System for measuring generator shaft voltage and shaft current

Abstract

A system for measuring generator shaft voltage and shaft current, which system relates to the technical field of power systems. The system comprises a mounting component (100), which is used for mounting grounding carbon brushes (200) on a rotating shaft of a generator at the end that is close to an exciter and at the end that is close to a steam turbine, wherein the grounding carbon brushes (200) include a first grounding carbon brush (201) and a second grounding carbon brush (202) which are located at the steam turbine end of the generator, and a third grounding carbon brush (203) at the exciter end thereof; and by means of monitoring shaft voltage and shaft current in real time, a processing module (303) calculates key parameters and performs real-time analysis and spectrum analysis. When a monitored value exceeds a threshold value, the system immediately issues an alarm, thereby effectively realizing the real-time determination of the operating state of a generator and fault early warning. Moreover, the system has the functions of storing and querying historical data, by means of which operators can evaluate the insulation performance of a generator shaft and predict potential problems, and thus prevent insulation accidents caused by an overly high shaft current, thereby prolonging the service life of devices, and ensuring the continuity and stability of a power production process.

Description

System for measuring generator shaft voltage and shaft current TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, and particularly relates to a system for measuring generator shaft voltage and shaft current. BACKGROUND

[0002] As the core equipment of a power system, a turbo-generator plays a vital role in the power generation process. Shaft voltage is the voltage between the shaft and the bearing or the voltage between the two bearing ends of the generator during operation. Under normal circumstances, when the shaft voltage is low, the lubricating oil film can maintain good insulation performance to prevent the generation of shaft current. However, when the shaft voltage rises to a certain value due to various factors, the oil film will be punctured, forming a shaft current loop, i.e. the generator shaft-shaft neck-bearing bush-bearing support-generator base. The generation of shaft current will cause the lubricating oil film to lose stability, and the oil quality to deteriorate. Moreover, when the current passes through the metal contact point of the bearing, high temperature will be generated in a short time due to the small contact area and high current density, causing the local melting of the bearing alloy, and further forming pits on the inner surface of the bearing, accelerating the wear of the bearing, and even causing the bearing bush to burn out, forcing the generator to stop.

[0003] The level of shaft voltage is affected by factors such as the capacity of the generator set, air gap magnetic flux, structural asymmetry, magnetic field harmonic components, core saturation degree, and stator unevenness. Generally, the larger the capacity of the generator set, the higher the peak value of the shaft voltage, and the shaft voltage waveform contains complex harmonic components, especially for generator sets using static controllable rectification excitation, the pulse component in the shaft voltage waveform is high, which is particularly unfavorable to the oil film insulation.

[0004] In order to timely discover and handle the shaft current problem, the current conventional method is to periodically measure the shaft voltage. The specific method is to use the voltage range of a multimeter, an insulating rod with a 300mm insulating handle, and a carbon brush to measure. During the measurement process, one person is responsible for holding the multimeter and grounding the black pen of the multimeter, and the other person wears insulating gloves to operate the insulating rod and contacts the generator shaft with the carbon brush. By comparing the shaft voltage U1 between the steam excitation end of the generator and the shaft voltage U2 between the excitation end and the ground, the shaft insulation condition is determined: if U1 is equal to U2, it indicates that the insulation is good; if U1 is greater than U2 and exceeds U2 by 10%, it means that there is a problem with the bearing insulation, and the insulation pad needs to be handled and the surface oil needs to be cleaned; if U1 is less than U2, it may be that the carbon brush contacting the steam end of the shaft is not good or the measurement is not accurate, and the carbon brush needs to be cleaned and then measured again. For the measurement of shaft current, the current range of the multimeter is also used in cooperation with the insulating rod and the carbon brush. Under normal circumstances, the shaft current should be lower than the standard value of 0.5A. If the shaft current exceeds the standard value, it may cause overheating of the generator, damage to the wire insulation, and other problems, which will have a negative impact on the entire generator system. In actual operation, since the generator is a rotating equipment, at least two people are required to cooperate in this type of detection work, and safety precautions need to be taken at all times.

[0005] SUMMARY

[0006] In view of the above-mentioned problems existing in the prior art generator shaft voltage and current measurement system, the present application is proposed.

[0007] Therefore, the purpose of the present application is to provide a generator shaft voltage and current measurement system, which aims to solve the problems existing in the traditional shaft voltage and current measurement, and provide real-time, continuous and accurate monitoring data to improve the safety and reliability of the generator operation.

