CN-121076700-B - RCBO-oriented fault positioning distribution box control method and system

CN121076700BCN 121076700 BCN121076700 BCN 121076700BCN-121076700-B

Abstract

The invention discloses a fault location distribution box control method and system for RCBO, which belong to the technical field of intelligent power distribution and fault diagnosis in the field of electrical engineering, and comprise the following steps of S1, collecting three-phase current signals and residual current signals of a power distribution system, S2, calculating harmonic distortion rate and load unbalance degree based on the three-phase current signals, S3, calculating residual current waveform complexity index based on the residual current signals, S4, combining the harmonic distortion rate, the load unbalance degree, the residual current waveform complexity index and a preset basic threshold value to generate a self-adaptive threshold value, S5, selecting one of a plurality of preset fault judgment modes according to the numerical value of the residual current waveform complexity index, S6, adopting the selected fault judgment mode to process the residual current signals to generate a fault judgment result, and at least one fault judgment mode uses the self-adaptive threshold value.

Inventors

HUANG XIEYUN
ZHANG QIANG
ZHENG WEIJIAN
GONG MINGCAI
JIANG SONG
ZHOU WEN

Assignees

泰姆电气(杭州)股份有限公司

Dates

Publication Date: 20260508
Application Date: 20251104

Claims (7)

1. The fault positioning distribution box control method for the RCBO is characterized by comprising the following steps of: s1, acquiring a three-phase current signal and a residual current signal of a power distribution system; s2, calculating harmonic distortion rate and load unbalance based on the three-phase current signals; s3, calculating a residual current waveform complexity index based on the residual current signal; S4, combining the harmonic distortion rate, the load unbalance degree, the residual current waveform complexity index and a preset basic threshold value to generate an adaptive threshold value; s5, selecting one of a plurality of preset fault judging modes according to the numerical value of the residual current waveform complexity index; S6, adopting the selected fault judgment mode to process the residual current signal to generate a fault judgment result, wherein at least one fault judgment mode uses an adaptive threshold value; s7, outputting a control instruction based on a fault judgment result; s5 and S6 specifically include: when the residual current waveform complexity index is lower than a first preset threshold value, selecting a low-complexity mode, and comparing the real-time residual current amplitude with a basic threshold value in the mode; When the complexity index of the residual current waveform is larger than or equal to a first preset threshold value and smaller than or equal to a second preset threshold value, selecting a medium complexity mode, and comparing the real-time residual current amplitude with an adaptive threshold value in the mode; when the residual current waveform complexity index is higher than a second preset threshold, a high complexity mode is selected, in which mode wavelet feature matching is performed.
2. The RCBO-oriented fault location distribution box control method of claim 1, wherein S4 specifically comprises: s41, calculating a basic compensation coefficient based on the harmonic distortion rate and the load unbalance degree; s42, calculating a dynamic adjustment coefficient based on the basic compensation coefficient and the residual current waveform complexity index; s43, multiplying the basic threshold value by the dynamic adjustment coefficient to generate an adaptive threshold value.
3. The RCBO-oriented fault location distribution box control method of claim 1, wherein S3 specifically comprises: s31, carrying out wavelet packet decomposition on the residual current signal to obtain energy distribution on a plurality of frequency sub-bands; s32, calculating shannon entropy of energy distribution; And S33, carrying out normalization processing on the shannon entropy to obtain a residual current waveform complexity index.
4. The RCBO-oriented fault location distribution box control method of claim 1, wherein the wavelet feature matching specifically comprises: s61, extracting a wavelet packet energy spectrum of a residual current signal as a feature vector to be detected; S62, calculating the similarity between the feature vector to be detected and each reference vector in a preset real fault wavelet feature library; and S63, when the highest value in the similarity exceeds a preset matching confidence threshold, determining that a real fault exists.
5. The control method for the RCBO-oriented fault location distribution box according to claim 2, wherein the basic compensation coefficient is calculated through a preset basic error compensation model, and the basic compensation coefficient is in a linear positive correlation with the harmonic distortion rate and the load unbalance degree.
6. The control method for the fault location distribution box for the RCBO as claimed in claim 2, wherein the dynamic adjustment coefficient is calculated by multiplying a basic compensation coefficient by an amplification term driven by a residual current waveform complexity index.
7. The RCBO-oriented fault location block terminal control system, based on the RCBO-oriented fault location block terminal control method of any one of claims 1-6, comprising: The data acquisition module is used for acquiring three-phase current signals and residual current signals of the power distribution system; The characteristic quantization module is connected with the data acquisition module and is used for calculating harmonic distortion rate and load unbalance degree based on the three-phase current signals and calculating a residual current waveform complexity index based on the residual current signals; the dynamic compensation module is connected with the characteristic quantization module and used for generating an adaptive threshold by combining the harmonic distortion rate, the load unbalance degree, the residual current waveform complexity index and a preset basic threshold; The fault judging module is connected with the characteristic quantifying module and the dynamic compensation module, and is used for selecting a fault judging mode according to the complexity index of the residual current waveform and adopting the selected mode to process the residual current signal so as to output a control instruction.

