Generator set stator structure and stator measurement point arrangement method

Abstract

The embodiment of the present application provides a generator set stator structure and a stator measurement point arrangement method, which relates to the technical field of online monitoring of the operation of hydro-turbine generators, and can detect in real time whether the core punchings in the stator core are pressed against each other. The specific scheme is as follows: comprising: a stator core; a fastening assembly for keeping the stator core in a compressed state; a force measuring assembly, the force measuring assembly including a pressure sensor, the pressure sensor being arranged between the stator core and the fastening assembly, and being used to measure the relative pressure value between the stator core and the fastening assembly. The generator set stator structure provided in this embodiment can detect the compression state of its stator core in real time, without the need to set a corresponding detection assembly on the core punchings, thereby avoiding affecting the stator core; since the detection device is located outside the stator core, it is less interfered by the stator core and has a high measurement resolution; the generator set stator structure provided in this embodiment adopts a nested assembly method, and has a high degree of integrity.

Description

Technical Field

[0001] The present application relates to the technical field of online monitoring of the operation of a hydro-generator, and in particular to a stator structure of a generator set and a method for arranging stator measurement points. Background Art

[0002] The stator core is formed by overlapping multiple core punchings. When the core punchings are not compressed, the electromagnetic and mechanical forces during the operation of the hydro-turbine generator set will cause the core punchings to displace in multiple directions, and the core punchings themselves are prone to damage. At the same time, the loose core punchings may also contact and rub against the through-core screws, damaging the insulation layer on the through-core screws, causing a short circuit, and causing the screws and the contacting core punchings to burn out; it may even cut the insulation of the stator wire rod slots, causing more serious accidents. Therefore, it is necessary to obtain real-time information on whether the multiple core punchings of the stator core are compressed. Summary of the Invention

[0003] The embodiments of the present application provide a stator structure of a generator set and a method for arranging stator measurement points, which can detect in real time whether the core punchings in the stator core are pressed against each other.

[0004] On the one hand, this embodiment provides a stator structure of a generator set, including: a stator core; a fastening assembly for keeping the stator core in a compressed state; a force measuring assembly, the force measuring assembly including a pressure sensor, the pressure sensor being arranged between the stator core and the fastening assembly, and being used to measure the relative pressure value between the stator core and the fastening assembly.

[0005] In some embodiments, the fastening assembly includes: a through screw, which is set to pass through the stator core; a fixing piece, which is respectively arranged on the head and tail sides of the through screw, is connected to the through screw for relative movement and contacts the outer surface of the stator core to adjust the degree of compression of the stator core; and a pressure sensor is arranged between the fixing piece and the stator core.

[0006] In some embodiments, the fixing member includes a pressure plate and a nut arranged in sequence, the pressure plate is sleeved on the outside of the through-core screw, the nut is threadedly connected to the through-core screw, and the force measuring assembly is arranged between the stator core and the nut.

[0007] In some embodiments, the nut is a pressure sensing nut.

[0008] In some embodiments, a spring member is provided between the pressure plate and the nut, and the spring member is sleeved on the outside of the through-core screw.

[0009] In some embodiments, the fixing member further includes an insulating washer, which is sleeved on the outside of the through-core screw and arranged between the nut and the stator core, and the force measuring assembly is arranged on the outside of the insulating washer relative to the stator core.

[0010] In some embodiments, the fixing member located on either side of the through-core screw further includes at least a sleeve and a metal washer. The sleeve and the metal washer are both sleeved on the outside of the through-core screw and are both arranged between the nut and the stator core.

[0011] In some embodiments, a gap is set between the sleeve and the through-core screw.

[0012] In some embodiments, the pressure sensor is a fiber optic pressure sensor.

[0013] In some embodiments, the stator structure of the generator set includes at least two through-core screws, and the force measuring assembly is disposed between a portion of the through-core screws and a fastening assembly of the through-core screws.

[0014] On the other hand, this embodiment also provides a stator measurement point arrangement method, which is applied to the stator structure of the generator set in any of the above embodiments, including: selecting an initial position screw; determining a through-hole screw that is not correlated with the initial position screw and is closest to the initial position screw; and using the distance between the through-hole screw and the initial position screw as the maximum point arrangement interval.

