JPS6346932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compressed gas shield and disconnector suitable for use in systems of 1000 KV or higher, and in particular, an improved compressed gas switch having a parallel resistance with a large heat capacity in order to suppress overvoltage during switching. Regarding shiya disconnection.

In order to suppress overvoltage when switching on and off a system using a shield breaker, a parallel resistance is often provided in the shield breaker. The optimum resistance value in this case varies depending on the system conditions, but is approximately 300Ω to 1000Ω. If we take the conventional shiya disconnector in our country as an example,
For 500KV line breakers, a parallel resistance of about 1000Ω is installed only when the line is turned on. In this case, since the amount of heat generated by the resistor was not so large, there was no great difficulty in housing the resistor in the shield or disconnector.

On the other hand, it is being considered to be adopted in our country in the future.
For 1000KV to 1200KV system disconnectors, depending on the system conditions, it is necessary to use a parallel resistor not only when the system is turned on but also when there is a failure or disconnection, and in this case the resistance value may be as low as about 500Ω. There is. The thermal duty of the resistor is generally 2 times the high-speed reclosing duty (O-0.3S-CO-1m-CO) in a system under fault condition.
It is required to be able to perform the task several times in a row. By the way, the total amount of heat generated by the resistor is determined by W = 〓 ⁱ Vi ² /Rti (Vi: voltage, R: resistance, ti: energizing time), but since the cooling time of the resistor is long, the total amount of heat generated is generated at once. It is necessary to create a resistance that can be withstood.

Here, when calculating the calorific value for a 500KV system,
Maximum system voltage 550KV, resistance 1000Ω, energizing time
Assuming 0.01S, the above-mentioned input during duty is a total of 4 times, so from the above formula, W≒4×10 ⁶ Joul. The resistance of conventional 500KV shingle breakers only had to withstand this amount of heat. On the other hand, considering the amount of heat generated by the resistance when using a 500Ω resistor for both closing and disconnecting with a 1200KV disconnection switch, due to the above-mentioned duties, it will be applied 4 times and disconnected 6 times. The voltage between phase and 1/3 cycle (0.007S) is 1200KV/√3×1.3=900KV,
The voltage after the three-phase bridge is disconnected is 1200KV/√3=693KV. The total power-on time during power outage is 0.03S (including 0.007S).

Also, the voltage when turning on is 1200KV/√3=693KV,
The energization time is 0.01S. Operation responsibility 6
4 times, so W = 900 ² × 10 ⁶ / 500 × 6 × 0.007 + 693 ² × 10 ⁶ / 500 ×
6 x 0.023 + 693 ² x 10 ⁶ / 500 x 4 x 0.01 = 239 x ^{10 6} Joul, which is about 60 times the amount of heat generated for 500KV. Therefore, it is necessary to provide a resistance that can withstand this.

Therefore, the present invention has been made in view of the above points,
The purpose is to make it suitable for use in systems of 1000KV or more when a resistor that can withstand heat generation is incorporated through efficient spatial arrangement, and to reduce the tank diameter and axial length. It is an object of the present invention to provide a compressed gas insulator and disconnector whose overall outer diameter can be minimized.

As for the resistance arrangement of a grounded tank-type compressed gas shield disconnector with parallel resistance, it is reasonable to arrange the resistors evenly on both sides of the resistance contact at each shield disconnection point, as shown in Figure 1a. This is explained in detail in Japanese Patent Application No. 50-027972 (Japanese Unexamined Patent Publication No. 52-103268), which was previously developed by the present inventor. In Figure 1a, R ₁ and R ₂ are parallel resistances, S ₁ is a main contact, and S ₂ is a resistance contact. On the other hand, FIG.
1 shows the gas storage grounded tank, 2 shows the bushing, 3 shows the main circuit conductor, and 4 shows the 2 points. Further, 5 is an insulating support portion. In particular, the present invention
It is related to the structure of Fig. 2 shows the main parts of the present invention in detail, and Fig. 2 a shows a side view of one edge section, and Fig. 2 b shows a cross section taken along line A-A' in Fig. 2 a. . Also, Figure 2 c is B- in Figure 2 a.
A cross section of part B′ is shown. 11, 12, 1 in the figure
Reference numerals 3 and 14 are first, second, third, and fourth metal partition plates (hereinafter referred to as partition plates), and 15, 16, and 1 are provided on the outer peripheries of the partition plates 11 to 14, respectively.
Attach the electric field mitigation shields shown at 7 and 18. Hollow portions 12a and 13a are formed approximately at the center of the partition plates 12 and 13 located in between.
A plurality of resistors 20 constituting the parallel resistors R1 and R2, respectively, are arranged between the partition plates 11, 12 and 13, 14. Further, the partition plates 12 and 13 are connected by four insulating support members 21. 22 is the main contact point, and the hollow part 12 of the partition plates 12 and 13
a, 13a. 23 is a resistance contact, and this contact 23 is also located in the hollow portions 12a, 13a of the partition plates 12, 13, and
stored in between. The main contact 22 and the resistance contact 23 are each connected to a link mechanism 24.
As shown in the figure, resistors 20 are arranged separately on both sides of the resistive contact 23, and as shown in Figure 2b, a plurality of resistors 20 are arranged around the main contact 22 and the resistive contact 23, which are the cross sections. The entire structure has a nearly circular cross-sectional shape. Further, as shown in FIG. 2c, the central portion may be supported by an insulating support member 21, but it is also possible to attach parallel capacitors if necessary.

