Off-line detection tool for turbonator rotor winding turn-to-turn short circuit fault

Abstract

The utility model provides an off-line detection tool for a turn-to-turn short circuit fault of a rotor winding of a steam turbine generator. The off-line detection tool comprises an insulating supporting rod, a plurality of conductive probes, a plug and a plurality of wires, a plurality of mounting holes are formed in the side wall of the insulating supporting rod and distributed at intervals in the length direction of the insulating supporting rod, the conductive probes are mounted in the mounting holes in a one-to-one correspondence mode, and the detection ends of the conductive probes extend out of the mounting holes. The plug is provided with a plurality of connecting ends, and two ends of each wire are respectively connected with the conductive probe and the connecting ends. Based on the radial vent holes originally existing in the turbonator rotor winding, extra workload generated by dismounting the slot wedge is not needed, the problems of turn-to-turn insulation damage and the like caused by dismounting the slot wedge are avoided, only the detection tool needs to be inserted into the vent holes during detection, the operation is simple, the accuracy is high, the detection process is safe, and the detection efficiency is high. The method can be widely applied to off-line detection of turbonator rotor winding turn-to-turn short circuit faults.

Description

Technical Field

[0001] This application belongs to the field of generator testing technology, specifically, it relates to an offline testing tool for inter-turn short circuit faults in the rotor windings of a steam turbine generator. Background Technology

[0002] Rotor winding inter-turn short circuits are a common generator fault that can affect the stable operation of the unit. This fault is mainly caused by substandard manufacturing processes, foreign metal objects, etc. In its early stages, inter-turn short circuit faults are not obvious, but as the fault progresses, it leads to increased rotor current, higher winding temperature, and rotor mechanical vibration. These phenomena all affect the unit's power production and service life, ultimately threatening the safe and stable operation of both the unit and the power grid. Therefore, developing an efficient and accurate diagnostic method for inter-turn short circuits in turbine generator rotor windings is of great significance.

[0003] In recent years, with the development of research techniques and methods, research on inter-turn short circuits in rotor windings continues to deepen. Based on whether the rotor is running, detection can be divided into online and offline types. Online monitoring mainly judges the problem by acquiring the unit's online operating parameters, including methods such as coil detection, excitation current, and shaft voltage. However, online diagnostic methods suffer from low sensitivity and susceptibility to many interference factors, and the technology is still under improvement. Offline diagnostics, while not able to acquire operating parameters in real time, avoids many interference factors and has a relatively higher accuracy rate, making it widely used by technical maintenance personnel.

[0004] Currently, offline diagnostic methods mainly include the no-load short-circuit test, DC resistance method, AC impedance and loss test, two-stage voltage balance method, repetitive pulse method, and open transformer method. Among these, the no-load short-circuit test, DC resistance method, and two-stage voltage balance method have relatively low sensitivity. The AC impedance and loss test results are affected by factors such as slot wedge installation process and residual magnetism of the rotor. Although the open transformer method can eliminate many interference factors and has high accuracy and sensitivity, it requires removing the rotor, which is labor-intensive. The repetitive pulse method is convenient to use and can determine the location of the short-circuit point in the slot, and has been widely used in recent years.

[0005] Once the faulty slot is identified offline, it is necessary to further determine which two or more turns the fault occurred between by measuring the voltage difference between the turns in the slot. Currently, this is generally done manually, using two metal probes to measure the voltage between each turn sequentially below the retaining ring or at the ventilation hole. This measurement method is not only labor-intensive and time-consuming, but it is also difficult to ensure good contact between the probes and each turn winding. In some cases, it may even cause metal foreign objects to enter the rotor or damage the inter-turn insulation. Therefore, it is essential to design a new offline detection tool for short-circuit faults between turns in turbine generator rotor windings that is easy to measure and safe and reliable. Utility Model Content

[0006] The technical problem addressed by this application is: how to provide an offline detection tool for short-circuit faults between turns in the rotor winding of a steam turbine generator that is easy to measure and safe and reliable.

[0007] This application provides an offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator, the offline detection tool comprising:

[0008] An insulating support rod, wherein a plurality of mounting holes are provided on the side wall of the insulating support rod, and the plurality of mounting holes are spaced apart along the length direction of the insulating support rod;

[0009] A plurality of conductive probes are mounted one-to-one in a plurality of mounting holes, and the probe ends of the conductive probes extend out of the mounting holes.

[0010] A plug having several connecting ends;

[0011] Several wires, each of which has its two ends connected to the conductive probe and the connection end, respectively.

[0012] Optionally, the insulating support rod is hollow inside and communicates with the mounting hole, and the wire is connected to the back of the conductive probe and led out from the inside of the insulating support rod along the length direction.

[0013] Optionally, the conductive probe is a spring-loaded conductive probe.

[0014] Optionally, the insulating support rod is made of plastic.

[0015] Optionally, the plug is a multi-core aviation plug.

[0016] This application provides an offline detection tool for inter-turn short-circuit faults in the rotor windings of a steam turbine generator, which has the following technical advantages:

[0017] Based on the radial ventilation holes that already exist in the rotor windings of steam turbine generators, there is no need to remove the slot wedges, thus avoiding the extra workload. This avoids problems such as damage to the inter-turn insulation caused by removing and installing slot wedges. During testing, the testing tool is simply inserted into the ventilation hole. The operation is simple, the accuracy is high, and the testing process is safe. It can be widely used for offline testing of inter-turn short circuit faults in the rotor windings of steam turbine generators. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator, according to one or more embodiments.

