Jean-Paul Burnet

A novel 60 MW pulsed power system based on capacitive energy storage for particle accelerators

Large Physics experimentation as in particle accelerators or in nuclear fusion is often characterised by a strong and modulated power demand, incompatible with the power availability of the grid. Therefore, large facilities for short-term energy storage have been used, traditionally based on rotating machine. Several new solutions of power supply are studied and especially a new solution for energy storage is presented, where capacitors are used as energy storage elements. They are integrated in the static power converter. The energy- and instantaneous power-demand are presented, and then the global storage system with a dedicated multilevel DC/DC converter with flying capacitors is described. A specific control strategy for voltage balance, together with an adapted loss compensation method is also introduced and developed.

A Multilevel Power Converter with Integrated Storage for Particle Accelerators

The PS accelerator (proton-synchrotron) at CERN (European Organization for Nuclear Research) is composed of one hundred magnets connected in series. During a cycle of 2.4 seconds, the active power at the magnets terminals varies from plus to minus 40 MW. As this large active power variation was not acceptable to the electrical network, a motor-generator set (M-G) was inserted between the grid and the load in 1968. The M-G set acts as a fly-wheel with a stored kinetic energy of 233 MJ and the magnets are fed by two 12-pulse thyristor rectifiers. After forty years of operation, the system has to be replaced. This paper presents a possible solution for a power system based on capacitive storage.

A 4-quadrant 300kW-peak high precision and bandwidth switch mode power converter for particle accelerator magnets supply

A switch mode AC/DC-DC power conversion topology is proposed for the supply of particle accelerator correction magnets, requiring simultaneously high peak power (300 kW), high bandwidths (1 kHz in voltage, 300 Hz in current), high current precision (10-4), EMC emissions according to international standards and current/voltage reversibility (4-quadrants operation). The power part dimensioning key issues are presented, including semiconductor power cycling design, high frequency power filtering, DC-link bus stability analysis. The feedback controls strategy and suited PWM techniques are reported. Experimental results are presented and commented.

POPS: The 60MW power converter for the PS accelerator: Control strategy and performances

The main power supply of Proton-Synchrotron (PS) accelerator is one of the biggest at CERN. The old rotating machine system has been replaced with a new NPC based DC/DC power supply named POPS (Power system for PS main magnets) with capacitor banks as energy storage mean. POPS is in operation since February 2011. The operation of the PS accelerator requires a specific design of the control system with very high performance requirements in term of accuracy and precision. This paper describes the main lines of the control strategies analyzing the problems encountered and the solutions adopted. The performances of the converter are presented throughout the paper.

High-current low-voltage power supplies for superconducting magnets

In a synchrotron accelerator, the beam trajectory is controlled thanks to magnets, where superconducting technology allows to generate very strong magnetic fields. This was a key element in the construction of the Large Hadron Collider (LHC), the world largest accelerator. Such magnets need special power supplies providing very high DC current under low voltage. In the frame of High Luminosity-LHC (HL-LHC), stronger superconducting magnets are developed and require enhanced supplies. This article reviews the present power supply topologies and introduces new concepts: HL-LHC project offers an opportunity for upgraded system, increased operational performances as well as integrated energy storage to recover energy from the superconducting magnets.

EPE’15 ECCE - Europe

The EPE’15 ECCE Europe conference is hosted by CERN. Founded in 1954, the CERN laboratory sits astride the French-Swiss border near Geneva. It was one of Europes first joint ventures and now has 21 member states. At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. They use the worlds largest and most complex scientific instruments to study the basic constituents of matter – the fundamental particles. The year 2012 was marked by one of the most significant events in Fundamental Physics: the experimental discovery of the Higgs Boson at CERN. Subsequently, the Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs.