Multi-sensor fusion circuit breaker just-open-just-close point monitoring method, device and equipment

Abstract

The invention discloses a multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method, device and equipment, and the method comprises the steps: obtaining a vibration signal of a contact of a circuit breaker, and determining a first just-opening and just-closing point; obtaining the current of an electromagnet coil of the circuit breaker, and determining a second just-open-just-close point; obtaining the opening and closing angular displacement of the main shaft of the circuit breaker, and determining a third just-opening and just-closing point; self-adaptive weighted fusion is carried out on the first, second and third just-open and just-close points, and just-open and just-close moments are obtained; and comparing the just-opening and just-closing moment with calibration data of the circuit breaker, and giving an alarm if a difference value exceeds a drift threshold value. According to the invention, the change process of the circuit breaker can be monitored, and the accuracy of just-open-just-close point judgment is improved.

Description

Technical Field

[0001] The present invention belongs to the field of monitoring high-voltage equipment in power systems, and relates to monitoring and displaying just-opening and just-closing points of SF6 circuit breaker contacts, and in particular to a multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method, device and equipment. Background Art

[0002] High-voltage circuit breakers are the most important switchgear in power systems. They can open and close normal lines and faulty lines, and are mainly used to automatically cut off the short-circuit current of the system when a short-circuit fault occurs in the power system. High-voltage circuit breakers consist of three parts: the breaking part, the operating and transmission part, and the insulating part. The operating mechanism is mainly used to accurately close and open the circuit breaker, and the judgment of the just-opening and just-closing points plays a key role in the monitoring of its mechanical characteristics. The mechanical characteristics measurement of existing circuit breakers is mainly the quality inspection at the factory, and the mechanical state of the circuit breaker in field operation is difficult to judge. The measurement of the just-opening and just-closing points of the existing operating circuit breakers is mainly judged by the electrical quantity of the line, and the pre-breakdown and reignition caused by high current and high voltage and the contact ablation caused by frequent breaking operations will affect the measurement of the actual just-opening and just-closing points of the circuit breaker, thereby affecting the monitoring of the mechanical characteristics of the circuit breaker.

[0003] The existing technical methods generally use the secondary AC current collected by the current transformer when the circuit breaker is in operation, record the AC current data set of any phase among phases A, B and C, calculate the circuit breaker operation threshold, and determine whether the circuit breaker is in the open or closed state at this moment, so as to determine the just-open and just-closed points. Collect data from the acceleration sensor on the insulating pull rod of the circuit breaker, and perform denoising on the acceleration data. Obtain the acceleration curve data, integrate the acceleration curve data, obtain the moving contact displacement curve data, perform feature extraction on the acceleration curve data, obtain the just-closed and just-open positions, and use the just-closed position, just-open position, moving contact speed curve data and moving contact displacement curve data to determine the monitoring data, and output the monitoring data. The physical data of a single sensor is relatively easy to offset and difficult to correct, resulting in poor measurement of just-open and just-closed points.

[0004] In addition, as the most important switchgear in the power system, the stability and accuracy of the action characteristics of high-voltage circuit breakers are directly related to the safe operation of the entire power grid system. At present, domestic circuit breakers are regularly inspected and maintained by offline routine tests and operations. This planned preventive maintenance is blind, and frequent operation and disassembly will affect the reliability of circuit breakers. Real-time monitoring of the just-open and just-close points is very necessary.

[0005] In summary, the prior art has the following problems:

[0006] First, in the prior art, changes in the external environment have a significant impact on the operating characteristics of the circuit breaker. The data collected on site is used only, but not compared with the data when the circuit breaker leaves the factory, which lacks monitoring of the circuit breaker change process.

[0007] Second, the data from a single sensor may be affected by factors such as sensor quality, aging corrosion, and temperature drift, resulting in sensor data distortion and defects. Summary of the invention

[0008] The purpose of the present invention is to provide a multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method, device and equipment, which can realize the monitoring of the circuit breaker change process and improve the accuracy of the just-opening and just-closing point judgment.

