JPH04271249A - Compulsory air cooling type phase isolating bus - Google Patents

Abstract

PURPOSE:To materialize high cooling efficiency as a whole by making the most use of the compulsory cooling structure of the existing phase isolating main bus and the output terminal box of a generator and further performing the compulsory cooling of the neutral point short circuit bus box of the generator. CONSTITUTION:The output terminal box 1A-1C of each phase of the three phases of a generator and the second corresponding phase part of the neutral point short circuit bus of the generator are coupled with each other by individual ducts 4A-4C (or a common duct having a sealed partition between phases), and the blast port of a cooler is connected to the phase isolating main bus 3B of the central phase, and the suction port of the cooler is connected to the phase isolating main buses 3A and 3C of both-end phases. Additionally, a baffle, a grid 10, and an inverter 11, which adjusts the quantity of the air, are provided in the duct 4B of the central phase.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air-cooled phase separation busbar, and more particularly to an improvement in its cooling structure.

0003

[Background Art] With the increase in demand for electricity in recent years, the capacity of generators and transformers has become even larger. A forced air-cooled phase separation bus having a forced cooling structure is used as the phase separation main bus that connects the terminal boxes of the devices individually. In other words, in this forced air cooling type phase separation bus, a cooling device is connected to the phase separation main bus, and cooling gas is forcibly circulated by this cooling device, thereby cooling the phase separation main bus and the output terminal box of the generator. It cools the air with forced air. Generally, forced cooling air is sent from a cooling device to the phase separation main bus of both end phases, and this forced cooling air is collected at the output terminal box of the generator to the phase separation main bus of the central phase, and then It is returned to the cooling device through the phase main bus bar. In this case, the output terminal box of the generator is provided with a special return air guide in order to collect the forced cooling air into the central phase. Similarly, a return air guide is provided on the terminal box side of the transformer to collect forced cooling air to the phase separation main bus of the central phase.

[0004] Furthermore, as the capacity of transformers is increasing, the connection structure between transformers and generators is increasing.
Usually, two transformers are connected in parallel to one large capacity transformer. As a result, the neutral point short circuit busbar box of the generator has a relatively small capacity even though it is a heat generating part, so it is generally of a self-cooling type.

[0005]

However, as the capacity of generators is expected to increase in the future, it is expected that one large capacity transformer will be connected to one generator. In this case, the amount of heat generated in the neutral point short-circuited bus box of the generator increases significantly compared to the conventional case. Therefore, in the conventional forced air-cooled phase-separated bus in which the generator's neutral point short circuit bus box is self-cooled, it is no longer possible to sufficiently cool the neutral point short circuit bus box. It becomes necessary to cool it down. However, in response to such needs, it is difficult to forcibly cool the generator's neutral point short-circuit bus box separately and independently from the forced cooling of the phase-separated main bus and the generator's output terminal box. This is inconvenient as it increases the number of devices and makes the entire facility larger and more complex. In addition, special return air guides must be placed in the generator output terminal box and the transformer terminal box, which increases the number of components, which also increases the overall size of the equipment.・
This is a contributing factor to the complexity.

The present invention was proposed to solve the problems of the prior art, and its purpose is to utilize the existing forced cooling structure of the phase separation main bus and the output terminal box of the generator. Furthermore, the purpose is to perform forced cooling of the neutral point short-circuited bus box of the generator and to achieve high cooling efficiency as a whole. Another object of the present invention is to provide a forced air-cooled phase separation bus bar with excellent cooling efficiency, which can contribute to downsizing and simplifying the entire equipment by sharing such a cooling device. Another purpose is to make it possible to omit the return air guide, thereby further contributing to the downsizing and simplification of the entire equipment.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] The forced air-cooled phase separation busbar of the present invention has a central structure in which three-phase individual output terminal boxes arranged in parallel and three-phase parts arranged in parallel are collectively housed. A generator with a short-circuited bus box, a transformer with a terminal box, and a three-phase phase-separated main that connects the output terminal box of each of the three phases of the generator and the terminal box of the transformer individually. Forced air cooling of the phase separation main bus is achieved by sending cooling gas into the phase separation main bus through the bus and the air outlet, and recovering the cooling gas from within the phase separation main bus through the suction port. In a forced air-cooled phase separation bus with a cooling device, the output terminal box of each of the three phases of the generator and the corresponding phase part of the generator's neutral point short circuit bus box are sealed in individual ducts or between the phases. connected by a common duct having a partition, the air outlet of the cooling device is connected to the phase separation main bus of the central phase, and the inlet of the cooling device is connected to the phase separation main bus of both end phases. There is.

