Status of the LHC Power Converter Controls
Q.King* (CERN)
The LHC has more than 1700 power converters spread around the 27 km machine. Controlling them all is an unprecedented challenge due to the part-per-million level accuracy required for the main circuits and because the majority of the systems are exposed to significant levels of radiation. The project started in 1996 and consumed 7 MSF and around 50 man years. The architecture chosen is similar to the one used successfully in LEP with one embedded controller per power converter linked by fieldbuses to middle-tier gateway systems. This paper presents a summary of the architecture and the results achieved during the commissioning of the LHC from 2006-8. The system contains numerous enhancements compared to LEP including: digital regulation of current; automatic configuration based on a machine readable inventory; extensive remote diagnostics of power converter and controller faults; and distribution of time of day, timing events, software updates and power cycle requests over the WorldFIP fieldbus. The paper reports on what worked well, what could have been designed better, and what are expected to be the important issues for exploitation in the future.