NEUTRAL GROUNDING METHOD Russian patent published in 2021 - IPC H02H3/20 H02H9/04 

FIELD: power industry.

SUBSTANCE: invention relates to the field of electric power engineering to reduce the single-phase short-circuit current and maximum overvoltages in electric networks. The neutral grounding method involves connecting capacitors to the network that are grounded through a reactor and a resistor connected in series. In parallel with the capacitors, a varistor is turned on, and the resistor is shunted with a normally closed key, with the possibility of opening when the reactor current reaches a critical value. The varistor opening voltage and the critical value of the reactor current are selected in compliance with the condition (U₀ - U_C)² + (IR)² ≤ Е², where U₀ is the amplitude of the voltage at which the reactor is saturated; U_C is the varistor opening voltage; I is the critical value of the reactor current; R is the reactor resistance; E is the amplitude of the phase EMF of the power grid.

EFFECT: increase in the reliability and safety of the power grid by simultaneously reducing the maximum overvoltages, reducing the current of single-phase short circuits and eliminating the possibility of ferroresonance in unstable single-phase arc short circuits.

3 cl, 4 dwg, 1 tbl