FIELD: electric power supply. SUBSTANCE: device has power transformer which high-voltage winding is star-connected with available neutral. Line terminals are linked through three-phase commutation gear to phases of power supply section and neutral is directly connected to line terminal of single-phase arc-control reactor which zero lead is solidly grounded. It also includes voltage transformer which high-voltage winding is star-connected with solidly grounded neutral, three-phase arc-control plant which high-voltage winding is star-connected with solidly grounded neutral. Line leads of it are directly connected to line leads of high- voltage winding of power transformer. Device single-phase transformer has high-voltage winding which is connected with line lead directly to neutral lead of high-voltage winding of power transformer in parallel to single-phase arc-control reactor and with zero lead to ground. Line and zero leads of low-voltage winding are connected to resistor and single-phase commutation gear coupled in series. Zero lead is solidly grounded. Two control circuits consist of secondary circuits of current transformers in solidly grounded neutrals of high-voltage windings of voltage transformer and three-phase arc-control plant which leads are connected in parallel and linked directly to leads of relay protection unit which leads are coupled to unit for switching on of single-phase commutation gear. EFFECT: improved operational characteristics. 1 dwg
