A kind of carbon brush ignition monitoring device of hydroelectric generator

Abstract

The utility model discloses a kind of water turbine generator carbon brush ignition monitoring devices, including current collector ring, carbon brush, brush grip and support, carbon brush is contacted with current collector ring under the fixation of brush grip and support, receiving antenna of receiving electromagnetic signal is provided on the support, signal receiving end of receiving antenna is directly opposite carbon brush and current collector ring contact position, receiving antenna is electrically connected with controller 10.By monitoring electromagnetic signal generated when carbon brush ignites to monitor the ignition phenomenon of carbon brush.Avoid the multiple influencing factors that may exist when data is abnormal when temperature, current, wear and optical detection carbon brush and current collector ring ignition phenomenon, so as to cause unable to accurately determine whether there is ignition phenomenon generated;By monitoring the electromagnetic signal directly generated by carbon brush ignition phenomenon, electromagnetic signal is under the influence of space factors, obvious characteristics, can directly determine whether there is carbon brush ignition occurs.

Description

Technical Field

[0001] This utility model relates to the field of monitoring technology for the current collection and excitation system of hydro generators, and in particular to a monitoring device for carbon brush arcing of hydro generators. Background Technology

[0002] The carbon brush and slip ring assembly is a crucial component of a hydro-generator unit. The sliding contact of the slip ring and slip ring guides the excitation current into the rotor windings, creating an excitation magnetic field and establishing electrical continuity between stationary and rotating components. During unit operation, the carbon brush carries a large current, and due to factors such as insufficient smoothness of the slip ring surface and poor contact between the carbon brush and slip ring, sparking faults are prone to occur. Carbon brush sparking poses a serious threat to the safe operation of the unit and can even lead to short circuits in the excitation system, resulting in significant safety accidents and property damage.

[0003] Currently, monitoring of slip ring carbon brush systems generally focuses on temperature, current, and carbon brush wear. Sensors are placed on the carbon brush and brush holder to monitor temperature, current, and wear. However, judging the carbon brush's operating status through indirect parameter monitoring makes it difficult to directly determine whether sparking or discharge occurs during unit operation. Another approach is to use optical detectors to monitor discharge phenomena during carbon brush sparking. However, the internal lighting of the unit typically interferes with the detectors, reducing the accuracy of the monitoring results. Furthermore, the slip ring carbon brush system has a complex structure, and optical detectors can generally only be placed near the carbon brush support, resulting in a small monitoring area and requiring a large number of probes for comprehensive monitoring of carbon brush sparking. The limited space within the slip ring enclosure, coupled with numerous devices, makes comprehensive optical monitoring difficult. Utility Model Content

[0004] This invention aims to provide a carbon brush sparking monitoring device for hydro-generators. It monitors the sparking phenomenon by detecting the electromagnetic signals generated during carbon brush sparking, avoiding the inaccurate judgment caused by multiple influencing factors such as temperature, current, wear, and data anomalies when optically detecting sparking between the carbon brush and slip ring. By monitoring the electromagnetic signals directly generated by carbon brush sparking, which are significantly affected by spatial factors, the device can directly determine whether carbon brush sparking has occurred.

[0005] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows: A carbon brush ignition monitoring device for a hydro-generator includes a slip ring, a carbon brush, a brush holder, and a bracket. The carbon brush is in contact with the slip ring while being fixed by the brush holder and the bracket. A receiving antenna for receiving electromagnetic signals is provided on the bracket. The signal receiving end of the receiving antenna is directly facing the contact position between the carbon brush and the slip ring. The receiving antenna is electrically connected to a controller.

[0006] The carbon brush includes an upper carbon brush and a lower carbon brush, which are fixed by brush holders and in contact with the top positive electrode and bottom negative electrode of the current collector ring, respectively. The receiving antenna is an ultra-high frequency planar butterfly antenna; The height of the receiving antenna is directly opposite the midpoint between the upper and lower carbon brushes.

[0007] The plane of the ultra-high frequency planar butterfly antenna faces the carbon brush and collector ring side; The ultra-high frequency planar butterfly antenna has a metal backplate on its back. The metal backplate can shield electromagnetic interference from the rear, concentrate the monitoring range to both sides and the front of the planar antenna, and monitor the carbon brush discharge signal while shielding signals from other locations. The backplate is fixedly attached to the base welded to the brush holder bracket.

[0008] The ultra-high frequency planar butterfly antenna is connected to the bracket via a base, and the metal backplate is fixedly connected to the base, which in turn is fixedly connected to the bracket.

[0009] Multiple receiving antennas are distributed along the circumference of the collector ring. This enables comprehensive monitoring of the carbon brush system of the turbine generator's collector ring, allowing for complete monitoring and location analysis of all carbon brush sparking phenomena.

[0010] The controller is an embedded ultra-high frequency processing device; it can extract the frequency and amplitude of electromagnetic pulse signals.

