JP2003051364A - Arrester device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that it is difficult to reduce an operation starting voltage and a discharge voltage of a voltage dependent nonlinear arrester element inserted between a power supply line and an earth, and it is necessary to arrange the arrester element also between power supply lines to protect between the power supply liens from a lightning surge. SOLUTION: This arrester device, which connects a series circuit of the voltage dependent nonlinear arrester element 21 and an open discharging gap 31 between the power supply line L1 and the earth E, sets the operation starting voltage of the arrester element 21 to be lower than a peak value of a voltage between the power supply line and the earth, and to be higher than an arc voltage in discharge of the discharging gap 31, and sets a discharge starting voltage of the discharging gap 31 to be higher than the peak value of the voltage between the power supply line and the earth. Thereby the discharge voltage of the arrester element 21 to the lightning surge is set to be low. The open discharging gap 31 self-restores by a leakage current even in a case of dew condensation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection device for protecting electric equipment connected to a power line from lightning damage, and more specifically, a single-phase two-wire system, a single-phase three-wire system, and a three-phase three-wire system. The present invention relates to a lightning protection device in which a voltage-dependent non-linear lightning protection element and a series circuit of a discharge gap are connected between each power supply line such as an AC circuit and ground.

[0002]

2. Description of the Related Art Voltage-dependent non-linear lightning protection devices (surge absorbers), which are individually arranged between a power supply line and a ground in an AC or DC power supply, or between power supply lines, usually have a voltage between the power supply line and the ground. A high operation start voltage is set so as not to operate with respect to the voltage between power supply lines. For example, in the single-phase two-wire type AC electric circuit shown in FIG. 9, in order to protect between the power supply lines (line phases) L1 and L2 and the ground E and between the power supply lines L1 and L2 from the lightning surge, the power supply lines L1 and L2 are connected to each other. The voltage-dependent non-linear lightning protection elements 1 and 2 are independently provided between the earth E, and the voltage-dependent non-linear lightning protection element 3 is independently provided between the power supply lines L1 and L2. The operation starting voltage of each of the lightning protection elements 1, 2 and 3 is set to be about 2 to 4 times higher than the peak value of the voltage between the power supply line and the ground so that each lightning protection element does not operate with respect to the voltage between the power supply line and the ground. ing.

In the single-phase three-wire type AC electric circuit shown in FIG. 10, a voltage is independently applied between the power source lines L1 and L2 and the earth E in order to protect between the power source line and the ground and between the power source lines from a lightning surge. Dependent non-linear lightning protection elements 4 and 6 are provided, and a voltage-dependent non-linear lightning protection element 5 is independently provided between the ground line (ground phase) N and the earth E, and each power supply line L1, L
2 and the ground line N between the voltage-dependent nonlinear lightning protection elements 7 and 8
Is provided. In this case, the operation starting voltage of the lightning protection elements 7 and 8 between the power supply line and the ground line is set higher than the peak value of the power supply voltage of the power supply line so as not to operate with respect to the voltage of each power supply line, The operation start voltage of the lightning protection elements 4, 5 and 6 between the ground and the ground is set to be higher than the maximum voltage increase value 600√2V on the low voltage side at the time of high voltage contact.

In the case of the three-phase three-wire type AC electric circuit shown in FIG. 11, voltage-dependent nonlinear lightning protection devices 9, 10, 11 are independently provided between the three-phase power supply lines U, V, W and the ground E. The voltage-dependent non-linear lightning protection devices 12, 13, 14 are independently provided between the power supply lines U, V, W. Then, the operation start voltage of the lightning protection devices 12, 13, 14 between the power supply lines is set higher than the peak value of the power supply voltage of each power supply line,
The operation start voltage of the lightning protection elements 9, 10, 11 between the power supply line and the ground is set to the maximum voltage rise value 60 on the low voltage side when the high and low voltages are touched.
It is set higher than 0√2V.

