JP5007136B2 - Gas insulated switchgear - Google Patents

Description

The present invention relates to a gas insulated switchgear for electric power. More specifically, the present invention relates to improvement of the breaking performance of a gas circuit breaker using CO ₂ gas.

Conventionally, in a gas insulated switchgear, a switchgear utilizing the excellent shutoff performance and insulation performance of SF ₆ gas has been used for a backbone system. However, SF ₆ gas is extremely excellent in insulation performance and arc extinguishing performance, but is a warming gas having a global warming potential 23,900 times higher than that of CO ₂ gas. Since the time required to decrease to 1 / e times (about 37%) is as long as 3,200 years, once it is discharged into the atmosphere, its impact will accumulate cumulatively in the future. Is desired.

As one of alternative gas candidates, CO ₂ gas is currently considered as the most promising one. However, since CO ₂ gas is inferior in insulation performance and arc extinguishing performance compared with SF ₆ gas, it is not possible to simply replace the insulation gas while keeping the structure of the conventional gas insulated switchgear. For practical use of a gas circuit breaker using CO ₂ gas and hence a gas insulated switchgear, it is necessary to improve the shut-off performance and insulation performance by a structure or conductor surface treatment in accordance with the characteristics of the CO ₂ gas.

In view of this, there has been proposed one that employs an arc extinguishing system that actively uses arc energy to increase the puffer blowing pressure at the beginning of the breaking operation (Patent Document 1, Non-Patent Document 1). This CO ₂ gas circuit breaker has a structure in which an ablation element made of a polymer material is disposed in a space (puffer chamber) partitioned by a puffer cylinder and a puffer piston, and the thermal energy of the arc is taken into the puffer chamber from a hole in the inner wall. A part of the heat energy generated in the arc part at the time of current interruption is taken into the puffer cylinder to heat the stored CO ₂ gas and ablate the polymer material, and the puffer pressure is rapidly increased to blow the puffer The pressure is increased.

JP-A-9-63433 IEEE Trans.PE, Vol. 124, No. 3, 2004 (The Institute of Electrical Engineers of Japan B, Vol. 124, No. 3, 2004) P.476-483 “Development of an environmentally low load 72kV class CO2 gas circuit breaker model”

However, even if the puffer spray pressure is rapidly increased by actively using the arc energy at the beginning of the shutoff operation, the blower blows from the puffer cylinder at the beginning of the shutoff, especially immediately after the start of the shutoff (particularly up to about 1/3 of the shutoff stroke). It is difficult to cool until the arc can be extinguished with CO ₂ gas, which has a low specific heat compared to SF ₆ gas and is inferior in cooling capacity, and has a problem that it is difficult to reliably shut off. Even if the cooling can be achieved, the separation distance between the electrodes is small, and it is difficult to withstand a transient overvoltage applied between the electrodes with CO ₂ gas having a lower withstand voltage than SF ₆ gas. Although it is conceivable to strengthen the blowing from the puffer cylinder and to secure the separation distance, it is necessary to greatly increase the operating force and the high-speed operation of the moving parts, so the circuit breaker is increased in size and cost. Leads to. In addition, since arc extinguishing is not performed by pressure but is performed by cooling, even if a large amount of CO ₂ is flowed at a time, it is only wasted, so that the interruption can be effectively performed. Needs to keep blowing CO ₂ for a certain time. In particular, it is preferable to flow a large amount in the latter half of the stroke that is easy to extinguish, but not flowing CO ₂ gas at the beginning of the shut-off operation also causes a problem of burning and damaging the insulator around the electrode.

In addition, CO ₂ having a small specific heat is easily warmed and expanded. For this reason, the hot gas generated by the arc discharge at the time of interruption becomes large at high temperature, so if it is filled with the surroundings of the electrode and the shield of the same potential as the electrode without being cooled, There is a problem that the insulation between the case and the barrier performance is deteriorated.

Furthermore, since CO ₂ gas has inferior insulation performance compared to SF ₆ , insulation breakdown due to the structure of the switchgear that was not a problem with conventional gas switches, concentration of electric field due to minute protrusions, partial discharge, etc. Have problems that occur. In the switchgear using CO ₂ gas that has been proposed so far, the improvement of the insulation characteristics due to the treatment of the conductor surface is not taken into consideration as a measure against the deterioration of the insulation performance of the insulation gas itself, and the heat dissipation characteristics are good and the current-carrying performance From the aspect, the development of good surface treatment technology is required.

An object of the present invention is to provide a gas-insulated switchgear that can ensure insulation performance even when the insulating gas is changed from SF ₆ to CO ₂ .

In order to achieve this object, the invention according to claim 1 is linked to a fixed side electrode, a movable side electrode that can be contacted and separated from the grounded tank filled with CO ₂ gas, and the movable side electrode. A puffer cylinder, a fixed piston that forms a puffer chamber between the puffer cylinder, and a fixed side electrode that surrounds the movable side electrode and discharges CO ₂ gas blown from a blow-off port provided on the anti-fixed piston side of the puffer cylinder. In a gas insulated switchgear including a puffer-type gas circuit breaker provided with an insulating nozzle that leads to an opening gap between the movable electrode and the movable side electrode, the puffer chamber has at least two chambers, a first puffer chamber and a second puffer chamber. The first communication port that is always open in the partition wall between the first puffer chamber and the second puffer chamber, and the separation between the fixed side electrode and the movable side electrode proceeds. Open when A second communication port is provided for, it is the CO ₂ gas ejected from the second puffer chamber in the first puffer chamber that is ejected from the inner to the outlet of the insulating nozzle.