[0011] The beneficial effects of this utility model are: 1. In this invention, the slip ring rotates with the rotating assembly, and the carbon brush slides into contact with it, enabling current conduction. The slip ring and carbon brush have dynamic electrical contact, and a very high induced voltage is generated at the contact point. When the induced voltage exceeds the breakdown strength, discharge occurs, resulting in an arcing fault. Simultaneously, a high-frequency, high-voltage pulse is induced, radiating electromagnetic wave signals outwards. Experiments have shown that the frequency of this electromagnetic wave signal is mainly distributed between 100MHz and 300MHz. By receiving signals in this frequency band using a receiving antenna and extracting characteristics such as the frequency amplitude of the electromagnetic pulse signal, it is determined whether carbon brush arcing has occurred.

[0012] 2. This invention employs an ultra-high frequency planar butterfly antenna. The planar butterfly antenna has circumferential directivity. The plane of the planar butterfly antenna should be directly facing the carbon brush and the collector ring side, and the antenna height should be directly aligned with the middle position of the upper and lower carbon brush rings. This ensures that the carbon brush sparking signal meets its directional characteristics, enabling the detection of sparking signals over a wide circumferential range.

[0013] 3. In this utility model, multiple antennas are arranged in a circular array to achieve comprehensive monitoring of the carbon brush system of the turbine generator collector ring, thus satisfying the need for comprehensive monitoring and location analysis of all carbon brush sparking phenomena.

[0014] 4. In this invention, the antenna uses a metal backplate, which can shield electromagnetic interference from the rear, concentrating the monitoring range to both sides and the front of the planar antenna, monitoring the carbon brush discharge signal while shielding signals from other locations. The backplate is fixedly attached to the base welded to the brush holder bracket. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the hydro-generator carbon brush ignition monitoring device of this utility model.

[0016] Figure 2 This is a schematic diagram of the directional plane of the ultra-high frequency planar butterfly antenna of this utility model.

[0017] Figure 3 This is a three-dimensional directional schematic diagram of the ultra-high frequency planar butterfly antenna of this utility model.

[0018] Figure 4 This is a schematic diagram of the structure of the ultra-high frequency planar butterfly antenna of this utility model.

[0019] Figure 5 This is a schematic diagram showing the distribution of the receiving antenna of this utility model.

[0020] Figure 6 This is a schematic diagram of the controller installation of this utility model.

[0021] Figure 7 This is a wiring diagram of the receiving antenna and controller of this utility model.

[0022] The components include: 1. Collector ring; 2. Carbon brush; 3. Brush holder; 4. Bracket; 5. Upper carbon brush; 6. Lower carbon brush; 7. Metal backplate; 8. Base; 9. Receiving antenna; 10. Controller; 11. Outer casing; 12. Radio frequency cable. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0024] This invention proposes an ultra-high frequency antenna arrangement for carbon brush ignition, which monitors the ignition phenomenon of carbon brushes by monitoring the electromagnetic signals generated when carbon brushes ignite, thereby achieving comprehensive monitoring of the ignition phenomenon of all carbon brushes in a hydro-generator.

[0025] Example: This embodiment provides a hydro-generator carbon brush spark monitoring device, including a slip ring 1, a carbon brush 2, a brush holder 3, and a bracket 4. The carbon brush 2 is in contact with the slip ring 1 under the fixation of the brush holder 3 and the bracket 4. The bracket 4 is provided with a receiving antenna 9 for receiving electromagnetic signals. The signal receiving end of the receiving antenna 9 is directly facing the contact position between the carbon brush 2 and the slip ring 1. The receiving antenna 9 is electrically connected to a controller 10.

[0026] In this embodiment, the slip ring 1 rotates with the rotating components of the turbine generator unit, and the carbon brush 2 slides into contact with it, enabling current conduction. The slip ring 1 and carbon brush 2 have dynamic electrical contact, and a very high induced voltage is generated at the contact point. When the induced voltage exceeds the breakdown strength, a discharge occurs, resulting in an arcing fault. Simultaneously, a high-frequency, high-voltage pulse is induced, radiating electromagnetic wave signals outwards. Experiments have shown that the frequency of this electromagnetic wave signal is mainly distributed between 100MHz and 300MHz. Signals in this frequency band are received using the receiving antenna 9, and by extracting characteristics such as the frequency amplitude of the electromagnetic pulse signal, it is determined whether arcing of the carbon brush 2 has occurred.

[0027] In an optional embodiment of this utility model, the carbon brush 2 includes an upper carbon brush 5 and a lower carbon brush 6, which are fixed by a brush holder 3 and in contact with the top positive electrode and bottom negative electrode of the current collector ring 1, respectively.

[0028] In this invention, the upper ring carbon brush 2 and the lower ring carbon brush 2 are in contact with the positive and negative terminals of the collector ring 1, respectively, to realize the inflow and outflow of the generator excitation current.

[0029] In an optional embodiment of this invention, the receiving antenna 9 is an ultra-high frequency planar butterfly antenna, and the height of the receiving antenna 9 is directly opposite the midpoint between the upper carbon brush 5 and the lower carbon brush 6. The plane of the ultra-high frequency planar butterfly antenna faces the side of the carbon brush 2 and the collector ring 1.