[0005]

As described above, the voltage-dependent non-linear lightning protection device arranged between the power supply line and the ground needs to set a high operation start voltage, and therefore, the limit voltage for the surge voltage is high. Then, in order to protect the power supply lines from the surge voltage, it is necessary to dispose the lightning protection element also between the power supply lines. In addition, it is difficult to improve the current withstand capability for lightning protection devices that require a high operation start voltage,
In addition, it is difficult to make the device thinner and smaller because it has a device thickness proportional to the operation start voltage.

For example, in the single-phase two-wire type AC electric circuit of FIG. 9, the operation starting voltage of the lightning protection element between the power supply line and the earth is about 2 to 4 times higher than the peak value of the voltage between the power supply line and the earth, and the limiting voltage. Cannot be lowered, and therefore
In order to protect the power supply lines from the surge voltage, it is necessary to install lightning protection devices having a high operation starting voltage between the power supply lines. In the case of the single-phase three-wire AC circuit of FIG. 10 and the three-phase three-wire AC circuit of FIG. 11, the operation starting voltage of the lightning protection element between the power supply line and the ground is higher than the maximum voltage rise value during high- and low-voltage contact. Because of the high voltage, the lightning protection device also has a high limit voltage, and it is necessary to install lightning protection devices between lines in order to protect each line from surge voltage.

As a result, it is difficult to reduce the number of lightning protection elements and miniaturize the lightning protection elements in a lightning protection device installed in a single-phase two-wire system, a single-phase three-wire system, a three-phase three-wire system AC circuit, etc. It was difficult to reduce the size and cost of the entire device.

The operation start voltage of the lightning protection element as described above can be lowered by connecting the discharge gap to the lightning protection element in series, but the discharge gap is originally connected to the lightning protection element having a high operation start voltage. However, the reduction range of the operation starting voltage of the lightning protection element becomes small, and it is difficult to reduce the limiting voltage, which is not a good solution to the above problems. Also,
For such a discharge gap, a discharge tube containing an inert gas is usually applied because stability and reliability of discharge characteristics are important, but the discharge gap of such a discharge tube containing an inert gas is In reality, it is expensive and it is difficult to connect it in series with a lightning protection device for economic reasons.

An object of the present invention is to provide a small-sized and low-cost lightning protection device capable of connecting a discharge gap to a lightning protection element in series in terms of performance and economy.

[0010]

In order to achieve the above object, the present invention provides a lightning protection device in which a series circuit of a voltage-dependent non-linear lightning protection device and a discharge gap is connected between a power line of a power line and a ground. The operating start voltage of is set lower than the peak value of the voltage between the power line and ground and higher than the arc voltage at the time of discharge of the discharge gap, and the discharge start voltage of the discharge gap is set below the peak value of the voltage between the power line and ground. It is characterized by being set high.

Here, the power supply circuit is preferably a single-phase two-wire AC circuit, a single-phase three-wire system, or a three-phase three-wire system AC circuit, but other AC circuits or DC circuits may be used. Good. The voltage-dependent non-linear lightning protection device has a structure in which electrodes such as aluminum are made to face each other on both sides of a plate-shaped voltage-dependent non-linear voltage device made of a material such as zinc oxide. It has a proportional relationship with the operation start voltage and the limit voltage of the element. Therefore, by setting the operation starting voltage of the lightning protection element lower than the peak value of the voltage between the power supply line and the ground, the lightning protection element becomes thin and small. Also, by setting the operation start voltage of the lightning protection element higher than the arc voltage during discharge of the discharge gap, the lightning protection element cuts off the arc of the discharge gap to cut off the follow current and lower the surge voltage limit voltage. You can By reducing the limiting voltage, it becomes possible to protect the surge voltage between the power supply lines without providing a lightning protection element between the power supply lines. By not providing the lightning protection device between the power supply lines, the number of lightning protection devices of the lightning protection device can be reduced, and it becomes easy to make the lightning protection device small in size and low in cost.

