Fault early warning system of power capacitor

Abstract

The invention discloses a fault early warning system of a power capacitor, relates to the technical field of capacitor fault early warning, and solves the technical problem that capacitor fault early warning is not accurate enough in the prior art. The temperature, current and voltage of the capacitor are collected in real time through the sensor, and the abnormal condition of the capacitor can be found in time; by comparing the temperature, the current and the voltage with the temperature threshold value, the current threshold value and the voltage threshold value, the fault state of the fault capacitor is obtained, the working state of the capacitor can be monitored in real time and in all directions, and the timeliness and the accuracy of fault discovery are improved; calculating a health value of the capacitor, and comparing the health value with a health threshold value; early warning can be given out when the power capacitor has an initial fault sign, potential faults can be found in advance, and the reliability and stability of a power system are improved. According to the method, the capacitor image is compared with the image of the fault-free capacitor, and the appearance state of the capacitor is obtained according to the difference.

Description

Technical Field

[0001] The invention belongs to the field of capacitor fault early warning, relates to sensor technology, and specifically is a fault early warning system for a power capacitor. Background Art

[0002] As the scale of power systems continues to expand and the technical complexity increases, power capacitors are key equipment for reactive power compensation, voltage regulation, and maintaining system power factor balance. The stability of their operating status is of vital importance to the safe and reliable operation of the entire power system. However, during long-term operation, power capacitors are prone to failures such as dielectric breakdown, overheating, bulging, oil leakage, and lead burnout due to various factors such as internal dielectric aging, overload operation, environmental pollution, and mechanical stress. If these problems are not discovered and handled in a timely manner, they may cause serious equipment damage and grid interruption.

[0003] In the prior art, in the fault warning process of power capacitors, the real-time operating status of the capacitor is not analyzed when collecting data, resulting in a lag in the inspection of the fault, which can lead to the inability to discover and handle the fault in time; and the collected data is relatively limited, which often leads to inaccurate prediction results when predicting possible faults of the capacitor.

[0004] The present invention provides a fault early warning system for a power capacitor to solve the above technical problems. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a fault warning system for a power capacitor, which is used to solve the technical problem that the capacitor fault warning in the prior art is not accurate enough; the present invention collects the temperature, current and voltage data of the power capacitor in real time through a sensor, and collects the image of the capacitor and the image of the fault-free capacitor; compares the temperature, current and voltage with the temperature threshold, current threshold and voltage threshold to obtain the fault state of the faulty capacitor, and generates a temperature fault signal, a current fault signal and a voltage fault signal according to the fault state; calculates the health value of the fault-free capacitor, and compares the health value with the health threshold to generate an abnormal signal, compares the capacitor image with the fault-free image to obtain the appearance state of the capacitor; integrates the health state and the appearance state into warning data, and maintenance personnel repair or replace the capacitor to solve the above problems.

[0006] To achieve the above-mentioned object, the first aspect of the present invention provides a fault warning system for a power capacitor, comprising: a database, a data collection module, a monitoring and analysis module and a warning processing platform;

[0007] Data collection module: collects the status data of power capacitors in real time through sensors; collects images of power capacitors through image acquisition equipment; obtains fault-free images of capacitors through database;

[0008] Monitoring and analysis module: predict the health status of the capacitor based on the status data; pre-process the capacitor image and the fault-free image to obtain the standard image and the normal image; compare the standard image with the normal image to obtain the appearance status of the capacitor; integrate the health status and the appearance status into early warning data;

[0009] Early warning processing platform: Generates early warning notifications based on early warning data, and maintenance personnel repair or replace capacitors based on the early warning notifications.

[0010] The present invention collects temperature, current and voltage data of power capacitors in real time through sensors, collects images of power capacitors through image acquisition equipment, and collects unobstructed images of capacitors through a database; compares temperature, current and voltage with temperature thresholds, current thresholds and voltage thresholds to obtain the fault state of the faulty capacitor, and generates a temperature fault signal, a current fault signal and a voltage fault signal according to the fault state; can detect in real time whether a capacitor fails, and repair the faulty capacitor in time, thereby reducing the repair and replacement costs caused by the failure, as well as the production losses that may be caused thereby; calculates the health value of a fault-free capacitor, compares the health value with the health threshold, generates an abnormal signal, compares the capacitor image with the fault-free image, and obtains the appearance state of the capacitor; can warn of capacitor failure in advance, so that maintenance personnel can maintain or replace capacitors with hidden dangers in time, thereby effectively extending the service life of the capacitor and reducing unnecessary equipment replacement costs.

