Monitoring device and method for monitoring a surge

Abstract

A monitoring device (10) for monitoring surges passing through a surge arrester (12) adapted to be connected to an electric power network for protecting an electrical equipment (14) of the electric power network against incoming surges passing through the surge arrester (12). The monitoring device (10) detects reignited surges caused by switching of a circuit breaker. The monitoring device (10) also counts the number of detected reignited surges.

Description

Technical Field

[0001] This invention relates to the field of surge measurement and surge arrester protection of electrical equipment. Specifically, this invention relates to a monitoring device for monitoring surges in power networks. Background Technology

[0002] Power transformers are exemplary electrical devices used in power grids. They transform voltage and current to transmit and distribute electrical energy, and are critical electrical devices for reliable power distribution within the grid. Spontaneous outages in a power network caused by failures of such critical equipment can lead to disruptions in power distribution and significant revenue losses for network operators. Additional costs are also incurred when outages are caused by damaged or faulty power network components, for which replacement and / or repair of the network components is required.

[0003] Surge arresters can be used in power networks to protect equipment from transient overvoltages caused by power surges. To enable the study of actual surges occurring at specific locations, surge arresters can be equipped with surge monitoring devices, such as surge counters.

[0004] Surge counters are used to count the number of surges occurring in a power network and discharged through a specific surge arrester. Surge counters typically count the number of surges, such as those caused by lightning and / or switching, and some surge counters also provide the magnitude of the surge. To understand surge phenomena and effectively protect electrical equipment, more information is needed from surge monitoring devices, such as the surge waveform, surge magnitude, and the patterns of occurrence and recurrence. Furthermore, this information can be used for the effective protection, condition monitoring, and diagnosis of electrical equipment (e.g., power transformers) protected by surge arresters.

[0005] During certain conditions, power surges may occur due to circuit breaker switching, such as surges caused by reignition. Re-ignition is a transient overvoltage caused by internal activity such as the switching operation of a nearby circuit breaker. Circuit breaker re-breakdown is an abnormal arcing phenomenon that can lead to potential circuit breaker failure.

[0006] This disclosure presents an improved solution for a monitoring device for surge counting, specifically for counting reignitions in a power grid. Summary of the Invention

[0007] The purpose of the embodiments described herein is to enhance surge counting in surge arresters, or at least to provide an alternative to solutions known in the art.

[0008] According to one aspect, this objective is achieved by providing a monitoring device for monitoring surges passing through a surge arrester. The surge arrester is adapted to be connected to a power grid to protect electrical equipment of the power grid from intrusive surges passing through the surge arrester. The monitoring device is adapted to detect reignition surges passing through the surge arrester. Reignition surges are caused by the switching of a circuit breaker.

[0009] According to another aspect, the aforementioned objective is also achieved by providing a method performed by a monitoring device for monitoring surges passing through a surge arrester. The surge arrester is connected to the power grid to protect electrical equipment on the power grid from intrusive surges passing through the surge arrester. The monitoring device detects reignition surges. Reignition surges are caused by the switching of a circuit breaker.

[0010] This document also provides a computer program product including instructions that, when executed on at least one processor, cause at least one processor to perform the method described above as performed by a monitoring device. Additionally, this document provides a computer-readable storage medium storing a computer program product including instructions that, when executed on at least one processor, cause at least one processor to perform the method described above as performed by a monitoring device.

[0011] The current solution is based on the understanding that by detecting reignition surges from the initial surge of a reignition surge (where the reignition surge is caused by the switching of a circuit breaker) prior to the activation of a surge arrester protecting electrical equipment from surges, the number of detected reignition surges can be calculated. Thus, the surge counting in the surge arrester is enhanced, enabling the identification and counting of reignition surges. Therefore, surge counting can be used to improve the assessment of the condition of electrical equipment protected by surge arresters and also improve the protection of electrical equipment in the power network against intrusive surges, including reignition surges.