Further, in the present invention, the discharge gap connected in series to the lightning protection element is an open discharge gap formed by closing both ends of the discharge hole formed in the insulating sheet with a pair of metal parts. It is characterized in that a leak current is generated due to a potential difference between a voltage between a power supply line and a ground and an operation starting voltage of a lightning protection element when dew condensation occurs in a discharge hole of a gap.

The open discharge gap here has a discharge starting voltage proportional to the length of the discharge gap corresponding to the thickness of the insulating sheet sandwiched between the pair of metal parts. The metal component is a terminal plate or the like, and a discharge gap formed by closing the discharge hole of the insulating sheet with a pair of metal components may cause dew condensation in the discharge hole of the insulating sheet. When the inside of the discharge hole of the insulating sheet is condensed, a leakage current is generated by the potential difference between the voltage between the power supply line and the ground and the operation starting voltage of the lightning protection element set to be smaller than the peak value of this voltage. The leakage current is a current that causes the dew condensation portion of the discharge gap to be dried by heat generated by energization, and is a current that does not deteriorate the lightning protection element connected in series to the discharge gap. Since the dew condensation in the discharge gap is dried by the leakage current and self-recovered, there is no fear of deterioration of the discharge characteristics of the discharge gap, and it is not necessary to make the discharge gap structure a dew condensation prevention structure such as a waterproof structure or a sealed structure. Therefore, the discharge gap can be an open type with a simple structure such as simply sandwiching an insulating sheet between metal parts. Such an open type discharge gap is small and thin, and can be integrated into a lightning protection device. Becomes easier,
This makes it easier to reduce the size and cost of the lightning protection device.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
It will be described with reference to FIGS.

FIG. 1 shows a lightning protection device of the first embodiment applied to a single-phase two-wire type AC electric circuit, in which a voltage-dependent nonlinear lightning protection element 21 and a discharge gap 31 are connected in series between one power supply line L1 and an earth E. The circuit is connected, and a series circuit of the voltage-dependent nonlinear lightning protection device 22 and the discharge gap 32 is connected between the other power supply line L1 and the ground E. This lightning protection device is characterized in that the operation starting voltage of each of the lightning protection elements 21 and 22 is lower than the peak value of the voltage between the power supply lines L1 and L2 and the ground, and the arc voltage during discharge of the discharge gaps 31 and 32. This is because the discharge start voltage of the discharge gaps 31 and 32 was set higher than the peak value of the voltage between the power supply line and the ground.

For example, FIG. 1 shows a single-phase two-wire type AC electric circuit having a rated voltage of 100 V. In FIG.
The operation start voltage Va of each lightning protection element 21, 22 is smaller than the peak value of about 141 V, which is the peak value of the peak value of the AC 100 V electric circuit, and the discharge gap 31, 3 is smaller than the peak value of about 141 V.
2 is set to about 100 to 120 V, which is higher than the arc voltage Vd during discharge (about 40 to 50 V). Then, the discharge start voltage Vb of the discharge gaps 31 and 32 is set to a peak value of about 1
It is set to about 1000V to 1500V, which is sufficiently larger than 41V. The voltage Vc shown by the broken line in FIG. 2 is the operation start voltage of the conventional lightning protection device of FIG.

