CN107834356A - A kind of insulator style voltage limiter of function with ground - Google Patents

Abstract

An insulator type voltage limiter with a grounding function belongs to the technical field of lightning protection for distribution lines. It is characterized in that: the discharge part includes an insulating mandrel (10), and an upper fitting (2) and a lower fitting (6) are respectively fixed on the upper and lower ends of the insulating mandrel (10), wherein the upper fitting ( 2) To support the overhead power distribution line (1), a ring electrode (5) is arranged between the insulating support section (3) and the discharge section (4), and between the ring electrode (5) and the lower fitting (6) A plurality of valve plates (11) are arranged close to each other; a grounding part (8) is also provided, the upper end of the grounding part (8) is connected to the lower fitting (6), and the lower end is connected to the earth (9). In this insulator-type pressure limiter with grounding function, the discharge section including the valve plate is placed at the lower fitting, so the valve plate is insulated from the overhead distribution line under normal conditions, so the valve plate is at a low potential , It will be turned on only when it is struck by lightning, which greatly prolongs the service life of the valve plate.

Description

An Insulator Type Voltage Limiter with Grounding Function

technical field

An insulator type voltage limiter with a grounding function belongs to the technical field of lightning protection for distribution lines.

Background technique

The overhead power distribution line is a first-class power supply network directly connected to the user, and its operation stability and safety are directly related to the user's power quality and safety. Because the insulation level of distribution lines is low, the operating environment of the lines is relatively complicated, and generally no special lightning protection measures are taken, so they are very vulnerable to lightning hazards. The overvoltage caused by direct lightning and the overvoltage caused by induced lightning can cause The flashover of the line insulation causes the line to trip and blackout. In areas with strong lightning activities, lightning strikes and power outages often occur on the distribution lines, and the reliability and stability of the system power supply are seriously affected. In order to improve the insulation level and lightning resistance level of lines, overhead insulated conductors are more and more widely used in power distribution. Although the overhead insulated wire can improve the lightning resistance level of the distribution line, once the insulated wire is struck by lightning and breaks down the insulation layer, it will hinder the movement of the arc along the wire, making the power frequency arc continue to burn at the fixed breakdown point, resulting in a disconnection accident. According to statistical data, there are a large number of lightning disconnection accidents in 10kV overhead insulated lines in my country, which seriously threaten the safe and stable operation of my country's power system.

At present, the lightning protection measures adopted by 10kV lines in my country mainly include the following types: 1) control tower grounding resistance, 2) lightning protection line protection for incoming lines, 3) install line arresters, 4) install line lightning rods, 5) improve line insulation level, 6) Coupled ground wires are erected on some lines, and voltage limiters are installed on some towers. At present, the line voltage limiters that have achieved better results are mainly used. Most of the 10kV distribution lines in our country are erected with cement poles and towers, and the cement poles and towers are naturally grounded. In some areas with high soil resistivity, the grounding resistance of the tower when it is naturally grounded is difficult to meet the actual engineering requirements. At this time, even if a voltage limiter is used along the distribution line, when the line is subjected to lightning overvoltage and the current discharge device operates, due to the large grounding resistance of the tower, the lightning overvoltage on the line may still exceed the insulation level of the line at this time, resulting in Counterattack, causing line insulation flashover.

In the patent No. 201320303847.8, a built-in column pressure limiter for overhead wires is disclosed, but there are still some shortcomings in this patent: (1) In this patent, through the common zinc oxide valve in this field However, in this patent, the zinc oxide valve plate is always in contact with the overhead power distribution line under normal conditions, so the zinc oxide valve plate is always at a high potential. The setting method of this valve plate and the gap must be To a certain extent, it affects the service life of the zinc oxide valve plate. (2) In this patent, the zinc oxide valve plate and the internal electrodes at both ends are set on the outside of a core tube, and then the core tube is set on the outside of the insulating mandrel, so its structure is more complicated, and at the same time it increases The difficulty of processing technology.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, to provide a method of placing the discharge section including the valve plate at the lower fitting, and the valve plate is insulated from the overhead power distribution line under normal conditions, so The valve plate is at low potential and will only conduct when it is struck by lightning, which greatly prolongs the service life of the valve plate. It is an insulator-type voltage limiter with a grounding function.