In this case, arc migration in the event that a ground fault occurs inside the individual ducts of the central phase or inside the central phase section of the common duct, inside the phase separation main bus bar or inside the output terminal box of the generator is prevented. Preferably, a baffle or grid is provided to prevent this.

[0010] Furthermore, it is desirable that a damper for adjusting the air volume be further provided inside the individual ducts of the central phase or inside the central phase portion of the common duct.

[0011]

[Operation] In the forced air cooling type phase separation bus of the present invention having the above-described configuration, the cooling gas blown from the cooling device first flows into the phase separation main bus of the central phase, and the phase separation bus of the central phase Forced air cooling is applied to the main separation bus. The cooling gas then flows into the central phase output terminal box of the generator to provide forced air cooling of the central phase output end bushing connection. Subsequently, the cooling gas passes through the duct, enters the center phase of the generator's neutral shorted bus box, is split within the neutral shorted bus box, and then flows to both ends of the neutral shorted bus box. The air flows towards the neutral point bushing connection and the neutral point short circuit bus bar. After this,
The cooling gas flows from both ends of the neutral short circuit bus box through the duct to the output terminal boxes of both end phases of the generator, and forces the output end bushing connections of both end phases to be cooled with forced air.
It flows into the phase separation main bus of both end phases, cools the phase separation main bus of both end phases with forced air, and finally returns to the cooling device.

As described above, in the present invention, the output terminal boxes of each of the three phases of the generator and the corresponding phase portions of the neutral point short circuit bus box are connected by ducts, and the connection relationship with the cooling device is By improving the simple structure of limiting, the existing forced cooling structure of the phase-separated main bus and generator output terminal box can be utilized to cool the phase-separated main bus, generator output terminal box, and neutral point short-circuit bus box. can be efficiently cooled by one cooling system. Additionally, the number of cooling devices can be reduced compared to the case where the forced cooling of the generator's neutral point short-circuit bus box is performed separately from the forced cooling of the phase-separated main bus and the generator's output terminal box. This is extremely advantageous because the entire equipment can be made smaller and simpler.

Furthermore, if a baffle or grid is provided inside the individual ducts of the central phase or inside the central phase section of the common duct, ground faults can be prevented inside the phase separation main bus or inside the output terminal box of the generator. If this occurs, the baffle or grid can prevent arc migration, thereby preventing progression to an interphase short circuit accident.

[0014] Furthermore, when placing a cooling device between the generator and the main transformer, it is generally placed so that the busbar length on the generator side is shortened. Most of the air flows out, making it impossible to balance the cooling characteristics of the phase-separated main bus on the generator side and the main bus on the transformer side. On the other hand, by installing a damper to adjust the air volume inside the individual ducts of the central phase or inside the central phase section of the common duct, the air volume can be divided almost equally between the generator side and the transformer side. Therefore, it is possible to balance the cooling characteristics of the phase-separated main bus on the generator side and the phase-separated main bus on the transformer side.

[0015]

[Embodiment] An embodiment (first embodiment) of a forced air-cooled phase separation bus bar according to the present invention will be described in detail below with reference to FIGS. 1 to 4. Note that FIG. 1 is a schematic side view showing the overall configuration of a forced air-cooled phase separation bus, and FIG. 2 is a side view showing details of the generator output terminal box, neutral point short circuit bus box, and cooling device in FIG. 3 are views in the direction of the X arrow in FIG. 2, and FIG. 4 is a view in the direction of the Y arrow in FIG.