When a lightning surge current flows through one of the power supply lines L1, L2 and one of the discharge gaps 31, 32 starts to discharge, the lightning protection elements 21, 2 on the side of the discharge gap where the discharge has started.
2 starts operating, the surge current is suppressed, and the follow current is interrupted by the arc interruption in the discharge gap. The limiting voltage at this time is the limiting voltage V shown by the broken line in the voltage-current characteristic diagram of FIG.
It becomes -1. That is, the surge current i suddenly flows until the surge voltage v reaches the discharge start voltage Vb of the discharge gap, and then the surge voltage v drops sharply at the start of the operation of the lightning protection device and is limited to the limit voltage V-1. As a result, the electrical equipment of the AC circuit is protected from lightning surges, and the lightning protection element blocks the arc in the discharge gap due to the relationship of Va> Vd, thereby performing continuous current interruption. Limit voltage V shown by the solid line graph in FIG.
2 is the limiting voltage of the conventional lightning protection element of FIG. 9, and it can be seen from FIG. 3 that the limiting voltage V-1 of the lightning protection device according to the present invention can be made significantly smaller than the conventional limiting voltage V-2.
Since the limiting voltage V-1 between the power supply line and the ground is greatly reduced in this way, a lightning surge between the power supply lines can be achieved without disposing a voltage-dependent nonlinear lightning protection element independently between the power supply lines L1 and L2. Protection against. for that reason,
In FIG. 1, the lightning protection element between the power supply lines is omitted. Further, by reducing the limiting voltage between the power supply line and the ground, it becomes possible to improve the element current resistance of the lightning protection elements 21, 22 between the power supply line and the ground.

A lightning protection element 21 and a discharge gap 3 inserted between one power supply line L1 and the ground E of the AC electric circuit of FIG.
The series circuit of 1 or the series circuit of the lightning protection element 22 and the discharge gap 33 inserted between the other power supply line L2 and the ground E is assembled on a substrate (not shown) or in an insulating casing. It Also, the discharge gap 3
Although it is possible to apply a sealed structure or a waterproof structure that does not cause dew condensation as 1, 32, it is possible to make an open structure by combining with a lightning protection element 21, 22 whose operation start voltage is set low. It is desirable for the reason described below. For example, the lightning protection device 21 inserted between the power line L1 and the ground E
4 (A) and 4 (B) show a structural example of a lightning protection device in which a series circuit of a discharge gap 31 and a discharge gap 31 is incorporated in a housing and the discharge gap 31 has an open structure.

The lightning protection device 21 shown in FIG. 4 has a rectangular flat plate shape, and thin plate electrodes 41 are formed on both front and back surfaces thereof.
One end of a pair of terminal plates 42 is pressed against the outer surface of each electrode 41. The terminal plate 42 is a flat plate-shaped metal component having elasticity in the plate thickness direction. A lead-out terminal plate 45 is pressed against one surface of each of the other end portions of the terminal plate 42 via an insulating sheet 43. The lead-out terminal plate 45 is also a flat metal part. The insulating sheet 43 has a discharge hole 44 in a part thereof, and both ends of the discharge hole 44 are covered with a pair of terminal plates 42 and 45, so that the discharge hole 4
At 4, an open discharge gap 31 is formed. The discharge gap length of the discharge gap 31 is determined by the thickness of the insulating sheet 43.

The lightning protection element 21 and the discharge gap 31 described above are integrally housed in an insulative housing 46, and an elastic terminal plate 42 is pressed against the inner surface of the housing 46 so that the terminal plate 42 and the electrode 41 are connected.
The electrical and mechanical connection with the terminal board 42, the insulating sheet 43, and the lead-out terminal board 45 are well ensured. Since the terminal plates 42 and 45 and the insulating sheet 43 are simply in elastic contact with each other, that is, they have a non-sealed structure and a non-waterproof structure, the discharge gap 31 is thin and small, which is used as the lightning protection device 21. It becomes easy to connect in series and integrate, and it becomes easy to miniaturize and reduce the cost of the lightning protection device.

In the case of the open type discharge gap 31, dew condensation may occur in the discharge hole 44 of the insulating sheet 43. Therefore,
When the discharge gap 31 is condensed, a leakage current is generated due to the potential difference between the voltage between the power supply line and the ground and the operation starting voltage Va of the lightning protection device 21. This leakage current flows in the discharge hole 44 of the discharge gap 31 due to the discharge, and
The leakage current is a minute current that does not deteriorate the lightning protection element 21 connected in series to the discharge gap 31. Therefore, even if dew condensation occurs in the open discharge gap 31, the dew condensation is immediately eliminated by the leakage current and self-recovery is performed, and there is no fear of deterioration of the discharge characteristics of the open discharge gap 31.

