Patent Application
20250141218
The present invention belongs to the field of lightning protection for power transmission lines, and discloses a method, apparatus and system for limiting lightning overvoltage of a direct-current power transmission line, and a recording medium storing a program capable of executing the method.
In recent years, direct-current (DC) transmission has developed rapidly in China. Lightning stroke has always been the primary cause of fault restart of DC transmission lines, accounting for about 50-60%, and the lightning-induced restart rate far exceeds the design and operation requirements. Against this background, China has developed ±400 kV-±1100 kV DC line lightning arresters to limit the lightning overvoltage of lines, and engineering applications have been realized, resulting in a certain degree of improvement in the lightning-induced restart rate of the lines.
DC transmission lines cover long distances, traversing complex environments with varying terrain, landforms, and climates. Currently, the lightning protection performance of the entire line is designed and calculated according to uniform standard procedures, without considering the impulse of different regions and environmental changes of the regions on the lightning protection performance parameters. The selection and design of line lightning arresters are solely based on lightning parameters, without considering the impact of the operating voltage of the line, which can lead to frequent actuation of the developed lightning arresters and reduced service life. Additionally, DC line lightning arresters adopt a pure air-clearance structure and are exposed to the atmospheric environment, thus being highly affected by the factors of altitude and climate. Therefore, multiple performance tests and verifications need to be conducted for lightning arresters used in different environments. Under conditions such as strong winds and heavy rains, when the line is struck by lightning, the lightning arrester may fail to actuate or malfunction. Moreover, these lightning arresters do not possess the function of monitoring their own status.
Aiming at the above problems, the present invention provides a method for limiting lightning overvoltage of a DC transmission line, including the following steps:
S1, acquiring static operation data of the DC transmission line and lightning current monitoring data of the line subjected to lightning strike through a monitoring instrument, wherein the static operation data includes voltage and current of the line not subjected to lightning strike, and the lightning current monitoring data includes lightning current amplitude, lightning current waveform and lightning strike time; superimposing the impact of the lightning current monitoring data on line operation onto the static operation data by electromagnetic transient simulation software to form dynamic operation data including voltage and current values; and establishing a coordinate system with time as a horizontal axis and the voltage of the dynamic operation data as a vertical axis to draw a line dynamic operation function curve;
S2, correcting lightning protection performance parameters of the DC power transmission line in real time according to environmental factor data, wherein the lightning protection performance parameters include an air clearance of a tower head at a line tower and a lightning impulse discharge voltage of a line insulator, and the environmental factor data includes topography, landforms, temperature, humidity, contamination level and air pressure values in the environment where the line is located; and establishing a coordinate system with time as the horizontal axis and the lightning impulse discharge voltage as the vertical axis to draw a line lightning protection performance function curve; and
S3, subtracting a voltage value on the line dynamic operation function curve from a voltage value on the line lightning protection performance function curve at any moment in the same coordinate system to obtain a voltage difference, and a lightning arrester arranged in the line activating discharge protection and recording discharge data of the lightning arrester when the voltage difference is less than 15%-20% of dynamic operating voltage at the moment.
Preferably, the lightning arrester includes a body unit and a clearance unit that are connected in sequence, wherein a sensing module is arranged in the body unit, and gas located between electrodes at both ends of a clearance in the clearance unit is sealed by an insulating material.
Preferably, line sections affected by lightning strike are sequentially divided into a safe area, a disturbance area and a hazardous area according to a spacing between the line dynamic operation function curve and the line lightning protection performance function curve at different positions from a lightning strike point, and a DC line lightning arrester is installed and arranged in the hazardous area.
Preferably, one end of the clearance unit of the lightning arrester is fixed to the line, and one end of the body unit is fixed to a tower cross arm above the line or to a tower below the line.
In order to cooperate with the above method for implementation, based on the same inventive idea, the present invention also provides an apparatus for limiting lightning overvoltage of a DC transmission line, including the following functional modules:
Preferably, the lightning arrester includes a body unit and a clearance unit that are connected in sequence, wherein a sensing module is arranged in the body unit, and gas located between electrodes at both ends of a clearance in the clearance unit is sealed by an insulating material.
