Method, device and equipment for monitoring inter-turn short circuit of generator outlet voltage transformer

Abstract

The application relates to a generator outlet voltage transformer inter-turn short circuit monitoring method, device and equipment. The method comprises the following steps: acquiring a delta winding voltage signal of a secondary side opening of a generator outlet voltage transformer and a zero sequence voltage signal of a generator neutral point, determining a fault area of the generator according to the delta winding voltage signal and the zero sequence voltage signal, acquiring a temperature signal, a primary side current signal and a partial discharge signal of the voltage transformer in the case that the fault area is the voltage transformer body, and determining an inter-turn short circuit level of the voltage transformer according to the temperature signal, the primary side current signal and the partial discharge signal; in the method, the PT inter-turn short circuit state is monitored based on multidimensional signals, the PT inter-turn short circuit misjudgment and omission caused by only relying on a single voltage signal are reduced, and the monitoring accuracy is improved.

Description

Technical Field

[0001] This application relates to the field of power fault monitoring technology, and in particular to methods, devices and equipment for monitoring inter-turn short circuits in generator outlet voltage transformers. Background Technology

[0002] The generator output voltage transformer (PT), as a core device at the generator terminal, provides critical voltage signal support for terminal voltage measurement, energy metering, relay protection logic, and excitation closed-loop regulation. Therefore, PT failure will seriously threaten the safe operation of the generator unit.

[0003] Inter-turn short circuits in power PTs are a frequent type of fault in generators. Related technologies typically employ infrared thermography or partial discharge detection on the power PT cabinet to monitor the inter-turn short circuit status.

[0004] However, the relevant technologies have poor accuracy in monitoring inter-turn short circuits in PTs. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, device, and equipment for monitoring inter-turn short circuits in generator outlet voltage transformers to address the aforementioned technical problems.

[0006] In a first aspect, this application provides a method for monitoring inter-turn short circuits in a generator outlet voltage transformer, including:

[0007] Obtain the voltage signal of the open delta winding on the secondary side of the generator outlet voltage transformer and the zero-sequence voltage signal of the generator neutral point;

[0008] The fault area of ​​the generator is determined based on the delta winding voltage signal and the zero-sequence voltage signal;

[0009] When the fault area is the voltage transformer body, acquire the voltage transformer's temperature signal, primary current signal, and partial discharge signal.

[0010] The inter-turn short-circuit level of the voltage transformer is determined based on the temperature signal, primary current signal, and partial discharge signal.

[0011] In one embodiment, determining the fault region of the generator based on the delta winding voltage signal and the zero-sequence voltage signal includes:

[0012] Correlation analysis was performed on the delta winding voltage signal and the zero-sequence voltage signal to obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal;

[0013] The fault area of ​​the generator is determined based on the abnormal changes.

[0014] In one embodiment, determining the fault region of the generator based on abnormal change relationships includes:

[0015] When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously, the fault area of ​​the generator is determined to be the voltage transformer body.

[0016] When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change abnormally simultaneously, the fault area of ​​the generator is determined to be outside the voltage transformer body.

[0017] In one embodiment, determining the inter-turn short-circuit level of the voltage transformer based on temperature signals, primary-side current signals, and partial discharge signals includes:

[0018] The temperature signal is compared longitudinally with the preset temperature reference value, and the temperature signals of different phases are compared laterally to determine the temperature anomaly assessment result;

[0019] The primary current signal is compared longitudinally with the preset current reference value, and the primary current signals of different phases are compared laterally to determine the assessment result of primary current anomaly.

[0020] The partial discharge signal is compared longitudinally with a preset background noise benchmark value, and the partial discharge signals of different phases are compared laterally to determine the partial discharge anomaly assessment result.

[0021] The inter-turn short circuit level is determined based on the results of temperature anomaly assessment, primary side current anomaly assessment, and partial discharge anomaly assessment.

[0022] In one embodiment, the inter-turn short-circuit level is determined based on the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, including:

[0023] If no abnormalities are found in the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be mild.

[0024] If there is an anomaly in the temperature anomaly assessment result, the primary side current anomaly assessment result, and the partial discharge anomaly assessment result, the inter-turn short circuit level is determined to be general.

[0025] If two of the abnormalities are found in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be moderate.

[0026] If three anomalies are found in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be severe.

[0027] In one embodiment, the method further includes:

[0028] Obtain the target alarm form corresponding to the inter-turn short circuit level, and issue an alarm according to the target alarm form; the target alarm form includes at least one of the following: audible and visual alarm, communication upload, screen display, and external relay closure.

[0029] Secondly, this application also provides a generator outlet voltage transformer inter-turn short-circuit monitoring device, comprising:

[0030] The first acquisition module is used to acquire the voltage signal of the delta winding of the generator outlet voltage transformer with the secondary side open and the zero-sequence voltage signal of the generator neutral point.

