GAS-INSULATED SWITCHGEAR APPARATUS

Abstract: A gas-insulated switchgear apparatus comprising two power-receiving units (A, E) with a cable head on power-receiving side, a wattage metering unit (MOF), and two lead-out units (B, D) with a cable head on lead-out side. The two power-receiving units (A, E) are arranged on one side of the wattage metering unit (MOF), and the two lead-out units (B, D) on the other side. The gas-­ insulated switchgear apparatus is thus simplified, electrical connection facilitated between the units, and the floor space of the whole apparatus reduced.

Description: BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a gas-insulated switchgear apparatus (hereinafter referred to as "GIS"), or more in particular to a configuration of GIS suitable for power-receiving equipment. DESCRIPTION OF THE PRIOR ART A conventional two-channel lead-in two-bank GIS for power receiving is introduced, for example, in "Electric Railways" Vol. 39, No. 9, at page l6, Fig. 4, and is shown in Fig. l accompanying this specification. In this skeleton diagram, the apparatus has an aligned-panel configuration comprising power-receiving units A, E including devices on lead-in wire side arranged in one box-like case containing a low-pressure insulating gas sealed therein for each channel, units B, D on lead-out side including devices connected with a transformer which are contained in one box-like case having a low-pressure insulating gas sealed therein, and a unit C with a wattage-metering instrument (hereinafter referred to as "MOF") involved contained in a single box-like case. A conventional GIS having this circuit configuration comprises the power-receiving units A, E on the outermost side, the lead-out units B, D at inwardly adjacent positions thereto, and the MOF unit C at the central part in an aligned configuration. The aforementioned configuration is also called a cubicle-type GIS generally. Among these devices, all the devices of the power-receiving units A, E and the lead-out units B, D are arranged in a gas-segmented box-like case as disclosed in JP-A-57-202805 and JP-A-59-l06809 as well known. For the power-receiving units A, E, in particular, the above-cited reference in its Table l at page l8, Japanese Utility Model Laid-Open No. 97l4/84 and Japanese Utility Model Laid-Open No. l075l3/84, disclose a configuration in which only circuit breakers such as a vacuum circuit breaker or a gas circuit breaker are arranged in the air section outside of the gas segments of the box-like case. Bushings and cable heads are used as insulation lead means for these units. Also, the MOF unit C includes an oil-filled or gas-insulated MOF l used in the box-like case, and is connected with the other units A, B, D and E. In the conventional aligned configuration in which the power-receiving units A and E are disposed on both sides with the lead-out units positioned inwardly thereof, however, the buses l0 and ll for connecting these two types of units are required to be extended through the MOF C. Further, the buses l0, ll are required to be connected with the MOF l by a bus l2, resulting in a large volume of the box-like case for sealing the insulating gas of the respective units. Also, the lead-in system on the power-receiving side generally includes a bushing or cable. The above-mentioned conventional GIS uses the former system, in view of the fact that the latter system, inspite of its advantages, leads to a problem of a larger floor space required. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a two-channel lead-in two-bank GIS configuration comprising power-receiving units, an MOF unit and lead-out units wherein electrical connection between these units are facilitated. Another object of the present invention is to provide a GIS configuration comprising power-receiving units, an MOF unit and lead-out units which is simplified thereby to reduce the whole floor space of installation. According to the present invention, there is provided a GIS configuration comprising two power-receiving units with cable head on the power-receiving or incoming side, an MOF unit, and two lead-out units with cable head on lead-out or outgoing side, in which the two power-receiving units are disposed on one side and the two lead-out units on the other side of the MOF unit. Generally, in this type of aligned-panel configuration, respective devices are housed to make up units in box-like cases of substantially the same height and depth. Nevertheless, the power-receiving side has a circuit breaker while the lead-out side has none of such a circuit breaker. The configuration according to the present invention with the power-receiving units placed adjacently to each other simplifies both the bus connecting the units and the construction in the box-like case on the lead-out side. As a result, the floor space required for the whole system is reduced, or in the best case, the floor space required for the lead-out units is reduced to almost one half as compared with the conventional configurations. BRIEF DESCRIPTION OF THE DRAWINGS Fig. l is a skeleton diagram showing a circuit configuration of a conventional gas-insulated switchgear apparatus. Fig. 2 is a skeleton diagram showing a circuit configuration of a gas-insulated switchgear apparatus according to the present invention. Fig. 3 is a plan view showing a gas-insulated switchgear apparatus according to an embodiment of the present invention realized with the circuit configuration of Fig. 2. Fig. 4 is a front view of the circuit configuration shown in Fig. 3. Fig. 5 is a longitudinal sectional view taken along the line V-V in Fig. 4. Fig. 6 is a longitudinal sectional view taken along the line VI-VI in Fig. 4. Fig. 7 is a longitudinal