CN-121984243-A - Intelligent switching-on and switching-off method and system of reclosing circuit breaker based on electromagnet

CN121984243ACN 121984243 ACN121984243 ACN 121984243ACN-121984243-A

Abstract

The invention discloses an intelligent opening and closing method and system of a reclosing circuit breaker based on an electromagnet, and relates to the field of intelligent control. And after the brake is separated, a first delay stage is carried out, the states of the circuit breaker and the circuit are comprehensively evaluated, and a dynamic weight index system is constructed to calculate an evaluation score. And if the score exceeds the threshold value, closing after the time delay is finished, otherwise, triggering an alarm. And after closing, entering a second delay stage, continuously monitoring the electric parameters and establishing an abnormality judgment mechanism to form a closed loop protection flow of monitoring, opening, evaluating, closing and re-monitoring, thereby realizing the intelligent linkage of overcurrent protection and state self-adaption. The circuit breaker accurate switching-on/off control method has the advantages that through real-time monitoring of circuit electric parameters, multidimensional state evaluation and intelligent decision mechanism, accurate switching-on/off of the circuit breaker is realized, power supply reliability is improved, fault power failure time is reduced, and misoperation risk is reduced.

Inventors

ZHANG XIAOYAN
ZHANG YAN
SHI JUN
ZHAO WEI
GAO SHENG
TAN XINDONG

Assignees

国网山西省电力有限公司朔州供电分公司

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. The intelligent switching-on and switching-off method of the reclosing circuit breaker based on the electromagnet is characterized by comprising the following steps of: Continuously acquiring and monitoring line electric parameters of a line connected with the circuit breaker, dynamically comparing line current data acquired in real time with a preset current threshold value, judging overcurrent abnormality, and triggering opening operation; After the opening operation is finished, the breaker automatically enters a first delay stage, and multidimensional state comprehensive analysis is carried out on the starting breaker and the circuit; based on the comprehensive analysis result of the multidimensional state, constructing a multidimensional evaluation index system of the breaker state, calculating an evaluation score through a weighted summation algorithm, and dynamically adjusting the weight of each index according to the current operation condition of the circuit; establishing a threshold judgment mechanism of the evaluation score, comparing the evaluation score obtained by calculation with a preset score threshold, if the evaluation score is larger than the preset score threshold, performing closing operation after the first delay stage is finished, otherwise triggering fault alarm; After the closing operation is finished, the circuit breaker automatically enters a second delay stage, and an electrical parameter abnormality judgment mechanism of the second delay stage is established by collecting the electrical parameters of the circuit in real time.
2. The intelligent opening and closing method of the electromagnet-based reclosing circuit breaker according to claim 1, wherein the continuously collecting and monitoring the line electrical parameters of the line connected with the circuit breaker, dynamically comparing the line current data collected in real time with a preset current threshold value, judging the overcurrent abnormality, and triggering the opening operation specifically comprises: The line electrical parameters comprise line current, line voltage, power factor, three-phase current unbalance degree and voltage harmonic total distortion rate; collecting rated working current and non-permanent fault current of a line in the past 3 months, and calculating a preset current threshold value by combining the real-time environment temperature; Comparing the acquired real-time current with a preset current threshold value, and judging that the overcurrent is abnormal if the current exceeds the threshold value; Based on the condition of judging overcurrent abnormality, immediately sending a brake separating signal to the electromagnet driving module to drive the breaker operating mechanism to act, so that the movable contact and the static contact are separated, and the circuit is disconnected.
3. The intelligent opening and closing method of the electromagnet-based reclosing circuit breaker according to claim 1, wherein the circuit breaker automatically enters a first delay stage after the opening operation is completed, and the multi-dimensional state comprehensive analysis of the starting circuit breaker and the circuit specifically comprises the following steps: the initial duration of the first delay stage is 5 seconds, and in the first delay stage, a multidimensional state comprehensive analysis flow of the circuit breaker and the circuit is started, and the method comprises the following steps: carrying out full-period current characteristic analysis on the monitored line current data, and judging the fault type and the fault severity of the line; Monitoring the residual voltage of the line in real time, and judging whether the residual voltage accords with the voltage condition of normal switching-on of the line; And executing omnibearing state self-detection on the electromagnet driving module, and judging whether the coil, the driving loop and the iron core structure of the electromagnet driving module are in a normal working state or not.
