An analysis method and device for coupling of multiple electric states on a surface of a rotating fan blade

Abstract

The application discloses a kind of analysis method and device of the surface of rotating fan blade multiple electric state coupling, method includes: obtaining the potential distribution data of the insulating sample surface of insulating sample after wind tunnel test with metal disc;Based on the potential distribution data, in combination with charge inversion algorithm, the charge density distribution of the insulating surface sample with metal disc is obtained;Based on the space electric field distribution model in simulation software, in combination with the charge density distribution obtained by inversion, the space electric field under steady state is calculated, and the space electric field distribution diagram of the insulating surface sample with metal disc is obtained.The application realizes the calculation of the charge distribution and space electric field distribution of the surface of rotating fan blade multiple electric state coupling by wind tunnel test, potential distribution measurement, charge inversion and space electric field distribution simulation, and analyzes the law of the surface of rotating fan blade multiple electric state coupling based on the calculation result.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of lightning protection design of wind turbines, and particularly relates to a method and device for analyzing multi-charge state coupling on the surface of rotating wind turbine blades. BACKGROUND

[0002] In recent years, the world wind power has developed rapidly, and the installed capacity of wind turbines has increased rapidly. The wind turbine group is threatened by natural disasters during large-scale application, and the most important natural disaster is that the wind turbine is struck by lightning and cannot operate normally.

[0003] At present, the lightning protection system of the wind turbine blade is usually composed of a lightning arrester embedded on the surface of the blade and an internal grounding down conductor. Under normal circumstances, when the lightning arrester successfully strikes, the lightning is discharged by the down conductor, avoiding the ablation of the blade insulating material. However, it is often found that the blade surface is ablated or broken down, which indicates that the lightning protection system of the blade still has a lightning strike failure.

[0004] The reason for the lightning strike failure is related to the multi-charge process on the insulating surface of the blade. Existing researches believe that there are mainly several charging methods on the insulating surface of the blade. One is friction charging. The tip line speed of a large wind turbine is more than 40 m / s, and when rotating at high speed, the blade surface will collide with air and suspended particles in the air to deposit static charges. The other is corona charging. The potential gradient in the atmosphere is sufficient to cause corona discharge of the lightning arrester or even the down conductor (about 50 kV potential difference exists at 200 m high above the ground in clear weather, and the potential difference is greater in rainy weather).

[0005] At present, only qualitative analysis and speculation are available for the multi-charge process on the insulating surface of the blade, and there is a lack of quantitative characterization of the charging state on the insulating surface of the rotating wind turbine blade and research on how the accumulated charges on the blade surface affect the spatial electric field distribution, which cannot provide a basis for solving the frequent lightning strike failure of the rotating wind turbine blade.

[0006] At present, the simulation charge method (CSM) used in engineering practice is based on the uniqueness principle of electromagnetic field. The continuous distribution of free charges on the electrode surface or the continuous distribution of bound charges on the dielectric interface is replaced by a set of discrete simulation charges. Thus, the spatial electric field distribution generated by the original continuous distribution of charges can be obtained by applying the superposition principle to the field generated by the discrete simulation charges in space, which is an effective method for studying the influence of blade surface charges on spatial electric field distribution. However, how to obtain and set the effective distribution of space charges and obtain the spatial electric field distribution based on the effective distribution of charges and the simulation charge method is still not realized in the prior art. SUMMARY

[0007] To overcome the above deficiencies of the prior art, the present application provides a method and device for analyzing the coupling of multiple charge states on the surface of a rotating fan blade, which realizes the calculation of the charge distribution and the spatial electric field distribution of the coupling of multiple charge states on the surface of a rotating fan blade through wind tunnel testing, potential distribution measurement, charge inversion, and spatial electric field distribution simulation, and analyzes the law of the coupling of multiple charge states on the surface of a rotating fan blade based on the calculation results.

[0008] According to an aspect of the present application, a method for analyzing the coupling of multiple charge states on the surface of a rotating fan blade is provided, which comprises:

[0009] Wind tunnel testing is performed on an insulating surface sample with a metal disc, and the potential distribution data of the surface of the insulating sample after the wind tunnel testing is measured;

[0010] Based on the potential distribution data, the charge density distribution of the insulating surface sample with a metal disc is obtained by combining a charge inversion algorithm;

[0011] Based on a spatial electric field distribution model in a simulation software, the spatial electric field under steady state is calculated by combining the obtained charge density distribution, and a spatial electric field distribution map of the insulating surface sample with a metal disc is obtained.

