Early warning method and device for generator outlet voltage transformer
By using microampere-level current measurement and phase analysis, the problem of difficulty in monitoring early inter-turn faults in the generator outlet voltage transformer winding was solved, enabling high-precision online monitoring and early warning of slow fuse melting and inter-turn short circuit faults, thus ensuring the stable operation of the power generation system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUODIAN NANJING ELECTRIC POWER TEST RES CO LTD
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-01
AI Technical Summary
In the existing technology, early inter-turn faults in the generator outlet voltage transformer winding are difficult to detect effectively, and the protection of the monitoring and protection device is not perfect enough, which makes it impossible to achieve accurate monitoring and early warning of faults, resulting in unit outages and equipment damage.
By employing a microampere-level current measuring device, the resistive current is extracted by measuring the primary winding current of the voltage transformer and performing phase analysis. A reasonable threshold is then set to enable online monitoring and early warning of slow fuse melting and inter-turn short circuit faults.
It improves the accuracy and early warning capability of voltage transformer fault monitoring, reduces unit outages and equipment damage caused by faults, and enhances the stability and safety of the power generation system.
Smart Images
Figure CN121955853A_ABST
Abstract
Description
Early warning method and device for generator outlet voltage transformer Technical Field
[0001] This application relates to the field of generator early warning technology, and in particular to an early warning method and device for a generator outlet voltage transformer. Background Technology
[0002] The generator output PT (voltage transformer) plays a crucial role in the generator system. Its working principle is based on the law of electromagnetic induction, using electromagnetic coupling to convert the high-amplitude voltage at the generator output into a low-voltage signal used by various generator protection devices, metering devices, and generator excitation regulation according to a precise transformation ratio. This conversion process provides standardized electrical input for power system monitoring and control, ensuring that various secondary devices can obtain real-time generator operating voltage information. Furthermore, the voltage signal output by the generator output PT provides key criteria for determining the power system's operating status and identifying anomalies for protection systems such as generator stator grounding protection and inter-turn short-circuit protection. Therefore, the safety and reliability of the generator output PT is a vital link in ensuring the stable operation of the power generation system.
[0003] To prevent generator outages and equipment damage caused by generator outlet PT (power supply transformer) failures, the industry has established corresponding standards for the operation, maintenance, and repair of generator outlet PTs. For example, these standards stipulate that insulation tests such as withstand voltage and partial discharge of the generator outlet PT should be conducted during major generator overhauls. Despite these strict standards and regulations, the operation of generator outlet PTs still faces safety hazards, and generator outages caused by generator outlet PT failures occur frequently.
[0004] In related technologies, early inter-turn faults in windings are not easily detected effectively. Monitoring and protection devices for voltage transformers are not yet perfect enough to directly monitor and protect against faults, let alone identify early inter-turn insulation faults in voltage transformer windings. For faults such as slow melting and inter-turn short circuits, the mainstream monitoring method in the industry is to measure the secondary voltage and set a threshold for secondary voltage change analysis. This method has low accuracy, makes it difficult to achieve early fault warning, and can easily cause unnecessary property losses, which urgently needs to be improved. Summary of the Invention
[0005] This application provides an early warning method and device for a generator outlet voltage transformer to solve the problems in related technologies, such as the difficulty in effectively detecting early inter-turn faults in the windings, the inadequacy of monitoring and protection devices for voltage transformers, the inability to directly monitor and protect against faults, and the inability to determine early inter-turn insulation faults in the voltage transformer windings.
[0006] The first aspect of this application provides a method for early warning of a generator outlet voltage transformer, comprising the following steps: acquiring at least one current characteristic of the generator outlet voltage transformer and matching the amplitude range of the at least one current characteristic to control the generator outlet voltage transformer to switch current levels according to the amplitude range, thereby acquiring current level switching data of the generator outlet voltage transformer; calculating the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer; based on the phase difference angle, obtaining a resistive component from the primary winding current, and in response to the resistive component being greater than a preset threshold, identifying the fault type of the generator outlet voltage transformer based on the resistive component and the current level switching data, thereby triggering an early warning action of the corresponding level of the generator outlet voltage transformer according to the fault type.