[0011] Preferably, the real-time acquisition of state data of the power capacitor by a sensor includes:

[0012] The temperature data of the power capacitor is collected in real time through the temperature sensor; the current data flowing through the power capacitor is collected in real time through the current transformer; the voltage data of the power capacitor is collected in real time through the voltage transformer;

[0013] The temperature data, current data and voltage data are integrated into the status data of the power capacitor.

[0014] The present invention collects the real-time operating status data of the capacitor through the sensor and analyzes it, thereby improving the timeliness and accuracy of fault discovery.

[0015] Preferably, predicting the health status of the capacitor according to the status data includes:

[0016] Extract temperature data, current data and voltage data from the status data and mark them as Tk, Ik and Vk respectively, and set a temperature threshold Tg, a current threshold Ig and a voltage threshold Vg; wherein the temperature threshold, the current threshold and the voltage threshold are set according to the temperature, current and voltage when the historical capacitor fails;

[0017] Determine whether the temperature data is greater than a temperature threshold; if yes, mark the corresponding capacitor as being in an abnormal temperature state; if no, mark the corresponding capacitor as being in a normal temperature state;

[0018] Determine whether the current data is greater than the current threshold; if yes, mark the corresponding capacitor as being in an abnormal current state; if no, mark the corresponding capacitor as being in a normal current state;

[0019] Determine whether the voltage data is greater than a voltage threshold; if yes, mark the corresponding capacitor as being in an abnormal voltage state; if no, mark the corresponding capacitor as being in a normal voltage state;

[0020] Integrate the abnormal temperature state, abnormal current state and abnormal voltage state into a fault state; mark the capacitor in a non-fault state as a non-fault capacitor; and mark the capacitor in a fault state as a faulty capacitor;

[0021] The health value of the fault-free capacitor is calculated by the formula JKC = α × (Tg-Tk) + β × (Ig-Ik) + γ (Vg-Vk); where α, β, and γ are weight coefficients, which are set according to the influence of temperature, current, and voltage on the health of the capacitor;

[0022] The fault status and health value are marked as the health status of the capacitor.

[0023] The present invention determines whether a capacitor is faulty by setting a threshold value, so that faults can be discovered in time to avoid losses caused by continued use; the health value of a fault-free capacitor is calculated to obtain the health status of the capacitor, so that an early warning can be issued when the power capacitor shows signs of early failure, potential faults can be discovered in advance, and small problems can be prevented from developing into large failures.

[0024] Preferably, the preprocessing of the capacitor image and the fault-free image to obtain the standard image and the normal image includes:

[0025] Extract capacitor images and fault-free images;

[0026] The capacitor image and the fault-free image are processed with noise reduction, enhancement and grayscale in turn, and the preprocessed capacitor image is marked as a standard image, and the preprocessed fault-free image is marked as a normal image.

[0027] Preferably, the step of comparing the standard image with the normal image to obtain the appearance of the capacitor includes:

[0028] S1: extracting a standard image and an unobstructed image; obtaining the contours of the standard image and the unobstructed image through an edge detection algorithm, and extracting geometric features of the contours; marking the height of the capacitor in the standard image as standard height, and marking the height of the capacitor in the unobstructed image as normal height; setting a bulge threshold; wherein the bulge threshold includes a first threshold and a second threshold; the bulge threshold is set according to the degree of danger of the capacitor bulge;

[0029] S2: Determine whether the value of the standard high minus the normal high is greater than the first threshold; if yes, mark the corresponding capacitor as a first-level bulge capacitor; if no, jump to S3;

[0030] S3: Determine whether the value of the standard high minus the normal high is greater than a second threshold; if yes, mark the corresponding capacitor as a secondary bulging capacitor; if no, mark the corresponding capacitor as a normal bulging capacitor;

[0031] The primary bulging capacitor, secondary bulging capacitor and normal bulging capacitor are marked as the appearance status of the capacitor.