[0031] The fault determination module is used to determine the fault area of ​​the voltage transformer based on the delta winding voltage signal and the zero-sequence voltage signal.

[0032] The second acquisition module is used to acquire the temperature signal, primary current signal and partial discharge signal of the voltage transformer when the fault area is the voltage transformer body.

[0033] The rating determination module is used to determine the inter-turn short circuit rating of the voltage transformer based on temperature signals, primary side current signals, and partial discharge signals.

[0034] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-mentioned generator outlet voltage transformer inter-turn short circuit monitoring.

[0035] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-mentioned generator outlet voltage transformer inter-turn short circuit monitoring.

[0036] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in the above-mentioned generator outlet voltage transformer inter-turn short circuit monitoring.

[0037] In the aforementioned method, apparatus, and equipment for monitoring inter-turn short circuits of generator outlet voltage transformers, the fault area of ​​the generator is determined by acquiring the voltage signal of the open delta winding on the secondary side of the generator outlet voltage transformer and the zero-sequence voltage signal of the generator neutral point. When the fault area is the voltage transformer body, the temperature signal, primary current signal, and partial discharge signal of the voltage transformer are acquired, and the inter-turn short circuit level of the voltage transformer is determined based on these signals. This method monitors the inter-turn short circuit status of the PT based on multi-dimensional signals including delta winding voltage signal, zero-sequence voltage signal, temperature signal, primary current signal, and partial discharge signal. The use of delta winding voltage signal and zero-sequence voltage signal to distinguish the fault area, and the collaborative determination of the inter-turn short circuit level based on temperature signal, primary current signal, and partial discharge signal, reduces the false positives and false negatives caused by relying solely on a single voltage signal, thereby improving monitoring accuracy. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an internal structural diagram of a computer device in one embodiment;

[0040] Figure 2 This is a flowchart illustrating a PT inter-turn short-circuit monitoring method in one embodiment;

[0041] Figure 3 This is a schematic diagram of the generator set in one embodiment;

[0042] Figure 4 This is a schematic diagram showing the positional relationship between the PT cabinet and the PT body in one embodiment;

[0043] Figure 5 This is a flowchart illustrating the process of determining a fault area in one embodiment;

[0044] Figure 6 This is a flowchart illustrating the process of determining the fault area in another embodiment;

[0045] Figure 7 This is a flowchart illustrating the process of determining the inter-turn short-circuit level in one embodiment;

[0046] Figure 8This is a flowchart illustrating the process of determining the inter-turn short-circuit level in another embodiment;

[0047] Figure 9 This is a flowchart illustrating the PT inter-turn short-circuit monitoring method in another embodiment;

[0048] Figure 10 This is a schematic diagram of the architecture of a monitoring system in one embodiment;

[0049] Figure 11 This is a structural block diagram of a PT inter-turn short-circuit monitoring device in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0052] The method for monitoring inter-turn short circuits in generator outlet voltage transformers provided in this application embodiment can be applied to, for example... Figure 1 The computer device shown can be a terminal, and its internal structure diagram can be as follows. Figure 1As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for monitoring inter-turn short circuits in a generator outlet voltage transformer. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0053] Those skilled in the art will understand that Figure 1 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0054] In one exemplary embodiment, such as Figure 2 As shown, a method for monitoring inter-turn short circuits in a generator outlet voltage transformer is provided, which can be applied to... Figure 1 Taking the computer equipment (hereinafter referred to as monitoring equipment) as an example, the following steps are included:

[0055] S210. Obtain the voltage signal of the delta winding of the generator outlet voltage transformer secondary side opening and the zero-sequence voltage signal of the generator neutral point.

[0056] The generator outlet is equipped with a PT cabinet, which contains the PT unit. Under normal generator operation, the voltage signal of the delta winding is close to 0.

[0057] Optionally, for the PT at the outlet of any generator set, such as Figure 3As shown, the monitoring equipment can acquire the voltage signal at the output terminal of the open delta winding on the secondary side of the PT, denoted as delta winding voltage signal 3U0, and acquire the voltage signal on the secondary side of the neutral point grounding transformer or single-phase voltage transformer in the generator neutral point grounding cabinet, denoted as zero-sequence voltage signal U. n .

[0058] It should be noted that the sampling frequencies of the delta winding voltage signal and the zero-sequence voltage signal are kept consistent to ensure that the timing data is fully aligned and to achieve synchronous acquisition of the two signals.

[0059] S220. Determine the fault area of ​​the generator based on the delta winding voltage signal and the zero-sequence voltage signal.

[0060] Among them, the fault area of ​​the generator may be the PT body or a non-PT body, such as generator stator grounding or external system single-phase grounding fault.

