JPH0528897Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a forced air-cooled phase-separated busbar with switching equipment connected in between and used for power transmission between a generator and a main transformer. .

[Conventional technology]

Conventionally, the capacity of phase-separated buses has increased as generator capacity has increased, and as a countermeasure, a method has been used to force cooled air to flow inside the bus to keep the temperature rise of the bus below a limit value. It will be done. As shown in Japanese Patent Publication No. 56-25853, this cooling method involves blowing air into the space between the conductor and the outer sheath of the busbars at both ends of the three-phase busbars, and There is a method in which the air passes through a three-phase inter-phase air duct installed in the vessel and is folded back between the intermediate jacket and the conductor. Another method is to send air to the space between the outer sheath and the conductor for each of the three phases, and use the space inside the hollow conductor of each phase as the air path when turning. In addition, in recent power generation main circuits, as shown in Fig. 2, a generator breaker 4 is installed midway through the phase separation bus 3 connecting the generator 1 and the main transformer 2, and a generator breaker 4 is installed in the middle of the phase separation bus 3 connecting the generator 1 and the main transformer 2. Instead, a circuit is used in which the generator circuit breaker 4 connects and disconnects the generator 1 to the system, and at the same time always supplies power for the substation's in-house equipment via the in-station transformer 6. A lot of things happened. Therefore, phase separation bus 3
It has become necessary to install the generator circuit breaker 4 in the middle of the process, and to consider a total cooling system that includes the generator circuit breaker 4. Conventionally, switching equipment such as the generator circuit breaker 4 has only a space between the jacket and the conductor as a cooling air path, and there is no space corresponding to the space inside the hollow conductor of the phase separation bus 3, so generally A cooling system with a configuration as shown in FIG. 3 is adopted.

In the figure, the phase separation bus 3 consists of a jacket 3a and a hollow conductor 3b. The generator circuit breaker 4 installed in the middle part of the phase separation bus 3 consists of a jacket 4a and an arc-extinguishing chamber/conductor part 4b. Main transformer 2
and the generator 1 are connected by a conductor 3b and a flexible conductor 3c of a phase separation bus 3, respectively. Further, the arc extinguishing chamber/conductor portion 4b of the generator circuit breaker 4 and the conductor 3b of the phase separation bus bar are also connected by a flexible conductor 3c. Cooling air inlets 7a and 7c are provided on both end phase generator 1 sides of the phase separation bus 3, and a cooling air outlet 8 is provided on the middle phase generator 1 side. A cooling device 10 that sends out cooling air includes a blower 11 and a cooler 12.

With the above configuration, the blower 11 of the cooling device 10
After being cooled by a cooler 12, the air sent out by The flow is diverted and flows in. Then, after passing through the space between the outer cover 3a and the conductor 3b of the phase separation bus 3, and passing through the space between the outer cover 4a of the generator circuit breaker 4 and the arc extinguishing chamber/conductor 4b, the phase separation bus 3
The cooling air that is turned back at the end on the main transformer 2 side and collected in the middle phase flows in the opposite direction in the same way as above, and is passed through the cooling air outlet 8 at the end of the middle phase on the generator 1 side to the cooling device 10. will be returned to.

Therefore, the temperature of the cooling air at the generator circuit breaker 4 of both end phases is warmed by the heat generated by the phase separation bus 3 from the cooling air inlets 7a and 7c to the generator circuit breaker 4, and is higher than the temperature at the inlet. ing. In addition, in the mid-phase generator breaker 4, the cooling air heated by the heat generated over the entire length of both end phases has an air volume twice that of the end phase, and flows from the folded part of the mid-phase to the generator breaker 4. Cooling air whose temperature has further increased due to the heat generation of the phase separation bus 3 up to this point flows in.

[Problem that the invention attempts to solve]

Since the conventional forced air cooling type phase separation bus is configured as described above, the temperature of the cooling air flowing into the switchgear is increased by the phase separation bus from the cooling air inlet to the switchgear. The conditions were harsh for both. In addition, in general, the heat-generating part of a phase-separated busbar is directly cooled by cooling air, but SF ₆
Heat-generating parts such as contacts in switching devices such as gas circuit breakers cannot be cooled directly by cooling air due to their structure, so cooling efficiency is poor, and cooling air or cooling air with a lower temperature than the phase separation bus bar is used. In many cases, faster cooling air is required. Therefore, in order to satisfy this requirement, it became necessary to flow a larger amount of cooling air than if switching equipment was installed, which led to the increase in the capacity of the blower and cooler, causing problems such as impairing the economic efficiency of the plant. .

This idea was made to solve the problems mentioned above, and by installing a switching device in the middle, a low-cost cooling device can be used to raise the specified temperature of each device without increasing the amount of cooling air. The purpose of this study is to obtain a forced air-cooled phase separation bus that satisfies the above values.

[Means for solving problems]

The forced air-cooled phase separation bus according to this invention has a cooling air inlet close to the switching equipment of both end phases, and a first flow from the cooling air inlet to the switching equipment of both end phases and the phase separation bus of both end phases. A second channel, which is connected to the intermediate phase separation bus bar and the switching equipment, and forms the return route of the first channel.
and a third flow path through which the cooling air from the second flow path flows to the other three-phase phase separation bus.

