Active lightning protection system and use method thereof

Abstract

The invention discloses an active lightning protection system and a use method thereof. According to the invention, lightning arresting prevention instead of lightning attraction in a local area is taken as a guiding idea, and the lightning arresting device can interact with the cascade leader of lightning, so that induced charges of a blade in a protected area are neutralized with heteropolar charges at the far end of the blade by using ground charges through the device; therefore, the inductive charge constraint of the near-thunder cloud is reduced, and the thunder and lightning can overflow to the cascade pilot of thunder and lightning in time, and the cascade pilot is neutralized. The electric charges in the air tend to be homogenized, so that the intensity of an electric field above a protected object cannot reach a numerical value of air breakdown, a main discharge channel of thunder and lightning is changed, the occurrence of ground-to-ground lightning return stroke discharge in a protection area is effectively prevented, direct lightning is avoided in the protection area, and the ground-to-ground lightning density in the protected area is greatly reduced. Therefore, the method thoroughly changes the traditional fan lightning protection concept, is applied to the field of wind power, and can effectively reduce the damage of blades and a control system caused by lightning stroke.

Description

Technical Field

[0001] The present invention belongs to the technical field of active lightning protection, and specifically relates to an active lightning protection system and a use method thereof. Background Art

[0002] Since the development of the wind power industry, a large number of mountain wind turbine blades have been damaged by lightning and need maintenance. According to relevant data, the lightning strike problem of high-altitude wind farms is a problem that plagues the world's wind power industry. The transmission lines of some wind farms are tripped by lightning more than a dozen times a year. However, since wind power generation is still in a period of rapid construction, this problem has not received much attention from relevant wind power generation companies in the world.

[0003] However, the world's wind power industry has always adopted the traditional lightning protection mode. This technology uses lightning rods on wind turbine blades to introduce lightning into the earth's discharge flow for lightning protection. This method does not cause obvious damage to low-altitude areas with smaller lightning currents, but its disadvantages are quite significant in high-altitude wind farms. As the wind farm operates for a longer time, the probability of lightning strike accidents in high-altitude wind farms caused by traditional lightning protection technology will gradually increase. Because the longer the wind farm operates, the greater the probability of multiple lightning strikes accumulating damage and causing damage to the wind turbine blades; in addition, the grounding effect of traditional lightning protection deteriorates with the use of time, which eventually leads to a decrease in lightning protection effect.

[0004] At the same time, wind turbine blade damage and transmission line tripping due to one or more lightning strikes will not only increase the operation and maintenance costs of the wind farm, but more importantly, the wind farm will also reduce power generation and may not be able to complete the planned power generation. If the increased operation and maintenance costs, reduced power generation income and power generation reputation loss are comprehensively calculated, it is estimated that the wind farm will lose at least one million yuan each year. Summary of the invention

[0005] The purpose of the present invention is to provide an active lightning protection system and a method for using the same in order to solve the above-mentioned problems.

[0006] The technical solution adopted by the present invention is as follows: an active lightning protection system, the system comprising: an active lightning protection device, a ground charge neutralization current detection device and a monitoring center;

[0007] The active lightning protection device comprises: a fan blade electrode, a high-energy adaptive impedance converter, and a grounding conductor;

[0008] The active lightning protection device neutralizes the charge in the lightning leader to prevent the occurrence of return discharge, thereby protecting the wind turbine from damage caused by lightning.

[0009] The ground charge neutralization current detection device comprises: a current sensor, a memory, and a GPRS module;

[0010] The ground charge neutralization current detection device monitors the magnitude, time and frequency of ground charge current, evaluates the lightning protection effect, and provides remote maintenance function;

[0011] The monitoring center includes: a server, a database, analysis software, and a user interface;

[0012] The monitoring center receives and analyzes ground charge current data, evaluates lightning protection effects, and provides remote maintenance functions.

[0013] In a preferred embodiment, the fan blade electrode uses copper alloy, which has good conductivity and corrosion resistance and low cost. The fan blade electrode is in the shape of a mesh electrode, which covers the surface of the blade and can effectively induce and neutralize the charge. The fan blade electrode is designed according to the blade size. For a blade with a length of 50 meters, the spacing of the electrode grid can be designed to be 1 meter. The fan blade electrode uses an adhesive method to fix the electrode grid on the blade surface.

[0014] In a preferred embodiment, the high-energy adaptive impedance converter uses a thyristor as an impedance converter. When the electric field strength reaches a threshold, the thyristor is turned on to inject ground charge into the blade electrode. An analog circuit is used to monitor the electric field strength, and the on and off of the thyristor is controlled by a voltage comparator. The high-energy adaptive impedance converter uses voltage triggering. When the electric field strength reaches a threshold, the voltage comparator outputs a high level to trigger the thyristor to turn on. The high-energy adaptive impedance converter uses a varistor to protect the thyristor from overvoltage damage.