[0061] Optionally, the monitoring equipment can determine the fault area of ​​the generator set based on changes in the delta winding voltage signal and the zero-sequence voltage signal.

[0062] For example, the delta winding voltage signal 3U0 and the zero-sequence voltage signal U are acquired in real time. n Taking a preset voltage threshold U as an example, for a certain moment, when 3U0 > U and U n If the value is greater than U, the fault area of ​​the generator is determined to be the PT body; otherwise, the fault area of ​​the generator is determined to be outside the PT body. The monitoring equipment can also analyze 3U0 and U over a period of time. n The fault identification model is input together with the pre-trained fault identification model to obtain the fault area of ​​the generator set output by the fault identification model, such as the PT body or the non-PT body.

[0063] S230. When the fault area is the voltage transformer body, acquire the temperature signal, primary current signal and partial discharge signal of the voltage transformer.

[0064] The temperature signal of the PT body can be obtained by a temperature probe installed inside the PT cabinet. The current signal is the current signal of the neutral point lead on the primary side of the PT, which can be obtained by a high-precision power frequency current transformer mounted on the neutral point lead of the primary winding. This current transformer has an open-close structure and can be installed without disconnecting the primary winding lead. The partial discharge signal is the signal collected by detecting partial discharge in the PT, which can be obtained by a high-frequency current transformer (HFCT) mounted on the neutral point grounding wire of the primary winding. This current transformer also has an open-close structure and can be installed without disconnecting the primary winding lead.

[0065] For example, the temperature probe can be an infrared temperature probe. When multiple temperature signals can be detected at different locations, the temperature signal corresponding to the highest temperature is acquired and used as the temperature signal of the PT body.

[0066] To fully cover the surface of the PT body and obtain a more comprehensive temperature reading, multiple temperature probes can be installed. For example... Figure 4 As shown, an infrared temperature probe, denoted as T1 and T2, is installed on each of the left and right sides inside the generator outlet PT cabinet. The overlapping fields of view of the two probes cover the entire area of ​​the PT body. The highest temperature value of the PT body area measured by T1 and T2 is taken as the temperature signal of the PT body.

[0067] Optionally, for the PT at the outlet of any generator set, such as Figure 3 As shown, the monitoring equipment acquires the temperature of the PT body by setting a temperature detector in the PT cabinet, which is recorded as temperature signal T. It also acquires the current on the neutral point side lead of the primary winding of the PT, which is recorded as primary side current signal I. In addition, it acquires the high-frequency partial discharge current of the PT primary side neutral point grounding circuit, which is recorded as partial discharge signal Q.

[0068] It should be noted that, similar to the delta winding voltage signal and the zero-sequence voltage signal, the sampling frequencies of the PT body's temperature signal, primary side current signal, and partial discharge signal are kept consistent to ensure that the timing data is fully aligned and to achieve synchronous acquisition of the three signals.

[0069] S140. Determine the inter-turn short-circuit level of the voltage transformer based on the temperature signal, primary current signal, and partial discharge signal.

[0070] Among them, the inter-turn short-circuit rating of the voltage transformer is used to quantify the severity of an inter-turn short circuit in the PT.

[0071] Optionally, after obtaining the temperature signal, primary current signal, and partial discharge signal of the PT body, the monitoring equipment can jointly determine the inter-turn short circuit level of the voltage transformer based on the temperature signal, primary current signal, and partial discharge signal.

[0072] For example, the monitoring device can also input the T, I, and Q values ​​over a period of time into a pre-trained level identification model to obtain the inter-turn short circuit level output by the level identification model, such as high, medium, or low level.

[0073] In this embodiment, the fault area of ​​the generator is determined by acquiring the delta winding voltage signal of the secondary side opening of the generator outlet voltage transformer and the zero-sequence voltage signal of the generator neutral point. When the fault area is the voltage transformer body, the temperature signal, primary current signal, and partial discharge signal of the voltage transformer are acquired, and the inter-turn short-circuit level of the voltage transformer is determined based on these signals. This method monitors the inter-turn short-circuit state of the PT based on multi-dimensional signals including delta winding voltage signal, zero-sequence voltage signal, temperature signal, primary current signal, and partial discharge signal. The delta winding voltage signal and zero-sequence voltage signal are used to distinguish the fault area, and the temperature signal, primary current signal, and partial discharge signal are used in conjunction to determine the inter-turn short-circuit level. This reduces the false positives and false negatives of inter-turn short circuits caused by relying solely on a single voltage signal, thereby improving monitoring accuracy.

[0074] To determine the fault area of ​​the generator, in one embodiment, such as Figure 5 As shown, S220 above, determining the generator fault area based on the delta winding voltage signal and the zero-sequence voltage signal, includes:

[0075] S510. Perform correlation analysis on the delta winding voltage signal and the zero-sequence voltage signal to obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal.