[0032] The present invention can effectively prevent system operation instability caused by capacitor bulging by extracting geometric features of capacitor images and calculating differences, and compare the differences with preset thresholds, thereby ensuring safe, reliable and efficient operation of the power system. Grading the different degrees of bulging helps operation and maintenance personnel to prioritize the processing order according to the severity of the bulging and perform preventive maintenance in advance.

[0033] Preferably, generating a warning notification according to the warning data includes:

[0034] Extract early warning data;

[0035] When an abnormal temperature state occurs, a temperature fault signal is generated; when an abnormal current state occurs, a current fault signal is generated; when an abnormal voltage state occurs, a voltage fault signal is generated;

[0036] Setting a health threshold; determining whether the health value of a normal capacitor is greater than the health threshold; if yes, marking the corresponding capacitor as a normal capacitor; if no, marking the corresponding capacitor as an abnormal capacitor and generating an abnormal signal; wherein the health threshold is set according to the maximum value of the health value of the faulty capacitor;

[0037] When the capacitor is a primary bulging capacitor, a primary bulging signal is generated; when the capacitor is a secondary bulging capacitor, a secondary bulging signal is generated;

[0038] The temperature fault signal, current fault signal, voltage fault signal, primary bulge signal, secondary bulge signal and abnormal signal are integrated into early warning notification.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention collects the temperature, current and voltage of the capacitor in real time through sensors, and can promptly detect abnormal conditions of the capacitor; by comparing the temperature, current and voltage with the temperature threshold, current threshold and voltage threshold, the fault state of the faulty capacitor is obtained, and the working state of the capacitor can be monitored in real time and in all directions, thereby improving the timeliness and accuracy of fault detection; the health value of the capacitor is calculated, and the health value is compared with the health threshold to determine whether the capacitor is close to failure, and an early warning can be issued when the power capacitor shows signs of early failure, thereby detecting potential failures in advance and improving the reliability and stability of the power system.

[0041] 2. The present invention compares the capacitor image with the image of a fault-free capacitor and obtains the external state of the capacitor according to the difference; the bulging condition of the capacitor can be obtained, and the health state and the external state are integrated into the early warning data of the capacitor, so as to eliminate the danger in time, reduce the maintenance and replacement costs caused by the fault, and the production losses that may be caused thereby, and at the same time optimize the maintenance plan, reduce the unplanned downtime and the investment of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 The following is a flowchart of an embodiment of the present invention.

[0044] Figure 2 It is a system composition diagram of the present invention. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] See also Figure 1-Figure 2 , the first aspect of the present invention provides a fault warning system for a power capacitor, including: a database, a data collection module, a monitoring and analysis module and a warning processing platform;

[0047] Data collection module: collects the status data of power capacitors in real time through sensors; collects images of power capacitors through image acquisition equipment; obtains fault-free images of capacitors through databases.

[0048] Exemplarily, the temperature data of the power capacitor is collected in real time by a temperature sensor set on the capacitor; the current data flowing through the power capacitor is collected in real time by a current transformer; the voltage data of the power capacitor is collected in real time by a voltage transformer; the temperature of capacitor x is obtained to be 15 degrees, the current passing through capacitor x is 0.1A, and the voltage passing through capacitor x is 1500V; the side view of capacitor x is collected by a camera; and the fault-free image of capacitor x is extracted through a database.

[0049] Monitoring and analysis module: predict the health status of the capacitor based on the status data; pre-process the capacitor image and the fault-free image to obtain the standard image and the normal image; compare the standard image with the normal image to obtain the appearance status of the capacitor; integrate the health status and the appearance status into early warning data.

[0050] For example, the temperature threshold is set to 25 degrees, the current threshold is set to 0.3A, and the voltage threshold is set to 1600V;

[0051] Determine whether the temperature data is greater than a temperature threshold; if yes, mark the corresponding capacitor as being in an abnormal temperature state; if no, mark the corresponding capacitor as being in a normal temperature state;

[0052] Determine whether the current data is greater than the current threshold; if yes, mark the corresponding capacitor as being in an abnormal current state; if no, mark the corresponding capacitor as being in a normal current state;

[0053] Determine whether the voltage data is greater than a voltage threshold; if yes, mark the corresponding capacitor as being in an abnormal voltage state; if no, mark the corresponding capacitor as being in a normal voltage state;

[0054] It is judged that capacitor x is a fault-free capacitor; the weight coefficients α=1, β=20, γ=0.1 are set, and the health value JKC=24 of capacitor x is calculated by the formula JKC=α×(Tg-Tk)+β×(Ig-Ik)+γ(Vg-Vk).