[0015] In a preferred embodiment, the grounding wire is a copper wire. The outside of the grounding wire is designed with a polyvinyl chloride insulation layer. The polyvinyl chloride insulation layer has good insulation performance and can effectively prevent the grounding wire from short-circuiting with other components. The grounding wire is crimped to connect the grounding wire to the thyristor and the grounding body. The crimping connection method is simple and reliable, and can ensure the stability of the connection. The grounding body adopts a grounding grid to conduct the charge into the earth. The grounding grid can be buried or overhead, and needs to be selected according to the site environment and geological conditions.

[0016] In a preferred embodiment, the current sensor is responsible for monitoring the magnitude of the ground charge current, thereby determining the strength and distance of the lightning leader. In an active lightning protection device, the function of the current sensor is to monitor the magnitude of the ground charge current in real time by sensing the current in the grounding wire, and transmit the current signal to the microcontroller. The current sensor is mainly composed of a Hall element, an amplifier circuit, a filter circuit, and a signal output circuit. The Hall element is used to sense the current in the grounding wire and convert it into a voltage signal. The amplifier circuit amplifies the weak voltage signal output by the Hall element to a measurable range, and the filter circuit is used to filter out noise and interference signals. The signal output circuit converts the filtered voltage signal into a standard signal output, such as a 0-5V analog signal or a digital signal.

[0017] In a preferred embodiment, the memory is an important component of the active lightning protection device, which is responsible for storing the measurement data of each ground charge current for subsequent analysis and processing. In the active lightning protection device, the role of the memory is to provide historical data support for the system by storing ground charge current data, so as to evaluate and optimize the lightning protection effect.

[0018] In a preferred embodiment, the GPRS module is an important component of the active lightning protection device, which is responsible for transmitting the ground charge current data to the monitoring center in real time. In the active lightning protection device, the function of the GPRS module is to transmit the ground charge current data to the monitoring center in real time through the GPRS network to achieve remote monitoring and maintenance.

[0019] In a preferred embodiment, the server is the core device in the active lightning protection system, which is responsible for receiving and processing data from each module and performing real-time analysis. The server is usually composed of hardware such as a processor, memory, and hard disk, and runs an operating system and application software.

[0020] In a preferred embodiment, the analysis software is an important component of the active lightning protection system, which is responsible for analyzing the data and providing relevant analysis results. In the active lightning protection system, the main function of the analysis software is to analyze the ground charge current data received by the server, evaluate the lightning protection effect, and provide relevant analysis results to the user.

[0021] In a preferred embodiment, a method for using an active lightning protection system is characterized in that the method comprises the following steps:

[0022] Step S1: First, according to the size and location of the wind turbine, select the appropriate wind turbine blade electrode material and shape, and install the electrode on the blade. Then, install the high-energy adaptive impedance transformer and connect the ground wire. Make sure all components are installed correctly and firmly to ensure the normal operation of the system.

[0023] Step S2: Use the microcontroller to configure the parameters of the current sensor, memory and GPRS module to ensure that they can work properly. After the configuration is completed, these modules are connected to the microcontroller and the connectivity and stability of the system are tested.

[0024] Step S3: Power on the system and start the microcontroller. The microcontroller will automatically detect the working status of each module and perform corresponding initialization settings. When the system is successfully started, it can start working.

[0025] Step S4: After the system is started, the current sensor will monitor the magnitude of the ground charge current in real time and transmit the data to the microcontroller. The microcontroller stores the data in the memory and transmits it to the monitoring center in real time through the GPRS module. The monitoring center can receive the ground charge current data in real time and perform real-time analysis.

[0026] Step S5: According to the real-time monitored ground charge current data, the microcontroller will control the working state of the high-energy adaptive impedance converter. When the lightning leader approaches the fan blade electrode, due to the electrostatic induction of the electric field, charges with opposite signs can be gathered on the fan blade electrode and the electrode of the high-energy adaptive impedance converter. At this time, the high-energy adaptive impedance converter is turned on, and the charge is loaded from the ground to the fan blade electrode through the grounding wire. The current value and current duration of the loaded charge are measured by the detection system and stored locally, and transmitted to the center in real time through the GPRS module. The charge amount of this loaded charge can be obtained according to the current value and current duration. As the lightning leader continues to approach the fan blade electrode, the electric field near the fan blade electrode further increases, and the injection of charge weakens the electric field strength at both ends of the high-energy adaptive impedance converter, and the high-energy adaptive impedance converter becomes a high-resistance state. At this time, the charge on the fan blade electrode is close to a single charge.