[0076] The abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal is used to characterize whether the abnormal changes occur synchronously between the delta winding voltage signal and the zero-sequence voltage signal. For example, the abnormal change relationship can be synchronous or asynchronous.

[0077] Optionally, the monitoring equipment can perform correlation analysis on the synchronously acquired delta winding voltage signal and zero-sequence voltage signal to analyze the changing trends of the two signals and obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal, whether the abnormal change occurs synchronously or asynchronously.

[0078] For example, correlation analysis can be achieved by calculating the correlation coefficient of the changing trends of two signals or comparing the amplitude change ratios of the two signals. The larger the absolute value of the correlation coefficient of the changing trends of the two signals, or the more stable the amplitude change ratios of the two signals, the stronger the correlation and the higher the degree of synchronization between the two signals.

[0079] S520. Determine the fault area of ​​the generator based on the abnormal change relationship.

[0080] Optionally, after obtaining the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal, the monitoring equipment can determine the fault area corresponding to the obtained abnormal change relationship based on the preset correspondence between the abnormal change relationship and the fault area, and use it as the fault area of ​​the generator.

[0081] In an alternative embodiment, such as Figure 6 As shown, S520 above, determining the generator fault area based on abnormal change relationships, includes:

[0082] S610. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously, the fault area of ​​the generator is determined to be the voltage transformer body.

[0083] In this case, the asynchronous abnormal changes in the delta winding voltage signal and the zero-sequence voltage signal usually indicate an abnormality in the zero-sequence voltage signal, while the delta winding voltage signal remains normal. This is due to the asymmetry of the three-phase magnetic circuit caused by an inter-turn short circuit within the PT itself, while the generator neutral point voltage remains unaffected. Therefore, when the asynchronous abnormal changes in the delta winding voltage signal and the zero-sequence voltage signal occur, the fault area of ​​the generator can be determined to be the PT itself; otherwise, it is not the PT itself.

[0084] S620. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change abnormally at the same time, the fault area of ​​the generator is determined to be the non-voltage transformer body.

[0085] The synchronous abnormal changes in the delta winding voltage signal and the zero-sequence voltage signal are caused by other faults in the generator, such as generator stator grounding or single-phase grounding faults in the external system.

[0086] Optionally, the monitoring equipment can determine that the fault area of ​​the generator is the PT body when the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously; conversely, when the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change synchronously, the fault area of ​​the generator is determined to be not the PT body, but rather the generator side or an external system.

[0087] In this embodiment, correlation analysis is performed on the delta winding voltage signal and the zero-sequence voltage signal to obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal. The fault area of ​​the generator is determined based on the abnormal change relationship. Specifically, when the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously, the fault area of ​​the generator is determined to be the voltage transformer body. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change synchronously, the fault area of ​​the generator is determined to be not the voltage transformer body. In the above method, the zero-sequence voltage signal of the generator neutral point is introduced as a reference system and correlated with the open delta winding voltage signal of the PT secondary side. The abnormal change of the two signals not occurring synchronously (i.e., 3U0 changes + Un remains unchanged) is used to lock the fault of the PT's own inter-turn short circuit, which improves the reliability of generator fault area identification.

[0088] To obtain the inter-turn short-circuit rating of PT, in one embodiment, such as Figure 7 As shown, S240 above, determining the inter-turn short-circuit level of the voltage transformer based on temperature signals and partial discharge signals, includes:

[0089] S710. The temperature signal is compared longitudinally with the preset temperature reference value, and the temperature signals of different phases are compared laterally to determine the temperature anomaly assessment result.

[0090] Here, the temperature signals of different phases refer to the temperature signals of different phase PTs. The generator outlet has three phases: A, B, and C, each equipped with a separate PT for phase A, phase B, and phase C.

[0091] For any generator outlet PT, it is necessary not only to compare the temperature signal of the PT with the preset temperature reference value longitudinally, but also to compare the temperature signal of the PT with the temperature signals of the other two phase PTs laterally.

[0092] Optionally, for any generator outlet PT, the monitoring device performs a longitudinal comparison of the PT's temperature signal with a preset temperature reference value to obtain a longitudinal comparison result. If the temperature signal is greater than the preset temperature reference value, the longitudinal comparison result is determined to be abnormal; otherwise, it is normal. Simultaneously, the monitoring device can acquire the temperature information of the other two phase PTs and perform a lateral comparison of the three-phase temperature signals together with the PT's temperature signal to obtain a lateral comparison result. For example, it compares the temperature difference between the PT's temperature signal and the other two phase temperature signals. If a temperature difference exceeds a preset temperature difference threshold, the lateral comparison result is determined to be abnormal; otherwise, it is normal.

