Stator core fault standard local excitation temperature rise measurement method and system

Abstract

The invention relates to a stator core fault standard local excitation temperature rise measurement method and system, computer equipment, a storage medium and a computer program product. The method is applied to a temperature rise measurement system, and comprises the following steps: after a standard local excitation frequency is applied to a fault tooth part, calculating first flux density power according to the reading of a first power analyzer and the reading of a second power analyzer; calculating standard flux density power based on the first flux density power, the standard local excitation frequency and the target local excitation frequency; after the target local excitation frequency is applied to the fault tooth part, second flux density power is calculated according to the reading of the first power analyzer and the reading of the second power analyzer; and when the second flux density power is equal to the standard flux density power, carrying out temperature rise measurement for preset time to obtain the standard local excitation temperature rise of the fault tooth part. By adopting the method, the standard local excitation temperature rise of the stator core fault can be measured under the condition that the standard excitation frequency is changed.

Description

Technical Field

[0001] This application relates to the field of fault detection and diagnosis technology for electric motors, and in particular to a method, system, computer equipment, computer-readable storage medium, and computer program product for measuring the standard local excitation temperature rise of stator core faults. Background Technology

[0002] The stator core is an important component of a large generator. When the insulation between the stator core laminations is damaged, it can cause significant losses. Therefore, insulation diagnosis of the stator core is an important task in generator maintenance.

[0003] Traditional stator core fault diagnosis methods commonly used include the iron loss method and the electromagnetic fault detection method (ELCID). While the iron loss method can directly reflect the temperature rise of the faulty tooth, it requires an MVA-level power supply, which is difficult to implement in power plants and can easily damage the generator. ELCID, on the other hand, only requires a KVA-level power supply and can be implemented in power plants. However, because ELCID provides results in quadrature-axis current, it cannot directly display the temperature rise, thus requiring supplementary iron loss testing. In practice, however, the quadrature-axis current often exceeds the standard while the iron loss test passes, easily leading to misdiagnosis of the faulty tooth.

[0004] Currently, a local excitation method has been proposed to determine the faulty teeth of the stator core. However, the standard for judging stator core faults needs to be based on the standard excitation temperature rise measured under the standard excitation frequency and standard excitation magnetic flux density. The local excitation method requires changing the standard excitation frequency when measuring the temperature rise of the faulty teeth of the stator core, which makes it impossible to directly use the stator core fault judgment standard to determine whether the stator core has failed.

[0005] Therefore, how to measure the standard local excitation temperature rise of stator core faults under the condition of changing the standard excitation frequency is an urgent problem to be solved. Summary of the Invention

[0006] Therefore, it is necessary to provide a method, system, computer equipment, computer-readable storage medium, and computer program product for measuring the standard local excitation temperature rise of stator core faults, which can measure the standard local excitation temperature rise of stator core faults under the condition of changing the standard excitation frequency, in order to address the above-mentioned technical problems.

[0007] Firstly, this application provides a method for measuring the standard local excitation temperature rise in stator core faults.

[0008] This is applied to a temperature rise measurement system, which includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer. The local excitation core is placed on the teeth on both sides of a faulty tooth on the stator core, the faulty tooth being on a first lamination of the stator core. The circulating current elimination core is placed on a second lamination. The first power analyzer is placed in the circuit formed by the local excitation core and the first lamination. The second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination. The method includes:

[0009] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0010] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0011] In one embodiment, after applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer, including:

[0012] After applying a standard local excitation frequency to the faulty tooth, the readings of the first power analyzer and the second power analyzer are received; the reading of the first power analyzer is taken as the total power loss of the faulty circuit of the stator core; the reading of the second power analyzer is taken as the total power loss of the normal circuit of the stator core.

[0013] The first magnetic flux density power is obtained by calculating the difference between the total power loss in the fault circuit of the stator core and the total power loss in the normal circuit of the stator core.

[0014] In one embodiment, the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency, including:

[0015] Obtain the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying a standard local excitation frequency to the faulty tooth;

[0016] Based on preset simulation data, it was confirmed that when the target local excitation frequency was applied to the faulty tooth, the magnetic flux density of the second stator core yoke was the same as that of the local excitation core.

[0017] Based on the first magnetic flux density power, the magnetic flux density of the first stator core yoke, and the magnetic flux density of the second stator core yoke, calculate the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke is the same as that of the second stator core yoke after applying a standard local excitation frequency to the faulty tooth; use the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0018] In one embodiment, the method further includes:

[0019] Based on the standard local excitation temperature rise, determine whether the faulty tooth has malfunctioned;

[0020] If a faulty tooth is confirmed to be faulty, determine the degree of heat generated in the faulty tooth.

[0021] In one embodiment, the total power loss of the stator core fault circuit includes: local excitation core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke loss power, stator core normal yoke loss power, silicon steel sheet loss power, keyway loss power, and stator core fault tooth loss power; the total power loss of the stator core normal circuit includes: circulating current elimination core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke loss power, and stator core normal yoke loss power; the first magnetic flux density power includes: silicon steel sheet loss power, keyway loss power, and stator core fault tooth loss power.

[0022] Secondly, this application also provides a temperature rise measurement system, including: a local excitation magnet core, a circulating current elimination core, a first power analyzer, a second power analyzer, and a processing module; the local excitation magnet core is placed on the teeth on both sides of the faulty teeth on the stator core, the faulty teeth are on the first lamination of the stator core, and the circulating current elimination core is placed on the second lamination; the first power analyzer is placed in the circuit formed by the local excitation magnet core and the first lamination; the second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination.

[0023] The processing module is used to: apply a standard local excitation frequency to the faulty tooth, calculate the first magnetic flux density power based on the readings of the first power analyzer and the second power analyzer; and calculate the standard magnetic flux density power based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0024] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0025] In one embodiment, the faulty tooth is the tooth in the stator core where the faulty tooth is indicated by the preset system, and a preset number of teeth on both sides.

[0026] 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 perform the following steps:

[0027] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0028] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0029] In one embodiment, the faulty tooth is the tooth in the stator core where the faulty tooth is indicated by the preset system, and a preset number of teeth on both sides.

[0030] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0031] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0032] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0033] In one embodiment, the faulty tooth is the tooth in the stator core where the faulty tooth is indicated by the preset system, and a preset number of teeth on both sides.

