JPH08149626A - Gas-insulated switchgear and its operating method - Google Patents

Abstract

PURPOSE: To economically discharge a DC voltage which is left on a load side when a circuit breaker is opened by connecting a high-resistance resistor between both terminals of the circuit breaker. CONSTITUTION: Since a voltage divider capacitor 16 and high-resistance resistor 18 are connected in parallel with an arc extinguishing chamber 15, namely, between both terminals 17 of a circuit breaker 11, a DC voltage left on a load side is discharged to a power source side through the resistor 18 and no DC voltage is left on the load side when the circuit breaker 11 is opened. It is desirable to set the resistance value between both terminals 17 of the circuit breaker 11 at >=1.0MΩ, because, when the resistance value of the resistor 18 decreases, the DC voltage can be discharged quickly, but the heat loss of the resistor 18 caused by an AC voltage applied across the chamber 15 increases. Therefore, the DC voltage which is left on the load side when the circuit breaker 11 is opened can be economically discharged with a small heat loss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear for discharging a DC voltage remaining after opening a circuit breaker and a method for operating the same.

[0002]

2. Description of the Related Art FIG. 7 is a circuit diagram showing a conventional gas-insulated switchgear disclosed in Japanese Utility Model Publication No. 60-162914.
Is a power supply, 2 is a disconnector, 3 is a branch bus bar, 4 is a high resistance body, 5
Is a circuit breaker, 6 is a branch busbar, 7 is a disconnector, and 8 is a busbar. Next, the operation will be described. If the circuit breaker 5 and the disconnecting switches 2 and 7 are opened while the charging current is being supplied from the power source 1 to the unloaded bus bar 8, a DC voltage remains on the branch bus bar 3. In order to prevent this, the residual DC voltage is discharged by the high resistance element 4. The capacitance of the circuit is about several thousand pF, and even a high resistance material of about several hundred MΩ can discharge the DC voltage in a short time and prevent the influence of the residual DC voltage. Since the high resistance element has a heat loss that is inversely proportional to the resistance value in the operating state, it is desirable that the value be as large as possible.

[0003]

Since the conventional gas-insulated switchgear is constructed as described above, the heat loss of the high resistance element under operating condition is several W to several hundred W per place. Therefore, there is a problem in that the heat loss increases as the number of high-resistor mounting locations increases. The present invention has been made to solve the above problems, and an object thereof is to provide a gas insulated switchgear having an economical DC voltage discharge function with little or no heat loss and an operating method thereof. And Another object is to provide a method for operating a gas insulated switchgear having a DC voltage discharge function.

[0004]

In the gas-insulated switchgear according to claim 1 of the present invention, a high resistance element is connected between both terminals of a circuit breaker. In the gas-insulated switchgear according to claim 2 of the present invention, a high resistance member of 1.0 MΩ or more is arranged in parallel with the arc extinguishing chamber between both terminals of the circuit breaker. A gas-insulated switchgear according to claim 3 of the present invention is
The bus bar is grounded via a high resistance body and a disconnector which connects and disconnects the high resistance body. In the gas-insulated switchgear according to claim 4 of the present invention, the power transmission side of the circuit breaker is grounded via a high resistance body and a disconnector for connecting and disconnecting the high resistance body.

According to a fifth aspect of the present invention, in a gas-insulated switchgear, a busbar connected to a power source through a circuit breaker is grounded through a high resistance body and a disconnecting switch connecting and disconnecting the high resistance body. After the circuit breaker is opened, the disconnector is turned on, and the circuit breaker is opened after a predetermined time. In the gas-insulated switchgear according to claim 6 of the present invention, the power transmission side of the circuit breaker is grounded via a high resistance body and a disconnector connecting and opening the high resistance body, and after the circuit breaker opens, the disconnector Is operated, and is operated so as to be opened after a predetermined time. A gas-insulated switchgear according to claim 7 of the present invention is
After the circuit breaker opens the capacitive no-load circuit, the power-side disconnector is opened, and then the load-side disconnector is opened. Further, in the gas-insulated switchgear according to claim 8 of the present invention, after the circuit breaker is opened, the disconnecting switches on both sides are opened, and then the circuit breaker is closed and opened.

