Probabilistic assessment and evaluation of transients in a medium voltage three-phase capacitor bank energized by unsynchronized vacuum switchgears

This paper presents a case study of a medium voltage three-phase capacitor bank energization, based in an unsynchronized switching scheme using three independent pole vacuum switch simultaneously commanded. The motivations are cost reduction and simplification of the switching scheme. The maximum current and voltage peaks during transients caused by connection of capacitor bank with three independent pole switches or three-phase mechanically coupled switch are compared. A probabilistic assessment for the overcurrents and overvoltages based in Monte Carlo simulation is also performed. The obtained results show that three single-phase unsynchronized switches could be used in a capacitor bank, with good transitory response.