[0034] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0035] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0036] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0037] In one embodiment, the faulty tooth is the tooth in the stator core where the faulty tooth is indicated by the preset system, and a preset number of teeth on both sides.

[0038] The aforementioned method, system, computer equipment, computer-readable storage medium, and computer program product for measuring the local excitation temperature rise of stator core faults are described above. The method is applied to a temperature rise measurement system, which includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer. The local excitation core is placed on the teeth on both sides of the faulty tooth on the stator core, the faulty tooth being on the first lamination of the stator core. The circulating current elimination core is placed on the second lamination. The first power analyzer is placed in the circuit formed by the local excitation core and the first lamination. The second power analyzer is placed on the circulating current elimination core and the second lamination. On the circuit formed by laminations; the method includes: applying a standard local excitation frequency to the faulty tooth, calculating a first magnetic flux density power based on the readings of a first power analyzer and a second power analyzer; calculating a standard magnetic flux density power based on the first magnetic flux density power, the standard local excitation frequency, and a target local excitation frequency; applying the target local excitation frequency to the faulty tooth, calculating a second magnetic flux density power based on the readings of the first power analyzer and a second power analyzer; when the second magnetic flux density power equals the standard magnetic flux density power, performing a temperature rise measurement for a preset time to obtain the standard local excitation temperature rise of the faulty tooth. By measuring and calculating the power of the faulty tooth, and through the conversion between the power of the faulty tooth at a non-standard excitation frequency and the power of the faulty tooth at a standard excitation frequency, the standard local excitation temperature rise of the faulty tooth of the stator core can be measured at a non-standard excitation frequency, thereby directly determining whether there is a fault in the stator core through the stator core fault judgment standard. Attached Figure Description

[0039] 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.

[0040] Figure 1 This is a diagram illustrating the application environment of a standard local excitation temperature rise measurement method for stator core faults in one embodiment.

[0041] Figure 2 This is a flowchart illustrating a standard local excitation temperature rise measurement method for stator core faults in one embodiment.

[0042] Figure 3 This is a schematic diagram of a local excitation method for the stator core in one embodiment;

[0043] Figure 4 This is a schematic diagram of the equivalent resistance of the stator core local excitation method in one embodiment;

[0044] Figure 5 This is a circuit diagram of a stator core fault circuit in one embodiment;

[0045] Figure 6 This is a circuit diagram of the normal circuit of the stator core in one embodiment;

[0046] Figure 7 This is a flowchart illustrating the standard local excitation temperature rise measurement method for stator core faults in another embodiment.

[0047] Figure 8 This is a schematic diagram of the temperature rise measurement system in one embodiment;

[0048] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] The stator core fault standard local excitation temperature rise measurement method provided in this application embodiment can be applied to, for example... Figure 1In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104, or it can be located in the cloud or on another network server.

[0052] Specifically, terminal 102 has a temperature rise measurement system, which includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer; the local excitation core is placed on the teeth on both sides of the faulty tooth on the stator core, the faulty tooth is on the first lamination of the stator core, and the circulating current elimination core is placed on the second lamination; the first power analyzer is placed in the circuit formed by the local excitation core and the first lamination; the second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination; server 104 receives the readings of the first power analyzer and the second power analyzer transmitted by terminal 102. After reading the analyzer readings, the following steps are performed sequentially: After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency, the standard magnetic flux density power is calculated; after applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; when the second magnetic flux density power equals the standard magnetic flux density power, a temperature rise measurement is performed for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0053] Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, drones, low-altitude aircraft, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, and projection equipment. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted displays. Head-mounted displays can be virtual reality (VR) devices, augmented reality (AR) devices, and smart glasses. Server 104 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0054] In one exemplary embodiment, such as Figure 2As shown, a method for measuring the local excitation temperature rise of a stator core fault is provided. Taking the application of this method to server 104 as an example, the temperature rise measurement system applied to terminal 102 includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer. The local excitation core is placed on the teeth on both sides of the faulty tooth on the stator core, and the faulty tooth is on the first lamination of the stator core. The circulating current elimination core is placed on the second lamination. The first power analyzer is placed in the circuit formed by the local excitation core and the first lamination. The second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination.

[0055] One method is localized excitation, used to detect localized faults in the stator core of large generators. Its core involves using a localized excitation core, connected across the tooth to be tested, and applying a high-frequency power supply to generate a concentrated magnetic flux, precisely heating the faulty tooth. For example... Figure 2 The schematic diagram of the stator core local excitation method shown illustrates that the stator core 318 includes multiple layers of laminations arranged sequentially along its axial direction. Each lamination 300 has teeth 308 on its inner side. The laminations 300 are cylindrical, and each layer has teeth on its inner side, located near the central axis of the lamination. The multiple layers of laminations are stacked along the central axis to form the stator core. A local excitation core 304 spans across the stator core teeth 308 on both sides of the faulty tooth 310 in the stator core 318. Two windings are wound on the local excitation core 304: an excitation winding 302 and a measurement winding 306. The stator core 318 also includes stator core teeth 308, a stator core yoke 312, a stator core yoke height 314, and a stator core tooth width 316. The excitation winding 302 is used to connect to a high-frequency power supply to locally excite the faulty tooth, and the measuring winding 306 is used to connect to a voltmeter to measure the generated voltage of the faulty tooth.

[0056] For example, a high-frequency power supply is connected to the excitation winding of the local excitation core, and a voltmeter is connected to the measuring winding of the local excitation core. With only one turn in the measuring winding, the voltage output by the measuring winding is equal to the fault tooth voltage. To accurately determine whether a fault tooth truly exists, the fault tooth voltage generated by the local excitation method needs to be equal to the fault tooth voltage generated by the iron loss test. Specifically, in the iron loss test, a 50Hz excitation frequency is applied to the fault tooth, bringing the magnetic induction intensity of the stator core yoke to a saturation level of 1.4T. If a fault tooth exists on the stator core, a fault current loop will be generated inside the fault tooth. The formula for calculating the fault tooth voltage in the iron loss test is as follows:

[0057]

[0058] in, The faulty tooth voltage generated by the iron loss test. The circuit resistance of the faulty tooth. The operating frequency during the iron loss test. The saturation magnetic flux density Let be the area of ​​the yoke portion of the stator core, and This refers to the length of the teeth in the stator core. This refers to the height of the yoke of the stator core.