Description

RCBO-oriented fault positioning distribution box control method and system Technical Field The invention relates to the field of intelligent power distribution and fault diagnosis in the field of electrical engineering, in particular to a fault positioning distribution box control method and system for RCBO. Background In the multi-branch parallel industrial distribution scenario with high-power nonlinear load, the traditional fault positioning method based on the residual current protector mainly depends on a fixed fault judgment threshold value. The current situation causes that the accuracy and the reliability of the method face serious challenges in a complex industrial power environment, and the current situation is particularly characterized in that current waveform distortion and three-phase load imbalance phenomenon commonly exist in a power grid, and the disturbance factors seriously interfere a fault judging mechanism of the traditional RCBO, so that the accuracy of fault positioning is reduced, misjudgment is frequently caused, non-fault tripping or missing judgment is caused, and a real fault is not detected. The fundamental reasons of the problems are that the conventional technical means are limited, a fixed threshold judgment mechanism cannot be dynamically adapted to complex electromagnetic environments caused by factors such as harmonic waves and unbalanced loads, when the intensity of background noise and interference is increased and waveforms become complex, reliability is lost only by a judgment method based on current amplitude, and as a result, under the current industrial power distribution scene, the conventional method is difficult to simultaneously ensure sensitive response to real faults and effective suppression to various electric noises, so that the overall accuracy of fault positioning is directly influenced, and the operation reliability of a power distribution system is reduced. The above information disclosed in the above background section is only for enhancement of understanding of the background of the disclosure and therefore it may include information that does not form the prior art that is already known to those of ordinary skill in the art. Disclosure of Invention The invention aims to provide a fault positioning distribution box control method and system for RCBO (resistor logic network) so as to solve the problems in the background technology. The technical scheme of the invention comprises the following steps: s1, acquiring a three-phase current signal and a residual current signal of a power distribution system; s2, calculating harmonic distortion rate and load unbalance based on the three-phase current signals; s3, calculating a residual current waveform complexity index based on the residual current signal; S4, combining the harmonic distortion rate, the load unbalance degree, the residual current waveform complexity index and a preset basic threshold value to generate an adaptive threshold value; s5, selecting one of a plurality of preset fault judging modes according to the numerical value of the residual current waveform complexity index; S6, adopting the selected fault judgment mode to process the residual current signal to generate a fault judgment result, wherein at least one fault judgment mode uses an adaptive threshold value; and S7, outputting a control instruction based on the fault judgment result. Preferably, S4 specifically includes: s41, calculating a basic compensation coefficient based on the harmonic distortion rate and the load unbalance degree; s42, calculating a dynamic adjustment coefficient based on the basic compensation coefficient and the residual current waveform complexity index; s43, multiplying the basic threshold value by the dynamic adjustment coefficient to generate an adaptive threshold value. Preferably, S3 specifically includes: s31, carrying out wavelet packet decomposition on the residual current signal to obtain energy distribution on a plurality of frequency sub-bands; s32, calculating shannon entropy of energy distribution; And S33, carrying out normalization processing on the shannon entropy to obtain a residual current waveform complexity index. Preferably, S5 and S6 specifically include: when the residual current waveform complexity index is lower than a first preset threshold value, selecting a low-complexity mode, and comparing the real-time residual current amplitude with a basic threshold value in the mode; When the complexity index of the residual current waveform is larger than or equal to a first preset threshold value and smaller than or equal to a second preset threshold value, selecting a medium complexity mode, and comparing the real-time residual current amplitude with an adaptive threshold value in the mode; when the residual current waveform complexity index is higher than a second preset threshold, a high complexity mode is selected, in which mode wavelet feature matching is performed. Preferably, the