[0007] Optionally, in one embodiment of this application, calculating the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer includes: determining the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer; and calculating the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and the spectral resolution.
[0008] Optionally, in one embodiment of this application, the formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
[0009] Optionally, in one embodiment of this application, the step of controlling the generator outlet voltage transformer to switch current ranges according to the amplitude range to collect current range switching data of the generator outlet voltage transformer includes: detecting whether the at least one current characteristic is within a preset amplitude range; if the at least one current characteristic is within the preset amplitude range, controlling the first relay of the generator outlet voltage transformer to engage and the second relay to release, so as to switch the current range to a microampere-level measurement range and generate first switching data; if the at least one current characteristic is not within the preset amplitude range, controlling the second relay to engage and the first relay to release, so as to switch the current range to a milliampere-level measurement range and generate second switching data; and generating the current range switching data based on the first switching data and the second switching data.
[0010] Optionally, in one embodiment of this application, the step of identifying the fault type of the generator outlet voltage transformer based on the resistive component and the current range switching data, and triggering a corresponding level of early warning action for the generator outlet voltage transformer based on the fault type, includes: detecting whether the resistive component is greater than a first preset resistive threshold and less than a second preset resistive threshold; if the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold, then determining that the fault type of the generator outlet voltage transformer is a slow fuse melting fault type, and triggering a first-level early warning action for the generator outlet voltage transformer based on the slow fuse melting fault type; if the resistive component is greater than the second preset resistive threshold, then determining that the fault type of the generator outlet voltage transformer is an inter-turn short circuit fault type, and triggering a second-level early warning action for the generator outlet voltage transformer based on the inter-turn short circuit fault type, wherein the first preset resistive threshold is less than the second preset resistive threshold.
[0011] A second aspect of this application provides an early warning device for a generator outlet voltage transformer, comprising: a data acquisition module, configured to acquire at least one current characteristic of the generator outlet voltage transformer and match the amplitude range of the at least one current characteristic to control the generator outlet voltage transformer to switch current levels according to the amplitude range, thereby acquiring current level switching data of the generator outlet voltage transformer; a calculation module, configured to calculate the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer; and an early warning module, configured to obtain a resistive component based on the phase difference angle and the primary winding current, and, in response to the resistive component being greater than a preset threshold, identify the fault type of the generator outlet voltage transformer based on the resistive component and the current level switching data, thereby triggering an early warning action of the corresponding level of the generator outlet voltage transformer according to the fault type.
[0012] Optionally, in one embodiment of this application, the calculation module includes: a determining unit, configured to determine the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer; and a calculation unit, configured to calculate the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and the spectral resolution.
[0013] Optionally, in one embodiment of this application, the formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
[0014] Optionally, in one embodiment of this application, the acquisition module includes: a first detection unit, configured to detect whether the at least one current characteristic is within a preset amplitude range; a first control unit, configured to, in response to the at least one current characteristic being within the preset amplitude range, control the first relay of the generator outlet voltage transformer to engage and the second relay to release, so as to switch the current range to a microampere-level measurement range and generate first switching data; a second control unit, configured to, in response to the at least one current characteristic not being within the preset amplitude range, control the second relay to engage and the first relay to release, so as to switch the current range to a milliampere-level measurement range and generate second switching data; and a generation unit, configured to, based on the first switching data and the second switching data, generate the current range switching data.
[0015] Optionally, in one embodiment of this application, the early warning module includes: a second detection unit, configured to detect whether the resistive component is greater than a first preset resistive threshold and less than a second preset resistive threshold; a first early warning unit, configured to, in response to the resistive component being greater than the first preset resistive threshold and less than the second preset resistive threshold, determine that the fault type of the generator outlet voltage transformer is a slow-blow fuse fault, and trigger a first-level early warning action of the generator outlet voltage transformer according to the slow-blow fuse fault type; and a second early warning unit, configured to, in response to the resistive component being greater than the second preset resistive threshold, determine that the fault type of the generator outlet voltage transformer is an inter-turn short-circuit fault, and trigger a second-level early warning action of the generator outlet voltage transformer according to the inter-turn short-circuit fault type, wherein the first preset resistive threshold is less than the second preset resistive threshold.
