, People's Republic of China R.K. Wang Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
	According to the features of digital power supply and the requirements of pulse mode,this paper introduces a Digital Power Supply Control Mode(DPSCM) in Heavy-Ion Accelerator based on dual Nios cores,which meets the requirements of two basic running modes. The new method develops a system on-chip based on dual Nios cores by using SOPC technology in the Altera EP2C70 FPGA. Compared with traditional DPSCM,the dual Nios cores run simultaneously and cooperate well. As a result,the efficiency of the system is remarkably improved. Further,cores in parallel can realize reference waveforms switch in pulse mode effectively. We choose a 1150A/185V power supply as test bench. The Experimental result indicates that the system can realize the function of pulse mode,and the stability and tracking error meet the design requirements.
THPO007	Operation Status of SSRF Power Supplies and Interlocks for Top-up Operation	3349
	R. Li, C.L. Guo, M.M. Huang, T.J. Shen SINAP, Shanghai, People's Republic of China
	Digital switching mode magnet power supplies are used in SSRF accelerators which have been operating since 2008. Summary of the operation and maintenance of these power supplies will be shared over here. The availability of the power supplies is increased steadily over the past 4 years. And the power supplies interlocks for the SSRF top-up operation will be also introduced in this paper.
THPO008	Klystron and Modulator System for the PEFP 20 MeV Proton Linac	3352
	D.I. Kim, Y.-S. Cho, H.S. Kim, H.-J. Kwon KAERI, Daejon, Republic of Korea
	Funding: This work is supported by the Ministry of Science and Technology of the Korean government. A modulator developed for the 100 MeV proton linear accelerator is operating in the 20 MeV proton linac. The voltage and current of the modulator are -105 kV, 50 A with 1.5 ms pulse width, 60 Hz repetition rate. The modulator drives two klystrons simultaneously, one for the RFQ, the other for the DTL. The typical operation parameters of the modulator are 85 kV of the peak voltage, 34 A of the peak current, 1 ms of the pulse width, 4 Hz of the pulse repetition. The specifications of the klystron are 350 MHz of the frequency, 1.1 MW of the maximum average RF power, less than 95 kV of the beam voltage, triode type electron gun with mod-anode. The mod-anode voltage was supplied by the voltage dividing resistors which were located inside the klystron oil tank. In this paper, the operation performance of the klystron and modulator system for the PEFP 20 MeV proton linac is presented.
THPO011	Practical Experience with Self-optimizing, High Dynamic Control of Accelerator Magnet Power Supplies	3355
	H. Jäckle PSI, Villigen, Switzerland F. Jenni, X.H. Ke FHNW, Windisch, Switzerland
	In 1999, the first fully digitally controlled magnet power supplies were commissioned at PSI (Paul Scherrer Institute, Switzerland). Today, approximately 1000 of them are in use at PSI and a multiple of that worldwide. An extended PI structure is used for control. PI control is very effective and simple to use but the attainable dynamic performance is usually limited by the higher order characteristics of the output filter and the load. For the future we expect increasing requirements from highly dynamic applications, such as beam orbit feedback systems and fast scanning magnets for proton irradiation of tumors. Therefore, a self-optimizing power supply control system was developed in collaboration with the University of Applied Sciences Northwestern Switzerland. It is based on the second generation of PSI digital power electronics controller, which allows more complex control algorithms and higher sampling rates. This paper presents the achieved dynamic performance of the new control structure for various types of power supplies and magnets and compares them with the dynamic performance obtained using standard PI control.
THPO012	Using a High Precision Programmable DC Power Supply of TPS Magnet	3358
	Y.S. Wong, J.C. Huang, K.-B. Liu, W.S. Wen NSRRC, Hsinchu, Taiwan
	Taiwan government had been announcement to set up a third-generation synchrotron radiation light source in February 2010. It should be installed with 1032 sets of magnet power supplies for the storage ring and 152 sets for the injector. In the storage ring, high precision DC power supply for 48 dipoles magnets , 240 quadrupole magnets and 168 sextupole magnets. The main windings of quadrupole and sextupole magnets are powered by individual power supplies. In the booster rings, one set of dynamic power supply for the dipole magnets and four sets for quadrupole magnets run at the biased 3Hz quasi sinusoidal wave. The Taiwan photon source (TPS) plan was completed indication national synchrotron radiation research central (NSRRC) technical capability to build at its present site in seven years a 3~3.3 GeV electron energy, 518 meter circumference, low-emittance synchrotron storage ring which will offer one of the world's brightest synchrotron x-ray sources, provide cutting-edge experimental facilities and novel multidisciplinary scientific research opportunities, enhance world-class academic research, as well as create Taiwan's scientific research marvels in the twenty-first century.
