The tower is 20-30 meters above the ground and exposed to open fields or high mountain areas, so there are many chances of being struck by lightning, and reliable lightning protection measures must be taken. Installing lightning rods on overhead power lines effectively shields the towers, ensuring the safe power supply of the lines. This new type of controllable discharge lightning rod is the latest research result obtained through long-term lightning protection research and extensive high-voltage testing. It has a large protection range, low flashover rate, low discharge current, and low induced overvoltage. The needle releases lightning cloud charges in the form of slowly changing small current upward lightning flash discharge, avoiding the harm of strong downward lightning flash discharge as the design basis. Through thousands of high-voltage discharge tests, it has been verified that the upward lightning caused by it has the characteristics of high protection reliability, wide range, and is not affected by the height of the protected object. Especially suitable for lightning protection of high-voltage transmission lines. Better ensure the safe and reliable operation of the power grid.

The controllable discharge lightning rod is designed based on the slow changing small current upward lightning flash discharge form to release lightning cloud charges and avoid strong downward lightning flash discharge hazards. Through thousands of high-voltage discharge tests, it has been verified that the upstream pilot triggered by it has the characteristics of high protection reliability, wide range, and is not affected by the height of the protective object.

1、 Functional features:

When the installation height of the controllable discharge lightning rod is ≤ 200M, its protection angle is 65 °, that is, when the protected object

Height Hx (M) protection radius Rx=2.14 (H-Hx) on the horizontal plane, where h is the controllable discharge lightning rod

The installation height (M).

The average amplitude of the main discharge current of the upstream lightning flash is 7kA.

When the steepness of the main discharge current of the upstream lightning flash is ≤ 5kA/μ S and the needle height H is ≤ 200M, the protection angle is 65 °.

The induced overvoltage generated during lightning flashes has been basically eliminated.

The protection angle is 55 ° when the probability of flanking is not greater than one in 100000.

Grounding resistance ≤ 10 Ω (in general areas); ≤ 30 Ω (in high resistance and unmanned areas).

Wind resistance capacity ≥ 50M/s.

Easy to install, maintenance free during use.

2、 Protection principle of controllable discharge lightning rod

Thunderclouds can discharge ground objects in two ways: upward lightning flashes and downward lightning flashes.

Generally speaking, during a downward lightning flash, the precursor develops from top to bottom, and the main discharge process occurs near the ground. Therefore, the charge supply is sufficient, and the discharge process comes rapidly, resulting in a large secondary value and high steepness of the lightning current; Upward lightning flash generally does not have a main discharge from the top to the bottom. Its discharge current is generated by a leading process that continues to develop upwards. Even if there is a main discharge, the secondary value of the discharge current is small and the steepness is low due to the difficulty of supplying charge from the thunderstorm cloud to the main discharge channel.

Based on the experience analysis that rockets with metal wires at the tail are more likely to trigger upward lightning than high-rise buildings, in order to successfully trigger upward lightning, the needle needs to meet the following requirements: before the upward lightning occurs, the space charge near the needle should be minimized as much as possible, so that the autonomous needle tip can develop discharge pulses upward. When it is necessary to trigger an upward lightning, the electric field strength at the needle tip should be high enough to quickly generate a discharge pulse.

3、 Performance indicators

a) The controllable discharge lightning rod installed on the top of buildings or line towers has sufficient mechanical strength and stability, and can withstand external forces such as 20mm thick ice cover and 50m/s wind speed.

b) The controllable discharge lightning rod is made of stainless steel material with good performance to ensure its service life of more than 20 years.

c) The structure of a controllable discharge lightning rod is shown in Figure 1, consisting of a main rod, a dynamic ring, an energy storage element, and a bracket.

圖 1 可控放電避雷針結(jié)構(gòu)示意圖

d) Before the controllable discharge lightning rod operates, the dynamic ring and main rod are insulated from the bracket, with a resistance greater than 106 Ω between them.

e) During the operation of the controllable discharge lightning rod, the energy storage element should be able to repeatedly store and release energy, and when the main rod discharges, there should be obvious corona generation at its front end.

f) The controllable discharge lightning rod has sufficient protection range, and its protection characteristics are shown in Figure 2:

Figure 2 Schematic diagram of the protection range of a single controllable discharge lightning rod

Ground protection radius r (m): r=2.14h

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

On the height hx (m) plane of the protected object, the protection radius rx (m): rx=2.14 (h-hx)

4、 Equipment delivery and acceptance

1. When delivering the equipment, check the following relevant equipment information and spare parts one by one according to the packing list

Are the spare parts complete

(1) Installation instructions or other relevant user manuals;

(2) Factory inspection report, product qualification certificate;

(4) 1 external hexagonal wrench (1 set of products comes with 1 wrench).

5、 Quality assurance and after-sales service

1. All processes, material tests, etc. (including purchased parts) during the product manufacturing process comply with the specifications

regulations.

2. The quality warranty period of the product is 1 year, with free maintenance within 1 year and lifetime warranty.

3. There are specialized technicians responsible for after-sales service and technical support of the product.