[0059] In the local excitation measurement method, a local excitation core is placed across the two sides of the faulty tooth in the stator core. By ensuring that the voltage induced on the faulty tooth using local excitation is the same as that in the iron loss test, the same temperature rise can be obtained. By judging the magnitude of the temperature rise, the presence of the faulty tooth can be determined. The formula for calculating the induced voltage on the faulty tooth using the local excitation method is:

[0060]

[0061] in, Induced voltage in faulty teeth using local excitation method The frequency of the high-frequency power supply connected to the excitation winding. The magnetic flux density of the locally excited magnetic core. Let be the area of ​​the teeth of the stator core, and This refers to the tooth width of the stator core.

[0062] Generally, to ensure that the induced voltage of the faulty teeth in the local excitation method is the same as that in the iron loss test, the excitation frequency applied to the faulty teeth of the stator core should be the same as the magnetic induction intensity of the stator core yoke. However, for large steam turbine generators, the yoke-to-tooth ratio is often around 8 to 10. Therefore, when , At this time, the area of ​​the yoke portion of the iron core is typically 8 to 10 times the area of ​​the tooth portion of the iron core. And when... achieve At that time, the local excitation core reaches a pre-saturation state. If the intensity is further increased... If this happens, the local excitation core will quickly enter a saturation state, leading to overheating. Therefore, in order to increase the voltage of the tooth section with local excitation faults... , making It is necessary to increase the frequency of the high-frequency power supply. Alternatively, increase the contact area between the teeth of the local excitation core and the stator core. and frequency When raised, the contact area of ​​the teeth Decrease; frequency When adjusted downwards, the contact area of ​​the teeth... Increase.

[0063] For example, based on the Electromagnetic Core Defect Detector (ELCID), the faulty teeth of the core are initially identified, and a stator core fault simulation model is established. Based on the stator core fault simulation model, a stator core fault simulation data table is generated. Based on the stator core fault simulation data table, the number of teeth on one side of the local excitation core that can meet the preset conditions is determined. The local excitation core is placed on the teeth on both sides of the faulty teeth on the stator core, the faulty teeth are on the first lamination of the stator core, and the circulating current elimination core is placed on the second lamination.

[0064] The circulating current eliminator core has the same shape and mass as the local excitation core. It also has excitation windings and measuring windings. The excitation windings are connected to a high-frequency power supply to locally excite the tooth corresponding to the faulty tooth, and the measuring windings are connected to a voltmeter to measure the generated voltage. Furthermore, the excitation windings on the circulating current eliminator core and the local excitation core have the same number of turns (402) but opposite directions. This ensures that the circulating current eliminator core and the local excitation core generate magnetomotive forces of equal magnitude and opposite direction, resulting in a total magnetomotive force of zero across the stator windings of each phase, thus eliminating circulating current.

[0065] For example, based on the pre-derived stator core simulation data table, it is known that the temperature safety margin of a 3-tooth core is relatively small, requiring at least a 4-tooth core. However, 5 teeth or more significantly increase weight and decrease magnetic flux efficiency, necessitating the use of counterweights for core installation tools. Therefore, a 4-tooth locally excited core is used. In this case, the target local excitation frequency required for detecting stator core faults using the local excitation method is 150Hz, ensuring a certain excitation margin during the stator core's local excitation process. When the target local excitation frequency is applied to the faulty tooth, the magnetic flux density of the locally excited core reaches 1.4T, while the magnetic flux density of the stator core is only 0.56T.

[0066] The method includes steps 202 to 204. Wherein:

[0067] Step 202: After applying a standard local excitation frequency to the faulty tooth, calculate the first magnetic flux density power based on the readings of the first power analyzer and the second power analyzer; calculate the standard magnetic flux density power based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0068] Among them, the locally excitation core, due to its shape resembling a "C", can also be called a C-type core. A power analyzer is a precision electronic measuring instrument used for high-precision measurement of electrical power and other related electrical parameters. The first power analyzer can measure the total power loss in the stator core fault circuit, and the second power analyzer can measure the total power loss in the stator core normal circuit. Since the iron loss method uses a 50Hz excitation frequency, 50Hz is used as the standard locally excitation frequency. When the standard locally excitation frequency is applied to the faulty teeth, and the stator core yoke can reach a saturation magnetic flux density of 1.4T, the standard locally excitation temperature rise of the faulty teeth can be measured. The first magnetic flux density power is the power generated when the magnetic flux density of the core yoke only reaches 0.56T after applying the standard 50Hz locally excitation frequency to the faulty teeth of the stator core. The standard magnetic flux density power is the power generated when the magnetic flux density of the core yoke reaches 1.4T after applying the standard 50Hz locally excitation frequency to the faulty teeth of the stator core.

[0069] For example, when a standard local excitation frequency of 50Hz is applied to the faulty tooth, the magnetic flux density of the local excitation core reaches 1.4T, indicating saturation. However, the magnetic flux density of the stator core yoke is only 0.56T. The power loss of the faulty tooth at this point is taken as the first magnetic flux density power. Based on the first magnetic flux density power, which is calculated at the standard local excitation frequency of 50Hz, the magnetic flux density of the stator core yoke at this point is the active power of the faulty tooth that should be generated when the magnetic flux density of the stator core yoke reaches 1.4T and saturation, but the magnetic flux density of the stator core yoke is only 0.56T. At this point, it is necessary to calculate the active power of the faulty tooth that should be generated when the magnetic flux density of the stator core yoke reaches 1.4T and saturation. This active power of the faulty tooth is taken as the standard magnetic flux density power.

[0070] Specifically, the magnetic flux density of the stator core yoke at the standard local excitation frequency and the target local excitation frequency is obtained. Based on the relationship between the magnetic flux density of the stator core yoke at the standard and target local excitation frequencies and the standard and target local excitation frequencies, the objective function is obtained. The first magnetic flux density power is then substituted into the objective function to calculate the standard magnetic flux density power.

[0071] Step 204: After applying the target local excitation frequency to the faulty tooth, calculate the second magnetic flux density power based on the readings of the first power analyzer and the second power analyzer; when the second magnetic flux density power is equal to the standard magnetic flux density power, perform a temperature rise measurement for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0072] The target local excitation frequency is 150Hz, which is the local excitation frequency required to detect stator core faults using the local excitation method when a 4-tooth local excitation core is used. The second magnetic flux density power is the power generated in the faulty tooth when a local excitation frequency of 150Hz is applied to the faulty tooth of the stator core.

