High voltage power line lightning rod

High voltage power line lightning rod

Ⅰ.Overview of Product Principles and Applications

1.Product structure and working principle

High voltage power line lightning rod (model: LSD-XHGX) is a new type of power line protection equipment, which consists of the following components:

a- stainless tell air terminal、b- Line type resistor (wave resistance device)、 c-fasten bracket（steel material S235JR）、d-grounding down conductor、e-s pecialized lightning strike counting (optional), etc.

Working principle of lightning rod for high-voltage power lines: Direct lightning strikes are introduced into the self dissipating circuit oscillation through the internal self dissipating circuit system device of the line type resistor (wave resistance device) component, while partially consuming lightning energy in the form of capacitor gap discharge, Thereby softening the instantaneous peak value of lightning current, reducing the amplitude and steepness of lightning current, guiding the discharge of lightning energy into the ground while avoiding the generation of large step voltages, effectively preventing line winding and counterattacks, thereby reducing the risk of tripping of protected high-voltage transmission lines due to lightning strikes, and ensuring the safe, reliable, and stable operation of smart grids.

2.Analysis of Product Safety, Efficiency, and Cost in Use

In view of the special and complex geographical location and environmental conditions of high-voltage power line towers, as well as the characteristics of multiple points, wide coverage, and long lines of power line towers, at the same time, considering the uncertainty of lightning protection factors for power line towers, the increasing number of lightning activities year by year, and the increasing risk of lightning strikes on transmission lines, based on the distribution characteristics of power grid minefields, lightning risk assessment, and operational experience, the installation of high-voltage power line lightning rods is a fundamental guarantee measure for the safe operation of the power grid for towers located on special terrains such as mountaintops, slopes, and mountain passes, as well as for towers with large spans, large spans, and high ground wire heights. In the actual operational experience of completing the project, the installation of this lightning rod product on the line tower has a more significant protective effect

 

By installing high-voltage power line lightning rods, the product effectively guides the release of direct lightning energy, softens the lightning current, prevents line winding and counterattacks, effectively reduces the lightning tripping rate of the line, reduces the risk and hidden dangers of line operation, thereby ensuring the safety, stability and operational reliability of the transmission line, and achieving stable operation of the smart grid.

 

According to previous case studies and research, after installing lightning protection products for high-voltage power lines, there will still be no counterattack when a lightning current with an amplitude of 300kA strikes the tower directly. And the lightning rod structure of high-voltage power lines is simple and lightweight, with a total weight of no more than 20kg. It has the technical conditions for live installation and can be easily applied to towers in complex terrains such as mountains and hills, without the need for regular replacement and maintenance. At a lower cost, it can effectively achieve a significant reduction in the lightning trip rate of the transmission line, ensuring the safe and stable operation of the entire line.

3.Product Structure and Model

 

The product structure of lightning rods for high-voltage power lines is shown in Figure 1:

Figure 1: Schematic diagram of the structure of high-voltage power line lightning rod (model: LSD-XHGX)

 

The lightning rod for high-voltage power lines (model: LSD-XHGX) varies according to the voltage level of different transmission lines, as shown in the table below:

Ⅰ. Main technical parameters, advantages, and performance characteristics of the product

1. High voltage power line lightning rod body:

It consists of a - stainless steel lightning rod body, b - line type current resistor (wave resistance device), c - fastening bracket (steel material Q235), d - grounding down conductor, e - dedicated lightning strike counter (optional), etc. When the product leaves the factory, the surface of the complete set of products should be clean and free of dents, scratches, and deformations. The overall assembly position of the components and parts should be firm, without virtual soldering, cracking, or mechanical damage.

In the state where the surge current test device is not connected to the circuit, a surge current of 4/10 μ s with an amplitude of 10kA to 120kA is generated by charging the surge current test device; Then, under the same circuit conditions, connect the high-voltage power line lightning rod to the test circuit and charge it to the same charging voltage as mentioned above. Compare the amplitude and steepness of the impulse current before and after the high-voltage power line lightning rod is connected. After connecting the lightning rod of the high-voltage power line, the amplitude of the impulse current should be reduced by no less than 40%, and the steepness should be reduced by no less than 100%.

