A circuit breaker just-open just-closed point online extraction method, device and medium

Abstract

The application discloses a circuit breaker just-open just-close point online extraction method and device and medium, and relates to the technical field of power equipment state monitoring and mechanical characteristic detection. The method comprises the following steps: acquiring and preprocessing the circuit breaker primary circuit opening and closing voltage and current signals collected by a non-contact sensor; for the opening process: performing continuous wavelet transform on the opening voltage signal, acquiring the frequency component of the transient recovery overvoltage, selecting a characteristic frequency, drawing a curve, and determining the occurrence time; taking the time as a reference, setting a time length, constructing a time window, performing ensemble empirical mode decomposition on the opening signal in the time window, and determining the just-open point according to the extracted IMF component; for the closing process: directly performing ensemble empirical mode decomposition on the closing signal, and extracting the just-close point according to the IMF component. The application realizes non-invasive detection, has strong environmental interference resistance, and effectively improves the precision and stability of the circuit breaker mechanical characteristic online detection through optimal selection of the characteristic frequency and the time window mechanism.

Description

Technical Field

[0001] This invention relates to the field of power equipment condition monitoring and mechanical characteristic testing technology, specifically to a method, equipment, and medium for online extraction of the contact point of a circuit breaker. Background Technology

[0002] The statements in this section are provided only as background information in relation to this disclosure and may not constitute prior art.

[0003] As a core control and protection device in a power system, the health of the mechanical characteristics of a circuit breaker directly affects the safe and stable operation of the power grid. The point at which a circuit breaker is just opened or just closed is one of the most important mechanical characteristic parameters of a circuit breaker, and the timing of its occurrence directly reflects the health of the circuit breaker's operating mechanism, linkages, contacts, and other mechanical components.

[0004] Currently, the detection methods for mechanical characteristic information of circuit breakers, such as the point of contact and opening, are mainly divided into offline detection methods and online detection methods. Offline detection methods use mechanical characteristic testers to detect information such as the point of contact and opening / closing time when the circuit breaker is de-energized. While this method provides accurate results, it is costly and cannot reflect the dynamic characteristics of the circuit breaker during operation. To compensate for the shortcomings of offline detection, existing online detection methods mostly extract features based on the current signals, vibration signals, and displacement signals of the opening and closing coils. However, due to the complex electromagnetic environment at the circuit breaker operating site, these conventional online detection methods generally suffer from prominent problems such as unclear characteristic signals and significant susceptibility to environmental interference. Therefore, there is an urgent need for an online extraction method with strong anti-interference capabilities and high detection accuracy. Summary of the Invention

[0005] The purpose of this invention is to address the problems of high cost and inability to reflect dynamic characteristics in current offline detection methods for circuit breaker mechanical characteristics, and the significant environmental influence and unclear characteristic signals in existing online detection methods. This invention provides an online extraction method, device, and medium for the rigid opening and closing points of circuit breakers. Based on non-contact sensors, the voltage and current signals of the primary circuit of the circuit breaker's opening and closing are acquired. A feature extraction algorithm that integrates continuous wavelet transform (CWT) and ensemble empirical mode decomposition (EEMD) is employed to achieve high-precision, non-invasive online detection of the rigid opening and closing points of circuit breakers.

[0006] The technical solution of the present invention is as follows: A method for online extraction of the contact point of a circuit breaker, comprising: The circuit breaker primary circuit's opening and closing voltage signal, opening current signal, closing voltage signal, and closing current signal are acquired through a non-contact sensor, and the opening voltage signal, opening current signal, closing voltage signal, and closing current signal are respectively subjected to smoothing filtering preprocessing. For the circuit breaker tripping process: perform continuous wavelet transform on the preprocessed tripping voltage signal to obtain the frequency components of the transient recovery overvoltage (TRV) period, and select characteristic frequencies from the frequency components to plot the corresponding amplitude-time curves to determine the occurrence time of the transient recovery overvoltage. Based on the occurrence time, a time window is constructed by backtracking for a set duration. Within the time window, the preprocessed tripping voltage signal and tripping current signal are subjected to ensemble empirical mode decomposition to obtain the corresponding intrinsic mode function (IMF) components. The rigid tripping point of the circuit breaker is then extracted based on the IMF components. For the circuit breaker closing process: directly perform ensemble empirical mode decomposition on the preprocessed closing voltage signal and closing current signal to obtain the corresponding IMF components, and extract the rigid closing point of the circuit breaker based on the IMF components corresponding to the closing process.