[0027] Step S6: After receiving the ground charge and current data, the monitoring center analyzes the data through analysis software, evaluates the lightning protection effect, and provides relevant analysis results to the user. The analysis results can be viewed through the user interface, which is convenient for users to understand the operation of the system.

[0028] Step S7: The user can remotely maintain the system through the user interface, such as viewing the system status, adjusting parameter configuration, etc. In addition, the monitoring center can also remotely monitor the operation of the system, discover and handle faults in a timely manner, and ensure stable operation of the system.

[0029] Step S8: Update and optimize the system according to the actual operation and user needs. For example, adjust the parameter configuration according to the data analysis results to improve the lightning protection effect of the system. After the update is completed, restart the system to apply the new configuration and optimization results.

[0030] Step S9: When the system completes the lightning protection task or needs maintenance, the system can be remotely shut down through the user interface or the monitoring center. After shutting down the system, the power supply needs to be disconnected and the relevant data is properly saved to end the entire use process.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. In the present invention, the guiding ideology is to prevent lightning strikes in local areas rather than attracting lightning. It can interact with the "ladder leader" of lightning, and use the ground charge of the device to neutralize the induced charge of the blades in the protected area with the opposite polarity charge at the far end, so that the induced charge binding in the near lightning cloud is reduced and can overflow to the "ladder leader" of lightning in time to neutralize the "ladder leader". The charges in the air have a tendency to be uniform, so that the electric field strength above the protected object does not reach the value of breaking through the air, changing the main discharge channel of lightning, effectively preventing the occurrence of "return discharge" of ground lightning in the protection area, preventing direct lightning from falling in the protection area, and greatly reducing the density of ground lightning in the protected area. As a result, this method has completely changed the concept of traditional wind turbine lightning protection. When applied to the field of wind power, it can effectively reduce the damage to blades and control systems caused by lightning strikes.

[0033] 2. In the present invention, when a thundercloud approaches an active lightning protection device, the magnitude, time, and number of ground charge currents passing through the device are measured, and the amount of charge passing through is calculated to verify that the thundercloud leader is neutralized and the occurrence of "return discharge" of ground lightning in the protection area is effectively prevented, so that no direct lightning strikes fall in the protection area. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the lightning protection principle flow of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Reference Figure 1 ,

[0037] An active lightning protection system, the system comprising: an active lightning protection device, a ground charge neutralization current detection device and a monitoring center;

[0038] The active lightning protection device includes: fan blade electrodes, high-energy adaptive impedance converters, and grounding conductors;

[0039] Active lightning protection devices neutralize the charge in the lightning leader, prevent return discharge, and protect wind turbines from lightning damage;

[0040] The ground charge neutralization current detection device comprises: a current sensor, a memory, and a GPRS module;

[0041] The ground charge neutralization current detection device monitors the magnitude, time and frequency of ground charge current, evaluates the lightning protection effect, and provides remote maintenance function;

[0042] The monitoring center includes: server, database, analysis software, user interface;

[0043] The monitoring center receives and analyzes ground charge current data, evaluates lightning protection effects, and provides remote maintenance functions.

[0044] The fan blade electrode uses copper alloy, which has good conductivity and corrosion resistance, and is low in cost. The fan blade electrode is in the shape of a mesh electrode, which covers the surface of the blade and can effectively sense and neutralize the charge. The fan blade electrode is designed according to the blade size. For a blade with a length of 50 meters, the spacing of the electrode grid can be designed to be 1 meter. The fan blade electrode uses adhesive to fix the electrode grid on the blade surface.

[0045] The high-energy adaptive impedance converter uses thyristor as impedance converter. When the electric field strength reaches the threshold, the thyristor is turned on and the ground charge is injected into the blade electrode. The electric field strength is monitored by analog circuits, and the on and off of the thyristor is controlled by a voltage comparator. The high-energy adaptive impedance converter uses voltage triggering. When the electric field strength reaches the threshold, the voltage comparator outputs a high level, triggering the thyristor to turn on. The high-energy adaptive impedance converter uses varistors to protect the thyristor from overvoltage damage.

[0046] Copper wire is used for grounding wire. The outside of the grounding wire is designed with a polyvinyl chloride insulation layer. The polyvinyl chloride insulation layer has good insulation performance and can effectively prevent the grounding wire from short-circuiting with other components. The grounding wire is crimped to connect the grounding wire to the thyristor and the grounding body. The crimping connection method is simple and reliable, and can ensure the stability of the connection. The grounding body uses a grounding grid to conduct the charge into the earth. The grounding grid can be buried or overhead, and needs to be selected according to the site environment and geological conditions.