[0016] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the early warning method for a generator outlet voltage transformer as described in the above embodiments.
[0017] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described early warning method for a generator outlet voltage transformer.
[0018] This application embodiment uses a microampere-level current measuring device to measure the primary winding current of a voltage transformer, performs phase analysis to extract the resistive current for real-time monitoring, and sets reasonable thresholds to comprehensively improve the online monitoring accuracy of faults such as slow-blow fuses and inter-turn short circuits in voltage transformers. This solves the problems in related technologies, such as the difficulty in effectively detecting early inter-turn faults in the winding, the inadequacy of monitoring and protection devices for voltage transformers, the inability to directly monitor and protect against faults, and the inability to diagnose early inter-turn insulation faults in voltage transformer windings.
[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 is a flowchart of an early warning method for a generator outlet voltage transformer according to an embodiment of this application; Figure 2 is a schematic diagram of current detection module switching according to an embodiment of this application; Figure 3 is a schematic diagram of simulated acquisition of fault current characteristics according to an embodiment of this application; Figure 4 is a schematic diagram of a system framework according to an embodiment of this application; Figure 5 is a schematic diagram of the structure of an early warning device for a generator outlet voltage transformer according to an embodiment of this application; Figure 6 is a schematic diagram of the structure of an electronic device according to an embodiment of this application. Detailed Implementation
[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.
[0022] The following describes a method and apparatus for early warning of a generator outlet voltage transformer according to an embodiment of this application, with reference to the accompanying drawings. Addressing the issues mentioned in the background art, such as the difficulty in effectively detecting early inter-turn faults in the windings, the inadequate protection provided by monitoring and protection devices for voltage transformers, the inability to directly monitor and protect against faults, and the inability to diagnose early inter-turn insulation faults in the voltage transformer windings, this application provides an early warning method for a generator outlet voltage transformer. In this method, a microampere-level current measuring device can be used to measure the primary winding current of the voltage transformer. Phase analysis is used to extract the resistive current for real-time monitoring. A reasonable threshold is set, comprehensively improving the online monitoring accuracy for faults such as slow-blow fuses and inter-turn short circuits in the voltage transformer. This solves the problems in the related art, such as the difficulty in effectively detecting early inter-turn faults in the windings, the inadequate protection provided by monitoring and protection devices for voltage transformers, the inability to directly monitor and protect against faults, and the inability to diagnose early inter-turn insulation faults in the voltage transformer windings.
[0023] Specifically, Figure 1 is a flowchart illustrating an early warning method for a generator outlet voltage transformer provided in an embodiment of this application.
[0024] As shown in Figure 1, the early warning method for the generator outlet voltage transformer includes the following steps: In step S101, at least one current characteristic of the generator outlet voltage transformer is collected, and the amplitude range of at least one current characteristic is matched, so as to control the generator outlet voltage transformer to switch current levels according to the amplitude range, so as to collect the current level switching data of the generator outlet voltage transformer.
[0025] It is understood that the amplitude range in the embodiments of this application can be a current range defined after quantitative analysis through hardware-in-the-loop simulation.
[0026] In actual implementation, the embodiments of this application can extract the current characteristics of the generator outlet voltage transformer under different fault conditions through hardware-in-the-loop simulation, and match the amplitude range of the current characteristics to control the generator outlet voltage transformer to switch current levels according to the amplitude range, so as to collect the current level switching data of the generator outlet voltage transformer and provide basic data support for subsequent fault identification.
[0027] This application proposes a high-precision generator outlet voltage transformer current monitoring device. By using a high-precision switchable current transformer with real-time communication function, the amplitude and phase of the primary winding of the voltage transformer are synchronously transmitted back to the monitoring device, ensuring accurate detection of the shunt amplitude and phase.