[0007] Furthermore, a continuous wavelet transform is performed on the preprocessed trip voltage signal, specifically including: The tripping voltage signal is processed using the Morlet wavelet as the mother wavelet and the following continuous wavelet transform formula:

[0008] In the formula: This represents the result of a continuous wavelet transform. This refers to the preprocessed tripping voltage signal; It is a time variable; This is a scaling parameter used to control the stretching of the wave and is inversely proportional to the output frequency. These are translation parameters used to control movement along the time axis; is the complex conjugate of the mother wavelet.

[0009] Furthermore, characteristic frequencies are selected from the frequency components to plot the corresponding amplitude-time curves, in order to determine the occurrence time of the transient recovery overvoltage, specifically including: The frequency range of the transient recovery overvoltage (TRV) period is determined to be from 1000 Hz to 15000 Hz. Select 10000Hz as the characteristic frequency and plot the corresponding amplitude-time curve; Extract the inflection point of the main peak in the amplitude-time curve, and determine the time corresponding to the inflection point as the occurrence time of the transient recovery overvoltage.

[0010] Furthermore, based on the stated occurrence time, a time window is constructed by retrospectively calculating a set duration, including: The moment of occurrence of the transient recovery overvoltage Based on this, backtrack for a duration of The time window for building is The time window.

[0011] Further, the circuit breaker's break point is extracted based on the IMF components, specifically including: Within the time window, identify the IMF components of each layer obtained after decomposing the trip voltage signal and the trip current signal; The points where waveform abrupt changes occur in the IMF components are extracted and used as the break points of the circuit breaker.

[0012] Furthermore, the rigid closing point of the circuit breaker is extracted based on the IMF component corresponding to the closing process, specifically including: By combining the original closing voltage signal and closing current signal, in the transient process corresponding to the closing process, the sharp inflection point in the last IMF component is determined as the rigid closing point of the circuit breaker.

[0013] Furthermore, non-contact sensors include non-contact electric field-voltage sensors and TMR current sensors.

[0014] Furthermore, the circuit breaker's primary circuit opening and closing signals, including the opening voltage signal, opening current signal, closing voltage signal, and closing current signal, are acquired via non-contact sensors, including: The non-contact electric field-voltage sensor collects the opening voltage signal and closing voltage signal of the primary circuit of the circuit breaker. The TMR current sensor collects the opening current signal and closing current signal of the primary circuit of the circuit breaker.

[0015] The present invention also proposes an electronic device, comprising: At least one processor; and a memory communicatively connected to said at least one processor; The memory stores instructions that can be executed by the at least one processor, and the at least one processor executes the instructions stored in the memory to perform the method described above.

[0016] The present invention also proposes a computer-readable storage medium for storing instructions that, when executed, cause the method described above to be implemented.

[0017] Compared with existing technologies, the advantages of this invention are: 1. Non-invasive high-precision detection. This invention uses non-contact electric field-voltage sensors and TMR current sensors to collect the primary circuit electrical signals of the circuit breaker, achieving non-contact signal detection without damaging the original wiring, greatly reducing the impact on the original circuit; and based on the transient electrical signals of the primary circuit opening and closing, feature extraction is performed, resulting in clear signal characteristics and minimal environmental influence, even in fully enclosed generator outlet circuit breaker scenarios.

[0018] 2. Precise location of tripping features, overcoming computational redundancy. This invention creatively employs Continuous Wavelet Transform (CWT) to locate the transient recovery overvoltage (TRV) moment, and uses this as a benchmark to construct a time window for EEMD decomposition. This mechanism avoids the massive computational burden of global signal decomposition and accurately covers the minute waveform abrupt changes caused by the time difference between TRV and the tripping point, greatly improving the sensitivity of tripping point capture.