[0008] To solve the above technical problems, the present application provides the following technical solutions: including installation components for installing grounding carbon brushes near the exciter end and the turbine end of the generator shaft, which includes a first grounding carbon brush at the turbine end of the generator, a second grounding carbon brush, and a third grounding carbon brush at the exciter end of the generator;

[0009] The monitoring components include a current transformer for monitoring and measuring the grounding current at the turbine end of the generator, which is installed on the line between the first grounding carbon brush down lead and the turbine grounding point; a voltage sensor for collecting the voltage between the exciter end and the turbine end, the voltage sensor is installed on the line between the second grounding carbon brush down lead and the third grounding carbon brush down lead; a processing module electrically connected to the current transformer and the voltage sensor, which is used for real-time analysis of the collected voltage and current signals, calculation of single peak value, average value, effective value and peak-to-peak value, and accurate discrimination and analysis, and at the same time, when the measured value of shaft voltage or shaft current exceeds the preset threshold, an alarm signal is sent.

[0010] As a preferred scheme of the generator shaft voltage and current measurement system, the processing module includes a real-time analysis unit for real-time analysis of the collected voltage and current signals, calculation of single peak value, average value, effective value and peak-to-peak value, and accurate discrimination and analysis through spectrum analysis technology and corresponding data model; an alarm unit for sending an alarm signal when the measured value of shaft voltage or shaft current exceeds the preset threshold; a historical data storage and query unit for storing the shaft voltage and current waveform historical data during the generator operation, and allowing to be called and queried at any time, which serves as the basis for judging whether the generator shaft insulation is good.

[0011] As a preferred scheme of the generator shaft voltage and current measurement system, the mounting component comprises two symmetrically arranged mounting plates, the two mounting plates are clamped around the rotating shaft of the generator, the inner wall of the mounting plate is provided with an extended rolling element which is in contact with the outer wall of the rotating shaft of the generator, the inner part of the mounting plate is further provided with a self-locking element which is used to lock the two mounting plates and push the rolling element outward, the side of the mounting plate is provided with a plurality of accommodating shells, a sliding mounting seat is arranged in each accommodating shell on the side wall of the mounting plate, and the grounding carbon brush is mounted on the mounting seat.

[0012] As a preferred scheme of the generator shaft voltage and current measurement system, the two mounting plates are connected by the self-locking element to form a complete ring, a first accommodating groove is formed at one end of each mounting plate, a latch is slidingly arranged in the first accommodating groove, a first spring is further arranged in the first accommodating groove, the first spring is used for resetting the latch, a lock hole is formed at the other end of the mounting plate, the latch is inserted into the lock hole, and the front end of the latch is provided in a trapezoidal shape.

[0013] As a preferred scheme of the generator shaft voltage and current measurement system, a second accommodating groove is formed at the position close to the two ends of the side wall of the mounting plate, the second accommodating groove is in communication with the first accommodating groove or the lock hole, respectively, and the rolling element is arranged in the second accommodating groove, the rolling element comprises a first frame, a second frame is slidingly arranged in the first frame, a second spring is further arranged in the first frame for pushing the second frame outward, a rolling wheel is arranged in the second frame, the inner end of the first frame is provided in a trapezoidal head, and the latch extrudes the trapezoidal head.

[0014] As a preferred scheme of the generator shaft voltage and current measurement system, a plurality of missing grooves are formed on the mounting plate, the mounting seat slides along the missing groove, the mounting seat comprises a sliding plate, a sliding groove is formed on the sliding plate, a sliding seat is slidingly arranged in the sliding groove, a third spring is further arranged in the sliding groove for pushing the sliding seat to move, and the grounding carbon brush is detachably mounted on the sliding seat.

[0015] As a preferred scheme of the generator shaft voltage and current measurement system, the four grounding carbon brushes are divided into two groups in opposite pairs, two grounding carbon brushes in the same group are used simultaneously, and the accommodating shell and the mounting seat correspond to the grounding carbon brush one by one.

[0016] As a preferred scheme of the generator shaft voltage and current measurement system, the bottom of each slide plate is provided with a mounting shaft, two adjacent mounting shafts are connected in series through a connecting plate, four connecting plates form a parallelogram frame, and an electric screw is arranged in one of the missing slots and screwed to the corresponding mounting shaft.

[0017] As a preferred scheme of the generator shaft voltage and current measurement system, the upper end surface of each containing shell is provided with a notch, the side surface is provided with a first through slot, and a power connection ring is clamped in the first through slot, and the side surface of the grounding carbon brush is provided with a second through slot, and the second through slot is clamped in the power connection ring.

[0018] As a preferred scheme of the generator shaft voltage and current measurement system, the power connection ring is divided into two types, which are the same type or two types corresponding to the four grounding carbon brushes, when the grounding carbon brushes are of the same type, two power connection rings are inserted to form a ring and are fixed with a down lead, and when the grounding carbon brushes are of two types, two power connection rings are respectively connected with a down lead.

[0019] The application has the advantages that: the shaft voltage and current are monitored in real time, the key parameters are calculated by the processing module, and real-time and spectral analysis are performed. When the monitoring value exceeds the threshold value, the system immediately issues an alarm, effectively realizing real-time judgment and fault warning of the generator running state. At the same time, the system has a historical data storage and query function, by which the staff can evaluate the insulation performance of the generator shaft, predict potential problems, prevent insulation accidents caused by high shaft current, thereby prolonging the service life of the equipment and ensuring the continuous and stable production process of electric power.