[0012] As a further technical solution, the method further comprises: removing the residual charge on the insulating surface sample with a metal disc in advance, and placing the sample after the residual charge is removed on a grounded metal plate until before the wind tunnel testing.

[0013] As a further technical solution, the method further comprises:

[0014] The prepared insulating surface sample with a metal disc is placed into a wind tunnel testing platform to perform corona charging wind tunnel testing on the insulating surface.

[0015] The insulating surface sample with a metal disc after the wind tunnel testing is placed into a charge distribution measurement system, and the potential distribution on the surface of the insulating sample is measured by using an electrostatic probe.

[0016] As a further technical solution, the method further comprises: building a wind tunnel testing platform, which comprises a testing section forming a straight-line airflow, a straight guide plate arranged at the bottom of the testing section to guide the airflow, and a ventilation channel formed by the straight connection between the air inlet and the air outlet of the testing section; the insulating surface sample with a metal disc is placed on the straight guide plate, and the insulating surface sample with a metal disc is connected to a current measurement system through a downlead; an upper plate electrode is arranged above the testing section to simulate a thundercloud, and the upper plate electrode is connected to a direct-current high-voltage generator; a lower plate electrode is arranged below the testing section to simulate the ground.

[0017] As a further technical solution, based on the potential distribution data, the charge inversion algorithm is combined to obtain the charge density distribution of the insulating surface sample with the metal disc, including:

[0018] The potential-charge conversion matrix is calculated based on the test model setting;

[0019] The Lanczos-Tikhonvo algorithm is introduced to perform potential-charge inversion;

[0020] After inversion, the surface charge density distribution of the insulating surface sample with the metal disc is output.

[0021] As a further technical solution, the method further includes: changing the test elements, and analyzing the coupling law of the rotating fan blade surface multi-charge state by comparing different test results.

[0022] According to an aspect of the present application, an analysis device for coupling of a rotating fan blade surface multi-charge state is provided, including:

[0023] The first main module is used to obtain the potential distribution data of the insulating sample surface of the insulating surface sample with the metal disc after the wind tunnel test;

[0024] The second main module is used to obtain the charge density distribution of the insulating surface sample with the metal disc based on the potential distribution data and the charge inversion algorithm;

[0025] The third main module is used to calculate the space electric field under the steady state based on the space electric field distribution model in the simulation software and the inversion obtained charge density distribution, to obtain the space electric field distribution diagram of the insulating surface sample with the metal disc.

[0026] According to an aspect of the present application, an analysis system for coupling of a rotating fan blade surface multi-charge state is provided, including: a wind tunnel test platform, a charge distribution measurement system, and the analysis device for coupling of a rotating fan blade surface multi-charge state, the wind tunnel test platform is used to put the insulating surface sample with the metal disc after removing the residual charge to perform the insulating surface corona charging wind tunnel test; the charge distribution measurement system is used to put the insulating surface sample with the metal disc after the wind tunnel test, and the potential distribution of the insulating sample surface is measured by using the electrostatic probe.

[0027] As a further technical solution, the wind tunnel test platform comprises a test section forming a straight airflow, a straight guide plate is arranged at the bottom of the test section to guide the airflow, and the part between the air inlet and the air outlet of the test section is linearly connected to form an air duct; the insulating surface sample with a metal disc is placed on the straight guide plate, and the insulating surface sample with the metal disc is connected to the current measurement system through a down conductor; an upper plate electrode is arranged above the test section to simulate a thundercloud, and the upper plate electrode is connected to a direct current high-voltage generator; a lower plate electrode is arranged below the test section to simulate the ground.