Therefore, in the puffer-type gas circuit breaker, the fixed side electrode and the movable side electrode are in contact with each other at normal times, and these electrodes and conductors are insulated from the ground tank by CO ₂ gas. When the movable side electrode moves and leaves the fixed side electrode due to the cutoff command, an arc is generated between the two electrodes. This arc grows longer as the movable side electrode moves away from the fixed side electrode. The puffer cylinder also moves in conjunction with the movement of the movable electrode, and the CO ₂ gas in the second puffer chamber is compressed by the fixed piston.

Two communication ports are provided in the partition wall between the first puffer chamber and the second puffer chamber, but immediately after the opening of the fixed side electrode and the movable side electrode is started (immediately after the start of blocking). ), The second communication port is closed, and the compressed CO ₂ gas in the _second puffer chamber flows from the first communication port to the first puffer chamber and is blown from the blowout port to surround the electrode periphery. Cool the insulation.

When the movable side electrode and the puffer cylinder further move and the separation between the fixed side electrode and the movable side electrode proceeds, the second communication port opens, and from the second communication port in addition to the first communication port CO ₂ gas flows into the first puffer chamber. For this reason, the amount of CO ₂ gas flowing from the second puffer chamber into the first puffer chamber increases, and a large amount of CO ₂ gas is blown from the outlet. A large amount of the blown CO ₂ gas is guided to the insulating nozzle and flows into the separation gap between the fixed side electrode and the movable side electrode, and the long-grown arc is cooled and extinguished.

Furthermore, the gas insulated switchgear according to claim 2 is obtained by subjecting the surface of an aluminum member having a higher potential than the grounding member to a turfrum treatment.

  Therefore, the surface of the aluminum member becomes a smooth surface without unevenness. Here, the aluminum member having a higher potential than the grounding member, for example, a grounding tank or a grounding sheath, is, for example, a gas-insulated bus conductor or shield, a gas circuit breaker conductor or shield, or the like.

The gas insulated switchgear according to claim 1, wherein the puffer chamber is partitioned in series into at least two chambers, a first puffer chamber and a second puffer chamber, and between the first puffer chamber and the second puffer chamber. A first communication port that is always open and a second communication port that opens when the separation of the fixed electrode and the movable electrode proceeds, and the second puffer chamber Since the CO ₂ gas blown into the first puffer chamber is blown out from the blowout port to the inside of the insulating nozzle, the amount of CO ₂ gas blown from the blowout port is small at the initial stage of shut-off, which is difficult to extinguish. After a certain amount of time elapses, the arc can be easily extinguished. That is, CO ₂ gas can be blown in two stages from the outlet. Therefore, the puffer CO ₂ gas in the cylinder can be efficiently can be used to extinguish arc generated between the electrodes more reliably. As a result, it is possible to improve the shutoff reliability even if CO ₂ gas having a specific heat smaller than that of SF ₆ gas and inferior in cooling capacity is used as the insulating gas. In addition, since the CO ₂ gas is blown in an amount necessary to stably maintain the arc on the electrode axis even in the early stage of interruption, and the insulator around the electrode can be cooled, In addition, it is possible to prevent the burnout / damage of the insulator around the electrode. At the same time, since the amount of CO ₂ gas blown to the minimum necessary at the beginning of shut-off, the generation of hot gas at the start of shut-off is suppressed to prevent the surroundings of the conductor from becoming hot at an early stage after the start of shut-off. Thus, it is possible to ensure the insulation against the ground transient recovery voltage more reliably.

Furthermore, in the gas insulated switchgear according to claim 2, since the surface of the aluminum member having a higher potential than that of the grounding member is subjected to the tuffram treatment, the surface of the aluminum member can be made smooth without any unevenness. it can. If the surface has irregularities, electrons are likely to be emitted from the convex portions and the insulation resistance performance deteriorates. In the present invention, since the surface of the aluminum member can be a smooth surface without unevenness, the insulation resistance can be improved. Moreover, since the taffram treatment does not cover the surface of the aluminum member with a thick film, the heat dissipation performance is not deteriorated.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 and 2 show a first embodiment of a gas insulated switchgear according to the present invention. The gas insulated switchgear includes, for example, a gas circuit breaker 1, a bus disconnector 36, a line side circuit breaker 37, a line side grounding device 38, a grounding device 39, an instrument transformer 40, a cable connector 41, a current transformer 42, a busbar. 43 is included. In FIG. 1, the gas circuit breaker 1 of FIG. 2 is shown sideways. Moreover, the upper half part of FIG. 1 shows a state before shutting down, and the lower half part shows a state immediately after the start of shutting down.