THPO013	Development of a DSP-based Digital Control Three Phase Shunt Active Power Filter for Magnet Power Supply System	3361
	B.S. Wang, K.-B. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	There will be 240 quadruple and 168 sextuple magnet power supplies installed in TPS storage ring, power factor of these power supplies is an important issue to be concerned. A digital control three-phase shunt active power filter (APF) for quadruple and sextuple magnet power supplies is implemented and the power factor is better than 0.98. The APF power stage employs a three-phase switch-mode rectifier (SMR) to reduce the input current harmonics distortion and correct the power factor. The digital control circuit of the three-phase shunt active power filter is implemented by using a multi-channel 12 bits analog-to-digital converter、high resolution Pulse Width Modulated (PWM) and a TMS320F28335 digital signal processor (DSP). The system configuration is described in three function blocks include principle of compensation、design of the snubber protective circuit and control strategies. Finally, the feasibility and validity of proposed scheme is simulated with Matlab simulink and verified by the homemade digital control three-phase shunt active power filter.
THPO014	Analysis and Compensator Design of Magnet Correction Power Supply	3364
	Y.S. Wong, J.C. Huang, K.-B. Liu NSRRC, Hsinchu, Taiwan
	This paper presents a new method for the analysis and design of compensators for magnet correction (MC) power supply. The system has to need controllers to satisfy required gain and phase margin specifications and compensator by adding to circuit controller and switch. The gain-phase margin tester method can transform of the controller and find solutions on the figure. According to circuit frequency response and transfer function by theory analysis and simulation design new method compensators to improved anti-disturbance and stability of the system.
THPO015	External Energy Dump for Superconducting Magnet of the Uni-polar Power System	3367
	Y.S. Wong, K.-B. Liu, W.S. Wen NSRRC, Hsinchu, Taiwan
	This thesis focuses on the design of superconducting discharge energy circuit structure in Uni-polar power supply [1]~[3]. Superconductivity is an electrical resistance of exactly zero which occurs in certain materials below a characteristic temperature [4]. It’s operation at the steady state in constant temperature area. When Rise up resistance and temperature of superconductivity will have been dissipates function. Uni-polar power supply has needed to design discharge energy circuit when superconductor reduces the current. To make use release the energy transfers to external circuit keep the constant temperature with the superconductivity. The superconducting coil wingding has a total length magnetic period of 56.56cm, total magnet length of 478.9cm and vertical (horizontal) magnetic field of 18.7T.
THPO016	Design and Implementation the LLC Resonant Transformer	3370
	C.-Y. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	The energy and dc to dc conversion voltage waveform of the LLC resonant transformer are required to achieve optimal working condition of the resonant region frequency. To meet this requirement, a reliable and precise instrument is needed to scan the resonant cure of the LLC resonant transformer such that its output power performance can meet the required specification. In this paper, the design and model of a new LLC resonant transformer deployed in NSRRC is described. This LLC resonant transformer is capable of delivering energy conversion with high efficiency performance, which is better than traditional transformer, and the voltage transfer ratio is depended on the resonant Frequency. Using the simulation circuit model to develop a power converter of it is also included in the design of this new LLC resonant transformer. It has been tested and proven to be working well in power conversion with excellent efficiency and performance.