[0028] Compared with the prior art, the beneficial effects of the present application are that:

[0029] (1) The present application takes the insulating surface of a rotating fan blade as the research object, simulates the corona charge distribution on the outer insulating surface under a strong electric field through a wind tunnel test, measures the potential distribution on the surface of the insulating sample through an electrostatic probe method, inverses the surface charge density distribution of the insulating surface sample through a charge inversion algorithm, calculates the spatial electric field distribution of the insulating surface sample with the metal disc in combination with the spatial electric field distribution model in the simulation software, and then analyzes the charge distribution and electric field distribution when the blade surface multi-charging state is coupled according to the spatial electric field distribution of the insulating surface sample with the metal disc.

[0030] (2) The present application obtains different test results by changing the electric field intensity and / or high-speed airflow during the wind tunnel test, forms the law of the rotating fan blade surface multi-charging state coupling based on the multi-charging state coupling analysis of different test results.

[0031] (3) The present application provides a law analysis method of the multi-charging state coupling in the surface charging process of a fan, fills the gap in the current research on the fan surface, and can provide a basis for the future systematic research on fan protection. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 A flowchart of the analysis method of the rotating fan blade surface multi-charging state coupling provided by the embodiments of the present application.

[0034] Figure 2 A structural schematic diagram of the wind tunnel test platform provided by the embodiments of the present application.

[0035] Figure 3(a)-(b) are schematic diagrams of the wind tunnel test box arrangement site provided by the embodiment of the present application.

[0036] Figure 4 (a)-(b) are schematic diagrams of the insulating surface sample with metal disc provided by the embodiment of the present application.

[0037] Figure 5 The charge distribution inversion process schematic diagram provided by the embodiment of the present application.

[0038] Figure 6 The structural schematic diagram of an analysis device for the coupling of the surface of the rotating fan blade and multiple charged states provided by the embodiment of the present application. DETAILED DESCRIPTION

[0039] The present application provides an analysis method for the coupling of the surface of the rotating fan blade and multiple charged states. The method builds an insulating surface corona charged wind tunnel test platform with embedded electrodes and down lead to simulate the electric field environment when lightning occurs in nature and its influence on the ground object, carries out the charge distribution and spatial electric field distribution analysis of the coupling of the surface of the fan and multiple charged states based on the electrostatic probe method and the simulation charge method, and determines the coupling rule of the surface of the rotating fan blade and multiple charged states by comparing different test results.

[0040] The terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover the non-exclusive inclusion, for example, the process, method, system, product or device including a series of steps or units, which is not necessarily limited to the clearly listed steps or units, but can include other steps or units which are not clearly listed or inherent to the process, method, product or device.

[0041] The block diagram shown in the drawings is only a functional entity, which does not necessarily correspond to a physically independent entity. That is, the functional entity can be realized in the form of software, or realized in one or more hardware modules or integrated circuits, or realized in different network and / or processor devices and / or microcontroller devices. The flowchart shown in the drawings is only an exemplary description, which does not necessarily include all contents and operations / steps, and does not necessarily be executed in the described order. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order can be changed according to the actual situation.

[0042] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application. In addition, the technical features in each of the embodiments or in a single embodiment provided by the present application can be combined with each other at will to form new technical solutions, and the combination is not restricted by the order of steps and / or the mode of structural composition, but should be based on the fact that a person of ordinary skill in the art can realize it. When the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0043] The embodiments of the present application provide an analysis method for coupling of multiple electric states on a surface of a rotating fan blade, as shown in the following formula (1) : Figure 1 The method comprises the following steps: performing a wind tunnel test on an insulating surface sample with a metal disc, and measuring potential distribution data of the insulating sample surface after the wind tunnel test; obtaining charge density distribution of the insulating surface sample with the metal disc based on the potential distribution data and in combination with a charge inversion algorithm; and calculating a spatial electric field under a steady state based on a spatial electric field distribution model in simulation software and in combination with the obtained charge density distribution, to obtain a spatial electric field distribution graph of the insulating surface sample with the metal disc.

[0044] In the embodiments of the present application, before the analysis of the coupling of multiple electric states on the surface of the rotating fan blade, the wind tunnel test on the insulating surface sample with the metal disc is further included.