[0019] 3. Optimized characteristic frequency, overcoming the bottleneck of waveform submersion technology. This invention, through extensive experimental verification, has locked 10000Hz as the characteristic frequency for the TRV period, effectively overcoming the problems of inaccurate capture caused by the smoothing of the main peak's initial part and the submersion of the starting point when using 5000Hz or 15000Hz. This makes the starting point of the main peak in the amplitude-time curve appear as an inflection point that is extremely easy to capture, compressing the detection error in the time dimension to the extreme (error at the level of only 0.065ms).

[0020] 4. Improved efficiency in closing feature extraction. Taking into account the relatively weak transient fluctuations during pre-breakdown during closing, this invention eliminates complex benchmark positioning during the closing process, directly using EEMD decomposition to find the final high-frequency oscillation endpoint (sharp inflection point). This makes the algorithm architecture simpler and more efficient, and highly consistent with physical phenomena. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 A flowchart for online extraction of the just-opening and just-closing points of a circuit breaker based on non-invasive voltage and current detection, provided in an embodiment of the present invention; Figure 2 This is a timing diagram of the circuit breaker opening and closing process provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the electrical signal characteristics before and after the circuit breaker trips, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the electrical signal characteristics before and after the circuit breaker's rigid closing point, provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of a non-intrusive online detection platform for the opening and closing characteristics of circuit breakers provided in an embodiment of the present invention; Figure 6a This is a waveform diagram of the circuit breaker tripping voltage and current provided in an embodiment of the present invention; Figure 6b This is a waveform diagram of the voltage and current of a circuit breaker closing during an embodiment of the present invention; Figure 7 The amplitude-time curves of the trip voltage signal CWT at three frequencies after decomposition when cosφ=0.3 are provided for embodiments of the present invention. Figure 8 The amplitude-time curves of the trip voltage signal CWT at three frequencies after decomposition under the operating condition cosφ=0.5 are provided for embodiments of the present invention. Figure 9 The amplitude-time curves of the trip voltage signal CWT at three frequencies after decomposition when cosφ=0.7 are provided for embodiments of the present invention. Figure 10 An EEMD decomposition diagram of the tripping voltage signal provided in an embodiment of the present invention; Figure 11 An EEMD decomposition diagram of the tripping current signal provided in an embodiment of the present invention; Figure 12 An EEMD decomposition diagram of the closing voltage signal provided in an embodiment of the present invention; Figure 13 The EEMD decomposition diagram of the closing current signal provided in the embodiment of the present invention.

[0023] Figure 14 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0024] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0025] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0026] Example 1 This embodiment provides an online extraction method for the point of contact and breakout of a circuit breaker, aiming to solve the technical problems of existing offline detection methods being costly and unable to reflect dynamic characteristics, as well as existing online detection methods (such as coil current, vibration signals, etc.) being greatly affected by the environment and having unclear characteristics.

[0027] Before delving into the algorithm logic of this embodiment, we first analyze the theoretical mechanism of the mechanical and electrical processes of circuit breaker opening and closing, referring to the accompanying drawings. This is the physical basis for the algorithm design of this invention: (1) Regarding the circuit breaker tripping process: Please refer to Figure 2 The circuit breaker opening and closing process timing diagram shown is as follows: Figure 3 The diagram shows the electrical signal characteristics before and after the circuit breaker just opens. During the opening process, arc reignition occurs, accompanied by high-frequency transient electrical signals. Specifically, the instant the moving and stationary contacts begin to separate after the opening signal is issued is the "just-opening point" (e.g., ...). Figure 3 (As shown at point A in the diagram). At the moment of separation, the arc-extinguishing medium is broken down to form a high-temperature plasma arc. Due to the voltage drop of the arc, the voltage between the contacts at the point of separation gradually increases from 0, and the current exhibits a slight distortion with a decrease in amplitude. Simultaneously, the voltage at the point of separation also experiences a small abrupt increase in amplitude. As the distance between the contacts increases, the arc resistance increases, and the current decreases rapidly until it is cut off, dropping sharply to 0. This point is the current-cutting point (as shown in the diagram). Figure 3 (As shown at point B in the diagram). At this point, the voltage rises sharply, generating a transient recovery overvoltage (TRV). The subsequent process is a game between TRV and dielectric recovery voltage. When TRV rises above the dielectric recovery voltage, the insulating dielectric breaks down, the voltage drops sharply to 0, a high-frequency current is generated, and the arc is generated again. The above process repeats until the arc no longer reignites.

