KR20100138211A - Ac power supply for gas isulated switchgear - Google Patents

Abstract

PURPOSE: A power supply device is provided to minimize the generation of damage due to the delay of power supply by supplying AC power after converting DC power inside a power substation when power is disconnected in the substation. CONSTITUTION: An inverter(31) outputs power after converting DC power into AC power. A transformer(32) outputs power after converting the AC power outputted from the inverter. A current transformer(CT1) detects a current supplied from the AC power source part in a substation. A static switch(33) supplies the AC power, which is supplied from the transformer, to a device. A controller(34) controls the location of the static switch to be switched when power is disconnected.

Description

AC POWER SUPPLY FOR GAS ISULATED SWITCHGEAR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear, and more particularly, to a power supply of a gas insulated switchgear capable of supplying AC power when a power outage occurs in a substation.

Gas insulated switchgear that can be used in substation with handling voltage of hundreds of kilovolts, protects power system by blocking the line in abnormal state of power circuit such as ground and short circuit as well as opening and closing of circuit in normal state of transmission line and substation line. As a power device, a power device that opens and closes a circuit in an insulating gas enclosed in order to open and close an ultra high voltage electric power.

The gas insulated switch is composed of a switchgear mechanism for opening and closing the ultra-high voltage electric power and a device operating panel having an electronic circuit for monitoring and operating the switchgear. The electric device included in the opening and closing mechanism includes a hydraulic motor (which is a three-phase AC motor) and a heater circuit that provides power for opening and closing operation, and the electric device included in the device control panel includes a device operation circuit and an alarm. There is a circuit.

In the power supply device of a gas insulated switchgear according to the prior art, a hydraulic motor and a heater, which are supplied with a DC power required for the apparatus control panel from a DC power source such as a back-up battery in a substation in a normal state and require AC power. The circuit receives AC power from an on-site AC power source supplied by substituting (stepping down) the AC power received.

However, when a power outage occurs in a substation, DC power can be supplied from the backup battery, but AC power required to drive the hydraulic motor and heater circuit driving the switch mechanism is not supplied. There was a problem that there is a possibility of damage caused by the delay of power supply and accident of power system.

Accordingly, the present invention is to solve the problems of the prior art, the object of the present invention is to provide a quick repair work for the power failure by converting the DC power in the house even when the power outage in the substation occurs, the damage caused by the delay of power supply It is to provide a power supply of a gas insulated switchgear that can minimize the occurrence and eliminate the possibility of an accident of the power system.

The above object of the present invention is a gas insulated switchgear installed in a substation and electrically connected to an on-site alternating current power source and an on-site direct current power source of the substation, wherein the power supply device of the gas insulated switchgear supplies power to an electric device inside the gas insulated switchgear. To

Connected to the on-site AC power supply side of the substation and the on-site DC power supply side of the substation,

Normally, AC power supplied from the on-site AC power supply is supplied to an AC power operation device in the gas insulated switchgear,

When a power failure occurs in the substation, the power failure is detected based on the amount of current supplied from the internal AC power supply.

It can be achieved by providing a power supply of the gas insulated switchgear according to the present invention, including an AC power supply for converting the DC power supplied from the on-site DC power supply to an AC power supply to the AC power operation device.

The power supply device of the gas insulated switchgear according to the present invention has a means for automatically detecting the occurrence of a power outage in the event of a power outage and converting the DC power in the substation into an AC power supply, thereby facilitating quick maintenance work for power failure and supplying power. Minimize damage caused by delay and eliminate the possibility of power system accident.

The power supply device of the gas insulated switchgear according to the present invention includes a circuit breaker connected to the DC power supply side, a circuit breaker connected to the AC power supply side, and a circuit breaker connected to the final output side of the power supply device. In case of abnormal output power, circuit can be cut off to protect AC load such as motor and heater which are powered by power supply itself and power supply device from accident current.

The power supply of the gas insulated switch according to the present invention includes a display unit for displaying the current, voltage and frequency of the power from the AC power terminal and the current, voltage and frequency of the output power of the rear end of the static switch, AC The effect of monitoring the current, voltage and frequency of power on the power supply side and the output side of the power supply can be obtained.

The object of the present invention and the constitution and effects of the present invention to achieve the same will be more clearly understood by the following detailed description of the preferred embodiment of the present invention with reference to the accompanying drawings.

