JPH035129B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a busbar protection relay device in which protection relay devices are distributed in the vicinity of a breaker.

[Prior art]

FIG. 1 shows an example of a single-line connection diagram of an ultra-high voltage substation having a busbar configuration with double busbars and four bus ties.

According to this configuration, the high voltage buses B ₁₁ , B ₁₂ , B ₂₁ ,
Similar to B ₂₂ , the low voltage buses B ₃₁ , B ₃₂ , B ₄₁ , B ₄₂ are connected to adjacent bus bars and busbar connection sheath breakers CB ₁ to _{CB 4} , respectively.
Similarly, connections can be made using the busbar connection shield disconnectors CB ₅ to _{CB 8} , and among these busbar connection shield disconnectors CB ₁ , CB ₂ , CB ₅ , and CB ₆ are normally operated open. Ru. Also, between bus bars that are connected and operated (B ₁₁
and B ₂₁ , B ₁₂ and B ₂₂ , B ₃₁ and B ₄₁ , and B ₃₂ and B ₄₂ ), at least two disconnectors D are installed in series, and a transmission line disconnector CB ₁₁ is connected between the disconnectors D. ~ _CB16 , _CB31 ~
Power transmission lines L ₁₁ to L ₁₆ and L ₃₁ to _{L 36} are connected via CB ₃₆ . In addition, there are no shears or disconnectors between the high-voltage busbar and the low-voltage busbar.
Transformers _T1 to _T4 are installed via _CB21 to _CB28 .

In this figure, CT and PD are current transformers and voltage transformers for current and voltage detection, respectively. The detected current and voltage signals are provided to the protective relay device, which is given an open command to the breaker CB. Figure 2 shows the current and voltage signal lines that are input to the protective relay device related to a part of the bus B ₁₁ and the transformer T ₁ of the transmission line L ₁₁ , and shows the current and voltage signal lines that are input to the protective relay device. (Separate signal lines are provided for each transmission line protection relay device (A system, B system, backup), busbar protection relay device, and transformer protection relay device (main protection, backup protection) to improve reliability. Because of this, a large number of signal lines are required.These signal lines are led to unit rooms UR ₁ to UR ₄ where protective relay devices are installed. However, the cable group that guides the trip command from this protective relay device to the corresponding disconnector CB and the opening/closing of the disconnector D that indicates which of the two busbars each power transmission line L is connected to A group of cables to indicate the status and operation information of the device are sent to the unit room UR.
A large number of cables will be installed to lead to monitoring panels, etc.

In this conventional method of storing protective relay devices in substations in the unit room UR, the amount of wiring between the unit room and each detector or disconnector is enormous, so No. 43115 proposes installing protective relay devices in a distributed manner near individual circuit breakers.

[Problem to be solved by the invention]

In the above-mentioned known example, the protective relay devices are arranged in a distributed manner for each line disconnector, but there is no suggestion as to how to configure the busbar protective relay device among the plurality of protective relay devices.

In view of the above, it is an object of the present invention to provide a busbar protection relay device suitable for a system in which the protection relay device is installed near a breaker.

[Means to solve the problem]

The busbar protection relay device of the present invention includes a plurality of busbars connected via a busbar communication shield and disconnector, a switch provided in series between the plurality of busbars, and a conductor and disconnector between the switches. It is applied to a substation busbar consisting of multiple lines connected through It consists of a protective relay device that issues a trip command, and a signal transmission path installed between multiple protective relay devices installed at each line edge or disconnection. signal receiving means for receiving the transmission signal, sampling means for sampling and inputting the line current by all protective relay devices in synchronization upon receiving the synchronization signal included in the transmission signal, and sampling means for inputting the current value input by the sampling means. The signal sending means sends the signal to the signal transmission line after a predetermined period of time from the synchronization signal reception time, and the current value inputted by the own sampling means and the current value inputted through the signal receiving means are taken into consideration in their polarity. It is configured to include an adding means for adding, and a tripping means for giving a tripping command to its own line switch or disconnector according to the output of the adding means.

[Effect]

According to the present invention, the current is sampled at the same time in each protective relay device provided for each circuit breaker, and this is superimposed on the signal transmission path.
All protective relay devices can input the total current necessary to provide busbar protection. Therefore, each protective relay device can protect the busbar by executing a differential calculation based on all the currents input thereto and giving a tripping command to its corresponding shield disconnector.