[0028] Optionally, in one embodiment of this application, controlling the generator outlet voltage transformer to switch current ranges according to the amplitude range to collect current range switching data of the generator outlet voltage transformer includes: detecting whether at least one current characteristic is within a preset amplitude range; if at least one current characteristic is within the preset amplitude range, controlling the first relay of the generator outlet voltage transformer to engage and the second relay to release, so as to switch the current range to a microampere-level measurement range and generate first switching data; if at least one current characteristic is not within the preset amplitude range, controlling the second relay to engage and the first relay to release, so as to switch the current range to a milliampere-level measurement range and generate second switching data; and generating current range switching data based on the first switching data and the second switching data.
[0029] It is understood that, as shown in Figure 2, the first relay in this embodiment can be K1 and the second relay can be K2.
[0030] In actual implementation, the current monitoring module in the monitoring system of this application uses a high-precision open-close current transformer. The current obtained by the current transformer is converted into voltage through a resistor. Because there are two measurement ranges, this application designs two sets of relays. The first relay K1 and the second relay can be K2. The power-on point K1 is energized by default, and K2 is released by default. Because the CT cannot be open-circuited during the test, this application, during the range switching process, if at least one current characteristic is within the preset amplitude range, such as switching from 100mA to 2mA, first controls... The first relay of the generator outlet voltage transformer is activated, and the second relay is released to switch the current range to the microampere level measurement range, generating the first switching data. If at least one current characteristic is not within the preset amplitude range, such as switching from 2mA to 100mA instead of from 100mA to 2mA, the second relay K2 is activated and the first relay K1 is released to switch the current range to the milliampere level measurement range, generating the second switching data. Based on the first and second switching data, current range switching data is generated, as shown in Figure 3.
[0031] In step S102, the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer is calculated.
[0032] It is understood that the phase difference angle in the embodiments of this application can be the phase offset angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer.
[0033] As shown in Figure 4, in the embodiment of this application, the secondary winding voltage and primary winding current of the generator outlet voltage transformer can be collected in the system application, thereby providing support for the subsequent extraction of the primary current phase difference.
[0034] Optionally, in one embodiment of this application, calculating the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer includes: determining the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer; and calculating the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and spectral resolution.
[0035] In actual implementation, the embodiments of this application can set the sampling frequency and spectral resolution according to the fundamental wave 50Hz to ensure sampling accuracy. Taking the secondary side voltage U2 as the phase reference, and setting its phase angle to 0°, the phase difference angle θ2 of the primary winding current I1 (fundamental effective value) relative to U2 is measured to determine the voltage transformer connection method. The angle difference is determined according to the actual measured value on site, and the accurate phase difference angle θ1 of the primary winding current I1 relative to the primary winding U1 can be obtained.
[0036] In step S103, based on the phase difference angle, the resistive component is obtained from the primary winding current. In response to the resistive component being greater than a preset threshold, the fault type of the generator outlet voltage transformer is identified based on the resistive component and the current level switching data, so as to trigger the corresponding level of early warning action of the generator outlet voltage transformer according to the fault type.
[0037] It is understood that the resistive component in the embodiments of this application can be the current component in the primary winding current of the generator outlet voltage transformer used to overcome winding insulation loss and contact resistance loss.
[0038] In actual implementation, the embodiments of this application can decompose the primary winding current I1 into resistive and inductive components based on θ1. In response to the resistive component being greater than a preset threshold, the fault type of the generator outlet voltage transformer can be identified based on the resistive component and the current range switching data. That is, this application can combine the monitoring module that switches the current range based on the characteristics of different types of fault currents with the phase analysis method that separates the resistive current of the generator outlet voltage transformer to effectively realize the monitoring and early warning of multiple fault types of the generator outlet voltage transformer, so as to trigger the corresponding level of early warning action of the generator outlet voltage transformer according to the fault type.
[0039] In one embodiment of this application, the primary winding current I1 can be decomposed into resistive and inductive components based on θ1. The formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
[0040] This application uses a microampere-level current measuring device to measure the primary winding current of the voltage transformer, analyzes the phase to extract the resistive current for real-time monitoring, sets reasonable thresholds, and comprehensively improves the online monitoring capability for faults such as slow fuse melting and inter-turn short circuits in the generator outlet voltage transformer.