[0012] Therefore, a monitoring device for detecting reignition surges through a surge arrester has been realized, wherein the reignition surge is caused by the switching of the circuit breaker. Attached Figure Description

[0013] Further technical features of the invention will become apparent from the following description of one or more exemplary embodiments given in the accompanying drawings, in which: Figure 1 This is a schematic overview describing a portion of a power network including monitoring devices according to some embodiments described herein; Figure 2 It is a flowchart describing a method performed by a monitoring device according to an embodiment of this document; Figure 3a and Figure 3b It is a diagram illustrating an example of the voltage and current measured from the test; Figure 4a and Figure 4b This is another diagram illustrating examples of the measured voltages and currents from the test; Figure 5a and Figure 5b This is another diagram illustrating examples of the measured voltages and currents from the test; Figure 6a and Figure 6b This is another diagram illustrating examples of the measured voltage and current from the test; and Figure 7 This is a schematic block diagram showing network nodes according to some embodiments described herein; It should be noted that the accompanying drawings are not necessarily drawn to scale, and the dimensions of some components may be enlarged for clarity. Detailed Implementation

[0014] A surge arrester is a device that protects electrical equipment in a power grid from damage, for example, from overvoltage caused by a surge. A typical surge arrester is connected between the power grid and ground, for example, to a live wire near the electrical equipment. When a surge travels through the power grid to the surge arrester, and specifically, when the voltage in the live wire reaches a certain overvoltage level due to the surge, the surge arrester allows current to be conducted from the live wire to ground by providing low resistance to the surge, thus maintaining the overvoltage level. Therefore, the electrical equipment is protected by the surge arrester and prevented from experiencing excessive overvoltage.

[0015] Figure 1 A portion of a power network, including a live wire 11 and electrical equipment 14, such as a transformer, connected to the live wire 11, is schematically shown. This portion of the power network also includes a surge arrester 12 connected to the live wire 11 to protect the electrical equipment 14 from intrusive surges in the live wire 11. The surge arrester 12 can be electrically connected to the live wire 11 by means of an electrical conductor. The surge arrester 12 can also be connected to ground via an electrical conductor. The power network may also include a circuit breaker. A monitoring device 10 is connected to the surge arrester 12 to record monitoring data related to, for example, the operation and status of the surge arrester 12.

[0016] Monitoring device 10 may include a surge counter for monitoring surges, specifically for monitoring reignition surges that may occur after the operation of a circuit breaker in the power network. The number of reignition surges experienced by electrical equipment can be recorded by means of monitoring device 10, which is connected to the grounding cable of surge arrester 12. The surge counter may be configured as a reignition counter. Monitoring device 10 provides information related to the degree of transient overvoltage experienced by the facility, and it serves as a monitoring device for surge arrester 12. Monitoring device 10 may be sensitive to the charge content or amplitude of the pulse current passing through surge arrester 12, which is caused by an intrusion surge in the live wire to which surge arrester is connected. Re-ignition is a transient overvoltage that may occur due to certain circuit breaker operations. Re-ignition may occur when a circuit breaker is disconnected, depending on the site layout, the type of load present, the power factor, and the type of circuit breaker used. Re-ignition can also cause severe overvoltages, and in unfavorable locations, surge arresters are recommended to protect electrical equipment such as transformers. Then, it may also be necessary to monitor the actual occurrence of overvoltages due to reignition.

[0017] Power surges caused by reignition have several characteristics compared to surges caused by lightning. Typically, reignition surges occur more frequently, occurring several times in a very short period, and are of lower amplitude. Reignitions are characterized by typically starting with a small amplitude, and the amplitude usually increases with each subsequent reignition. This is due to the increasingly larger contact gap of the circuit breaker during its disconnection process. Another characteristic of reignitions is that they occur in large numbers within a short period, for example, 10 to 20 times within 1 millisecond (ms). Furthermore, if a surge arrester is present to ultimately limit the overvoltage caused by reignition, the final current surge can have a significantly longer duration compared to the previous surges.

[0018] Now refer to Figure 2 The flowchart shown illustrates some actions that may be performed by a monitoring device 10 for monitoring surge arrester 12 according to embodiments described herein. Surge arrester 12 is connected to a power grid to protect electrical equipment 14 of the power grid from intrusive surges through surge arrester 12. The power grid may include circuit breakers. These actions do not necessarily have to be performed in the order described below, but can be performed in any suitable order, and are more likely to be performed simultaneously. Optional actions that may be performed in some embodiments are marked with dashed boxes.

