JPH0636314U - Gas insulated switchgear - Google Patents

Abstract

(57) [Abstract] [Purpose] To be able to perform both DC withstand voltage test of cables and AC withstand voltage test of gas insulated switchgear without gas treatment. [Structure] A test disconnector TDS is provided between a line side disconnector LDS and a cable head CHD. A test terminal TCHD to which a test cable can be connected from the outside is provided, and the test terminal TCHD is connected to a circuit between the line-side disconnector LDS and the test disconnector TDS.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas-insulated switchgear installed in an electric station such as a substation.

[0002]

[Prior art]

 The gas-insulated switchgear used for pulling in the power cable has at least a busbar conductor, a busbar-side disconnector, a circuit breaker, and a line-side disconnector, and the busbar conductor passes through the busbar-side disconnector. Is connected to one end of the circuit breaker, and the other end of the circuit breaker is connected to the cable head via the line side disconnector.

FIG. 5 shows, as an example, a configuration example of a gas-insulated switchgear used for pulling in a power cable in an electric station having a double bus line structure. In the figure, BUS1 and BUS2 are respectively Bus lines and O-bus lines, DS11 and DS12 are respectively the A-bus line side disconnectors and O-bus line side disconnectors, CB is a circuit breaker, LDS is a line side disconnector, and CHD is a cable head for connecting power cables. The busbars BUS1 and BUS2 are connected to one end of the circuit breaker CB via the busbar side disconnectors DS11 and DS12, respectively, and the other end of the busbar CB is connected to the cable head CHD via the line side disconnector LDS. There is.

ES1 and ES2 are grounding switches for grounding one end and the other end of the circuit breaker CB, LES is a cable head and a line side grounding switch for grounding a power cable, and LPT is a cable head CHD. And a line side disconnecting switch LDS, which is a transformer for measuring a line voltage connected to a circuit connecting the disconnecting switch PDS and the line side disconnecting switch LDS. TCHD is a test terminal, which is derived from the circuit between the cable head CHD and the line-side disconnector LDS.

[0005] The above each device are either SF ₆ gas is housed in a common container which is sealed, or is housed in appropriately divided into a plurality of vessel SF ₆ gas is sealed. A terminal of a power cable PC is connected to the cable head CHD, and in this example, a current transformer CT is mounted near the terminal of the cable.

In the conventional gas-insulated switchgear shown in FIG. 5, the test terminal TCHD has a structure similar to that of a slip-on type cable head (configured so that the end of the test cable can be freely connected and disconnected). The opening that connects the end of the cable is normally closed with a lid.

When performing a DC withstand voltage test on a cable, the lid that closes the opening of the test terminal TCHD is removed, and as shown in FIG. 6, the test cable TC is attached to the test terminal TCHD. , The line side disconnecting switch LDS, the line side grounding switch LES, and the disconnecting switch PDS are open, and the test DC power supply TDC to the test cable TC, the test terminal TCHD, and the cable head CHD. Apply a DC voltage for testing to the power cable PC through and.

[0008]

[Problems to be solved by the device]

 In the conventional gas-insulated switchgear shown in FIG. 5, since the test terminal TCHD is connected to the power cable PC through the cable head CHD, the AC circuit of the switchgear circuit part composed of the circuit breaker and the switchgear is connected. When a test AC voltage is applied through the test terminal TCHD to perform a voltage test, the test voltage is also applied to the power cable PC having a large capacitance, and a large charging current flows. Therefore, it is necessary to prepare a power supply for the AC withstanding voltage test that has a remarkably large capacity, but in reality it is impossible to prepare such a large-capacity test power supply.

Therefore, conventionally, after collecting the gas in the portion of the gas-insulated switchgear where the bus BUS1 or BUS2 is stored, an AC withstanding voltage test terminal is connected to the bus, and then the gas is supplied again. An AC withstand voltage test was conducted by filling and applying a test AC voltage to the switch circuit through the AC withstand voltage test terminal with the line-side disconnector LDS open. Therefore, after the AC withstanding voltage test was completed, it was necessary to recover the gas for the busbar portion again, remove the test terminals, then remove the AC withstanding voltage test terminals, and then refill the gas.

As described above, conventionally, it was necessary to perform gas treatment (collection and refilling of gas) when performing an AC withstanding voltage test, so that there was a problem that the withstanding voltage test requires much labor. .

An object of the present invention is to enable a DC withstand voltage test of a power cable and an AC withstand voltage test of a switch circuit through a test terminal to which a test cable can be connected from the outside. Another object of the present invention is to provide a gas insulated switchgear.

[0012]

[Means for Solving the Problems]

 The present invention is a gas insulation system in which a busbar conductor is connected to one end of a circuit breaker via a busbar-side disconnector, and the other end of the circuit breaker is connected to a cable head for power cable connection via a line-side disconnector. It relates to a switchgear.