[0073] For example, by using a locally excitation core and circulating current to eliminate the stator core, when the target local excitation frequency is applied to the faulty tooth, both the magnetic flux density of the locally excitation core and the magnetic flux density of the stator core yoke reach 1.4T saturation. By continuously receiving the readings from the first power analyzer and the second power analyzer and calculating the second magnetic flux density power, when the second magnetic flux density power equals the standard magnetic flux density power, it is equivalent to the work done at this time being the same as the work done to achieve a magnetic flux density of 1.4T in the stator core yoke after applying a standard local excitation frequency of 50Hz to the faulty tooth. At this point, the standard local excitation temperature rise of the faulty tooth in the stator core can be obtained by measuring the temperature rise of the stator core for 45 minutes.

[0074] In the aforementioned standard method for measuring the local excitation temperature rise of stator core faults, the method is applied to a temperature rise measurement system. The temperature rise measurement system includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer. The local excitation core is placed on the teeth on both sides of the faulty tooth on the stator core, the faulty tooth being on the first lamination of the stator core. The circulating current elimination core is placed on the second lamination. The first power analyzer is placed in the circuit formed by the local excitation core and the first lamination. The second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination. The method includes: After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. The standard magnetic flux density power is then calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency. After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power equals the standard magnetic flux density power, a temperature rise measurement is performed for a preset time to obtain the standard local excitation temperature rise of the faulty tooth. By measuring and calculating the power of the faulty tooth, and by converting between the power of the faulty tooth at a non-standard excitation frequency and the power at a standard excitation frequency, the standard local excitation temperature rise of the faulty tooth in the stator core can be measured at a non-standard excitation frequency. This allows for direct determination of whether a fault exists in the stator core using stator core fault determination standards.

[0075] In one embodiment, after applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. This includes: after applying the standard local excitation frequency to the faulty tooth, receiving the readings of the first power analyzer and the second power analyzer; using the reading of the first power analyzer as the total loss power of the stator core fault circuit; using the reading of the second power analyzer as the total loss power of the stator core normal circuit; and calculating the difference between the total loss power of the stator core fault circuit and the total loss power of the stator core normal circuit to obtain the first magnetic flux density power.

[0076] The first power analyzer is placed in the stator core fault circuit consisting of the local excitation core and the first lamination; the second power analyzer is placed in the stator core normal circuit consisting of the circulating current elimination core and the second lamination. Therefore, the reading of the first power analyzer is the total power loss of the stator core fault circuit; the reading of the second power analyzer is the total power loss of the stator core normal circuit. The first magnetic flux density power is the difference between the total power loss of the stator core fault circuit and the total power loss of the stator core normal circuit.

[0077] In this embodiment, by applying a standard local excitation frequency of 50Hz to the faulty teeth of the stator core, and using a first power analyzer and a second power analyzer to measure the total power loss of the faulty core circuit and the normal core circuit respectively, the difference between the two is calculated as the first magnetic flux density power. This can accurately obtain the power loss generated by the faulty teeth of the stator core under specific excitation conditions, and improve the accuracy and reliability of subsequent standard local excitation temperature rise measurement of stator core faults.

[0078] In one embodiment, the total power loss of the stator core fault circuit includes: local excitation core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke power loss, stator core normal yoke power loss, silicon steel sheet power loss, keyway power loss, and stator core fault tooth power loss; the total power loss of the stator core normal circuit includes: circulating current elimination core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke power loss, and stator core normal yoke power loss; the first magnetic flux density power includes: silicon steel sheet power loss, keyway power loss, and stator core fault tooth power loss.

[0079] For example, such as Figure 4 The diagram shown illustrates the equivalent resistance of the local excitation method. For localized excitation of the core magnetic reluctance, For excitation leakage reluctance, , For local excitation of the air gap magnetic reluctance of the magnetostatic core, , For stator core tooth reluctance. For stator core bypass reluctance, For normal stator core magnetic reluctance, The faulty stator core reluctance. The faulty leakage magnetic reluctance, The magnetomotive force is the excitation current. The fault current magnetomotive force. Figure 4 Converting to a planar circuit diagram, we get: Figure 5 The stator core fault circuit shown is as follows Figure 6 The circuit diagram shown is for the normal circuit of the stator core. Figure 5 excitation coil resistor Excitation coil leakage reactance and power supply voltage Combination correspondence Figure 4 In For excitation current magnetomotive force and For excitation leakage reluctance, and Combination correspondence Figure 4 In For local excitation, the core magnetic reluctance and the equivalent reactance of the air gap are... correspond Figure 4 In , For localized excitation, the air gap magnetic reluctance of the core is equal to the equivalent resistance of normal core losses. and normal iron core magnetizing reactance Combination correspondence Figure 4 Stator core tooth reluctance , , and Combination correspondence Figure 4 Stator core bypass magnetic reluctance Equivalent resistance of faulty iron core loss and faulty iron core excitation reactor Combination correspondence Figure 4 Faulty stator core magnetic reluctance Normal core loss equivalent resistance and normal iron core magnetizing reactance Combination correspondence Figure 4 Normal stator core magnetic reluctance , correspond The fault current magnetomotive force, The equivalent resistance of the fault circuit loss. For the leakage reactance of the faulty circuit, This is the keyway resistor.

[0080] like Figure 5 The circuit diagram of the stator core fault circuit shown can be used to analyze all the iron losses and fault circuit losses in the diagram. Therefore, the formula for calculating the total power loss of the stator core fault circuit is:

[0081]

[0082] in, This represents the total power loss in the stator core fault circuit. To reduce power loss in the localized excitation core, For stator core tooth loss power, To bypass power loss of stator core, For stator core fault yoke loss power, This represents the normal stator core yoke loss power. For the power loss of silicon steel sheets, For keyway power loss, This refers to the power loss due to a stator core fault.

[0083] Using the equivalent resistance of iron core yoke loss and core yoke excitation reactance Alternative Figure 4 The faulty loop in the middle forms, as follows Figure 6 The circuit diagram of the normal circuit of the stator core shown can be used to analyze all iron losses and normal circuit losses. The formula for calculating the total power loss of the normal circuit of the stator core is as follows:

[0084]

[0085] in, This represents the total power loss in the normal circuit of the stator core.