[0030] In this invention, an ultra-high frequency antenna is used to receive the electromagnetic wave signal generated during ignition. The ultra-high frequency planar butterfly antenna has circumferential directivity, and its directivity is as follows: Figure 2 and Figure 3 As shown, this indicates that the antenna is more sensitive to circumferential signals. The monitoring range is concentrated on both sides and in front of the planar antenna, and it is installed in the middle of the upper and lower ring carbon brushes so that the arcing signal of carbon brush 2 meets its directional characteristics and covers the entire discharge signal of carbon brush 2; thus realizing the detection of arcing signals over a large circumferential range.

[0031] In optional embodiments of this utility model, such as Figure 4 As shown, the UHF planar butterfly antenna has a metal backplate 7 (such as carbon steel, aluminum alloy, or other ferromagnetic materials) on its back. The UHF planar butterfly antenna is connected to the bracket 4 via a base 8, the metal backplate 7 is fixedly connected to the base 8, and the base 8 is fixedly connected to the bracket 4.

[0032] In this invention, the metal backplate 7 can shield electromagnetic interference from the rear, concentrating the monitoring range to both sides and the front of the planar antenna, covering the discharge signal of the carbon brush 2 while shielding signals from other locations. The backplate is fixedly attached to the base 8 welded to the brush holder bracket 4.

[0033] In optional embodiments of this utility model, such as Figure 5 As shown, the collector ring 1 has four receiving antennas 9 distributed around its circumference.

[0034] In this invention, multiple antennas are arranged in a circular array (the distance between each antenna on the circumference of the antenna array can be controlled within a certain range). 3m Within the specified range, comprehensive monitoring of the collector ring 1 and carbon brush 2 system of the hydro-generator is achieved, satisfying the need for comprehensive monitoring and location analysis of all carbon brush 2 sparking phenomena.

[0035] In an optional embodiment of this utility model, the controller 10 is an embedded ultra-high frequency processing device; it can extract the frequency and amplitude of electromagnetic pulse signals.

[0036] In this utility model, such as Figure 6 As shown, the controller 10 is installed on the inner wall of the outer casing 11 of the hydro-generator, as... Figure 7 As shown, the four receiving antennas 9 are connected to the controller 10 via radio frequency lines 12.

[0037] This invention emphasizes utilizing the ultra-high frequency electromagnetic wave signal radiated by the carbon brush 2 during ignition. Based on its frequency characteristics, an ultra-high frequency planar antenna is employed. Leveraging the directivity of the planar antenna, and by shielding the signal behind it, the monitoring range is concentrated. The antenna is positioned vertically between the upper and lower rings of carbon brush 2, and its circumferential arrangement achieves comprehensive monitoring of the carbon brush 2 ignition signal. The amplitude and frequency of the monitored signal are extracted to determine whether ignition has occurred.

[0038] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A carbon brush spark monitoring device for a hydro-generator, comprising a slip ring (1), a carbon brush (2), a brush holder (3), and a bracket (4), wherein the carbon brush (2) is in contact with the slip ring (1) under the fixation of the brush holder (3) and the bracket (4), characterized in that: The bracket (4) is provided with a receiving antenna (9) for receiving electromagnetic signals. The signal receiving end of the receiving antenna (9) is directly facing the contact position between the carbon brush (2) and the collector ring (1). The receiving antenna (9) is electrically connected to a controller (10).

2. The hydro-generator carbon brush spark monitoring device according to claim 1, characterized in that: The carbon brush (2) includes an upper carbon brush (5) and a lower carbon brush (6), which are fixed by a brush holder (3) and in contact with the top positive electrode and bottom negative electrode of the collector ring (1).

3. The hydro-generator carbon brush spark monitoring device according to claim 2, characterized in that: The height of the receiving antenna (9) is directly opposite the middle position of the upper carbon brush (5) and the lower carbon brush (6).

4. The hydro-generator carbon brush spark monitoring device according to claim 1, characterized in that: The receiving antenna (9) is an ultra-high frequency planar butterfly antenna.

5. The hydro-generator carbon brush spark monitoring device according to claim 4, characterized in that: The plane of the ultra-high frequency planar butterfly antenna faces the carbon brush (2) and the collector ring (1).

6. The hydro-generator carbon brush spark monitoring device according to claim 4, characterized in that: The back of the ultra-high frequency planar butterfly antenna is provided with a metal backplate (7).

7. The hydro-generator carbon brush spark monitoring device according to claim 6, characterized in that: The ultra-high frequency planar butterfly antenna is connected to the bracket (4) via the base (8), the metal back plate (7) is fixedly connected to the base (8), and the base (8) is fixedly connected to the bracket (4).

8. The hydro-generator carbon brush spark monitoring device according to claim 1, characterized in that: Multiple receiving antennas (9) are distributed along the circumference of the collector ring (1).

9. The hydro-generator carbon brush spark monitoring device according to claim 1, characterized in that: The controller (10) is an embedded ultra-high frequency processing device.

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