[0020] In the design of the installation part, a symmetrical double installation plate structure is adopted, which is quickly spliced and locked through a self-locking piece, ensures that the installation plate is fastened on the generator shaft, and reduces friction and wear during rotation. The electric screw controls the movement of the sliding seat, so that the grounding carbon brush is accurately installed in the containing shell, and the installation and replacement are convenient and efficient. The rolling piece inside the installation plate rolls with the generator shaft, ensuring good contact and effective monitoring of the shaft voltage and current. The parallelogram frame structure enables the four mounting seats to move synchronously, allowing two grounding carbon brushes in the same group to be installed or replaced at the same time, greatly improving the reliability and work efficiency of the system. In addition, the system has spare grounding carbon brushes, which can be quickly replaced through sliding adjustment when worn, simplifying maintenance work and improving overall operation safety. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0022] Fig. 1 is a layout diagram of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0023] Fig. 2 is a schematic diagram of the overall structure of the installation component of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0024] Fig. 3 is a schematic diagram of the overall structure of the installation component of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0025] Fig. 4 is a schematic diagram of the overall structure of the installation component of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0026] Fig. 5 is a schematic diagram of the assembled state of the installation component of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0027] Fig. 6 is a schematic diagram of the cross-sectional structure of the installation component of the system for measuring the shaft voltage and shaft current of a generator according to the present application.

[0028] Fig. 7 is an enlarged schematic diagram of the structure at A in Fig. 6.

[0029] In the drawings:

[0030] 100, installation component; 101, installation plate; 102, rolling element; 102a, second accommodating groove; 102b, first frame; 102c, second frame; 102d, second spring; 102e, roller; 102f, trapezoidal head; 103, self-locking element; 103a, first accommodating groove; 103b, bolt; 103c, first spring; 103d, lock hole; 104, accommodating shell; 104a, notch; 104b, first slot; 105, mounting seat; 105a, slot; 105b, sliding plate; 105c, sliding groove; 105d, sliding seat; 105e, third spring; 105f, connecting plate; 105g, electric screw; 105h, mounting shaft; 106, power connection ring;

[0031] 200, grounding carbon brush; 201, first grounding carbon brush; 202, second grounding carbon brush; 203, third grounding carbon brush; 204, second slot;

[0032] 300, monitoring component; 301, current transformer; 302, voltage sensor; 303, processing module. DETAILED DESCRIPTION

[0033] In order to make the above objectives, features and advantages of the present application more obvious and comprehensible, specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0034] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other ways that are not exactly as described in this description. It is understood that variations can be made in view of what is described and understood that it can be done without departing from the scope of the present application.

[0035] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0036] Thirdly, the present application is described in detail in conjunction with the schematic diagram. In the detailed description of the embodiments of the present application, the cross-sectional view of the device structure is partially enlarged without the general proportion for the convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the present application herein. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in actual manufacture.

[0037] Embodiment 1

[0038] Referring to FIG. 1, a first embodiment of the present application provides a system for measuring generator shaft voltage and shaft current, comprising a mounting component 100 for installing ground carbon brushes 200 on the shaft of the generator near the exciter end and the turbine end, respectively, wherein the ground carbon brushes 200 include a first ground carbon brush 201 at the turbine end of the generator, a second ground carbon brush 202, and a third ground carbon brush 203 at the exciter end of the generator; a monitoring component 300, comprising a current transformer 301 for monitoring and measuring the ground current at the turbine end of the generator, wherein the current transformer 301 is installed on the line between the downlead of the first ground carbon brush 201 and the grounding point of the turbine; a voltage sensor 302 for collecting the voltage between the exciter end and the turbine end, and the voltage between the exciter end and the ground, and the voltage between the turbine end and the ground, wherein the voltage sensor 302 is installed on the line between the downlead of the second ground carbon brush 202 and the downlead of the third ground carbon brush 203; a processing module 303 electrically connected to the current transformer 301 and the voltage sensor 302, wherein the processing module 303 is used for real-time analysis of the collected voltage and current signals, calculation of the single peak value, average value, effective value and peak-to-peak value, and accurate discrimination and analysis, and sending an alarm signal when the measured value of the shaft voltage or the shaft current exceeds the preset threshold value.

[0039] The processing module 303 includes a real-time analysis unit for real-time analysis of the collected voltage and current signals, calculation of single peak value, average value, effective value and peak-to-peak value, and accurate discrimination and analysis through spectrum analysis technology and corresponding data model; an alarm unit for issuing an alarm signal when the measured value of shaft voltage or shaft current exceeds the preset threshold; a historical data storage and query unit for storing the shaft voltage and shaft current waveform historical data during the operation of the generator and allowing to be called and queried at any time, thereby serving as a basis for judging whether the generator shaft insulation is good.