[0086] The formula for calculating the first magnetic flux density power is:

[0087]

[0088] At this point, the total power loss of the stator core fault circuit is subtracted from the total power loss of the stator core normal circuit to obtain the difference between the total power loss of the faulty stator core and the total power loss of the normal stator core. During the calculation, the total power loss of the normal stator core includes circulating current elimination core loss power, stator core tooth loss power, stator core bypass loss power, and stator core fault yoke loss power. All of these are removed, and the result is the first magnetic flux density power. When the power supply frequency and stator core magnetic flux density change, under the same voltage... , , They will change in sync. , , The impact of fault circuit shunting will vary. The length of a fault circuit is typically only a few millimeters, less than 1 / 10 the length of a stator core section. Therefore, the impact of fault circuit shunting is relatively small, and its effect on active power variation is minimal.

[0089] In this embodiment, by analyzing in detail the composition of the total power loss in the normal circuit of the stator core and the total power loss in the faulty circuit of the stator core, and accurately calculating the difference between the two, the power loss of the faulty teeth of the stator core under specific excitation conditions, namely the first magnetic flux density power, can be accurately obtained. The accurate power loss measurement provides important data support for subsequent judgment on whether there is a fault in the stator core and for measuring its local excitation temperature rise.

[0090] In one embodiment, the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency. This includes: obtaining the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying the standard local excitation frequency to the faulty tooth; confirming, based on preset simulation data, that the magnetic flux density of the second stator core yoke obtained when the target local excitation frequency is applied to the faulty tooth is the same as the magnetic flux density of the local excitation core; calculating the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke and the magnetic flux density of the second stator core yoke are the same after applying the standard local excitation frequency to the faulty tooth; and using the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0091] For example, the magnetic flux density of the local excitation core after applying a standard local excitation frequency of 50Hz to the faulty tooth is 1.4T and the magnetic flux density of the first stator core yoke is 0.56T. Based on preset simulation data, it is confirmed that the magnetic flux density of the second stator core yoke of 1.4T obtained when the target local excitation frequency is applied to the faulty tooth is the same as the magnetic flux density of the local excitation core of 1.4T.

[0092] For example, a 50Hz standard local excitation is applied to the faulty teeth of the stator core, causing the magnetic flux density of the yoke of the locally excited core to reach 1.4T, while the magnetic flux density of the stator core yoke is 0.56T. The standard excitation power needs to be calculated when a 50Hz standard local excitation is applied to the faulty teeth of the stator core, causing both the magnetic flux density of the locally excited core yoke and the magnetic flux density of the stator core yoke to reach 1.4T. First magnetic flux density power. This means that the faulty tooth is still functioning. Proportional to the square of the magnetic flux density, the active power of the standard fault tooth at 1.4T and 50Hz can be calculated based on the magnetic flux density of the first stator core yoke and the second stator core yoke, i.e., the standard magnetic flux density power. The formula for calculating the standard magnetic flux density power is as follows:

[0093]

[0094] in, The standard fault tooth active power, i.e., standard magnetic flux density power, is at 1.4T and 50Hz. = , The active power of the faulty tooth at 0.56T and 50Hz is the first magnetic flux density power.

[0095] In this embodiment, by forming an objective function based on the square proportional relationship between the first magnetic flux density power and the magnetic flux density, the standard magnetic flux density power under standard excitation conditions (1.4T, 50Hz) is accurately calculated. This provides an accurate conversion benchmark for converting the temperature rise of the stator core fault tooth measured at non-standard excitation frequencies into the temperature rise at the standard excitation frequency, thereby ensuring the accuracy and reliability of the measurement results.

[0096] In one embodiment, the method further includes: determining whether the faulty tooth has failed based on the standard local excitation temperature rise; and, if the faulty tooth has failed, determining the degree of heating of the faulty tooth.

[0097] For example, a temperature rise measurement is performed for 45 minutes to obtain the temperature rise of the faulty tooth in the stator core. Based on the standard local excitation temperature rise, the stator core fault judgment standard is used to directly determine whether the faulty tooth has failed; if the faulty tooth is confirmed to have failed, the degree of heating of the faulty tooth is determined based on the standard local excitation temperature rise.

[0098] In this embodiment, by applying temperature rise measurements to the faulty teeth of the stator core for a certain period of time, and using the acquired temperature rise data in conjunction with the standard local excitation temperature rise, and applying established fault judgment criteria, it is possible to quickly and accurately determine whether the faulty teeth have a fault. Once the faulty teeth are confirmed to be faulty, the degree of heating of the faulty teeth can be determined based on the correspondence between the standard local excitation temperature rise and the degree of heating. This provides a crucial basis for subsequent in-depth analysis and repair of stator core faults, and helps to take timely and effective measures to ensure the normal operation of the equipment.

[0099] The following is for reference. Figure 7 The present application will further illustrate the method for measuring the local excitation temperature rise of stator core faults using a specific embodiment.

[0100] Taking a generator as an example, the area of ​​the stator core yoke is typically 9.1 times the area of ​​the tooth section. A high-frequency power supply is connected to the excitation winding of a locally excitable core, and a voltmeter is connected to the measuring winding of the locally excitable core. With only one turn in the measuring winding, the voltage output by the measuring winding is equal to the voltage of the fault tooth. To accurately determine whether a fault tooth truly exists, the voltage of the fault tooth generated by the local excitation method must be equal to the voltage of the fault tooth generated by the iron loss test. Specifically: In the iron loss test, the stator core yoke is excited until the magnetic induction intensity reaches 1.4T. If a fault tooth exists on the stator core, a fault current loop will be generated inside the fault tooth. The formula for calculating the voltage of the fault tooth in the iron loss test is as follows:

[0101]

[0102] in, The faulty tooth voltage generated by the iron loss test. The circuit resistance of the faulty tooth. The operating frequency during the iron loss test. It represents the magnetic flux density. Let be the area of ​​the yoke portion of the stator core, and This refers to the length of the teeth in the stator core. This refers to the height of the yoke of the stator core.

[0103] In the local excitation measurement method, a local excitation core is placed across the two sides of the faulty tooth in the stator core. By ensuring that the voltage induced at the faulty tooth by local excitation is the same as that in the iron loss test, the same temperature rise as in the iron loss test can be obtained. By judging the magnitude of the temperature rise, the presence of the faulty tooth can be determined. The formula for calculating the induced voltage at the faulty tooth using the local excitation method is:

[0104]

[0105] in, Induced voltage in faulty teeth using local excitation method The frequency of the high-frequency power supply connected to the excitation winding. The magnetic flux density of the locally excited magnetic core. Let be the area of ​​the teeth of the stator core, and This refers to the tooth width of the stator core.