The gas-insulated switchgear includes a fixed side electrode 4, a movable side electrode 5 that can be contacted and separated from the ground tank 3 filled with CO ₂ gas 2, a puffer cylinder 6 that is linked to the movable side electrode 5, A fixed piston 8 that forms a puffer chamber 7 between the puffer cylinder 6 and a CO ₂ gas 2 that surrounds the movable electrode 5 and is blown out from a blow-out port 9 provided on the side of the puffer cylinder 6 opposite to the fixed piston 8. The puffer chamber 7 includes a puffer-type gas circuit breaker 1 that includes an insulating nozzle 11 that leads to an opening gap 10 between the fixed side electrode 4 and the movable side electrode 5, and the puffer chamber 7 includes a first puffer chamber 7 a A first communication port 13 that is partitioned in series into at least two chambers with the second puffer chamber 7b and is always open to the partition wall 12 between the first puffer chamber 7a and the second puffer chamber 7b. And fixed side electrode 4 and movable side A second communication port 14 is provided which opens when the progress in opening of the pole 5, the second puffer chamber 7b of the first CO was injected into the puffer chamber 7a ₂ gas 2 an insulating nozzle 11 It is ejected inward from the outlet 9.

The first puffer chamber 7a guides the CO ₂ gas 2 flowing from the first communication port 13 and the second communication port 14 to the air outlet 9, and is not so wide. On the other hand, the second puffer chamber 7b is somewhat wide and can store a sufficient amount of CO ₂ gas 2 for arc extinguishing. The first communication port 13 is formed with a small diameter, and the second communication port 14 is formed with a large diameter. For example, the diameter of the first communication port 13 is such that the opening area of the second communication port 14 is 1/5 or less.

  An opening mechanism 15 is provided at the second communication port 14. The opening mechanism 15 includes, for example, a valve body 16 that closes the second communication port 14 from the first puffer chamber 7a side, a shaft 17 that is connected to the valve body 16 from the second puffer chamber 7b side, and a rear shaft 17 A spring seat 18 provided at the end and a spring 19 provided in a contracted state between the spring seat 18 and the partition wall 12 are configured. When the partition wall 12 approaches the fixed piston 8 by the movement of the puffer cylinder 6, the shaft 17 is pushed toward the first puffer chamber 7a by the fixed piston 8. Thereby, since the valve body 16 which has blocked the 2nd communication port 14 leaves | separates from the partition wall 12, the 2nd communication port 14 opens. For example, the second communication port 14 is opened by a movement of about 1/3 of the entire stroke in which the puffer cylinder 6 moves when shut off.

During normal operation, as shown in the upper half of FIG. 1, the fixed electrode 4 and the movable electrode 5 are in contact with each other, and, for example, a high-voltage current flows through these electrodes 4 and 5 and the puffer cylinder 6. The ground tank 3 is filled with CO ₂ gas 2 so that the electrodes 4 and 5 and the puffer cylinder 6 and the ground tank 3 are insulated.

When the movable side electrode 5 moves and moves away from the fixed side electrode 4 by the cutoff command, an arc 20 is generated between the electrodes 4 and 5 as shown in the lower half of FIG. The arc 20 grows longer as the movable side electrode 5 moves away from the fixed side electrode 4. The puffer cylinder 6 is also moved in conjunction with the movement of the movable electrode 5, and the CO ₂ gas 2 in the second puffer chamber 7 b is compressed by the fixed piston 8. In this state, since the second communication port 14 is blocked by the opening mechanism 15, the compressed CO ₂ gas 2 in the _second puffer chamber 7 b passes from the first communication port 13 to the first puffer chamber. It flows into 7a, and is further blown from the blowout port 9, and the electrodes 4, 5 and the like are cooled. The first communication port 13 has a relatively small diameter, and the flow rate of the CO ₂ gas 2 that flows from the second puffer chamber 7 b into the first puffer chamber 7 a and is blown from the blowout port 9 is relatively small.

When the movable side electrode 5 and the puffer cylinder 6 further move and the separation between the fixed side electrode 4 and the movable side electrode 5 proceeds, the rear end of the shaft 17 of the opening mechanism 15 hits against the fixed piston 8 and is pushed into the second communication. The mouth 14 opens. For this reason, the amount of the CO ₂ gas 2 flowing from the second puffer chamber 7b into the first puffer chamber 7a is increased, and a large amount of CO ₂ gas 2 is blown from the outlet 9. A large amount of the blown CO ₂ gas 2 is guided to the insulating nozzle 11 and flows to the separation gap 10 between the fixed side electrode 4 and the movable side electrode 5 to cool and extinguish the arc 20 that has grown long. Arc.

FIG. 3 shows an example of a temporal change in the flow rate of the CO ₂ gas 2 blown from the blowing port 9. When the movable electrode 5 and the puffer cylinder 6 are moved by the start of shutoff, the CO ₂ gas 2 in the second puffer chamber 7 b is compressed and flows into the first puffer chamber 7 a from the first communication port 13 and from the blowout port 9. Although it is sprayed, the amount of spraying is small at this stage (first stage). The first stage spraying is continued for 10 to 15 ms, for example.