[0019] Figure 2This is a schematic diagram illustrating the use of an offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator, according to one or more embodiments.

[0020] The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0021] Insulating support rod-10, mounting hole-11, conductive probe-20, plug-30, wire-40, winding-100, ventilation hole-200, slot wedge-300. Detailed Implementation

[0022] 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.

[0023] Before describing the various embodiments of this application in detail, the technical concept of this application is first briefly described: Currently, measuring the inter-turn voltage of a turbine generator rotor winding suffers from problems such as inconvenience and safety. Therefore, this application provides an offline detection tool for inter-turn short-circuit faults in turbine generator rotor windings. Multiple conductive probes are spaced apart along the length of an insulating support rod. Each conductive probe is connected to a connector terminal of a plug via several wires. During testing, the insulating support rod is inserted into the radial ventilation holes of the rotor winding. By applying slight pressure, each conductive probe reliably contacts each layer of the rotor winding, thereby testing the voltage between adjacent windings. This testing process is convenient and safe. The specific principle of the offline detection tool for inter-turn short-circuit faults in turbine generator rotor windings of this application will be described below with reference to more embodiments.

[0024] Specifically, such as Figure 1 and Figure 2 As shown, the offline detection tool for inter-turn short circuit faults in the rotor winding of a steam turbine generator in this embodiment includes an insulating support rod 10, several conductive probes 20, a plug 30, and several wires 40. The side wall of the insulating support rod 10 has several mounting holes 11, which are spaced apart along the length of the insulating support rod 10. Several conductive probes 20 are installed in the mounting holes 11 one by one, and the detection end of the conductive probe 20 extends out of the mounting hole 11. The plug 30 has several connection ends. The two ends of each wire 40 are connected to the conductive probe 20 and the connection end, respectively. In this way, the electrical signal detected by the conductive probe 20 can be transmitted to the plug 30, and then further transmitted to the voltage measuring instrument for measurement through the plug 30.

[0025] In one or more embodiments, the interior of the insulating support rod 10 is hollow and communicates with the mounting hole 11. The wire 40 is connected to the back of the conductive probe 20 and leads out from the interior of the insulating support rod 10 along the length direction. This can prevent the wire 40 from contacting the winding and prevent damage to the wire 40.

[0026] For example, the insulating support rod 10 is made of plastic. For instance, the insulating support rod 10 is made of a hollow plastic tube, with several mounting holes 11 opened on the side wall of the hollow plastic tube. The conductive probes 20 are placed in each mounting hole 11 in a corresponding manner, and the wires 40 are connected to the back of each conductive probe 20, passing through one end of the hollow plastic tube. Each wire is then connected to each connection end of the plug 30, and the hollow plastic tube is then injection molded and sealed.

[0027] For example, each mounting hole 11 is on the same side of the insulating support rod 10 and faces the same direction. The distance between adjacent mounting holes 11 is equal to the distance between the centers of two adjacent turns of winding, which can ensure that the conductive probe 20 is aligned and close to each turn of winding during testing.

[0028] In one or more embodiments, the plug 30 is a multi-core aviation plug, the conductive probe 20 is a spring conductive probe, and the wire 40 is covered with an insulating layer.

[0029] like Figure 2 As shown, during measurement, a certain DC voltage is first applied to each turn of the generator rotor winding 100. The insulating support rod 10 is inserted into the radial ventilation hole 200 of the rotor winding, and each conductive probe 20 is aligned and pressed firmly against each turn of the winding 100, ensuring reliable contact. The plug 30 is connected to a voltage measuring instrument to measure the voltage difference between adjacent turns of the winding 100. When the voltage difference between a certain adjacent turn of the winding 100 is significantly less than the voltage differences between other adjacent turn of the winding 100, it can be determined that a short circuit occurs between those two turns of the winding 100. It should be noted that the slot wedge 300 does not need to be removed during testing, avoiding potential insulation damage and vibration degradation that may occur during the removal and installation of the slot wedge 300. This offline testing tool is low-cost and fast, achieving high diagnostic accuracy, and can be widely used for offline detection of inter-turn short circuit faults in turbine generator rotor windings.

[0030] The specific embodiments of this application have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and improvements can be made to these embodiments without departing from the principles and spirit of this application as defined by the claims and their equivalents, and such modifications and improvements should also be within the protection scope of this application.

Claims

1. An offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator, characterized in that, The offline detection tool includes: An insulating support rod, wherein a plurality of mounting holes are provided on the side wall of the insulating support rod, and the plurality of mounting holes are spaced apart along the length direction of the insulating support rod; A plurality of conductive probes are mounted one-to-one in a plurality of mounting holes, and the probe ends of the conductive probes extend out of the mounting holes. A plug having several connecting ends; Several wires, each of which has its two ends connected to the conductive probe and the connection end, respectively.

2. The offline detection tool for inter-turn short circuit faults in the rotor winding of a steam turbine generator according to claim 1, characterized in that, The insulating support rod is hollow inside and communicates with the mounting hole. The wire is connected to the back of the conductive probe and leads out from the inside of the insulating support rod along the length direction.

3. The offline detection tool for inter-turn short circuit faults in the rotor winding of a steam turbine generator according to claim 1, characterized in that, The conductive probe is a spring-loaded conductive probe.

4. The offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator according to claim 1, characterized in that, The insulating support rod is made of plastic.

5. The offline detection tool for inter-turn short-circuit faults in the rotor winding of a steam turbine generator according to claim 1, characterized in that, The plug is a multi-core aviation plug.

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