Presentation by Giuseppe Cappai EN-EL-MO

Abstract:

A 3.15 MVA 18/0.4 kV transformer powering the radiofrequency (RF) amplifiers of the Super Proton Synchrotron accelerator at CERN exhibited intense anomalous noise during the so called “cavities training”. A root cause analysis was conducted covering the following activities: transformer inspection, on-site electrical, thermal and acoustic measurements, and electromagnetic simulations. The presentation describes the multidisciplinary approach used to identify the root causes, including those related to RF pulses generation and the interaction with the upstream power system, along with the formulation of a theory regarding the origin of the phenomenon and the analytical identification of the specific harmonic frequencies involved.

Finally, the solution adopted to minimize both the noise generated by the transformer and the harmonic pollution of the network is presented.