First, as shown in FIGS. 1 and 2, an output terminal box 1 and a neutral point shorting bus box 2 are arranged side by side at the bottom of the generator G. The terminal box 30 of the transformer T is connected to the terminal box 30 of the transformer T via the phase-separated main bus 3. Further, reference numeral 4 in the figure indicates first to third ducts that connect the output terminal box 1 and the neutral point shorting bus box 2. As shown in FIG. 1, the phase separation main bus 3 is
The fourth and fifth ducts 5 and 6 are connected to an air outlet 8 and an inlet 9 of the cooling device 7, respectively. in this case,
From the perspective of FIG. 1, the fourth and fifth ducts 5 and 6 overlap, and the air outlet 8 and intake port 9 of the cooling device 7 also overlap, so these symbols are used in the figure. is also listed. Note that 12 in FIG. 1 is a connection boot that connects the fourth duct 5 and the air outlet 8 of the cooling device 7, and 13 is a connection boot that connects the fifth duct 6 and the intake port 9 of the cooling device 7. It is a connection boot that connects. These connecting boots 12
, 13 also overlap in this viewpoint, so these symbols are also shown in the figure. Also, 31
is a return air guide provided in the terminal box 30 of the transformer T on the transformer side.

More specifically, as shown in FIG. 4, the three-phase output terminal boxes 1A to 1C of the generator G are individually connected to the three-phase phase-separated main buses 3A to 3C on one side thereof. There is. According to the present invention, output terminal boxes 1A to 1 for each of the three phases are provided.
C and each corresponding phase portion of the neutral point short circuit bus box 2 are connected through first to third ducts 4A to 4C. Also,
A baffle or grid 10 and a damper 11 for adjusting the air volume are provided inside the second duct 4B of the central phase.

The air outlet 8 of the cooling device 7 is connected to the phase separation main bus 3B of the central phase through the fourth duct 5, and the suction port 9 of the cooling device is connected to the main bus 3B of the central phase through the fifth duct 6. It is connected to phase separation main buses 3A and 3C of both end phases. Furthermore, the cooling device 7 of this embodiment is configured to blow cooling air as a cooling gas.

In this embodiment having the above configuration, by operating the cooling device 7, forced cooling air 20 is generated in the cooling device 7 as shown in FIG. flows from the air outlet 8 of the cooling device 7 through the fourth duct 5 to the phase separation main bus 3, where it is forced air cooled, and then flows into the output terminal box 1 of the generator G where it is forced air cooled. do. This forced cooling air 20 then flows into the neutral point shorting box 2 of the generator G via the first to third ducts 4 and cools it with forced air. This forced cooling air 20 becomes forced cooling air on the return side within the neutral point short circuit box 2,
The air is returned to the output terminal box 1 of the generator G via the first to third ducts 4, where it is cooled by forced air. Furthermore, the forced cooling air 21 flows into the phase separation main bus bar 3 again, and after cooling it with forced air, finally passes through the fifth duct 6,
It returns to the inside of the cooling device 7 through the suction port 9.

To explain in more detail, the cooling air (cooling gas) in the cooling device 7 is first sent out as forced cooling air 20 from the air outlet 8, as shown in FIG. As shown in FIG. 4, the air flows into the central phase phase separation main bus 3B through the duct 5, and the central phase phase separation main bus 3B is forcedly cooled. As shown in FIG. 4, the forced cooling air 20 then flows into the output terminal box 1B of the central phase of the generator G to forcefully cool the output end bushing connection portion of the central phase. This forced cooling air 20 then flows into the output terminal box 1B of the central phase of the generator G, and cools the output end bushing connection portion of the central phase with forced air. This forced cooling air 20 is further transmitted from the center phase part of the neutral short circuit bus box 2 of the generator G to the neutral short circuit bus box 2 through the second duct 4B of the central phase.
to go into. The forced cooling air 20 is divided at the center phase part in the neutral point short circuit bus box 2, becomes forced cooling air 20A, 20C, and flows to both ends, forcing the neutral point bushing connection part and the neutral point short circuit bus bar. Wind chill.

