METHOD TO DETERMINE AREA OF DAMAGE IN CASE OF SHORT CIRCUITS IN NEUTRAL LINES THAT CONNECT CONVERTING SUBSTATIONS OF DC POWER TRANSMISSION Russian patent published in 2013 - IPC G01R31/08 

FIELD: electricity.

SUBSTANCE: invention may be used for damage area detection (DAD) in neutral lines, which connect middle points of high-voltage converting DC power transmission substations (DCS). Current instantaneous values of emergency currents are recorded at the ends of each neutral line (11, 12), permanent components are identified in them, and the distance is calculated to the damage area, using the ratio of active resistances of neutral wire sections in accordance with the formula: $$l_x=\frac{r_1\cdot i_{11}-r_2\cdot i_{21}}{r_0\cdot (i_{22}-i_{21})},$$ where r₁ - active resistance of a non-damaged neutral wire, r₂ - active resistance of a damaged neutral wire, r₀ - active resistance per unit length of neutral wires, r₁₁ - permanent component of current in the beginning of the non-damaged neutral wire, r₂₁ - permanent component of current in the beginning of the damaged neutral wire, r₂₂ - permanent component of current in the end of the damaged neutral wire.

EFFECT: improved validity of remote detection of a damaged area in lines of DCS neutral wires in case of earth faults.

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