〔Example〕

Fig. 3 shows a schematic configuration of the present invention, and since the busbar protection is often operated with the busbar connection and disconnectors CB ₁ and CB ₂ open, as described above, , with bus lines B ₁₁ and B ₁₂ as one protection unit, find the vector sum of all the currents flowing into and out of the protection unit line, and if this is not zero,
All transmission line disconnectors and transformer disconnectors that are connected to this protection unit bus and supply or are supplied with current are operated as if they were opened. Therefore, when the busbar communication shield breakers CB ₁ and CB ₂ are closed, the area including the busbars B ₁₂ and B ₂₂ is protected.

In the present invention, each side disconnector CB ₁₁ to _{CB 14} ,
A protective relay device _21-28 , 201, 202 is installed for each of CB 21, CB ₂₂ , CB ₁ , CB ₂ , CB ₃ , and each protective relay device 21-28, 201, 202 is controlled by its own The current flowing through the disconnector is converted to a current transformer CT.
The voltage of the line connected to the transformer PD is detected by the PD
Enter via. These protective relays 21-2
8, 201, and 202 are connected to each other by a signal transmission path _FB1 so as to enable signal transmission. Although the illustrated signal transmission path is a loop transmission path, this is not limited to a loop type. In the figure, for example, an optical fiber transmission line can be used as the signal transmission line, and in this case, 211-1, 211-2
21-1, 231-1, 241-1, 202-
1,204-1,251-1,261-1,27
1-1, 281-1 is an optical splitter for taking the signal into the protective relay, 212-1, 222-1, 2
32-1, 242-1, 203-1, 205-
1,252-1,262-1,272-1,28
2-1 indicates an optical adder for sending a signal to the signal transmission path _FB1 .

Figure 4 shows the protective relay device (21 and 2 in this example).
8 (only 8 is representatively shown) is a diagram showing a specific configuration of the main building device 1 for transmitting signals to each protective relay device 21, 28. The transmitter 11 of the transmission device installed in the main building 1 transmits a signal frame of the transmission signal format shown in FIG. (consisting of a word slot) to the optical fiber transmission line FB1. The transmission signal format sent from the transmitter 11 in this way passes through the optical fiber transmission line FB1 and is transmitted to each protective relay device 21 to 28. The device includes optical splitters 211-1 and 281.
Since the receivers 213 and 28 are equipped with
3, this signal format is derived. Taking the protective relay device as an example in the following explanation, this receiving section 213 includes, for example, a PIN type photodiode D1 and a level converter LC1 that performs level shaping of the electrical signal in order to restore the guided optical signal to an electrical signal. and synchronization signal word detection unit SYC and serial/parallel conversion circuit
Consists of SP.

The relay unit 215 in the protective relay device 21 has an input line for the information of the serial-to-parallel conversion circuit SP, and
Signal line 2 that receives current information from the relevant current transformer CT
16. A signal line 217 is provided to receive voltage information from the voltage transformer PD as necessary, and based on this information, when an accident has occurred on the relevant bus bar is detected by the method described later, the relevant line or disconnector is activated. A trip command is issued to the output via signal line 218.

The relay unit 215 sends a synchronization signal that receives the current and voltage at its own end to the transmitter 214.
Synchronized sampling at each end based on SYC
AD conversion information and related disconnector opening/closing information (D information) are given via a signal line 219. This transmitting section 214 is notified to this effect via the signal line SYD when the synchronizing signal word detecting section SYC of the receiving section 213 detects a synchronizing signal word of the transmission signal format sent from the transmitting section 11 of the parent device 1. Therefore, using this time as a time base, the parallel-to-serial converter PS installed inside the device inserts it into the corresponding bit position of the word slot given to it in the transmission signal frame (Figure 5) and sends it out. (The embodiment shown in FIG. 5 shows an example in which there are a maximum of nine protective relay devices. For example, the system information of the bus protection relay device 21 and the related disconnector information LS, etc. are based on the station number. S#1
As shown in the figure, each phase current value i _a , i _b , _ic , each phase voltage value v _a , v _b , v _c and switch information LS word are inserted as appropriate in the corresponding word positions W#1 to W#7. and then W
For example, #8 is a redundant bit for error control determined by the information content of W#1 to W#7.
(insert CRC verification word).

