JP2953891B2 - Digital bus protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital bus protection apparatus for performing a protection operation for performing bus protection using digital data obtained by sampling a detected current from a power system and converting it into a digital amount.

[0002]

2. Description of the Related Art Conventionally, bus protection in a bus protection device has been conventionally performed by using a collective bus protection device that collectively performs a protection operation on multiple buses using digital data from each transmission line, and a transmission line connected to each bus. Divided bus protection devices have been used which divide and protect each bus of a multiple bus using digital data from the bus and digital data from the bus connecting line. These collective bus protectors and split bus protectors
, All data for each transmission line and bus connection
According to the grid connection status (operational status).
Used for each protection device's own protection operation
Data to be used and data not to be used, and
Set whether to use or not use the prepared data, and
It is configured to carry out the protective action of the period .

In a general digital bus protector, the collective bus protector and the split bus protector have almost the same digital data from the transmission line introduced for use in the protection operation. The only difference is that digital data of the bus connecting line must be separately introduced.

[0004]

As described above, in the conventional bus protection device, the protection operation using the same digital data except for the digital data from the bus connection line is performed by the collective bus protection device and the divided bus protection device as described above. because of the use, for example, it is possible to selectively set the use and non-use of the digital data from the transmission line, the setting results must match with the exception of data of busbar lines. However, since the conventional bus protection device does not sufficiently check whether the setting result matches or does not match, if a setting error occurs in any device, data necessary for the protection calculation cannot be introduced. In addition, there is a disadvantage that unnecessary data is introduced into the protection calculation, and an accurate power system protection function may not be obtained.
In addition, since digital data that can be used in common is separately introduced, unnecessary time is spent on input data processing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has high reliability and high processing efficiency by selectively using digital data from a transmission line or the like as needed. It is another object of the present invention to provide a bus protection device capable of performing a high protection operation.

[0006]

In order to achieve the above object, the present invention provides a multi-bus system in which a plurality of buses each connected to a transmission line are connected via a bus connection line. And a split bus protection device that divides and protects each bus using the amount of AC electricity from each transmission line and bus connection line. The digital bus protection device further includes a plurality of data acquisition means for individually detecting the amount of AC electricity of each transmission line and the bus connection line and outputting digital data in common with the collective bus protection device and the divided bus protection device. bulk busbar protective devices and split bus protection device, respectively, taken data set of use and non-use of the data output from the data acquisition means according to specific protection operation
Setting means for each unit of acquisition
The setting for use / non-use of the data related to
Data acquisition means as a unit, a setting confirmation means for confirming whether or not they match with the collective bus protection device and the divided bus protection device, and an abnormality process for performing an abnormality process when the setting confirmation means confirms that they do not match. Means.

Further, according to the present invention, a plurality of buses each connected to a power transmission line are connected via a bus connection line to form a double bus, and the multiple buses are collectively collected by using an amount of AC electricity from each power transmission line. A digital bus protection device comprising: a collective bus protection device for protecting; and a divided bus protection device for dividing and protecting each bus by using an AC amount from each transmission line and the bus connection line, Along with a plurality of data acquisition means for individually detecting the amount of AC electricity of each transmission line and bus connection line and outputting digital data in common with the split bus protection device, one of the collective bus protection device and the split bus protection device is A first setting unit configured to set use / non-use of data output from the data acquisition unit in accordance with the unique protection operation in units of the data acquisition unit;
The other batch busbar protective devices and split bus protection device feeding the
Data acquisition means for data on the amount of AC electricity from electric wires
Using the data acquired from the first setting means in units of
A second setting unit configured to set the use / non-use setting information as its own use / non-use setting information.

Still further, according to the present invention, a plurality of buses are connected via a bus connecting line to form a double bus, and each bus is connected to a plurality of transmission lines via disconnectors. , A collective bus protector that collectively protects multiple buses using the amount of AC electricity from each transmission line, and a divided bus protection that divides and protects each bus using the amount of AC electricity from each transmission line and bus connection line Device and the disconnection of the disconnector
Selectively use data of transmission lines connected to buses according to
Digital protection bus protection device
In accordance with the connection condition of the disconnector,
Detector that detects whether or not it is connected to the shifted bus
Stage, of the collective bus protector and the split bus protector
AC power from the transmission line
Volume data, using the output of the data acquisition unit as a unit.
To the other side and refer to the detection output of the detection
Determines whether the input AC electricity data is used or not
Setting of use / non-use of introduction data for one protection operation
And setting means for performing the setting .