[0106] Generally, the induced voltage at the fault tooth in the local excitation measurement method and the induced voltage at the fault tooth in the iron loss test should use the same excitation frequency and magnetic induction intensity. However, for large steam turbine generators, the yoke-to-tooth ratio is often around 8 to 10. Therefore, when , At this time, the area of ​​the yoke portion of the iron core is typically 8 to 10 times the area of ​​the tooth portion of the iron core. And when... achieve At that time, the local excitation core reaches a pre-saturation state. If the intensity is further increased... If this happens, the local excitation core will quickly enter a saturation state, leading to overheating. Therefore, in order to increase the voltage of the tooth section with local excitation faults... , making It is necessary to increase the frequency of the high-frequency power supply. Alternatively, increase the contact area between the teeth of the local excitation core and the stator core. and frequency When raised, the contact area of ​​the teeth Decrease; frequency When adjusted downwards, the contact area of ​​the teeth... Increase.

[0107] In engineering practice, it has been found that simply increasing the frequency results in a large temperature difference error, and increasing the frequency makes it difficult for the faulty tooth to obtain the same heating power as required by the standard. Specifically, the standard requires the heating power measured at an excitation frequency of 50Hz and a yoke magnetic flux of 1.4T as the standard heating power. Therefore, a method is needed to measure the standard temperature rise at different frequencies. The stator core fault local excitation temperature rise measurement method of this application is applied to a temperature rise measurement system, which includes: a local excitation core, a circulating current elimination core, a first power analyzer, and a second power analyzer. The local excitation core is placed on the teeth on both sides of the faulty tooth on the stator core, the faulty tooth is on the first lamination of the stator core, and the circulating current elimination core is placed on the second lamination. The first power analyzer is placed in the circuit formed by the local excitation core and the first lamination. The second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination. Based on the electromagnetic core defect detector (ELCID), the tooth where the core fault is located is initially determined. Since the teeth of the two adjacent teeth of the faulty tooth heat up during local excitation, in order to reduce the impact, the detection teeth under the local excitation core need to be expanded to two teeth, with the two teeth being the faulty teeth of the stator core. A local excitation core is placed across the teeth on both sides of the suspected faulty tooth to locally excite the faulty tooth. The local excitation core and the circulating current eliminator core have two windings: an excitation winding and a measurement winding, which are connected to a high-frequency power supply and a voltmeter, respectively. The circulating current eliminator core and the local excitation core are placed parallel to each other to eliminate circulating current. The circulating current eliminator core and the local excitation core are made of the same material and have opposite winding directions.

[0108] A stator core fault simulation model was established. Preset parameter settings were input into the model to gradually increase the number of teeth on one side of the local excitation core from 1. The excitation frequency, generator core tooth loss, generator core tooth temperature rise over 45 minutes, temperature at an assumed ambient temperature of 40℃, and local excitation core magnetic flux were obtained. Through the magnetic flux of the fault area, bypass magnetic flux, and bypass magnetic flux percentage, a stator core fault simulation data table was established.

[0109] The simulation data of stator core faults are shown in Table 1.

[0110] Table 1

[0111]

[0112] The permissible temperature for stator winding insulation is generally 130 degrees Celsius. Based on the stator core simulation data table above, it can be seen that when the ambient temperature is assumed to be 40 degrees Celsius, the temperature after a 45-minute temperature rise measurement should not exceed 130 degrees Celsius. However, the temperature safety margin of a 3-tooth local excitation core is relatively small, and at least a 4-tooth local excitation core should be used. 5 teeth or more significantly increase the weight and decrease the magnetic flux efficiency, and the installation tools for the local excitation core require counterweights. Considering all factors, a 4-tooth local excitation core is selected, and the frequency is increased to 150Hz to ensure a certain excitation margin during the test.

[0113] A standard local excitation frequency of 50Hz is applied to the faulty teeth of the stator core. At this time, the magnetic flux density of the stator core yoke is saturated when the local excitation core magnetic flux density reaches 1.4T, but the magnetic flux density of the stator core yoke is only 0.56T. The first power analyzer measures the total power loss of the faulty stator core circuit, and the second power analyzer measures the total power loss of the normal stator core circuit. The difference between the total power loss of the faulty core circuit and the total power loss of the normal stator core circuit is calculated. This difference represents the active power of the faulty teeth at 50Hz, i.e., the first magnetic flux density power. The formula for calculating the first magnetic flux density power is as follows:

[0114]

[0115]

[0116]

[0117] in, This represents the total power loss in the stator core fault circuit. To reduce power loss in the localized excitation core, For stator core tooth loss power, To bypass power loss of stator core, For stator core fault yoke loss power, This represents the normal stator core yoke loss power. For the power loss of silicon steel sheets, For keyway power loss, This refers to the power loss due to a stator core fault. This represents the total power loss in the normal stator core circuit. This is the first magnetic flux density power.

[0118] The standard magnetic flux density power is calculated using the following formula:

[0119]

[0120] in, The standard fault tooth active power, i.e., standard magnetic flux density power, is at 1.4T and 50Hz. = , The active power of the faulty tooth at 0.56T and 50Hz is the first magnetic flux density power.

[0121] After calculating the standard magnetic flux density power, a local excitation frequency of 150Hz is applied to the faulty teeth of the stator core. The readings from the first and second power analyzers are continuously received, and the second magnetic flux density power is calculated. When the second magnetic flux density power equals the standard magnetic flux density power, a temperature rise measurement is performed for 45 minutes to obtain the temperature rise of the standard faulty teeth in the stator core. This standard faulty tooth temperature rise is used to determine whether a fault exists in the faulty teeth using the stator core as a standard.

[0122] 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.

[0123] Based on the same inventive concept, this application also provides a temperature rise measurement system for implementing the above-described method for measuring the temperature rise of a stator core fault under standard local excitation. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more temperature rise measurement system embodiments provided below can be found in the limitations of the stator core fault standard local excitation temperature rise measurement method described above, and will not be repeated here.