[0006]

In the gas-insulated switchgear according to claim 1 or claim 2 of the present invention, since the high resistance is connected between both terminals of the circuit breaker, when the circuit breaker is cut off, the DC voltage remaining on the load side becomes high. It is discharged to the power supply side through the resistor. When the circuit breaker is closed, no voltage is applied between the high resistance terminals. In the gas-insulated switchgear according to claim 3 of the present invention, the bus bar is grounded through the high resistance body and the disconnector for connecting and disconnecting the high resistance body, so that the DC voltage is discharged from the high resistance body through the disconnector. . If the disconnector is open during normal operation, the heat loss due to the high resistance will be eliminated. In the gas-insulated switchgear according to claim 4 of the present invention, since the power transmission side of the circuit breaker is grounded via the high resistance body and the disconnector connecting and disconnecting the high resistance body, the DC voltage passes through the disconnector and has a high resistance. Discharge from the body. If the disconnector is open during normal operation, the heat loss due to the high resistance will be eliminated.

In the gas-insulated switchgear according to claim 5 of the present invention, the bus bar connected to the power source through the circuit breaker is grounded through the high resistance body and the disconnecting switch connecting and disconnecting the high resistance body, After the circuit breaker opens, turn on the disconnecting switch and operate it to open after a predetermined time.
The DC voltage remaining on the bus bar is discharged through the high resistance element when the disconnecting switch is turned on. During normal operation, the disconnector is open and there is no heat loss due to the high resistance body. Claim 6 of this invention
In the gas-insulated switchgear in, the power transmission side of the circuit breaker is grounded through a high resistance body and a disconnector that connects and disconnects this high resistance body, and after the circuit breaker is opened, the disconnector is turned on and after a predetermined time. Since the circuit breaker is operated so as to be opened, after the circuit breaker is opened, the DC voltage remaining on the power transmission side of the circuit breaker is discharged through the high resistance body when the disconnector is turned on. During normal operation, the disconnector is open and there is no heat loss due to the high resistance body.

Further, in the gas-insulated switchgear according to claim 7 of the present invention, after the circuit breaker opens the capacitive no-load circuit,
The power source side disconnector is opened and then the load side disconnector is operated so as to prevent a high DC voltage from remaining. Further, in the gas-insulated switchgear according to claim 8 of the present invention, after the circuit breaker is opened, the disconnectors on both sides are opened, and then the circuit breaker is operated so as to be closed and opened. The remaining DC voltage is discharged and averaged.

[0009]

EXAMPLE In FIG. 7, the residual DC voltage appears not only on the branch bus 3 but also on the branch bus 6 and the bus 8. The voltage depends on the opening timing of the circuit breaker 5, the disconnecting switches 2 and 7. The analysis by the inventor has revealed that the voltage is 2.5 times or more the normal voltage. Therefore, the residual DC voltage for a long time may affect the withstand voltage of the gas-insulated switchgear, and the effect is serious especially at ultra-high voltage.

Embodiment 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a circuit breaker portion in a gas insulated switchgear according to an embodiment of the present invention. In the figure, 11 is a circuit breaker of the gas insulated switchgear, and 12 is a conductive container, which is grounded. Reference numeral 13 denotes an operating device, which operates the mechanism portion 14 via the operating rod to open / close the circuit breaker 11. Reference numerals 15 and 15 denote arc extinguishing chambers, which have a two-point cut structure with a mechanism portion 14 interposed therebetween. Reference numerals 16 and 16 denote voltage dividing capacitors, which are connected in parallel with the arc extinguishing chambers 15 and 15, respectively, and are connected between both terminals 17 and 17 of the circuit breaker 11 as a whole. 1
Reference numerals 8 and 18 denote high resistance elements, which are connected in parallel with the arc extinguishing chambers 15 and 15, respectively, and are connected between both terminals 17 and 17 of the circuit breaker 11 as a whole. Reference numeral 19 is an insulating support cylinder, and 20 and 20 are connection conductors, which connect the terminals 17 and 17 to the branch buses 21 and 21. 22 and 22 are conductive containers of branch busbars, and 23 and 23 are insulating spacers that support the branch busbars. Each container 12,
The inside of 22 is filled with SF ₆ gas.

