Fault monitoring device for cross-core screw of bulb tubular hydraulic generator
By combining a resistance voltage divider module and an infrared temperature sensor in the hydro generator, the problem of real-time monitoring of faults in the through-bolt of the turbine generator is solved. This enables efficient online detection of short-circuit faults between the through-bolt and the positioning rib, reducing detection costs and improving monitoring accuracy.
Patent Information
- Application Number
- CN202422977109.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-12-04
AI Technical Summary
Existing technologies make it difficult to achieve real-time monitoring of faults in the through-bolt of a axial-flow turbine generator, especially short-circuit faults between the through-bolt and the positioning rib, which are difficult to monitor online. Furthermore, existing methods are either expensive or lack sufficient sensitivity.
A bulb-type hydro turbine generator through-hole screw fault monitoring device is adopted. The through-hole screw and positioning rib are connected through the first and second resistance voltage divider modules. Combined with the data acquisition module, the current and voltage values are collected in real time, and the temperature change is monitored by the infrared temperature sensor to realize the real-time judgment and location of the short circuit point.
It enables timely detection of short-circuit faults in the through-bolt and positioning rib, reduces detection costs, improves monitoring sensitivity, and does not affect the safety of the generator structure, thus providing a basis for online monitoring applications.
Smart Images
Figure CN223513330U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fault monitoring technology, specifically to a fault monitoring device for the through-screw of a bulb-type hydro turbine generator. Background Technology
[0002] The stator core of a axial-flow turbine generator is composed of stacked silicon steel sheets. Through-bolts serve to fix the silicon steel sheets, and insulating material is placed between the through-bolts and the sheets to prevent eddy currents. However, the generator's internal environment is complex during operation, including high and low frequency vibrations, high voltage and strong electromagnetic fields, as well as conductive and corrosive contaminants such as metal dust from carbon brush wear and oil mist. Long-term mechanical vibration can cause wear on the insulating material, creating gaps between the through-bolts and the core, leading to contaminant accumulation and reduced insulation. In recent years, several axial-flow turbine generators have experienced short-circuit faults due to insulation damage to the through-bolts, causing the through-bolts to melt through the stator core and positioning ribs, sometimes even melting the stator core in contact with the through-bolts. The most severely damaged through-bolts are those directly opposite the positioning ribs. Therefore, online monitoring of the characteristics (such as current, voltage, and resistance values) of short-circuit faults formed between the screw, stator core, and positioning ribs can help achieve early warning of such faults.
[0003] In existing technologies, there are generally three types of methods for monitoring short-circuit faults between the through-hole screw and the positioning rib of a axial-flow turbine generator. The first is to measure the insulation resistance of the through-hole screw using a megohmmeter. The second is the iron loss test method, which involves winding high-power insulated wires around the generator stator core and injecting alternating current into the wires. The magnetic field generated by this current closes along the entire stator core, and the periodic alternation of the magnetic field generates heat loss in the core. The short-circuit point can be found by observing the internal temperature of the generator using an infrared thermometer. However, these two methods are only suitable for online monitoring of through-hole screw faults after the generator is shut down, and the testing costs are high. The third is the ELCID (Electromagnetic Core Detection) method, which uses portable equipment to generate an alternating local magnetic field between adjacent slots in the generator stator core. If there is a short circuit in the interlayer insulation of the stator core, a local fault current will be generated. However, this method can only detect short-circuit faults in the stator slots and is not sensitive enough to detect short-circuit faults between the through-hole screw and the positioning rib. Utility Model Content
[0004] This utility model provides a fault monitoring device for the through-bolt of a bulb-type hydro-generator, which solves the problems of difficulty in real-time monitoring of faults in the through-bolt of hydro-generators and difficulty in monitoring short-circuit faults between the through-bolt and the positioning rib in the prior art.
[0005] To achieve the above objectives, this utility model provides the following solution:
[0006] A bulb-type hydro-generator through-hole screw fault monitoring device includes a hydro-generator, a through-hole screw and a positioning rib installed inside the hydro-generator, a first resistance voltage divider module, a second resistance voltage divider module, and several data acquisition modules for collecting data. The first resistance voltage divider module is connected to one end of the through-hole screw and one end of the positioning rib, and the second resistance voltage divider module is connected to the other end of the through-hole screw and the other end of the positioning rib.
