Impedance monitoring method for low-voltage distribution network neutral line abnormity

The invention discloses an impedance monitoring method for low-voltage distribution network neutral line abnormity, and the method comprises the following steps: selecting any transformer area, and obtaining the voltage and current curve data of all electric energy meters in the transformer area and the phase information of the electric energy meters from an acquisition system; the method comprises the following steps: acquiring a voltage average value and a current vector sum of all electric energy meters of the same phase under a meter box by taking the meter box as a basic unit according to an existing transformer area topological structure and a shunt membership relationship as voltage and current of the phase of the meter box; establishing an impedance calculation model from the meter box to the low-voltage side of the transformer in the transformer area by combining the Kirchhoff voltage and current law; calculating the phase line impedance and the neutral line impedance from the meter box to the low-vo