A method for locating, isolating, and restoring localized coincident single-phase-to-ground faults

Abstract

The invention discloses a local and consistent single-phase grounding fault positioning, isolation and recovery method. The method comprises the steps of 1, starting a zero-sequence capacitance identification algorithm of a terminal to perform single-phase grounding fault diagnosis by employing a zero-sequence voltage criterion, and judging that a single-phase grounding fault occurs in a downstream when a capacitance value identified by a single-phase grounding fault detection terminal is negative and asymmetric degree of phase current abrupt exceeds a threshold; and 2, configuring a breaking-closing strategy to complete single-phase grounding fault positioning and isolation by primary and secondary matched equipment erected at a segmented switch, wherein preferably, in the step 1, single-phase grounding fault diagnosis is performed by employing a transient parameter principle and a phase current abrupt principle. Communication is not dependent, positioning and isolation of the single-phase grounding fault of a power distribution network line and power supply recovery of a non-fault region can be locally completed without protection of a circuit breaker at an exist of a substation.

Description

technical field [0001] The invention relates to a method for locating, isolating, and recovering an in-situ coincident single-phase grounding fault. Background technique [0002] Traditional single-phase ground fault automatic processing methods generally rely on information communication, such as centralized FA (feeder automation), intelligent distributed FA and other technologies. Considering the limited computing power of power distribution terminals, encryption and decryption require large computing overhead and For the problem of time overhead, the existing security protection methods cannot be embedded in centralized FA and intelligent distributed FA systems, which provides a lot of opportunities for network attacks. In addition, the basic environment of the communication network of the distribution network is also showing a trend of rapid expansion of the network attack surface, and the security defense chain is getting longer and longer, which makes the information s...

AI Technical Summary

Problems solved by technology

Voltage current time type FA considers the processing logic of single-phase ground fault, but only uses a single criterion, the fault processing time is longer and the success rate of single-phase ground fault judgment is not high

[0005] Third, according to the duality and differentiation characteristics of the single-phase ground fault current information, the fault information is sent to the main station of distribution automation for single-phase ground positioning, but this method depends on the communication and distribution automation master station

[0006] Fourth, combine the recloser and the voltage-time sectionalizer, add a single-phase grounding line selection trip function to the recloser, and realize the automatic isolation of single-phase ground faults. This method does not require the zero-sequence voltage transformer for the sectionalizer, only Single-phase grounding line selection by analyzing the characteristics of zero-sequence current is a simple strategy, but there are problems such as low judgment accuracy of single-phase grounding faults, and the exit recloser needs to be configured with multiple reclosers.

Images