[0045] Before the wind tunnel test, a wind tunnel test platform is further included for simulating airflow and electric field conditions under a lightning background. As shown in the following formula (2) : Figure 2 The wind tunnel test platform comprises a test section for forming a straight airflow, a straight guide plate is arranged at the bottom of the test section for guiding the airflow, and a ventilation channel is formed by connecting the part between the air inlet and the air outlet of the test section in a straight line. The insulating surface sample with the metal disc is placed on the straight guide plate, the surface of the insulating sample is parallel to the bottom of the test section, and is used for simulating a lightning arrester. The insulating surface sample with the metal disc is connected to a current measurement system through a down conductor.

[0046] An upper plate electrode is arranged above the test section for simulating a thundercloud, and the upper plate electrode is connected to a direct current high-voltage generator. An insulating sleeve is arranged at the connection between the upper plate electrode and a line, and a protection resistor is arranged at the connection between the direct current high-voltage generator and the line. A lower plate electrode is arranged below the test section for simulating the ground, and the upper plate electrode and the lower plate electrode are oppositely arranged.

[0047] Optionally, the bottom of the test section is provided with a support for supporting the straight flow guide plate on the test section.

[0048] During the test, the electric field condition of the wind tunnel test can be changed by controlling the parameters of the direct current high voltage generator, and the high speed airflow of the wind tunnel test can be changed by controlling the fan equipment (such as an anemograph) arranged at the air inlet of the test section.

[0049] Optionally, the wind tunnel test platform can further be provided with a high speed camera and an ultraviolet imager for obtaining required images.

[0050] As shown in Figure 2 The air inlet of the test section further forms a power section, a converging section and a stabilizing section, wherein the power section is used for forming an initial airflow, the converging section is used for converging the initial airflow, and the stabilizing section is used for stabilizing the converged airflow.

[0051] The air outlet is sequentially formed with an outlet stabilizing section, a diffusion section and an air outlet section, the outlet stabilizing section is used for stabilizing the airflow through the test section, the diffusion section is used for diffusing the stabilized airflow, and the air outlet section is used for discharging the diffused airflow.

[0052] The on-site arrangement of the wind tunnel test platform provided by the embodiment of the present application is shown in Figure 3 (a)-(b). The insulating surface sample with a metal disc provided by the embodiment of the present application is shown in Figure 4 (a)-(b).

[0053] The wind tunnel test platform designed by the embodiment of the present application forms an electric field environment simulating the lightning cloud and the ground in the nature by using the upper plate electrode to simulate the lightning cloud and the lower plate electrode to simulate the ground, and provides a high speed airflow by the wind tunnel device to simulate the airflow environment on the surface of the blade in high speed motion, so that the airflow and the electric field condition under the lightning background can be truly simulated.

[0054] In the embodiment of the present application, before the wind tunnel test, the operation of removing the surface charge on the outer surface of the insulating surface sample with a metal disc is performed 24 hours in advance, and the sample is placed on the grounded metal plate until the test.

[0055] Further, after removing the residual charge, the metal disc-equipped insulating surface sample after standing is placed in a wind tunnel device according to test requirements, the lower end of the fixing device is connected to an external fixing device to ensure that the insulating sample is firmly and reliably fixed, and the down conductor is connected to the discharge current measurement system to ensure that the discharge current is detected truly and effectively. The whole process is in contact with the metal disc-equipped insulating surface sample through a tweezer and a fixing device to ensure that the metal disc-equipped insulating surface sample is not in direct contact with the outside world. Then, under the conditions of a strong electric field and high-speed airflow, a multi-charging process test is carried out.

[0056] In the embodiment of the present application, after the wind tunnel test, the surface potential distribution of the metal disc-equipped insulating surface sample is measured by using an electrostatic probe method.

[0057] Specifically, after the required test time is reached, the fan device and the direct current high-voltage generator are turned off, the fixing between the devices is released at the first time, and the metal disc-equipped insulating surface sample is taken out by a tweezer, during which it is ensured that the metal disc-equipped insulating surface sample is not in direct contact with the outside world. The metal disc-equipped insulating surface sample is sent to a charge distribution measurement system in a shielding room, the potential distribution on the surface of the insulating sample is measured by an electrostatic probe, and the data is exported.

[0058] It should be noted that the charge distribution measurement system can be realized by using existing mature technology, and the present application does not make redundant description here.

