CN203085306U - Surge arrester for lightning protection of neutral line when neutral line and pole line of DC transmission are paralleled on the same pole - Google Patents

Abstract

The utility model relates to a lightning arrester of neutral conductor lightning protection when direct current transmission neutral conductor and polar line are put on hand with the pole belongs to electrician's lightning protection technical field. The lightning arrester comprises a lightning arrester body, an upper metal discharge ring, a lower metal discharge ring and an insulator, wherein the lightning arrester body, the upper metal discharge ring, the lower metal discharge ring and the insulator are coaxially installed from top to bottom; the upper end of the lightning arrester body is connected with a neutral line of a direct current transmission network through a connecting piece, and the lower end of the insulator is connected with an iron tower of the transmission network. The utility model provides a neutral conductor lightning arrester when direct current transmission neutral conductor and polar line are with pole and put up, its advantage is when the circuit normally operates, and the arrester does not influence the normal operating of circuit, and when taking place the thunderbolt, the arrester input work guarantees that the insulator of neutral conductor does not flashover, and the circuit normally operates with the voltage restriction on the neutral conductor.

Description

Surge arrester for lightning protection of neutral line when the neutral line and pole line of DC transmission are paralleled on the same pole

technical field

The utility model relates to a lightning arrester for lightning protection of the neutral line when the neutral line and the pole line of direct current transmission are mounted on the same pole, and belongs to the technical field of electrician lightning protection.

Background technique

Lightning is an atmospheric discharge phenomenon that often occurs in nature. It has a major impact on the operation of the power system. When strong lightning strikes the transmission line, the line will generally trip and cause a power outage. With the increase of the voltage level of the power system, the height of the transmission line is getting higher and higher, so the accident of lightning strikes on the conductors of the transmission line is more likely to occur, which is called lightning strike in the power system. With the implementation of my country's west-to-east power transmission strategy, many EHV and UHV DC transmission projects have been built and operated in my country. In some projects, due to the limitation of the line corridor, the neutral line and the line pole line are paralleled on the same pole. rack phenomenon. In terms of lightning protection, a new problem has emerged, that is, when the lightning strikes back or shields the pole line of the line, since the neutral line is closer to the pole line struck by lightning, the induced overvoltage on the neutral line is relatively large. It will cause multi-point flashover of the insulation along the line, and form a long-term arc, which will eventually lead to a major accident of bipolar blocking of the DC system.

Contents of the invention

The purpose of this utility model is to propose a lightning arrester for neutral line lightning protection when the neutral line and pole line of DC transmission are paralleled on the same pole, so as to solve the problem when the high voltage DC pole line and neutral line are paralleled on the same pole in the DC transmission network. The lightning protection problem of the neutral line can avoid the occurrence of bipolar blocking accidents.

The lightning arrester for neutral line lightning protection proposed by the utility model when the neutral line of DC transmission and the polar line are on the same pole includes the arrester body, the upper metal discharge ring, the lower metal discharge ring and the insulator. The arrester body, the upper metal The discharge ring, the lower metal discharge ring and the insulator are coaxially installed from top to bottom, and the upper metal discharge ring and the lower metal discharge ring are respectively set on the upper and lower parts of the insulator; the upper end of the arrester body is connected to the DC transmission through the connector The neutral line of the grid is connected, and the lower end of the insulator is connected with the iron tower of the transmission grid.

The utility model proposes a lightning arrester for neutral line lightning protection when the DC transmission neutral line and the polar line are on the same pole. , to limit the voltage on the neutral line to ensure that the insulator of the neutral line does not flash over and the line operates normally.

Description of drawings

Fig. 1 is a structural schematic diagram of a lightning arrester for neutral line lightning protection proposed by the utility model when the DC transmission neutral line and pole line are mounted on the same pole.

In Figure 1, 1 is the arrester body, 2 is the upper metal discharge ring, 3 is the lower metal discharge ring, and 4 is the insulator.

Detailed ways

The arrester for lightning protection of the neutral line when the neutral line and the polar line of the utility model are on the same pole for direct current transmission, its structure is shown in Figure 1, including the arrester body 1, the upper metal discharge ring 2, and the lower metal discharge ring 3 and insulator 4. The arrester body 1, the upper metal discharge ring 2, the lower metal discharge ring 3 and the insulator 4 are installed coaxially from top to bottom, and the upper metal discharge ring 2 and the lower metal discharge ring 3 are respectively set on the upper and lower parts of the insulator 4. The upper end of the arrester body 1 is connected with the neutral line of the direct current transmission network through a connecting piece, and the lower end of the insulator 4 is connected with the iron tower of the transmission network.

In the lightning arrester proposed by the utility model, the lightning arrester body 1 is composed of a plurality of ZnO valve plates, and the insulator 4 is made of silicon rubber and epoxy resin mandrel.

The working principle and working process of the lightning arrester proposed by the utility model are introduced in detail below in conjunction with the accompanying drawings:

In the arrester of the utility model, an air gap is formed between the two upper and lower metal rings. When the transmission line is working normally, the power frequency voltage or operating overvoltage all act on the air gap formed between the upper and lower metal rings, and the current flowing through the ZnO valve plate of the arrester body is zero. When the lightning overvoltage comes, the air gap formed between the upper and lower metal rings is broken down, and the ZnO valve plate constituting the arrester body is put into operation to limit the overvoltage caused by lightning and ensure that the neutral line insulator of the transmission network does not flash network, transmission lines are operating normally.

The lightning arrester of the present utility model has working parameters related to the direct current transmission line. When the polar line and the neutral line are mounted on the same pole, during normal operation, the neutral line will carry a certain voltage due to electrostatic induction, and the upper and lower metal wires will carry a certain voltage. The air gap formed between the rings is used to isolate the power frequency voltage, and the ZnO valve plate forming the main body of the arrester does not bear electrical stress. The size of the air gap should ensure that the power frequency voltage can be isolated during normal operation. In addition, due to the limited flow capacity of the ZnO valve plate, the air gap should ensure that it does not operate under the overvoltage of the system operation. The number of ZnO valve pieces should be able to ensure that the residual voltage after the arrester is operated is lower than the discharge voltage of the insulator used for the neutral line, so as to ensure that the insulator does not flashover.

Claims (1)

1. a lightning arrester for neutral line lightning protection when a direct current transmission neutral line and polar line are on the same pole, it is characterized in that the arrester comprises an arrester body, an upper metal discharge ring, a lower metal discharge ring and an insulator, and the arrester The body, the upper metal discharge ring, the lower metal discharge ring and the insulator are installed coaxially from top to bottom, and the upper metal discharge ring and the lower metal discharge ring are respectively set on the upper and lower parts of the insulator; the upper end of the arrester body is connected by The component is connected with the neutral line of the DC transmission network, and the lower end of the insulator is connected with the iron tower of the transmission network.

Images