[0009]

According to the first digital bus protection device described above, the collective bus protection device and the divided bus protection device (hereinafter, referred to as "the bus protection device").
Setting the use and non-use of data is also referred to) an individual protective device
The fixed information is compared, and when it is determined that they do not match, an abnormal process is performed. In this way, compared to the case where each individual protection device independently selects and sets the use / non-use of data,
A setting error of input data can be prevented, and a highly reliable bus protection device can be provided.

According to the second digital bus protection device, the setting information set by a certain individual protection device is fetched and the setting for another individual protection device is performed. Thereby, the reliability of the input data setting can be improved as a whole of the bus protection device, and the processing efficiency can be improved.

According to the third digital bus protection device, the protection calculation on the other bus is performed by using the operation data created and processed on one bus. Therefore, the data processing time can be shortened as a whole and the bus protection device can be provided with high efficiency.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a digital bus protection device according to an embodiment of the present invention. The two buses B1 and B2 to be protected are connected via a bus connecting line BT inserted through the circuit breaker CB0 to form a double bus. The transmission line L1 is connected to the bus B1 via a circuit breaker CB1, and the transmission line L2 is connected via a circuit breaker CB2. The transmission line L3 is connected to the bus bar B2 via a circuit breaker CB3.

The currents flowing through the transmission lines L1 and L2 are detected by the current transformers CT1 and CT2, respectively, and introduced into the corresponding data acquisition devices D1 and D2. The current of the bus connecting line BT is connected to the current transformers CT01, CT01 on both sides of the circuit breaker CB0, respectively.
Common data acquisition device D3 detected by CT02
Will be introduced. The current of the transmission line L3 is detected by the current transformer CT3 and introduced to the data acquisition device D4. Each of the data acquisition devices D1, D2, D3, and D4 converts the detected amount of the corresponding current transformer into an electric signal suitable for signal processing, and converts the electric signals obtained by the input converter 1 at appropriate intervals. Sampling device 2 for sampling, A / D converter 3 for converting an electric signal sampled by sampling device 2 into digital data, and A / D converter 3
The optical conversion device 4 converts the digital data obtained in the above into an optical signal. Each data acquisition device D1, D
2, D3 and D4 output optical signals are supplied to the
And the divided bus protection device 11 are commonly provided to the collective bus protection device 10 and the divided bus protection device 11 via the star coupler 5 for controlling an optical signal.

The collective bus protection device 10 and the divided bus protection device 11 are basically composed of the same components, and are respectively photoelectric conversion devices 6A and 6B, setting devices 7A and 7B,
The data control devices 8A and 8B and the protection arithmetic device 9A,
9B. The photoelectric conversion devices 6A and 6B convert an optical signal from the star coupler 5 into an electric signal and send the electric signal to the data control devices 8A and 8B. Setting device 7
A, 7B bulk busbar protection respectively, out of the data acquisition device D1, D2, D3, D4 corresponding to the protection operation on the split bus protection
A data control device 8 for setting the use or non-use of force data , and reading setting information indicating non-use for specific data from the setting devices 7A and 7B, respectively.
A and 8B forcibly set the data from the unused photoelectric conversion devices 6A and 6B to "0". Protection arithmetic unit 9A,
9B performs a protection operation (current differential principle) known as a collective bus protection device or a split bus protection device on the basis of data from the data control devices 8A and 8B, and performs a sequence of protection operation results of each bus protection device. Accordingly, a trip command, that is, a cutoff signal is issued to a predetermined circuit breaker through a system (not shown).

The operation of the bus protection device having the above configuration will be described with reference to the flowcharts of FIGS. FIG. 2 shows the processing contents of the data control devices 8A and 8B, and FIG. 3 shows the processing contents of the protection arithmetic devices 9A and 9B.