sectional view taken along the line VII-VII in Fig. 4. Fig. 8 is a plan view showing a gas-insulated switchgear apparatus according to the another embodiment of the present invention. Fig. 9 is a front view of the apparatus shown in Fig. 8. Fig. l0 is a longitudinal sectional view taken along the line X-X in Fig. 9. DESCRIPTION OF THE PREFERRED EMBODIMENTS A GIS according to the present invention will be described below with reference to the embodiments shown in the accompanying drawings. As shown in a skelton diagram of a GIS in Fig. 2, two power-receiving units A, E each include, almost in the same manner as in the conventional configurations, a cable head, and a circuit breaker 2 with disconnectors 3, 7 on the sides thereof, and these units A and E are arranged in adjacent relationship with each other and connected by a bus l0. The power-receiving units A and E are disposed only on one side (left side in the drawing) of an MOF unit C with an MOF l housed therein, and are connected to the MOF l by a bus l2a. The lead-out units B, D each also include, substantially in the same manner as in the conventional configurations, a disconnector 5 and a cable head 6. These two units B and D are disposed adjacently to each other and are connected by a bus ll. These lead-out units B and D are arranged unilaterally on the other side (on the right side in the drawing) of the MOF unit C and are connected to the MOF l by a bus l2b. Consequently, in the GIS according to the present invention wherein the power-receiving units A, E and the lead-out units B, D are concentrated on the left and right sides of the MOF unit C respectively, the units A and E or the B and D in adjacent relationship with each other respectively are connected in simplified way, and so are the connections of each of these units and the MOF unit C. By thus simplifying the connections between the units A to E, the construction of the apparatus is also simplified and reduced in size, thereby reducing the floor space occupied by the whole GIS. The buses l2a, l2b of the MOF unit C, depending on whether MOF l is of oil-filled or gas-insulated type, may take the form of ordinary air bus or, as shown by the two-dot chain, a gas-insulated bus as desired. As shown in the plan view of Fig. 3 and the front view of Fig. 4, the units A to E of the above-described GIS are aligned from left to right in box-like cases, whereby the power-receiving and lead-out side devices may be concentrated thereby to achieve the above-mentioned superior effect. The power-receiving unit A (the same applies to unit E) in the aforementioned aligned configuration will be explained with reference to Fig. 5, and the lead-out unit B, D with Figs. 6 and 7. The power-receiving unit A, as shown in Fig. 5, has the box-like case 20 segmented by a partition 22 into a door-side air chamber 20a and a deep chamber, which in turn is divided into two upper and lower hermetic chambers 20b, 20c and an air chamber 20d by means of two partitions 23, 24. These hermetic chambers 20b, 20c are sealed with an insulating gas like SF₆ under a pressure of about l kg/cm². The partition 22 has mounted thereon a pair of bushings 25 protruded into the hermetic chambers 20b, 20c. The bushing 25 is connected to a circuit breaker 2 arranged in the air chamber 20a, and the other side of the bushing 25 to a cable head 4 and the bus l0 through disconnectors 3, 7 in the hermetic chambers 20b, 20c respectively. The bus l0 leads to the MOF l as shown in Figs. 2 and 3, while the cable head 4 is connected to the transmission line through the cable 9 in the air chamber 20d. The lead-out units B, D are configured in the manner shown in Figs. 6 and 7. Specifically, one lead-out unit B has a box-like case 30 with a door 3l, as shown in Fig. 6, which is segmented into an upper hermetic chamber 30a sealed with an insulating gas and a lower air chamber 30b. The hermetic chamber 30a has arranged therein a disconnector 5a connected to the bus ll leading to the MOF l and a cable head 6a on the door 3l side. The cable head 6a is led outside by being connected with the cable 33 on the air room 30b side. The other lead-out unit D, by contrast, as shown in Fig. 7, has a box-like case 40 with a door 4l, which is segmented by a substantially L-shaped partition 42 into a hermetic chamber 40a sealed with an insulating gas and an air chamber 40b around the two sides of the substantially L-shaped partition 42. This hermetic chamber 40a has arranged therein, as in the previously-described case, a disconnector 5b connected to the bus ll and a cable head 6b of the door 4l, which cable head 6b is connected to a cable arranged in the air room 30b. The style of the hermetic chamber 40a formed in the box-like case 40 may be changed as desired, and the position of the cable head 6b may also be adjusted appropriately. The MOF unit C interposed between the power-receiving units A, E and the lead-out units B, D is formed of a box-like case of the same height and depth as the remainders taking the aligned configuration into consideration, and has arranged therein the MOF l of oil-filled or gas-insulated type, in such a manner that this particular unit is not desirably much different from the other units. The units A to E, which are formed in the manner mentioned above, are configured in alignment as shown in Figs. 3 and 4, with the power-receiving units A, E and the lead-out units B, D centralized respectively on the two sides of the MOF unit C. As a result, external connection and electrical connection between the units are simplified. Another embodiment of GIS according to the present invention is shown in Figs. 8 and 9. In this embodiment, the power-receiving units A, E and the MOF unit C are arranged in the same