[0041] Optionally, in one embodiment of this application, the fault type of the generator outlet voltage transformer is identified based on the resistive component and current range switching data, so as to trigger a corresponding level of early warning action for the generator outlet voltage transformer according to the fault type. This includes: detecting whether the resistive component is greater than a first preset resistive threshold and less than a second preset resistive threshold; if the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold, then the fault type of the generator outlet voltage transformer is determined to be a slow fuse melting fault type, and a first-level early warning action of the generator outlet voltage transformer is triggered according to the slow fuse melting fault type; if the resistive component is greater than the second preset resistive threshold, then the fault type of the generator outlet voltage transformer is determined to be an inter-turn short circuit fault type, and a second-level early warning action of the generator outlet voltage transformer is triggered according to the inter-turn short circuit fault type, wherein the first preset resistive threshold is less than the second preset resistive threshold.
[0042] It is understood that the first preset resistive threshold in the embodiments of this application can be the maximum value of the resistive component when the generator outlet voltage transformer is operating normally. Exceeding this value is determined to indicate that the insulation has begun to deteriorate. The second preset resistive threshold can be the upper limit of the resistive component that can be tolerated for a slow fuse melting fault. Exceeding this value is determined to indicate that the insulation is severely damaged or the winding is short-circuited.
[0043] In actual implementation, this application embodiment can detect whether the resistive component is greater than a first preset resistive threshold and less than a second preset resistive threshold. If the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold, the fault type of the generator outlet voltage transformer is determined to be a slow fuse melting fault. Based on the slow fuse melting fault type, a first-level early warning action of the generator outlet voltage transformer is triggered, such as sending a text alarm message to promptly remind maintenance personnel to handle the situation and prevent the fault from worsening. If the resistive component is greater than the second preset resistive threshold, the fault type of the generator outlet voltage transformer is determined to be an inter-turn short circuit fault. Based on the inter-turn short circuit fault type, a second-level early warning action of the generator outlet voltage transformer is triggered, such as sending an audible and visual alarm to the maintenance system and simultaneously pushing it to the maintenance personnel's mobile APP for rapid response and to prevent the fault from escalating. This application proposes an automatic switching method for voltage transformer current monitoring. Through semi-physical simulation, it collects and quantitatively analyzes fault currents such as "slow fuse melting" and "inter-turn short circuit" of the generator outlet voltage transformer, and automatically switches the current level for tracking different faults to achieve fault differentiation and degradation tracking.
[0044] This application further improves the fault early warning capability of the voltage transformer by simulating the primary winding current fault of the generator outlet voltage transformer, setting reasonable thresholds, and increasing measurement efficiency. It uses a microampere-level current measuring device to measure the primary winding current of the voltage transformer, and performs phase analysis to extract the resistive current for real-time monitoring. By setting reasonable thresholds, it comprehensively enhances the online monitoring capability for faults such as slow fuse melting and inter-turn short circuits in the generator outlet voltage transformer. According to the early warning method for the generator outlet voltage transformer proposed in this application, a microampere-level current measuring device can be used to measure the primary winding current of the voltage transformer, and phase analysis can be used to extract the resistive current for real-time monitoring. By setting reasonable thresholds, it comprehensively improves the online monitoring accuracy for faults such as slow fuse melting and inter-turn short circuits in the voltage transformer. This solves the problems of low accuracy in related technologies, the susceptibility of small changes in secondary voltage to various interferences, the difficulty in accurately predicting faults in the primary winding of the generator outlet voltage transformer, and the potential for unnecessary property damage.
[0045] Next, referring to the accompanying drawings, we describe the early warning device for the generator outlet voltage transformer according to an embodiment of this application.
[0046] Figure 5 is a schematic diagram of the early warning device of the generator outlet voltage transformer according to an embodiment of this application.
[0047] As shown in Figure 5, the early warning device 10 of the generator outlet voltage transformer includes: a data acquisition module 100, a calculation module 200, and an early warning module 300.