[0015] In some embodiments, determining the through-hole screw that is not correlated with the initial position screw and is closest to it includes: establishing a through-hole screw distribution model based on the resolution of the generator set and the pressure sensor; loading the preload force of all through-hole screws to a preset value; changing the preload force of the initial position screw and determining the corresponding pressure value change of other through-hole screws; among the pressure value changes that are smaller than the resolution of the pressure sensor, determining the through-hole screw corresponding to the maximum value as the through-hole screw that is not correlated with the initial position screw and is closest to it.

[0016] In some embodiments, determining the measurement resolution of the pressure sensor includes: determining the required range of the pressure sensor based on the design load of the through-screw, and selecting the pressure sensor; and obtaining the measurement resolution of the pressure sensor.

[0017] In some embodiments, determining a through-hole screw that is not correlated with the initial position screw and is closest to it includes: loading the preload force of all through-hole screws to a preset value; changing the preload force of the initial position screw, taking the through-hole screw to be determined whether it is correlated as the target screw, and measuring the change in pressure value at the target screw; taking the ratio of the change in pressure value at the target screw to the change in the preload force of the initial position screw as the actual influencing factor; if the actual influencing factor is greater than or equal to the preset influencing factor threshold, determining that the target screw is correlated with the initial position screw; if the actual influencing factor is less than the preset influencing factor threshold, determining that the target screw is not correlated with the initial position screw; determining a target screw that is not correlated with the initial position screw and is closest to the initial position screw at a distance LM0.

[0018] In some embodiments, determining whether there is a through screw that is correlated with the initial position screw also includes: establishing a through screw distribution model based on the resolution of the generator set and the pressure sensor; loading the preload force of all through screws to a preset value; changing the preload force of the initial position screw to determine the corresponding pressure value change of other through screws; among the pressure value changes that are smaller than the resolution of the pressure sensor, determining the through screw corresponding to the maximum value and its distance LM1 from the initial position screw; determining the minimum value between LM0 and LM1 as the maximum distribution point interval.

[0019] In some embodiments, determining the through-hole screw that is not correlated with the initial position screw and is closest to it includes: loading the preload force of all through-hole screws to a preset value; changing the preload force of the initial position screw and measuring the change in pressure value at other through-hole screws; among the through-hole screws for which the measured value of the pressure value change is 0, determining the through-hole screw that is closest to the initial position screw as the through-hole screw that is not correlated with the initial position screw and is closest to it.

[0020] In some embodiments, the change of the initial position screw preload force includes at least two change levels, and the relevance determination of the target screw is obtained according to different adjustment levels.

[0021] In some embodiments, the pre-tightening state of all through-screws is 100% pre-tightening, and the change of the initial screw pre-tightening force is achieved by adjusting to different loosening levels, and the loosening levels include: first level, [85%, 100%] of the through-screw pre-tightening load; second level, [70%, 85%] of the through-screw pre-tightening load; third level, [60%, 70%] of the through-screw pre-tightening load; fourth level, [10%, 60%] of the through-screw pre-tightening load; fifth level, [0, 10%] of the through-screw pre-tightening load.

[0022] Beneficial effects:

[0023] (1) The stator structure of the generator set provided in this embodiment can detect the compression state of its stator core in real time, without the need to set a corresponding detection component on the core punching sheet, thereby avoiding any influence on the stator core; because the detection device is located outside the stator core, it is less interfered by the stator core and has a high measurement resolution;

[0024] (2) The stator structure of the generator set provided in this embodiment adopts a nested assembly method, which has high integrity;

[0025] (3) This embodiment provides a stator measurement point arrangement method that minimizes the number of measurement points while ensuring high accuracy, and obtains a high-accuracy and high-economic stator core screw measurement point arrangement scheme, which provides strong support for the overall compression state assessment and fault warning of the hydro-generator core, provides a scientific basis for the safe and reliable operation of the hydro-generator, and provides a reliable reference for the condition inspection and optimized operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is a schematic structural diagram of a stator structure of a generator set provided in some embodiments of the present application;

[0028] Figure 2 is another structural schematic diagram of a generator set stator structure provided in some embodiments of the present application;

[0029] Figure 3 is a schematic structural diagram of a force measurement assembly provided in some embodiments of the present application;