[0059] In the embodiment of the present application, after the potential distribution data is measured, the measured potential distribution data is further imported into a charge inversion algorithm to obtain a charge distribution cloud map of the metal disc-equipped insulating surface sample.

[0060] Optionally, a hybrid method of iterative LBD and Tikhonov regularization algorithm is introduced during charge distribution inversion to improve the accuracy and efficiency of inversion.

[0061] As shown in Figure 5 The charge inversion algorithm specifically includes: calculating a potential-charge conversion matrix based on a test model setting; introducing a Lanczos-Tikhonvo algorithm for potential-charge inversion; after inversion, outputting the surface charge density distribution of the metal disc-equipped insulating surface sample. Here, the LBD method is used to transform the to-be-solved matrix into a low-dimensional double-diagonal matrix, and then the Tikhonov regularization is used to solve the inverse problem, and the regularization solution after each iteration is obtained after repeated iteration.

[0062] Specifically, if the surface to be measured is divided into N identical small units, the relationship between the potential and the charge density σ of the whole surface to be measured can be expressed as:

[0063] The iterative LBD and Tikhonov regularization algorithm is introduced, which is equivalent to solving the least square problem:

[0064]

[0065] The iterative LBD transformation is performed on the H matrix. For two orthogonal subspaces of dimension k (k is much smaller than N), the orthogonal bases are defined as P and Y, respectively, and the following equation is obtained:

[0066] In the process of iterative calculation of the B matrix, the following parameters need to be satisfied:

[0067]

[0068] where, θ1=||y1||,||p i ||2=||y i ||2=1i=1,2,…

[0069] The iterative rule is expressed in matrix form as follows:

[0070]

[0071] where, e1 is the unit vector; e k+1 is the last column of the k+1 dimensional identity matrix; θ k+1 is the k+1 diagonal element of the matrix B k+1 ; P k and Y k are the

[0072]

[0073] After each iteration, Tikhonov regularization is introduced to solve the inverse problem for the obtained lower-dimensional matrix B k

[0074] After k steps of iteration, the residual of the original problem is expressed as

[0075]

[0076] where, f is the solution of the subspace problem; P k+1 is the standard orthogonal matrix. Therefore, the original least square problem is approximated as

[0077]

[0078] where, σ is the column vector of the matrix Y k

[0079] ​​The Tikhonov regularization method is used in each iteration, and a regularized solution after each iteration is obtained as

[0080]

[0081] wherein η k is a regularization parameter when the Tikhonov regularization method is used in each iteration; is a pseudo-inverse of

[0082] In the embodiment of the application, after obtaining the charge density distribution of the insulating surface sample with the metal disc, further comprising: by means of the spatial electric field distribution model composed of 50*50 chargeable density data import grids established in the COMSOL software, combining the charge distribution inversion data results, calculating and processing the spatial electric field problem under the steady state, and obtaining the spatial electric field distribution diagram of the insulating surface sample with the metal disc.

[0083] Specifically, the relationship between the surface electric field distribution caused by the surface charge and the surface charge density distribution can be represented by the following formula:

[0084]

[0085] wherein h ex (x-x', y-y'), h ey (x-x', y-y') and h ez (x-x', y-y') respectively represent the x component, the y component and the z component of the electric field caused by the unit charge at the (x', y') position at the (x, y) position.

[0086] The embodiment of the application takes the insulating surface of a rotating fan blade as the research object, analyzes the charge distribution and the electric field distribution when the blade surface multi-charging state is coupled, builds a corona discharge and wind tunnel test platform containing an embedded electrode and a down conductor, studies the difference in corona charge distribution on the outer insulating surface under a strong electric field, analyzes the influence law of high-speed airflow on the charge distribution, obtains the insulating surface charge density distribution under the multi-charging mode, explores the primary and secondary relationship between the insulating surface friction and corona charging under the action of high-speed airflow and strong electric field, and builds a spatial electric field distribution model based on the theory of the influence of charge distribution on the spatial electric field, studies the influence mechanism and effect of the spatial charge distribution on the spatial electric field in the coupling process of the insulating surface friction charging and corona charging.