First, in step S1 of FIG. 2, the data control devices 8A and 8B are connected to the data acquisition devices D1 and D, respectively.
2, D3 and D4, the respective current data Ij introduced via the star coupler 5 and the photoelectric conversion devices 6A and 6B are read. Next, in step S2, the read data Ij is stored in a storage circuit (not shown) by each data acquisition device D1,
The data is written in a predetermined area for each of D2, D3, and D4. In step S3, use / non-use information set in advance according to the protection calculation of the collective bus protection and the division bus protection is read. Then, in step S4, the setting information of the other, that is, the divided bus protection device 11 or the collective bus protection device 10 is read via the star coupler 5, and the information set in step S5 is compared with the read setting information of the other. To the bus connecting line BT
It is checked whether they are identical to each other except for the related ones, that is, whether they are valid or not. If it is determined that the data is appropriate (match) , in step S6, "0" meaning unused data is stored in the unused area of the corresponding data acquisition devices D1, D2, D3, and D4 stored in the storage circuit. Write. That is, the unused data acquisition devices D1, D2, D
Data from 3 and D4 are forcibly set to "0" in order to be excluded from the protection operation.

In step S5, if the settings of the data acquisition devices D1, D2, D3, and D4 used do not match except for the data acquisition device D3 corresponding to the bus connection line BT, that is, If the settings of the divided bus protection device 11 do not match, it is determined that the operation is not appropriate as it is, and it is determined that it is necessary to perform an abnormality process such as device lock or an alarm, and the process proceeds to step S7, where a predetermined abnormality is detected. Execute the process.

On the other hand, the protection operation devices 9A and 9B add the data Ij read from the data control devices 8A and 8B in step S11 of FIG. In this embodiment, a protection operation based on the current differential principle is performed, and the difference current Id is a vector sum of current data, and | Id | = | ΣIj |. In the next step S12, the differential operation is determined, that is, it is determined whether or not the absolute value | Id | of the vector sum obtained in step S11 is equal to or higher than the operation level.
Outputs the determination result.

[0020] Through the above processing, advance in step S5 of FIG. 2, since performing the confirmation by reading the information in use and non-use of the preset data, the operation based on the setting information not mutually appropriate The power system can be reliably and reliably protected. Further, in the present embodiment, step S5 is performed in both, but may be performed in either one of the bus protection devices.

The set value of the operation level of the differential operation is
It is common that the collective bus protection device side and the divided bus protection device side match, and even if they are mutually confirmed, the same operation and effect as described above can be obtained.

In the above embodiment, the data acquisition devices D1 and D1 are connected through an optical data link centered on the star coupler 5.
The configuration in which data transmission is performed between D2, D3, and D4, the collective bus protection device 10, and the divided bus protection device 11 has been described as an example, but the data transmission is performed through a general LAN (local area network) or a communication network. A configuration may be adopted, and in this case, the same effect as described above can be obtained.

FIG. 4 is a block diagram showing a digital bus protection apparatus according to another embodiment of the present invention. Here, a display device 12 is provided in place of the setting device 7 in the data control device 8B of the divided bus protection device 11. A setting device 7A is connected to the data control device 8A of the collective bus protection device 10 as in the device of FIG.

The operation of the bus protection device configured as described above will be described with reference to the flowcharts of FIGS. FIG. 5 is a flowchart showing the operation of the data control device 8A on the collective bus protection device 10 side, and FIG. 6 is a flowchart showing the operation of the data control device 8B on the divided bus protection device 11 side.

The data control device 8A of the collective bus protection device 10 receives the data Ij of the corresponding data acquisition devices D1, D2, D3 and D4 as shown in step S1 of FIG.
Read. Next, the read data Ij is stored in step S
2, each data acquisition device D in a storage circuit (not shown)
Data is written in a predetermined area for each of D1, D2, D3, and D4. In step S3, use / non-use information set in advance is read from the setting device 7A. In step S6, "0" is written in the corresponding area of the unused data acquisition devices D1, D2, D3, and D4 of the storage circuit according to the setting data.

On the other hand, the data control device 8B of the divided bus protection device 11 reads the data Ij from the data acquisition devices D1, D2, D3 and D4 as shown in step S1 of FIG. Next, in step S2, the read data is stored in each data acquisition device D1, D2,
Writing is performed in an area determined for each of D3 and D4. Next, in step S7, the use / non-use information set in advance on the collective bus protection device 10 side via the star coupler (SC) 5 is read. Next, in step S8, the setting data is displayed on the display device 12. Next, in step S9, the unused data acquisition devices D1, D2 of the storage circuit are set according to the setting data.
"0" is written in the area corresponding to D3 and D4.