In the present invention, a test disconnector is provided between the line-side disconnector and the cable head, and a test terminal to which a test cable can be connected from the outside is provided. It was connected to the circuit between the line-side disconnector and the test disconnector.

[0014]

[Action]

 As described above, a test disconnector is provided between the line side disconnector and the cable head, and a test terminal to which a test cable can be connected from outside is provided, and the test terminal is connected to the line side disconnector. Connected to the circuit between the switch and the test disconnector, open the line-side disconnector and close the test disconnector, and apply a DC test voltage through the test terminals to apply the test DC voltage to the power cable. A DC withstand voltage test can be performed. Further, by applying a test AC voltage through the test terminal with the test disconnector opened, an AC withstanding voltage test of the switch circuit portion can be performed.

As described above, according to the present invention, the DC withstand voltage test of the power cable and the AC withstand voltage test of the switch circuit portion are performed by using the test terminal to which the test cable can be connected from the outside. Since it is possible to perform both of the above, it is possible to efficiently perform the DC withstand voltage test and the AC withstand voltage test without requiring gas treatment during the test.

[0016]

【Example】

 FIG. 2 shows an electrical configuration of an embodiment of the present invention. In the figure, BUS1 and BUS2 are respectively Kobusen and Otobus, DS11 and DS12 are Kobuson side disconnector and Otobus side disconnector, respectively. CB is a circuit breaker, LDS is a line side disconnector, CHD is a power cable connecting cable head, ES1 and ES2 are grounding switches for grounding one and the other ends of the circuit breaker CB, respectively, and LES is a cable head and a power cable. The line side grounding switch for grounding the line, the LPT is an instrument transformer for line voltage measurement, which is connected to the line side terminal of the line side disconnector LDS via the disconnector PDS. It is constructed similarly to the conventional one shown in FIG.

In the present invention, the test disconnector TDS is provided between the line side disconnector LDS and the cable head CHD, and the test terminal TC HD to which the test cable can be connected from outside is connected to the line side disconnector. It was connected to the circuit between the LDS and the test disconnect TDS.

FIG. 1 shows an example of the structure of the gas-insulated switchgear according to the present embodiment. In FIG. 1, 1 is an operator box also serving as a base, and 2 is supported on the operator box 1. It is a cylindrical breaker container. Branch pipe portions 2a and 2b are provided on the side surface of the container 2 with a vertical space therebetween, and busbar containers 5 and 6 are connected to the branch pipe portions 2a and 2b via insulating spacers 3 and 4, respectively. .

A gantry 7 is arranged on the side of the controller box 1, and a cylindrical line-side unit container 8 is supported on the gantry 7. A branch pipe portion 8a is provided on the upper side surface of the container 8, and the branch pipe portion 8a is connected to a branch pipe portion 2c provided on the upper side surface of the circuit breaker container 2 via an insulating spacer 9.

On the side surface of the line-side unit container 8, branch pipe parts 8b and 8c are provided at intervals in the vertical direction, and an instrument transformer container 11 is connected to the branch pipe part 8b via an insulating spacer 10. Has been done. The branch pipe portion 8c is closed by a cover plate 12, and test terminals TCHD for three phases are attached to the cover plate 12.

The circuit breaker CB and the earthing switches ES1 and ES2 are stored in the circuit breaker container 2 in three phases, and the busbars 5 and 6 respectively form the former bus BUS1 and the second bus BUS2. A busbar conductor and busbar-side disconnectors DS11 and DS12 are housed.

The conductors forming the busbars BUS1 and BUS2 are connected to one end of the circuit breaker CB through the busbar side disconnectors DS11 and DS12, the penetrating conductors of the insulating spacers 3 and 4 and the connecting conductors 13 and 14, respectively.

A cable head CHD for three phases is attached to the bottom of the line-side unit container 8, and a line-side disconnector LDS and a line-side grounding switch LES are arranged above the cable head. There is. One end of the line-side disconnector LDS is connected to the other end of the circuit breaker CB through the penetrating conductor of the insulating spacer 9 and the connecting conductor 15. The other end of the line side disconnector LDS is connected to the cable head CHD via the connection conductor 16 and the test disconnector TDS, and the line side grounding switch LES is provided between the connection conductor 16 and the ground. ing.

An instrument transformer LPT is housed in the instrument transformer container 11, and the terminals of the instrument transformer pass through the through conductor of the insulating spacer 10, the connecting conductor 17, and the disconnector PDS to the line side disconnector LDS. Is connected to the other end of.

The test terminal TCHD is composed of a slip-on type cable head to which the end of the test cable can be detachably connected from the outside, and each cable connection portion is always closed by the lid 18. It has become. The test terminal of each phase is connected to the circuit between the test disconnector TDS and the line side disconnector LDS through the connection conductor 19.