[0019] Action 201 According to the embodiments described herein, it is important to be able to count the number of reignition surges in order to analyze and collect information related to the power supply conditions experienced by electrical equipment 14. Based on this information, the power network operator can determine whether it is necessary to improve the protection of electrical equipment 14, for example, by increasing the number of surge arresters. Therefore, monitoring device 10 first detects reignition surges caused by the switching of a circuit breaker. Reignition surge counting may include obtaining one or more current pulses, for example, detecting one or more current pulses. In one embodiment, obtaining one or more current pulses may include obtaining a sample of the current signal passing through surge arrester 12 and processing the digitized sample to isolate one or more current pulses. The monitoring device may include a broadband current sensor for measuring the pulse current passing through surge arrester 12 and an analog-to-digital (A / D) converter for sampling and digitizing the measured current pulse signal. In another embodiment, obtaining one or more current pulses is performed with the aid of a digital counter circuit that increments the count when a pulse is detected electronically and can provide an analog or digital reading of a representative magnitude (e.g., peak value) of the pulse observed over a specific time period.

[0020] According to some implementations, one or more current pulses, such as reignition surges, can occur before surge arrester 12 is activated, i.e., before a low-impedance path is provided for the switching surge current. According to some implementations, the detected one or more current pulses can be counted based on the satisfaction of a threshold condition, for example, obtaining the detected one or more current pulses, which may be pre-configured.

[0021] Threshold conditions can be quantitative threshold conditions (signals exceeding a pre-configured noise level) used to detect the occurrence of pulses, or duration threshold conditions used to help separate reignition pulses (i.e., to detect when a reignition pulse ends so that one pulse can be distinguished from another). Threshold conditions can also be configured as percentage threshold conditions, especially for quantitative thresholds, which can be configured as a percentage of the maximum measurable value to detect pulses above the noise band in the signal, such as pulses above 5% of a 10V signal (maximum value).

[0022] According to one example, the duration threshold is met when the current pulse lasts for less than 50 microseconds.

[0023] Action 202 The monitoring device 10 then counts, for example, calculates, the number of detected reignition surges caused by the switching of the circuit breaker. The monitoring device may include a surge counter, such as a reignition counter, and the detection and counting in action 201 may be performed by the reignition counter, which in one embodiment is a digital counter.

[0024] Action 203 The monitoring device 10 generates monitoring data based on detected reignition surges. The monitoring device 10 may also include a processing unit, such as a processor or controller, and the monitoring data based on the detected reignition surges can be executed by the processing unit. The processing unit can be used to coordinate and control the operation of the monitoring device 10, and also to provide post-processing information (e.g., timestamped surge magnitude values, or simply a count of reignition surges). The processing unit may also support suitable interfaces and communication modules to transmit the processed information to a user or another device for monitoring or further processing. In another embodiment, the processing of digitized samples can be performed offline by other devices used to detect reignition surges and provide surge magnitude values ​​and counts.

[0025] According to some embodiments, it will be valuable to install the monitoring device 10 in any location where reignition may occur, for example, in a cable system where the vacuum circuit breaker frequently trips or malfunctions under inductive load conditions. The monitoring device 10 will be particularly valuable in locations where problems arise due to reignition. The monitoring device 10 can identify the cause of the problem or demonstrate that appropriate actions have been taken to resolve it, such as installing a surge arrester to limit voltage.

[0026] The implementation described herein relates to monitoring reignition surges; however, various types of surges (e.g., surges caused by re-breakdowns due to switches in power networks dominated by capacitive loads) can be monitored by making appropriate configuration settings related to pulse detection (e.g., changing threshold conditions).

[0027] According to some implementations, the monitoring device 10 can be capable of generating data in multiple forms, i.e., providing data. The data may include detailed information, wherein each reignition is provided with a timestamp and amplitude. The data may also include summary information, such as stating "within x ms", "y surges occurred", "they were likely caused by reignition", and "surge discharger limited / unlimited overvoltage". See the typical features above. Comparisons between the three phases can also provide important information regarding whether so-called virtual current chopping has occurred. Overvoltages occurring with virtual current chopping may be significantly greater than overvoltages occurring with multiple reignitions without virtual current chopping.