[0009] In order to achieve the above object, the solution of the present invention is:

[0010] A multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method, comprising:

[0011] Obtain the vibration signal of the circuit breaker contact and determine the first just-opening and just-closing point;

[0012] Obtain the current of the circuit breaker electromagnet coil and determine the second opening and closing point;

[0013] Obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third opening and closing point;

[0014] Adaptively weighted fusion is performed on the first to third just-break and just-close points to obtain just-break and just-close moments;

[0015] The opening and closing moments are compared with calibration data of the circuit breaker, and an alarm is issued if the difference exceeds a drift threshold.

[0016] The step of obtaining the vibration signal of the circuit breaker contact and determining the first just-opening and just-closing point includes:

[0017] The vibration signal of the circuit breaker contact is obtained by using a vibration sensor arranged on the frame side of the circuit breaker operating system;

[0018] Performing a short-time Fourier transform on the vibration signal to extract a vibration extraction time corresponding to the vibration signal that meets a vibration threshold range;

[0019] Based on the vibration extraction time and adding the fixed time difference, the circuit breaker opening and closing time is obtained, which is the first opening and closing point.

[0020] Wherein, performing short-time Fourier transform on the vibration signal includes:

[0021] The vibration signal is pre-processed to subtract the DC component before closing and eliminate the zero drift; and then a short-time Fourier transform is performed.

[0022] The method of obtaining the current of the circuit breaker electromagnet coil and determining the second rigid opening and closing point includes:

[0023] The current sensor connected to the circuit breaker opening and closing coil is used to collect the current of the electromagnet coil;

[0024] Obtain the moment when the electromagnet coil circuit suddenly changes from 0 to non-0, which is the second just-opening and just-closing point.

[0025] Among them, obtaining the opening and closing angular displacement of the main shaft of the circuit breaker and determining the third rigid opening and closing point include:

[0026] The angular displacement sensor disposed on the main shaft of the circuit breaker is used to obtain the opening and closing angular displacement of the main shaft of the circuit breaker;

[0027] Based on the opening and closing angular displacement, a closing and opening angular displacement-time curve is drawn, thereby obtaining a moving contact-time characteristic curve;

[0028] According to the moving contact-time characteristic curve, the moment when the moving contact begins to accelerate after being subjected to force is obtained, which is the third just-opening and just-closing point.

[0029] The first to third just-break and just-close points are adaptively weighted fused to obtain just-break and just-close moments, including:

[0030] Determine the weight ρ of the first-third rigid separation and combination points i =α i +β i ; The weight ρ i Including weighting factor α i and weighting factor β i , i=1,2,3 correspond to the first and third rigid separation and combination points respectively, in, Determined by the inherent error of the data acquisition device corresponding to the i-th rigid separation and combination point, Determined by the historical sampling data error of the data acquisition device corresponding to the i-th rigid separation and combination point;

[0031] Based on the weight ρ i Perform weighted fusion on the first and third rigid separation and combination points, T 01 ,T 02 ,T 03 They represent the first to third opening and closing points respectively, and obtain the opening and closing moments of the circuit breaker.

[0032] A multi-sensor fusion circuit breaker just-opening and just-closing point monitoring device, comprising:

[0033] A first just-opening and just-closing point determination module is configured to obtain a vibration signal of a circuit breaker contact and determine a first just-opening and just-closing point;

[0034] A second just-opening and just-closing point determination module is configured to obtain the current of the circuit breaker electromagnet coil and determine the second just-opening and just-closing point;

[0035] A third rigid opening and closing point determination module is configured to obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third rigid opening and closing point;

[0036] a just-opening and just-closing moment acquisition module, configured to perform adaptive weighted fusion on the first to third just-opening and just-closing points to acquire the just-opening and just-closing moments of the circuit breaker;

[0037] An analysis module is configured to compare the opening and closing moments with calibration data of the circuit breaker to obtain a difference; and

[0038] The alarm module is configured to generate an alarm when the difference exceeds a drift threshold.

[0039] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the steps of the circuit breaker just-opening and just-closing point monitoring method with multi-sensor fusion as described above are implemented.

[0040] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the steps of the circuit breaker just-opening and just-closing point monitoring method using multi-sensor fusion are implemented as described above.

