JPH0140477B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protective gap device for series capacitors, and its object is to provide such a device which eliminates the need for an insulating support insulator for a pilot gap.

As is well known, a series capacitor protective gap device is connected across a series capacitor to protect the series capacitor from overvoltage.

Figure 1 is an electrical diagram showing a conventional device, with C ₁ ,
C ₂ is a series capacitor divided into two parts, whose midpoint is
_P1 is the connection point _P2 between the current suppression resistor _R2 and _the pilot gap PG via the bushing _B1 and the coupling resistor R1.
It is connected to the. S is a bypass switch, S ₁ ,
S ₂ is the switchgear.

Thus, the gap device G connected in parallel to the series capacitor _C1 has a first gap consisting of a first electrode.
a second gap Gb consisting of Ga and a second electrode supported by an arc runner;
comprising a main electrode disposed above the gap Gb and forming a main gap _G1 together with the second gap;
First cubicle with ionized gas exhaust hole
It is stored in CB ₁ . The one first electrode is insulated from the cubicle CB 1 via a bushing B ₂ , and the other first electrode is insulated from the cubicle CB ₁ via a bushing B 2 .
Cubicle with one electrode and main electrode of Gb
Installed on CB ₁ . This cubicle CB ₁
is insulated and supported by an insulating support insulator _I1 .

The gap device G′ on the series capacitor C ₂ side has almost the same structure, but the second cubicle CB ₂
The pilot gap PG, the coupling resistance R ₁ ,
The difference is that it houses a current suppression resistor _R2 . The pilot gap PG is insulated and supported from the cubicle CB ₂ by an insulating support insulator I ₂ . Note that the cubicles CB ₁ and CB ₂ have a two-tiered structure.

Therefore, an overvoltage is applied between the terminals of series capacitors C ₁ and C ₂ due to the short circuit current at the time of a transmission line fault, and when the voltage between the terminals of series capacitor C ₂ reaches the discharge starting voltage of pilot gap PG. , this discharges and the overvoltage is applied to the gap device G side. In this gap device, first the first gap Ga is discharged, and this arc reaches the main gap _G1 via the second gap Gb.

As the main gap G ₁ discharges, the full voltage is applied to the current suppression resistor R ₂ , so the other main gap G ₂ is also discharged, eventually bypassing the series capacitors C ₁ and C ₂ . . Subsequently, when the bypass switch S is closed and the electric arcs in both main gap G ₁ and G ₂ are extinguished, the ionized gas in the cubicles CB ₁ and CB ₂ is rapidly exhausted.

Therefore, when the above device is inactive, the upper terminal of the pilot gap PG, ie, the point _P2, is at the same potential as the second cubicle _CB2 , and a series capacitor is connected between the lower terminal and the second cubicle _CB2. A voltage of 1/2 of the total terminal voltage of C ₁ and C ₂ is applied. In the operation process of the above device, the operation of the pilot gap PG connects both terminals of the pilot gap and the second cubicle CB _{2 .}
During this period, a voltage of 1/2 of the total terminal voltage is applied, and the total terminal voltage is applied by the operation of the main gap _G1 in the first cubicle _CB1 .

Therefore, both terminals of the pilot gap PG must be insulated from the second cubicle CB ₂ using an insulator such as the insulating support insulator I ₂ as described above.

The present invention is a pilot gap PG, coupling resistance
The above drawbacks can be easily improved by simply changing the connection positions of R ₁ and current suppressing resistor R ₂ .

FIG. 2 shows one embodiment of the present invention, in which the short circuit current of the power transmission line during discharge of the _gap device is similar to that in _{FIG .} Lower terminal of → 2nd cubicle CB ₂ upper terminal → Main gap G ₂ → 2nd
Each part is connected so that it can flow through the path of the lower terminal of the cubicle.

The pilot gap PG is placed in the first cubicle _CB1 , that is, in the gap cubicle on the side where the upper electrode side terminal of the main gap _G1 is connected to one terminal of the series capacitor _C1 . is set up.

With this configuration, one terminal of the pilot gap PG and the first cubicle _CB1 housing it can be made to have the same potential. or,
When the main gap _G2 is discharged, the voltage applied between the other terminal of the pilot gap and the first cubicle is 1/2 of the total terminal voltage of the series capacitors _C1 and _C2 . It is half of that of .

FIG. 3 shows another embodiment of the present invention, in which the upper electrode side terminals of the main gaps G ₁ and G ₂ of the two cubicles CB ₁ and CB ₂ are connected to the terminals of the series capacitors C ₁ and C ₂ . The lower terminals (buttings B ₂ and B ₂ ) are connected to the main gear.
G ₁ and G ₂ are connected in series. A pilot gap PG, a coupling resistor R ₁ , and a current suppressing resistor R ₂ are housed in one of the cubicles (first cubicle CB ₁ in this embodiment).

As detailed above, according to the present invention, one terminal of the pilot gap can be installed with the same potential as the cubicle, and an insulator for insulating and supporting the pilot gap from the cubicle is unnecessary. Become. Moreover, only 1/2 of the total terminal voltage of the series capacitor is applied between the terminal of the pilot gap opposite to the cubicle potential and the cubicle. Therefore, the insulation dimension can be shortened and the cubicle can be designed to be compact, which is a remarkable effect.

[Brief explanation of drawings]

FIG. 1 is an electrical diagram showing a conventional device, and FIGS. 2 and 3 are electrical diagrams showing different embodiments of the present invention. C ₁ , C ₂ : Series capacitor, P ₁ : Midpoint, G ₁ ,
G ₂ : Main gap, CB ₁ , CB ₂ : Cubicle,
PG: Pilot gear.

Claims (1)

[Claims] 1. Main gaps arranged in parallel between the midpoint of a series capacitor divided into two and both terminals are each housed in a cubicle insulated from the ground, and the upper electrode of the main gap is set at the same potential as the cubicle, A pilot gap is housed in a cubicle on the side where a terminal connected to the upper electrode of the main gap is connected to one terminal of the series capacitor, one end of the pilot gap is connected to the cubicle, and the other end is connected to the midpoint. A protective gap device for series capacitors, characterized in that they are connected to each other.