[0093] After obtaining the longitudinal and lateral temperature comparison results, the monitoring equipment comprehensively determines the temperature anomaly assessment result based on the longitudinal and lateral temperature comparison results.

[0094] For example, the monitoring device can determine the temperature anomaly assessment result as abnormal if at least one of the horizontal and vertical temperature comparison results is abnormal; conversely, it can determine the temperature anomaly assessment result as normal if both the horizontal and vertical temperature comparison results are normal.

[0095] S720. The primary current signal is compared longitudinally with the preset cable library benchmark value, and the primary current signals of different phases are compared laterally to determine the primary current anomaly assessment result.

[0096] It should be noted that when the generator is running normally, the primary current of the PT is only the excitation current in the milliampere range; when an inter-turn short circuit occurs, the circulating current within the short-circuit turn causes the primary current of that phase to increase significantly.

[0097] Similar to temperature signals of different phases, primary current signals of different phases refer to the primary current signals of different phase PTs.

[0098] For any generator outlet PT, it is necessary not only to compare the primary current signal of the PT with the preset current reference value longitudinally, but also to compare the primary current signal of the PT with the primary current signals of the other two phase PTs laterally.

[0099] Optionally, for any generator outlet PT, the monitoring device performs a longitudinal comparison of the primary side current signal of the PT with a preset current reference value to obtain the longitudinal comparison result of the primary side current. If the primary side current is greater than the preset current reference value, the longitudinal comparison result is determined to be abnormal; otherwise, it is normal. Simultaneously, the monitoring device can acquire the primary side current signals of the other two phase PTs and perform a transverse comparison of the three-phase primary side current signals together with the primary side current signal of the PT to obtain the transverse comparison result of the primary side current. For example, the device compares the current difference between the primary side current signal of the PT and the primary side current signals of the other two phases. If there is a current difference greater than a preset current difference threshold, the transverse comparison result is determined to be abnormal; otherwise, it is normal.

[0100] After obtaining the longitudinal and transverse comparison results of the primary current, the monitoring equipment comprehensively determines the assessment result of the primary current anomaly based on the longitudinal and transverse comparison results of the primary current.

[0101] For example, the monitoring device may determine that the primary current abnormality assessment result is abnormal if at least one of the horizontal comparison result and the vertical comparison result of the primary current is abnormal; conversely, if both the horizontal comparison result and the vertical comparison result of the primary current are normal, the primary current abnormality assessment result is determined to be normal.

[0102] S730. The partial discharge signal is compared longitudinally with the preset background noise reference value, and the partial discharge signals of different phases are compared laterally to determine the partial discharge anomaly assessment result.

[0103] Similar to temperature signals of different phases, partial discharge signals of different phases refer to the partial discharge signals of different phase PTs.

[0104] For any generator outlet PT, it is necessary not only to compare the partial discharge signal of the PT longitudinally with the preset background noise reference value, but also to compare the partial discharge signal of the PT laterally with the partial discharge signals of the other two phase PTs.

[0105] Optionally, for any generator outlet PT, the monitoring device performs a longitudinal comparison of the PT's partial discharge signal with a preset background noise reference value to obtain the longitudinal comparison result of the partial discharge signal. If the partial discharge signal is greater than the preset background noise reference value, the longitudinal comparison result is determined to be abnormal; otherwise, it is normal. Simultaneously, the monitoring device can acquire the partial discharge signals of the other two phase PTs and perform a lateral comparison of the three-phase partial discharge signals together with the partial discharge signal of the current PT to obtain the lateral comparison result of the partial discharge signal. For example, the signal difference between the partial discharge signal of the current PT and the partial discharge signals of the other two phases is compared. If there is a signal difference greater than a preset signal difference threshold, the lateral comparison result is determined to be abnormal; otherwise, it is normal.

[0106] After obtaining the longitudinal and lateral comparison results of the partial discharge signals, the monitoring equipment comprehensively determines the partial discharge anomaly assessment result based on the longitudinal and lateral comparison results of the partial discharge signals.

[0107] For example, the monitoring device may determine that the primary current abnormality assessment result is abnormal if at least one of the horizontal comparison result and the vertical comparison result of the primary current is abnormal; conversely, if both the horizontal comparison result and the vertical comparison result of the primary current are normal, the primary current abnormality assessment result is determined to be normal.

[0108] S740. Determine the inter-turn short circuit level based on the results of temperature anomaly assessment, primary side current anomaly assessment, and partial discharge anomaly assessment.

[0109] Optionally, after obtaining the above-mentioned temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the monitoring equipment can comprehensively determine the inter-turn short circuit level of the generator outlet PT based on the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, or it can determine the inter-turn short circuit level based on at least one of the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results.

