Application of single-pole auto reclosing of circuit breakers in EHV transmission line with capacitance grounding

Tripping of one pole of circuit breakers at both ends of a transmission line for clearing LG fault produces high negative sequence current in nearby generators. Insertion of grounding capacitor connected between the ground and neutral point of star winding of a transformer at one end of the transmission line during the period of open conductor makes the net zero sequence reactance to be zero. The zero sequence network shunts the negative sequence network and the negative sequence current is reduced to a negligible value. The power transfer with one phase open, during single pole auto reclosing becomes equal to pre-fault power and the transient stability limit is highly improved. Power swing associated with a successful auto reclosure becomes minimum. The sudden change in generator output power at the instant of reclosing is reduced to a minimum.