[0030] Reference numerals:

[0031] 1. Stator core; 10. Through-core screw; 201. Nut; 202. Spring; 203. Insulating washer; 204. Sleeve; 205. Metal washer; 30. Force measuring assembly. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0034] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0035] The use of "suitable for" or "configured to" in this application is intended to be open and inclusive language, and does not exclude devices that are adapted or configured to perform additional tasks or steps. In addition, the use of "based on" is intended to be open and inclusive, as a process, step, calculation, or other action that is "based on" one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0036] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0037] On the one hand, if Figures 1 to 3 As shown, this embodiment provides a stator structure of a generator set, including a stator core 1, a fastening assembly and a force measuring assembly 30; the fastening assembly is used to keep the stator core 1 in a compressed state; the force measuring assembly 30 includes a pressure sensor, which is arranged between the fastening assembly and the stator core 1 and is used to measure the relative pressure value between the fastening assembly and the stator core 1.

[0038] In the above embodiment, during the operation of the generator set, the compression state of the stator core 1 is affected by a variety of factors. The thermal aging of the paint film on the core punching sheets and vibrations caused by hydraulic, mechanical, and electromagnetic factors are also important reasons for the deterioration of the compression state of the stator core 1. Long-term vibrations in the radial, axial, and tangential directions will gradually deteriorate the compression state of the stator core 1. If not discovered in time, an operational accident will occur, causing serious economic losses. The above embodiment sets a force measuring assembly 30 between the fastening assembly and the stator core 1, and obtains the relative pressure value between the stator core 1 and the fastening assembly during the operation of the generator set through the pressure sensor of the force measuring assembly 30. In the event that the stator core 1 becomes loose, the pressure between the stator core 1 and the fastening assembly will decrease. The pressure sensor set between the stator core 1 and the fastening assembly can detect the abnormal decrease in pressure (that is, the detected pressure is less than the preset pressure value), and then it can be determined that the stator core 1 is loose.

[0039] In the above embodiment, the force measuring assembly 30 is arranged outside the stator core 1. There is no need to arrange the force measuring assembly 30 between the core punchings of the stator core 1. This can be immune to electromagnetic interference and there is no need to modify the stator core 1 itself.

[0040] In some embodiments, the fastening assembly includes a through screw 10 arranged through the stator core 1, and fixing parts are respectively provided on the head and tail sides of the through screw 10. The fixing parts are connected to the through screw 10 for relative movement. The fixing parts are in contact with the outer surface of the stator core 1. The fixing parts are adjusted by moving relative to the through screw 10 to adjust the degree of compression on the stator core 1. The pressure sensor is arranged between the fixing part and the stator core 1 to detect the axial stress of the through screw 10 through the fixing part, thereby obtaining the looseness of the stator core 1.

[0041] In the above embodiment, the stator core 1 is pre-tightened by the fixing members. In the above embodiment, fixing members are provided on both sides of the stator core 1 to adjust the degree of compression of the stator core 1, thereby achieving pre-tightening of the generator set before operation; a force measuring assembly 30 is then provided between the fixing members and the stator core 1 to measure the looseness of the stator core 1.

[0042] The above embodiment can adapt to the aspect ratio of the through-screw 10 without changing the structure of the through-screw 10, and achieves highly accurate online monitoring of the axial stress of the through-screw 10, eliminating the monitoring blind spot of this important component. After the generator set has been running for a long time, if the force measuring assembly 30 fails, it is only necessary to replace the force measuring assembly 30 on both sides of the through-screw 10, without having to operate the stator core 1, which is convenient for maintenance and low in cost. By setting the force measuring assembly 30 between the fixing member and the stator core 1, the change in the relative pressure value between the two is measured, and then the operating condition of the generator set is obtained.

[0043] In some embodiments, the fixing member includes a pressure plate and a nut 201 arranged in sequence outward along the stator core 1, and the through-core screw 10 is provided with an external thread matching the nut 201 to achieve a threaded connection between the nut 201 and the through-core screw 10, thereby driving the pressure plate to achieve the preload setting of the stator core 1. On the other hand, by providing a pressure plate in contact with the stator core 1, the contact area between the fixing member and the stator core 1 can be effectively increased, and the connection stability between the fixing member and the stator core 1 can be improved. At the same time, it can effectively reduce the damage to the stator core 1 caused by the narrow force area between the fixing member and the stator core 1 and the long-term pressure of the fixing member on the stator core 1. The force measuring component 30 is arranged between the stator core 1 and the nut 201, and can be selectively arranged between the nut 201 and the pressure plate, or between the pressure plate and the stator core 1, both of which can realize the detection of the relative pressure value between the fixing member and the stator core 1.