When the second communication port 14 opens, the CO ₂ gas 2 in the second puffer chamber 7b flows from the two communication ports 13 and 14 into the first puffer chamber 7a, so that the amount of blowing increases. Since the second communication port 14 has a larger flow path area than the first communication port 13, the amount of spraying at this stage (second stage) is greatly increased. The amount of spraying in the second stage is, for example, 5 times or more compared to the amount of spraying in the first stage.

The arc 20 generated at the time of shut-off is not easily extinguished even if a large amount of CO ₂ gas 2 is blown because the puffer blowing pressure and the separation distance are insufficient at the beginning of the shut-off. On the other hand, when a certain amount of time elapses from the generation, for example, when 10 to 15 ms elapses, the arc 20 is easily extinguished. As shown in FIG. 3, arc extinguishing is difficult even when a large amount of CO ₂ gas 2 is blown, and at the initial stage of shut-off, the first stage blowing is performed to save CO ₂ gas 2 and arc extinction becomes possible. By performing the second stage spraying in which the amount of CO ₂ gas 2 sprayed is increased, the CO ₂ gas 2 spraying time can be extended. For example, high pressure spraying can be maintained for a time of 40 ms or longer. For this reason, the arc 20 can be extinguished more reliably and the reliability can be improved. In addition, since the CO ₂ gas 2 is ejected even in the early interruption period when it is difficult to extinguish the arc 20, the electrodes 4, 5 and the like can be cooled, and the arc 20 can be prevented from being burned and damaged. it can. That is, the CO ₂ gas 2 in the puffer chamber 7 can be used efficiently by performing the two-stage spraying.

In addition, since the amount of blowing of the CO ₂ gas 2 is reduced at the initial stage of interruption when it is difficult to extinguish the arc 20, the generation of hot gas can be suppressed by that amount. For example, it is possible to reduce nearly 1/3 of the amount of hot gas generated before arc extinction. In addition, since the generation of hot gas at the initial stage of shut-off is suppressed, it is possible to prevent the surroundings of the conductor from becoming hot at an early stage after the start of shut-off, and shut-off that is more likely to cause dielectric breakdown in relation to the ground transient recovery voltage. It is very effective in preventing a decrease in dielectric strength immediately after.

In the above description, the puffer chamber 7 has two puffer chambers 7 a and 7 b, the first communication port 13 that is always open to these partition walls 12, the fixed side electrode 4, and the movable side electrode 5. The second communication port 14 that is opened when the separation from the _second gas is opened, so that the CO ₂ gas 2 is blown in two stages. For example, the structure is not limited to the above-described structure. For example, the puffer chamber 7 is a single chamber and two types of blowout ports 9 for blowing the CO ₂ gas 2 in the puffer chamber 7 are provided. Two-stage spraying may be performed by time control, or other structures may be used.

  In the above description, the opening mechanism 15 is constituted by the valve body 16, the shaft 17, the spring seat 18, and the spring 19, but when the separation between the fixed side electrode 4 and the movable side electrode 5 proceeds, The configuration is not limited to this as long as the two communication ports 14 can be opened.

  Next, a second embodiment of the gas insulated switchgear according to the present invention will be described. The gas insulated switchgear of the present embodiment is different from the gas insulated switchgear of the first embodiment in the puffer type gas circuit breaker. A gas insulated switchgear according to this embodiment is shown in FIGS. In FIG. 4, the gas circuit breaker 1 of FIG. 2 is shown sideways. Moreover, the upper half part of FIG. 4 shows a state before blocking, and the lower half part shows a state after blocking.

The gas-insulated switchgear includes a fixed side electrode 4, a movable side electrode 5 that can be contacted and separated from the ground tank 3 filled with CO ₂ gas 2, a puffer cylinder 6 that is linked to the movable side electrode 5, A fixed piston 8 that forms a puffer chamber 7 between the puffer cylinder 6 and a CO ₂ gas 2 that surrounds the movable electrode 5 and is blown out from a blow-out port 9 provided on the side of the puffer cylinder 6 opposite to the fixed piston 8. It includes a puffer-type gas circuit breaker 1 having an insulating nozzle 11 that leads to an opening gap 10 between the fixed side electrode 4 and the movable side electrode 5, and shields the periphery of the conductor 21 in the ground tank 3. 22, a space 23 for temporarily retaining hot gas generated at the time of shut-off is secured inside the shield 22.

In the normal state, as shown in the upper half of FIG. 4, the fixed side electrode 4 and the movable side electrode 5 are in contact with each other, and, for example, high voltage current flows through these electrodes 4 and 5 and the puffer cylinder 6. The ground tank 3 is filled with CO ₂ gas 2 so that the electrodes 4 and 5 and the puffer cylinder 6 and the ground tank 3 are insulated.

When the movable side electrode 5 moves and leaves the fixed side electrode 4 due to the cutoff command, an arc 20 is generated between the arc contacts 4a and 5a of the electrodes 4 and 5 as shown in the lower half of FIG. To do. This arc 20 grows longer as the movable electrode 5 moves away from the fixed electrode 4. Also, the puffer cylinder 6 moves in conjunction with the movement of the movable electrode 5, and the CO ₂ gas 2 in the puffer chamber 7 is compressed by the fixed piston 8. The compressed CO ₂ gas 2 is blown from the blowing port 9 toward the separation gap 10 between the electrodes 4 and 5. The blown CO ₂ gas 2 is guided to the insulating nozzle 11 and flows to the separation gap 10 between the electrodes 4 and 5 to cool the arc 20 and extinguish it.