[0124] In one exemplary embodiment, such as Figure 8 As shown, a temperature rise measurement system is provided, including: a local excitation core 804, a circulating current elimination core 806, a first power analyzer, a second power analyzer, and a processing module; the local excitation core 804 is placed on the teeth on both sides of the faulty tooth 808 on the stator core, the faulty tooth is on the first lamination 810 of the stator core, and the circulating current elimination core 806 is placed on the second lamination 802; the first power analyzer is placed in the circuit formed by the local excitation core 804 and the first lamination 810; the second power analyzer is placed in the circuit formed by the circulating current elimination core and the second lamination 802.

[0125] The processing module is used to: apply a standard local excitation frequency to the faulty tooth, calculate the first magnetic flux density power based on the readings of the first power analyzer and the second power analyzer; and calculate the standard magnetic flux density power based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0126] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0127] In one embodiment, the faulty tooth is the tooth in the stator core where the faulty tooth is indicated by the preset system, and a preset number of teeth on both sides.

[0128] For example, based on the electromagnetic core defect detector (ELCID), the tooth where the core fault is located is initially determined. Since the teeth adjacent to the faulty tooth heat up during local excitation, in order to reduce the impact, the detection teeth under the locally excited core need to be enlarged to 2 teeth. The tooth where the stator core faulty tooth is located and the preset number of teeth on both sides are taken as the stator core faulty tooth.

[0129] In this embodiment, based on the initial positioning using ELCID, and considering the characteristic that the teeth adjacent to the faulty tooth will heat up during local excitation, the detection teeth under the local excitation core are expanded to two teeth, so that the faulty tooth is far away from the heated tooth, thereby ignoring the interference of the heated tooth on the judgment of the faulty tooth. This can improve the accuracy and reliability of determining the faulty tooth of the stator core, and provide a solid foundation for subsequent accurate measurement of the local excitation temperature rise of the stator core fault.

[0130] In one embodiment, the processing module is further configured to, after applying a standard local excitation frequency to the faulty tooth, receive the readings of a first power analyzer and a second power analyzer; use the reading of the first power analyzer as the total power loss of the stator core fault circuit; use the reading of the second power analyzer as the total power loss of the stator core normal circuit; and calculate the difference between the total power loss of the stator core fault circuit and the total power loss of the stator core normal circuit to obtain the first magnetic flux density power.

[0131] In one embodiment, the total power loss of the stator core fault circuit includes: local excitation core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke power loss, stator core normal yoke power loss, silicon steel sheet power loss, keyway power loss, and stator core fault tooth power loss; the total power loss of the stator core normal circuit includes: circulating current elimination core power loss, stator core tooth loss power, stator core bypass power loss, stator core fault yoke power loss, and stator core normal yoke power loss; the first magnetic flux density power includes: silicon steel sheet power loss, keyway power loss, and stator core fault tooth power loss.

[0132] In one embodiment, the processing module is further configured to obtain the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying a standard local excitation frequency to the faulty tooth; confirm, based on preset simulation data, that the magnetic flux density of the second stator core yoke obtained when the target local excitation frequency is applied to the faulty tooth is the same as the magnetic flux density of the local excitation core; calculate the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke and the magnetic flux density of the second stator core yoke are the same after applying a standard local excitation frequency to the faulty tooth; and use the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0133] In one embodiment, the processing module is further configured to determine whether the faulty tooth has failed based on the standard local excitation temperature rise; and if the faulty tooth is confirmed to have failed, to determine the degree of heating of the faulty tooth.

[0134] Each module in the aforementioned temperature rise measurement system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0135] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores stator core power calculation data. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a method for measuring the standard local excitation temperature rise of stator core faults.

[0136] Those skilled in the art will understand that Figure 8 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.

[0137] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0138] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0139] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0140] In one embodiment, when the processor executes the computer program, it further performs the following steps: after applying a standard local excitation frequency to the faulty tooth, it receives the readings of a first power analyzer and a second power analyzer; it uses the reading of the first power analyzer as the total power loss of the stator core fault circuit; it uses the reading of the second power analyzer as the total power loss of the stator core normal circuit; and it calculates the difference between the total power loss of the stator core fault circuit and the total power loss of the stator core normal circuit to obtain the first magnetic flux density power.

[0141] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying a standard local excitation frequency to the faulty tooth; confirming, based on preset simulation data, that the magnetic flux density of the second stator core yoke obtained when applying a target local excitation frequency to the faulty tooth is the same as the magnetic flux density of the local excitation core; calculating, based on the first magnetic flux density power, the magnetic flux density of the first stator core yoke, and the magnetic flux density of the second stator core yoke, the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke and the magnetic flux density of the second stator core yoke are the same after applying a standard local excitation frequency to the faulty tooth; and using the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0142] In one embodiment, when the processor executes the computer program, it also performs the following steps: determining whether the faulty tooth has failed based on the standard local excitation temperature rise; and, if the faulty tooth is confirmed to have failed, determining the degree of heating of the faulty tooth.

[0143] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0144] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0145] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0146] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: after applying a standard local excitation frequency to the faulty tooth, it receives the readings of a first power analyzer and a second power analyzer; it uses the reading of the first power analyzer as the total power loss of the stator core fault circuit; it uses the reading of the second power analyzer as the total power loss of the stator core normal circuit; and it calculates the difference between the total power loss of the stator core fault circuit and the total power loss of the stator core normal circuit to obtain the first magnetic flux density power.

[0147] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying a standard local excitation frequency to the faulty tooth; confirming, based on preset simulation data, that the magnetic flux density of the second stator core yoke obtained when applying a target local excitation frequency to the faulty tooth is the same as the magnetic flux density of the local excitation core; calculating, based on the first magnetic flux density power, the magnetic flux density of the first stator core yoke, and the magnetic flux density of the second stator core yoke, the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke and the magnetic flux density of the second stator core yoke are the same after applying a standard local excitation frequency to the faulty tooth; and using the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0148] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining whether the faulty tooth has failed based on the standard local excitation temperature rise; and, if the faulty tooth is confirmed to have failed, determining the degree of heating of the faulty tooth.

[0149] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0150] After applying a standard local excitation frequency to the faulty tooth, the first magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer; the standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency, and the target local excitation frequency.

[0151] After applying the target local excitation frequency to the faulty tooth, the second magnetic flux density power is calculated based on the readings of the first power analyzer and the second power analyzer. When the second magnetic flux density power is equal to the standard magnetic flux density power, the temperature rise is measured for a preset time to obtain the standard local excitation temperature rise of the faulty tooth.