[0044] In some embodiments, the nut 201 can adopt a pressure sensor nut 201. The pressure sensor and the nut 201 are set as an integrated whole, which reduces the parts that need to be installed and facilitates the installation of the overall equipment; at the same time, during the installation process, when the nut 201 is used to pre-tighten the stator core 1, the pre-tightening force given to the stator core 1 by the nut 201 can be monitored in real time; with this setting, the pre-tightening force of the nut 201 on the stator core 1 can be accurately adjusted according to the use requirements of the generator set.

[0045] In some embodiments, a spring member 202 is provided between the pressure plate and the nut 201. The spring member 202 is sleeved on the outside of the through-thread screw 10. The provision of the spring member 202 can provide a preload force for the generator set stator structure during operation. When the stator core 1 becomes loose, the spring member 202 provides an adaptively adjustable force. Through the compression deformation of the spring member 202, the stator core 1 is re-tightened to prevent the loose stator core 1 from affecting the generator set stator structure. During early adjustment of the preload force, the nut 201 can be adjusted to a certain amount of compression to provide the preload force for the spring member 202. During later maintenance, while the spring member 202 still has a certain service life, the preload force of the spring member 202 can be adjusted again through the nut 201. The spring member 202 and the force measuring assembly 30 do not functionally affect each other, and their positions can be adjusted arbitrarily while ensuring that both can function properly. The spring member 202 can be a disc spring.

[0046] In some embodiments, the fixing member further includes an insulating washer 203, which is sleeved on the outside of the through-core screw 10, and the insulating washer 203 is provided between the nut 201 and the stator core 1, and the force measuring assembly 30 is provided on the outside of the insulating washer 203 relative to the stator core 1. The provision of the insulating washer 203 can prevent the components located on the outside of the insulating washer 203 from being affected, and can effectively provide the measurement resolution of the force measuring assembly 30. On the other hand, relative to not providing the insulating washer 203, the portion of the through-core screw 10 that the fixing member contacts may also cause the outer bonding layer of the through-core screw 10 to be damaged due to friction with the fixing member and the through-core screw 10, resulting in a short circuit. The provision of the insulating washer 203 can effectively prevent the through-core screw 10 located on the outside of the stator core 1 from short circuiting, thereby improving the stability of the equipment.

[0047] In some embodiments, the fixing member on either side of the through-screw 10 further includes at least a sleeve 204, which is sleeved on the outside of the through-screw 10. The sleeve 204 can limit the through-screw 10, reducing the relative movement of the through-screw 10, thereby reducing the contact between the through-screw 10 and the stator core 1, and reducing the probability of relative friction between the two. The fixing member on either side of the through-screw 10 further includes at least a metal washer 205, which is sleeved on the outside of the through-screw 10. The metal washer 205 has the advantage of good stability in use, which helps to provide stability in use of the entire device.

[0048] Among them, a gap is set between the sleeve 204 and the through-core screw 10, and the gap between the sleeve 204 and the through-core screw 10 is smaller than the gap between the through-core screw 10 and the stator core 1. While the sleeve 204 limits the through-core screw 10 and reduces the frequency of contact with the stator core 1, it also facilitates the installation between the sleeve 204 and the through-core screw 10.

[0049] In some embodiments, the pressure sensor is a fiber optic pressure sensor. This environment is complex and subject to significant electromagnetic interference, making it difficult for electrical sensors to meet monitoring accuracy requirements. In this embodiment, the fiber optic pressure sensor, with its low susceptibility to electromagnetic interference, effectively addresses this issue and further improves the anti-interference capability of the force measurement assembly 30.