[0047] The current sensor is responsible for monitoring the magnitude of the ground charge current, thereby determining the strength and distance of the lightning leader. In an active lightning protection device, the function of the current sensor is to monitor the magnitude of the ground charge current in real time by sensing the current in the grounding conductor, and transmit the current signal to the microcontroller. The current sensor is mainly composed of a Hall element, an amplifier circuit, a filter circuit, and a signal output circuit. The Hall element is used to sense the current in the grounding conductor and convert it into a voltage signal. The amplifier circuit amplifies the weak voltage signal output by the Hall element to a measurable range, and the filter circuit is used to filter out noise and interference signals. The signal output circuit converts the filtered voltage signal into a standard signal output, such as a 0-5V analog signal or a digital signal.

[0048] Through the monitoring of current sensors, active lightning protection devices can grasp the changes in ground charge current in real time, and judge the strength and distance of lightning leaders according to the current size, thereby controlling the working state of high-energy adaptive impedance converters and achieving effective protection against lightning.

[0049] The memory is an important component of the active lightning protection device. It is responsible for storing the measurement data of each ground charge current for subsequent analysis and processing. In the active lightning protection device, the role of the memory is to provide historical data support for the system by storing ground charge current data, so as to evaluate and optimize the lightning protection effect.

[0050] Specifically, the memory is mainly composed of a flash memory chip and an interface circuit. The flash memory chip is responsible for storing ground charge current data, including current size, time, duration and other information. The interface circuit is used to connect the flash memory chip and the microcontroller or other data acquisition device to realize data reading and writing.

[0051] Through the storage of the memory, the active lightning protection device can record the data of each ground charge current, providing data support for the evaluation and optimization of the lightning protection effect of the system. At the same time, the memory can also provide users with historical data query functions, which is convenient for users to understand the operation of the system.

[0052] The GPRS module is an important component of the active lightning protection device. It is responsible for transmitting the ground charge current data to the monitoring center in real time. In the active lightning protection device, the function of the GPRS module is to transmit the ground charge current data to the monitoring center in real time through the GPRS network to achieve remote monitoring and maintenance.

[0053] Specifically, the GPRS module is mainly composed of a GPRS module circuit, a SIM card interface circuit, and a signal output circuit. The GPRS module circuit is responsible for converting the ground charge current data into a GPRS signal and sending it to the monitoring center through the GPRS network. The SIM card interface circuit is used to connect the SIM card and provide the power and signal required by the GPRS module. The signal output circuit converts the signal output by the GPRS module circuit into a standard signal output, such as a TTL signal or an RS232 signal.

[0054] Through the transmission of the GPRS module, the active lightning protection device can realize real-time monitoring and maintenance of ground charge current data. The monitoring center can receive ground charge current data through the GPRS module, conduct real-time analysis, evaluate the lightning protection effect, and provide remote maintenance functions. At the same time, the GPRS module can also provide users with remote monitoring and maintenance functions, which is convenient for users to understand and control the operation of the system in real time.

[0055] The server is the core device in the active lightning protection system. It is responsible for receiving and processing data from various modules and performing real-time analysis. The server is usually composed of hardware such as processors, memory, hard disks, and runs operating systems and application software.

[0056] In the active lightning protection system, the main function of the server is to receive data from the current sensor, memory and GPRS module and perform real-time analysis. By analyzing this data, the server can evaluate the lightning protection effect and provide users with real-time monitoring and maintenance functions.

[0057] The server usually uses high-performance hardware configuration to ensure that it can process large amounts of data and provide fast response speed. In addition, the server also needs to have good stability and reliability to ensure the stable operation of the system.

[0058] The database is an important part of the active lightning protection system, which is responsible for storing and managing various data. In the active lightning protection system, the main function of the database is to store ground charge and current data and provide users with data query and analysis functions.

[0059] Specifically, the database is mainly composed of a database management system (DBMS) and a storage medium. The database management system is responsible for the storage, management and query of data, while the storage medium is responsible for the storage of data.

[0060] Through the storage and management of the database, the active lightning protection system can record and analyze a large amount of ground charge and current data, providing data support for the evaluation and optimization of the lightning protection effect of the system. At the same time, the database can also provide users with data query and analysis functions, making it easier for users to understand the operation of the system.

[0061] Analysis software is an important part of the active lightning protection system. It is responsible for analyzing data and providing relevant analysis results. In the active lightning protection system, the main function of the analysis software is to analyze the ground charge current data received by the server, evaluate the lightning protection effect, and provide users with relevant analysis results.