[0040] It should be noted that the installation component 100 is provided with the grounding carbon brush 200 at the exciter end and the turbine end of the generator shaft, including the first grounding carbon brush 201 and the second grounding carbon brush 202 at the turbine end and the third grounding carbon brush 203 at the exciter end, which are directly in contact with the generator shaft, sense the voltage difference between the two ends of the shaft, and detect the shaft current. This arrangement effectively avoids damage to the original insulation system of the generator, facilitates improvement of the existing generator, and improves the reliability of the monitoring data.

[0041] The monitoring component 300 includes current monitoring and voltage monitoring. The current monitoring uses the current transformer 301 installed on the line between the first grounding carbon brush 201 down lead and the turbine grounding point to capture and measure the grounding current of the turbine end of the generator in real time. It can not only accurately measure the key parameters of the shaft current (such as single peak value, average value, effective value and peak-to-peak value), but also sensitively track the transient change of the shaft current, greatly enhancing the accuracy and sensitivity of the shaft current monitoring. The voltage monitoring uses the voltage sensor 302 installed on the line between the second grounding carbon brush 202 and the third grounding carbon brush 203 down lead to collect and measure the voltage between the exciter end and the turbine end in real time.

[0042] The core processing module 303 of the system is closely connected with the current transformer 301 and the voltage sensor 302, and can perform real-time and in-depth analysis on the collected voltage and current signals. The module uses advanced spectrum analysis technology and related data models to ensure the high accuracy of data interpretation. The processing module 303 also integrates a real-time analysis unit, an alarm unit, and a historical data storage and query unit. The real-time analysis unit is responsible for real-time calculation and in-depth analysis of various indicators. The alarm unit will quickly send an alarm signal when the shaft voltage or shaft current exceeds the preset safety threshold, guiding the operation and maintenance personnel to respond in a timely manner. The historical data storage and query unit records the historical data of the shaft voltage and shaft current waveform during the operation of the generator. The staff can retrieve and query at any time as needed. These historical data provide an intuitive and scientific basis for evaluating the shaft insulation performance of the generator, and help to predict potential problems through historical data analysis, thereby effectively preventing and reducing the risk of generator failure caused by abnormal shaft voltage and shaft current.

[0043] In general, the new monitoring system provided by the present application solves many problems in traditional shaft voltage and shaft current measurement through multiple technical innovations and functional integration, and realizes all-around and three-dimensional real-time monitoring and intelligent analysis of the shaft voltage and shaft current of the generator. This system greatly improves the safety and reliability of the generator operation, effectively ensures the stability and continuity of the power production process, and demonstrates its significant practical value and creative contribution.

[0044] Embodiment 2

[0045] Referring to FIGS. 2-5, the second embodiment of the present application is different from the first embodiment in that the mounting component 100 includes two symmetrically arranged mounting plates 101, the two mounting plates 101 clamp the shaft of the generator inside, and the inner wall of the mounting plate 101 is provided with an extended rolling element 102 that fits the outer wall of the generator shaft. The inner part of the mounting plate 101 is also provided with a self-locking element 103 for locking the two mounting plates 101 and pushing the rolling element 102 outward. The side of the mounting plate 101 is provided with a plurality of accommodating shells 104, and a sliding mounting seat 105 is arranged in each accommodating shell 104 on the side wall of the mounting plate 101. The grounding carbon brush 200 is installed on the mounting seat 105.

[0046] In the embodiment, the two mounting plates 101 are spliced and locked to tightly sandwich the generator shaft, the self-locking members 103 at both ends of the two mounting plates 101 are inserted and locked to lock the two mounting plates 101 together to form a complete ring, the mounting plates 101 are firmly fixed on the generator shaft, and the rolling members 102 on the inner wall of the mounting plates 101 are extruded to fit the outer wall of the generator shaft when the self-locking members 103 are inserted and locked, so that the mounting plates 101 are fixed on the generator shaft and rotate freely, the rotating resistance is reduced, and the abrasion of the mounting plates 101 and the shaft caused by friction is reduced, then the grounding carbon brushes 200 are installed through the mounting seats 105 on the mounting plates 101, so that the grounding carbon brushes 200 are installed on the inner wall of the containing shell 104, and two of the grounding carbon brushes 200 always contact the outer wall of the generator shaft through sliding adjustment to monitor the shaft voltage or current in real time.

[0047] Further, considering that the grounding carbon brushes 200 will be greatly abraded during contact with the high-speed rotating generator shaft, an additional set of grounding carbon brushes 200 is reserved as a backup, when a set of carbon brushes is severely abraded, the new carbon brush can be quickly replaced through the sliding mounting seat 105 to ensure the continuous and stable operation of the monitoring system, which not only improves the reliability of the monitoring system, but also facilitates maintenance operation, and reflects the attention to details and thoughtful consideration for long-term use.