[0110] For example, when the inter-turn short-circuit level is determined comprehensively based on the results of temperature anomaly assessment, primary side current anomaly assessment, and partial discharge anomaly assessment, the monitoring equipment can determine the inter-turn short-circuit level according to the degree of attention given to each anomaly assessment result. Taking the degree of attention for temperature anomaly assessment, primary side current anomaly assessment, and partial discharge anomaly assessment as decreasing in that order, and inter-turn short-circuit levels as high, medium, and low, the method for determining the inter-turn short-circuit level is as follows:

[0111] If the temperature anomaly assessment result is abnormal among the three anomaly assessment results mentioned above, the inter-turn short circuit level is determined to be high; if the temperature anomaly assessment result is normal among the three anomaly assessment results mentioned above, and the primary side current anomaly assessment result is abnormal, the inter-turn short circuit level is determined to be medium; if the temperature anomaly assessment result and the primary side current anomaly assessment result are normal among the three anomaly assessment results mentioned above, and the partial discharge anomaly assessment result is abnormal, the inter-turn short circuit level is determined to be low.

[0112] In this embodiment, the temperature signal is compared longitudinally with a preset temperature reference value, and the temperature signals of different phases are compared laterally to determine the temperature anomaly assessment result. The primary current signal is compared longitudinally with a preset current reference value, and the primary current signals of different phases are compared laterally to determine the primary current anomaly assessment result. The partial discharge signal is compared longitudinally with a preset background noise reference value, and the partial discharge signals of different phases are compared laterally to determine the partial discharge anomaly assessment result. Then, the inter-turn short circuit level is determined based on the temperature anomaly assessment result, the primary current anomaly assessment result, and the partial discharge anomaly assessment result. In the above method, based on the three-dimensional signals of temperature, primary current, and partial discharge, each signal is simultaneously subjected to longitudinal reference comparison and lateral three-dimensional comparison to achieve multi-dimensional cross-verification and fusion to determine the inter-turn short circuit level of the PT, which greatly improves the reliability and accuracy of the level diagnosis.

[0113] Taking the inter-turn short circuit levels of a PT, including mild, moderate, and severe, as an example, in one embodiment, such as... Figure 8 As shown, the above-mentioned S740 determines the inter-turn short circuit level based on the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, including:

[0114] S810. If the results of the temperature anomaly assessment, the primary side current anomaly assessment, and the partial discharge anomaly assessment are all normal, the inter-turn short circuit level is determined to be mild.

[0115] S820. If there is an anomaly in the temperature anomaly assessment result, the primary side current anomaly assessment result, and the partial discharge anomaly assessment result, the inter-turn short circuit level is determined to be general.

[0116] S830. If two of the following are abnormalities in the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be moderate.

[0117] S840. If three abnormalities are found in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be severe.

[0118] Among them, mild, moderate, medium and severe correspond to the increasing severity of inter-turn short circuits in the PT.

[0119] Optionally, after obtaining the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the monitoring equipment can perform statistical analysis on the above three anomaly assessment results. If there are no anomalies in the above three anomaly assessment results, the inter-turn short circuit level of the generator outlet PT is determined to be slight; if there is one anomaly in the above three anomaly assessment results, the inter-turn short circuit level of the generator outlet PT is determined to be moderate; if there are two anomalies in the above three anomaly assessment results, the inter-turn short circuit level of the generator outlet PT is determined to be moderate; and if there are three anomalies in the above three anomaly assessment results, the inter-turn short circuit level of the generator outlet PT is determined to be severe.

[0120] In this embodiment, if there are no abnormalities in the temperature anomaly assessment results, primary current anomaly assessment results, and partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be mild; if there is one abnormality in any of these three assessment results, the inter-turn short circuit level is determined to be moderate; if there are two abnormalities in any of these three assessment results, the inter-turn short circuit level is determined to be moderate; and if there are three abnormalities in any of these three assessment results, the inter-turn short circuit level is determined to be severe. This method classifies the inter-turn short circuit level into four categories—mild, moderate, moderate, and severe—based on the number of abnormal results in the three assessment results, achieving a refined classification of the inter-turn short circuit level. Furthermore, the classification process is simple and easy to implement, thereby improving the accuracy of the obtained inter-turn short circuit level.

[0121] After obtaining the inter-turn short-circuit level of PT, in one embodiment, the above method further includes:

[0122] Obtain the target alarm form corresponding to the inter-turn short circuit level, and issue an alarm according to the target alarm form; the target alarm form includes at least one of the following: audible and visual alarm, relay closure, communication upload, and screen display.

[0123] Among these, audible and visual alarms refer to the monitoring equipment emitting alarm signals through sound, light, or a combination thereof, such as flashing indicator lights on the monitoring equipment's panel and / or sounding an internal buzzer. Relay closure refers to the monitoring equipment controlling the closure of a relay connected to an external device to transmit the PT's fault information. Communication upload refers to the monitoring equipment sending alarm messages through a communication interface. Screen display refers to the monitoring equipment displaying fault information through its own display terminal.