Note that the protective relay device 21 superimposes its own detection information on the station number S#1, but in the same way, the protective relay device 22 is assigned to S#2, and the protective relay device 22 is assigned to S#3. Therefore, current information from all parts related to bus bar protection will be transmitted as signals. More specifically, the output of the parallel-to-serial converter PS of the transmitter 214 is transmitted to the transmitter level shaping circuit LC2.
For example, a photodiode D2 for electro-optical conversion
After being converted into an optical signal by the light guide
It passes through FB212 and is sent to optical fiber transmission line FB1 via optical adder 212-1.

Finally, to explain the processing within the protective relay unit 215, as described above, each protective relay device achieves synchronous sampling by sampling the current at each end in synchronization with the synchronous signal SYC from the main building. This current value is superimposed on a predetermined position of a signal frame starting from the synchronization signal SYC and sent to the signal transmission path FB1. Therefore, the reception unit 13 of the main building and each protective relay device can obtain the currents at all current measurement points as digital values sampled at the same time. From this, in each protective relay device, if this digital value is added considering the positive and negative polarities, the added value will not become zero only when an accident occurs on the bus to be protected. Accidents can be detected. Then, by giving an open command to the disconnector CB assigned to each protective relay device, it is possible to open all relays and disconnectors connected to the bus as a whole, so-called bus protection. can be realized.

In addition, in the above explanation, word slot W#4
~The voltage signal of W#6 and the opening/closing information of W#7 and the disconnector have no direct relationship in realizing busbar protection based on the differential principle, but they are used to display the status of each part on the monitoring panel in the main building. It is essential as information.

Furthermore, in the above explanation, it is assumed that a protective electrical device is installed for every switch and disconnector that connects to the busbar to be protected, but from the perspective of providing differential protection for the busbar, all It is not necessary to collect the current flowing through the disconnector on the signal transmission line, but it is sufficient to collect the current on the line connected to the bus bar. In other words, in the example shown in Fig. 3, it is sufficient to have the currents of CT ₁₁ to CT ₁₄ , CT ₅₁ , and CT ₆₁ , and for example, since CB ₁ and CB ₂ are always open and operated, CT ₂ and CT ₄ Since the detection current of CT ₅ ,
The detection current of CT ₆ does not need to be used in differential calculations because it does not flow into or out of the protected bus.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a busbar protection relay device suitable for a substation in which a protection relay device is disposed for each line breaker.

[Brief explanation of drawings]

Figure 1 is a schematic single-line diagram of the entire double bus substation, Figure 2 is a diagram showing input and output signals to one unit room of the substation, and Figure 3 is the signal transmission equipment and protective relay equipment. FIG. 4 is a diagram showing the details of the protection relay device, and FIG. 5 is a diagram showing the frame structure of signal transmission. 21-28...protective relay device, CB...wire breaker, CT...current transformer, PD...voltage transformer, L...
…power line.

Claims (1)

[Scope of Claims] 1. A plurality of busbars connected via a busbar communication shield and disconnector, a disconnector provided in series between the plurality of busbars, and a mustard and disconnector connected between the disconnectors. In a bus protection relay device for protecting a substation bus consisting of a plurality of connected lines, the relay is installed at each line break or disconnection, detects and inputs the current flowing through the line, and It consists of a protective relay device that gives a trip command to the line breakers, and a signal transmission line installed between multiple protective relay devices installed for each line breaker, and provides the above protection. The relay device includes a signal receiving means for receiving a transmission signal on a signal transmission path, a sampling means for receiving a synchronization signal included in the transmission signal, and sampling and inputting the line current by all protective relay devices in synchronization, and a sampling means. A signal sending means sends out the current value inputted by the user to the signal transmission path after a predetermined period of time from the time of receiving the synchronization signal, and the current value inputted by the own sampling means and the current value inputted through the signal receiving means are inputted. A bus protection relay comprising an addition means for adding current values in consideration of their polarities, and a tripping means for giving a tripping command to its own line breakers or breakers in accordance with the output of the addition means. Device.