JPH03265419A - Automatic inspection circuit for current differential relay device - Google Patents

Abstract

PURPOSE:To prevent the title circuit from making a wrong inspection by transmitting the operation of a fault detecting relay on the opposite end as part of control data and stopping automatic inspection of its own end by means of the data received at its own end. CONSTITUTION:When an external fault occurs while an inspection command 20 is outputted, fault detecting relays 2A and 2B at its own end and the opposite end operate. Therefore, an AND circuit 51A is established and an inspection stop command is given to the AND circuit 51A through an OR circuit 6A. At the same time, operation of the relay 2B at the opposite end is received at its own end and the inspection stop command is given to an inspection circuit 3A so as to stop the automatic inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an automatic inspection circuit for a current differential relay device for protecting an electric power system.

(Prior art) A protective relay device used to protect an electric power system usually consists of an accident detection circuit that detects an accident in the system and an internal accident detection circuit that detects that the accident in the system is inside a protected area. Ru. As a protection method for power transmission lines, there is a current differential protection method that mutually transmits the current value at each end of the power line, but this method is selective in terms of faults.

It is advantageous in terms of accident removal time, and is currently used in most of the main power systems.

In recent years, current differential protection methods have been developed by converting the current value at each end of a power transmission line into digital data and transmitting this data together with control data indicating the status of control equipment at each end. A digital current differential relay device is used, and the internal fault detection circuit is often a current differential relay, and the fault detection circuit is often an undervoltage relay.

FIG. 7 shows a block diagram of a conventional current differential relay device.

In Fig. 7, internal fault detection relay 1^ and fault detection relay 2A are connected to NO circuit 5A, and inspection command 1, which is the output of inspection circuit 3A, is also ANDed through NOT circuit 4A.
It is connected to circuit HI5A and gives a breaker disconnection command when AND circuit 5^ is established. Furthermore, inspection command 2 and inspection command 3, which are the outputs of the inspection circuit 3^, are configured to give inspection inputs to the electric appliances 1^ and 2A, respectively. In addition, the inspection cancellation command is output from an AND circuit 51A that connects the inspection command 20 that is the output of the inspection circuit 3^ and the output of the relay 2^, and the inspection command 30 that is also the output of the inspection circuit 3^.
The output of the AND circuit 52A connecting the output of the relay 1A and the output of the relay 1A is obtained via the OR circuit 6^, and controls the inspection port #I3A. Note that the inspection command 1 is transmitted to the other end.

On the other hand, the opposite end is constructed in the same manner as the own end, but for ease of understanding, the construction of the portion directly related to the explanation of the operation will be explained. Here, the same functions on the own end and the opposite end will be explained with the same number code, but the subscript A will be added to each code.
Or add B to clarify the distinction between the own end and the other end.

At the other end, internal fault detection relay 1B and fault detection relay 2 are installed.
B is connected to the AND circuit 5B, and the inspection command 1 received at the other end is also connected to the NO circuit 5B via the NOT circuit 4B, and when the AND circuit 5B is established, a breaker removal command is given.

Next, its operation will be explained with reference to FIG. 7 and FIG. 9 showing its time chart.

When the automatic inspection is started at the own end, the inspection circuit 3^ outputs 1°° as the inspection command 1. As a result, NOT circuit 4
The output of ^ becomes °0'°, and the AND circuit 5A is controlled to "°0" to lock the 1- and disconnection commands. Also,
Inspection command 1 is also sent to the other end, which receives it and sets the output of L=NOT circuit 4B to O゛^ND times R5
Control B and lock the breaker disconnect command.

When the locking of the breaker disconnection command is completed, inspection command 1 continues to output 1'', and inspection command 20 and inspection command 2 are output.
Outputs ``1''. Inspection command 2 gives an inspection input to internal fault detection relay 1^, checks whether the inspection input amount is a predetermined value, and then changes inspection command 2 to "o".
Immediately after confirming that the inspection input amount has been removed and setting the inspection command 20 to 0", the inspection command 30 and the inspection command 3 are set to 1". Accident detection by inspection command 3 41. @ vessel 2
An inspection input is given to A, and it is checked whether the inspection input amount is a predetermined value, and then inspection command 3 is set to ``0'' to confirm that the inspection input amount has been removed, and inspection command 30 is set to ゛°0. Immediately thereafter, the inspection command 1 is set to 0'° to unlock the disconnect commands for the circuit breaker at the own end and the opposite end, and the automatic inspection is completed. On the other hand, if an accident occurs in the power system during an automatic inspection, the inspection is immediately stopped by an inspection stop command to prevent inspection failures, and the command is unlocked with a disconnection exception. Here, the inspection stop command is detected when a relay other than the one to be inspected operates. In other words, while outputting inspection command 20 (that is, inspecting relay 1A), fault detection relay 2A
The AND circuit 51A operates due to the operation of , and the inspection command 30 is activated.
While outputting (i.e., during inspection of lI! electric appliance 2A), the NO circuit 52^ is activated by the operation of the internal fault detection relay 1A, and an inspection stop command is generated via the OR circuit 6^.