[0028] The surge arrester 12 has a highly nonlinear impedance. Under nominal operating conditions, i.e., when there is no surge, only a very small leakage current flows through the surge arrester, and when the surge arrester limits the voltage, it exhibits a very low impedance. When a reignition occurs, the surge arrester 12 is generally still represented primarily by a capacitor. However, due to the presence of capacitance in the surge arrester 12, a small current surge flows through it each time a reignition occurs. Therefore, it can be useful to have a current detection device (e.g., a Pearson broadband current transformer, or any broadband current sensor such as a Rogowski coil or a compensating resistor capable of measuring fast transients) in the monitoring device 10 to measure the current flowing through the surge arrester 12 caused by the reignition surge. Thus, the monitoring device 10 detects / measures the reignition (count, amplitude, timestamp). Detecting such fast transients that occur during a reignition is a challenge, for which a broadband current transformer is proposed as part of the solution. Another challenge lies in processing reignition pulses, such as current pulses, because these pulses repeat within the first 8th cycle of the power cycle (e.g., less than 2.5 ms for 50 Hz). The data acquisition electronics must digitize the signal quickly enough to record the waveform of the reignition pulse. Laboratory tests illustrating examples of the implementations described herein will be further described below, and... Figures 3a to 6b The representative curves are used to illustrate these laboratory tests. The laboratory tests were performed on a 900kVA three-phase 20kV cable system, in which a vacuum circuit breaker was disconnected during inductive loads and a surge arrester was installed to protect the transformer.

[0029] Figure 3aThis document describes examples of voltages observed in a cable system during a surge, derived from laboratory tests, with voltage values ​​plotted along a time axis. An overview of the circuit breaker tripping activity is thus illustrated, showing the first voltage relative to ground observed in the cable system. The normally applied voltage NO1 is seen before circuit breaker operation, and an overvoltage surge is observed in the cable system after the circuit breaker trips CBO1.

[0030] Another example of overvoltage surges is Figure 3b The figure illustrates the second-phase-to-ground voltage observed in a three-phase cable system during circuit breaker tripping. Under normal operating conditions NO 2, a regular line voltage is shown, while an overvoltage surge is observed after circuit breaker tripping CBO 2. A similar overvoltage surge (not shown) is also observed in the third phase of the cable system during circuit breaker operation.

[0031] Figure 4a and Figure 4b The diagram illustrates an example of surge current measured from laboratory testing during circuit breaker tripping, used for monitoring surge current through surge arresters connected in two phases of a three-phase cable system. Therefore, an overview of the circuit breaker tripping activity is illustrated, showing the current through surge arresters connected in the first and second phases of the three-phase cable system. Under normal operating conditions NO 3 ( Figure 4a ) and NO4 ( Figure 4b Under these conditions, a small leakage current flows through the surge arresters connected in each phase. When the circuit breaker trips CBO 3 ( Figure 4a ) and CBO 4 ( Figure 4b Afterward, the surge current is observed as a pulse current passing through a surge arrester in the corresponding line (phase of the cable system). Typical surge monitoring devices detect this pulse and count it as a switching surge. This is due to the characteristics of the current measurement in the monitoring device of a typical surge monitoring device that counts switching surges or lightning surges, and the monitoring device may not count more than 2 surges per second.

[0032] Surge activity observed at a time resolution of less than 1 millisecond (ms) indicates the presence of multiple surges caused by reignition. Figure 5a The text describes an example of voltage measured in the first phase of a cable system from laboratory testing, where voltage values ​​derived from a sequence of sampled digital signals are plotted along a time axis. A reignition occurs during the circuit breaker tripping CBO 5. Reignitions can occur with increasing amplitude over a period of approximately 1 ms. Each reignition surge (overvoltage) generates a capacitive current surge through the surge arrester. Finally, a longer-duration current pulse occurs when the surge arrester begins to limit voltage LV 1.

[0033] Figure 5b Another example of the voltage measured in the second phase of a cable system from laboratory testing is described, where the voltage values ​​also describe the reignition surge that occurred when the circuit breaker disconnected CBO 6, limiting the overvoltage LV2.

[0034] Figure 6a The image shows an example of a reignition surge current measured from laboratory testing through a surge arrester connected to the first phase of a three-phase cable system, where current values ​​derived from a sequence of digital signals sampled using a fast A / D converter are plotted along the time axis. The surge current through the surge arrester was measured using an external Pearson broadband current transformer. A reignition occurs over approximately 1 ms during the circuit breaker tripping CBO 7, accompanied by an increasingly larger surge. Each reignition surge generates a significant capacitive current surge through the surge arrester, and finally, a longer-duration current pulse occurs when the surge arrester begins to limit the voltage LV 3.