[0124] Optionally, after obtaining the inter-turn short circuit level of PT, the monitoring equipment can determine the alarm form corresponding to the obtained inter-turn short circuit level based on the preset correspondence between inter-turn short circuit level and alarm form, record it as the target alarm form, and use the target alarm form to issue an alarm.

[0125] In this embodiment, the target alarm form corresponding to the inter-turn short circuit level is obtained, and alarms are issued according to the target alarm form. The target alarm form includes at least one of audible and visual alarm, communication uploading, screen display, and external relay closure. In the above method, by adopting the target alarm form adapted to the inter-turn fault level, the alarm effect for different inter-turn fault levels can be improved accordingly. Moreover, the alarm form supports multiple alarm methods such as audible and visual prompts, remote reporting, interface display, and relay linkage output, taking into account both on-site reminders and remote push from the background. The alarm output channels are rich and can be adapted to different operation and maintenance management modes, ensuring that fault information is delivered to operation and maintenance personnel in a timely and reliable manner.

[0126] To facilitate understanding by those skilled in the art, the monitoring method for inter-turn short circuits in generator outlet voltage transformers provided in this application is described in detail below, such as... Figure 9 As shown, the method may include:

[0127] S901. Obtain the voltage signal of the delta winding of the generator outlet voltage transformer secondary side opening and the zero-sequence voltage signal of the generator neutral point.

[0128] S902. Perform correlation analysis on the delta winding voltage signal and the zero-sequence voltage signal to obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal;

[0129] S903. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously, the fault area of ​​the generator is determined to be the voltage transformer body.

[0130] S904. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change abnormally at the same time, the fault area of ​​the generator is determined to be not the voltage transformer body.

[0131] S905. When the fault area is the voltage transformer body, acquire the temperature signal, primary current signal and partial discharge signal of the voltage transformer.

[0132] S906. Compare the temperature signal with the preset temperature reference value longitudinally, and compare the temperature signals of different phases laterally to determine the temperature anomaly assessment result.

[0133] S907. Compare the primary current signal with the preset current reference value longitudinally, and compare the primary current signals of different phases laterally to determine the primary current anomaly assessment result.

[0134] S908. The partial discharge signal is compared longitudinally with the preset background noise reference value, and the partial discharge signals of different phases are compared laterally to determine the partial discharge anomaly assessment result.

[0135] S909. If there are no abnormalities in the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be mild.

[0136] S910. If there is an anomaly in the temperature anomaly assessment result, the primary side current anomaly assessment result, and the partial discharge anomaly assessment result, the inter-turn short circuit level shall be determined as general.

[0137] S911. If two of the following are abnormalities in the temperature anomaly assessment results, primary side current anomaly assessment results, and partial discharge anomaly assessment results, the inter-turn short circuit level shall be determined to be moderate.

[0138] S912. If three abnormalities exist in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be severe.

[0139] S913. Obtain the target alarm form corresponding to the inter-turn short circuit level, and issue an alarm according to the target alarm form; the target alarm form includes at least one of the following: audible and visual alarm, communication upload, screen display, and external relay closure.

[0140] In an optional embodiment, the above-described method for monitoring inter-turn short circuits in the generator outlet voltage transformer is applied to... Figure 10 The monitoring system shown.

[0141] The monitoring system comprises a field equipment layer, a signal acquisition and processing layer, and an execution layer. The field equipment layer generates five signals: the delta winding voltage signal, the zero-sequence voltage signal, the temperature signal, the primary side current signal, and the partial discharge signal. These signals are collected and aggregated by the various acquisition modules in the integrated detection device within the signal acquisition and processing layer. The integrated logic decision unit then processes the data to determine the inter-turn short circuit level, and the execution layer issues an alarm using the target alarm format corresponding to the inter-turn short circuit level.

[0142] It should be noted that the descriptions in S901-S913 above can be found in the relevant descriptions in the above embodiments, and their effects are similar, so they will not be repeated here.

[0143] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0144] Based on the same inventive concept, this application also provides a generator outlet voltage transformer inter-turn short-circuit monitoring device for implementing the generator outlet voltage transformer inter-turn short-circuit monitoring method described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the generator outlet voltage transformer inter-turn short-circuit monitoring device provided below can be found in the limitations of the generator outlet voltage transformer inter-turn short-circuit monitoring method described above, and will not be repeated here.

[0145] In one exemplary embodiment, such as Figure 11 As shown, a generator outlet voltage transformer inter-turn short circuit monitoring device is provided, comprising: a first acquisition module 1101, a fault determination module 1102, a second acquisition module 1103, and a fault level determination module 1104, wherein:

[0146] The first acquisition module 1101 is used to acquire the voltage signal of the delta winding of the generator outlet voltage transformer secondary side opening and the zero-sequence voltage signal of the generator neutral point.