[0050] In some embodiments, the stator structure of the generator set includes at least two through-hole screws 10, and force measuring assemblies 30 are installed between some of the through-hole screws 10 and their fastening assemblies. Adjacent or nearby through-hole screws 10 are correlated. When one or some of them become loose, the adjacent or nearby through-hole screws 10 equipped with force measuring assemblies 30 can also be detected. Therefore, it is not necessary to install force measuring assemblies 30 on all through-hole screws 10. In this embodiment, at least some of the through-hole screws 10 are used for the stator core 1 compression state detection device to form measuring points on the surface of the stator core 1. Through the multiple distributed measurement points, the overall compression state of the stator core 1 can be detected.

[0051] In another aspect, this embodiment further provides a method for arranging measurement points on a stator core 1, applicable to the stator structure of a generator set according to any of the aforementioned embodiments. The method comprises the following steps: selecting an initial position screw, determining a through-core screw 10 that is unrelated to the initial position screw and closest to the initial position screw, and using the distance between the through-core screw 10 and the initial position screw as the maximum measurement point arrangement interval. Based on this maximum measurement point arrangement interval, measurement points are arranged on the corresponding stator core 1 in the generator set.

[0052] The above embodiment can detect the looseness state of the stator core 1 at various positions of the stator structure of the generator set while arranging as few measuring points as possible, while ensuring the detection performance, it can also effectively reduce costs and improve economy.

[0053] In some embodiments, a distribution model of the through-hole screw 10 is established based on the resolution of the generator set and the pressure sensor, and the simulation measurement points are based on the through-hole screws 10 distributed on the stator core 1, and the measurement resolution of a pressure sensor is preset. First, the preload force of all measurement points is loaded to the preset value; the preload force of the initial position screw in the simulation measurement point is changed to obtain the corresponding pressure value changes of all other through-hole screws 10. The display values ​​of other through-hole screws 10 include those that can display values ​​and those that cannot display values ​​(or the displayed value is 0). The positions of the through-hole screws 10 that cannot be displayed are not considered; the pressure value changes of all through-hole screws 10 that can be displayed are compared with the measurement resolution of the preset pressure sensor to obtain several measurement points with a value less than the measurement resolution of the preset pressure sensor. Among these positions, the through-hole screw 10 with the largest pressure value change is selected, and the distance between the through-hole screw 10 and the initial position screw is used as the maximum distribution point interval. At this time, the maximum distribution point interval is LM1.

[0054] The above embodiment uses computer modeling to place the measurement point arrangement process in the model to obtain the maximum point arrangement interval, without the need for manual measurement of the through-core screw 10 in sequence.

[0055] The preset preload force is 100% preload force when the stator core 1 is fully preloaded. In the measurement point arrangement method, the suspended preload force may be 100% preload force or other preload force set to be less than 100%.

[0056] In some other embodiments, determining the through-hole screw 10 that is not correlated with the initial position screw and is closest to the initial position screw includes the following steps: first, the preload force of all through-hole screws 10 is loaded to a preset value, the preload force of the initial position screw is changed, and the change in the pressure value at the target screw is measured. The ratio of the change in the pressure value at the target screw to the change in the initial position screw is used as the actual influencing factor; a threshold value of the influencing factor is preset, and the actual influencing factor of the initial position screw on the target screw is obtained by the above method, and the actual influencing factor is compared with the preset influencing factor threshold. If the influencing factor of the initial position screw on the target screw is greater than or equal to the preset influencing factor threshold, it is determined that the target screw is correlated with the initial position screw; if the influencing factor of the initial position screw on the target screw is less than the preset influencing factor threshold, it is determined that the target screw is not correlated with the initial position screw. Based on the above method, a maximum distribution point interval LM0 can be obtained.

[0057] The above embodiment can realize direct modification of the existing generator set. By setting multiple measuring points on the stator core 1, it can provide strong support for the overall compression state assessment and fault warning of the stator core 1 of the turbine generator, provide a scientific basis for the safe and reliable operation of the turbine generator, and provide a reliable reference for the status inspection and optimized operation of the unit.

[0058] In some embodiments, the two aforementioned embodiments are used simultaneously for comparison, with a relatively smaller value between LM0 and LM1 selected as the maximum spacing between measurement points to guide the placement of measurement points. The smallest value is selected to ensure greater performance in detecting the compression state of the stator core 1 of the generator set stator structure.

