GROUNDING DEVICE OF THREE-PHASE ELECTRICAL NETWORK NEUTRAL Russian patent published in 2012 - IPC H02H9/00 H02H3/20 

FIELD: electricity.

SUBSTANCE: stated device consists of grounding resistor with constant active resistance connected to electrical network neutral by one of outputs and with the second output connected to relative anode of bidirectional thyristor, the relative cathode of which is grounded. Capacitive voltage divider is connected between network neutral and earth. The lower leg of voltage divider is connected to the primary winding of the transformer, the second winding is connected to the control electrode of bidirectional thyristor and its relative cathode. In case of unstable arcing faults the bidirectional thyristor opens and connects the resistor to the network reducing excessive voltage. In case of stable fault the thyristor is closed and grounding resistor is disconnected from the network.

EFFECT: improvement of self-quenching conditions of earthing arc and reduction of its burning period, improvement of network safety, decrease of energy losses in grounding resistor and its power.

2 dwg