JPS6251054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a power line carrier pilot protection relay device using a frequency shifting method (hereinafter referred to as FS method), which is constructed using, for example, an internal and external directional relay.

Various types of protective relay devices are used to protect power systems, and one of them is a pilot protective relay device because it is capable of removing faults at high speed. This pilot protection relay device protects the protected section by mutually transmitting the failure status between the respective terminals of the protected section to determine the failure. A direction comparison pilot relay device will be described below as an example.

In this directional comparison pilot relay device, in the event of an accident within the protected area, the internal directional relays installed at both terminals operate, planning to disconnect or trip the own terminal, and send a trip permission signal to the other terminal as a carrier wave. The system is protected by tripping the circuit breaker under the AND condition of the tripping intention of the own terminal and the reception of the tripping permission signal from the other terminal. In addition, in the event of an external fault, the terminal from which the fault current flows out will not attempt to trip its own terminal, and will transmit a trip prevention signal to the other terminal as a carrier wave, since the internal relay will not operate and the external relay will operate. Therefore, the AND condition between the intention to trip the own terminal and the receipt of the trip permission signal from the other terminal is not satisfied at both terminals, and the breaker is not tripped.

By the way, in such a direction comparison pilot relay device, when the carrier wave used therein and the frequency used for the telephone line are used in the same voice band, the following problem occurs. This point will be specifically described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a conventional direction comparison pilot relay device in a direct grounding system, and in the figure, A and B are terminals. 1a, 1
b is a bus bar of each terminal A, B, which is interconnected by a power transmission line 2 via each end and disconnectors 3a, 3b. Further, 4a and 4b are CTs that detect the respective terminal currents, and 5a and 5b are the respective terminal busbars 1a and 1b.
PT (or PD), 6a, 6b to detect the voltage of
are respectively CT4a and PT5a, CT4b and PT5b
This is a directional comparison pilot relay consisting of internal and external directional relays that performs fault judgment based on each detected electrical quantity. On the other hand, fa and fb are carrier wave signals sent from a carrier wave transmission circuit (not shown) provided in each direction comparison pilot relay 6a, 6b, including a tripping prevention signal (hereinafter referred to as _F1 signal) and a tripping permission signal. (hereinafter referred to as the F ₂ signal) can be transmitted.

In such a configuration, in the case of power line transport using the FS method, under normal conditions, each terminal A and B transmits a continuous F ₁ signal to each other to prevent the transport from tripping, and normally this continuous F ₁ signal does not interfere with the telephone line. I try not to make it worse. On the other hand, in the event of an accident within the protection zone as shown at point F in Figure 1, the
Since the F ₂ signal is transmitted to the mating terminals B and A through the fault point F, the F ₂ signal is attenuated at F and the trip intention condition may not be satisfied. Therefore, in order to ensure that the F ₂ signal is transmitted to the other party's terminal, the F ₂ signal is generally amplified by an amplifier before being transmitted.

Furthermore, in the power system shown in Figure 1,
In case of an F-point accident when either terminal A or B is at rest, in order to transport and trip the other terminal's breaker, at the rest terminal, the breaker is opened according to the breaker opening condition. , the _F2 signal is amplified and transmitted continuously. At this time, when using the carrier wave in the voice band as mentioned above, it is necessary to use a telephone line to amplify the _F2 signal with an amplifier and transmit it so that the signal can be reliably transmitted to the other party's terminal. Can not. In other words, with the conventional means of amplifying and continuously transmitting the _F2 signal for the purpose of carrying out tripping when the breaker is opened, the problem is that it becomes impossible to use the telephone line. occurs.

The present invention was made in view of the above circumstances, and its purpose is to make it difficult to use telephone lines even when one terminal is out of service in a power system consisting of a plurality of terminals. It is an object of the present invention to provide a pilot protection relay device that can eliminate accidents within a protection zone at high speed by transport tripping without any problems.

An embodiment of the present invention will be described below with reference to the drawings. Figures 2a and 2b show in block form an example of the configuration of the direction comparison pilot relay device according to the present invention, where a shows the configuration of the _F2 carrier control circuit and b shows the configuration of the tripping circuit, respectively. be. In addition, each circuit of FIG. 2a and b is as described above.
These are separately provided in the direction comparison pilot relays 6a and 6b on the terminals A and B sides in FIG. 1, respectively. First, in Fig. 2a, 7 is an internal direction relay, AND1 is an AND (logical product) in which the F ₂ signal reception condition signal S8 from the other terminal and the open condition signal S9 of the disconnector 3 of the own terminal are input. ) circuit, 1
0 is a one-shot circuit which is operated by the AND output of this AND circuit AND1 and sends out its output for a predetermined time T. Further, OR is an OR circuit which receives the output of the internal directional relay 7 and the output of the one-shot circuit 10 as inputs, and the output of the _OR condition stops the transmission of the F1 signal from the _F1 signal transmission circuit (not shown). , and is configured to control the F ₂ signal transmission circuit 11 and send out the F ₂ signal S13 via the amplifier 12. On the other hand, in Figure 2b
AND2 is an AND circuit which inputs the output of the internal directional relay 7 and the _F2 signal reception condition signal S8 from the other terminal, and sends out the AND condition output as the trip output S14 of the breaker 3 of its own terminal. Configure it to do so.