[0048] Specifically, the acquisition module 100 is used to acquire at least one current characteristic of the generator outlet voltage transformer and match the amplitude range of the at least one current characteristic, so as to control the generator outlet voltage transformer to switch current levels according to the amplitude range, and to acquire the current level switching data of the generator outlet voltage transformer.
[0049] The calculation module 200 is used to calculate the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer.
[0050] The early warning module 300 is used to obtain the resistive component based on the phase difference angle and the primary winding current, and in response to the resistive component being greater than a preset threshold, to identify the fault type of the generator outlet voltage transformer based on the resistive component and the current level switching data, so as to trigger the corresponding level of early warning action of the generator outlet voltage transformer according to the fault type.
[0051] Optionally, in one embodiment of this application, the calculation module 200 includes a determination unit and a calculation unit.
[0052] The determining unit is used to determine the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer.
[0053] The calculation unit is used to calculate the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and spectral resolution.
[0054] Optionally, in one embodiment of this application, the formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
[0055] Optionally, in one embodiment of this application, the acquisition module 100 includes: a first detection unit, a first control unit, a second control unit, and a generation unit.
[0056] The first detection unit is used to detect whether at least one current characteristic is within a preset amplitude range.
[0057] The first control unit is configured to control the first relay of the generator outlet voltage transformer to engage and the second relay to disengage in response to at least one current characteristic being within a preset amplitude range, so as to switch the current range to a microampere-level measurement range and generate first switching data.
[0058] The second control unit is used to control the second relay to engage and the first relay to release in response to at least one current characteristic not being within a preset amplitude range, so as to switch the current range to a milliampere-level measurement range and generate second switching data.
[0059] The generation unit is used to generate current level switching data based on the first switching data and the second switching data.
[0060] Optionally, in one embodiment of this application, the early warning module 300 includes: a second detection unit, a first early warning unit, and a second early warning unit.
[0061] The second detection unit is used to detect whether the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold.
[0062] The first early warning unit is used to determine the fault type of the generator outlet voltage transformer as a slow fuse melting fault type when the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold, and to trigger the first-level early warning action of the generator outlet voltage transformer according to the slow fuse melting fault type.
[0063] The second early warning unit is used to determine that the fault type of the generator outlet voltage transformer is an inter-turn short circuit fault type when the resistive component is greater than the second preset resistive threshold, and to trigger the secondary early warning action of the generator outlet voltage transformer according to the inter-turn short circuit fault type, wherein the first preset resistive threshold is less than the second preset resistive threshold.
[0064] It should be noted that the explanation of the aforementioned early warning method embodiment for the generator outlet voltage transformer also applies to the early warning device for the generator outlet voltage transformer in this embodiment, and will not be repeated here.
[0065] The early warning device for the generator outlet voltage transformer proposed in this application can use a microampere-level current measuring device to measure the primary winding current of the voltage transformer, analyze the phase to extract the resistive current for real-time monitoring, and set a reasonable threshold to comprehensively improve the online monitoring accuracy of faults such as slow melting of the voltage transformer's matching fuse and inter-turn short circuits. This solves the problem in related technologies where early inter-turn faults in the winding are not easily detected, the monitoring and protection devices for voltage transformers are not sufficiently robust, and they cannot directly monitor and protect against faults, let alone determine early inter-turn insulation faults in the voltage transformer windings.
[0066] Figure 6 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: a memory 601, a processor 602, and a computer program stored in the memory 601 and executable on the processor 602.
[0067] When the processor 602 executes the program, it implements the early warning method for the generator outlet voltage transformer provided in the above embodiments.
[0068] Furthermore, the electronic device also includes a communication interface 603 for communication between the memory 601 and the processor 602.
[0069] The memory 601 is used to store computer programs that can run on the processor 602.
[0070] The memory 601 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.
[0071] If the memory 601, processor 602, and communication interface 603 are implemented independently, they can be interconnected via a bus to communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, only one thick line is used in Figure 6, but this does not indicate that there is only one bus or one type of bus.
[0072] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.
[0073] The processor 602 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.
[0074] This embodiment also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described early warning method for the generator outlet voltage transformer.