[0035] Figure 6b Another example of a reignition surge current measured from laboratory testing via a surge arrester connected to the second phase of a cable system is shown. The occurrence of the reignition surge during the circuit breaker's tripping CBO 8 is described, as well as the instant the surge arrester begins to limit voltage LV 4 (resulting in a longer-duration current pulse). However, using current measurements with features such as, for example, a Pearson broadband current transformer or the like, one can obtain... Figures 5a to 6b Similar results are shown, and reignition can be detected. Measuring devices with features such as Pearson broadband current transformers can be additional devices specifically designed for measuring reignition surges, as well as measuring devices made for switching surges and / or lightning surges.

[0036] According to examples of embodiments described herein, a monitoring device 10, which may include a reignition counter, may be connected to a broadband current sensor and may measure the current signal (sample and digitize the current signal) or use a digital counter to detect and count reignition pulses. The monitoring device 10 has the capability to detect pulse bursts within a 1ms time period using a current sensor (e.g., at a sampling rate of approximately 1 microsecond or faster) or to perform appropriate waveform shaping on the detected pulses, and to count the pulses using a digital counter.

[0037] In embodiments where pulses are sampled using a fast analog-to-digital converter, the sampled data can be processed, for example, by a processor to detect multiple reignition pulses, such as current pulses. Reignition pulses can be identified as bursts of pulses that occur after circuit breaker operation until surge arrester 12 is activated. Activity, pulse count, and magnitude can be identified from the sampled current waveform. In embodiments described herein, monitoring device 10 can also detect reignition surges occurring before the surge arrester is activated to verify whether surge arrester 12 is activated near the protection level (overvoltage) designed for its activation. This determination can be made by processing the sampled current signal passing through surge arrester 12.

[0038] According to another example of the embodiments described herein, the monitoring device 10 may also be capable of capturing switching surges / lightning surges, since the waveform from the broadband current signal will also respond to the current waveform of the switching surge / lightning surge, and identification of these switching surges / lightning surges can be accomplished by processing the captured waveform data.

[0039] In order to perform the above-described method for monitoring the surge arrester 12, the monitoring device 10 may include... Figure 7 The block diagram described in the document.

[0040] The monitoring device 10 may include processing circuitry 701, such as one or more processors, configured to perform the methods described herein.

[0041] Monitoring device 10 may include detection unit 702. Monitoring device 10, processing circuitry 701, and / or detection unit 702 are configured to detect reignition surges caused by the switching of the circuit breaker. Detecting a reignition surge may include acquiring, for example, detecting one or more current pulses. In one embodiment, acquiring one or more current pulses is performed with the aid of pulse wave shaping electronics. The one or more current pulses may occur before a surge arrester is activated. In some embodiments, acquiring one or more current pulses may include acquiring a sample and processing the sample to isolate the one or more current pulses. Monitoring device 10 may also include an A / D converter, and the sample is acquired by the A / D converter. Detecting one or more current pulses may be based on satisfying a threshold condition, which may be pre-configured.

[0042] The monitoring device 10 may include a calculation unit 703. The monitoring device 10, the processing circuit 701, and / or the calculation unit 703 may be configured to calculate, for example, count, the number of detected reignition surges caused by the switching of the circuit breaker.

[0043] The monitoring device 10 may include a generation unit 704. The monitoring device 10, the processing circuit 701, and / or the generation unit 704 may be configured to generate monitoring data based on detected reignition surges.

[0044] The monitoring device 10 also includes a memory 707. The memory 707 includes: one or more units for storing data such as current pulses, reignition surge information, measurements and observations made by the monitoring device and / or sensors, input / output data, metadata, etc.; and an application program for performing the methods disclosed herein when implemented; and the like. The monitoring device 10 may also include a communication interface.

[0045] The methods for monitoring device 10 according to the embodiments described herein are implemented by means of, for example, a computer program product 708 or a computer program, which includes instructions, i.e., software code portions, that, when implemented on at least one processor, cause at least one processor to perform the actions described herein as performed by monitoring device 10. Computer program product 708 may be stored on a computer-readable storage medium 709, such as an optical disc, a Universal Serial Bus (USB) disk, or the like. The computer-readable storage medium 709 storing the computer program product may include instructions that, when implemented on at least one processor, cause at least one processor to perform the actions described herein as performed by monitoring device 10. In some embodiments, the computer-readable storage medium may be a temporary or non-temporary computer-readable storage medium.