[0041] After adopting the above scheme, compared with the prior art, the present invention integrates multiple physical quantity data of multiple sensors, and can obtain the just-opening and just-closing moments through data preprocessing and adaptive weighted fusion. The present invention integrates historical data, factory tests and sensor deviations, and systematically structures the system through corresponding hardware and software structures, achieving the effect of eliminating the time-space environment error, making the judgment of just-opening and just-closing points more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the circuit breaker arc extinguishing chamber structure;

[0043] Figure 2 It is the relationship between the closing current of the circuit breaker and the contact displacement;

[0044] Figure 3 It is the relationship between the circuit breaker opening current and the contact displacement;

[0045] Figure 4 is the relationship between contact displacement and time;

[0046] Figure 5 It is the hardware structure of a multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method. DETAILED DESCRIPTION

[0047] The technical solutions and beneficial effects of the present invention will be described in detail below with reference to the accompanying drawings.

[0048] The present invention provides a method for monitoring the just-opening and just-closing points of a circuit breaker by using multi-sensor fusion. The method comprehensively processes a variety of physical data of circuit breaker contacts monitored by a variety of sensors, performs preprocessing and correlation analysis, and obtains the just-opening and just-closing moments of the circuit breaker through adaptive weighted fusion. The just-opening and just-closing moments are compared with the calibration data of the circuit breaker when it leaves the factory to determine the degree of drift of the just-opening and just-closing moments, and generates an alarm if the drift degree exceeds a threshold.

[0049] The power transmission process of the contact can be regarded as: the elastic potential energy of the disc spring - the pressure kinetic energy of the hydraulic oil - the mechanical energy of the push rod. The entire power transmission system involves the conversion of various energies, and the change of the state of the contact is affected by many factors. When the external control circuit sends a closing / opening signal, the closing / opening solenoid valve is energized, the disc spring releases the elastic potential energy, and the hydraulic oil pressure increases to give the push rod mechanical energy through the valve control system, pushing the contact to move.

[0050] like Figure 1 As shown, the circuit breaker used in the present invention has an arc extinguishing chamber that is a compressed air type arc extinguishing chamber, which is mainly composed of a compressed air cylinder, a moving arc contact, a moving main contact, a nozzle, a static arc contact, and a static main contact. Closing process: The moving contact is closed from the initial open state, the distance from the static contact is reduced, and the field strength between the contacts increases. When a certain distance is reached, a pre-breakdown occurs, and an arc is generated between the moving contact and the static contact; since the arc contact contact stroke is greater than the main contact, the arc contact contacts first when closing the circuit, which is the contact just closing point, and the current is carried by the contact, and the pre-breakdown arc is extinguished. Normal load current or short-circuit fault current flows on the main contact. Opening process: The contact moves to open under the drive of the operating mechanism, the SF6 gas in the compressed air chamber begins to be compressed, the main contact just separates, and the current is transferred from the main contact to the arc contact, and then the static contact and the moving contact separate, which is the just opening point.

[0051] During the long-term use of the circuit breaker, the overtravel will change due to contact wear, loose screws and other reasons, and it is very difficult to determine the moment when the circuit breaker just opens and closes. The traditional measurement of the just-opening and just-closing point is equivalent to the voltage and current changes in the main circuit of the circuit breaker. However, due to the excessive voltage and current in the high-voltage line, the pre-breakdown and restrike of the arc will occur during the process of the moving and static contacts approaching and moving away, resulting in a mismatch between the electrical change and the just-opening and just-closing moment of the contact, which needs to be monitored based on other physical quantities. Therefore, in this embodiment, a variety of sensors are placed on the mechanism connected to the contacts, and the change process of the contacts is indirectly monitored by processing the sensor data.

[0052] In this embodiment, a vibration sensor is placed on the frame side of the circuit breaker operating system, and the rigid opening and closing points of the contacts are analyzed by monitoring and analyzing the vibration when the mechanical parts connected to the contacts collide. This vibration sensor is a high-performance broadband single-axis MEMS vibration sensor, which is a sensor made using the piezoresistive effect of single-crystal silicon material and integrated circuit technology. When a single-crystal silicon material is subjected to force, its resistivity changes, and an electrical signal output proportional to the force change can be obtained through the measurement circuit. The output signal is an analog voltage signal, which integrates a signal modulation circuit, a demodulation amplifier, an output amplifier, and a sensor through MEMS technology. The output voltage signal is pre-processed, and can be directly sampled and converted into analog to digital, simplifying the subsequent signal conditioning circuit.