The technical solution adopted by the present invention to solve the technical problem is: the insulator type voltage limiter with grounding function includes a discharge part, and the upper end of the discharge part supports the overhead power distribution line, and the feature is that the discharge part includes The insulating mandrel runs through up and down, and the upper and lower ends of the insulating mandrel are respectively fixed with upper fittings and lower fittings, wherein the upper fittings support the above-mentioned overhead power distribution lines, and the discharge part is divided into insulating support sections from top to bottom and the discharge section, a ring electrode is set between the insulating support section and the discharge section, a discharge gap is formed between the ring electrode and the upper fitting, a number of valve plates are arranged between the ring electrode and the lower fitting, the ring electrode, the lower fitting and the valve The sheet is placed close to each other, and an insulating shed is set on the outside of the insulating support section and the discharge section; a grounding part is also provided, the upper end of the grounding part is connected to the lower fitting, and the lower end is connected to the ground.

Preferably, in the insulating support section, the insulating shed is directly sleeved on the outside of the insulating mandrel.

Preferably, the valve plate and the ring electrode are both sleeved on the outer ring of the insulating mandrel, the lower part of the ring electrode and the upper part of the lower fitting form a mounting ring respectively, and the insulating shed is sleeved between the ring electrode and the lower fitting. The mounting ring in the hardware and the outside of the disc.

Preferably, the ring electrode includes a power supply ring exposed between the insulating support section and the discharge section, the installation ring is located below the power supply ring, the installation ring is as thick as the valve plate, and the installation ring is as thick as the power supply ring. Grooves are formed between the rings.

Preferably, the lower fitting includes a lower fitting body, the mounting ring is located at the upper end of the lower fitting body, the mounting ring is as thick as the valve plate, and a groove is formed between the mounting ring and the lower fitting body.

Preferably, a groove is provided above the upper fitting, and the overhead power distribution line is placed in the groove.

Preferably, fastening bolts are provided at the bottom of the lower fittings, and the fastening bolts pass through the cross arm fixed to the concrete tower and the grounding part placed under the cross arm from top to bottom and are fixed by nuts.

Preferably, the grounding part includes a grounding wire and a grounding pin, the grounding wire and the grounding pin are fixed to the connecting plate at the same time, and a connecting ring is arranged on the upper end of the grounding wire, and the connecting ring is matched with the fastening bolt at the bottom of the lower fitting Install.

Compared with prior art, the beneficial effect that the present invention has is:

1. In this insulator-type voltage limiter with grounding function, the discharge section including the valve plate is placed at the lower fitting. The valve plate is insulated from the overhead distribution line under normal conditions, so the valve plate is in the Low potential, it will be turned on only when struck by lightning, which greatly prolongs the service life of the valve.

2. In this insulator-type voltage limiter with grounding function, by setting the grounding part, it overcomes the shortcomings of the large natural grounding resistance of the cement tower and cannot quickly evacuate the lightning energy. When there is a lightning overvoltage on the line, it can quickly discharge the lightning energy. , Enhance the lightning performance of the line. The grounding device is simple and portable, easy to implement, and convenient for on-site construction. The grounding wire is wrapped with an insulating sheath, which can effectively prevent personnel from getting an electric shock and ensure safe operation.

3. After the ring electrode, valve plate and lower fittings are placed, the insulating shed set outside the discharge section wraps the valve plate, the ring electrodes at both ends of the valve plate and the mounting ring of the lower fitting at the same time, ensuring Its insulating properties also ensure the reliable connection of the ring electrode, the valve plate and the lower fitting.

4. At the same time, by setting the installation ring on the ring electrode and the lower fitting, it plays a role of limiting the ring electrode, the valve plate and the lower fitting, and effectively avoids loosening between the ring electrode, the valve plate and the lower fitting. The valve plate and the ring electrode are directly sleeved on the outside of the insulating mandrel, so the structure is simpler.

Description of drawings

Figure 1 is a schematic diagram of the structure of an insulator-type voltage limiter with a grounding function.

Figure 2 is a cross-sectional view of the discharge section of the insulator-type voltage limiter with a grounding function.

Fig. 3 is a schematic diagram of the grounding part of the discharge section of the insulator type voltage limiter with a grounding function.

Among them: 1. Overhead power distribution line 2. Upper fittings 3. Insulation support section 4. Discharge section 5. Ring electrode 6. Lower fittings 7. Cross arm 8. Grounding part 9. Earth 10. Insulation mandrel 11. Valve plate 12. Insulating shed 13, connection ring 14, ground wire 15, connection plate 16, ground pin.

Detailed ways

Fig. 1～3 is preferred embodiment of the present invention, below in conjunction with accompanying drawing 1～3 the present invention is described further.