[0048] The remaining structure is the same as that of example 1.

[0049] Example 3

[0050] Referring to FIG. 2-7, for the third embodiment of the present application, the difference from the second embodiment is that two mounting plates 101 are formed into a complete ring by self-locking pieces 103, a first accommodating groove 103a is formed at one end of each mounting plate 101, a latch 103b is slidably arranged in the first accommodating groove 103a, a first spring 103c is further arranged in the first accommodating groove 103a for resetting the latch 103b, a lock hole 103d is formed at the other end of the mounting plate 101, the latch 103b is inserted into the lock hole 103d, and the front end of the latch 103b is arranged as a trapezoidal head. A second accommodating groove 102a is formed at the position of the side wall of the mounting plate 101 close to the two ends, the second accommodating groove 102a is respectively connected with the first accommodating groove 103a or the lock hole 103d, a rolling piece 102 is arranged in the second accommodating groove 102a, the rolling piece 102 includes a first frame 102b, a second frame 102c is slidably arranged in the first frame 102b, a second spring 102d is further arranged in the first frame 102b for pushing the second frame 102c to move outward, a roller 102e is arranged in the second frame 102c, the inner end of the first frame 102b is arranged as a trapezoidal head 102f, and the latch 103b presses the trapezoidal head 102f.

[0051] It should be noted that two self-locking pieces 103 are respectively arranged at the splicing positions of the two mounting plates 101 to realize multiple functions. First, through the locking mechanism of the self-locking piece 103, the two mounting plates 101 are effectively and stably fixed together, ensuring the stability of the overall structure. Secondly, the self-locking piece 103, while locking the mounting plate 101, skillfully completes the extrusion operation of the rolling pieces 102 at the two ends of the mounting plate 101, so that the rolling pieces 102 are tightly fitted on the outer wall of the generator shaft, thereby effectively reducing the shaking of the mounting component 100 on the generator shaft and greatly improving the stability and accuracy of the monitoring system. The same self-locking piece 103 can simultaneously act on the rolling pieces 102 at the two ends of the mounting plate 101 when it is inserted and locked into the two mounting plates 101, so that they are simultaneously extruded and locked in the appropriate position.

[0052] Wherein, in the second accommodating groove 102a of each mounting plate 101, a first frame 102b structure is designed to extend outward, when the bolt 103b is inserted and pushed, the first frame 102b is driven to move forward, and then the rolling member 102 is pushed out of the second accommodating groove 102a, so as to keep contact with the generator shaft. In order to further enhance flexibility and adaptability, the inside of the first frame 102b is further provided with a second frame 102c which can slide, and the rolling wheel 102e is installed on the second frame 102c. Through the cooperation of the second spring 102d, the second frame 102c can be self-adaptively adjusted according to the actual diameter or distance of the generator shaft, so as to ensure that the rolling member 102 can always properly fit on the surface of the shaft, so as to achieve ideal monitoring effect on generators of various specifications.

[0053] Specifically, when installing the mounting component 100 on the generator shaft, first, the two symmetrically designed mounting plates 101 are simultaneously moved towards the shaft center from the opposite sides of the generator shaft until the two mounting plates 101 are completely closed into a circular ring structure. When splicing, one end of each mounting plate 101 is provided with the bolt 103b of the self-locking member 103, and the bolt 103b can be smoothly inserted into the guide hole of the lock hole 103d of the other mounting plate 101 due to the trapezoidal shape of the front end of the bolt 103b. During the process of inserting the bolt 103b into the guide hole, the first spring 103c connected to the rear end of the bolt 103b will be deformed and stretched under the force due to the blocking of the guide hole. When the bolt 103b is gradually withdrawn to the deepest part of the first accommodating groove 103a, it cannot continue to move backward, so it will further move forward and insert its front end into the lock hole 103d.

[0054] Meanwhile, during the movement of the plug 103b backward, pressure is applied to the trapezoidal head 102f at the junction of the first accommodating groove 103a and the first accommodating groove 103a, thereby driving the trapezoidal head 102f in the second accommodating groove 102a and the first frame 102b to expand outward along the second accommodating groove 102a, which makes the second frame 102c inside the first frame 102b and the roller 102e also push outward, so that one rolling member 102 tightly fits the outer wall of the generator shaft. When the plug 103b is inserted into the lock hole 103d, the trapezoidal head 102f in the second accommodating groove 102a connected with the lock hole 103d on the other mounting plate 101 is also extruded, which drives the first frame 102b and the second frame 102c and the roller 102e to also extend outward, so that the other rolling member 102 also tightly fits the outer wall of the generator shaft. Through the movement of the plug 103b, the extrusion and locking of the two rolling members 102 adjacent to the two ends of the mounting plate 101 are realized at the same time. Similarly, the self-locking member 103 and the rolling member 102 at the other end of the two mounting plates 101 are also extruded in the same way.