[0053] In this embodiment, the current sensor is placed at the electromagnet coil of the circuit breaker's opening and closing solenoid valve, and the change in the current of the tripping electromagnet coil can be analyzed to analyze the just-opening and just-closing points. This sensor is a through-core sensor, which converts the large current on the primary side into a small current on the secondary side for measurement based on the principle of electromagnetic induction. It consists of a closed iron core and a winding. Its primary side winding has very few turns and is connected in series in the circuit of the current to be measured. Under normal working conditions, the voltage drop on the primary and secondary windings is very small, which is equivalent to a transformer in a short-circuit state, so the magnetic flux in the iron core is very small. This is because the magnetic potential of the primary and secondary windings is equal in magnitude and opposite in direction. And the current ratio between the first and second current transformers is inversely proportional to the number of turns of the primary and secondary windings.

[0054] In this embodiment, the angular displacement sensor is installed on the main shaft of the circuit breaker, and the opening and closing angular displacement-time curve of the main shaft of the circuit breaker is measured to obtain the moving contact-time characteristics. The linear motion relationship between the insulating pull rod of the circuit breaker and the main shaft and the moving contact can be derived from the mechanical design drawing of the circuit breaker. The working principle of the angular displacement is to use a specially shaped rotor and a winding coil to model the linear displacement of the linear differential sensor, which has high reliability and performance. The rotational motion of the rotor shaft generates a linear output signal around the factory preset zero displacement of ±60 (a total of 120) degrees. The phase of this output signal indicates the displacement direction away from the zero position. The non-contact electromagnetic coupling of the rotor gives the product infinite resolution, that is, the absolute measurement accuracy can reach a few tenths of a degree.

[0055] The present invention also provides a multi-sensor fusion circuit breaker just-opening and just-closing point monitoring device, comprising:

[0056] A first just-opening and just-closing point determination module is configured to obtain a vibration signal of a circuit breaker contact and determine a first just-opening and just-closing point;

[0057] A second just-opening and just-closing point determination module is configured to obtain the current of the circuit breaker electromagnet coil and determine the second just-opening and just-closing point;

[0058] A third rigid opening and closing point determination module is configured to obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third rigid opening and closing point;

[0059] a just-opening and just-closing moment acquisition module, configured to perform adaptive weighted fusion on the first to third just-opening and just-closing points to acquire the just-opening and just-closing moments of the circuit breaker;

[0060] An analysis module is configured to compare the opening and closing moments with calibration data of the circuit breaker to obtain a difference; and

[0061] The alarm module is configured to generate an alarm when the difference exceeds a drift threshold.

[0062] like Figure 5As shown, the partial structure of the monitoring device is schematically shown, wherein the data acquisition module includes three data acquisition devices, which are respectively used to obtain the vibration signal of the circuit breaker contact, the current of the circuit breaker electromagnet coil, and the opening and closing angular displacement of the circuit breaker main shaft. In this embodiment, the three sensors are respectively used to collect the above data, reflecting the circuit breaker contact information, the display module displays the operating status of the circuit breaker contact, and the alarm module is connected to the data acquisition module through the communication interface. Specifically, each sensor converts the collected analog signal through the acquisition channel into a signal between 0-5V through the level conversion circuit, passes through the AD conversion module, and the digital signal output after conversion needs to be converted into a 3.3V digital signal, sent to the signal processing module, and transmitted to the host computer through RS485 communication. The host computer performs a large amount of data analysis, determines the moment of the circuit breaker contact just opening and closing, and displays the result on the display. If the threshold is exceeded, the alarm module works.

[0063] In this embodiment, the data processing function in the data acquisition module is divided into five layers, namely, the sensor layer, the data layer, the data access layer, the business logic layer and the user application layer. The sensor layer is equipped with data acquisition sensor hardware facilities on the circuit breaker contact connection mechanism. The lower computer receives the data collected by the sensor through A / D acquisition or serial communication. After the lower computer completes the acquisition, the upper computer software connects with the lower computer software through the network interface, and transfers the data saved in the lower computer buffer to the upper computer software for processing; the data layer uses MySQL database and CSV files for storage. The MySQL database mainly stores various information data generated in the system, and the CSV file is mainly used to store a large amount of fault data detected; the data access layer is responsible for accessing the MySQL database to realize the addition, deletion, modification and query of database data; the business logic layer interacts with the equipment of the sensor layer according to the business logic of the data acquisition module to collect real-time data of the contact and process the collected data; the user application layer provides specific services for users. This module is connected to the display module and the alarm module. The state of the contact will be displayed to the user in the form of a time domain spectrum diagram, etc. If the threshold is exceeded, an alarm will be issued to remind the user.