Next, the operation will be described. When the other circuit connected to the bus bar is open, the load side of the circuit breaker becomes a charging current circuit, and when the circuit breaker opens, the load side of the circuit breaker receives a DC voltage corresponding to the peak value of the AC ground voltage. To remain. In FIG. 1, when the circuit breaker 11 interrupts the charging current circuit, the DC voltage remains on the load side.
5 and 15 in parallel, that is, both terminals 1 of the circuit breaker 11
The voltage dividing capacitors 16 and 16 and the high resistance body 1 are connected between 7 and 17.
8 and 18 are connected and arranged, the DC voltage remaining on the load side is discharged to the power supply side through the high resistance elements 18 and 18, and the DC voltage does not remain on the load side. In order to quickly discharge the DC voltage, it is better to lower the resistance value of the high resistance bodies 18, 18, but when the circuit breaker 11 is open, the arc-extinguishing chamber 1
High-resistors 18,1 by AC voltage applied to 5,15
In order to reduce the heat loss of No. 8, the higher the resistance value is, the more preferable the resistance value between both terminals of the circuit breaker 11 is 1.0 MΩ or more. In the operating state of the circuit breaker 11, since the arc extinguishing chambers 15, 15 are closed, the high resistance elements 18, 18
AC voltage is not applied between the terminals of, and if the circuit breakers on both sides connected to this are opened quickly after the breaker 11 is opened, the AC voltage is applied to the high resistors 18, 18 only for a short time. , Heat loss is also reduced. Therefore, a gas-insulated switchgear with less heat loss can be realized. Although FIG. 1 shows the circuit breaker 11 having a two-point cut structure, the one-point cut structure has the same effect.

Embodiment 2 FIG. FIG. 2 is a cross-sectional view showing a busbar or a branch busbar portion in a gas-insulated switchgear according to another embodiment of the present invention. In the figure, 31 is a disconnecting switch, which has a movable portion 32, a movable contact 33, and a fixed portion 34. An operation device 35 opens and closes the disconnector 31 via an insulating operation rod 36. 37 is a conductive container of the disconnector 31 and is grounded. Insulating spacers 38 and 39 hold the disconnector 31 in the container. Reference numeral 40 is a hole provided in the insulating spacer, and 41 is a conductive container, which is grounded. Reference numeral 42 is a high resistance member, which is supported by end fittings 43 and 44 and is connected between one end of the disconnector 31 and the container 41. The high resistance body 42 is configured by accommodating a resistance block 47 crimped by a coil spring 46 in an insulating tube 45. 48 is a conductor, 49,
Reference numeral 50 denotes a conductor, which is a bus bar or a branch bus bar. Reference numeral 51 is a conductor connecting portion, and 52 is a conductive container of a bus bar or a branch bus bar. The inside of the containers 37, 41, 52 is filled with SF ₆ gas.

After opening the circuit breaker, the disconnector 31 is closed.
When a DC voltage remains on the bus of the gas insulated switchgear or the branch bus of the power transmission unit of the gas insulated switchgear, the disconnector 31
The DC voltage is discharged from the high resistance element 42 through the. The maximum capacitance of the bus bar is several thousand pF, and the maximum capacitance of the branch bus line is several μF because the capacitance of the transmission line and the cable is included.
If it is Ω or more, the DC voltage can be discharged in a short time of about several milliseconds to several seconds. Since the disconnector 31 of FIG. 2 is closed when a DC voltage remains on the bus bar or the branch bus bar, the heat loss of the high resistance body 42 during normal operation is eliminated, and therefore, the high resistance body 42 and the disconnector circuit 31 of the high resistance body 42 are eliminated. The combination is valid. The time to keep the disconnector 31 closed is
It is sufficient to make it several times the time constant τ = CR determined by the capacitance C of the circuit such as the bus bar portion and the resistance R of the high resistance body 42, and it can be controlled by a timer or the like.

FIG. 3 is a diagram showing a switching time relationship between the circuit breaker and the disconnector 31 in the second embodiment. When the circuit breaker CB is opened, the disconnecting switch 31 is subsequently closed, and the circuit breaker CB is continuously closed for several times the time constant or more and then opened. The circuit breaker CB is then closed when needed. Since the disconnector 31 connected to the high resistance body 42 can be opened during the measurement of the insulation resistance of the circuit, the soundness of the circuit can be easily checked, and therefore the disposition of the disconnector 31 is effective.