[0055] When the two mounting plates 101 are locked by being inserted into each other in this way, all the rolling members 102 at the two ends of the mounting plate 101 are extruded to the outer wall of the generator shaft, forming stable contact and support. Such a design ensures that the position of the mounting plate 101 on the generator shaft is stable and reliable, and the good contact of the rolling member 102 with the shaft reduces the resistance and wear during rotation, ensuring the normal operation of the entire monitoring system.

[0056] The rest of the structure is the same as that of example 2.

[0057] Example 4

[0058] Referring to FIGS. 2-7, the fourth embodiment of the present application is different from the third embodiment in that a plurality of missing grooves 105a are formed on the mounting plate 101, and the mounting seat 105 slides along the missing groove 105a. The mounting seat 105 includes a sliding plate 105b, the sliding plate 105b is provided with a sliding groove 105c, a sliding seat 105d is slidably arranged in the sliding groove 105c, a third spring 105e for pushing the sliding seat 105d to move is arranged in the sliding groove 105c, and the grounding carbon brush 200 is detachably mounted on the sliding seat 105d. The mounting shaft 105h is arranged at the bottom of each sliding plate 105b, the two mounting shafts 105h adjacent to each other are connected in series through the connecting plate 105f, the four connecting plates 105f form a parallelogram frame, and the electric screw 105g is arranged in one of the missing grooves 105a and is screwed to the corresponding mounting shaft 105h.

[0059] It should be noted that in order to ensure that the grounding carbon brush 200 can maintain a stable contact state in the case of wear change of the outer wall of the generator shaft, a special elastic compensation mechanism is designed. The slide plate 105b is a key component, and a slide groove 105c structure is arranged on the slide plate 105b. The slide groove 105c is internally provided with a sliding seat 105d, which can slide freely in the slide groove 105c. It is worth noting that a third spring 105e is also integrated inside the slide groove 105c. The function of the third spring 105e is to push the sliding seat 105d to move towards the direction of tightly abutting the shaft under the action of the spring force, so that no matter whether the size of the carbon brush is reduced due to wear or the contact pressure changes, the spring can automatically adjust to ensure that the grounding carbon brush 200 continuously and tightly contacts the outer wall of the shaft, maintaining good electrical conductivity.

[0060] In addition, the bottom of each slide plate 105b is provided with a mounting shaft 105h, and the mounting shafts 105h are connected by the connecting plate 105f to form a parallelogram frame structure. This structure has the characteristics of good transmission stability and strong synchronization. When one of the slide plates 105b moves under control, the other slide plates 105b will also move synchronously. An electric screw 105g is embedded in one of the slide grooves 105c. The electric screw 105g is connected to the corresponding mounting shaft 105h through threads. The electric screw 105g can be driven by a motor to extend or retract, so as to accurately control the sliding of the mounting seat 105 and the sliding seat 105d on it along the slot 105a, thereby realizing the automatic adjustment and switching of the grounding carbon brush 200 on the shaft, and ensuring that the detection equipment accurately and effectively monitors the shaft current or shaft voltage of the generator.

[0061] When installing the grounding carbon brush 200, the electric screw 105g is started to drive the corresponding mounting shaft 105h to move outward, so that the slide plate 105b fixed to the mounting shaft 105h moves outward along the slot 105a. The outward movement of the slide plate 105b drives the sliding seat 105d fixed thereto to move outward, so as to move the sliding seat 105d to the gap 104a of the containing shell 104. Since the bottom of the grounding carbon brush 200 is provided with a plug hole and the sliding seat 105d is provided with a plug rod, the plug rod is inserted into the plug hole and the grounding carbon brush 200 is moved to the inside of the containing shell 104 by the electric screw 105g. In this way, the grounding carbon brush 200 will not fall off, and the grounding carbon brush 200 is also moved to contact the outer wall of the shaft of the generator. Due to the arrangement of the parallelogram frame, the two mounting seats 105 in each pair of mounting seats 105 move synchronously, so that the two grounding carbon brushes 200 in the same group can be installed and replaced synchronously.

[0062] The remaining structure is the same as that of Example 3.

[0063] Example 5

[0064] Referring to FIG. 2-7, for the fifth embodiment of the present application, which is different from the fourth embodiment, the four grounding carbon brushes 200 are divided into two opposite groups, two of the same group are used at the same time, and the accommodating shell 104 and the mounting seat 105 correspond to the grounding carbon brush 200. The upper end surface of each accommodating shell 104 is provided with a notch 104a, and the side surface is provided with a first through slot 104b, and the first through slot 104b is clamped with the current collecting ring 106, and the side surface of the grounding carbon brush 200 is provided with a second through slot 204, and the second through slot 204 is clamped in the current collecting ring 106. The current collecting ring 106 is divided into two types, which correspond to the four grounding carbon brushes 200 as the same type or two types of these two cases, when the grounding carbon brush 200 is the same type, two current collecting rings 106 are inserted to form a circular ring, and are fixed with a down lead; when the grounding carbon brush 200 is two types, two current collecting rings 106 are respectively connected with a down lead.

