Fault positioning method of power distribution network FTU (feeder terminal unit)

Abstract

The invention discloses a fault positioning method of a power distribution network FTU (feeder terminal unit). The method includes: using fault overcurrent information reported by a feeder monitoringterminal to preliminarily determine a fault section; converting the fault information of a solution into switch fault current information, and calculating a target function value; updating a harmony memory database, performing iteration, outputting an optimal solution, and converting into fault information; comparing transient-state zero-sequence currents, collected in a sampling window, of each detection point on each line at a bus outlet with a threshold Ist, if the transient-state zero-sequence current magnitude of more than 3 detection points in 5 continuous detection points is larger thanthe threshold Ist, starting the FTU, and recording the fault information; or else, continuing sampling the transient-state zero-sequence currents while the FTU is not started; performing small current grounding fault positioning according to the transient-state zero-sequence current magnitude change condition of each detection point on a selected line. The method which only utilizes transient-state zero-sequence current signals is wide in application range, simple and easy to implement.

Description

technical field [0001] The invention relates to the field of electric power, in particular to a fault location method for a distribution network FTU. Background technique [0002] Fault indicators are short circuit and ground fault indicators are devices used to detect short circuits and ground faults. In the ring network power distribution system, especially in the system that uses a large number of ring network load switches, if a short-circuit fault or a ground fault occurs in the lower-level power distribution network system, the upper-level power supply system must be repaired within the specified time. break to prevent major accidents. By using this product, it is possible to mark the part where the failure occurred. Maintenance personnel can quickly find the faulty section according to the alarm signal of this indicator, separate the faulty section, and restore the power supply of the non-faulty section in time, which can save a lot of working time and reduce the po...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that when a small current single-phase grounding fault occurs in the system, the fault current is very small and the fault signal is weak, which makes fault detection, line selection and positioning very difficult. The purpose is to provide a distribution network FTU The fault location method solves the problem that when a small current single-phase ground fault occurs in the system, the fault current is very small and the fault signal is weak, which makes fault detection, line selection, and location very difficult

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