The forced cooling air 20A, 20C becomes forced cooling air 21A, 21C on the return side at both ends of the neutral short circuit bus box 2. These forced cooling air 21A,
21C flows into the output terminal boxes 1A and 1C of both end phases of the generator G via the first and third ducts 4A and 4C of both end phases, respectively, and cools the output end bushing connection portions of both end phases with forced air. . The forced cooling air 21A, 21C further flows into the phase separation main busbars 3A, 3C of both end phases, respectively, and after cooling the phase separation main busbars 3A, 3C of both end phases with forced air, finally flows into the fifth duct. 6 and returns into the cooling device 7 via the inlet 9.

Further, on the transformer T side, the forced cooling air flows from the phase separation main bus 3B of the central phase to the terminal 30 of the transformer T.
The air is then branched off through the return air guide 31 and is supplied to the phase separation main buses 3A and 3C of both end phases.

As described above, in addition to the existing forced cooling structure for the phase-separated main bus and the output terminal box of the generator, this embodiment has the output terminal boxes 1A to 1C for each of the three phases of the generator G. The corresponding phase parts of the neutral point short circuit bus box 2 are connected by the first to third ducts 4A to 4C, and forced cooling air is sent to the phase separation main bus 3B of the central phase, and the phase separation main of both end phases is connected. By configuring it to be collected from busbars 3A and 3C,
Phase separation main busbars 3A to 3C and generator G output terminal box 1A to
1C and the neutral short circuit bus box 2 can be efficiently cooled by one cooling system. Also, compared to the case where the forced cooling of the neutral point short-circuited bus box 2 of the generator G is performed separately from the forced cooling of the phase separation main buses 3A to 3C and the output terminal boxes 1A to 1C of the generator G, Cooling device 7
This is extremely advantageous because the number of equipment can be reduced and the entire equipment can be made smaller and simpler.

Furthermore, in this embodiment, as shown in FIG.
Since a baffle or grid 10 is provided in the second duct 4B that connects the central phase part of the main bus bars 3A to 3C or the output terminal boxes 1A to 1C of the generator
In the event that an internal ground fault occurs, the baffle or grid 10 also has the advantage of preventing arc migration and preventing the progression to a phase-to-phase short circuit accident.

In addition, even if the cooling device 7 is arranged so that the busbar length on the generator G side is shortened, in this embodiment, the central phase output terminal box 1B and the neutral point short circuit busbar box 2
Since a damper 11 that adjusts the air volume is provided inside the second duct 4B that connects the central phase part of the generator, the air volume can be divided almost equally to the generator G side and the transformer T side. . Therefore, the cooling characteristics of the phase-separated main bus on the generator G side and the phase-separated main bus on the transformer T side can be balanced, and extremely efficient cooling can be achieved as a whole.

FIG. 5 is a front view showing another embodiment (second embodiment) of the forced air-cooled phase separation busbar according to the present invention. In this embodiment, output terminal boxes 1A to 1 for each of the three phases of the generator G are used.
The first to third ducts 4A to 4C connecting C and the corresponding phase part of the neutral short circuit bus box 2 of the generator G are U-shaped, and the first to third ducts 4A to 4C are , are arranged below the output terminal boxes 1A to 1C and the neutral point short circuit bus box 2. This embodiment has the advantage that the workability in assembling the output terminal box and the neutral point short circuit bus box can be significantly improved compared to the previous embodiment.

