Author: Magrans de Abril, M.
Paper Title Page
MOPGF090 Control of Fast-Pulsed Power Converters at CERN Using a Function Generator/Controller 1
  • R. Murillo-Garcia, Q. King, M. Magrans de Abril
    CERN, Geneva, Switzerland
  The electrical power converter group at CERN is responsible for the design of fast-pulsed power converters. These generate a flat-top pulse of the order of a few milliseconds. Control of these power converters is orchestrated by an embedded computer, known as the Function Generator/Controller (FGC). The FGC is the main component in the so-called RegFGC3 chassis, which also houses a variety of purpose-built cards. Ensuring the generation of the pulse at a precise moment, typically when the beam passes, is paramount to the correct behaviour of the accelerator. To that end, the timing distribution and posterior handling by the FGC must be well defined. Also important is the ability to provide operational feedback, and to configure the FGC, the converter, and the pulse characteristics. This paper presents an overview of the system architecture as well as the results obtained during the commissioning of this control solution in CERN's new Linac4.  
poster icon Poster MOPGF090 [8.193 MB]  
WEC3O02 The Phase-Locked Loop Algorithm of the Function Generation/Controller 1
  • M. Magrans de Abril, Q. King, R. Murillo-Garcia
    CERN, Geneva, Switzerland
  This paper describes the phase-locked loop algorithms that are used by the real-time power converter controllers at CERN. The algorithms allow the recovery of the machine time and events received by an embedded controller through WorldFIP or Ethernet-based fieldbuses. During normal operation, the algorithm provides less than 10 μs of time precision and 0.5 μs of clock jitter for the WorldFIP case, and less than 2.5 μs of time precision and 40 ns of clock jitter for the Ethernet case.  
slides icon Slides WEC3O02 [1.886 MB]  
WEPGF106 CCLIBS: The CERN Power Converter Control Libraries 1
  • Q. King, K.T. Lebioda, M. Magrans de Abril, M. Martino, R. Murillo-Garcia
    CERN, Geneva, Switzerland
  • A. Nicoletti
    EPFL, Lausanne, Switzerland
  Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit's voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit's reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these different cases are supported by the CERN Converter Control Libraries (CCLIBS), which are open-source C libraries that include advanced reference generation and regulation algorithms. This paper introduces the libraries and reviews their origins, current status and future.  
poster icon Poster WEPGF106 [2.797 MB]