  Hot gas generated by cooling the arc 20 temporarily remains in the space (temporary storage space) 23 inside the shield 22 and does not diffuse immediately. For this reason, it is possible to prevent the hot hot gas from immediately reaching the periphery of the conductor 21, and to prevent the periphery of the conductor 21 from becoming a high temperature at an early stage after the start of interruption.

  The shield 22 is a portion where the potential difference with the ground tank 3 is the largest and dielectric breakdown is likely to occur. Since the insulation deteriorates due to the temperature rise, the deterioration of the insulation can be prevented by preventing the surroundings of the shield 22 from becoming high temperature. In particular, since the voltage applied to the shield 22 rises transiently immediately after the start of the interruption (ground transient recovery voltage), dielectric breakdown is more likely to occur, but hot gas is temporarily supplied to the temporary storage space 23 inside the shield 22. By keeping it in place, it is possible to prevent the hot gas from immediately reaching the periphery of the shield 22 and to prevent the surroundings of the shield 22 from becoming a high temperature at an early stage after the start of the interruption. Insulation resistance against the recovery voltage can be improved. Further, since the path until the hot gas reaches the periphery of the shield 22 is increased by the amount that the diffusion of the hot gas is obstructed by the shield 22, the temperature of the hot gas when reaching the periphery of the shield 22 is increased accordingly. Can be lowered. For this reason, the temperature rise around the shield 22 can be suppressed, and the deterioration of the insulating property can also be suppressed from this.

  The volume of the empty space 23 in the shield 22 is determined, for example, in relation to the amount of hot gas generated at the time of blocking. That is, at least a volume that can hold the hot gas in the shield 22 is ensured in the shield 22 until the transient recovery voltage of the conductor 21 immediately after the start of interruption sufficiently attenuates.

Further, the gas insulated switchgear according to the present embodiment is provided with a flow path 25 through which the CO ₂ gas 2 after cooling the arc 20 passes inside a hollow insulated support cylinder 24 fixed to the ground tank 3 and supporting the conductor 21. . The hollow insulating support cylinder 24 has a cylindrical shape, and is disposed in the forward direction of the CO ₂ gas 2 flowing around the arc 20. One end of the hollow insulating support cylinder 24 is fixed to the side plate 3 a of the ground tank 3 by a mounting bracket 26. A conductor 21 is attached to the other end of the hollow insulating support cylinder 24. The mounting bracket 26 is provided with a slit 27 that allows the internal space of the hollow insulating support cylinder 24 to communicate with the external space. For this reason, gas can pass through the internal space of the hollow insulating support cylinder 24, and the flow path 25 is formed.

  In the present embodiment, a flow rate control unit 29 that also serves as a heat exchanger is provided in the gas blowing port 24 a of the hollow insulating support cylinder 24. The flow rate of the hot gas mainly flows through the central portion of the hollow insulating support cylinder 24 by the flow rate control unit 29. The flow rate control unit 29 is, for example, a swirler, and makes the hot gas flow swirl so as to mainly flow through the center of the hollow insulating support cylinder 24. In addition, a plurality of pleats 30 are provided on the inner wall surface of the hollow insulating support cylinder 24, and the creeping distance is increased.

  Conventionally, the inner space of the hollow insulating support cylinder 24 is closed and the gas cannot pass therethrough, so that the hot gas generated by the blocking enters the hollow insulating support cylinder 24. There was no. That is, the hollow insulating support cylinder 24 is an unused space.

  In the present invention, by providing the slit 27, the flow path 25 that can pass through the hollow insulating support cylinder 24 is provided, and hot gas can enter. The hot gas that has entered the flow path 25 flows through the slit 27 and out of the hollow insulating support cylinder 24. The outflow position of the hot gas is a position sufficiently away from the conductor 21. For this reason, it is possible to prevent the hot hot gas from immediately reaching the periphery of the conductor 21, and to prevent the periphery of the conductor 21 from becoming a high temperature at an early stage after the start of interruption. For this reason, the point which can improve the insulation-proof performance with respect to the ground transient recovery voltage immediately after the interruption | blocking start is the same as the above-mentioned case.

  Further, since hot gas enters the inside of the hollow insulating support cylinder 24, the space in the hollow insulating support cylinder 24 also contributes to the volume expansion of the temporary storage space 23 described above. That is, in addition to the space inside the shield 22, the space inside the hollow insulating support cylinder 24 is also a space for temporarily holding hot gas, and the space inside the shield 22 can be narrowed accordingly. For this reason, the ground tank 3 can be reduced in size, and the puffer-type gas circuit breaker 1 and the gas insulated switchgear can be reduced in size.