[0028] (2) Regarding the circuit breaker closing process: Please refer to Figure 4 The diagram shows the electrical signal characteristics before and after the circuit breaker's closing point. During the closing process, a pre-breakdown phenomenon may occur when the moving and stationary contacts approach each other (e.g., Figure 4 As shown at point D in the diagram), the arc-extinguishing medium is prematurely broken down. Due to the relatively small energy reserve of the system, the pre-breakdown is not as noticeable as the restoring effect after the circuit breaker is opened. When the moving and stationary contacts are extremely close but not physically in contact, the extremely high electric field strength leads to the formation of a micro-discharge channel, resulting in a weak, high-frequency spike with a low amplitude in the current waveform. At the instant of pre-breakdown, the voltage between the contacts drops instantaneously from the power supply voltage to the arc voltage and fluctuates around the arc voltage until it reaches the point of contact (e.g., the point of contact where the circuit breaker just closes). Figure 4As shown at point E in the diagram, the voltage between the contacts stabilizes at a level close to zero. Current only begins to flow steadily at the "just-closed point" where the contacts actually make contact.

[0029] Based on the rigorous mechanism analysis described above, the overall implementation idea of ​​the method provided in this embodiment is as follows: Figure 1 As shown, the specific steps include: Step S101: Acquire the opening voltage signal, opening current signal, closing voltage signal, and closing current signal of the primary circuit of the circuit breaker through a non-contact sensor, and perform smoothing filtering preprocessing on the opening voltage signal, the opening current signal, the closing voltage signal, and the closing current signal respectively.

[0030] Specifically, the non-contact sensors include non-contact electric field-voltage sensors and TMR (tunneling magnetoresistive) current sensors. To achieve the above signal acquisition, this embodiment constructs as follows... Figure 5 The circuit breaker's opening and closing characteristics are shown in the non-intrusive online testing platform. In the test platform setup, one side of the circuit breaker is connected to a power supply, and the other side is connected to an adjustable load cell (RLC) to simulate opening and closing tests under different load sizes and power factors. Step S101 specifically includes: The non-contact electric field-voltage sensor acquires the opening and closing voltage signals of the primary circuit of the circuit breaker; the TMR current sensor acquires the opening and closing current signals of the primary circuit of the circuit breaker. After acquiring the above sensor signals, the corresponding voltage and current sensor waveforms (e.g., ...) are acquired by a data acquisition instrument. Figure 6a The waveforms of the tripping voltage and current and Figure 6b The closing voltage and current waveforms are shown below, and the waveforms are transmitted to the processing terminal for smoothing and filtering preprocessing to remove background noise. The use of non-contact detection methods not only reduces the impact on the original circuit but also minimizes damage to the circuit breaker body, making it widely applicable.

[0031] Step S102: For the circuit breaker tripping process: Perform continuous wavelet transform on the preprocessed tripping voltage signal to obtain the frequency components of the transient recovery overvoltage (TRV) period, and select characteristic frequencies from the frequency components to plot the corresponding amplitude-time curves to determine the occurrence time of the transient recovery overvoltage.

[0032] Specifically, the Morlet wavelet is used as the mother wavelet, and the tripping voltage signal is processed using the following continuous wavelet transform formula:

[0033] In the formula: This represents the result of a continuous wavelet transform. This refers to the preprocessed tripping voltage signal; It is a time variable; This is a scaling parameter used to control the stretching of the wave and is inversely proportional to the output frequency. These are translation parameters used to control movement along the time axis; is the complex conjugate of the mother wavelet.

[0034] This invention uses Morlet wavelets, which are extremely suitable for analyzing non-stationary high-frequency transient TRV signals generated when a circuit breaker trips.