[0059] In some other embodiments, a method for determining a through-hole screw 10 that is not correlated with the initial position screw and is closest to the initial position screw includes the following steps: obtaining a measurement resolution of a pressure sensor; loading the preload of all through-hole screws 10 to a preset value, taking any through-hole screw 10 of the stator structure of the generator set as the initial position screw, and taking any other through-hole screw 10 that needs to be determined whether it is correlated as the target screw; changing the preload of the initial position screw, measuring the change in pressure value at the target screw, and comparing the change in pressure value of the target screw with the measurement resolution of the pressure sensor; if the change in pressure value of the target screw is greater than or equal to the measurement resolution of the pressure sensor, determining that the target screw is correlated with the initial position screw; if the change in pressure value of the target screw is less than the measurement resolution of the pressure sensor, determining that the target screw is not correlated with the initial position. Based on the above method, a maximum point spacing LM1 can be obtained.

[0060] Among them, the method for determining the measurement resolution of the pressure sensor includes the following steps: determining the load of the through-core screw 10 used, and selecting a pressure sensor with a suitable range of the force measuring component 30 based on the load stress of the through-core screw 10; and obtaining the measurement resolution of the pressure sensor through experiments based on the selected pressure sensor.

[0061] The load on the through-core screw 10 is related to one or more of the following parameters: the inter-sheet pressure of the core punching, the effective core compression area, the number of screws, and the screw diameter. The pressure sensor is selected based on its range being greater than the load on the through-core screw 10. Furthermore, the pressure sensor's range should not be too large. If the pressure sensor's range is too large, the minimum pressure change that the pressure sensor can accurately measure will be reduced, thereby reducing measurement accuracy. In some examples, the pressure sensor's range can be selected to be 1.2 to 2 times that of the through-core screw 10.

[0062] In some embodiments, the method for obtaining the influence factor of the initial position screw on the target screw includes the following steps: when the generator set is not working, on the stator core 1, select a through-core screw 10 as the initial position screw, increase or decrease the preload force of the initial position screw, select another through-core screw 10 as the target screw, measure the change in the pressure value of the target screw, and compare the change in the pressure value of the target screw with the change in the preload force of the initial position screw, and the obtained value is used as the actual influence factor. If the influence factor is 0, it means that the state of the initial position screw will not affect the target screw; if the influence factor is 1, it means that the state of the initial position screw is closely related to the target screw. According to demand, a threshold value of the influence factor is preset. If the influence factor of the target screw is less than the preset threshold value of the influence factor, a measuring point is set at the target screw.

[0063] The impact factor threshold is determined based on the generator's power, usage, and operation and maintenance requirements. It should be neither too high nor too low. A too high threshold would result in adjacent measurement points being too close together, increasing generator modification or production costs, which is not worth the cost for low-power generators. A too low threshold would result in adjacent measurement points being too far apart, resulting in insensitive detection and an inability to accurately capture the generator's operating conditions.

[0064] In some embodiments, the change of the initial screw preload force includes at least two change levels, and the relevance determination of the target screw is obtained according to different adjustment levels.

[0065] In the above embodiment, the maximum distribution point spacing obtained by the final measurement varies depending on the amount of change in the initial screw preload. This is because, if the initial screw preload change is small, the initial screw's impact on the other through-hole screws 10 will also be small, and the maximum distribution point spacing obtained by the final measurement will also be smaller. In this case, corresponding to different levels of preload adjustment, different levels of maximum distribution point spacing are obtained. Ultimately, based on the change in the pressure value of the through-hole screw 10 at the measurement point, the looseness of the other through-hole screws 10 can be accurately determined.

[0066] Among them, the pre-tightening state of all through screws 10 is 100% pre-tightening, and the change of the initial position screw pre-tightening force is achieved by adjusting to different loosening levels, and the loosening levels include: first level, [85%, 100%] of the pre-tightening load of the through screw 10; second level, [70%, 85%] of the pre-tightening load of the through screw 10; third level, [60%, 70%] of the pre-tightening load of the through screw 10; fourth level, [10%, 60%] of the pre-tightening load of the through screw 10; fifth level, [0, 10%] of the pre-tightening load of the through screw 10.