FIG. 8 shows another block diagram of a conventional current differential relay device.

Functions that are the same as those in FIG. 7 are given the same numbers and their explanations will be omitted.

The three signals output via the NO7 circuit 4A of the inspection command 1, which is the output of the internal fault detection relay 1A, the fault detection relay 2A, and the inspection circuit 3A, are connected to the AND circuit 5A, and the circuit breaker disconnection command is set to 4. Inspection command 2 and inspection command 3, which are outputs of the inspection circuit 3A, are controlled to be output on the condition of an inspection permission signal transmitted from the other end, and are configured to give inspection input to relays IA and 2A, respectively. Ru. In addition, the inspection stop command is issued at inspection port 1i1 as in Fig. 7.
Inspection commands 20, 30 and a electric appliance I which are the output of 113A
A, obtained by the output of 2A, controls the inspection circuit 3A. Note that the inspection command 1 is transmitted to the other end, and the inspection circuit 3A is controlled by the inspection permission signal received from the other end.

On the other hand, the opposite end is constructed in the same manner as the own end, but for the sake of simplicity, only the parts directly related to the explanation of the operation will be explained. Note that the subscripts A and B are used in the same way as described above.

At the other end, the circuit for giving the breaker removal command is the same as that shown in FIG. The difference with Fig. 7 is that inspection command 1 is received,
NOT circuit 4B locks the breaker disconnection command.
The point is that the output is inverted by the NOT circuit 42B and sent back as an inspection permission signal.

Next, its operation will be explained with reference to FIG. 8 and FIG. 10 showing its time chart.

When the automatic inspection is started at the own end, the inspection circuit 3A outputs 1° as the inspection command 1. As a result, the input of AND circuit FpfI5A is controlled to "o" via the NOT circuit, and the breaker trip command is locked. Inspection command 1 is also sent to the other end, which receives it and N
The input of the AND circuit 5B is controlled to "o" via the OT circuit 4B to lock the breaker trip command. The locked control of the breaker tripping command is detected when the output of the NO circuit 42B becomes 1'', and is sent back to the starting end of the inspection, that is, to the own end as an inspection permission signal. The own end receives the inspection permission signal sent back from the other end and checks the inspection circuit 3^.
outputs °1゛° to inspection command 20 and inspection command 2.

The following responses until the end of the inspection are the same as in Figure 7.

Furthermore, the procedure for canceling the inspection in the event that an accident occurs in the power system during automatic inspection is also the same as in FIG. 7.

(Problem to be Solved by the Invention) As explained above, in the case of an accident in the power system that occurs during automatic inspection, it is necessary to stop the inspection due to the operation of a relay other than the one to be inspected.

If a system fault occurs while inspecting the internal fault detection relay 1A, the fault detection relay 2A will operate and the inspection can be stopped regardless of whether the system fault is inside or outside the protected area. Not enough. However, the accident detection relay 2A
If a system fault occurs during inspection, use the internal fault detection relay 1A only if the system fault is inside the protected area.
operates and stops the inspection, but if the system fault is outside the protected area, the relay 1A does not operate and does not issue an inspection cancellation command. For this reason, the combination of the inspection input amount and the system fault is erroneously determined to be the inspection input amount, which does not reach the predetermined value, resulting in an inspection failure. In the case of an inspection failure, a lot of time is required to investigate and determine the cause, and during this time the equipment cannot be operated, resulting in a decrease in reliability.

The present invention protects power transmission lines by generating an inspection stop command to stop automatic inspection even if a system accident occurs outside the protection zone during inspection of an accident detection relay, thereby preventing inspection defects. The purpose of this invention is to provide an automatic inspection circuit for a current differential relay device.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention converts the current value at each end into digital data by installing a power transmission line at each end, and converts the current value at each end into digital data. In a current differential relay device that mutually transmits control data indicating the status of control equipment, etc., the operation of the fault detection relay is transmitted as part of the control data, and the operation of the fault detection relay is transmitted to the other end using the data received at one end. By detecting the operation of the accident detection relay at the end, an inspection cancellation command is generated and automatic inspection is canceled.

