METHOD FOR AUTOMATIC TUNING OF PLUNGER ARC-SUPPRESSING COIL AND DEVICE FOR AUTOMATIC TUNING OF PLUNGER ARC-SUPPRESSING COIL Russian patent published in 2012 - IPC H02H9/00 

FIELD: electricity.

SUBSTANCE: in the absence of single phase-to-ground fault one performs automatic resonance tuning of the arc-suppressing coil inductance with the distribution grid capacity which includes creation of an artificially off-set neutral, measurement of neutral voltage phase angle 3U₀ and the latter comparison with the standard reference voltage phase. The device implementing the method contains a plunger arc-suppressing coil, the main winding (the output whereof is connected to the grid neutral), a control unit, a controllable commutator connected to the control unit output (the commutator output being the arc-suppressing coil plunger control input) and a measurement voltage transformer connected in parallel via the inputs to the distribution line phases. Additionally introduced are an address information bus, an asymmetric coupling transformer with an embedded neutral offset source, an AD conversion unit and a measurement transformer for the arc-suppressing coil main winding current. The control unit is represented is represented by a digital processor, the arc-suppressing coil containing two additional secondary windings: the control one and the signal one.

EFFECT: increased accuracy of resonance tuning, extension of functional capabilities and enhancement of the electric power grid operational reliability.

4 cl, 1 dwg