[0062] Specifically, the analysis software usually consists of a data processing module, an analysis and reporting module, etc. The data processing module is responsible for preprocessing the data, including data cleaning, conversion, and formatting. The analysis and reporting module is responsible for analyzing the data and providing relevant analysis results, such as the strength and distance of the lightning leader, and the evaluation of the lightning protection effect.

[0063] Through the analysis of the analysis software, the active lightning protection system can conduct in-depth analysis of the ground charge and current data, providing data support for the evaluation and optimization of the lightning protection effect of the system. At the same time, the analysis software can also provide users with relevant analysis results to facilitate users to understand the operation of the system;

[0064] The user interface is an important part of the active lightning protection system. It is responsible for providing an interface for users to interact with the system. In the active lightning protection system, the main function of the user interface is to provide users with the function of viewing ground charge current data and system status, and to perform remote management.

[0065] Specifically, the user interface usually consists of a graphical user interface (GUI) and a command line interface (CLI). The graphical user interface provides an intuitive interface for users to view ground charge current data and system status. The command line interface provides command line operations for users to perform remote management.

[0066] Through the interaction of the user interface, the active lightning protection system can facilitate users to view ground charge current data and system status, and perform remote management. The user interface can also provide users with data query and analysis functions, making it easier for users to understand the operation of the system.

[0067] The method of use includes the following steps:

[0068] Step S1: First, according to the size and location of the wind turbine, select the appropriate wind turbine blade electrode material and shape, and install the electrode on the blade. Then, install the high-energy adaptive impedance transformer and connect the ground wire. Make sure all components are installed correctly and firmly to ensure the normal operation of the system.

[0069] Step S2: Use the microcontroller to configure the parameters of the current sensor, memory and GPRS module to ensure that they can work properly. After the configuration is completed, these modules are connected to the microcontroller and the connectivity and stability of the system are tested.

[0070] Step S3: Power on the system and start the microcontroller. The microcontroller will automatically detect the working status of each module and perform corresponding initialization settings. When the system is successfully started, it can start working.

[0071] Step S4: After the system is started, the current sensor will monitor the size of the ground charge current in real time and transmit the data to the microcontroller. The microcontroller stores the data in the memory and transmits it to the monitoring center in real time through the GPRS module. The monitoring center can receive the ground charge current data in real time and perform real-time analysis.

[0072] Step S5: According to the real-time monitored ground charge current data, the microcontroller will control the working state of the high-energy adaptive impedance converter. When the lightning leader approaches the fan blade electrode, due to the electrostatic induction of the electric field, charges with opposite signs can be gathered on the fan blade electrode and the electrode of the high-energy adaptive impedance converter. At this time, the high-energy adaptive impedance converter is turned on, and the charge is loaded from the ground to the fan blade electrode through the grounding wire. The current value and current duration of the loaded charge are measured by the detection system and stored locally, and transmitted to the center in real time through the GPRS module. The charge amount of this loaded charge can be obtained according to the current value and current duration. As the lightning leader continues to approach the fan blade electrode, the electric field near the fan blade electrode further increases, and the injection of charge weakens the electric field strength at both ends of the high-energy adaptive impedance converter, and the high-energy adaptive impedance converter becomes a high-resistance state. At this time, the charge on the fan blade electrode is close to a single charge.

[0073] Step S6: After receiving the ground charge and current data, the monitoring center analyzes the data through analysis software, evaluates the lightning protection effect, and provides relevant analysis results to the user. The analysis results can be viewed through the user interface, which is convenient for users to understand the operation of the system.

[0074] Step S7: The user can remotely maintain the system through the user interface, such as viewing the system status, adjusting parameter configuration, etc. In addition, the monitoring center can also remotely monitor the operation of the system, discover and handle faults in a timely manner, and ensure stable operation of the system.

[0075] Step S8: Update and optimize the system according to the actual operation and user needs. For example, adjust the parameter configuration according to the data analysis results to improve the lightning protection effect of the system. After the update is completed, restart the system to apply the new configuration and optimization results.

[0076] Step S9: When the system completes the lightning protection task or needs maintenance, the system can be remotely shut down through the user interface or the monitoring center. After shutting down the system, the power supply needs to be disconnected and the relevant data is properly saved to end the entire use process.

[0077] The working principle of the present invention to realize lightning protection is:

[0078] ①. The first stage: the charge accumulation stage. As the lightning leader develops downward and approaches the fan blade electrode, due to the electrostatic induction of the electric field, charges with opposite signs can be accumulated on the fan blade electrode and the electrode of the high-energy adaptive impedance converter. At this time, Ks is less than Kc, the high-energy adaptive impedance converter is in a high-resistance state, and the fan blade electrode can be regarded as insulated from the ground.