(Function) If an accident occurs inside or outside the protection zone in the power system during automatic inspection at the own end, the fault detection relay at the other end will operate regardless of the automatic inspection status at the other end. By transmitting the operation from one end to the other end, it is possible to detect that the fault detection relay at the other end has operated, thereby determining a fault in the system being inspected, issuing an inspection stop command, and canceling the automatic inspection.

(Example) Examples will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of an automatic inspection circuit for a current differential relay device according to the present invention.

In FIG. 1, the same parts as in FIG. 7 are given the same reference numerals, and their explanation will be omitted.

The feature of Fig. 1 is that the operation of the fault detection relay 2B at the other end is transmitted to the own end as part of the control data, and the OR circuit indicates that the operation of the fault detection relay 2B of the other end is received at the other end. This is due to the connection to 6^. The other configurations are the same as in FIG. 7.

Next, the effect will be explained.

First, a case will be explained in which an accident occurs outside the protected area during automatic inspection of the own end.

If an external accident occurs while the inspection command 20 is being output, the accident detection relay 2A at the own end and the accident detection relay 2B at the opposite end are activated. Therefore, AND circuit #l51A is established, and at the same time an inspection cancellation command is given through the OR circuit 6A, the operation of the fault detection relay 2B at the other end is also received at the own end, and the inspection cancellation command is checked through the OR circuit 6A. Automatic inspection is canceled by applying to circuit 3^.

Furthermore, if an external fault occurs while the inspection command 30 is being output, the internal fault detection relay 1A at the own end will not operate and the AND circuit 52A will not be established, but the fault detection relay 28 at the other end will not operate.
operates and receives the signal as the received data at its own end, so the inspection stop command is sent to the inspection circuit 3 via the OR circuit 6A.
A, the automatic inspection is canceled.

FIG. 2 is a block diagram of another embodiment of the present invention. In FIG. 2, the same parts as in FIG. 8 are given the same reference numerals, and their explanation will be omitted.

The feature of FIG. 2 is that the output of the NOT circuit 42B is not sent back as is as an inspection permission signal at the other end;
The condition where the output of the accident detection relay 2B is reversed by the NOT circuit 41B is NO times F! ? 153B and returns it as an inspection permission signal, inputs the inspection command 20 and inspection command 30 to the AND circuit 54A via the OR circuit 61^ at the own end, and receives the inspection permission signal from the other end. is input to the AND circuit 54A via the NOT circuit 43A, and the output of the AND circuit 54^ is connected to the OR circuit 6^.

The operation of the embodiment shown in FIG. 2 will be explained in the case where an accident occurs outside the protected area during automatic inspection of the own end.

If an external accident occurs while the inspection command 20 is being output, the accident detection relay 2A at the own end and the accident detection relay 2B at the opposite end are activated. At its own end, an AND circuit 51A is established and an inspection stop command is given to the inspection circuit 3A via an OR circuit 6A. Also, at the other end, the accident detection relay H2B operates and controls the input of the AND circuit 53B to '0' through the NOT circuit 41B, and returns the inspection permission signal as 0', so at the corner of your eye, Output of NOT circuit 43A and OR circuit 61
Both outputs of A become 1', the AND circuit 54A is established, and an inspection stop command is given to the inspection circuit 3A via the OR circuit 6^. Therefore, automatic inspection of the own end is canceled.

If an external accident occurs while the inspection command 30 is being output, the internal accident detection relay 1A at its own end is inoperative and the AND circuit 52
Although A does not hold true, the fault detection relay 2B at the other end operates, so the inspection permission signal becomes 0'' in the same way as above.
An inspection stop command is given to inspection port FN13A, and automatic inspection is canceled.

As is clear from the above explanation, automatic inspection is canceled regardless of whether a system accident during automatic inspection occurs inside or outside the protected area, so it is possible to prevent unnecessary inspection failures from being detected. .

FIG. 3 is a modification of the part of the circuit that generates the inspection cancellation command shown in FIG. The feature is that the output is ORed by the OR circuit 62A and then connected to the 8N circuit 52^.