[Effect]

In this invention, low-temperature cooling air flows to the switching equipment that has the most severe temperature rise restrictions.

〔Example〕

FIG. 1 shows an embodiment of this invention, and since the overall configuration in the figure is the same as that in FIG. 3, only the differences from FIG. 3 will be explained. Reference numerals 9a and 9b are cooling air inlets, which are provided close to the generator circuit breakers 4 at both end phases of the phase separation bus 3. A bushing 14 is provided in a portion closer to the generator 1 than the cooling air inlets 9a and 9b of both end phases, and
Blocking the flow to the side. The interphase duct 15, which is provided by connecting the middle phase and both end phases, is used to return the cooling air turned back from both end phases from the middle phase to both end phases. It is adjustable for balance. The end of the phase separation bus 3 on the generator 1 side is covered with a jacket 3a.
The cooling air flowing through the space between conductor 3b and conductor 3b
The end of the conductor 3b is open so that it can be folded back through the hollow part of the conductor 3b. An outlet 13 for cooling air from each phase is provided, and the end of the conductor 3b on the generator circuit breaker 4 side is closed, so that the cooling air flows out from the outlet 13.

With the above configuration, the blower 1 of the cooling device 10
1. The cooling air that has passed through the cooler 12 is divided into cooling air inlets 9a and 9b provided at both end phases near the generator circuit breaker 4 along the flow shown by the arrow, and flows into the phase separation bus 3. The inflowing cooling air passes through the space between the sheath 3a of the phase separation bus 3 of both end phases and the conductor 3b, and immediately flows into the space between the sheath 4a of the generator circuit breaker 4 and the arc extinguishing chamber/conductor 4b and the main transformer. A first flow path 2 consisting of a space between the outer sheath 3a and the conductor 3b at both end phases on the vessel 2 side
Flows to 1. After that, it is folded back at the end on the main transformer 2 side, and the cooling air flows into the second flow path 22 between the middle phase conductor 3b and the jacket 3a and between the middle phase jacket 4a and the arc extinguishing chamber/conductor 4b. After flowing in the same manner as above, the cooling air flows from the third flow path 23, that is, from the middle phase on the generator 1 side to the interphase duct 15, into the space between the outer sheath 3a and the conductor 3b of both end phases as well. The air flows in such a way that the air volume is balanced, and is turned back into the inside of the conductor 3b at the end on the generator 1 side. After that, the air flows out from the cooling air outlet 13 and is returned to the cooling device 10 again.

As a result of the above, the distance from the cooling air inlets 9a, 9b to the generator circuit breaker 4 is almost reduced.
The cooling air flows to the generator circuit breakers at both end phases with almost no temperature rise, and the middle phase generator circuit breakers also slide by the reduction in temperature rise of the cooling air at the end phases compared to conventional systems. As a result, low-temperature cooling air flows.

Also, regarding the cooling of the phase separation bus 3 between the generator breaker 4 and the generator 1, the jacket 3a of each phase and the conductor 3
Since both the space between the conductor 3b and the space inside the conductor 3b are cooled, efficient cooling is possible, and even relatively high temperature cooling air near the midpoint of the cooling air path can be sufficiently suppressed to below the temperature rise limit. It is possible.

[Effect of idea]

As described above, according to this invention, by providing the cooling air inlet close to the opening/closing equipment, the temperature rise of the cooling air flowing into the opening/closing equipment can be kept as low as possible, and even if Since it is possible to efficiently cool the harsh opening/closing equipment section, it can be handled with a low-cost cooling device without unnecessarily increasing the amount of cooling air.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view of an embodiment of this invention.
FIG. 2 is a wiring diagram of a conventional phase separation bus, and FIG. 3 is a schematic vertical cross-sectional view of a conventional forced air-cooled phase separation bus. 3...Phase separation bus bar, 3a...Sheath, 3b...Conductor, 4...Generator circuit breaker (switching equipment), 9a, 9
b...Cooling air inlet, 15...Interphase duct, 21,
22, 23...first, second, and third flow paths. In addition,
In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Switching equipment installed in the middle of three-phase phase separation busbars, cooling air inlets installed close to the switching equipment on both end phases, and this cooling air. a first flow path leading from the inlet to the switching devices of both end phases and the phase separation bus of both end phases; and a return path of the first flow path leading from the inlet to the phase separation bus of the middle phase and the switching device of the middle phase. and a second flow path between the jacket and the conductor for each phase of the remaining portion of the three-phase phase separation bus bar not including the switching equipment, and a return path within the conductor; A forced air cooling phase comprising a third flow path through which the cooling air passes through the flow path, and a cooling air outlet that connects from the inside of the conductor to the outside of the jacket, which is the end of the third flow path. Separate busbar. (2) A forced air-cooled phase separation bus bar according to claim 1 of the utility model registration claim, which is provided with a third flow path that communicates between the phase separation bus bars of the middle phase and both end phases through an interphase duct.