As shown in Figure 1, an insulator-type voltage limiter with a grounding function includes a discharge part and a grounding part 8. The upper end of the discharge part supports the overhead power distribution line 1 and is in an insulated state. The grounding part 8 is connected to the discharge part. The lower part is directly connected to the ground 9. When the overhead power distribution line 1 is struck by lightning, the leakage part is instantly turned on, and the large current generated by the lightning strike is discharged through the grounding part 8, and the large current is introduced into the ground 9.

Referring to Fig. 2, the leakage part includes an insulating support section 3 and a leakage section 4, and an insulating mandrel 10 penetrating up and down is arranged at the axial center of the insulating supporting section 3 and the draining section 4, and on the top of the insulating mandrel 10, The upper fittings 2 and the lower fittings 6 are respectively fixed to the lower two ends by means of conventional crimping, and a ring electrode 5 is also arranged between the insulating support section 3 and the discharge section 4 . A groove is opened on the upper surface of the upper fitting, and the overhead power distribution line 1 is placed in the groove, and the bottom of the lower fitting 6 is connected to the above-mentioned grounding part 8 . The insulating support section 3 includes an insulating shed 12 directly sleeved on the outer ring of the insulating mandrel 10 , and the outer ring of the discharge section 4 is also sleeved with an insulating shed 12 .

As shown in FIG. 2 , the inside of the discharge section 4 also includes a number of zinc oxide valve plates 11 sleeved on the outer ring of the insulating mandrel 10 , and the valve plates 11 are stacked on top of the lower fittings 6 from bottom to top in order. The ring electrode 5 is placed above the uppermost valve plate 11.

The ring electrode 5 includes a power feeding ring exposed outside the insulating shed 12 and a mounting ring concentrically arranged below the power feeding ring. The outer ring of the mounting ring is as thick as the valve plate 11, and a concave hole is formed between the mounting ring and the power feeding ring. groove. An inverted mounting ring having the same structure as that of the ring electrode 5 is provided above the lower fitting 6 , and a groove is formed between the mounting ring on the lower fitting 6 and the body of the lower fitting 6 .

After the ring electrode 5, the valve plate 11 and the lower fitting 6 are placed, the insulating shed 12 arranged outside the discharge section 4 connects the valve plate 11 and the ring electrode 5 at both ends of the valve plate 11 and the mounting ring of the lower fitting 6 at the same time. Wrapped inside it, it not only ensures its insulating properties, but also ensures the reliable connection of the ring electrode 5, the valve plate 11 and the lower fitting 6. At the same time, by setting the installation ring on the ring electrode 5 and the lower fitting 6, it can limit the position of the ring electrode 5, the valve plate 11 and the lower fitting 6, and effectively avoid the gap between the ring electrode 5, the valve plate 11 and the lower fitting 6. loose. The valve plate 11 and the ring electrode 5 are directly sleeved on the outside of the insulating mandrel 10, so the structure is simpler.

A fastening bolt is provided at the lower part of the lower fitting 6 body, and the fastening bolt passes through the cross arm 7 fixed to the concrete pole tower and the grounding part 8 placed under the cross arm 7 from top to bottom, and then is tightened by a nut to realize For the installation between the discharge part and the grounding part 8, the discharge part and the grounding part 8 are fixed to the concrete tower through the cross arm 7 at the same time.

As shown in Figure 3, the grounding part 8 includes a grounding wire 14 and a grounding pin 16. The lower end of the grounding wire 14 and the upper end of the grounding pin 16 are simultaneously fixed on the connecting plate 15 made of metal through the cooperation of bolts and nuts. The upper end of the upper end is provided with a connecting ring 13, and the grounding wire 14 is crimped inside the connecting ring 13, and the connecting ring 13 is fitted with the fastening bolt at the lower end of the above-mentioned lower fitting 6.

The specific working process and working principle are as follows:

Under normal circumstances, the insulator-type voltage limiter with grounding function uses its internal insulating mandrel 10 to support the overhead distribution line 1. Since the insulating mandrel 10 and its outer insulating shed 12 are all insulating materials, Therefore, no ground fault occurs at the overhead power distribution line 1 via the ground portion 8 .

When the overhead power distribution line 1 is struck by lightning, the large voltage is connected to the upper fitting 2 through the overhead power distribution line 1, and discharges through the upper fitting 2. When the upper fitting 2 discharges, the air gap between it and the ring electrode 5 is broken down. At this time, the large voltage is transmitted to the ring electrode 5 through the air gap. Since the valve plate 11 is arranged under the ring electrode 5, and the valve plate 11 is a non-linear resistor, the valve plate 11 is quickly turned on after receiving the large voltage. At this time, the large current generated by the large voltage passes through the valve plate 11, the lower fitting 6 and the grounding part 8 to realize the discharge of the large current. When the lightning energy discharge is completed, due to the nonlinear characteristics of the zinc oxide valve plate, the power frequency will be cut off quickly Continuous flow ensures that the system quickly returns to normal operation.