4. The intelligent opening and closing method of the reclosing circuit breaker based on the electromagnet according to claim 3, wherein the performing full-period current feature analysis on the monitored line current data, judging the fault type and the fault severity of the line specifically comprises: performing wavelet transformation on the current data by using a db4 wavelet basis function, decomposing to obtain a high-frequency detail coefficient and a low-frequency approximation coefficient, and extracting a transient current peak value, a current rising rate and a transient duration time through the high-frequency coefficient; Performing fast Fourier transform on the split-gate current data, converting a time domain signal into a frequency domain signal, and calculating a steady-state current effective value, a current harmonic total distortion rate and a harmonic component amplitude; Sequentially integrating the extracted transient current peak value, current rising rate, transient duration, steady-state current effective value, current harmonic total distortion rate and harmonic component amplitude as a fault feature matrix; and calling a pre-trained fault identification model, inputting a fault feature matrix into the model, and outputting a fault type preliminary judgment result and a fault severity degree by comparing sample features of a training stage.
5. The intelligent opening and closing method of the reclosing circuit breaker based on the electromagnet according to claim 3, wherein the real-time monitoring of the residual voltage of the line and the judgment of whether the residual voltage meets the voltage condition of normal closing of the line specifically comprise: after the opening operation is finished, recording residual voltage amplitude data through a high-precision voltage sensor, continuously acquiring, calculating an average value, and calculating residual voltage frequency through a time interval of 2 adjacent voltage zero crossing points; based on the acquired voltage amplitude data, performing linear fitting by adopting a least square method, acquiring a fitting straight line of the voltage amplitude changing along with time, and recording the moment as voltage recovery stabilizing time when the fluctuation amplitude of the continuous voltage amplitude is less than 2% of rated voltage; Based on the voltage standard of normal switching-on of the line, judging whether the average value of the residual voltage is in the fluctuation range of rated voltage, judging whether the voltage frequency is in the fluctuation range of standard power frequency, judging whether the voltage recovery rate is positive, if all the voltage recovery rates are met, judging that the residual voltage meets the switching-on condition, and if not, judging that the residual voltage does not meet the switching-on condition.
6. The intelligent opening and closing method of the reclosing circuit breaker based on the electromagnet according to claim 3, wherein the performing the omnibearing state self-check on the electromagnet driving module, judging whether the coil, the driving circuit and the iron core structure of the electromagnet driving module are in a normal working state specifically comprises: After the opening operation is finished and the first delay stage is started, triggering the electromagnet driving module to perform self-checking, measuring the voltage at two ends of the coil and calculating a direct current resistance value according to ohm law by introducing constant direct current into the electromagnet coil, and judging that the coil is normal if the resistance value is within a preset normal range and judging that the coil is aged or has turn-to-turn short circuit if the resistance value exceeds the preset normal range; collecting the input voltage of a driving circuit, collecting the working current of the driving circuit by a current sensor, and judging that the power supply of the driving circuit is abnormal when any parameter exceeds the range; the displacement sensor monitors the whole action process of the electromagnet iron core in real time, records the maximum stroke and the stroke deviation, and judges the iron core clamping stagnation or the structural deformation if the maximum stroke is insufficient or the deviation exceeds a threshold value; and integrating all the detection parameters, if all the detection parameters accord with the normal range, judging that the driving module is normal, and immediately generating a fault report if any parameter is abnormal.