[0067] Through the above embodiment, different looseness levels are set and given a certain range. First, a range threshold can be provided. For example, the first looseness level is set to 85% of the preset pre-tightening force of the through screw 10, and other preset pre-tightening forces greater than 85% can be measured; and different looseness conditions are corresponded to the corresponding working conditions during actual production use, providing a guiding basis for production use.

[0068] In some embodiments, the method for obtaining a through-hole screw 10 that is not correlated with the initial position screw and is closest to the initial position screw includes the following steps: taking the through-hole screw 10 to be determined whether it is correlated as the target screw; if the target screw is correlated with the initial position screw, then continuing to select a through-hole screw 10 that is farther from the initial position screw relative to the target screw as the target screw, and determining its correlation again; if the target screw is not correlated with the initial position screw, then continuing to select a through-hole screw 10 that is closer to the initial position screw relative to the target screw as the target screw, and determining its correlation again; and repeating the above steps according to whether the target screw is correlated until a through-hole screw 10 that is not correlated with the initial position screw and is closest to the initial position screw is obtained.

[0069] In the actual process of obtaining the target screw, the relatively distant screw is first selected as the target screw (that is, the adjacent through-core screw 10 closest to the initial position screw is not directly measured). When the actual influence factor of the initial position screw on the relatively distant target screw does not reach the preset influence factor threshold, then there is no need to measure the relatively close screw; if the actual influence factor of the initial position screw on the relatively distant target screw exceeds the influence factor threshold, then the relatively close screw needs to be measured again to avoid missing the measuring point and incomplete measurement of the generator set stator structure.

[0070] In the above embodiment, after the through-screw 10 and the force measuring assembly 30 are selected, the arrangement of adjacent measuring points is obtained, which can guide production and manufacturing, determine the optimal distribution interval of the axial stress measuring points of the generator through-screw 10, and minimize the number of measuring points while ensuring high accuracy, thereby obtaining a highly accurate and economical measurement point arrangement scheme for the through-screw 10 of the generator stator core 1.

[0071] In some embodiments, the initial screw preload is adjusted to different looseness levels, including: Level 1, [85%, 100%] of the load on the through-core screw 10; Level 2, [70%, 85%] of the load on the through-core screw 10; Level 3, [60%, 70%] of the load on the through-core screw 10; Level 4, [10%, 60%] of the load on the through-core screw 10; and Level 5, [0%, 10%] of the load on the through-core screw 10. The initial screw preload is selectively adjusted according to the different looseness levels to ensure efficient preload adjustment.

[0072] Among them, the pressure sensor can be connected to the alarm signal, and different alarm levels can be set according to the looseness level. During the initial position screw preload adjustment process, when it is adjusted to the corresponding level, the alarm will send a corresponding alarm signal to remind the operator whether the preload has reached the corresponding adjustment degree.

[0073] This embodiment also provides a unit loosening warning method. Under specified working conditions, the change in the actual stress value measured by the through-screw 10 relative to the preset stress value is compared with the preset stress value, and the ratio section is selected as the warning level. For example, if the ratio of the actual stress value relative to the preset stress value to the preset stress value is between 85% and 100%, it is judged to be good; when the ratio is between 70% and 85%, it is judged to require attention; when the ratio is between 60% and 70%, it is judged to be preliminary loose; when the ratio is between 10% and 60%, it is judged to be seriously loose; when the ratio is between 0 and 10%, it is judged to be suspected of fracture. Of course, the above is only an example. According to the different operation and maintenance requirements of the unit, the above ratio range and its warning level can be reasonably changed to meet actual needs.

[0074] In combination with a stator core 1 measuring point arrangement method provided in the above embodiment, after obtaining the influence factor value between adjacent measuring points, the influence factor value between the through-hole screws 10 at adjacent measuring points can be obtained (according to the distance from the initial position screw, there will be a certain linear relationship between the pressure value change of the through-hole screws 10 at adjacent measuring points and the initial position screw). When the pressure value change trend of the through-hole screws 10 at adjacent measuring points is abnormal, it can also assist in judging that the through-hole screws 10 near the measuring points may be abnormally loose.

[0075] The above embodiment can further detect the looseness of the through-hole screw 10 at non-measuring point positions by setting measuring points, thereby achieving more comprehensive monitoring performance.

