High Current, Low Voltage Power Converters for LHC. Present Development Directions

The superconducting LHC accelerator requires high currents (12.5kA) and relatively low voltage (~10V) for its magnets. The need to install the power converters underground is the driving force for reduced volume and high efficiency of the power converters. Moreover, the machine will require a very high level of performance from the power converters, particularly in terms of DC stability and dynamic response. To meet these requirements switch-mode techniques will be used. This paper gives a survey of current switch-mode converter topologies for high DC current output. The presentation is primarily focused on the various methods for low-loss switching in DC power converters operating with high switching frequency (20 50 kHz). A modular concept is being studied, using several current sources in parallel, to adapt to the various circuits and also provide redundancy.