FIG. 6 is a diagram showing still another embodiment (third embodiment) of the forced air-cooled phase separation bus according to the present invention. In this embodiment, the first and third ducts 4A are U-shaped.
, 4C are arranged on the sides of the output terminal boxes 1A, 1C of both end phases and the neutral point short circuit bus box 2, and as in the second embodiment, the effect of significantly improving workability is obtained. It will be done.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the configuration and shape of the duct connecting the output terminal box of the generator and the neutral point short circuit bus box can be freely changed. , the specific connection method of each part can be freely selected. That is, in each of the above embodiments, separate three-phase ducts were used, but the invention is not limited to this, and for example,
It is also possible to use a three-phase integral common duct with a sealed partition, such as an aluminum plate, between the phases. Further, the cooling gas of the cooling device is not limited to air, and other gases may also be used.

[0029]

[Effects of the Invention] As described above, in the present invention,
Connect the output terminal box of each of the three phases of the generator to the corresponding phase part of the neutral point short circuit bus box of the generator with a duct, connect the air outlet of the cooling device to the phase separation main bus of the central phase, By simply improving the configuration by connecting the inlet of the cooling device to the phase separation main bus of both end phases, we can utilize the existing forced cooling structure of the phase separation main bus and the output terminal box of the generator. It is possible to perform forced cooling of the neutral point short-circuited bus box and achieve high cooling efficiency as a whole. By sharing such a cooling device, it is possible to provide a forced air-cooled phase separation bus with excellent cooling efficiency, which can contribute to downsizing and simplifying the entire equipment.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing the overall configuration of a first embodiment of a forced air-cooled phase separation bus according to the present invention.

FIG. 2 is a side view showing details of the output terminal box, neutral short circuit bus box, and cooling device of the generator in FIG. 1;

FIG. 3 is a view taken along the X arrow in FIG. 2;

FIG. 4 is a view along the Y arrow in FIG. 2;

FIG. 5 is a front view showing a second embodiment of the forced air-cooled phase separation busbar according to the present invention.

FIG. 6 is a plan view showing a third embodiment of the forced air-cooled phase separation busbar according to the present invention.

[Explanation of symbols]

G Generator T Transformer 1 (1A to 1C) Output terminal box 2 Neutral short circuit bus box 3 (3A to 3C) Phase separation main bus 4 (4A to 4C) First to third ducts 5 Fourth
duct 6 Fifth duct 7 Cooling device 8 Air outlet 9 Inlet 10 Baffle or grid 11 Damper 12, 13 connection boots 20 (20A, 20C), 21 (21A, 21C) Forced cooling air 30 Terminal box 31 Return air guide

Claims (3)

[Claims] [Claim 1] A generator equipped with three-phase individual output terminal boxes arranged in parallel and a neutral point short-circuit bus box formed by collectively housing three-phase parts arranged in parallel, and a terminal box. A three-phase phase-separated main bus that connects the equipped transformer, the output terminal box of each of the three phases of the generator, and the terminal box of the transformer individually, and cooling within the phase-separated main bus through the air outlet. In the forced air cooling type phase separation bus which has a cooling device that performs forced air cooling of the phase separation main bus by feeding the cooling gas and recovering the cooling gas from within the phase separation main bus through the suction port, the power generation The output terminal box of each of the three phases of the generator and the corresponding phase section of the neutral short circuit bus box of the generator are connected by individual ducts or a common duct with a sealed partition between the phases, and the cooling device air outlet is connected to the phase separation main bus of the central phase, and the inlet of the cooling device is connected to the phase separation main bus of both end phases. [Claim 2] The arc migration in the case where a ground fault occurs inside the phase separation main bus bar or inside the output terminal box of the generator is provided inside the individual ducts of the central phase or inside the central phase section of the common duct. 2. The forced air-cooled phase separation busbar according to claim 1, further comprising a baffle or a grid for preventing the phase separation. 3. The forced air-cooled phase separation busbar according to claim 1, further comprising a damper for adjusting air volume inside each of the individual ducts of the central phase or inside the central phase section of the common duct. .