[0076] The above is a detailed introduction to the stator structure of a generator set and the stator measurement point arrangement method provided in the embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A stator measurement point arrangement method, applied to the stator structure of a generator set, characterized in that: The stator structure of the motor group includes: stator core; A fastening assembly for keeping the stator core in a compressed state; and A force measuring assembly, the force measuring assembly comprising a pressure sensor, the pressure sensor being disposed between the stator core and the fastening assembly and being used to measure a relative pressure value between the stator core and the fastening assembly; The stator measuring point arrangement method includes: Select the initial position screw; Determine the closest through-hole screw that is not related to the initial position screw; and The distance between the through screw and the initial position screw is the maximum spacing between the points; The through-hole screw that is determined to be not correlated with the initial position screw and is closest to the initial position screw includes: Establishing a through-screw distribution model based on the resolution of the generator set and the pressure sensor; Load the preload force of all through-screws to the preset value; Change the preload force of the initial screw to determine the corresponding pressure change of other through-hole screws; and Among the pressure value changes that are smaller than the resolution of the pressure sensor, the through-hole screw corresponding to the maximum value is determined as the through-hole screw that has no correlation with the initial position screw and is closest to it; The determined screw and the closest through-core screw have no correlation with the initial position screw, including: Load all through-screw preloads to the preset value; The pre-tightening force of the screw at the initial position is changed, and the through-core screw to be determined whether it has correlation is used as the target screw, and the change in the pressure value at the target screw is measured; The ratio of the change in the pressure value at the target screw to the change in the screw preload at the initial position is used as the actual influencing factor; If the actual impact factor is greater than or equal to the preset impact factor threshold, it is determined that the target screw is related to the initial position screw; If the actual impact factor is less than the preset impact factor threshold, it is determined that the target screw has no relevance to the initial position screw; and Determine a target screw that has no correlation with the initial position screw and is closest to the initial position screw at a distance LM0.

2. The stator measurement point arrangement method according to claim 1, characterized in that: The measurement resolution of the pressure sensor is determined by: Determine the required range of the pressure sensor based on the design load of the through-screw and select the pressure sensor; Get the measurement resolution of the pressure sensor.

3. The stator measurement point arrangement method according to claim 1, characterized in that: The determination of whether the through-core screw is correlated with the initial position screw further includes: Establishing a through-screw distribution model based on the resolution of the generator set and the pressure sensor; Load the preload force of all through-screws to the preset value; Change the preload force of the initial screw to determine the corresponding pressure change of other through-hole screws; Among the pressure value changes that are smaller than the resolution of the pressure sensor, determine the through screw corresponding to the maximum value and the distance LM1 between the through screw and the initial position screw; Determine the minimum value between LM0 and LM1 as the maximum point spacing.

4. The stator measurement point arrangement method according to claim 1, characterized in that: The determined screw and the closest through-core screw have no correlation with the initial position screw, including: Load all through-screw preloads to the preset value; The pre-tightening force of the initial screw is changed, and the change in pressure value at other through-core screws is measured; Among the through-hole screws whose measured value of the pressure value change is 0, the through-hole screw closest to the initial position screw is determined as the through-hole screw that has no correlation with the initial position screw and is closest to it.

5. The stator measurement point arrangement method according to any one of claims 1 to 4, characterized in that: The change of the initial position screw preload force includes at least two change levels, and the relevance determination of the target screw is obtained according to different adjustment levels.

6. The stator measurement point arrangement method according to claim 5, characterized in that: All through-screws are preloaded at 100%. The initial screw preload is changed by adjusting to different looseness levels, including: First level, [85%, 100%] of the through screw preload; The second level is [70%, 85%] of the preload of the through screw; The third level is [60%, 70%] of the preload of the through-screw; Level 4: [10%, 60%] of the through-screw preload; Level 5: [0, 10%] of the through-screw preload.

7. The stator measurement point arrangement method according to any one of claims 1 to 4, characterized in that: The fastening assembly comprises: A through-core screw is provided to penetrate the stator core; The fixing members are respectively provided at the head and tail sides of the through-core screw, are connected to the through-core screw for relative movement, and are in contact with the outer surface of the stator core to adjust the degree of compression of the stator core; The pressure sensor is arranged between the fixing member and the stator core.

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