[0007] This invention uses a data acquisition module to collect the current and voltage values of the first and second resistor voltage divider modules in real time, and can determine in real time whether there is a short circuit between the through-core screw and the positioning rib. It can promptly report the short circuit between the through-core screw and the corresponding positioning rib inside the turbine generator to the staff, so that the staff can deal with the fault in time. When a short circuit loop is formed between the through-core screw and the positioning rib, the first and second resistor voltage divider modules can also limit the loop current.
[0008] Furthermore, the data acquisition module includes a first acquisition module, a second acquisition module, a third acquisition module, and a fourth acquisition module. The first acquisition module is connected in series with the first resistor voltage divider module. The second acquisition module is installed at the output terminal of the first resistor voltage divider module. The third acquisition module is installed at the output terminal of the second resistor voltage divider module. The two ends of the fourth acquisition module are respectively connected to the two ends of the through-hole screw.
[0009] When this device is running, firstly, the first acquisition module detects the presence of a current signal. If no current signal is detected, it indicates that there is no short circuit between the monitored through-bolt and the corresponding positioning rib. If a short circuit is detected, it indicates that there is a short circuit between the through-bolt and the corresponding positioning rib. Secondly, the number of short circuits is determined, the first acquisition module is turned off, and the second and fourth acquisition modules are turned on. The voltage value U1 of the entire first resistor voltage divider module can be calculated from the voltage value acquired by the second acquisition module. The distance l from the short circuit point on the through-bolt to one end of the through-bolt can be estimated from the voltage value acquired by the fourth acquisition module. Then, the third acquisition module is turned on, and together with the voltage values acquired by the fourth acquisition module, the distance l' from the short circuit point on the through-bolt to the other end of the through-bolt can be estimated. The length of the through-bolt is L. If l + l' = L, it indicates that there is one short circuit on the monitored through-bolt. If l + l' ≠ L, it indicates that there are multiple short circuits on the monitored through-bolt.
[0010] Furthermore, the data acquisition module also includes several infrared temperature sensors. The hydro-generator includes a generator housing, and the several infrared temperature sensors are evenly installed on the generator housing. The detection ends of the several infrared temperature sensors are linearly distributed and parallel to the positioning ribs.
[0011] The detection ends of multiple infrared temperature sensors are set parallel to each other at equal intervals with the positioning ribs. When there is a short circuit between the through screw and the opposite positioning rib, the temperature on the positioning rib corresponding to the short circuit will rise. By turning off the second, third and fourth acquisition modules and turning on the infrared temperature sensors, the number of short circuits can be determined.
[0012] Furthermore, the hydro-generator also includes a magnetically shielded housing mounted on the outer casing, and several of the infrared temperature sensors are installed inside the magnetically shielded housing. The magnetically shielded housing prevents external factors from interfering with the temperature monitoring of the infrared temperature sensors.
[0013] Furthermore, the connection point between the data acquisition module and the through-hole screw is provided with a first connection end. The first connection end includes a first nut, a Z-shaped washer, and a second nut sequentially sleeved on the through-hole screw. A first screw hole is formed on the side wall of the second nut, and a first screw is installed in the first screw hole. The first screw is connected to the data acquisition module. The electrical quantity on the through-hole screw is guided to the data acquisition module through the first screw for easy monitoring.
[0014] Furthermore, the first screw hole is a through hole, and the first screw is installed in the first screw hole and contacts the through-bolt. By having the first screw contact the through-bolt, the accuracy of electrical transmission is improved and errors are reduced.
[0015] Furthermore, a third nut is mounted on the first screw for fastening the connection end of the data acquisition module. This facilitates fixing and disassembling the connection end of the data acquisition module.
[0016] Furthermore, the connection point between the data acquisition module and the positioning rib is provided with a second connection end. The second connection end includes a fourth nut sleeved on the positioning rib. A second screw hole is formed on the side wall of the fourth nut, and a second screw is installed in the second screw hole. The second screw is connected to the data acquisition module. The electrical quantity on the through-bolt is guided to the data acquisition module through the second screw for easy monitoring.