7. The intelligent opening and closing method of the reclosing circuit breaker based on the electromagnet according to claim 1, wherein the steps of constructing a multi-dimensional evaluation index system of the circuit breaker state based on the multi-dimensional state comprehensive analysis result, calculating an evaluation score through a weighted summation algorithm, and dynamically adjusting the weight of each index according to the current operation condition of the circuit comprise the following steps: based on analysis results of fault characteristics, residual voltage and electromagnet state, core evaluation indexes are defined as fault characteristic indexes, residual voltage indexes and electromagnet state indexes, and index assignment is carried out; determining index weights based on the current load rate and voltage of the line, and optimizing the weights by combining historical operation data through a gradient descent algorithm; and calculating the evaluation score by substituting the index assignment and the corresponding weight.
8. The intelligent opening and closing method of the electromagnet-based reclosing circuit breaker according to claim 1, wherein the establishing a threshold judgment mechanism of the evaluation score compares the evaluation score obtained by calculation with a preset score threshold, if the evaluation score is greater than the preset score threshold, the opening operation is performed after the first delay stage is finished, otherwise, the triggering of the fault alarm specifically includes: Determining a preset score threshold value based on the importance of the line, comparing the calculated evaluation score with the preset score threshold value in real time, judging that the line fault is eliminated, the voltage is compliant and the electromagnet is normal if the evaluation score is larger than or equal to the threshold value, and judging that the closing condition is not met currently if the evaluation score is smaller than the threshold value; If the switching-on condition is met, a switching-on signal is sent to the electromagnet driving module after the first delay stage is finished, the control module drives the operating mechanism to drive the moving contact to move towards the fixed contact until the contact is completely closed, and the power supply of the circuit is recovered; If the closing condition is not met, the duration of the first delay stage is prolonged, and the multi-dimensional state comprehensive analysis flow and evaluation score calculation are immediately re-executed to form a circulation evaluation; and accumulating the total duration of the first delay stage in real time, and triggering fault alarm if the total duration reaches a preset upper limit and the closing condition is not met.
9. The intelligent opening and closing method of the electromagnet-based reclosing circuit breaker according to claim 1, wherein after the closing operation is completed, the circuit breaker automatically enters a second delay stage, and the electrical parameter abnormality judgment mechanism for establishing the second delay stage by collecting the line electrical parameters in real time specifically comprises: triggering a second delay stage after the closing operation is completed, wherein the duration of the second delay stage is set to be 2 seconds, and continuously acquiring line electric parameters in the second delay stage; setting a threshold value according to the type of the electric parameter, comparing the monitoring data in real time, and judging that the line is abnormal if any parameter exceeds the threshold value; Based on the abnormal condition of the line, an acceleration switching-off signal is sent, the driving current of the electromagnet is controlled to be 1.5 times of the rated value, the arc extinguishing chamber is synchronously started to perform forced ventilation, and the arc is accelerated to extinguish; And locking a closing loop, prohibiting closing within 10 minutes, triggering audible and visual alarm, and uploading fault data.
10. The intelligent opening and closing system of the reclosing circuit breaker based on the electromagnet is used for realizing the intelligent opening and closing method of the reclosing circuit breaker based on the electromagnet as claimed in any one of claims 1 to 9, and is characterized by comprising the following steps: The module is used for collecting parameters of line current, voltage and power factor in real time, dynamically calculating a current threshold value and triggering a switching-off or switching-on decision; The module combines wavelet transformation and FFT to analyze fault characteristics, detects residual voltage and electromagnet state, and calculates comprehensive evaluation score; The intelligent switching-off and switching-on control module is used for controlling the electromagnet to execute switching-off or switching-on according to the evaluation result and dynamically adjusting the delay time; The electromagnet self-checking and driving module is used for detecting the coil resistance, the driving loop parameter and the iron core state, ensuring the reliable action of the electromagnet and triggering an alarm when the electromagnet is abnormal; the secondary protection and abnormality processing module is used for continuously monitoring electric parameters after closing, accelerating opening and forced arc extinction if abnormality occurs, and locking a closing loop to prevent misoperation; the processor is used for processing the calculation process of each formula and the construction calculation process of each model.