[0035] Furthermore, in order to accurately pinpoint the time of TRV occurrence, the specific process includes: The frequency range of the transient recovery overvoltage (TRV) period is determined to be from 1000Hz to 15000Hz; 10000Hz is selected as the characteristic frequency to plot the corresponding amplitude-time curve; the inflection point of the main peak in the amplitude-time curve is extracted, and the time corresponding to the inflection point is determined as the occurrence time of the transient recovery overvoltage.

[0036] In specific experimental verification (e.g., using a certain type of SF6 circuit breaker as an example, with only phase B power connected), analysis of test results under seven different operating conditions revealed that the frequency range of the TRV period is concentrated in the range of [1000Hz, 15000Hz]. Please refer to [link / reference needed]. Figure 7 (Operating condition cosφ=0.3) Figure 8 (Working condition cosφ=0.5) and Figure 9 The amplitude-time curves of the trip voltage signal CWT at three frequencies are shown (cosφ=0.7 under operating condition). This embodiment explores the three frequencies of 5000Hz, 10000Hz, and 15000Hz in detail. Comparison reveals that the amplitude-time curves at 5000Hz and 15000Hz both exhibit a smoothing of the main peak's initial portion, resulting in the initial point being submerged and leading to inaccurate capture of the TRV timing. However, when the characteristic frequency is selected as 10000Hz, the starting point of the main peak in the amplitude-time curve exhibits an easily captureable "inflection point." Therefore, locking onto 10000Hz and extracting this inflection point significantly improves the detection accuracy of the TRV occurrence timing.

[0037] Step S103: Based on the occurrence time, construct a time window by backtracking a set duration. Within the time window, perform ensemble empirical mode decomposition on the preprocessed tripping voltage signal and tripping current signal to obtain the corresponding intrinsic mode function (IMF) components. Extract the tripping point of the circuit breaker based on the IMF components.

[0038] Specifically, based on the occurrence time of the transient recovery overvoltage, a time window of 0.7ms is constructed by looking back 0.7ms. Within the stated time window, ensemble empirical mode decomposition (EEMD) is used to identify the IMF components of the decomposed trip voltage signal and trip current signal. See also... Figure 10 The diagram shows the EEMD decomposition of the trip voltage signal, and... Figure 11 The diagram shows the EEMD decomposition of the tripping current signal. As described in the previous mechanism analysis, the contact gap breaks down at the point of tripping, inevitably causing a small waveform change in voltage and current. This can be analyzed by extracting the points in the IMF component where the waveform change occurs (e.g., ...). Figure 10 and Figure 11 The location marked as the "rigid break point" is used as the rigid break point of the circuit breaker. This method of "first locating the TRV and then backtracking the time window to perform EEMD" avoids the huge computational load brought by global signal processing while ensuring that the tiny abrupt change at the rigid break point is never missed.

[0039] Step S104: For the closing process of the circuit breaker: directly perform ensemble empirical mode decomposition on the preprocessed closing voltage signal and closing current signal to obtain the corresponding IMF components, and extract the rigid closing point of the circuit breaker based on the IMF components corresponding to the closing process.

[0040] Specifically, since the transient fluctuations (pre-breakdown phenomenon) in the closing electrical signal are far less pronounced than those in the opening reignition signal, there is no need to use wavelet transform to find the reference point; therefore, EEMD is directly used for decomposition. Please refer to [link to relevant documentation]. Figure 12 The EEMD decomposition diagram of the closing voltage signal shown is as follows: Figure 13 The diagram shows the EEMD decomposition of the closing current signal. Specifically, it includes: combining the original closing voltage signal and the closing current signal, and in the transient process corresponding to the closing process, determining the sharp inflection point in the last appearing IMF component as the rigid closing point of the circuit breaker (e.g., ...). Figure 12 and Figure 13 (The location of the "point of perfect coincidence" marked in the middle).