First, a diagram showing a configuration of an electrical functional unit in a gas insulated switchgear including a power supply device according to the present invention and a connection diagram of an AC power source and a DC power source in a substation outside the gas insulated switchgear and a power circuit in a substation. It demonstrates with reference to 1.

As shown, the gas insulated switchgear including the power supply device according to the present invention and the power supply circuit in the substation are largely divided into in-house DC power supply (DC) and in-house AC power supply (AC) in the substation (hereinafter abbreviated as in-house) and It is composed of a gas insulated switch (100). The on-site DC power supply DC and the on-site AC power supply AC are respectively connected to the DC power supply terminal 10 and the AC power supply terminal 20 in the gas insulated switch 100 to supply DC power and AC power. The DC power terminal 10 and the AC power terminal 20 are hydraulic motors, which are AC power operating devices in the device operation and alarm circuit 40 and the gas insulated switch 100 which are DC power operated devices in the gas insulated switch 100, respectively. And a heater circuit 50 to supply DC power and AC power from the in-house DC power source DC and in-house AC power source AC.

Figure 2 is a detailed functional block diagram showing a detailed configuration of the power supply of the gas insulated switchgear according to the present invention.

The power supply device of the gas insulated switchgear according to the present invention is an AC power supply device 30, the AC power supply device 30 is on the in-site AC power side of the substation and the in-site DC power side of the substation as shown in FIG. Connected. In other words, the AC power supply device 30 is connected to the in-house DC power supply DC and the in-house AC power supply AC through the DC power supply terminal 10 and the AC power supply terminal 20.

 The AC power supply device 30 normally supplies AC power supplied from the in-house AC power supply to an AC power operation device, that is, the hydraulic motor and the heater circuit 50 of FIG. 1, and when the power failure occurs inside the substation, the in-house AC power supply side. The power failure is detected based on the amount of current supplied from the power supply, and the DC power supplied from the in-house DC power supply side is converted into an AC power and provided to the AC power operation device, that is, the hydraulic motor and the heater circuit 50.

On the other hand, the detailed configuration and operation of the AC power supply device that is the power supply of the gas insulated switch according to the present invention will be described with reference to FIG.

The AC power supply device 30 includes an inverter 31, a transformer 32, a first current transformer CT1, a static switch 33, and a controller 34.

Here, the inverter 31 is connected to the on-site DC power supply side, and converts DC power into AC power and outputs it. That is, the inverter 31 is connected to the in-house DC power supply DC through the DC power supply terminal 10 in FIG. 1, and converts and outputs the DC power from the in-house DC power supply DC into AC power.

The transformer 32 is connected to the inverter 31, and converts and outputs the AC power output from the inverter 31, wherein the voltage conversion is based on the rated voltage of the hydraulic motor using the AC power output. It can be a conversion to step up or step down the output voltage of) and the winding ratio of the primary side and the secondary side of the transformer 32 can be determined according to the step-up or step-down.

The first current transformer CT1 is connected to the internal AC power supply side and detects the amount of current supplied from the internal AC power supply side. That is, the first current transformer CT1 is connected to the in-house AC power source AC through the AC power supply terminal 20 in FIG. 1 to detect the amount of current supplied from the in-house AC power source AC.

The static switch 33 has a position electrically connected to the first current transformer CT1 and the on-site AC power supply side at normal times, and a position electrically connected to the transformer 32 at the occurrence of a power failure in the substation. AC power supplied from the power supply is supplied, and AC power supplied from the transformer 32 is supplied to the AC power supply operation device in the event of a power failure. In other words, the static switch 33 has a position which is normally electrically connected to the in-house AC power source AC through the first current transformer CT1 and the in-house AC power supply side, that is, the AC power supply terminal 20. 33 has a position that is electrically connected to the transformer 32 in the event of an on-site power failure. The position switching of the static switch 33 is made by the control of the control part 34. When the static switch 33 normally has a position electrically connected to the first current transformer CT1 and the on-site AC power supply side, the on-site AC power AC is supplied through the static switch 33 as a result, and the static switch When the 33 has a position electrically connected to the transformer 32 in the event of a power outage, the on-site DC power source DC is converted into alternating current by the inverter 31 and the power transformed by the transformer 32 is static. It can be supplied via the switch 33.