In the operation device box 1, an operation device 21 for the circuit breaker CB, an operation device for the grounding switches ES1 and ES2 (not shown), and a control panel 20 are housed, and each operation device is appropriately installed. It is connected to the operating shaft of the corresponding device via the connecting mechanism of.

A three-phase power cable PC is erected inside the gantry 7 from the underground cable pit, and the terminal portion of the power cable is connected to the cable head CHD. Inside the gantry 7, a current transformer CT is also arranged.

Although not shown, the operation axes for operating the bus-side disconnectors DS11 and DS12, the line-side disconnector LDS, the disconnector PDS, the test disconnector TDS, and the line-side grounding switch LES are respectively containers. It is led out to the outside and connected to a predetermined operating device (not shown). The containers 2, 5, 6, 8 and 11 have an airtight structure, and SF ₆ gas is sealed in each container at a predetermined pressure.

In the above embodiment, when conducting a DC withstanding voltage test of the power cable PC, the line side disconnecting switch LDS, the line side grounding switch LES and the disconnecting switch PDS are opened, and the test disconnecting switch TDS is set. In the closed state, connect the test cable TC to the test terminal 12 as shown in FIG. 3, and from the test DC power supply TDC, connect the cable TC, the test terminal TCHD, the test disconnector TDS, and the cable head. Apply test DC voltage to power cable PC through CHD. A test DC voltage may be applied to the power cable PC from the other end (the end opposite to the cable head CHD) of the power cable PC. In this case, the test disconnector is used. By opening the TDS, it is possible to prevent unnecessary DC voltage from being applied to each part of the gas insulated switchgear.

Further, when performing an AC withstanding voltage test on the switch circuit portion, as shown in FIG. 4, with the test disconnector TDS open, the test AC power supply TAC is connected to the test cable TC. Through the test terminal TCHD, a test AC voltage is applied to the switch circuit section including the line side disconnector LDS, the circuit breaker CB, the disconnectors DS11 and DS12, and the grounding switches ES1 and ES2.

The present invention is not limited to the configuration shown in FIGS. 1 and 2, and the busbar and the cable head are connected via the busbar-side disconnector, the circuit breaker, and the line-side disconnector. The present invention can be applied to a gas insulated switchgear having an open / close circuit. The method of housing the equipment constituting the gas insulated switchgear in the container is arbitrary.

[0032]

[Effect of device]

 As described above, according to the present invention, the test disconnector is provided between the line side disconnector and the cable head, and the test terminal to which the test cable can be connected from the outside is provided. Since the terminal was connected to the circuit between the line-side disconnector and the test disconnector, apply the test DC voltage through the test terminal with the line-side disconnector open and the test disconnector closed. This makes it possible to perform a DC withstanding voltage test on power cables. It is also possible to perform an AC withstanding voltage test on the switch circuit by applying a test AC voltage through the test terminals with the test disconnector open.

As described above, according to the present invention, the DC withstand voltage test of the power cable and the AC withstand voltage test of the switch circuit portion are performed by using the test terminal to which the test cable can be connected from the outside. Since both of these can be performed, there is an advantage that a gas treatment is not required at the time of the test, and the DC withstand voltage test and the AC withstand voltage test can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the structure of an embodiment of the present invention.

FIG. 2 is a single wire connection diagram showing an electrical configuration of an embodiment of the present invention.

FIG. 3 is a single wire connection diagram showing a state when a DC withstanding voltage test is performed on a cable in an embodiment of the present invention.

FIG. 4 is a single wire connection diagram showing a state when performing an AC withstanding voltage test of a switch circuit portion in an embodiment of the present invention.

FIG. 5 is a single wire connection diagram showing a configuration example of a conventional gas insulated switchgear.

FIG. 6 is a single wire connection diagram showing a state of performing a DC withstand voltage test of a cable in a conventional gas insulated switchgear.

[Explanation of symbols]

 BUS1, BUS1 busbar DS11, DS12 busbar side disconnector CB circuit breaker ES1, ES2 grounding switch LDS line side disconnector LES line side grounding switch TDS test disconnector CHD cable head PC power cable TCHD test terminal

Claims (1)

[Scope of utility model registration request] 1. A gas comprising a busbar conductor connected to one end of a circuit breaker via a busbar side disconnector, and the other end of the circuit breaker connected to a cable head for connecting a power cable via a lineside disconnector. In the insulated switchgear, a test disconnector is provided between the line-side disconnector and the cable head, and a test terminal is provided to which a test cable can be connected from the outside, and the test terminal is connected to the line-side disconnector. A gas-insulated switchgear characterized by being connected to a circuit between a switch and a test disconnector.