THPO017	Improvement of Output Current Characteristics for Bira MCOR30 Correction Magnet Power Supply	3373
	J.C. Huang, K.-B. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	The correction magnet power supplies installed at the Taiwan light source (TLS) are Bira Systems’ MCRO 30 power modules, a full-bridge configuration power stage converting the unregulated DC bulk power into a bi-polar current source. The MCOR 30 is theoretically regulated under a very fine control method, with this control method the Bira MCOR 30 should overcome the zero crossover distortion of a standard H-Bridge PWM schemes is used and result in a low frequency noise signature on the output when the magnet current is close to zero. The PWM control circuitry embedded in MCOR 30 theoretically but not really fulfills the purpose what the MCOR 30 want to achieve. With a home-made PWM control circuitry installed into MCOR 30, the width of real pulses can smoothly drop to zero, the MCOR 30 could output current not only with a low frequency noise signature but also much with higher bandwidth of frequency response and much lower Total Harmonic Distortion no matter what output current is demanded.
THPO018	N+1 Redundancy Power Supply System by Paralleling Current Converter Modules with Digital Regulation Control	3376
	B.S. Wang, K.-B. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	The N+1 redundancy power supply system is fulfilled with adopting the Bira System MCOR30s as a platform, eight pieces of Bira MCOR 30 power converter boards are installed at crate 2512 and outputs are connected together, the output current of these paralleled eight Bira MCOR 30 power converters are regulated by an external homemade digital control circuit. With homemade digital control circuit, these paralleled eight Bira MCOR 30 power converter modules could deliver up to 240A/30V with ±20ppm precision and stability. The digital regulation control circuit of the N+1 redundancy power supply system is implemented by using a multi-channel DAC5868 16-bits digital-to-analog converter (DAC)、a high speed AD8382 18-bits analog-to-digital converter and a TMS320F28335 digital signal processor (DSP). The update reference voltage frequency of DAC is 83.3 kHz. A DCCT is used as the current feedback component and the output current ripple of the N+1 redundancy power supply system is lower than 20ppm which is beyond the requirement of current TLS quadruple and sextuple power supplies and qualified to be used in the future TPS facility.
THPO019	TPS Fast Corrector Magnet Power Converter	3379
	Y.D. Li, K.-B. Liu NSRRC, Hsinchu, Taiwan
	With the increasing demand of the current output accuracy on the TPS(Taiwan Photon Source) project, the MCOR 30 correction power supplies used in current TLS ring are no longer sufficient to meet the TPS requirement. Therefore, power supply group developments a high-precision low output current power supply with a DCCT as an output current feedback component for correction magnets of the future TPS ring. During the research and development experiment phase, we found the DCCT is more possible damaged than the other components. With keeping the architecture of the high-precision low output current power supply, but the DCCT output current feedback component is replaced with a current sensing Shunt resistor. This paper will discuss the design methods of utilizing several different types current sensing Shunt resistor to reduce the cost of power supply and the probability of damage, and improve frequency response of power supply.
THPO020	TPS Digital Corrector Magnet Power Converter based on FPGA	3382
	Y.D. Li, Y.-C. Chien, K.-B. Liu NSRRC, Hsinchu, Taiwan
	This thesis presents the design and implementation of a FPGA-based fully digital-controlled programmable power supply.
THPO021	A New Control System for the ISIS Main Magnet Power Supply	3385
	J. Ranner, T.E. Carter, S. West STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory in Oxfordshire is a world-leading centre for research in the physical and life sciences. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of dipole and quadrupole magnets connected in series and configured as a White Circuit*. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. A recent upgrade to the main magnet power supply** involved the replacement of the original AC supply, a motor-alternator set, with a bank of four 300kVA UPS (uninterruptible power supplies) which had been modified to allow the output voltage to be varied using serial commands. However, when initially tested, this method was unable to produce the required stability in the main magnet current. This paper describes the further modifications to the UPS units to achieve the required stability and the development of a LabVIEW control system which manages the data acquisition and analysis, the communication to the UPS, interlock equipment and user interface, and provides a low latency control loop to the UPS and DC bias power supplies. * M.G. White et al., “A 3-BeV High Intensity Proton Synchrotron”, CERN Symp.1956 Proc., p525. ** S. West, J.W. Gray, W.A. Morris, “Upgrade of the ISIS Main Magnet Power Supply”, EPAC 2004 p1467.