[0087] ​The implementation basis of each embodiment of the present application is achieved by a programmed process through a device with processor function. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present application are packaged into various modules. Based on the above-mentioned embodiments, the embodiment of the present application provides an analysis device for coupling of multiple charge states on the surface of a rotating fan blade, which is used to execute the method for coupling of multiple charge states on the surface of a rotating fan blade in the above-mentioned method embodiment.

[0088] Referring to Figure 6 , the device comprises: a first main module configured to obtain potential distribution data of an insulating sample surface of an insulating surface sample with a metal disc after a wind tunnel test; a second main module configured to obtain charge density distribution of the insulating surface sample with the metal disc based on the potential distribution data and in combination with a charge inversion algorithm; and a third main module configured to calculate a spatial electric field of the insulating surface sample with the metal disc under a steady state based on a spatial electric field distribution model in simulation software and in combination with the inversion obtained charge density distribution, so as to obtain a spatial electric field distribution map of the insulating surface sample with the metal disc.

[0089] The analysis device for coupling of multiple charge states on the surface of a rotating fan blade provided by the embodiment of the present application is used for charge distribution and electric field distribution when the surface of the fan blade is coupled with multiple charge states, adopts several modules in Figure 6 , and after obtaining the potential distribution data of the insulating sample surface of the insulating surface sample with the metal disc after the wind tunnel test, the surface charge density distribution of the insulating surface sample is inverted through the charge inversion algorithm, and then the spatial electric field distribution of the insulating surface sample with the metal disc is calculated in combination with the spatial electric field distribution model in the simulation software, and then the charge distribution and electric field distribution when the surface of the fan blade is coupled with multiple charge states are analyzed according to the spatial electric field distribution of the insulating surface sample with the metal disc.

[0090] It should be noted that the device embodiment provided by the present application is used to implement the method in the above-mentioned method embodiment, and is also used to implement the method in other method embodiments provided by the present application. The difference is only that the corresponding function modules are set, and the principle is basically the same as that of the above-mentioned device embodiment provided by the present application. As long as the person skilled in the art improves the modules in the above-mentioned device embodiment on the basis of the above-mentioned device embodiment, refers to the specific technical solutions in other method embodiments, obtains the corresponding technical means through the combination of technical features, and the technical solutions composed of these technical means, as long as the technical solutions have practicality, the corresponding device class embodiment is obtained, which is used to implement the method in other method class embodiments. For example:

[0091] Based on the content of the above device embodiment, as a preferred embodiment, the analysis device for the multi-charge state coupling of the surface of the rotating fan blade provided in the embodiment of the application, the second main module is further used for executing the following instructions:

[0092] Based on the test model setting, a potential-charge conversion matrix is calculated.

[0093] The Lanczos-Tikhonvo algorithm is introduced to perform potential-charge inversion.

[0094] After the inversion is completed, the surface charge density distribution of the insulating surface sample with the metal disc is output.

[0095] Based on the same inventive concept as the foregoing embodiments, the embodiment of the application further provides an analysis system for the multi-charge state coupling of the surface of the rotating fan blade, which comprises: a wind tunnel test platform, a charge distribution measurement system and the analysis device for the multi-charge state coupling of the surface of the rotating fan blade.

[0096] When the analysis system for the multi-charge state coupling of the surface of the rotating fan blade is used to analyze the charge distribution and the electric field distribution in the multi-charge state coupling of the blade surface, the corona charging amount distribution of the external insulating surface under a strong electric field is simulated through the wind tunnel test, the potential distribution of the surface of the insulating sample is measured by the charge distribution measurement system combined with the electrostatic probe method, the surface charge density distribution of the insulating surface sample is inverted through the charge inversion algorithm, the spatial electric field distribution of the insulating surface sample with the metal disc is calculated combined with the spatial electric field distribution model in the simulation software, and then the charge distribution and the electric field distribution in the multi-charge state coupling of the blade surface are analyzed according to the spatial electric field distribution of the insulating surface sample with the metal disc.

[0097] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the application.