[0041] According to physical principles, at the point of contact (the instant when the moving and stationary contacts actually make physical contact), the transient fluctuation essentially ends, the voltage quickly stabilizes to near zero, and the current begins to flow steadily at the power frequency. Although there are still some fluctuations in the electrical signal for a very short time after contact, the fluctuations are small and quickly enter a stable state. Therefore, the end point of the high-frequency oscillation that appears at the end of the closing transient process (i.e., the sharp inflection point in the IMF component) corresponds to the mechanical physical contact point. Experimental verification shows that the contact point time extracted through this embodiment is 356.635ms, which is only 0.065ms different from the offline test result of 356.7ms obtained by using a high-precision mechanical characteristic tester under the circuit breaker de-energized state. This fully demonstrates that the extraction method of this invention has extremely high accuracy and stability.

[0042] Based on the same technical concept, embodiments of the present invention also provide an electronic device that can implement the online extraction method for the rigid opening and closing points of a circuit breaker provided in the above embodiments of the present invention. In one embodiment, the electronic device can be a server, a terminal device, or other electronic equipment. Figure 14 As shown, the electronic device may include: At least one processor and a memory connected to the at least one processor. In this embodiment of the invention, the specific connection medium between the processor and the memory is not limited. Figure 14 The example used is the connection between the processor and memory via a bus. The bus... Figure 14 The connections between other components are indicated by thick lines and are for illustrative purposes only, not as limiting information. Buses can be divided into address buses, data buses, control buses, etc., but for ease of representation, [the specific bus type is not shown here]. Figure 14 The processor is represented by a single thick line, but this does not imply that there is only one bus or one type of bus. Alternatively, a processor can also be called a controller; there are no restrictions on the name.

[0043] In this embodiment of the invention, the memory stores instructions executable by at least one processor. By executing the instructions stored in the memory, the at least one processor can perform the online extraction method for the rigid opening and closing points of a circuit breaker, as described above. The processor can implement... Figure 14 The functions of each module in the device shown.

[0044] The processor is the control center of the device. It can connect to various parts of the control device through various interfaces and lines. By running or executing instructions stored in memory and calling data stored in memory, it can monitor the device's various functions and process data, thereby enabling overall monitoring of the device.

[0045] In an alternative design, the processor may include one or more processing units. The processor may integrate an application processor and a modem processor, wherein the application processor primarily handles the operating system, user interface, and applications, while the modem processor primarily handles wireless communication. It is understood that the modem processor may also not be integrated into the processor. In some embodiments, the processor and memory may be implemented on the same chip; in some embodiments, they may also be implemented separately on separate chips.

[0046] The processor can be a general-purpose processor, such as a CPU, digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the online extraction method for the just-opening and just-closing points of a circuit breaker disclosed in the embodiments of this invention can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor.

[0047] Memory, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory can include at least one type of storage medium, such as flash memory, hard disk, multimedia cards, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), and electrically erasable programmable read-only memory (EPROM). Only memory (EEPROM), magnetic storage, magnetic disks, optical disks, etc. A memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures, and accessible by a computer, but is not limited thereto. The memory in embodiments of this invention can also be a circuit or any other device capable of performing storage functions for storing program instructions and / or data.

[0048] By designing and programming the processor, the code corresponding to the online extraction method for the circuit breaker's instantaneous opening and closing points described in the foregoing embodiments can be embedded into the chip, enabling the chip to execute the steps of the method described in the foregoing embodiments during operation. How to design and program the processor is a technique well-known to those skilled in the art and will not be elaborated upon here.

[0049] Based on the same inventive concept, embodiments of the present invention also provide a storage medium storing computer instructions, which, when executed on a computer, cause the computer to perform the online extraction method for the just-opening and just-closing points of a circuit breaker as described above.

[0050] In some alternative embodiments, the present invention also provides a method for online extraction of the rigid opening and closing points of a circuit breaker, which can also be implemented in the form of a program product including program code. When the program product is run on a device, the program code is used to cause the control device to perform the steps in the online extraction method for the rigid opening and closing points of a circuit breaker according to various exemplary embodiments of the present invention as described above.

[0051] It should be noted that although several units or sub-units of the apparatus have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the invention, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units. Furthermore, although the operation of the method of the invention is described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0052] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can be implemented in one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs) containing computer-usable program code. The form of a computer program product implemented on ROM, optical memory, etc.