The performance and structural characteristics of the first embodiment described above are as follows in the second embodiment of FIG. 5 and FIG.
Since the same applies to the third embodiment, the detailed description thereof will be omitted, and the second embodiment and the third embodiment will be sequentially described.

FIG. 5 shows a lightning protection device applied to a single-phase three-wire AC circuit, in which voltage-dependent non-linear lightning protection devices 23 and 24 and open-type discharge gaps 33 and 34 are provided between the power supply lines L1 and L2 and the ground E. A series circuit is connected, and an open-type discharge gap 35 is connected between the ground line N and the earth E to form a lightning protection device. In the case of a single-phase, three-wire type AC electric circuit having a rated voltage of 100V, an AC voltage of 10 V is used as in the first embodiment of FIG.
For the peak value of about 141V which is the peak value of the 0V electric path, the operation starting voltage of each lightning protection device 23, 24 is 100V which is smaller than the peak value and larger than the arc voltage at the time of discharge in the discharge gap
Set to about 120V, and the discharge start voltage of the discharge gaps 33 and 34 is set to 1000V to 15V, which is sufficiently larger than the peak value.
If set to about 00V, it becomes possible to interrupt the follow current and greatly reduce the limiting voltage as in the case of FIG. 3, and the same performance as that of the first embodiment of FIG. 1 is exhibited. Further, the series circuit of the lightning protection element 23 and the discharge gap 33, and the series circuit of the lightning protection element 24 and the discharge gap 34 can desirably have the same structure as in FIG.

The lightning protection device of the third embodiment shown in FIG. 6 is applied to a three-phase three-wire type AC electric circuit, and the voltage-dependent nonlinear lightning protection element 2 is provided between each power supply line U, V, W and ground E.
5, 26, 27 and open discharge gaps 36, 37, 38
Connected in series. In this case, for example, AC 200
Each lightning protection device 25,2 against the peak value of V line of about 283V
If the operation start voltage of Nos. 6, 27 is set to about 200V to 230V and the discharge start voltage of each of the discharge gaps 36, 37, 38 is set to about 1000V to 1500V, the limiting voltage becomes the limiting voltage V-1 in FIG. It will be similar. In addition, a series circuit of the lightning protection element 25 and the discharge gap 36, and the lightning protection element 2
6 and discharge gap 37 in series circuit, and lightning protection device 27
Each of the series circuits of the discharge gap 38 and the discharge gap 38 may have the same structure as that of FIG. 4, but the structure shown in FIG. 7 or 8 may be adopted to reduce the number of constituent parts of the lightning protection device including three series circuits. Is desirable. In the components shown in FIGS. 7 and 8, the same or corresponding parts as those of FIG. 4 are designated by the same reference numerals to avoid duplication of description.

FIG. 7 shows three of the series circuits (lightning protection device) of FIG. 4 having a common insulating sheet 43 'and a common lead-out terminal board 4.
It is integrated in 5 '. Common insulation sheet 43 '
Has discharge holes 44 at three locations and has a common lead-out terminal plate 45 '.
Simultaneously closes the three discharge holes 44 to form three open discharge gaps. The three lightning protection elements 25, 26 and 2 shown in FIG.
7 and the three open discharge gaps 36, 37, 38 are integrated and housed in a common housing 46 '. FIG. 8 is FIG.
3 of the above series circuit (lightning protection device) are integrated only by a common insulating sheet 43 ', and three independent lead terminal plates 45 are used.