[0055] In another embodiment, if the capacitor is in at least one of an abnormal temperature state, an abnormal current state, and an abnormal voltage state, the capacitor is a faulty capacitor and a corresponding fault signal is generated.

[0056] The maximum value of the health value of the faulty capacitor is 18, and the health threshold is set to 20; determine whether the health value of the normal capacitor is greater than the health threshold; if yes, mark the corresponding capacitor as a normal capacitor; if not, mark the corresponding capacitor as an abnormal capacitor and generate an abnormal signal; determine that capacitor x is a normal capacitor.

[0057] It should be noted that the health threshold is not the health value of the faulty capacitor, but the health value of a normal capacitor close to the faulty capacitor. This setting can predict the health of the capacitor in advance and prepare for the replacement and maintenance of the capacitor in advance, thereby effectively extending the service life of the capacitor and reducing unnecessary equipment replacement costs.

[0058] The side view of capacitor x and the unobstructed image of the capacitor are subjected to noise reduction, enhancement and grayscale processing in sequence, and the preprocessed capacitor image is marked as a standard image, and the preprocessed fault-free image is marked as a normal image.

[0059] The edge detection algorithm is used to obtain the contours of the standard image and the normal image. The standard height of the capacitor in the standard image is measured to be 3.2 cm, and the normal height of the capacitor in the normal image is measured to be 3 cm. The first threshold is set to 3.1 cm and the second threshold is set to 3.3 cm.

[0060] Determine whether the value of the standard high minus the normal high is greater than the first threshold; if so, mark the corresponding capacitor as a first-level bulging capacitor; if not, continue to determine whether the value of the standard high minus the normal high is greater than the second threshold; if so, mark the corresponding capacitor as a second-level bulging capacitor; if not, mark the corresponding capacitor as a normal bulging capacitor; determine that capacitor x is a second-level bulging capacitor.

[0061] The warning data obtained is that capacitor x is a normal capacitor, a secondary bulging capacitor, and a secondary bulging signal is generated.

[0062] Early warning processing platform: Generates early warning notifications based on early warning data, and maintenance personnel repair or replace capacitors based on the early warning notifications.

[0063] Exemplarily, the secondary bulge signal is sent to a receiving end of a maintenance personnel, and the maintenance personnel repairs or replaces the capacitor x.

[0064] In another embodiment, if there are multiple bulging capacitors and warnings, the maintenance work can be prioritized according to the level of bulging.

[0065] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0066] Working principle of the present invention:

[0067] The present invention collects the temperature, current and voltage of the capacitor in real time through sensors, compares them with preset thresholds, and monitors the normal operation of the capacitor in real time; obtains the health value of the capacitor through the gap between the temperature, current and voltage and the preset thresholds, compares the health value with the health threshold, and determines whether the capacitor is close to failure; the present invention compares the image of the capacitor with the image of a normal capacitor and calculates the difference, and grades the danger level of the capacitor bulge according to the difference to obtain the appearance status of the capacitor; integrates the health status and appearance status into early warning data of the capacitor; maintenance personnel make repair or replacement plans for the capacitor in advance based on the early warning signals generated by the early warning data.

[0068] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A fault warning system for a power capacitor, characterized in that: include: Database, data collection module, monitoring and analysis module and early warning processing platform; Data collection module: collects the status data of power capacitors in real time through sensors; Collect images of power capacitors through image acquisition equipment; obtain fault-free images of capacitors through a database; Monitoring and analysis module: predict the health status of the capacitor based on the status data; pre-process the capacitor image and the fault-free image to obtain the standard image and the normal image; Compare the standard image with the normal image to obtain the appearance state of the capacitor; Integrate health status and appearance status into early warning data; Early warning processing platform: Generates early warning notifications based on early warning data, and maintenance personnel repair or replace capacitors based on the early warning notifications.

