METHOD FOR LOCATING WIND POWER GENERATION AND TRANSMISSION SYSTEM LINE SINGLE-PHASE GROUNDING FAULT

摘要

A method for locating a wind power generation and transmission system line single-phase grounding fault. The method comprises: obtaining a measured impedance expression according to loop impedance or reactance of a wind power generation and transmission system line single-phase grounding short-circuit being in direct proportion to the distance from a measurement point to a fault point; establishing a mathematical model of a measurement-end voltage with respect to a zero sequence current, a positive sequence impedance and a transition resistance; simplifying the mathematical model of a measurement-end voltage according to the included angle between a current flowing through a measurement end and the zero sequence current flowing through the transition resistance being very small; and in order to eliminate the influence of the transition resistance on fault distance measurement, simultaneously multiplying both sides of the simplified mathematical model of the measurement-end voltage by I0*, i.e. zero-sequence current conjugate complex numbers, only taking imaginary parts, determining the location of the fault point according to the ratio of a measured impedance to a line impedance, and determining the location of a wind power transmission line fault point by means of calculating the percentage m of a line fault distance in the total line distance. In the method, a wind power generation and transmission system line single-phase grounding fault point is located by means of an impedance distance measurement method.