Next, the operation of the direction comparison pilot relay device constructed as described above will be described. In the system as shown in FIG. 1, normally each terminal A and B continuously transmits the _F1 signal to the other terminal, so that transport tripping is not performed. Now, if an accident within the protection zone occurs at point F in FIG. 1 in such a state, the internal direction relays 7 of each terminal A and B detect this and operate. Then, since the operating output of this internal directional relay 7 is given to the OR circuit OR, the OR output stops the transmission of the F ₁ signal at each terminal A and B, and controls the F ₂ signal multiplication circuit 11. The _F2 signal is amplified by the amplifier 12 and transmitted to the opposite ends B and A.
As a result, on each terminal A, B side, an AND condition is established between the output of the internal direction relay 7 of the own terminal A, B and the _F2 signal reception condition output from the opposite terminal B, A side, and the AND circuit AND2 Output S14 of
As a result, the disconnectors 3a and 3b of the terminals A and B are tripped, and the accident is eliminated.

Next, in the above, the terminal B side is connected to the disconnector 3.
In a state where the terminal B is at rest with the terminal B open, the terminal B continuously transmits the _F1 signal. In such a state, if an accident within the protection zone occurs at point F in FIG. 1, the internal direction relay 7 on the terminal A side detects this and operates. Then, since the operational output of this internal directional relay 7 is given to the OR circuit OR, the F ₂ signal is amplified by the amplifier 12 and transmitted to the other terminal B side instead of the F ₁ signal in the same manner as described above. On the other hand, at the other terminal B which is the rest end, the _F2 signal reception condition output from the terminal A side is output S8.
The AND condition with the open condition output S9 of the self-terminal circuit breaker 3b is established, and the output of the AND circuit AND2 is given to the one-shot circuit 10. As a result, the one-shot circuit 10 operates and its output is applied to the OR circuit OR for a predetermined time T.
Then, in the same manner as described above, the _F2 signal is amplified by the amplifier 11 instead of the _F1 signal and transmitted to the other terminal A side only during this time T. As a result, on the terminal A side, the output of the internal direction relay 7 of its own terminal A,
The AND condition with the _F2 signal reception condition output S8 from the terminal B side, which is the rest end, is established, and the AND circuit
The output S14 of AND2 trips the circuit breaker 3a of its own terminal A, and the accident is eliminated. In this case, the terminal B which is inactive in the above case is controlled to transmit F by the AND condition established between the open condition output S9 of the own terminal and disconnector 3b and _the F2 signal reception condition output S8 from the other terminal A. ₂ The time it takes to amplify the signal and send it back to terminal A is a very short time T, so there is no effect on telephone line usage.

In this way, a two-terminal power transmission line system interconnected by the power transmission line 2 via the breakers 3a and 3b is normally used to send the _F1 signal to the other terminal, and in the event of an accident, the internal directional relay 7 is activated. To the other terminal due to operation
The F ₂ signal is amplified and transmitted, and the AND condition is established between the operating condition of the internal direction relay 7 at the own end and the receiving condition of the F ₂ signal from the other terminal, and the breaker 3a, 3b is activated.
In the direction comparison pilot relay system using the FS method, which eliminates accidents by tripping the terminal, the open condition signal S9 of the breaker 3 on the own terminal side and the open condition signal S9 of the breaker 3 on the own terminal side are connected to the above A or B terminal side, which is the rest end. F ₂ from
Signal reception condition AND condition with signal S8 AND1
One-shot circuit 10 is established on the condition that
Accordingly, an F ₂ transmission control circuit is provided which amplifies the F ₂ signal with an amplifier 12 for a predetermined time T and transmits it to the other terminal side.

Therefore, in the event of an accident F within the protection zone of transmission line 2 when one end is inactive, the conditions for opening the breaker
Due to the AND condition with the _F2 reception condition, the time it takes to amplify and return the _F2 signal from the resting end to the other terminal is T, which is a very short time, so carrier wave transmission is performed when one terminal is resting. Even if the control is carried out, it is possible to remove the accident F within the protection zone of the power transmission line 2 at an extremely high speed without making it difficult to use the telephone line. Also,
The FS method can be fully utilized to provide highly reliable transmission line system protection.

In the above embodiment, the present invention is applied to a direction comparison pilot protection relay device, but other applications such as controlling the transmission of the _F2 signal to the other terminal under the condition of the idle end or the disconnector opening condition are described. This method can be similarly applied to the pilot relay device of the above method.

In addition, it goes without saying that the present invention can be modified and implemented in various ways without changing the gist thereof.

As explained above, according to the present invention, on the side of the terminal that becomes the dormant terminal, the F ₂ signal is transmitted to the other party for a predetermined period of time by establishing the AND condition between the disconnection open condition of the own terminal and the F ₂ signal receiving condition from the other terminal. Since it is configured to send data to the terminal, even if one terminal is out of service, accidents within the protected area can be removed at high speed by transport tripping without making it difficult to use the telephone line. An extremely reliable pilot protection relay device can be provided.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a direction comparison pilot protection relay device in a direct earthing system, Figure 2 a and b
FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. 3a, 3b...Shield breaker, 6a, 6b...Direction comparison pilot relay, 7...Internal direction relay,
S8, S9...condition signal, 10...one shot circuit, 11... _F2 transmission circuit, 12...amplifier,
S13... _F2 signal, S14...trip output signal, AND1,2...AND circuit, OR...OR circuit.

Claims (1)

[Claims] 1 In a power system consisting of multiple terminals interconnected by a power transmission line via a power line disconnector, in the event of a system fault, each terminal transmits a trip permission signal to the other terminal, and the fault detection conditions at one end and the other end are determined. In a pilot protection relay device that protects the terminal by tripping the circuit breaker on the own terminal side based on an AND condition with the trip permission signal from the terminal, the circuit breaker of the terminal is connected to the terminal side that is the rest end. A pilot protection relay device comprising a device that transmits a trip permission signal to a partner terminal for a predetermined time based on an AND condition of an open condition and a trip permission signal reception condition from the partner terminal.