[0064] There is a large amount of noise interference in the data acquisition process of the vibration sensor. Most of the noise values ​​in the time domain are small, and there are large noise impacts at a few moments. Squaring the superimposed signal can highlight the vibration signal with larger energy, and the noise impact with smaller value will also be weakened due to the superposition of energy. Before using the short-time Fourier transform to process the signal, the vibration signal should be preprocessed. The DC component before closing the circuit breaker is subtracted from the collected vibration signal, thereby eliminating the DC component in the collected vibration signal and eliminating the zero drift.

[0065] The vibration sensor data is transformed using short-time Fourier transform In the formula, x k is the vibration signal of the vibration sensor, ω k is a real window sequence. When k takes different values, the window ω(km) slides to different positions along the time axis, and different vibration signals are taken out for Fourier transform. Obviously, the short-time Fourier transform is a function of time k and angular frequency ω, which reflects the characteristics of the frequency spectrum of the vibration signal changing with time.

[0066] The process of judging the vibration signal and the just-opening and just-closing point is as follows: without changing the overtravel, a large number of experiments are carried out at the same position to collect data, and the values ​​corresponding to the curve of the vibration signal after short-time Fourier transformation at the moment of sudden change of the transposition signal are recorded. These arrays constitute a threshold range. In subsequent experiments, it is written into the algorithm, and the vibration characteristic curve is obtained after short-time Fourier transformation. As time goes by, when a vibration value meets this threshold range, the time corresponding to this vibration value is extracted, and the starting time T of the circuit breaker contact opening and closing corresponding to the vibration signal can be obtained. The time T is added with the first time difference ΔT to obtain the first just-opening and just-closing point; wherein, the first time difference ΔT is the inherent time difference between the vibration signal extraction time T and the transposition signal sending time T′, and ΔT=TT′. The vibration signal characteristics and inherent time difference obtained from the relationship between the vibration signal and the contact change in online monitoring are used as the original data of the data layer.

[0067] The change of the circuit breaker coil current is related to the mechanical characteristics of the circuit breaker, mainly including: opening and closing time, opening and closing speed, contact opening distance, overtravel, opening and closing synchronization and closing bounce time. The current sensor monitors the solenoid valve current in real time, and takes the moment when the solenoid valve current changes from 0 to non-0 (mutation moment) as the second just-opening and just-closing point; in this embodiment, in order to facilitate measurement, the moment when the solenoid valve current changes from 0 to 0.1A can be set as the second just-opening and just-closing point.

[0068] The relationship between the change of solenoid valve current and the change of contact is as follows Figure 2 and Figure 3 shown. Figure 2 In the figure, A1 is the moment when the closing coil starts to be energized, B1 is the moment when the closing contact starts to move, and C1 is the just-closed point. The measured closing time T H =T C1 -T A1 , the opening distance is d, the action time is ΔT H =T C1 -T B1 , the average closing speed V can be obtained H =d / ΔT H . Figure 3In the figure, A2 is the moment when the opening coil starts to be energized, B2 is the moment when the contact starts to move when the opening is performed, C2 is the opening point, and D2 is the opening end position, which is the reference point for calculating the opening speed. The opening time T is measured. F =T C2 -T A1 , action time ΔT F =T D2 -T C2 , the average opening speed V can be obtained F =d / ΔT H .

[0069] The relationship between the contact displacement and time collected by the angular displacement sensor is as follows: Figure 4 As shown. This moving contact-time characteristic curve can be divided into four stages, namely, the idle travel section S1, the open distance section S2, the overtravel section S3 and the buffer section S4. These four stages reflect the moving contact in different motion states and stress states. The idle travel section refers to the movement of the moving contact before it is subjected to force. The end time of this stage is T0. The open distance section refers to the situation where the moving contact begins to accelerate after being thrust. The end time of this stage is T1, which is the third just-opening and just-closing point. The overtravel section refers to the situation where the moving contact begins to decelerate after reaching the maximum speed. The end time of this process is T2. The buffer section refers to the situation where the moving contact decelerates due to the hydraulic buffer when it is close to rest. The end time of this process is T3. The just-opening and just-closing moments are obtained according to the events T0, T1, T2, and T3 corresponding to each stage.