[0017] Furthermore, the second screw hole is a through hole, and the second screw is installed inside the second screw hole and contacts the positioning rib. A fifth nut for fastening the connection end of the data acquisition module is installed on the second screw. By having the second screw contact the through screw, the transmission accuracy of electrical quantities is improved and errors are reduced. The fifth nut facilitates fixing and disassembling the connection end of the data acquisition module.
[0018] One or more technical solutions provided by this utility model have at least the following technical effects or advantages:
[0019] (1) This utility model collects the current and voltage values of the first resistor voltage divider module and the second resistor voltage divider module in real time through the data acquisition module, and judges in real time whether there is a short circuit between the through-core screw and the positioning rib. It can promptly report the short circuit between the through-core screw and the opposite positioning rib inside the hydro generator to the staff, so that the staff can handle the fault in time.
[0020] (2) Based on the voltage value of the through screw and the measured temperature of the corresponding positioning rib, determine the number and location of the short circuit points of the through screw;
[0021] (3) This utility model does not affect the structural safety of the bulb-type hydro turbine generator, and can ensure good electrical connection and reliable mechanical fixation between the through-bolt and the lead wire of the data acquisition module, and between the positioning rib and the lead wire of the data acquisition module, thus providing an application basis for realizing online monitoring of short circuit faults of the through-bolt-positioning rib. Attached Figure Description
[0022] The accompanying drawings, which are provided to further illustrate the embodiments of the present invention and constitute a part of the present invention, do not constitute a limitation thereof.
[0023] Figure 1 This is a cross-sectional view of the internal structure of the fault monitoring device in this utility model;
[0024] Figure 2 This is a schematic diagram of the installation structure of the first resistor voltage divider module in this utility model;
[0025] Figure 3 This is a schematic diagram of the first connecting end structure in this utility model;
[0026] Figure 4 This is a schematic diagram of the second connecting end structure in this utility model;
[0027] Among them, 1-through screw, 2-positioning rib, 3-first resistor voltage divider module, 4-second resistor voltage divider module, 501-first acquisition module, 502-second acquisition module, 503-third acquisition module, 504-fourth acquisition module, 505-infrared temperature sensor, 6-generator housing, 7-magnetic shielding housing, 8-first connecting end, 801-first nut, 802-Z-type washer, 803-second nut, 804-first screw, 805-third nut, 9-second connecting end, 901-fourth nut, 902-second screw, 903-fifth nut. Detailed Implementation
[0028] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of this utility model and the features within them can be combined with each other.
[0029] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.
[0030] Example 1
[0031] This embodiment provides a fault monitoring device for the through-screw of a bulb-type hydro turbine generator, such as... Figures 1-4 As shown, the device includes a hydro-generator, a through-hole screw 1 and a positioning rib 2 installed inside the hydro-generator, a first resistance voltage divider module 3, a second resistance voltage divider module 4, and several data acquisition modules for collecting data. The first resistance voltage divider module 3 is connected to one end of the through-hole screw 1 and one end of the positioning rib 2, and the second resistance voltage divider module 4 is connected to the other end of the through-hole screw 1 and the other end of the positioning rib 2.
[0032] The through-hole screw 1 and the positioning rib 2 are corresponding to each other. The first voltage divider module 3 and the second voltage divider module 4 each include at least two resistors. The first voltage divider module 3 includes two leads, which are respectively connected to one end of the through-hole screw 1 and one end of the positioning rib 2. The one end of the through-hole screw 1 and the one end of the positioning rib 2 are located on the same side of the hydro-generator. The second voltage divider module 4 also includes two leads, which are respectively connected to the other end of the through-hole screw 1 and the other end of the positioning rib 2. The other end of the through-hole screw 1 and the other end of the positioning rib 2 are also located on the same side of the hydro-generator.