Preferably, line sections affected by lightning strike are sequentially divided into a safe area, a disturbance area and a hazardous area according to a spacing between the line dynamic operation function curve and the line lightning protection performance function curve at different positions from a lightning strike point, and the lightning arrester is only arranged in the hazardous area.
Preferably, one end of the clearance unit of the lightning arrester is fixed to the line, and one end of the body unit is fixed to a tower cross arm above the line or to a tower below the line.
Another solution of the present invention is to provide a non-transient readable recording medium for storing one or more programs including a plurality of instructions, wherein the instructions, when being executed, cause a processing circuit to perform the method for limiting lightning overvoltage of a DC power transmission line as described above.
The present invention also provides a system for limiting lightning overvoltage of a DC transmission line, including a processing circuit, and a memory electrically coupled the processing circuit, wherein the memory is configured to store at least one program including a plurality of instructions, and the processing circuit runs the program to perform the method for limiting lightning overvoltage of a DC power transmission line.
The present invention has the beneficial effects that:
1. Improvement in the operation and action reliability of the lightning arrester. The impact of static operation data on dynamic operation data of the DC transmission line subjected to lightning strike is fully considered, the line dynamic operation function curve is fitted, the design principle of the lightning impulse discharge voltage of the lightning arrester is optimized, the operation and action reliability of the lightning arrester is improved, and the distribution law of line overvoltage after lightning strike is mastered, which provides a basis for the division of line sections affected by lightning strike and the selection of lightning arrester installation points.
2. Mastering of real-time lightning protection parameters of lines in different environments. The lightning protection performance parameters of the DC transmission line are corrected in real time based on the topography, landforms, temperature, humidity, contamination level and air pressure values in the environment where the line is located, the line lightning protection performance function curve is fitted, the voltage difference is calculated in real time in combination with the line dynamic operation function curve, and the action state of the lightning arrester is evaluated.
3. Reduction in the testing workload and design difficulty of the lightning arrester. The clearance structure of the lightning arrester is enclosed within a confined space, and is not affected by altitude and climate factors, allowing convenient testing in low-altitude environments. After passing the test, the lightning arrester can be directly applied to various altitude regions, thus reducing the design and manufacturing difficulty of the lightning arrester, improving the universality of the lightning arrester, and avoiding unprotected or malfunctions when the lightning arrester is subjected to lightning strike under severe weather conditions such as strong winds and heavy rains.
4. Realization of visualization of the state of the lightning arrester. The changes in various state parameters before and after the lightning arrester is subjected to lightning strike are recorded, the real-time operating state of the lightning arrester is sensed, and the action characteristics of the lightning arrester are evaluated, which provides support for the life prediction and intelligent operation and maintenance of the lightning arrester.
wherein: 1—body unit; 2—clearance unit; 3—tower; 4—cross arm; 5—DC transmission line; 6—transmission line insulator; 1-1—data acquisition module; 1-2—environmental monitoring module; 1-3—data processing module; 1-4—sensing module; 2-1—upper electrode; 2-2—insulating support; 2-3—insulating sealing sleeve; and 2-4—lower electrode.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be described below in conjunction with the accompanying drawings of the embodiments of the present invention, the described embodiments are some, but not all, of the embodiments of the present invention. On basis of the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making inventive labor belong to the protection scope of the present invention.