[0070] The data collected from each sensor mentioned above have different characteristics after preprocessing and sorting, and the points of contact opening and closing obtained have different characteristics. In order to accurately realize the state description of the contact movement process, we should make full use of multiple sensor information resources, and through reasonable combination of multiple information, combine the complementary and redundant parts of multi-sensor information under specific regulations from the perspective of time and space to produce information fusion results, so as to achieve a consistent description of the moment when the contacts just open and close.

[0071] The fusion of the above-mentioned multiple sensors is a fusion of the feature layer. The first to third just-opening and just-closing points are obtained according to the data processing collected by each sensor. At the same time, the variance is obtained according to the inherent error of the sensor and the historical data, and the just-opening and just-closing moments are obtained by adaptive weighted fusion. Specifically, the three characteristic quantities of the first to third just-opening and just-closing points derived from the characteristic signals extracted in the real-time operation of the three sensors of the above-mentioned vibration sensor, current sensor and angular displacement sensor are weightedly fused with the three characteristic quantities measured by the mechanical characteristic instrument used by the manufacturer before the circuit breaker leaves the factory, and the three characteristic quantities extracted from the historical monitoring operation data of the circuit breaker to obtain the just-opening and just-closing moments, and then compared with the closing and closing time calibrated by the circuit breaker manufacturer. When the absolute value of the difference between the two is less than the drift threshold, it is considered that the circuit breaker performance meets the requirements, otherwise it is considered that the accuracy and stability of the circuit breaker action need to be adjusted, and an alarm signal is issued; in this embodiment, the drift threshold can be set to 1ms.

[0072] In this embodiment, the specific implementation process of the above adaptive weighted fusion of the first to third rigid separation and combination points is as follows: Assume that the variance of each sensor is n represents different sensors, n = 1, 2, 3, respectively representing vibration sensor, current sensor, angular displacement sensor, α n Represents the weighting factor of each sensor according to its inherent error, so the value after the fusion of each sensor measurement Total variance for weighted fusion The minimum value of the multivariate quadratic function of the weighting factor is the minimum total variance, that is, According to the extreme value theory of multivariate function, the corresponding weighting factor when the total variance is minimum is: At this time, the total variance is The sensors in operation are estimated by the mean of historical data, i.e. m represents the number of historical sampling points, and the total variance of the sensor is Among them, β i is the weighting factor obtained by each sensor based on the error of historical sampling data. The optimal weighting factor is The optimal weight of each sensor is The moment when the circuit breaker just opens and closes is T 01 ,T 02 ,T 03 Represent the first to third just-opening and just-closing points respectively. The inherent error of the sensor is retested every time the circuit breaker is overhauled. During the operation, as the historical data increases, the optimal weighting factor changes, the error will gradually decrease, and the final just-opening and just-closing moment will be adaptively adjusted.

[0073] An embodiment of the present invention further provides another computer device, including a processor and a memory configured to store a computer program that can be run on the processor; wherein, when the processor is configured to run the computer program, the method steps in the aforementioned embodiment are executed.

[0074] In practical applications, the processor includes a field programmable gate array (FPGA), and the processor may be a central processing unit (CPU) or a digital signal processor (DSP). It is understandable that for different devices, the electronic device used to implement the function of the processor may be other, and the embodiment of the present invention does not specifically limit it.

[0075] The above-mentioned memory can be a volatile memory (volatile memory), such as a random access memory (RAM); or a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory, a hard disk (HDD) or a solid-state drive (SSD); or a combination of the above-mentioned types of memory, and provide instructions and data to the processor.

[0076] In an exemplary embodiment, an embodiment of the present invention further provides a computer-readable storage medium for storing a computer program.

[0077] Optionally, the computer-readable storage medium can be applied to any one of the methods in the embodiments of the present invention, and the computer program enables the computer to execute the corresponding processes implemented by the processor in each method in the embodiments of the present invention. For the sake of brevity, they are not described here.