Claims

1. A method of analyzing the coupling of multiple charge states on the surface of a rotating fan blade, characterized by, The method comprises the following steps: Wind tunnel test is conducted on an insulating surface sample with a metal disc, and potential distribution data of the insulating sample surface after the wind tunnel test is measured, including: a wind tunnel test platform is built, the wind tunnel test platform comprises a test section forming a straight airflow, a straight guide plate is arranged at the bottom of the test section to guide the airflow, and the part between the air inlet and the air outlet of the test section is linearly connected to form an air duct; the insulating surface sample with a metal disc is placed on the straight guide plate, and the insulating surface sample with a metal disc is connected to a current measurement system through a down conductor; an upper plate electrode is arranged above the test section to simulate a thundercloud, and the upper plate electrode is connected to a direct current high-voltage generator; a lower plate electrode is arranged below the test section to simulate the ground; Based on the potential distribution data, the charge density distribution of the insulating surface sample with a metal disc is obtained by combining a charge inversion algorithm. Based on a space electric field distribution model in a simulation software and the inversion obtained charge density distribution, the space electric field distribution of the insulating surface sample with a metal disc is calculated under a steady state.

2. The analytical method for multiple charge state coupling on the surface of a rotating fan blade according to claim 1, characterized in that, The method further comprises the following steps:

3. The analytical method for multiple charge state coupling on the surface of a rotating fan blade according to claim 1, characterized in that, The residual charge on the insulating surface sample with a metal disc is removed in advance, and the sample after the residual charge is removed is placed on a grounded metal plate until before the wind tunnel test. The method further comprises the following steps: The prepared insulating surface sample with a metal disc is placed in the wind tunnel test platform to conduct a corona charging wind tunnel test on the insulating surface; 4. The analytical method for multiple charge state coupling on the surface of a rotating fan blade according to claim 1, characterized in that, The insulating surface sample with a metal disc after the wind tunnel test is placed in a charge distribution measurement system, and an electrostatic probe is used to measure the potential distribution of the insulating sample surface. Based on the potential distribution data, the charge density distribution of the insulating surface sample with a metal disc is obtained by combining a charge inversion algorithm, including: A potential-charge conversion matrix is calculated based on a test model setting; A Lanczos-Tikhonvo algorithm is introduced to perform potential-charge inversion; 5. The method of claim 1, wherein the method is a method of analyzing the surface multi-charge state coupling of a rotating fan blade, characterized by, After the inversion is completed, the surface charge density distribution of the insulating surface sample with a metal disc is output.

6. An analytical device for the analysis of the surface multi-charge state coupling of a rotating fan blade, for carrying out the method according to any one of claims 1 to 5, characterized by The method further comprises the following steps: By changing test elements, the law of multi-charging state coupling on the surface of a rotating fan blade is analyzed by comparing different test results. The method comprises the following steps: A first main module is used to obtain potential distribution data of an insulating sample surface of an insulating surface sample with a metal disc after a wind tunnel test; 7. An analysis system for the coupling of multiple charge states on the surface of a rotating fan blade, characterized in that, A second main module is used to obtain charge density distribution of the insulating surface sample with a metal disc based on the potential distribution data and by combining a charge inversion algorithm; A third main module is used to calculate a space electric field distribution of the insulating surface sample with a metal disc based on a space electric field distribution model in a simulation software and by combining the inversion obtained charge density distribution. The method comprises the following steps: The wind tunnel test platform, the charge distribution measuring system and the analysis device of the multi-charge state coupling of the rotating fan blade surface according to claim 6 are used for placing the insulating surface sample with the metal disc after removing the residual charge to carry out the insulating surface corona charging wind tunnel test; the charge distribution measuring system is used for placing the insulating surface sample with the metal disc after the wind tunnel test, and the potential distribution of the insulating sample surface is measured by using the electrostatic probe.

8. The analysis system for the coupling of multiple charge states on the surface of a rotating fan blade according to claim 7, wherein, The wind tunnel test platform comprises a test section for forming a linear airflow, a straight guide plate is arranged at the bottom of the test section to guide the airflow, and the part between the air inlet and the air outlet of the test section is linearly connected to form an air duct; the insulating surface sample with the metal disc is placed on the straight guide plate, the insulating surface sample with the metal disc is connected to the current measuring system through a downlead, an upper plate electrode is arranged above the test section to simulate thundercloud, the upper plate electrode is connected to a direct-current high-voltage generator, and a lower plate electrode is arranged below the test section to simulate the ground.

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