[0026]

According to the present invention, by setting the operation starting voltage of the voltage-dependent non-linear lightning protection device lower than the peak value of the voltage between the power supply line and the ground and higher than the arc voltage during discharge of the discharge gap, The element is thin and small, and the limiting voltage when a lightning surge current flows can be lowered, and it is possible to protect between power supply lines from surge voltage even if there is no lightning protection element between power supply lines. There is an effect that it becomes easy to reduce the number of lightning protection devices of the lightning protection device and to make the lightning protection device small in size and low in cost. Further, there is also an effect that it is possible to easily improve the current resistance of the lightning protection element by reducing the limiting voltage.

Further, by making the discharge gap connected in series with the lightning protection element an open type which may cause condensation, the structure of the discharge gap can be simplified and inexpensive discharge gap parts can be used, and the structure is simple. Therefore, the lightning protection device can be easily integrated with the lightning protection device, and the lightning protection device can be further reduced in size and cost. Further, even if dew condensation occurs in the open-type discharge gap, the dew condensation is eliminated by the leakage current and self-recovery is performed, so there is no fear of deterioration of discharge characteristics, and a highly reliable lightning protection device can be provided.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a lightning protection device showing a first embodiment of the present invention.

FIG. 2 is a voltage waveform diagram in the power supply circuit of FIG.

FIG. 3 is a voltage-current characteristic diagram when a lightning surge occurs in the lightning protection device of FIG.

4 (A) is a front view of a main part showing a structural example of a lightning protection element and a discharge gap in the lightning protection device of FIG. 1, and FIG. 4 (B) is a side view.

FIG. 5 is a circuit diagram of a lightning protection device showing a second embodiment of the present invention.

FIG. 6 is a circuit diagram of a lightning protection device showing a third embodiment of the present invention.

7 is a front view of a main part showing a structural example of a lightning protection element and a discharge gap in the lightning protection device of FIG.

8 is a front view of a main part showing a structural example different from FIG. 7 of a lightning protection element and a discharge gap in the lightning protection device of FIG.

FIG. 9 is a circuit diagram of a conventional lightning protection device in a single-phase two-wire AC circuit.

FIG. 10 is a circuit diagram of a conventional lightning protection device for a single-phase three-wire AC circuit.

FIG. 11 is a circuit diagram of a conventional lightning protection device for a three-phase three-wire AC circuit.

[Explanation of symbols]

21-27 Voltage-dependent nonlinear lightning protection device 31-38 discharge gap, open discharge gap L1, L2 power line E earth Va Operation start voltage of lightning protection element Vb discharge start voltage Vd arc voltage V-1 limit voltage 41 electrodes 42 terminal board 43,43 'insulating sheet 44 discharge hole 45,45 'Lead-out terminal board 46,46 'housing

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Takayama             Otowa, 3-7-18 Meishin Town, Amagasaki City, Hyogo Prefecture             Denki Kogyo Co., Ltd. Head Office F-term (reference) 5E034 CA09 EA07 EA08                 5G013 AA01 AA04 BA02 CB16 DA03                       DA12

Claims (3)

[Claims] 1. A lightning protection device in which a series circuit of a voltage-dependent non-linear lightning protection device and a discharge gap is connected between a power supply line of a power supply line and a ground, and an operation starting voltage of the lightning protection device is set to a voltage between the power supply line and the ground. Lower than peak value, and
A lightning protection device, wherein the discharge gap is set to have a voltage higher than the arc voltage during discharge and the discharge gap has a discharge starting voltage set to be higher than the peak value of the voltage between the power supply line and the ground. 2. A single-phase two-wire system, a single-phase three-wire system, or a three-phase three-wire system, which is installed between each power supply line of the alternating current circuit and ground. Item 1
Lightning protection device described in. 3. The discharge gap is an open-type discharge gap formed by closing both ends of the discharge hole formed in the insulating sheet with a pair of metal parts, and a power source is provided when dew condensation occurs in the open-type discharge gap. The lightning protection device according to claim 1 or 2, wherein a leakage current is generated by a potential difference between a voltage between the line and the ground and an operation starting voltage of the lightning protection element.