[0079] ②. The second stage: the charge loading stage. The lightning leader further develops to make Ks greater than Kc (3Kv~5Kv / cm). At this time, the high-energy adaptive impedance converter is turned on, and the charge is loaded from the ground to the wind turbine blade electrode through the grounding wire. The current value and current duration of the loaded charge are measured by the detection system and stored locally. At the same time, they are transmitted to the center in real time through the GPRS module. The charge amount of this loaded charge can be obtained based on the current value and current duration.

[0080] ③. The third stage: blocking state As the lightning leader continues to approach the fan blade electrode, the electric field near the fan blade electrode further increases, and the injection of charge weakens the electric field strength at both ends of the high-energy adaptive impedance converter. When Ks is less than Kc, the high-energy adaptive impedance converter changes to a high-impedance state. At this time, the charge on the fan blade electrode is close to a single charge.

[0081] ④. The fourth stage: the charge overflow neutralization stage. Since the lightning leader is always near the fan blade electrode, the electric field strength Ke near the fan blade electrode continues to increase. When it reaches a value close to Kcs, corona discharge is generated above the fan blade electrode. Ke continues to increase. When Ke≥Kcs, if a conventional lightning rod is used, "return discharge" occurs and the lightning leader turns into a lightning strike. However, since the high-energy adaptive impedance converter is in a high-resistance state, the "return discharge" current path is blocked under its action. Only the loaded charge on the blade overflows upward due to the thundercloud electric field. This charge overflow faces the downward direction of the lightning leader, and its sign is opposite to that of the lightning leader. It neutralizes the lightning current and suppresses the occurrence of "return discharge".

[0082] ⑤. The fifth stage: the cycle stage After the charge overflowed and neutralized in the previous stage, if the charge in the lightning leader is not completely neutralized, Ks will increase again, and the active lightning protection device will start the aforementioned working cycle again. Therefore, the active lightning protection device returns to its original state after each protective intervention, ready for the next intervention. The shortest time for the impedance converter to open / close is in milliseconds, and the number of interventions is related to the coulomb number of the thundercloud leader charge until the thundercloud leader is eliminated. The detection system records the value and number of each loaded charge to obtain the loaded charge value that completely eliminates the lightning leader.

[0083] Among them: The lightning protection technology of active lightning protection device is guided by the idea of ​​preventing lightning in local areas rather than attracting lightning. It can interact with the "ladder leader" of lightning, and timely overflow the induced charge on the surface of the protected area to the "ladder leader" of lightning, reduce the charge density on the surface of the protected object, and neutralize the "ladder leader". The charge in the air has a tendency to be uniform, so that the electric field strength above the protected object does not reach the value of breaking through the air, changing the main discharge channel of lightning, effectively preventing the occurrence of "return discharge" of ground lightning in the protection area, so that there is no direct lightning in the protection area, and greatly reducing the density of ground lightning in the protected area.

[0084] In order to explain the physical principle of the active lightning protection device, the following symbols and meanings are set:

[0085] Ke: electric field strength near the fan blade electrode;

[0086] Ks: Electric field strength between the two poles of the high energy adaptive impedance converter;

[0087] Kc: The electric field strength value corresponding to the on-state of the high-energy adaptive impedance converter;

[0088] Kcs: The critical value of the electric field required to form an upward lightning strike.

[0089] From this, we can know that: in the present invention, the guiding ideology is to prevent lightning strikes in local areas rather than attracting lightning. It can interact with the "ladder leader" of lightning, and use the ground charge of the device to neutralize the induced charge of the blades in the protected area with the opposite polarity charge at the far end, so that the induced charge binding in the near lightning cloud is reduced and can overflow to the "ladder leader" of lightning in time to neutralize the "ladder leader". The charges in the air have a tendency to be uniform, so that the electric field strength above the protected object does not reach the value of breaking through the air, changing the main discharge channel of lightning, effectively preventing the occurrence of "return discharge" of ground lightning in the protection area, preventing direct lightning from falling in the protection area, and greatly reducing the density of ground lightning in the protected area. As a result, this method has completely changed the concept of traditional wind turbine lightning protection. When applied to the field of wind power, it can effectively reduce the damage to blades and control systems caused by lightning strikes.

[0090] In the present invention, when a thundercloud approaches an active lightning protection device, the magnitude, time, and number of ground charge currents passing through the device are measured, and the amount of charge passing through is calculated to verify that the thundercloud leader is neutralized and the occurrence of "return discharge" of ground lightning in the protection area is effectively prevented, so that no direct lightning strikes fall in the protection area.