  Further, since the path for the hot gas to reach the periphery of the shield 22 becomes longer, the temperature of the hot gas when the hot gas reaches the periphery of the shield 22 can be lowered accordingly. In particular, in the present embodiment, the flow rate control unit 29 also serves as a heat exchanger, and a plurality of pleats 30 are provided on the inner wall surface of the hollow insulating support cylinder 24, so that the temperature of the hot gas can be lowered satisfactorily. . For this reason, the temperature rise around the shield 22 can be suppressed, and from this, the deterioration of the insulation between the shield 22 and the ground tank 3 can also be suppressed.

In the above description, the flow rate control unit 29 is provided in the gas blowing port 24a of the hollow insulating support cylinder 24, but the flow rate control unit 29 may be omitted. Further, although the plurality of pleats 30 are provided on the inner wall surface of the hollow insulating support cylinder 24, the pleats 30 may be omitted. Furthermore, instead of providing the slit 27 in the mounting bracket 26, a small hole is provided in the hollow insulating support cylinder 24 so that the inside of the hollow insulating support cylinder 24 can be a flow path 25 through which the CO ₂ gas 2 after cooling the arc 20 passes. .

  Further, in the gas insulated switchgear described above, both the securing of the temporary storage space 23 inside the shield 22 and the provision of the flow path 25 in the hollow insulated support cylinder 24 have been carried out. May be carried out only.

  Next, a third embodiment of the gas insulated switchgear according to the present invention will be described. The gas insulated switchgear of the present embodiment is different from the gas insulated switchgear of the first embodiment in the puffer type gas circuit breaker. A gas insulated switchgear according to this embodiment is shown in FIGS. In FIG. 5, the gas circuit breaker 1 of FIG. 2 is shown sideways. Moreover, the upper half part of FIG. 5 shows a state before blocking, and the lower half part shows a state after blocking.

The gas-insulated switchgear includes a fixed side electrode 4, a movable side electrode 5 that can be contacted and separated from the ground tank 3 filled with CO ₂ gas 2, a puffer cylinder 6 that is linked to the movable side electrode 5, A fixed piston 8 that forms a puffer chamber 7 between the puffer cylinder 6 and a CO ₂ gas 2 that surrounds the movable electrode 5 and is blown out from a blow-out port 9 provided on the side of the puffer cylinder 6 opposite to the fixed piston 8. A puffer-type gas circuit breaker 1 including an insulating nozzle 11 that leads to an opening gap 10 between the fixed side electrode 4 and the movable side electrode 5 is included, and the movable side electrode 5 is provided at the tip of the insulating nozzle 11. Is provided with an extension 31 surrounding the tip of the arc contact 4a of the fixed electrode 4 even when it is farthest from the fixed electrode 4.

At normal time, as shown in the upper half of FIG. 5, the fixed electrode 4 and the movable electrode 5 are in contact with each other, and, for example, a high-voltage current flows through these electrodes 4 and 5 and the puffer cylinder 6. The ground tank 3 is filled with CO ₂ gas 2 so that the electrodes 4 and 5 and the puffer cylinder 6 and the ground tank 3 are insulated.

When the movable side electrode 5 moves and leaves the fixed side electrode 4 due to the cutoff command, an arc 20 is generated between the arc contacts 4a and 5a of the electrodes 4 and 5 as shown in the lower half of FIG. To do. This arc 20 grows longer as the movable electrode 5 moves away from the fixed electrode 4. Also, the puffer cylinder 6 moves in conjunction with the movement of the movable electrode 5, and the CO ₂ gas 2 in the puffer chamber 7 is compressed by the fixed piston 8. The compressed CO ₂ gas 2 is blown from the blowing port 9 toward the separation gap 10 between the electrodes. The blown CO ₂ gas 2 is guided to the insulating nozzle 11 and flows into the separation gap 10 between the electrodes, and the arc 20 is cooled and extinguished.

Since the extension 31 is provided at the tip of the insulating nozzle 11, the CO ₂ gas 2 does not diffuse but flows around the arc 20 in the length direction of the arc 20 and passes through to the fixed side electrode 4 as it is. . That is, the hot gas heated by the cooling of the arc 20 does not diffuse but flows around the arc 20 in the length direction and passes through the fixed side electrode 4 as it is. For this reason, it is possible to prevent the hot gas generated by the cooling of the arc 20 from diffusing as it is from the separation gap 10 between the electrodes 4 and 5, and the hot hot gas immediately reaches the periphery of the shield 22. It is possible to prevent the surroundings of the shield 22 from becoming a high temperature at an early stage after the start of blocking. The shield 22 is a portion where the potential difference with the ground tank 3 is the largest and dielectric breakdown is likely to occur. Since dielectric breakdown is likely to occur due to a temperature rise, deterioration of insulation can be prevented by preventing the surroundings of the shield 22 from becoming high temperature. In particular, the voltage applied to the shield 22 rises transiently immediately after the start of interruption (ground transient recovery voltage), so that dielectric breakdown is more likely to occur. However, by providing the extension 31 at the tip of the insulation nozzle 11, hot hot It is possible to prevent the gas from immediately reaching the periphery of the shield 22 and to prevent the surroundings of the shield 22 from becoming a high temperature at an early stage after the start of the interruption. Insulation performance can be improved. Further, since the path for the hot gas to reach the periphery of the shield 22 becomes longer, the temperature of the hot gas when the hot gas reaches the periphery of the shield 22 can be lowered accordingly. For this reason, the temperature rise around the shield 22 can be suppressed, and the deterioration of the insulating property can also be suppressed from this.