Then, the protection arithmetic units 9A and 9B of the collective bus protection device 10 and the divided bus protection device 11
By performing the processing shown in FIG.
A well-known protection operation for protecting the bus lines BT, B1, and the bus connection line BT is performed.

As described above, in this processing example, the setting information is read via the star coupler (SC) 5 at step S7 in the processing of FIG. 6 and is displayed on the display device 12, so that the collective bus protection device 10 and It can be confirmed that the divided bus protection devices 11 are operated with the same setting information, and as a result, more reliable operation of the power system can be realized. Also, since the setting information can be confirmed only by one bus protection device, the reliability of the device can be greatly improved with a simpler configuration.

Next, an embodiment of a system configuration different from that described above and its bus protection will be described.

In FIG. 7, two buses B1 and B2 to be protected are connected via a bus connecting line BT inserted through a circuit breaker CB0 to form a double bus. It has the same system configuration. The bus B1 is connected to the disconnector LS
11 and the circuit breaker CB1, connected to the transmission line L1, connected to the transmission line L2 via the disconnector LS21 and the circuit breaker CB2, and further connected to the disconnector LS31 and the circuit breaker C
It is connected to the transmission line L3 via B3. Similarly, the bus B2 is connected to the disconnector LS12 and the circuit breaker CB1 (the bus B1
Connected to a common transmission line L1 via a common line and a transmission line L2 via a disconnector LS22 and a circuit breaker CB2, and further connected to a transmission line L3 via a disconnector LS32 and a circuit breaker CB3. I have.

The currents flowing through transmission lines L1, L2 and L3 are detected by current transformers CT1, CT2 and CT3, respectively, and the current on bus connecting line BT is detected by circuit breaker CB0.
Are detected by current transformers CT01 and CT02, respectively. Each of the detected currents is input converters I1, I2,.
, And are sampled and held by sample and hold circuits 21, 22,..., 2N, respectively. These sample values are converted from a parallel signal to a serial signal by a multiplexer 30 and further converted to an A / D signal.
The signal is converted into a digital signal by the converter and is introduced into the protection arithmetic unit 32 for division protection. The protection operation device 32 is configured as a digital operation device mainly including a microprocessor. A state signal indicating the open / closed state of each disconnector is also input to the protection arithmetic unit 32 via an input circuit 33.

The protection arithmetic unit 32 performs a protection operation for split protection by the current of the transmission line connected to each bus, based on the current of the transmission line connected to each bus and the open / close state signal of each disconnector. Then, if it is determined that the bus has an internal accident, a signal indicating the determination result is sent to the output circuit 34. The output circuit 34 includes a protection output of a protection operation device for collective protection (not shown, but having the same block configuration) that performs a protection operation using currents of all transmission lines irrespective of the disconnection switch state signal, and the above-described division. Based on the protection output for protection and the open / close condition of each disconnector, a selective cutoff output of the bus is transmitted.

FIG. 8 is a flowchart collectively showing the processing contents of the protection arithmetic unit for division protection and collective protection. In step S21, each transmission line L1, L2,.
The current in of N is read, and in step S22, the operation amount Id is calculated using all the currents in. In step S23, the operation amount Id is compared with the operation threshold value Io, and it is determined whether or not the former is equal to or greater than the latter. If so, an output signal for collective protection is transmitted in step S24, and if not, the process skips step S24 and shifts to the next step. The processing up to step S24 is the processing for collective protection.

Next, processing for division protection will be described. Step S
At 25, the disconnector condition (disconnector opening / closing condition) jn on the bus B1 (step A) side and the disconnector condition j on the bus B2 (part B) side
Load n Otsu. Here, jn indicates a closed circuit (use) if “1”, and an open circuit (unused) if “0”. Next, in step S26, it is determined whether or not both buses are "in bridge". This determination can be made based on the presence or absence of a transmission line in which both the switching condition jn A of the disconnector connected to the bus B1 and the disconnector condition jn B of the disconnector connected to the bus B2 are “1”. it can. In the case of "during bridging", there is a process such as making the detection outputs of the current transformers CT01 and CT02 inserted in the bus connecting line BT unnecessary. However, here, there is no relation to the gist of the present invention. Omitted.