[0065] It should be noted that the first through slot 104b on the body of the accommodating shell 104 and the second through slot 204 on the grounding carbon brush 200 are arranged in opposite directions, which allows the current collecting ring 106 to be fixed between the two through slots. When the mounting seat 105 pushes the grounding carbon brush 200 to move towards the inside of the accommodating shell 104, the grounding carbon brush 200 contacts the current collecting ring 106 through its own second through slot 204, realizing effective connection of the circuit; conversely, when the mounting seat 105 drives the grounding carbon brush 200 to move away from the current collecting ring 106 and towards the outside of the accommodating shell 104, the grounding carbon brush 200 is disconnected from the current collecting ring 106, and the circuit cannot be connected. The mounting seat 105 moves in a relative and synchronous manner, ensuring that the grounding carbon brush 200 can smoothly perform the switching operation of the two groups.

[0066] There are two cases for the type configuration of the grounding carbon brush 200:

[0067] When all grounding carbon brushes 200 are of the same type, for example, all are first grounding carbon brushes 201, second grounding carbon brushes 202 or third grounding carbon brushes 203, four grounding carbon brushes 200 of the same type will be assembled on a single mounting component 100, which are attached to the outer wall of the generator shaft in the form of two opposite pairs, and simultaneously detect the surface of the shaft. Adjacent grounding carbon brushes 200 can be replaced with each other. At this time, two semicircular current collecting rings 106 can be spliced into a complete closed current collecting ring 106, and a down lead is arranged at the center of the current collecting ring 106 for grounding, and at the same time, only the current transformer 301 or the voltage sensor 302 needs to be connected with the current collecting ring 106, so that the shaft current or shaft voltage detection task can be completed under this configuration, but it needs to be noted that three such mounting components 100 are required to fully cover the detection requirements under this condition.

[0068] When the grounding carbon brush 200 is divided into two types, i.e. the first grounding carbon brush 201 and the second grounding carbon brush 202, the four grounding carbon brushes 200 on the same mounting component 100 will be arranged according to the principle that adjacent ones are of different types and opposite ones are of the same type, so as to ensure that the two types of grounding carbon brushes 200 can participate in work at each switching. At this time, the current collector ring 106 is designed as two independent arc-shaped parts, each arc-shaped ring is connected with one down conductor, and each down conductor is connected to the current transformer 301 or the voltage sensor 302, so as to realize real-time monitoring of the shaft current or shaft voltage of the generator rotor shaft.

[0069] The rest of the structure is the same as that of Example 4.

[0070] It is important to note that the constructions and arrangements of the application shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in the application. For example, elements shown as integrally formed can be constructed of multiple parts or elements, the position of elements can be reversed or otherwise varied, and the nature or number of elements or positions can be altered or varied. Accordingly, all such variations are intended to be included within the scope of the application. The order or sequence of any process or method steps can be changed or re-sequenced without departing from the scope of the application. Any "means plus function" clauses are intended to cover the structures described herein as performing the recited functionality, and not just structural equivalents, but also equivalent structures. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the application. Accordingly, the application is not limited to the particular embodiments described, but extends to equivalents of which the skilled in the art will appreciate.

[0071] Also, in the interests of providing a concise description of exemplary embodiments, not all features of an actual implementation can be described (i.e., those unrelated to the disclosure of the presently claimed application, or those that are well known in the art).

[0072] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A system for measuring generator shaft voltage and shaft current, the system comprising: The utility model relates to a kind of installation parts (100) for installing ground carbon brush (200) on the rotating shaft of generator near exciter end and steam turbine end respectively, which includes the first ground carbon brush (201) of generator steam turbine end, the second ground carbon brush (202) and the third ground carbon brush (203) of generator exciter end; Monitoring component (300) includes current transformer (301) for monitoring and measuring generator steam turbine end ground current, the current transformer (301) is installed on the line of the first ground carbon brush (201) down conductor and steam turbine grounding point;Voltage sensor (302) for collecting exciter end to ground, steam turbine end to ground, exciter end and steam turbine end voltage, the voltage sensor (302) is installed on the line of the second ground carbon brush (202) down conductor and the third ground carbon brush (203) down conductor;Processing module (303) electrically connected the current transformer (301) and the voltage sensor (302), which is used for real-time analysis of collected voltage and current signal, calculates single peak value, average value, effective value and peak-peak value, and carries out accurate discrimination and analysis, while when the measured value of shaft voltage or shaft current is detected to exceed preset threshold, alarm signal is sent. The processing module (303) includes real-time analysis unit, for real-time analysis of collected voltage and current signal, calculates single peak value, average value, effective value and peak-peak value, and carries out accurate discrimination and analysis through spectrum analysis technology and corresponding data model;Alarm unit, when the measured value of shaft voltage or shaft current is detected to exceed preset threshold, alarm signal is sent;History data storage and query unit is used to store shaft voltage, shaft current waveform history data during generator operation, and allows to call query at any time, so as to serve as the basis for judging whether generator shaft insulation is good.