[0152] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: after applying a standard local excitation frequency to the faulty tooth, it receives the readings of a first power analyzer and a second power analyzer; it uses the reading of the first power analyzer as the total power loss of the stator core fault circuit; it uses the reading of the second power analyzer as the total power loss of the stator core normal circuit; and it calculates the difference between the total power loss of the stator core fault circuit and the total power loss of the stator core normal circuit to obtain the first magnetic flux density power.

[0153] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the magnetic flux density of the local excitation core and the magnetic flux density of the first stator core yoke after applying a standard local excitation frequency to the faulty tooth; confirming, based on preset simulation data, that the magnetic flux density of the second stator core yoke obtained when applying a target local excitation frequency to the faulty tooth is the same as the magnetic flux density of the local excitation core; calculating, based on the first magnetic flux density power, the magnetic flux density of the first stator core yoke, and the magnetic flux density of the second stator core yoke, the magnetic flux density power that the faulty tooth should have when the magnetic flux density of the first stator core yoke and the magnetic flux density of the second stator core yoke are the same after applying a standard local excitation frequency to the faulty tooth; and using the magnetic flux density power that the faulty tooth should have as the standard magnetic flux density power.

[0154] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining whether the faulty tooth has failed based on the standard local excitation temperature rise; and, if the faulty tooth is confirmed to have failed, determining the degree of heating of the faulty tooth.

[0155] 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.

[0156] 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.

[0157] 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 stator core fault criterion local field excitation temperature rise measurement method, characterized by, The application is applied to a temperature rise measurement system, and the temperature rise measurement system comprises a local excitation core, a circulating current elimination core, a first power analyzer and a second power analyzer; the local excitation core is arranged on the tooth portion on both sides of a fault tooth portion of a stator core, the fault tooth portion is on a first punching sheet of the stator core, and the circulating current elimination core is arranged on a second punching sheet; the first power analyzer is arranged on a loop formed by the local excitation core and the first punching sheet; the second power analyzer is arranged on a loop formed by the circulating current elimination core and the second punching sheet; and the method comprises the following steps: After a standard local excitation frequency is applied to the fault tooth portion, a first magnetic flux density power is calculated according to readings of the first power analyzer and the second power analyzer; a standard magnetic flux density power is calculated based on the first magnetic flux density power, the standard local excitation frequency and a target local excitation frequency; After the target local excitation frequency is applied to the fault tooth portion, a second magnetic flux density power is calculated according to readings of the first power analyzer and the second power analyzer; when the second magnetic flux density power is equal to the standard magnetic flux density power, temperature rise measurement is performed for a preset time to obtain a standard local excitation temperature rise of the fault tooth portion.

2. The method of claim 1, wherein, The step of calculating the first magnetic flux density power according to the readings of the first power analyzer and the second power analyzer after the standard local excitation frequency is applied to the fault tooth portion comprises the following steps: After the standard local excitation frequency is applied to the fault tooth portion, readings of the first power analyzer and the second power analyzer are received; the reading of the first power analyzer is taken as a total loss power of a fault loop of the stator core; and the reading of the second power analyzer is taken as a total loss power of a normal loop of the stator core; The difference between the total loss power of the fault loop of the stator core and the total loss power of the normal loop of the stator core is calculated to obtain the first magnetic flux density power.

3. The method of claim 1, wherein, The step of calculating the standard magnetic flux density power based on the first magnetic flux density power, the standard local excitation frequency and the target local excitation frequency comprises the following steps: The local excitation core magnetic flux density and the first stator core yoke magnetic flux density after the standard local excitation frequency is applied to the fault tooth portion are obtained; It is confirmed based on preset simulation data that the second stator core yoke magnetic flux density obtained when the target local excitation frequency is applied to the fault tooth portion is the same as the local excitation core magnetic flux density; The fault tooth portion should have a magnetic flux density power when the first stator core yoke magnetic flux density is the same as the second stator core yoke magnetic flux density after the standard local excitation frequency is applied to the fault tooth portion, and the fault tooth portion should have a magnetic flux density power is taken as the standard magnetic flux density power based on the first magnetic flux density power, the first stator core yoke magnetic flux density and the second stator core yoke magnetic flux density.

4. The method of claim 1, wherein, The method further comprises the following steps: It is judged whether the fault tooth portion is faulty according to the standard local excitation temperature rise; In the case that it is confirmed that the fault tooth portion is faulty, the heating degree of the fault tooth portion is determined.

5. The method of claim 2, wherein, The total loss power of the stator core fault circuit comprises: local excitation core loss power, stator core tooth loss power, stator core bypass loss power, stator core fault yoke loss power, stator core normal yoke loss power, silicon steel sheet loss power, key groove loss power and stator core fault tooth loss power; the total loss power of the stator core normal circuit comprises: circulating current elimination core loss power, stator core tooth loss power, stator core bypass loss power, stator core fault yoke loss power and stator core normal yoke loss power; the first magnetic density power comprises: silicon steel sheet loss power, key groove loss power and stator core fault tooth loss power.

6. A temperature rise measurement system characterized by, Comprise: a local excitation core, a circulating current elimination core, a first power analyzer, a second power analyzer and a processing module; The local excitation core is arranged on the tooth portions on both sides of a fault tooth portion of a stator core, the fault tooth portion is on a first lamination of the stator core, and the circulating current elimination core is arranged on a second lamination; the first power analyzer is arranged on a circuit formed by the local excitation core and the first lamination; and the second power analyzer is arranged on a circuit formed by the circulating current elimination core and the second lamination. The processing module is configured to: after applying a standard local excitation frequency to the fault tooth portion, calculate a first magnetic density power according to readings of the first power analyzer and the second power analyzer; and based on the first magnetic density power, the standard local excitation frequency and a target local excitation frequency, calculate a standard magnetic density power; After applying the target local excitation frequency to the fault tooth portion, calculate a second magnetic density power according to readings of the first power analyzer and the second power analyzer; when the second magnetic density power is equal to the standard magnetic density power, perform temperature rise measurement for a preset time to obtain a local excitation temperature rise of the fault tooth portion.

7. The system of claim 6, wherein, The fault tooth portion is a tooth portion where a fault tooth portion of the stator core indicated by a preset system and a preset number of tooth portions on both sides of the fault tooth portion.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to implement the steps of the method in any one of claims 1 to 5.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 5.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 5. The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 5.

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