Distribution network single-phase grounding section positioning method based on fault phase voltage and current abrupt change

Abstract

The invention provides a distribution network single-phase grounding section positioning method based on fault phase voltage and current abrupt change. Fault phase voltage and current of each line section are measured, the phase with lower phase voltage is determined to be the fault phase, and the higher phase voltage is determined to be the sound phase. Under a certain frequency band, the fault phase current abrupt change of the downstream of the fault point of a fault wire and a sound wire is in positive correlation to the derivative of the phase voltage abrupt change, with the correlation coefficient greater than zero. The fault phase current abrupt change of the upstream of the fault point of the fault wire is in negative correlation to the derivative of the phase voltage abrupt change, with the correlation coefficient smaller than zero. The section positioning can be realized by determining the correlation coefficient between the phase current abrupt change and the derivative of the phase voltage abrupt change of each section. The method overcomes the defect that a conventional distribution network single-phase grounding section can be positioned through communication. No communication is needed, and the method is of a bootstrapping method and can solve the problem of positioning single-phase grounding section of a power distribution network.

Description

technical field [0001] The invention relates to the field of relay protection of power systems, in particular to a positioning method for a single-phase grounded section of a distribution network. Background technique [0002] The distribution network has a high probability of single-phase-to-earth faults. When a single-phase ground fault occurs in the distribution network, the line voltage between the three phases is still symmetrical, and the fault current is small, which will not affect the power supply of the load, and there is no need to trip immediately. The regulations stipulate that it can continue to run for 1-2h, but in order not to cause Fault expansion requires the ability to select the fault line and locate the faulty section to eliminate the fault as soon as possible. This problem has not been well resolved all the time. With the construction of my country's smart grid, the intelligent construction of the distribution network, as a link directly connected wit...

AI Technical Summary

Problems solved by technology

At present, the positioning method of the single-phase grounding section of the distribution network basically depends on the realization of communication, so it cannot be applied to actual projects on a large scale.

Images