The control unit 34 is connected to the first current transformer CT1 and the static switch 33 to detect a power failure based on the amount of current from the first current transformer CT1, and detects the position of the static switch 33 when the power failure is detected. Control to switch to a position electrically connected to the transformer. The control unit 34 compares the amount of current in the on-site AC power source AC represented by the current amount detection signal from the first current transformer CT1 with a predetermined reference value, for example, the in-house AC power source (1) detected by the first current transformer CT1 from the reference value. It may be composed of a circuit portion having a microprocessor for determining the occurrence of power failure when the current amount of AC) is small and emitting a switch control signal for controlling the position switching of the static switch 33. The control unit 34 further includes a current A, a voltage V and a frequency F for the electric power from the internal AC power supply side, a current A for the output power after the static switch 33, And a display unit for displaying the voltage V and the frequency F, the current DC A and the voltage DC V from the in-house DC power supply. The display unit may be configured by, for example, a liquid crystal display. The current A with respect to the power from the on-site AC power supply side can be detected by the first current transformer CT1, and the voltage V with respect to the power from the on-site AC power supply side is not shown in the corresponding line. The frequency (F) detection of the power from the on-site AC power supply side by means of a voltage transformer of can be detected using a frequency detection circuit such as a timer counter. The current A for the output power after the static switch 33 can be detected by the second current transformer CT2, and the voltage V and the frequency F for the output power after the static switch 33 are respectively. It can be detected by using a frequency detection circuit such as a timer counter (not shown) by a voltage transformer not shown in the line. The current DC A and the voltage DC V from the on-site DC power supply side can also be detected by a current transformer and a voltage transformer, not shown, installed on a line behind the second circuit breaker CB2.

Meanwhile, as shown in FIG. 2, the AC power supply 30 may further include a first circuit breaker CB1, a second circuit breaker CB2, and a third circuit breaker CB3. Can be.

 The first circuit breaker CB1 is connected to the in-house AC power supply and is built in the AC power supply 30 so that when an abnormality (overcurrent, short-circuit current, etc.) occurs in the in-house AC power supply, The power circuit supplied into the AC power supply 30 is cut off.

The second circuit breaker CB2 is connected to the on-site DC power supply side and built in the AC power supply device 30, and when an abnormality occurs in the on-site DC power supply, the AC power supply device 30 is supplied from the on-site DC power supply side. Shut off the power circuit to be fed into.

The third circuit breaker CB3 is connected to the rear end of the static switch 33 and built in the AC power supply 30, and when an abnormality occurs in the final output AC power of the AC power supply 30, the AC power source The power circuit supplied from the supply device 30 is cut off.

Referring to the operation of the power supply of the gas insulated switchgear of the present invention configured as described above is as follows.

The operation of the power supply device of the gas insulated switchgear of the present invention will be described by dividing the AC power supply operation in normal operation and the AC power supply operation in the event of a power failure in a substation.

First, in the normal state, that is, in a state where power of the on-site AC power source AC is normally supplied, the on-site AC power side current amount detected by the first current transformer CT1 is compared by the control unit 34 with the reference current value. As a result of the comparison, since the amount of current in the on-site AC power supply detected by the first current transformer CT1 is larger than the reference current value (the minimum current value for determining the power failure), the control unit 34 determines that the steady state and the static switch 33 It does not emit a signal that controls to switch positions. Therefore, since the static switch 33 is located at a position electrically connected to the first current transformer CT1 and the on-site AC power supply side, the normal AC power from the on-site AC power source AC is controlled from the static switch 33. It is output as the final output of the power supply of the gas insulated switchgear through the three circuit breakers CB3. The corresponding AC power that is finally output is supplied to the hydraulic motor and the heater circuit 50, which are the AC power operating device of FIG.