2. A power capacitor fault warning system according to claim 1, characterized in that: The real-time acquisition of state data of the power capacitor by the sensor includes: The temperature data of the power capacitor is collected in real time through the temperature sensor; the current data flowing through the power capacitor is collected in real time through the current transformer; the voltage data of the power capacitor is collected in real time through the voltage transformer; The temperature data, current data and voltage data are integrated into the status data of the power capacitor.

3. A power capacitor fault warning system according to claim 1, characterized in that: The predicting the health status of the capacitor according to the status data includes: Extract temperature data, current data and voltage data from the status data and mark them as Tk, Ik and Vk respectively, and set a temperature threshold Tg, a current threshold Ig and a voltage threshold Vg; wherein the temperature threshold, the current threshold and the voltage threshold are set according to the temperature, current and voltage when the historical capacitor fails; Determine whether the temperature data is greater than a temperature threshold; if yes, mark the corresponding capacitor as being in an abnormal temperature state; if no, mark the corresponding capacitor as being in a normal temperature state; Determine whether the current data is greater than the current threshold; if yes, mark the corresponding capacitor as being in an abnormal current state; if no, mark the corresponding capacitor as being in a normal current state; Determine whether the voltage data is greater than a voltage threshold; if yes, mark the corresponding capacitor as being in an abnormal voltage state; if no, mark the corresponding capacitor as being in a normal voltage state; Integrate the abnormal temperature state, abnormal current state and abnormal voltage state into a fault state; mark the capacitor in a non-fault state as a non-fault capacitor; and mark the capacitor in a fault state as a faulty capacitor; The health value of the fault-free capacitor is calculated by the formula JKC=α×(Tg-Tk)+β×(Ig-Ik)+γ(Vg-Vk); wherein α, β, and γ are weight coefficients.

4. A power capacitor fault warning system according to claim 1, characterized in that: The preprocessing of the capacitor image and the fault-free image to obtain the standard image and the normal image includes: Extract capacitor images and fault-free images; The capacitor image and the fault-free image are processed with noise reduction, enhancement and grayscale in turn, and the preprocessed capacitor image is marked as a standard image, and the preprocessed fault-free image is marked as a normal image.

5. A power capacitor fault warning system according to claim 1, characterized in that: The step of comparing the standard image with the normal image to obtain the appearance of the capacitor includes: S1: extracting a standard image and an unobstructed image; obtaining the contours of the standard image and the unobstructed image through an edge detection algorithm, and extracting geometric features of the contours; marking the height of the capacitor in the standard image as standard height, and marking the height of the capacitor in the unobstructed image as normal height; setting a bulge threshold; wherein the bulge threshold includes a first threshold and a second threshold; the bulge threshold is set according to the degree of danger of the capacitor bulge; S2: Determine whether the value of the standard high minus the normal high is greater than the first threshold; if yes, mark the corresponding capacitor as a first-level bulge capacitor; if no, jump to S3; S3: Determine whether the value of the standard high minus the normal high is greater than a second threshold; if yes, mark the corresponding capacitor as a secondary bulging capacitor; if no, mark the corresponding capacitor as a normal bulging capacitor; The primary bulging capacitor, secondary bulging capacitor and normal bulging capacitor are marked as the appearance status of the capacitor.

6. A power capacitor fault warning system according to claim 1, characterized in that: Generating a warning notification according to the warning data includes: Extract early warning data; When an abnormal temperature state occurs, a temperature fault signal is generated; when an abnormal current state occurs, a current fault signal is generated; when an abnormal voltage state occurs, a voltage fault signal is generated; Setting a health threshold; determining whether the health value of a normal capacitor is greater than the health threshold; if yes, marking the corresponding capacitor as a normal capacitor; if no, marking the corresponding capacitor as an abnormal capacitor and generating an abnormal signal; wherein the health threshold is set according to the maximum value of the health value of the faulty capacitor; When the capacitor is a primary bulging capacitor, a primary bulging signal is generated; when the capacitor is a secondary bulging capacitor, a secondary bulging signal is generated; The temperature fault signal, current fault signal, voltage fault signal, primary bulge signal, secondary bulge signal and abnormal signal are integrated into early warning notification.

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