Mitigation of voltage sag effects on sensitive plants: an exemplary case study

Abstract Process-interruptions and related costs often force industrial customers to adopt proper solutions to mitigate the voltage sags effects. A trivial solution would be to feed the whole plant through UPS devices, but in many cases this would be technically or economically not practical. Partial solutions given by proper changes in the plant or desensitising critical equipment often become the most viable way. This paper deals with an exemplary case study given by Elettra, the synchrotron light source facility of Trieste (Italy). After a description of the facility, the paper illustrates a methodology, based on field measurements and experimental tests, aiming to individuate proper local actions that will drastically reduce the effects of voltage sags on the considered plant. The methodology described with reference to this particular case study has general validity and may be regarded as an approach ‘guideline’ to the problem.