[0147] The fault determination module 1102 is used to determine the fault area of ​​the voltage transformer based on the delta winding voltage signal and the zero-sequence voltage signal;

[0148] The second acquisition module 1103 is used to acquire the temperature signal, primary current signal and partial discharge signal of the voltage transformer when the fault area is the voltage transformer body.

[0149] The rating determination module 1104 is used to determine the inter-turn short circuit rating of the voltage transformer based on the temperature signal, the primary side current signal, and the partial discharge signal.

[0150] Each module in the aforementioned generator outlet voltage transformer inter-turn short-circuit monitoring device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0151] In one exemplary embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps in any of the above-described generator outlet voltage transformer inter-turn short circuit monitoring.

[0152] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, performs the steps in any of the above-described generator outlet voltage transformer inter-turn short-circuit monitoring.

[0153] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the steps in any of the above-described generator outlet voltage transformer inter-turn short circuit monitoring.

[0154] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0155] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0156] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for monitoring inter-turn short circuits in a generator outlet voltage transformer, characterized in that, The method includes: Obtain the voltage signal of the delta winding with the secondary side open of the generator outlet voltage transformer and the zero-sequence voltage signal of the generator neutral point; The fault area of ​​the generator is determined based on the delta winding voltage signal and the zero-sequence voltage signal; When the fault area is the voltage transformer body, the temperature signal, primary current signal and partial discharge signal of the voltage transformer are acquired. The inter-turn short-circuit level of the voltage transformer is determined based on the temperature signal, the primary current signal, and the partial discharge signal.

2. The method according to claim 1, characterized in that, Determining the fault region of the generator based on the delta winding voltage signal and the zero-sequence voltage signal includes: Correlation analysis is performed on the delta winding voltage signal and the zero-sequence voltage signal to obtain the abnormal change relationship between the delta winding voltage signal and the zero-sequence voltage signal; The fault area of ​​the generator is determined based on the abnormal change relationship.

3. The method according to claim 2, characterized in that, Determining the fault region of the generator based on the abnormal change relationship includes: When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal do not change synchronously, the fault area of ​​the generator is determined to be the voltage transformer body. When the abnormal change relationship is that the delta winding voltage signal and the zero-sequence voltage signal change abnormally synchronously, it is determined that the fault area of ​​the generator is not the voltage transformer body.

4. The method according to any one of claims 1-3, characterized in that, Determining the inter-turn short-circuit level of the voltage transformer based on the temperature signal, the primary current signal, and the partial discharge signal includes: The temperature signal is compared longitudinally with a preset temperature reference value, and the temperature signals of different phases are compared laterally to determine the temperature anomaly assessment result. The primary current signal is compared longitudinally with a preset current reference value, and the primary current signals of different phases are compared laterally to determine the assessment result of primary current anomaly. The partial discharge signal is compared longitudinally with a preset background noise reference value, and the partial discharge signals of different phases are compared laterally to determine the partial discharge anomaly assessment result. The inter-turn short circuit level is determined based on the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results.

5. The method according to claim 4, characterized in that, The step of determining the inter-turn short circuit level based on the temperature anomaly assessment result, the primary side current anomaly assessment result, and the partial discharge anomaly assessment result includes: If no abnormality is found in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be mild. If any one of the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results is an anomaly, the inter-turn short circuit level is determined to be general. If two of the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results are found to be abnormal, the inter-turn short circuit level is determined to be moderate. If three anomalies are found in the temperature anomaly assessment results, the primary side current anomaly assessment results, and the partial discharge anomaly assessment results, the inter-turn short circuit level is determined to be severe.

6. The method according to any one of claims 1-3, characterized in that, The method further includes: Obtain the target alarm form corresponding to the inter-turn short circuit level, and issue an alarm according to the target alarm form; the target alarm form includes at least one of audible and visual alarm, communication upload, screen display, and external relay closure.

7. A generator outlet voltage transformer inter-turn short-circuit monitoring device, characterized in that, The device includes: The first acquisition module is used to acquire the voltage signal of the delta winding of the generator outlet voltage transformer secondary side opening and the zero-sequence voltage signal of the generator neutral point; The fault determination module is used to determine the fault area of ​​the voltage transformer based on the delta winding voltage signal and the zero-sequence voltage signal. The second acquisition module is used to acquire the temperature signal, primary current signal and partial discharge signal of the voltage transformer when the fault area is the voltage transformer body. The rating determination module is used to determine the inter-turn short circuit rating of the voltage transformer based on the temperature signal, the primary side current signal, and the partial discharge signal.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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