[0033] In a more preferred embodiment, the data acquisition module includes a first acquisition module 501, a second acquisition module 502, a third acquisition module 503, and a fourth acquisition module 504. The first acquisition module 501 is connected in series with the first resistor voltage divider module 3. The second acquisition module 502 is installed at the output terminal of the first resistor voltage divider module 3. The third acquisition module 503 is installed at the output terminal of the second resistor voltage divider module 4. The two ends of the fourth acquisition module 504 are respectively connected to the two ends of the through-hole screw 1.
[0034] The first acquisition module 501 is used to acquire current values, the second acquisition module 502 is used to measure the voltage across one of the resistors in the first voltage divider module 3, the third acquisition module 503 is used to measure the voltage across one of the resistors in the second voltage divider module 4, and the fourth acquisition module 504 is used to measure the voltage across the through-core screw 1.
[0035] In this embodiment, the first resistor voltage divider module 3 and the second resistor voltage divider module 4 preferably have the same structure, both including two resistors R1 = 100Ω and R2 = 10000Ω. The second acquisition module 502 and the third acquisition module 503 respectively acquire the voltage across R1 in the first resistor voltage divider module 3 and the second resistor voltage divider module 4. Taking the first resistor voltage divider module 3 as an example...
[0036]
[0037] l = L U1 / U3;
[0038] l'=L U1 / U4;
[0039] Wherein, U1 is the voltage value of the two sections of the first resistor voltage divider module, U2 is the voltage value collected by the data module 2, l is the distance from the short circuit point on the through screw 1 to the end of the through screw 1 near the first resistor voltage divider module 3, L is the length of the through screw, U3 is the voltage value collected by the data acquisition module 3, and l' is the distance from the short circuit point on the through screw 1 to the end of the through screw 1 near the second resistor voltage divider module 4;
[0040] It can be concluded that if l+l'=L, it indicates that there is a short circuit point on the monitored through-bolt; if l+l'≠L, it indicates that there are multiple short circuit points on the monitored through-bolt.
[0041] In a more preferred embodiment, the data acquisition module further includes a plurality of infrared temperature sensors 505, and the hydro-generator includes a generator housing 6, wherein the plurality of infrared temperature sensors 505 are evenly mounted on the generator housing 6.
[0042] The number of infrared temperature sensors 505 is determined according to the length of the positioning rib 2. Preferably, the device also includes a control center, such as a microcontroller or PLC, and the data acquisition module and the infrared temperature sensors 505 are both connected to the control center.
[0043] In a more preferred embodiment, the detection ends of the plurality of infrared temperature sensors 505 are arranged in a straight line and are parallel to the positioning rib 2.
[0044] Regarding the infrared temperature sensor, due to a short circuit fault between the through-hole screw 1 and the positioning rib 2, the temperature at the short circuit point of the positioning rib 2 rises, emitting infrared rays of a specific wavelength. After these infrared rays are incident on the optical and photoelectric detection parts of the temperature measuring device, they are converted into electrical signals for output. The pulse height of the electrical signals generated by infrared rays of different wavelengths varies. After amplification and filtering by the signal amplification and processing unit to improve the signal amplitude and enhance the signal-to-noise ratio, the signal acquisition and processing unit integrates and shapes the pulse signal to form a specific form of infrared spectrum, which is then converted into a digital signal and transmitted to the host computer via a remote transmission method.
[0045] In a more preferred embodiment, the hydro-generator further includes a magnetically shielded housing 7 mounted on the outer casing, and a plurality of the infrared temperature sensors 505 are installed inside the magnetically shielded housing 7. The magnetically shielded housing 7 is a detachable housing, bolted to the generator housing 6, and has pre-drilled infrared transmission holes and cable through holes.
[0046] Example 2
[0047] Based on Embodiment 1, the connection point between the data acquisition module and the through-hole screw 1 is provided with a first connection end 8. The first connection end 8 includes a first nut 801, a Z-shaped washer 802 and a second nut 803 sequentially sleeved on the through-hole screw 1. A first screw hole is opened on the side wall of the second nut 803, and a first screw 804 is installed in the first screw hole. The first screw 804 is connected to the data acquisition module.