[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0077] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.
[0078] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.
[0079] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.
[0080] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.
[0081] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.
[0082] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.
Claims
1. A method for early warning of a generator output voltage transformer, characterized in that, Includes the following steps: At least one current characteristic of the generator outlet voltage transformer is collected, and the amplitude range of the at least one current characteristic is matched to control the generator outlet voltage transformer to switch current levels according to the amplitude range, thereby collecting the current level switching data of the generator outlet voltage transformer; the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer is calculated; based on the phase difference angle, the resistive component is obtained from the primary winding current, and in response to the resistive component being greater than a preset threshold, the fault type of the generator outlet voltage transformer is identified according to the resistive component and the current level switching data, thereby triggering a warning action of the corresponding level of the generator outlet voltage transformer according to the fault type.
2. The method according to claim 1, characterized in that, The calculation of the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer includes: determining the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer; and calculating the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and the spectral resolution.
3. The method according to claim 1, characterized in that, The formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
4. The method according to claim 1, characterized in that, The step of controlling the generator outlet voltage transformer to switch current ranges according to the amplitude range, and collecting current range switching data of the generator outlet voltage transformer, includes: detecting whether at least one current characteristic is within a preset amplitude range; if at least one current characteristic is within the preset amplitude range, controlling the first relay of the generator outlet voltage transformer to engage and the second relay to release, so as to switch the current range to a microampere-level measurement range and generate first switching data; if at least one current characteristic is not within the preset amplitude range, controlling the second relay to engage and the first relay to release, so as to switch the current range to a milliampere-level measurement range and generate second switching data; and generating the current range switching data based on the first switching data and the second switching data.
5. The method according to claim 1, characterized in that, The step of identifying the fault type of the generator outlet voltage transformer based on the resistive component and the current range switching data, and triggering a corresponding level of early warning action for the generator outlet voltage transformer based on the fault type, includes: detecting whether the resistive component is greater than a first preset resistive threshold and less than a second preset resistive threshold; if the resistive component is greater than the first preset resistive threshold and less than the second preset resistive threshold, then determining that the fault type of the generator outlet voltage transformer is a slow fuse melting fault type, and triggering a first-level early warning action for the generator outlet voltage transformer based on the slow fuse melting fault type; if the resistive component is greater than the second preset resistive threshold, then determining that the fault type of the generator outlet voltage transformer is an inter-turn short circuit fault type, and triggering a second-level early warning action for the generator outlet voltage transformer based on the inter-turn short circuit fault type, wherein the first preset resistive threshold is less than the second preset resistive threshold.
6. A warning device for a generator outlet voltage transformer, characterized in that, include: The acquisition module is used to acquire at least one current characteristic of the generator outlet voltage transformer and match the amplitude range of the at least one current characteristic, so as to control the generator outlet voltage transformer to switch current levels according to the amplitude range, and to acquire the current level switching data of the generator outlet voltage transformer. The calculation module is used to calculate the phase difference angle between the primary winding current and the secondary winding voltage of the generator outlet voltage transformer; The early warning module is used to obtain the resistive component based on the phase difference angle and the primary winding current, and in response to the resistive component being greater than a preset threshold, to identify the fault type of the generator outlet voltage transformer based on the resistive component and the current level switching data, so as to trigger the corresponding level of early warning action of the generator outlet voltage transformer according to the fault type.
7. The apparatus according to claim 6, characterized in that, The calculation module includes: a determination unit, used to determine the sampling frequency and spectral resolution of the generator outlet voltage transformer based on the fundamental frequency of the generator outlet voltage transformer; and a calculation unit, used to calculate the phase difference angle between the primary winding current and the secondary winding voltage based on the sampling frequency and the spectral resolution.
8. The apparatus according to claim 7, characterized in that, The formula for calculating the resistive component is: I R =I1cosθ1 where I1 is the primary winding current and θ1 is the phase difference angle.
9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the early warning method for a generator outlet voltage transformer as described in any one of claims 1-5.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the early warning method for the generator outlet voltage transformer as described in any one of claims 1-5.