configuration as the preceding embodiment. The lead-out units B, D, however, are collectively arranged in the manner described below. Specifically, the lead-out units arranged on the right side of the MOF unit C, as shown in Fig. l0, has a box-like case 50 with a door 5l, which are segmented into two upper and lower hermetic chambers 50a, 50b sealed with an insulating gas and an air chamber 50c by substantially horizontal partitions 52, 53. The lead-out unit B is formed by use of the upper hermetic chamber 50a, and the lead-out unit D by use of the lower hermetic chamber 50b. The upper hermetic chamber 50a making up the lead-out unit B has arranged therein a disconnector 5a and a cable head 6a, and is connected to the MOF l through the bus ll. The hermetic chamber 50b making up the lead-out unit D, on the other hand, has arranged therein a disconnector 5b and a cable head 6b. For electrical connection of the units B and D, a bushing 54 is mounted on the pertition 52, by use of which the disconnectors 5a and 5b are connected to each other, so that the lead-out unit D is connected to the MOF l through the bus ll. Each of the cable heads 6a, 6b is connected with cables 55, 56 respectively in the air chamber 50c, and lead to a transformer and the like not shown. Although the upper and lower hermetic chambers 50a and 50b are defined by the partitions 5l and 52 in this embodiment, these hermetic chambers may alternatively be communicated to each other by gas. In this way, by arranging the power-receiving units A, E and the lead-out units B, D on the sides of the MOF unit C collectively respectively, the buses for connecting the power-receiving units A and E, or the MOF unit C and the power-receiving units A, E, may be laid without passing through the box-like cases of the lead-out units B, D. As a consequence, the interior construction of the box-like case 50 making up the lead-out units B, D is simplified, with the two lead-out units B and D housed therein in double stages as shown in Fig. l0. The two power-receiving units A and E are configured on one side of the MOF unit C, and the two lead-out units B and D are arranged in two upper and lower stages within one box-like case on the other side of the MOF unit C, so that the buses for connecting the power-receiving units to each other and for connecting the power-receiving units and the MOF unit are simplified. At the same time, the floor space required for the lead-out units is reduced thereby to render the whole GIS less bulky. According to the embodiments described above, the two power-receiving units are arranged on the left side and the two lead-out units on the right side of the MOF unit to make up a GIS. The units on the right and left side of the MOF unit arranged as above, however, may be replaced with each other with equal effect. Also, the arrangement of the parts of the power-receiving units and the lead-out units may be changed appropriately. According to the present invention, there is provided a GIS configuration for simplifying the connection of two power-receiving units and also buses and the MOF unit to each other in an aligned construction, and therefore the floor space required for the whole apparatus is also reduced.

Claims: A gas-insulated switchgear apparatus comprising two power-receiving units (A, E) with a cable head on power-receiving side, a wattage metering unit (MOF), and two lead-out units (B, D) with a cable head on lead-out side, each including a box-like case (20, 30, 40, 50) characterized in that said two power-receiving units (A, E) are arranged on one side of said wattage metering unit (MOF), and said two lead-out units (B, D) on the other side of said wattage metering unit (MOF). A gas-insulated switchgear apparatus according to Claim l, characterized in that each of said lead-out units (B, D) juxtaposed on the other side of said wattage metering unit (MOF) includes an independent box-like case (30, 40). A gas-insulated switchgear apparatus according to Claim l, characterized in that each of said lead-out units (B, D) arranged on the other side of said wattage metering unit (MOF) includes a single box-like case (50) segmented into a plurality of chambers (50a, 50b, 50c). A gas-insulated switchgear apparatus according to Claim l, characterized in that said two lead-out units (B, D) include upper and lower hermetic chambers (30a, 30b; 40a, 40b; 50a, 50b) sealed with an insulating gas in a single box-like case. A gas-insulated switchgear apparatus according to Claim l, characterized in that each of said lead-out units (B, D) includes a single box-like case (30, 40) segmented into upper and lower hermetic chambers (30a, 30b; 40a, 40b) sealed with an insulating gas, each having arranged therein a disconnector (5a, 5b), the end on this side of said disconnector (5a, 5b) being connected to a cable head (6a, 6b), the end on far side of each disconnector (5a, 5b) being connected to a bus (11) at the far and upper part. A gas-insulated switchgear apparatus according to Claim 1, characterized in that each of said power-receiving units (A, E) includes a circuit breaker (2) vertically arranged in an air chamber (20a) on door side of a box-like case (20) segmented by partitions (22, 23, 24), a disconnector (7) in an upper hermetic chamber (20b) of the box-like case (20) sealed with an insulating gas and connected to the bus side of said circuit breaker (2), and a disconnector (3) arranged in the lower hermetic chamber (20c) of said box-like case (20) and sealed with an insulating gas and connected to the cable head side of said circuit breaker (2).

Inventors: OISHI, KAZUAKI, OKUMURA, KIYOSHI
Applicants: HITACHI, LTD.
Application year: 1987
Main classification: H02B13
IPC codes: H02B7, H02B13