Positioning method for fault section of hybrid line power distribution network based on discrete Bayesian network

Abstract

The invention provides a positioning method for a fault section of a hybrid line power distribution network based on a discrete Bayesian network, and relates to the technical field of fault diagnosis and recovery of power distribution networks. The method comprises the following steps: simplifying a physical model of a power distribution network; analyzing the influence of a line section fault on fault information in devices on two sides, and establishing a discrete Bayesian network model for fault section positioning; determining the structure of the discrete Bayesian network according to the topology of the simplified model of the power distribution network; training parameters of the discrete Bayesian network by using an expectation maximization algorithm according to historical fault information; reasoning the discrete Bayesian network by using a belief propagation algorithm to obtain probability distribution of the fault state of each line section under current observation information; and according to the fault state probability distribution of the line section, determining the line section with a fault as a fault section positioning result. According to the method, all conditions possibly occurring during a fault and the probability of the conditions can be provided, high data fault tolerance is achieved, and the problem of inaccurate fault section positioning caused by fault information distortion or missing can be effectively solved.

Description

technical field [0001] The invention relates to the field of distribution network fault diagnosis and recovery control, in particular to a method for locating a fault section of a hybrid line distribution network with fault tolerance. Background technique [0002] As the number of overhead-cable hybrid lines in the distribution network continues to increase, it is of great significance to study its fault handling technology to improve the reliability of power supply in the distribution network. As one of the commonly used technologies in fault handling, protection reclosing should not only restore the power supply in sound areas as much as possible, reduce power failure losses, but also avoid reclosing during faults, which will cause greater damage to the power distribution system after being impacted by the secondary short-circuit current. loss. Since the fault nature (transient fault / permanent fault) of overhead lines and cable lines is generally different, protection rec...

AI Technical Summary

Problems solved by technology

Judging from the current research status of distribution network fault section location, the current algorithms are all based on the assumption that the fault information collected by the distribution automation system is accurate.

However, most of the measurement devices for distribution lines are installed outdoors, which will inevitably be disturbed by various environmental factors.

These influencing factors will lead to the problem of signal distortion in the collected fault information

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