Operation of Accelerators Directly off the Utility System

The operation of accelerators directly off the utility line is primarily restricted by the voltage fluctuation it causes on the utility system. To limit the voltage fluctuation, it will be necessary to design equipment and circuitry to reduce the MVARs during flat-topping and at the beginning of inversion. The advantages gained with the elimination of motor generator (M-G) sets will outweigh any disadvantages of more complicated equipment and possible operating restrictions. Based on a one second acceleration time, restricted MVAR during flat-topping and a range of 0.5%-1% voltage fluctuation, the stored energy in the ring magnet in MJ may be between 0.25% and 0.5% of the short circuit capacity (SCC) of the system at the point the accelerator is interconnected. Action of the generator voltage regulators will reduce the calculated voltage flicker or the required SCC. There are many systems that are large enough to permit direct operation of medium sized accelerators or standby operation of large accelerators at reduced capacity. Large accelerators will require large utility systems.