[0091] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An active lightning protection system, characterized in that: The system includes: an active lightning protection device, a ground charge neutralization current detection device and a monitoring center; The active lightning protection device comprises: a fan blade electrode, a high-energy adaptive impedance converter, and a grounding conductor; The active lightning protection device neutralizes the charge in the lightning leader to prevent the occurrence of return discharge, thereby protecting the wind turbine from damage caused by lightning. The ground charge neutralization current detection device comprises: a current sensor, a memory, and a GPRS module; The ground charge neutralization current detection device monitors the magnitude, time and frequency of ground charge current, evaluates the lightning protection effect, and provides remote maintenance function; The monitoring center includes: a server, a database, analysis software, and a user interface; The monitoring center receives and analyzes ground charge current data, evaluates lightning protection effects, and provides remote maintenance functions.

2. An active lightning protection system as claimed in claim 1, characterized in that: The fan blade electrode uses copper alloy, and the fan blade electrode is in the shape of a mesh electrode, covering the blade surface. The fan blade electrode is designed according to the blade size. For a blade with a length of 50 meters, the spacing of the electrode grid is designed to be 1 meter; the fan blade electrode uses an adhesive method to fix the electrode grid to the blade surface.

3. An active lightning protection system as claimed in claim 1, characterized in that: The high-energy adaptive impedance converter uses a thyristor as an impedance converter. When the electric field intensity reaches a threshold, the thyristor is turned on to inject ground charges into the blade electrode. An analog circuit is used to monitor the electric field strength, and a voltage comparator is used to control the conduction and disconnection of the thyristor; the high-energy adaptive impedance converter is voltage-triggered, and when the electric field strength reaches a threshold, the voltage comparator outputs a high level to trigger the thyristor to conduct; the high-energy adaptive impedance converter uses a varistor to protect the thyristor from overvoltage damage.

4. An active lightning protection system according to claim 1, characterized in that: The grounding wire is a copper wire; the outside of the grounding wire is designed with a polyvinyl chloride insulation layer; The polyvinyl chloride insulation layer has good insulation performance and can effectively prevent the grounding wire from short-circuiting with other components; the grounding wire adopts a crimping method to connect the grounding wire to the thyristor and the grounding body; the crimping connection method is simple and reliable, and can ensure the stability of the connection; the grounding body adopts a grounding grid to conduct the charge into the earth; the grounding grid adopts buried or overhead type, which needs to be selected according to the site environment and geological conditions.

5. An active lightning protection system as claimed in claim 1, characterized in that: The current sensor is responsible for monitoring the magnitude of the ground charge current, thereby determining the strength and distance of the lightning leader; in an active lightning protection device, the function of the current sensor is to monitor the magnitude of the ground charge current in real time by sensing the current in the grounding conductor, and transmit the current signal to the microcontroller; the current sensor is mainly composed of a Hall element, an amplifying circuit, a filtering circuit, and a signal output circuit; the Hall element is used to sense the current in the grounding conductor and convert it into a voltage signal; Through the monitoring of the current sensor, the active lightning protection device grasps the changes in the ground charge current in real time, and judges the strength and distance of the lightning leader according to the current size, thereby controlling the working state of the high-energy adaptive impedance converter and achieving effective protection against lightning.

6. An active lightning protection system according to claim 1, characterized in that: The memory is an important component of the active lightning protection device, which is responsible for storing the measurement data of each ground charge current for subsequent analysis and processing; in the active lightning protection device, the role of the memory is to provide historical data support for the system by storing ground charge current data, so as to evaluate and optimize the lightning protection effect; Specifically, the memory is mainly composed of a flash memory chip and an interface circuit; the flash memory chip is responsible for storing ground charge current data, including current size, time, and duration information; the interface circuit is used to connect the flash memory chip and a microcontroller or other data acquisition device to realize data reading and writing; Through the storage of the memory, the active lightning protection device records the data of each ground charge current, providing data support for the evaluation and optimization of the lightning protection effect of the system; at the same time, the memory also provides users with historical data query function, which is convenient for users to understand the operation of the system.

7. An active lightning protection system according to claim 1, characterized in that: The GPRS module transmits the ground charge current data to the monitoring center in real time; in the active lightning protection device, the function of the GPRS module is to transmit the ground charge current data to the monitoring center in real time through the GPRS network to realize remote monitoring and maintenance; the GPRS module is mainly composed of a GPRS module circuit, a SIM card interface circuit and a signal output circuit; the GPRS module circuit is responsible for converting the ground charge current data into a GPRS signal and sending it to the monitoring center through the GPRS network; the SIM card interface circuit is used to connect the SIM card and provide the power and signal required by the GPRS module.