If it is determined in step S26 that the bridge is not being bridged, the operation amount Id on the bus B1 side is determined in step S27.
The instep A is calculated using the current signal of the transmission line connected to the bus B1 side according to the disconnector condition jn A. Next, step S
In step 28, similarly to step S27, the operation amount Id B on the bus B2 side is calculated using the current signal of the transmission line connected to the bus B2 side under the disconnector condition jn B. In step S29, an operation is determined for the bus B1 using the operation amount Id, and in step S30, a division protection calculation output for the bus B1 is transmitted. In step S31, the operation amount I
The operation determination is performed on the bus B2 using the device d, and the division protection calculation output on the bus B2 is transmitted in step S32.

Next, when it is determined in step S26 that the bridge is being bridged, in this case, in step S33, the operation amount Id for the bus B1 is determined using the current signals of all the transmission lines regardless of the disconnector condition. Ask. At this time, all the transmission lines are also connected to the bus B2, and the operation amount Id B for the bus B2 has the same value as the operation amount Id A. That is, in step S34, Id Party = Id Party B. Thereafter, as in the case where the bridge is not being bridged, steps S29 to S32 are executed to determine the operation of the bus B1 and the bus B2.

As described above, during the bridge, the calculation of the operation amount of all the transmission lines needs to be performed on both the bus B1 side and the bus B2 side. When the number of transmission lines (number of lines) increases, the calculation is not performed in the conventional system. Although the burden is heavy, as described above, the computational burden can be reduced by using either one of the operation amounts for both operation determinations.

In the embodiment of FIG. 8, the operation determination of both buses B1 and B2 is performed using the operation amount of one of the two buses. However, the present invention is not limited to this.
As shown in (1), any one of the motion amounts may be used to determine one of the motion amounts.

In the embodiment of FIG. 9, step S26
When it is determined in step S35 that a bridge is being performed, step S35 is performed.
Then, the bus B2 side operation amount Id O is obtained in the same manner as in step S33 of FIG.
Is used to determine the bus B2 side. It is clear that the same operation and effect can be obtained by doing so.

Further, in the embodiment of FIG. 8, the operation is determined only by the magnitude of the operation amount Id. However, this is an example, and the scalar sum or the maximum value of the current of each transmission line is calculated, and this is suppressed. The same operation and effect can be obtained even if the operation is determined as a quantity.

Thus, one of the data processing units for creating and processing the protection operation data in the bridge can be omitted, and the processing time can be reduced, and the bus having a larger number of lines (number of transmission lines) can be used. It is possible to provide a busbar protection device that can be favorably applied.

[0042]

As described above, according to the present invention, by comparing the configuration information of the use or non-use of data in each individual bus protector <br/>, bus communication
Except for those related to the fault line, when it is determined that they do not match , an
Setting errors can be prevented, and the reliability of the device can be improved.

Further , the setting of the individual bus protection device
Set to other bus protection operation means fetches the setting information
By performing constant, thereby improving the reliability of the set as a whole busbar protection device, it is possible to improve the processing efficiency.

[0044] by using an arithmetic data processed created in one of the individual bus protection device by performing protective operation of the other individual bus protection device to reduce data processing time as a whole busbar protection devices, busbar protection device with high efficiency Can be provided.

Thus, the digital bus protection device of the present invention can perform a protection operation with high reliability and high processing efficiency by selectively using digital data from a transmission line or the like as needed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital bus protection device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing processing of a data control device in the device of FIG. 1;

FIG. 3 is a flowchart showing processing of a protection operation device in the device of FIG. 1;

FIG. 4 is a block diagram of a digital bus protection device according to another embodiment of the present invention.

FIG. 5 is a flowchart showing a process of a data control device on the collective bus protection device side in the device of FIG. 4;

FIG. 6 is a flowchart showing processing of a data control device on the divided bus protection device side in the device of FIG. 4;

FIG. 7 is a block diagram of a digital bus protection device according to still another embodiment of the present invention.