In this insulator-type voltage limiter with grounding function, the discharge section 4 including the valve plate 11 is placed at the lower fitting 6, so the valve plate 11 is insulated from the overhead power distribution line 1 under normal conditions, so The valve plate 11 is at a low potential and will only conduct when struck by lightning, which greatly prolongs the service life of the valve plate 11 .

In this insulator-type voltage limiter with grounding function, by setting the grounding part 8, it overcomes the shortcomings of the large natural grounding resistance of the cement tower and cannot quickly evacuate the lightning energy. When there is a lightning overvoltage on the line, the lightning energy can be quickly released. Enhance the lightning resistance performance of the line. The grounding device is simple and portable, easy to implement, and convenient for on-site construction. The grounding wire is wrapped with an insulating sheath, which can effectively prevent personnel from getting an electric shock and ensure safe operation.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or modify the equivalent of equivalent changes. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (8)

1. a kind of insulator style voltage limiter of function with ground, including discharge portion, discharge portion upper end support overhead distribution line （1）, it is characterised in that：Described discharge portion includes the insulation mandrel run through up and down（10）, in insulation mandrel（10）It is upper and lower Both ends are respectively fixed with gold utensil（2）With lower gold utensil（6）, wherein upper gold utensil（2）The described overhead distribution line of support（1）, aerial drainage Part is divided into insulating supporting section from top to bottom（3）With aerial drainage section（4）, insulating supporting section（3）With aerial drainage section（4）Between be provided with ring Shape electrode（5）, annular electrode（5）With upper gold utensil（2）Between form discharging gap, annular electrode（5）With lower gold utensil（6）Between set It is equipped with some valve blocks（11）, annular electrode（5）, lower gold utensil（6）And valve block（11）It is close to set, insulating supporting section（3）With let out Flow section（4）It is outside to be arranged with insulation full skirt simultaneously（12）；It is additionally provided with grounded part（8）, grounded part（8）The lower gold of upper end connection Tool（6）, lower end access the earth（9）.

2. the insulator style voltage limiter of function with ground according to claim 1, it is characterised in that：In described insulation branch Support section（3）In, described insulation full skirt（12）Directly it is set in insulation mandrel（10）Outside.

3. the insulator style voltage limiter of function with ground according to claim 1, it is characterised in that：Described valve block（11） And annular electrode（5）It is set in the insulation mandrel（10）Outer ring, annular electrode（5）Bottom and lower gold utensil（6）On Portion forms mounting ring, described insulation full skirt respectively（12）It is set in annular electrode（5）With lower gold utensil（6）In mounting ring and Valve block（11）Outside.

4. the insulator style voltage limiter of function with ground according to claim 3, it is characterised in that：Described annular electrode （5）Including exposed in insulating supporting section（3）With aerial drainage section（4）Between award electric ring, described mounting ring is positioned at awarding under electric ring Side, mounting ring and valve block（11）Deng thick and mounting ring and award and form groove between electric ring.

5. the insulator style voltage limiter of function with ground according to claim 3, it is characterised in that：Described lower gold utensil （6）Including lower gold utensil body, described mounting ring is located at the upper end of lower gold utensil body, mounting ring and valve block（11）Deng thick and installation Groove is formed between ring and lower gold utensil body.

6. the insulator style voltage limiter of function with ground according to claim 1, it is characterised in that：In described upper gold utensil （2）Top fluted, described overhead distribution line is set（1）It is placed in the groove.

7. the insulator style voltage limiter of function with ground according to claim 3, it is characterised in that：Described lower gold utensil （6）Bottom sets fastening bolt, and fastening bolt passes through the cross-arm fixed with cement shaft tower from up to down（7）And it is placed on cross-arm （7）The grounded part of lower section（8）Fixed afterwards by nut.

8. the insulator style voltage limiter of the function with ground according to claim 1 or 7, it is characterised in that：Described ground connection Part（8）Including earth lead（14）And grounding pin（16）, earth lead（14）And grounding pin（16）While and connecting plate （15）It is fixed, in earth lead（14）Upper end be provided with connection ring（13）, connection ring（13）With described lower gold utensil（6）Bottom Fastening bolt coordinate installation.