[0053] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a server, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0054] Program code for performing the operations of this invention can be written using any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0055] In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0058] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0059] This background section is provided to generally present the context of the invention. The work of the currently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither expressly nor impliedly acknowledged as prior art to the invention.

Claims

1. A method for online extraction of the contact point of a circuit breaker, characterized in that, include: The circuit breaker primary circuit's opening and closing voltage signal, opening current signal, closing voltage signal, and closing current signal are acquired through a non-contact sensor, and the opening voltage signal, opening current signal, closing voltage signal, and closing current signal are respectively subjected to smoothing filtering preprocessing. For the circuit breaker tripping process: perform continuous wavelet transform on the preprocessed tripping voltage signal to obtain the frequency components of the transient recovery overvoltage (TRV) period, and select characteristic frequencies from the frequency components to plot the corresponding amplitude-time curves to determine the occurrence time of the transient recovery overvoltage. Based on the occurrence time, a time window is constructed by backtracking for a set duration. Within the time window, the preprocessed tripping voltage signal and tripping current signal are subjected to ensemble empirical mode decomposition to obtain the corresponding intrinsic mode function (IMF) components. The rigid tripping point of the circuit breaker is then extracted based on the IMF components. For the circuit breaker closing process: directly perform ensemble empirical mode decomposition on the preprocessed closing voltage signal and closing current signal to obtain the corresponding IMF components, and extract the rigid closing point of the circuit breaker based on the IMF components corresponding to the closing process.

2. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, The preprocessed trip voltage signal is subjected to continuous wavelet transform, specifically including: The tripping voltage signal is processed using the Morlet wavelet as the mother wavelet and the following continuous wavelet transform formula: In the formula, This represents the result of a continuous wavelet transform. This refers to the preprocessed tripping voltage signal; It is a time variable; This is a scaling parameter used to control the stretching of the wave and is inversely proportional to the output frequency. These are translation parameters used to control movement along the time axis; is the complex conjugate of the mother wavelet.

3. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, Selecting characteristic frequencies from the frequency components and plotting the corresponding amplitude-time curves to determine the occurrence time of transient recovery overvoltage, specifically including: The frequency range of the transient recovery overvoltage (TRV) period is determined to be from 1000 Hz to 15000 Hz. Select 10000Hz as the characteristic frequency and plot the corresponding amplitude-time curve; Extract the inflection point of the main peak in the amplitude-time curve, and determine the time corresponding to the inflection point as the occurrence time of the transient recovery overvoltage.

4. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, Based on the time of occurrence, a time window is constructed by retrospectively calculating a set duration, including: The moment of occurrence of the transient recovery overvoltage Based on this, backtrack for a duration of The time window for building is The time window.

5. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, Extracting the break point of the circuit breaker based on the IMF components specifically includes: Within the time window, identify the IMF components of each layer obtained after decomposing the trip voltage signal and the trip current signal; The points where waveform abrupt changes occur in the IMF components are extracted and used as the break points of the circuit breaker.

6. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, The rigid closing point of the circuit breaker is extracted based on the IMF component corresponding to the closing process, specifically including: By combining the original closing voltage signal and closing current signal, in the transient process corresponding to the closing process, the sharp inflection point in the last IMF component is determined as the rigid closing point of the circuit breaker.

7. The method for online extraction of the contact point of a circuit breaker as described in claim 1, characterized in that, Non-contact sensors include non-contact electric field-voltage sensors and TMR current sensors.

8. The method for online extraction of the contact point of a circuit breaker as described in claim 7, characterized in that, Acquire the opening voltage signal, opening current signal, closing voltage signal, and closing current signal of the primary circuit of the circuit breaker through non-contact sensors, including: The non-contact electric field-voltage sensor collects the opening voltage signal and closing voltage signal of the primary circuit of the circuit breaker. The TMR current sensor collects the opening current signal and closing current signal of the primary circuit of the circuit breaker.

9. An electronic device, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores instructions executable by the at least one processor, which executes the instructions stored in the memory to perform the method as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store instructions that, when executed, cause the method as described in any one of claims 1-8 to be implemented.

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