On the other hand, when a power outage occurs in a substation, the power of the on-site AC power source AC is stopped and the DC power from the on-site DC power source DC, which is a reserve power source, is supplied to the inverter 31 through the second circuit breaker CB2. . The inverter 31 converts and outputs DC power from in-house DC power supply DC into AC power, and the AC power is transformed by the transformer 32 and applied to the static switch 33. At this time, the on-site AC power side current amount detected by the first current transformer CT1 is compared with the reference current value by the control unit 34. As a result of the comparison, the on-site AC power side current amount detected by the first current transformer CT1 is a reference current value. Since it is less than or equal to (the minimum current value for determining the power failure), the control section 34 determines the state of occurrence of power failure and issues a switch control signal to switch the position of the static switch 33. Therefore, since the static switch 33 is located at a position electrically connected to the transformer 32 side, the AC power during on-site power failure from the transformer 32 is passed through the static switch 33 and the third circuit breaker CB3. It is output as the final output of the power supply of the gas insulated switchgear. The corresponding AC power that is finally output is supplied to the hydraulic motor and the heater circuit 50, which are the AC power operating device of FIG.

As described above, since the power supply device of the gas insulated switchgear according to the present invention has a means for automatically detecting the occurrence of a power outage and converting the DC power in the substation into an AC power supply, a quick repair work for the power outage is performed. It has the advantage of making it possible to minimize damage caused by delay of power supply and to eliminate the possibility of power system accident.

1 is a configuration diagram of a gas insulated switchgear and a substation power supply circuit showing a configuration of an electrical functional unit in a gas insulated switchgear including a power supply device according to the present invention and a connection configuration of an AC power source and a DC power source in a substation outside the gas insulated switchgear. ,

Figure 2 is a detailed functional block diagram showing a detailed configuration of the power supply of the gas insulated switchgear according to the present invention.

* Explanation of symbols on the main parts of the drawings

10: DC power terminal 20: AC power terminal

30: AC power supply 31: Inverter

32: transformer 33: static switch

40: device operation and alarm circuit 50: hydraulic motor and heater circuit

100: gas insulated switchgear AC: house AC power

DC: In-house DC power supply CB1: First circuit breaker

CB2: Second Circuit Breaker CB3: Third Circuit Breaker

Claims (4)

In the gas insulated switchgear installed in the substation and electrically connected to the on-site AC power source and the in-site DC power source of the substation, the power supply device of the gas insulated switchgear which supplies power to the electric device inside the gas insulated switchgear, Connected to the on-site AC power supply side of the substation and the on-site DC power supply side of the substation, Supplying AC power supplied from the on-site AC power supply to an AC power operation device in the gas insulated switchgear, When a power failure occurs, the power failure is detected based on the amount of current supplied from the in-site AC power supply, And an AC power supply for converting the DC power supplied from the on-site DC power supply into an AC power and providing the AC power operation device to the AC power supply device. The method of claim 1, The AC power supply, An inverter connected to the internal DC power supply and converting the DC power into AC power; A transformer connected to the inverter for converting and outputting an AC power output from the inverter; A current transformer connected to the on-site AC power supply side and detecting an amount of current supplied from the on-site AC power supply side; And a position electrically connected to the current transformer and the on-site AC power supply side, and a position to be electrically connected to the transformer when a power failure occurs, and supplying AC power supplied from the on-site AC power supply device to the AC power supply operation device, A static switch for supplying AC power supplied from the transformer to the AC power operation device in the event of a power failure; And A control unit connected to the current transformer and the static switch to detect a power failure based on the amount of current from the current transformer, and control to switch the position of the static switch when the power failure is detected; Power supply of the gas insulated switchgear comprising a. The method of claim 2, A power circuit connected to the on-site AC power supply and embedded in the power supply of the gas insulated switchgear and supplied to the power supply of the gas insulated switchgear from the on-site AC power supply when an abnormality occurs in the on-site AC power supply. A first circuit breaker for blocking; A power circuit connected to the on-site DC power supply and embedded in the power supply of the gas insulated switchgear, and supplied to the power supply of the gas insulated switchgear from the on-site DC power supply when an abnormality occurs in the on-site DC power supply. A second circuit breaker for blocking; And It is connected to the rear end of the static switch and built in the power supply of the gas insulated switchgear, and when an abnormality occurs in the final output AC power of the power supply of the gas insulated switchgear, it is supplied from the power supply of the gas insulated switchgear. A third circuit breaker for shutting off the power circuit; Power supply of the gas insulated switchgear further comprising a. The method of claim 2, The control unit, And a display unit for displaying current, voltage and frequency with respect to power from the on-site AC power supply side, current, voltage and frequency with respect to output power at the rear end of the static switch, and current and voltage from the on-site DC power supply side. Power supply of the gas insulated switchgear characterized in that.

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