Description

Intelligent switching-on and switching-off method and system of reclosing circuit breaker based on electromagnet Technical Field The invention relates to the field of intelligent control, in particular to an intelligent opening and closing method and system of a reclosing circuit breaker based on an electromagnet. Background With the development of automation of smart power grids and power systems, the defects of slow response speed, large mechanical abrasion and the like of the traditional mechanical circuit breaker are increasingly remarkable, and the requirements of a modern power system on rapid and accurate opening and closing operation are difficult to meet. The reclosing circuit breaker driven by the electromagnet becomes a research hot spot due to the advantages of high response speed, high control precision, long service life and the like. However, the dynamic characteristics of the existing electromagnet breaker under the complex working condition are unstable, and an intelligent self-adaptive control strategy is lacked, so that the problems of inaccurate opening and closing time sequence, arc reburning and the like frequently occur. In the current reclosing circuit breaker opening and closing method in the market, on fault judgment, the opening and closing are triggered by a fixed current threshold value, historical data and real-time environment dynamic adjustment are not combined, and misjudgment or missed judgment is easily caused by threshold value rigidification. After the switching off, a fixed delay switching-on mode is adopted, comprehensive analysis on the fault type and the residual voltage state of the line is lacked, whether the fault disappears is judged only by simply waiting, permanent fault identification is delayed, and secondary switching-on risks are easy to cause. On the guarantee of a driving mechanism, the omnibearing self-detection of the electromagnet coil, the driving circuit and the iron core structure is less, and the switching-on and switching-off action failure is often caused by the hidden fault of the mechanism. The secondary protection mechanism is insufficient after closing, the design of short-time accurate monitoring and acceleration of opening is often omitted, the arc cannot be quickly extinguished when the fault is recovered, and the fault influence is easily enlarged. And the evaluation system adopts fixed weight, so that the load working conditions of different lines are difficult to adapt, the whole decision lacks intelligence and flexibility, and the power supply reliability and the operation safety are inferior to those of the method. Disclosure of Invention In order to perfect the existing method and system, the intelligent switching-on and switching-off method and system of the reclosing circuit breaker based on the electromagnet are provided. In order to achieve the above purpose, the invention adopts the following technical scheme: the intelligent switching-on and switching-off method of the reclosing circuit breaker based on the electromagnet comprises the following steps: Continuously acquiring and monitoring line electric parameters of a line connected with the circuit breaker, dynamically comparing line current data acquired in real time with a preset current threshold value, judging overcurrent abnormality, and triggering opening operation; After the opening operation is finished, the breaker automatically enters a first delay stage, and multidimensional state comprehensive analysis is carried out on the starting breaker and the circuit; based on the comprehensive analysis result of the multidimensional state, constructing a multidimensional evaluation index system of the breaker state, calculating an evaluation score through a weighted summation algorithm, and dynamically adjusting the weight of each index according to the current operation condition of the circuit; establishing a threshold judgment mechanism of the evaluation score, comparing the evaluation score obtained by calculation with a preset score threshold, if the evaluation score is larger than the preset score threshold, performing closing operation after the first delay stage is finished, otherwise triggering fault alarm; After the closing operation is finished, the circuit breaker automatically enters a second delay stage, and an electrical parameter abnormality judgment mechanism of the second delay stage is established by collecting the electrical parameters of the circuit in real time. Preferably, the continuously collecting and monitoring the line electrical parameter of the line connected with the circuit breaker dynamically compares the line current data collected in real time with a preset current threshold value, judges that the overcurrent is abnormal, and triggers the opening operation specifically includes: The line electrical parameters comprise line current, line voltage, power factor, three-phase current unbalance degree and voltage harmonic total distortion rate; c