Accurate fault locating method for double circuit lines on same pole

Abstract

The invention discloses an accurate fault locating method for double circuit lines on the same pole, which is used for solving the problems of locating errors caused by unavailability of avoiding mutual impedance and mutual susceptance phase difference among leads and the realization of fault location in any fault existing in the conventional fault locating method for double circuit lines on the same pole. According to the accurate fault locating method, an accurate fault calculation method is adopted. The accurate fault locating method comprises the following steps of: 1, calculating measured values of current and voltage vectors before and after a fault with a Fourier algorithm; 2, calculating impedance matrixes and potentials of systems on both sides; 3, calculating to obtain a transfer matrix ranging from fault points of the double circuit lines on the same pole to a bus by using different fault distance values with a feature modulus decomposition method; 4, constructing a resistance matrix of the fault points by using different fault resistance values; 5, solving an equation to obtain calculated values of voltage vectors of buses on both sides and current vectors from a circuit to a bus; and 6, calculating an error quadratic sum of each vector calculated value and measured value. In different values of a fault distance and fault resistance, the error quadratic sum calculated by using a fault distance and a fault resistance value which are most proximate to a practical fault distance and practical fault resistance in the step 6 is least.

Description

technical field [0001] The patent of the present invention relates to the field of relay protection of power system transmission lines, in particular to the precise measurement of the fault distance (abbreviated as fault distance measurement) when the ultra-high voltage double-circuit line on the same pole and the UHV double-circuit line on the same pole are randomly faulted. Background technique [0002] The double-circuit line on the same pole has the characteristics of high reliability, less land occupation, and low investment, and is widely used in high-voltage transmission systems. Various short-circuit faults may occur in double-circuit lines on the same pole during operation. Since the double circuit line on the same pole has 6 conductors, and there are more than one hundred kinds of fault combinations, there is currently no method that can accurately measure the distance to fault when any fault occurs on the double circuit line on the same pole. The ultra-high volta...

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Problems solved by technology

[0003] In order to overcome the current fault location methods of various ultra-high voltage double-circuit lines on the same pole and UHV double-circuit lines on the same pole, the distance measurement error caused by the mutual impedance and mutual susceptance difference between the wires cannot be avoided, and the fault location can be realized when any fault occurs. distance problem

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