Moreover, since the extension part 31 can cover from the insulating nozzle 11 to the tip of the arc contact terminal 4a of the fixed side electrode 4, the flow of the CO ₂ gas 2 during the shut-off process follows the arc 10 for a long time, The pressure in the extension part 31 can be increased. For this reason, arc extinction of the arc 10 can be made more reliable and the interruption performance can be improved.

  Next, a fourth embodiment of the gas insulated switchgear according to the present invention will be described. The gas insulated switchgear of the present embodiment is different from the gas insulated switchgear of the first embodiment in the puffer type gas circuit breaker. The gas insulated switchgear according to this embodiment is shown in FIGS. In FIG. 6, the gas circuit breaker 1 of FIG. 2 is shown sideways. Moreover, the upper half part of FIG. 6 shows a state before blocking, and the lower half part shows a state after blocking.

The gas-insulated switchgear includes a fixed side electrode 4, a movable side electrode 5 that can be contacted and separated from the ground tank 3 filled with CO ₂ gas 2, a puffer cylinder 6 that is linked to the movable side electrode 5, A fixed piston 8 that forms a puffer chamber 7 between the puffer cylinder 6 and a CO ₂ gas 2 that surrounds the movable electrode 5 and is blown out from a blow-out port 9 provided on the side of the puffer cylinder 6 opposite to the fixed piston 8. A puffer-type gas circuit breaker 1 including an insulating nozzle 11 that leads to an opening gap 10 between the fixed electrode 4 and the movable electrode 5 is included. An auxiliary blowing port 32 for generating a flow surrounding the insulating nozzle 11 by blowing _two gases 2 is provided.

  The auxiliary blowing port 32 is provided on the anti-fixed piston 8 side of the puffer cylinder 6 and is disposed outside the blowing port 9. A plurality of auxiliary blowing ports 32 are provided side by side in the circumferential direction so as to surround the insulating nozzle 11.

In the normal state, as shown in the upper half of FIG. 6, the fixed electrode 4 and the movable electrode 5 are in contact with each other, and, for example, a high-voltage current flows through these electrodes 4 and 5 and the puffer cylinder 6. The ground tank 3 is filled with CO ₂ gas 2 so that the electrodes 4 and 5 and the puffer cylinder 6 and the ground tank 3 are insulated.

When the movable side electrode 5 moves and leaves the fixed side electrode 4 due to the cutoff command, an arc 20 is generated between the arc contacts 4a and 5b of the electrodes 4 and 5 as shown in the lower half of FIG. To do. This arc 20 grows longer as the movable electrode 5 moves away from the fixed electrode 4. Also, the puffer cylinder 6 moves in conjunction with the movement of the movable electrode 5, and the CO ₂ gas 2 in the puffer chamber 7 is compressed by the fixed piston 8. The compressed CO ₂ gas 2 is blown from the blowing port 9 and the auxiliary blowing port 32. The CO ₂ gas 2 blown from the blow-out port 9 is guided to the insulating nozzle 11 and flows to the separation gap 10 between the electrodes 4 and 5 to cool the arc 20 and extinguish the arc. Further, the CO ₂ gas 2 blown from the auxiliary blowing port 32 forms an air curtain 33 that surrounds the insulating nozzle 11. For this reason, it is possible to prevent hot hot gas from staying between the main contacts 4b and 5b of the electrodes 4 and 5, and the temperature of this portion rises to cause dielectric breakdown between the main contacts 4b and 5b. Can be prevented from occurring.

In addition, the air curtain 33 prevents the hot gas from diffusing as it is from the separation gap 10 between the electrodes 4 and 5 and reaching the periphery of the conductor 21 immediately. Can be prevented from becoming hot. For this reason, it is possible to prevent the deterioration of the insulating property around the conductor 21 that is likely to cause dielectric breakdown, and in particular, it is possible to improve the insulation resistance against the ground transient recovery voltage immediately after the start of interruption. Further, the flow of the air curtain 33 is in the same direction as the flow of the CO ₂ gas 2 that cools the arc 20, and the stagnation of hot gas can be prevented to improve the cooling performance of the arc 20.

  Next, a fifth embodiment of the gas insulated switchgear according to the present invention will be described. In this gas insulated switchgear, the surface of an aluminum member having a higher potential than that of a grounding member is subjected to a turfram treatment. FIG. 7 shows a gas insulated bus of this gas insulated switchgear. The ground member is, for example, a ground sheath 34. However, the grounding member is not limited to the grounding sheath 34 of FIG. 7, and may be, for example, the grounding tank 3 of the first to fourth embodiments, the grounding member of the equipment constituting the gas insulated switchgear, or the like. The aluminum member is, for example, a gas-insulated bus bar conductor 43. However, the aluminum member is not limited to the conductor 43 of the busbar. For example, the conductor 21 of the first to fourth embodiments, the shield 22 of FIG. 4, and other aluminum members of equipment constituting the gas insulated switchgear. Etc.