2.Product performance advantages

1) Suitable for transmission lines of various voltage levels;

2) Small size, light weight, easy to install on towers;

3) High protection performance, can effectively reduce lightning current amplitude by more than 40%, reduce steepness by more than 100%. Compared with conventional lightning rods (not suitable for installation on 220kV and below voltage level transmission lines with low lightning resistance), it is suitable for installation on ultra-high voltage and below AC/DC transmission lines, with a wider coverage range;

4)Even in the event of a malfunction, it does not affect the normal, safe, and reliable power transmission of high-voltage transmission lines

5)The product is maintenance free and can significantly improve the lightning resistance level of high-voltage transmission lines, reducing the lightning flashover rate of the lines.

3.Calculation of Product Protection Scope

 

The lightning rod of high-voltage power lines has sufficient protection range, and its protection characteristics are shown in Figure 2:

Figure 2 Schematic diagram of the protection range of a single high-voltage power line lightning rod

 

As shown in the figure, when the effective installation height h of the high-voltage power line lightning rod (model: LSD-XHGX) is reached, its ground protection radius r (m) is:

r=2.14h

In the formula: h is the installation height of the controllable needle (m)

On the required height hx (m) plane of the protected object, the protection radius rx (m) is:

r_x=2.14（h—h_x）

4.Product usage conditions

1) Meet the condition of tower grounding resistance R ≤ 30 Ω.

2) Lightning current amplitude I ≤ 350KA

3) Environmental temperature: maximum environmental temperature+50 ℃; Minimum ambient temperature: -50 ℃; Annual average temperature: 20 ℃, maximum daily temperature difference: 30 ℃.

4)Maximum wind speed: 45m/s (once every 15 years at a height of 15 meters above the ground, average maximum value in 10 minutes) Maximum ice thickness: 20mm.

5)Altitude:<6000 meters.

6)Seismic resistance: ≤ level 10.

7)Horizontal acceleration: 0.2g  Vertical acceleration: 0.1g, horizontal and vertical acceleration acting simultaneously and considering the influence of tension oscillation of connecting wires. Sine wave duration: 5 cycles.

8) Safety factor: ≥ 1.87

9) Pollution level 3

10) Thunderstorm days: 90 days/year

11) Maximum monthly average relative humidity: 90%.

Note: The above are general usage conditions. In other special environmental situations, the manufacturer should optimize the parameters or adjust the structure of the product.

5)Installation

1) Principles for selecting installation location

Based on the lightning risk assessment results, when determining the high-risk towers for lightning strikes, attention should be paid to towers that are prone to lightning strikes at higher locations such as mountain tops and slopes, as well as towers that have been struck by lightning and towers near the base.

2)Installation method

This product should generally be installed at the highest point of the tower; The needle tip should be at least 2 meters higher than the highest point of the iron tower; The main pole of the lightning rod for high-voltage power lines should be perpendicular to the crossbar.

3) Install one set of iron towers in the middle of high-voltage transmission lines with a voltage level of 35kV or above.

Ⅱ. Standards for product production execution:

GB11032-2000（IEC60099-4:1991）《Communication seamless metal oxide lightning arrester》；

JB/T8952-2005《Composite jacket gapless metal oxide surge arrester for communication systems》；

JB/T10497-2005《Composite jackets for AC transmission lines and series gap metal oxide surge arresters》；

JB/T8459-2006《Method for Model Compilation of Lightning Arrester Products》。

《Design Specification for 110-750kV Overhead Transmission Lines》GB 50545

《Design Specification for Overvoltage Protection and Insulation Coordination of Communication Electrical Devices》GBT 50064

《General regulations and testing requirements for high voltage testing technology》 GB/T 16927.1

《Technical Regulations for Meteorological Survey of Electric Power Engineering》DL/T 5158

《Guidelines for lightning protection of overhead transmission lines》（Q/GDW 11452）

Ⅲ. Technical advantages

1.Effectively solving the occurrence of counterattacks and winding strikes caused by lightning strikes on high-voltage transmission lines, reducing the tripping rate of lightning strikes, improving the reliability of transmission, and truly achieving the processing of lightning wave waveforms. Technologically, it is targeted, practical, and innovative.

2.The product has a large lightning current capacity and strong resistance to lightning strikes.

3.Easy installation, no testing, no daily maintenance, and no increase in line inspection workload.

4. A dedicated lightning strike counting system (optional) that can collect lightning data for easy recording and analysis, solving the problems encountered in lightning protection work on power lines.

5.The installation method of lightning rods is flexible and variable, and the suspension and pile support methods can be independently considered according to the tower shape.

 

6.The equipment has reliable quality and a service life of over eight years