Single-phase earth fault rapid linear calculation method applied to unbalanced distribution network

Abstract

The invention discloses a single-phase earth fault rapid linear calculation method applied to an unbalanced distribution network. Based on the thought of a sequence component method, compensation is performed on asymmetric elements by the adoption of a controlled power source on the basis of using symmetrical component transformation, and meanwhile a phase shift process under different fault phases is simplified. Through the processing, a composite sequence network model suitable for single-phase earth fault calculation of the unbalanced distribution network can be obtained, and the model cancontinue to be simplified into a seven-node simplified linear calculation model. By use of the seven-node simplified calculation model, positive sequence voltages, negative sequence voltages and zerosequence voltages of substation buses and fault ports can be calculated, a positive sequence current, a negative sequence current and a zero sequence current of each feeder are calculated according tothe positive sequence voltages, the negative sequence voltages and the zero sequence voltages, and therefore single-phase earth fault calculation on the unbalanced distribution network is realized. Through the method, the calculation process of solving a single-phase earth fault of the unbalanced distribution network is greatly simplified, low-dimensional linear solving is realized, and calculation speed is increased.

Description

technical field [0001] The invention relates to the field of distribution networks, in particular to a fast linear calculation method for single-phase grounding faults used in unbalanced distribution networks. Background technique [0002] Unlike high-voltage grids, unbalance is one of the main characteristics of distribution grids. When the traditional symmetric component method is applied to symmetrical components, the parameter matrix in the sequence coordinate system obtained after the parameter matrix in the phase coordinate system is transformed by the symmetric component will be a diagonal matrix, so that the positive sequence, negative sequence and zero sequence The networks will be independent of each other, bringing great convenience to computing. However, when the traditional symmetric components are applied to asymmetric components, the parameter matrix under the order coordinates will no longer be a diagonal matrix, so there will be a coupling relationship betw...

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Problems solved by technology

[0005] In order to solve the problems of low calculation accuracy, complex calculation process and large calculation scale in unbalanced distribution network single-phase ground fault calculation, the present invention provides a single-phase ground fault fast linear calculation method for unbalanced distribution network

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