[0046] As will be readily understood by those skilled in communication design, such functional devices or circuits can be implemented using digital logic and / or one or more microcontrollers, microprocessors, or other digital hardware. In some implementations, multiple or all of the various functions can be implemented together, for example, in a single application-specific integrated circuit (ASIC), or in two or more separate devices, wherein there are suitable hardware and / or software interfaces between the two or more separate devices. For example, multiple functions can be implemented on a processor shared with other functional components of the UE or network node.

[0047] Alternatively, some functional elements of the processing unit under discussion may be provided using dedicated hardware, while other functional elements may be provided with hardware for implementing the software in association with suitable software or firmware. Therefore, the terms "processor" or "controller" as used herein do not exclusively refer to hardware capable of implementing software and may implicitly include, but are not limited to, digital signal processor (DSP) hardware and / or program or application data. Other conventional and / or custom hardware may also be included. Designers of communication devices will understand the inherent cost, performance, and maintenance trade-offs in these design choices.

[0048] It should be noted that, where appropriate, any feature of any aspect can be applied to any other aspect. Similarly, any advantage of any aspect can be applied to any other aspect.

[0049] Generally, all terms used in the claims should be interpreted according to their ordinary meaning in the technical field, unless otherwise expressly defined herein. All references to “a / an / the element, device, component, apparatus, step, etc.” should be explicitly interpreted as referring to at least one instance of the element, device, component, apparatus, step, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless expressly stated. The use of “first,” “second,” etc., for different features / components of this disclosure is intended only to distinguish these features / components from other similar features / components, and not to assign any order or hierarchy to these features / components.

[0050] It will be understood that the foregoing description and figures represent non-limiting examples of the methods and winding arrangements taught herein. Therefore, the winding arrangements and techniques taught herein are not limited to the foregoing description and figures. Rather, the embodiments described herein are limited only by the following claims and their legal equivalents.

Claims

1. A monitoring device (10) for monitoring power surges through a surge arrester (12), the surge arrester (12) being connected to a power grid to protect electrical equipment (14) of the power grid from intrusive power surges through the surge arrester (12), wherein, The monitoring device (10) is used for: Detect reignition surge, which is caused by the switching of a circuit breaker; The monitoring device (10) is used to detect the reignition surge by obtaining one or more current pulses, wherein the one or more current pulses occur before the activation of the surge discharger (12), and wherein obtaining the one or more current pulses includes detecting at least one current pulse lasting less than 50 microseconds.

2. The monitoring device (10) according to claim 1, wherein, The monitoring device (10) is also used for: The number of detected reignition surges, which were caused by the switching of the circuit breaker, is calculated.

3. The monitoring device (10) according to claim 1, wherein, Obtaining one or more current pulses includes obtaining digitized samples and processing the samples to isolate the one or more current pulses.

4. The monitoring device (10) according to claim 1, wherein, The one or more current pulses are obtained based on a threshold condition that is met for detecting the one or more current pulses.

5. The monitoring device (10) according to claim 4, wherein, The threshold conditions are duration threshold conditions and / or magnitude threshold conditions.

6. The monitoring device (10) according to claim 4, wherein, The threshold condition is a percentage threshold condition, which is a percentage of the maximum measurable value.

7. The monitoring device (10) according to any one of claims 1 to 6, wherein, The monitoring device (10) is also used to generate monitoring data based on the detected reignition surge.

8. A method performed by a monitoring device (10) for monitoring a surge through a surge arrester (12), the surge arrester (12) being connected to a power grid to protect electrical equipment (14) of the power grid from intrusive surges through the surge arrester (12), the method comprising: Detect (201) a reignition surge, which is caused by the switching of a circuit breaker; Detecting the reignition surge includes obtaining one or more current pulses; The one or more current pulses occur before the surge discharger (12) is activated; Obtaining the one or more current pulses includes detecting at least one current pulse lasting less than 50 microseconds.

9. The method according to claim 8, further comprising: Calculate (202) the number of reignition surges detected, which are caused by the switching of the circuit breaker.

10. The method according to claim 8, wherein, Obtaining one or more current pulses includes obtaining a digitized sample and processing the sample to separate the one or more current pulses.

11. The method according to any one of claims 8 to 10, further comprising: (203) Monitoring data is generated based on the detected reignition surge.

Images