Example 3. FIG. 4 is a circuit diagram of a gas-insulated switchgear showing another embodiment of the present invention. In the figure, 6
1 is a power source, 62 is a power source side disconnector, 63 is a branch busbar, 64
Is a circuit breaker, 65 is a branch busbar, 66 is a load side disconnector, 6
7, 68 are busbars. When the other circuit connected to the bus bar 68 is open, the load side of the circuit breaker 64 becomes a charging current circuit, and when the circuit breaker 64 opens, the load side of the circuit breaker 64 corresponds to the peak value of the AC ground voltage. DC voltage remains. After this, the disconnectors 62, 66 open, but this disconnector 6
The maximum DC voltage remaining in each part varies depending on the order of 2,66.

As a first case, if the power source side disconnector 62 is first opened and then the load side disconnector 66 is opened, the load side DC voltage of the power source side disconnector 62 is about the peak value of the AC ground voltage. Fits. In the second case, when the load-side disconnector 66 is first opened and then the power-side disconnector 62 is opened, the capacitance and the capacitance of the voltage dividing capacitor that branch in parallel with the arc-extinguishing chamber of the circuit breaker 64 branch depending on the opening timing. Due to the voltage division phenomenon of the capacitance of the bus bar 65, the branch bus bar 65
High DC voltage may remain. Therefore, by forming an opening sequence of the power source side disconnecting switch 62 and the load side disconnecting switch 66 so as to always be the first case, it is possible to prevent a high DC voltage from remaining in a part of the circuit of the gas insulated switchgear. can do. 5: is a figure which shows the opening / closing time relationship of the circuit breaker 64 and disconnecting switch 62,66 in Example 3. As shown in FIG. When the circuit breaker 64 is opened, the power source side disconnector 62 is subsequently opened, and then the load side disconnector 66 is opened. Although FIG. 4 shows an example of a single bus, the same applies to the case of a double bus.

Embodiment 4 FIG. When the charging current circuit is shown in FIG. 4, there are cases in which DC voltages of different potentials remain on the branch buses 63 and 65 after the breaker 64, the power source side disconnector 62 and the load side disconnector 66 are opened. Therefore, in order to discharge and average the remaining DC voltage, and lower the potential,
It is useful to close the circuit breaker 64 after the disconnectors 62 and 66 have opened. That is, the circuit breaker 64 opens the capacitive circuit and then opens the disconnectors 62 and 66 on both sides,
After that, if an operation sequence is set up to open and close the circuit breaker 64 again, it is possible to easily discharge the residual DC voltage and lower the potential. At this time, if the circuit breaker 64 has a closing resistance, it is possible to prevent the occurrence of a high frequency surge during opening and closing, which is even more effective. FIG. 6 is a diagram showing a switching time relationship between the circuit breaker 64 and the disconnectors 62, 66 in the fourth embodiment. When the circuit breaker 64 is opened, the power source side disconnector 62 is subsequently opened, the load side disconnector 66 is subsequently opened, and the circuit breaker 64 is closed and opened. This is
Although a single bus bar has been described in FIG. 4, the same applies to a double bus bar.

[0018]

As described above, according to the gas-insulated switchgear according to claim 1 or claim 2 of the present invention, since the high resistance body is connected between both terminals of the circuit breaker, when the circuit breaker is cut off. The DC voltage remaining on the load side can be discharged to the power source side through the high resistance body. When the circuit breaker is closed, no voltage is applied between the high resistance terminals. According to the gas-insulated switchgear according to claim 3 of the present invention, the bus bar is grounded through the high resistance body and the disconnector connecting and disconnecting the high resistance body, so that the DC voltage remaining on the bus bar is increased through the disconnector. It can be discharged from the resistor. If the disconnector is open during normal operation, the heat loss due to the high resistance will be eliminated.

According to the gas-insulated switchgear according to claim 4 of the present invention, the power transmission side of the circuit breaker is grounded via the high resistance body and the disconnector for connecting and disconnecting the high resistance body. The residual DC voltage can be discharged from the high resistance through the disconnector. During normal operation,
If the disconnector is opened, the heat loss due to the high resistance will disappear. According to the gas-insulated switchgear according to claim 5 of the present invention, the busbar connected to the power source through the circuit breaker is grounded through the high resistance body and the disconnecting switch that connects and disconnects the high resistance body, and the interruption is performed. After opening the circuit breaker, turn on the disconnecting switch and operate it to open after a predetermined time, so after the circuit breaker opens,
The DC voltage remaining on the bus bar can be discharged through the high resistance element by turning on the disconnector. During normal operation, the disconnector is open and there is no heat loss due to the high resistance body.