FIG. 8 is a flowchart for explaining the operation of the device of FIG. 7;

FIG. 9 is a flowchart showing another embodiment of the apparatus of FIG. 7;

[Explanation of symbols]

B1, B2 Bus BT Bus connecting line CT1, CT2, CT3, CT01, CT02 Current transformer CB0, CB1, CB2, CB3 Circuit breaker L1, L2, L3 Transmission line D1, D2, D3, D4 Data acquisition device 1 Input converter 2 Sampling device 3 A / D converter 4 Optical conversion device 5 Star coupler 6A, 6B Photoelectric conversion device 7A, 7B setting device 8A, 8B Data control device 9A, 9B Protection operation device 10 Batch bus protection device 11 Split bus protection device 12 Display devices I1 to IN Input converters 21 to 2N Sample and hold circuits 30 Multiplexers 31 A / D converters 32 Protection operation devices 33 Input circuits 34 Output circuits

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuichiro Murakami 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation (56) References JP-A-1-202113 (JP, A) JP-A-4-190626 (JP, A) JP-A-1-264533 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02H 7/22

Claims (4)

(57) [Claims] A plurality of buses each connected to a transmission line are connected via a bus connection line to form a double bus, and a plurality of buses are collectively protected using the amount of AC electricity from each transmission line. In a digital bus protection device including a bus protection device and a divided bus protection device that divides and protects each bus using the amount of AC electricity from each transmission line and bus connection line,
The collective bus protection device and the divided bus protection device each include a plurality of data acquisition units that individually detect the amount of AC electricity of each transmission line and the bus connection line and output digital data, and the collective bus protection device and Each of the divided bus protection devices sets use / non-use of data output from the data acquisition unit according to a unique protection operation.
Setting means for performing data acquisition means as a unit;
Use / non-use of data on AC electricity from electric wires
A setting checking unit that checks whether or not the setting contents match with the collective bus protection device and the divided bus protection device by looking at the data acquisition unit as a unit; and if the setting checking unit does not match, A digital bus protection device, comprising: an abnormality processing means for performing an abnormality process when confirmed. 2. A plurality of buses each connected to a transmission line are connected via a bus connection line to form a double bus, and a plurality of buses are collectively protected using the amount of AC electricity from each transmission line. In a digital bus protection device including a bus protection device and a divided bus protection device that divides and protects each bus using the amount of AC electricity from each transmission line and bus connection line,
The collective bus protection device and the divided bus protection device each include a plurality of data acquisition units that individually detect the amount of AC electricity of each transmission line and the bus connection line and output digital data, and the collective bus protection device and One of the divided bus protection devices includes first setting means for setting use / non-use of data output from the data acquisition means in accordance with a unique protection operation in units of data acquisition means. and the other split busbar protection device wherein
The above data regarding the data on the amount of AC electricity from each transmission line
Import from the first setting unit in units of acquisition unit
A digital bus protection device, comprising: a second setting means for setting use / non-use setting information of self-data as self-use / non-use setting information. 3. The digital bus protection device according to claim 2, wherein the other of the collective bus protection device and the divided bus protection device uses / does not use the data fetched from the one.
A digital bus protection device comprising display means for displaying use setting information. 4. A plurality of buses are connected via a bus connection line to form a double bus, and each bus is connected to a plurality of transmission lines via a disconnector, respectively, and an amount of AC electricity from each transmission line is determined. comprising using a batch busbar protection device for protecting collectively the double bus and an AC electric quantity using split bus protection device for protecting by dividing each bus from the transmission lines and the busbar lines, the cross-sectional
Data of transmission lines connected to the bus according to the connection conditions of the road device
Digital motherboard that performs predetermined protection operation by selectively using
In the wire protection device, according to the connection state of the disconnector,
Which bus is connected to the shifted transmission line
Detecting means for detecting the
Used for protection calculation of one of the split bus protection devices
Data of the amount of AC electricity from the transmission line
The output of the acquisition means is introduced into the other unit as a unit, and
Referring to the detection output of the stage, the amount of AC electricity introduced to the other
Determines whether data is used or not, and uses the other protection operation
Setting means for setting whether to use or not use the installation data
The digital bus protection apparatus characterized by comprising.