Fault studying and judging method and device based on edge computing FTU and fault indicator

Abstract

The invention relates to the technical field of distribution automation fault research and judgment, and discloses a fault research and judgment method based on an edge calculation FTU and a fault indicator, which comprises the following steps: acquiring recording data of a plurality of cycles before a fault recording starting moment and a plurality of cycles after the fault recording starting moment, and calculating fault waveform samples collected by the FTU based on the edge calculation; a first half-wave waveform research and judgment criterion is used as a main criterion of internal and external faults, a sample waveform correlation criterion is used for checking and rechecking internal and external recording samples of a first half-wave waveform research and judgment criterion conclusion, and the first half-wave waveform research and judgment criterion is used as an auxiliary criterion of first half-wave waveform research and judgment, comprehensive research and judgment are carried out, and a position node where a single-phase earth fault occurs is determined. Compared with the prior art, the method has the advantages that the accuracy of fault detection in different single-phase earth fault environments can be improved to the greatest extent by utilizing mutual complementation and mutual verification of two research and judgment criteria.

Description

technical field [0001] The invention relates to the technical field of distribution automation fault research and judgment, in particular to a fault research and judgment method and device based on edge computing FTU and fault indicators. Background technique [0002] At present, the domestic distribution network automation application mode for overhead lines is based on the FTU as the main device and the fault indicator as the auxiliary device, both of which are connected to the distribution network automation master station at the same time. The FTU is mainly responsible for fault location and isolation, and the fault indicator is responsible for assisting fault location. There is no intercommunication and interaction between the two. Moreover, fault indicators are independently connected to the main station system at present. Because of their large number, the access workload to the main station is very large, and equipment disconnection occurs frequently, which also adds...

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Problems solved by technology

Moreover, at present, the fault indicators are independently connected to the main station system. Because of the large number, the access workload to the main station is very large, and the equipment is frequently disconnected, which also adds a lot of maintenance work

In addition, the fault indicator based on the current mutation criterion has misjudgment of the ground fault in the algorithm, and the high-precision fault indicator based on the zero-sequence voltage startup brings an increase in the number of devices and an increase in the complexity of the connection question

[0003] Today's distribution network adopts zero-sequence current for fault research and judgment accuracy, the reasons are: (1) The low-current grounding method is widely used. After a single-phase ground fault occurs, both the fault line and the normal line have zero-sequence current. It is difficult to accurately detect the method of starting the value; (2) The grounding method of the arc suppressing coil is increasing day by day, and the power direction of the zero-sequence current has changed. (3) There are many branches of the line, the structure is complex, and it is difficult to obtain accurate line parameters; (4) The single-phase grounding situation is complicated, including metallic grounding, high-resistance grounding and arc grounding, etc.

Therefore, the single-phase ground fault location method based solely on zero-sequence current cannot achieve high accuracy.

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