According to the gas-insulated switchgear according to claim 6 of the present invention, the power transmission side of the circuit breaker is grounded via the high resistance body and the disconnector for connecting and disconnecting the high resistance body, and after the circuit breaker is opened. , Since the disconnecting switch is turned on and operated to open after a predetermined time, the DC voltage remaining on the power transmission side of the circuit breaker should be discharged through the high resistance body when the disconnecting switch is turned on after the circuit breaker is opened. You can During normal operation, the disconnector is open and there is no heat loss due to the high resistance body. Further, according to the gas insulated switchgear of claim 7 of the present invention, the circuit breaker operates so as to open the power source side disconnector after opening the capacitive no-load circuit, and thereafter open the load side disconnector. It is possible to prevent a high DC voltage from remaining. Further, according to the gas-insulated switchgear in claim 8 of the present invention, after the breaker is opened, the disconnectors on both sides are opened,
After that, since the circuit breaker is operated so as to be turned on and off, the DC voltage remaining between the two disconnectors can be discharged and averaged.

[Brief description of drawings]

FIG. 1 is a sectional view showing a circuit breaker portion in a gas insulated switchgear according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a busbar or a branch busbar portion in a gas-insulated switchgear according to another embodiment of the present invention.

FIG. 3 is a diagram showing a switching time relationship between a circuit breaker and a disconnecting switch according to a second embodiment.

FIG. 4 is a circuit diagram of a gas insulated switchgear showing another embodiment of the present invention.

FIG. 5 is a diagram showing a switching time relationship between a circuit breaker and a disconnecting switch according to a third embodiment.

FIG. 6 is a diagram showing a switching time relationship between a circuit breaker and a disconnector according to a fourth embodiment.

FIG. 7 is a circuit diagram showing a conventional gas-insulated switchgear.

[Explanation of symbols]

11 circuit breaker 12 container 1
5 Arc-extinguishing chamber 16 Voltage dividing capacitor 17 Terminal 1
8 High Resistor 21 Branch Bus 31 Disconnector 3
7 Container 41 Container 42 High Resistor 4
9 conductor 50 bus 61 power 6
2 Disconnector 64 Circuit breaker 66 Disconnector 6
7 bus

Claims (8)

[Claims] 1. A gas-insulated switchgear having a circuit breaker, a disconnector, and a busbar, in which a high-resistance element is connected between both terminals of the circuit breaker. 2. A circuit breaker, a circuit breaker, and a bus bar, wherein 1.0M is provided between both terminals of the circuit breaker in parallel with the arc extinguishing chamber.
A gas-insulated switchgear with a high resistance of Ω or more connected. 3. A gas-insulated switchgear having a circuit breaker, a disconnector, and a busbar, wherein the busbar is grounded via a high-resistance body and a disconnector for connecting and disconnecting the high-resistance body. 4. A gas-insulated switchgear having a circuit breaker, a disconnector, and a busbar, in which the power transmission side of the circuit breaker is grounded via a high resistance body and a disconnector for connecting and disconnecting the high resistance body. 5. A bus bar connected to a power source through a circuit breaker is grounded through a high resistance body and a disconnector for connecting and disconnecting the high resistance body, and after the circuit breaker is opened, the disconnector is turned on. Then, a method of operating the gas insulated switchgear that opens after a predetermined time. 6. The power transmission side of the circuit breaker is grounded via a high resistance body and a disconnector connecting and opening the high resistance body, and after the circuit breaker is opened, the disconnector is turned on and opened after a predetermined time. How to operate gas insulated switchgear. 7. The power source side disconnecting switch is connected to the power source side of the circuit breaker, and the load side disconnecting switch is connected to the load side, respectively, and the power source side disconnecting circuit is provided after the circuit breaker opens the capacitive no-load circuit. A method of operating a gas-insulated switchgear in which a switch is opened and then the load side disconnector is opened. 8. A gas-insulated switch in which a circuit breaker is connected to both sides of the circuit breaker, the circuit breakers on both sides are opened after the circuit breaker is opened, and then the circuit breaker is closed and opened. How to operate the device.