8. An active lightning protection system as claimed in claim 1, characterized in that: The server is responsible for receiving and processing data from each module and performing real-time analysis; the server is composed of a processor, memory, and hard disk hardware, and runs an operating system and application software; in the active lightning protection system, the main function of the server is to receive data from current sensors, memory, and GPRS modules, and perform real-time analysis; by analyzing these data, the server evaluates the lightning protection effect and provides users with real-time monitoring and maintenance functions; the server uses high-performance hardware configuration to ensure that it can process large amounts of data and provide a fast response speed; in addition, the server also needs to have good stability and reliability to ensure the stable operation of the system; The database is responsible for storing and managing various data; in the active lightning protection system, the main function of the database is to store ground charge current data and provide users with data query and analysis functions; the database is mainly composed of a database management system (DBMS) and a storage medium; the database management system is responsible for the storage, management and query of data, while the storage medium is responsible for the storage of data; through the storage and management of the database, the active lightning protection system records and analyzes a large amount of ground charge current data, providing data support for the evaluation and optimization of the lightning protection effect of the system; at the same time, the database also provides users with data query and analysis functions, making it convenient for users to understand the operation of the system.

9. An active lightning protection system as claimed in claim 1, characterized in that: The analysis software is an important part of the active lightning protection system. It is responsible for analyzing the data and providing relevant analysis results. In the active lightning protection system, the main function of the analysis software is to analyze the ground charge current data received by the server, evaluate the lightning protection effect, and provide relevant analysis results to the user. The user interface is an important component of the active lightning protection system, which is responsible for providing an interface for users to interact with the system. In the active lightning protection system, the main function of the user interface is to provide users with the function of viewing ground charge current data and system status, and performing remote management.

10. The method for using the active lightning protection system according to claim 1, characterized in that: The method of use comprises the following steps: Step S1: First, according to the size and location of the wind turbine, select the appropriate material and shape of the wind turbine blade electrode, and install the electrode on the blade; then, install the high-energy adaptive impedance converter and connect the grounding wire; ensure that all components are installed correctly and firmly to ensure the normal operation of the system; Step S2: Use the microcontroller to configure the parameters of the current sensor, memory and GPRS module to ensure that they can work normally; after the configuration is completed, connect these modules to the microcontroller and test the connectivity and stability of the system; Step S3: Power on the system and start the microcontroller; the microcontroller will automatically detect the working status of each module and perform corresponding initialization settings; when the system is successfully started, it can start working; Step S4: After the system is started, the current sensor will monitor the size of the ground charge current in real time and transmit the data to the microcontroller; the microcontroller stores the data in the memory and transmits it to the monitoring center in real time through the GPRS module; the monitoring center receives the ground charge current data in real time and performs real-time analysis; Step S5: According to the real-time monitored ground charge current data, the microcontroller will control the working state of the high-energy adaptive impedance converter; when the lightning leader approaches the fan blade electrode, due to the electrostatic induction of the electric field, charges with opposite signs are gathered on the fan blade electrode and the electrode of the high-energy adaptive impedance converter; at this time, the high-energy adaptive impedance converter is turned on, and charges are loaded from the ground to the fan blade electrode through the grounding wire. The current value and current duration of the loaded charge are measured by the detection system and stored locally, and transmitted to the center in real time through the GPRS module. The charge amount of this loaded charge can be obtained according to the current value and current duration; as the lightning leader continues to approach the fan blade electrode, the electric field near the fan blade electrode further increases, and the injection of charge weakens the electric field strength at both ends of the high-energy adaptive impedance converter, and the high-energy adaptive impedance converter becomes a high-resistance state; at this time, the charge on the fan blade electrode is close to a single charge; Step S6: After receiving the ground charge and current data, the monitoring center analyzes the data through analysis software, evaluates the lightning protection effect, and provides relevant analysis results to the user; the analysis results are viewed through the user interface, so that the user can understand the operation of the system; Step S7: The user performs remote maintenance on the system through the user interface, including checking the system status and adjusting parameter configurations; in addition, the monitoring center also remotely monitors the operation of the system, discovers and handles faults in a timely manner, and ensures stable operation of the system; Step S8: Update and optimize the system according to the actual operation situation and user needs; adjust the parameter configuration according to the data analysis results to improve the lightning protection effect of the system; after the update is completed, restart the system to apply the new configuration and optimization results; Step S9: When the system completes the lightning protection task or needs maintenance, the system is remotely shut down through the user interface or the monitoring center; after shutting down the system, the power supply needs to be disconnected and the relevant data needs to be properly saved to end the entire use process.

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