Method for constructing physical model of double circuit transmission lines on same tower

Abstract

The invention provides a method for constructing a physical model of double circuit transmission lines on the same tower, which comprises the steps of: reducing the mutual inductance influence of a ground wire to self-impedances of all transmission lines and mutual impedances among phases first, calculating equivalent self-impedances of the phases and equivalent mutual impedances among the phases after the reduction, taking the smallest equivalent mutual impedance as a common resistance M<min>, and calculating a mutual compensating impedance Z<ik> between the i-th phase and the k-th phase of the transmission line of which the mutual impedance is larger than the common resistance, and a self-compensating impedance Z of the i-th transmission line; and then utilizing the common resistance M<min>, the mutual compensating impedance Zik and the self-compensating impedance Z of each transmission line to construct the physical model of the transmission lines. The method adopts a strategy of fully simulating the self-inductances of the transmission lines and the mutual inductances among the lines, and considers the influence of a ground return circuit and the ground wire when the self-inductances and the mutual inductances of the transmission lines are calculated. The method can effectively overcome the defects of the prior physical model of the double circuit transmission lines on the same tower, can well simulate transposed or un-transposed double circuit transmission lines on the same tower, and accurately reflect the variation characteristics of electrical quantity when the double circuit transmission lines on the same tower break down.

Description

technical field [0001] The invention belongs to the field of electric power system automation, and in particular relates to a method for constructing a physical model of a double-circuit power transmission line paralleled on the same pole, and can also be used for the construction of physical models of other types of power transmission lines. Background technique [0002] The performance analysis and evaluation of various protection and control devices in the power system need to rely on theoretical research and test results, and the physical model is the basis for experimental research and digital simulation verification, that is, the proposed principles and schemes need to be verified by dynamic model tests . So far, in view of the structural characteristics of parallel lines on the same pole, the design schemes for the dynamic physical model of double-circuit lines on the same pole have been proposed in China. There is a double-circuit line model on the same pole based on...

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Problems solved by technology

Several existing models simplify the actual parallel lines on the same pole, only considering the influence of zero-sequence mutual inductance between the two loops, and it is difficult to truly reflect the electrical quantity change characteristics when the parallel lines on the same pole fail. Especially in occasions where the positive and negative sequence coupling between two circuits is seriously affected; at the same time, the positive sequence, negative sequence and zero sequence Impedance assumes that the line is completely symmetrical, so there is a large error in simulating the actual asymmetrical line

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