[0048] In a more preferred embodiment, the first screw hole is a through hole, and the first screw 804 is installed in the first screw hole and contacts the through screw 1.
[0049] In a more preferred embodiment, a third nut 805 for fastening the connection end of the data acquisition module is mounted on the first screw 804. The length of the first screw 804 is greater than the sum of the length of the first screw hole and the length of the third nut 805.
[0050] In a more preferred embodiment, the connection point between the data acquisition module and the positioning rib 2 is provided with a second connection end 9. The second connection end 9 includes a fourth nut 901 sleeved on the positioning rib 2. A second screw hole is opened on the side wall of the fourth nut 901. A second screw 902 is installed in the second screw hole and is connected to the data acquisition module.
[0051] In a more preferred embodiment, the second screw hole is a through hole, the second screw 902 is installed in the second screw hole and contacts the positioning rib 2, and a fifth nut 903 for fastening the connection end of the data acquisition module is installed on the second screw 902.
[0052] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.
[0053] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A bulb-type axial-flow hydro-generator through-core screw fault monitoring device, comprising a hydro-generator, characterized in that, It also includes a through-hole screw (1) and a positioning rib (2) installed in the hydro generator, as well as a first resistance voltage divider module (3), a second resistance voltage divider module (4) and a number of data acquisition modules for collecting data. The first resistance voltage divider module (3) is connected to one end of the through-hole screw (1) and one end of the positioning rib (2), and the second resistance voltage divider module (4) is connected to the other end of the through-hole screw (1) and the other end of the positioning rib (2).
2. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 1, characterized in that, The data acquisition module includes a first acquisition module (501), a second acquisition module (502), a third acquisition module (503), and a fourth acquisition module (504). The first acquisition module (501) is connected in series with the first resistor voltage divider module (3). The second acquisition module (502) is installed at the output end of the first resistor voltage divider module (3). The third acquisition module (503) is installed at the output end of the second resistor voltage divider module (4). The two ends of the fourth acquisition module (504) are respectively connected to the two ends of the through-hole screw (1).
3. The bulb-type axial-flow turbine generator through-screw fault monitoring device according to claim 1, characterized in that, The data acquisition module also includes several infrared temperature sensors (505), and the hydro generator includes a generator housing (6), with several infrared temperature sensors (505) evenly installed on the generator housing (6).
4. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 3, characterized in that, The detection ends of several infrared temperature sensors (505) are arranged in a straight line and are parallel to the positioning rib (2).
5. The bulb-type axial-flow turbine generator through-screw fault monitoring device according to claim 3, characterized in that, The hydro-generator also includes a magnetic shielding shell (7) installed on the outer shell, and several infrared temperature sensors (505) are installed inside the magnetic shielding shell (7).
6. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 1, characterized in that, The connection point between the data acquisition module and the through-hole screw (1) is provided with a first connection end (8). The first connection end (8) includes a first nut (801), a Z-shaped washer (802), and a second nut (803) sequentially sleeved on the through-hole screw (1). A first screw hole is provided on the side wall of the second nut (803). A first screw (804) is installed in the first screw hole. The first screw (804) is connected to the data acquisition module.
7. The bulb-type axial-flow turbine generator through-screw fault monitoring device according to claim 6, characterized in that, The first screw hole is a through hole, and the first screw (804) is installed in the first screw hole and contacts the through screw (1).
8. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 6, characterized in that, A third nut (805) for fastening the connection end of the data acquisition module is installed on the first screw (804).
9. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 1, characterized in that, The connection point between the data acquisition module and the positioning rib (2) is provided with a second connection end (9). The second connection end (9) includes a fourth nut (901) sleeved on the positioning rib (2). A second screw hole is opened on the side wall of the fourth nut (901). A second screw (902) is installed in the second screw hole. The second screw (902) is connected to the data acquisition module.
10. The bulb-type axial-flow turbine generator through-core screw fault monitoring device according to claim 9, characterized in that, The second screw hole is a through hole, the second screw (902) is installed in the second screw hole and contacts the positioning rib (2), and a fifth nut (903) for fastening the connection end of the data acquisition module is installed on the second screw (902).