In the configuration shown in Fig. 3, if a system fault occurs during the automatic inspection at the own end, the fault detection relay at the own end will be activated while the inspection command 20 is being output, regardless of whether the accident occurs inside or outside the protection zone. 2A operates, AND circuit 51^ is established, and an inspection stop command is generated. Also, while the inspection command 30 is being output, in the case of an internal accident in the protected area, it is received that the internal accident detection relay 1^ or the accident detection relay at the other end has operated.
In the case of an accident outside the protected area, the fault detection relay 2 at the other end
Upon receiving that B has operated, AND times F! +52A is established and an inspection stop command is issued.

Therefore, the effect of preventing inspection defects remains the same as in FIG. 1.

FIG. 4 shows yet another modification of the circuit section for generating the inspection stop command shown in FIG. 1, and is characterized by the omission of the AND circuit 52A.

In the configuration shown in FIG. 4, when a system fault occurs during automatic inspection at the own end, while the inspection command 20 is being output, the fault detection relay 2A at the own end operates as in FIG.
is established, or upon receiving that the fault detection relay at the other end has operated, generates an inspection-in-progress command. While the inspection command 30 is being output, whether the accident occurs inside or outside the protection zone, the inspection stop command is generated upon receiving the operation of the accident detection relay at the other end.

Therefore, the effect of preventing inspection defects remains the same as in FIG. 1.

FIG. 5 shows a modification of the part of the circuit that generates the inspection stop command shown in FIG. 2, and in FIG.
The AND circuit 54A is deleted and the signal via the NOT circuit 43A under the condition that the inspection permission signal is received is transferred to the OR circuit 62A.
The feature is that it is ORed with the output of the internal fault detection relay 1A and then connected to the AND circuit 52^.

Even in the configuration shown in Fig. 5, the response when a system fault occurs during automatic inspection at the own end is that when the fault detection relay at the other end operates, the inspection permission signal becomes 0'' and the output of the NOT circuit 43A becomes 1. Therefore, an inspection stop command is generated as in FIG. 3, and the effect of preventing inspection failures cannot be obtained.

FIG. 6 is an example of a modification of the part of the circuit that generates the inspection cancellation command shown in FIG. 5, and is characterized by the deletion of the output of the internal fault detection relay 1^ in FIG.

Even in the configuration shown in Fig. 6, the response when a system fault occurs during automatic inspection at the own end is that when the fault detection relay at the other end operates, the inspection permission signal becomes "o" and the NOT circuit 43A
Since the output becomes "1pa", an inspection stop command is generated as in FIG. 4, and an effect of preventing inspection defects can be obtained.

[Effects of the Invention] As is clear from the above description, according to the present invention, in a current differential relay device that protects a power transmission line, a system fault is detected outside the protection zone during automatic inspection of the fault detection relay at its own end. Even if a failure occurs, the fault detection relay at the other end can respond regardless of the automatic inspection at the other end. Therefore, by adding the operation of this fault detection relay directly or indirectly in combination with a check signal as part of the control data that is originally being transmitted and transmitting it from the other end to the own end, The operation of the fault detection relay at the other end can be detected from the data received at the end, and thereby an inspection stop command can be issued to stop the automatic inspection. Therefore, even if a system accident occurs outside the protected area during automatic inspection, it will not result in a defective inspection, eliminating the need for the time required to investigate and determine the cause when a defective inspection occurs. Since there is no need to stop the operation of the current differential relay device with high reliability, it is possible to provide a current differential relay device with high reliability.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of an automatic inspection circuit for a current differential relay device according to the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, and FIGS. 3 to 6 are diagrams according to the present invention. FIGS. 7 and 8 are diagrams showing examples of automatic inspection circuits for conventional current differential relay devices, and FIGS. 9 and 10 are diagrams showing other embodiments, respectively. It is a figure which shows the time chart of the circuit of a figure. IA, 1B...Internal fault detection relay 2^, 2B・
... Accident detection relay 3A ... Inspection circuit 4A, 4B, 418, 428, 43A...N
OT circuit 5^, 5B, 51A, 52A, 5
3B...AND circuit 6A, 61^, 62A...O
R circuit nephew 2 figure 08 hand hope S chanting 3 figures (opponent 9 wealth power 5 receiving Confucianism 4th concave opponent high power ゛ 憛 to receive negative duck 5 figure 6 figure

Claims (1)

[Claims] A current difference system that is installed at each end of a power transmission line, converts the current value at each end into digital data, and performs protection calculations by mutually transmitting this data along with control data indicating the status of the control equipment at each end. In the dynamic relay device, transmitting the operation of the fault detection relay at the other end as part of the control data,
An automatic inspection circuit for a current differential relay device, characterized in that automatic inspection of the own end is canceled based on data received at the own end.