2. The measuring generator shaft voltage and shaft current system of claim 1, wherein: The installation component (100) includes two installation plates (101) arranged symmetrically, the rotating shaft of the generator is clamped in the two installation plates (101), the inner wall of the installation plate (101) is provided with an extended rolling element (102), the rolling element (102) is attached to the outer wall of the rotating shaft of the generator, the inner part of the installation plate (101) is further provided with a self-locking element (103), the self-locking element (103) is used to lock the two installation plates (101) and push the rolling element (102) to move outward, the side of the installation plate (101) is provided with a plurality of accommodating shells (104), a sliding mounting seat (105) is arranged in each accommodating shell (104) on the side wall of the installation plate (101), and the ground carbon brush (200) is mounted on the mounting seat (105).

3. The system for measuring shaft voltage and shaft current of a generator of claim 1, wherein: ​ 4. The system for measuring shaft voltage and shaft current of a generator of claim 3, wherein: Two mounting plates (101) are formed into a complete ring by the self-locking piece (103), a first accommodating groove (103a) is arranged at one end of each mounting plate (101), a bolt (103b) is slidably arranged in the first accommodating groove (103a), a first spring (103c) is arranged in the first accommodating groove (103a) and is used for resetting the bolt (103b), a lock hole (103d) is arranged at the other end of the mounting plate (101), the bolt (103b) is inserted into the lock hole (103d), and the front end of the bolt (103b) is arranged in a trapezoidal shape.

5. The system for measuring shaft voltage and shaft current of a generator of claim 4, wherein: A second accommodating groove (102a) is arranged at the position close to the two ends of the side wall of the mounting plate (101), the second accommodating groove (102a) is communicated with the first accommodating groove (103a) or the lock hole (103d) respectively, the rolling piece (102) is arranged in the second accommodating groove (102a), the rolling piece (102) comprises a first frame (102b), a second frame (102c) is slidably arranged in the first frame (102b), a second spring (102d) is further arranged in the first frame (102b) and is used for pushing the second frame (102c) to move outward, a rolling wheel (102e) is arranged in the second frame (102c), the inner end of the first frame (102b) is arranged in a trapezoidal head (102f), and the bolt (103b) extrudes the trapezoidal head (102f).

6. The system for measuring shaft voltage and shaft current of a generator of claim 5, wherein: A plurality of missing grooves (105a) are arranged on the mounting plate (101), the mounting base (105) slides along the missing grooves (105a), the mounting base (105) comprises a sliding plate (105b), a sliding groove (105c) is arranged on the sliding plate (105b), a sliding seat (105d) is slidably arranged in the sliding groove (105c), a third spring (105e) is further arranged in the sliding groove (105c) and is used for pushing the sliding seat (105d) to move, and the grounding carbon brush (200) is detachably arranged on the sliding seat (105d).

7. The system for measuring shaft voltage and shaft current of a generator of claim 6, wherein: The four grounding carbon brushes (200) are divided into two groups in opposite directions, two grounding carbon brushes in the same group are used simultaneously, the accommodating shell (104) and the mounting base (105) correspond to the grounding carbon brush (200) one by one.

8. The system for measuring shaft voltage and shaft current of a generator of claim 7, wherein: An installation shaft (105h) is arranged at the bottom of each sliding plate (105b), two adjacent installation shafts (105h) are connected in series through a connecting plate (105f), four connecting plates (105f) form a parallelogram frame, and an electric screw rod (105g) is arranged in one of the missing grooves (105a), and the electric screw rod (105g) is screwed to the corresponding installation shaft (105h).

9. The system for measuring shaft voltage and shaft current of a generator of claim 7, wherein: The upper end surface of each accommodating shell (104) is provided with a notch (104a), and the side surface is provided with a first through slot (104b), and a grounding ring (106) is clamped in the first through slot (104b); the side surface of the grounding carbon brush (200) is provided with a second through slot (204), and the second through slot (204) is clamped in the grounding ring (106).

10. The measuring generator shaft voltage and shaft current system of claim 9, wherein: The grounding ring (106) is divided into two types, and the four grounding carbon brushes (200) are of the same type or two types; when the grounding carbon brushes (200) are of the same type, two grounding rings (106) are inserted to form a ring, and are fixed with a down conductor; when the grounding carbon brushes (200) are of two types, two grounding rings (106) are respectively connected with a down conductor.

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