FIG. 3 shows the details of the installation of one of the plurality of resistors 20 shown in FIG.
1, 12 and 20 are the same partition plates and resistors as in FIG. 2, respectively. Reference numeral 31 denotes a spring element that provides contact pressure between the resistor 20 and the partition plate 11. In this embodiment, a resistor disc 30 having a plurality of holes in the center is used as the resistor. 32 is a resistance disk 30
The resistor 20 is fixed between the partition plates 11 and 12 by a tightening nut 33 using an insulating rod inserted through the resistor 20. By the way, as the resistance disk 30, it is common to use carbon that has the largest heat capacity and is practical, and is sintered into a disk shape with a diameter of 10 to 15 cm.

As explained earlier, compared to the 500KV system
For example, a 1200KV circuit breaker requires the use of a resistor that can withstand approximately 60 times the amount of heat generated, but the number of circuit breakers is planned to be 6, compared to 4 for 500KV.
If you increase the storage length of each resistor by 1.5 times and use 27 resistors in parallel for each 500KV resistor,
The heat generation per unit volume of the resistor is equal,
The same type of resistor as for 500KV can be used.
Moreover, it satisfies the conditions of the circuit principle shown in Fig. 1a, provides reliable contact pressure to each resistor disk as shown in Fig. 3, and furthermore, the entire structure is made small and efficient as shown in Fig. 2. becomes possible. Although FIG. 2 shows a case where 12 resistors 20 are connected in parallel, any number of resistors 20 can be installed in the same arrangement.

As explained above, according to the compressed gas switch and disconnector of the present invention, the compressed gas switch connects the series circuit in which the first and second parallel resistors are connected in series on both sides of the resistance contact in parallel to the main contact. In a metal disconnector, first and second metal partition plates each having a hollow portion formed approximately in the center are placed side by side with a space between them, and a space is provided between the two partition plates on both sides of the partition plates. The main contact and the resistance contact are arranged between the hollow portions formed in the first and second partition plates, and both ends thereof are arranged in parallel with each other. A plurality of resistors constituting the first and second parallel resistors are housed and arranged so as to protrude toward the third and fourth partition plates, and the plurality of resistors constituting the first and second parallel resistors are connected to the third and first partition plates and the second and second parallel resistors. Between the partition plates of No. 4, the main contacts and resistance contacts are arranged and fixed in a substantially circular shape around the main contacts and resistance contacts when viewed from the axial end side of the main contacts and resistance contacts. It can be used in systems of 1000KV or higher, as it has a built-in resistor that can handle the generated heat, and the tank diameter and longitudinal length (axial length) can be shortened, allowing the overall outer diameter to be minimized. The reason why this overall outer diameter can be minimized is as follows. In other words, a plurality of resistors constituting the parallel resistance are arranged and fixed in a substantially circular shape around the main contact and resistance contact when viewed from the axial end side of the main contact and resistance contact, so that there is no need to worry about the outside of the tank. This is because the diameter can be reduced, and since the main contact and the resistance contact overlap in the longitudinal direction with the plurality of resistors constituting the parallel resistance, the length in the longitudinal direction can be shortened.

[Brief explanation of the drawing]

Fig. 1 shows the entire compressed gas shield and disconnector according to the present invention, a is a circuit principle diagram, b is a schematic diagram of the entire configuration, and Fig. 2 is a detailed view of a cutaway section of the shroud in Fig. 1. A is a side view, b is an A-A' cross-sectional view of a, and c
3 is a sectional view taken along line BB' in a, and FIG. 3 is a sectional view showing the resistor in FIG. 2. R ₁ , R ₂ ... Parallel resistance, S ₁ ... Main contact, S ₂ ... Resistance contact, 1 ... Tank, 2 ... Bushing, 3 ... Main circuit conductor, 4 ... Shrink section, 5 ... Insulation support part, 11, 1
2, 13, 14... First, second, third, fourth metal partition plates, 15, 16, 17, 18... Electrostatic shield, 20... Resistor, 21... Insulating support member, 22...
Main contact, 23... Resistance contact, 24... Link mechanism, 3
0... Resistance disk, 31... Spring element, 32... Insulating rod.

Claims (1)

[Claims] 1. In a compressed gas shield and disconnector in which a series circuit in which first and second parallel resistors are connected in series on both sides of a resistance contact is connected in parallel to a main contact, a first , second metal partition plates are placed side by side with a space between them, and a third metal partition plate is placed on both sides of both partition plates with a space between them.
A fourth metal partition plate is arranged in parallel, and the first and second
The main contact and the resistance contact are placed between the hollow parts formed in the partition plate, and both ends thereof are connected to the third and fourth contacts.
A plurality of resistors constituting the first and second parallel resistors are arranged so as to protrude toward the partition plate side of the third and first partition plates and the second and fourth parallel resistance plates.
A compressed gas cylinder breaker is arranged and fixed in a substantially circular manner around the main contact and the resistance contact when viewed from the axial end side of the main contact and the resistance contact between the partition plates of the main contact and the resistance contact.