[0078] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0079] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0080] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0081] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0082] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0083] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0084] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A multi-sensor fusion circuit breaker just-opening and just-closing point monitoring method, characterized by: include, Obtain the vibration signal of the circuit breaker contact and determine the first just-opening and just-closing point; Obtain the current of the circuit breaker electromagnet coil and determine the second opening and closing point; Obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third opening and closing point; Adaptively weighted fusion is performed on the first to third just-break and just-close points to obtain just-break and just-close moments; The opening and closing moments are compared with calibration data of the circuit breaker, and an alarm is issued if the difference exceeds a drift threshold.

2. The method according to claim 1, characterized in that: Obtain the vibration signal of the circuit breaker contact and determine the first just-opening and just-closing point, including: The vibration signal of the circuit breaker contact is obtained by using a vibration sensor arranged on the frame side of the circuit breaker operating system; Performing a short-time Fourier transform on the vibration signal to extract a vibration extraction time corresponding to the vibration signal that meets a vibration threshold range; The circuit breaker opening and closing moment is obtained based on the vibration extraction moment, which is the first just-opening and just-closing point.

3. The method according to claim 2, characterized in that: Performing a short-time Fourier transform on the vibration signal includes: The vibration signal is pre-processed to subtract the DC component before closing and eliminate the zero drift; and then a short-time Fourier transform is performed.

4. The method according to claim 1, characterized in that: Obtain the circuit breaker electromagnet coil current and determine the second opening and closing point, including: The current sensor connected to the circuit breaker opening and closing coil is used to collect the current of the electromagnet coil; Obtain the moment when the electromagnet coil circuit suddenly changes from 0 to non-0, which is the second just-opening and just-closing point.

5. The method according to claim 1, characterized in that: Obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third opening and closing point, including: The angular displacement sensor disposed on the main shaft of the circuit breaker is used to obtain the opening and closing angular displacement of the main shaft of the circuit breaker; Based on the opening and closing angular displacement, a closing and opening angular displacement-time curve is drawn, thereby obtaining a moving contact-time characteristic curve; According to the moving contact-time characteristic curve, the moment when the moving contact begins to accelerate after being subjected to force is obtained, which is the third just-opening and just-closing point.

6. The method according to claim 1, characterized in that: Adaptively weighted fusion is performed on the first to third just-break and just-close points to obtain just-break and just-close moments, including: Determine the weight ρ of the first-third rigid separation and combination points i =α i +β i ; The weight ρ i Including weighting factor α i and weighting factor β i , i=1, 2, 3 correspond to the first to third rigid separation and combination points respectively, in, Determined by the inherent error of the data acquisition device corresponding to the i-th rigid separation and combination point, Determined by the historical sampling data error of the data acquisition device corresponding to the i-th rigid separation and combination point; Based on the weight pi, the first and third rigid separation and combination points are weightedly fused. T 01 , T 02 , T 03 They represent the first to third opening and closing points respectively, and obtain the opening and closing moments of the circuit breaker.

7. A multi-sensor fusion circuit breaker just-opening and just-closing point monitoring device, characterized in that: include, A first just-opening and just-closing point determination module is configured to obtain a vibration signal of a circuit breaker contact and determine a first just-opening and just-closing point; A second just-opening and just-closing point determination module is configured to obtain the current of the circuit breaker electromagnet coil and determine the second just-opening and just-closing point; A third rigid opening and closing point determination module is configured to obtain the opening and closing angular displacement of the circuit breaker main shaft and determine the third rigid opening and closing point; a just-opening and just-closing moment acquisition module, configured to perform adaptive weighted fusion on the first to third just-opening and just-closing points to acquire the just-opening and just-closing moments of the circuit breaker; An analysis module is configured to compare the opening and closing moments with calibration data of the circuit breaker to obtain a difference; as well as, The alarm module is configured to generate an alarm when the difference exceeds a drift threshold.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, the steps of the method for monitoring the circuit breaker just-opening and just-closing points by multi-sensor fusion as described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by a processor, the steps of the method for monitoring circuit breaker just-opening and just-closing points using multi-sensor fusion are implemented as described in any one of claims 1 to 6.

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