The bus conductor 43 is accommodated in a grounding sheath 34 filled with CO ₂ gas 2. The surface of the conductor 43 is a coating layer 35 that has been subjected to a Tafram treatment (registered trademark of ULVAC TECHNO CORPORATION). Tafram treatment is based on hard anodized aluminum and aluminum alloy, and this hard anodized is impregnated with fluororesin. It has a very smooth and hard surface and is a highly functional composite integrated with the base material. This is a surface treatment technique capable of obtaining a chemical film. For this reason, the surface of the conductor 43 is densified, the electric field on the surface of the conductor 43 can be relaxed, and partial discharge and electron emission can be suppressed. For this reason, the insulation resistance performance of the conductor 43 can be improved. In addition, since the surface treatment of the conductor 43 does not cover the surface of the conductor 43 with a thick film, the coating layer 35 becomes thin, and deterioration of heat dissipation performance can be suppressed. For example, the dielectric strength of the separation gap 10 between the electrodes 4 and 5 can be improved by, for example, about 20% by subjecting the surface of the conductor 43 to a turfram process having a thickness of several tens of μm, for example.

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, (1) a mechanism for performing two-stage spraying relating to the embodiment of FIG. 1, (2) the conductor 21 in the ground tank 3 is surrounded by a shield 22, and hot gas generated at the time of shutting off inside the shield 22 is temporarily (3) An extension 31 surrounding the tip of the arc contact 4a of the fixed electrode 4 at the tip of the insulating nozzle 11 even when the movable electrode 5 is farthest from the fixed electrode 4 (4) A configuration in which a flow path 25 through which the CO ₂ gas after arc cooling passes is provided inside a hollow insulating support cylinder 24 that is fixed to the ground tank 3 and supports the 21 conductor, and (5) insulation. structure provided with CO ₂ auxiliary blowing port 32 to generate a flow surrounding the attached insulating nozzle 11 blows gas from the puffer chamber 7 around the nozzle 11, the potential compared to (6) grounding member (e.g., a ground sheath 34) May be carried out structure subjected to TUFRAM treatment on the surface of the high aluminum member (conductor 43 of the bus line), any one alone, may be performed in combination of two or more.

It is sectional drawing which shows 1st Embodiment of the gas insulated switchgear of this invention, and shows the principal part of the puffer-type gas circuit breaker. 1 is a schematic configuration diagram illustrating a first embodiment of a gas-insulated switchgear according to the present invention, partly cut away. It is a figure which shows the gas ejection characteristic of the puffer-type gas circuit breaker of FIG. 2 shows a second embodiment of the gas insulated switchgear of the present invention, and is a sectional view of the puffer type gas circuit breaker. FIG. It is sectional drawing which shows 3rd Embodiment of the gas insulated switchgear of this invention, and shows the waist | hip | lumbar part of the puffer type gas circuit breaker. It is sectional drawing which shows 4th Embodiment of the gas insulated switchgear of this invention, and shows the waist | hip | lumbar part of the puffer type gas circuit breaker. FIG. 9 is a cross-sectional view of a gas insulated busbar according to a fifth embodiment of the gas insulated switchgear of the present invention.

Explanation of symbols

1 puffer type gas circuit breaker 2 CO ₂ gas 3 grounded tank 4 fixed electrode 5 movable electrode 6 puffer cylinder 7 puffer chamber 7a first puffer chamber 7b second puffer chamber 8 fixed piston 9 outlet 10 separable gap DESCRIPTION OF SYMBOLS 11 Insulation nozzle 12 Partition wall 13 1st communicating port 14 2nd communicating port 21 Conductor 22 Shield 23 Space required in order to confine the hot gas produced at the time of interruption | blocking 24 Hollow insulation support cylinder 25 Channel 31 Extension part 32 Auxiliary blowing port 34 Busbar sheath 35 Coating (film) by taffram treatment
43 Busbar conductor

Claims (2)

A puffer chamber is formed in the grounded tank filled with CO ₂ gas between the fixed side electrode, the movable side electrode that can be brought into contact with and separated from the fixed side electrode, the puffer cylinder interlocked with the movable side electrode, and the puffer cylinder. A separation gap portion between the fixed side electrode and the movable side electrode for CO ₂ gas which surrounds the fixed piston and the movable side electrode and which is blown out from a blow-off port provided on the anti-fixed piston side of the puffer cylinder In the gas insulated switchgear including a puffer-type gas circuit breaker including an insulating nozzle that leads to the first, the puffer chamber is divided in series into at least two chambers, a first puffer chamber and a second puffer chamber, and the first puffer chamber The partition wall between the puffer chamber and the second puffer chamber has a first communication port that is always open, and a first opening that opens when the fixed electrode and the movable electrode are separated. 2 Communication port and is provided, a gas insulated switchgear, characterized in that ejecting from the outlet inwardly of said insulating nozzle jetted CO ₂ gas from the second puffer chamber to the first puffer chamber.   2. The gas insulated switchgear according to claim 1, wherein the surface of an aluminum member having a higher potential than that of the ground member is subjected to a tuffram treatment.

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