As shown in
The apparatus further includes a lightning arrester in communication connection with the sensing module 1-4, and fixed between a DC transmission line 5 and a tower 3, the lightning arrester includes body units 1 and clearance units 2 that are connected in sequence, the sensing module 1-4 is located in the body unit 1, gas located between electrodes at both ends of a clearance in the clearance unit 2 is sealed by an insulating sealing sleeve 2-3, the insulating sealing sleeve is internally provided with an upper electrode 2-1, an insulating support 2-2 and a lower electrode 2-4, the upper electrode 2-1 and the lower electrode 2-4 are both fixedly mounted on the insulating support 2-2, and the clearance distance between the upper electrode 2-1 and the lower electrode 2-4 can be determined according to the requirements of lightning arresters with different voltage levels for lightning impulse discharge voltage and DC withstand voltage, or can be achieved by filling the interior with gases having different conductive properties. The line sections affected by lightning strike are sequentially divided into a safe area, a disturbance area and a hazardous area according to the spacing between the line dynamic operation function curve and the line lightning protection performance function curve at different positions from a lightning strike point, and the lightning arrester is only arranged in the hazardous area. One end of the clearance unit 2 of the lightning arrester is fixed to the line, the body unit 1 and the clearance unit 2 of the lightning arrester are rigidly connected, and one end of the body unit 1 is fixed to a tower cross arm 4 above the line, so that the function of the lightning arrester replacing the original right line insulator as a whole can be achieved; the body unit 1 and the clearance unit 2 of the lightning arrester can also be flexibly connected to form a lightning arrester similar to an AC line insulator support clearance lightning arrester, and one end of the body unit 1 is fixed to a tower below the line, which enables the first application of this installation method to DC power lines.
The detailed manner of calculating the functions in the module and the detailed operation method after the device of this embodiment is put into service is described in the following example of a method for limiting lightning overvoltage of a DC transmission line:
The main technical parameters of the extra high voltage DC transmission line lightning arrester selected in this embodiment are as follows:
As shown in
Specifically, as shown in
Lightning protection performance parameters of the DC power transmission line are corrected in real time according to the environmental factor data, wherein the lightning protection performance parameters include an air clearance of a tower head at a line tower and a lightning impulse discharge voltage of a line insulator, and the environmental factor data includes topography, landforms, temperature, humidity, contamination level and air pressure values in the environment where the line is located; a coordinate system is established with time as the horizontal axis and the lightning impulse discharge voltage as the vertical axis to draw the line lightning protection performance function curve (see
The line dynamic operation function curve and the line lightning protection performance function curve are integrated into the same coordinate system, a voltage value on the line dynamic operation function curve is subtracted from a voltage value on the line lightning protection performance function curve to obtain a voltage difference, when the voltage difference is less than 15%-20% of the dynamic operating voltage at that moment, see
It should be understood by those skilled in the art that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can adopt embodiments taking the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention can take the form of a computer program product implemented on one or more computers and available storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) in which computer usable program codes are embodied.
The present invention is described with reference to flowcharts and/or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each flow and/or block in the flowchart and/or block diagram, and combinations of the flow and/or block in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor or other programmable data processing device to produce a machine, such that the instructions which are executed by the processor of the computer or other programmable data processing device produce an apparatus for implementing the functions specified in one or more flows of the flowchart and/or one or more blocks of the block diagram.
These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction apparatuses that implement the functions specified in one or more flows of the flowchart and/or one or more blocks of the block diagram.
These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce computer-implemented processing, such that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows of the flowchart and/or one or more blocks of the block diagram.
Compiling the above method steps into a program and then storing the program in a hard disk or other non-transient storage media constitute an embodiment of the non-transient readable recording medium of the present invention; the storage medium is electrically connected to the computer processor, and the limitation of overvoltage of the line subjected to lightning strike can be completed through data processing, which constitutes the embodiment of the “system for limiting lightning overvoltage of a DC transmission line” of the present invention.
Finally, it should be explained that the above embodiments are only the preferred embodiments of the present invention, and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it is still possible for a person skilled in the art to modify the technical solution described in the foregoing embodiments or to equivalent replace some technical features. Any modification, equivalent substitution, improvement, and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202211648056.9 | Dec 2022 | CN | national |
This application is a continuation of International Patent Application No. PCT/CN2022/141786 with an international filing date of Dec. 26, 2022, designating the United States, now pending, and further claims foreign priority benefits to Chinese Patent Application No. 202211648056.9 filed on Dec. 21, 2022. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2022/141786 | Dec 2022 | WO |
| Child | 19004444 | US |
