JPS5930582Y2 - Transport protection relay device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a transport protection relay device that constantly sends out signals and is used to protect power transmission lines, etc., and in particular, it is a transport protection relay device that is capable of detecting defects in various devices that should operate in the event of an abnormality in the transmission line. Regarding protective relay devices.

As is well known, a carrier protection relay device used for power transmission line protection, etc. uses a carrier device to transmit extracted electrical signals from each terminal to each other in waveform, and integrates the electrical signals from all terminals to prevent power transmission line accidents. It detects this and generates a breaker trip output.

However, this type of carrier protection relay device may receive erroneous signals and malfunction when abnormal disturbances occur in the transmission path, especially when waveform transmission is performed using the PCM method or FM method. This is remarkable for things like this.

Therefore, when a transmission line abnormality or a transmission code error is detected, devices have traditionally been locked as soon as possible. If the circuit itself becomes defective, it is impossible to prevent the device from malfunctioning.

Generally, even if such a malfunction occurs, a breaker trip output is generated and the breaker is tripped by an AND condition with a failure detection relay based on another principle as a fail-safe relay, so the breaker is immediately disconnected. However, if the timing of an external failure and the above-mentioned malfunction coincide, erroneous shutoff may occur.

Moreover, such malfunctions are difficult to detect because their occurrence is instantaneous.

The present invention was made in view of the above circumstances, and aims to provide a transport protection relay device equipped with a defect detection device that can reliably detect defects in various devices that should operate when a transmission line abnormality occurs. target

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

FIG. 1 is a block diagram showing the configuration of the carrier protection relay device according to the present invention. Only the terminal portion is shown.

That is, in the figure, MOD is a signal transmission device that receives a digital code transmission signal from the opposite end in a conveyance device, and this signal transmission device MOD converts the analog current signal IRB corresponding to each phase current signal of the opposite end from the transmission signal. ,■s
In addition to generating B and TB, a trip lock command is also generated when an abnormality in the transmission path or an error in the transmitted digital code is detected.

CDR, , CDR2CDR3 are the above current signals IRB,
This is a current differential relay in which ISB and ITB are given separately, and each phase current signal IRA, ISA, and ITA at its own end is given separately, and these current differential relays CDR1 and CDR1.
DR2CDR3 has signals ■RA and IRBIIS, respectively.
A and ISB and ITA and ITB are compared differentially and 1. It generates relay outputs, that is, R-phase, S-phase, and T-phase trip outputs.

In addition, these current differential relays CDR1, CDR2゜CD
R3 locks the output of the trip output when a trip lock command from the signal transmission device MOD is given.

In fact, the current differential relays CDR1, CDR2,
A breaker trip output as the protective relay device is generated by an AND condition between the trip output of the CDR 3 and the failure detection output of a failure detection relay as a fail-safe relay (not shown).

On the other hand, C0NT is a counter that is given the trip outputs of the current differential relays CDR1, CDR2, and CDR3 through the OR circuit OR and counts the trip outputs "1'", and this counter C0NT is set by the timer TIM. When the trip output of the current differential relay CDH is counted two or more times (at least twice) within a predetermined failure detection time, various devices that should operate in the event of an abnormality in the transmission path, that is, the signal transmission device MOD or the current differential relay The defect detection device is configured to generate an alarm output indicating that the locking mechanism in the CDR is defective.

In this case, the three phases of the outputs of the relays CDR1, CDR2, and CDR3 are combined using an OR circuit, because the influence of transmission line disturbances may be felt only on one of the three phases, and two or more phases Although it may extend over several periods, this is to save circuits and monitor them all at once.If you count each phase, you can also check the trip output mechanism of the relay for each phase.

Next, the operation of the conveyance protection relay device of the present invention constructed as described above will be described.

Now, when a digital code transmission signal is given to the signal transmission device MOD from the other end, analog current signals RB, ISB, and ITB corresponding to each phase of the other end are generated, and the current differential relays CDR1, CDR2, J ISA, which is given to each CDR3 separately, while the current signal at its own end is
ITA is also provided to each of the relays CDR1, CDR2, and CDR3.

If an internal fault occurs in the power system in such a state, a trip output u I I + will be generated from the differential operation of each current differential relay CDR, , CDR2゜CDR3. By establishing an AND condition with the failure detection output, a breaker trip output is generated and a breaker (not shown) is tripped.

In addition, a current differential relay CDH for a certain phase of each of the three phases
When a fault occurs in the faulty relay, a trip output 11111 is generated from the faulty relay.

At this time, since no failure detection output is generated, no breaker trip output is generated.

Furthermore, if an instantaneous abnormality such as the above-mentioned disturbance occurs in the transmission path, a change such as a code error will occur in the transmission signal from the other end, so the signal transmission device MOD will detect this abnormality and immediately trip. Generates a lock command to each current differential relay CDR,.

This is to prevent malfunctions of CDR2 and CDR3.

However, the various devices that should operate when this transmission path abnormality occurs, that is, the transmission path abnormality detection circuit and lock command circuit of the signal transmission device MOD, are defective, or the current differential relay C
DR,,CDR2,CDR.

If there is a defect in the locking mechanism that responds to the above trip lock command, the current differential relay CDR.

CDR2 and CDR3 eventually malfunction and generate a trip output n111.

(In this case, only the relay corresponding to the lock mechanism failure generates the trip output T!111.

Further, at this time, since no failure detection output is generated, no breaker trip output is generated.

) and in this state the current differential relay CDR,.

CDR2 and CDR3 operate each time in response to disturbances or instantaneous interruptions that occur in the transmission path that lead to code errors.

In general, abnormalities and disturbances in the transmission path as described above occur with a certain frequency, and are often temporary.

Therefore, if there is a failure in the locking mechanism in response to an abnormality or disturbance in the transmission path, the erroneous output is instantaneous, and the frequency of occurrence is considered to be linked to the abnormality or disturbance in the transmission path.

Now, the trip output "1" in each of the above-mentioned situations is outputted to the counter C0NT via the OR circuit OR, and the number of outputs is counted.

Then, if this count number is 2 or more times within the predetermined failure detection time set by timer TIM, count C0
An alarm output is generated from the NT, and the signal transmission device MOD
An alarm is output to the effect that the transmission path abnormality detection circuit, lock command circuit, and locking mechanism of the relay are defective, that is, the various devices that should operate when the transmission path is abnormal are defective.

That is, as mentioned above, '1' via the OR circuit OR
'' trip output is also applied when there is an internal failure in the system and when the current differential relay CDR is defective.

However, in this case, first of all, when there is an internal failure in the system, the trip output of the current differential relay CDH is temporarily switched to the counter C
Also, most defects in the current differential relay CDH are usually continuous, and once they become defective, they remain in that state, and the trip output is continuously output to the counter C0NT. .

Therefore, in these cases the counter CUNT is the timer TIM
The counting operation is performed only once within the predetermined failure detection time set by , and no alarm output is generated.

On the other hand, as mentioned above, abnormalities and disturbances in the transmission line occur with a certain frequency and are temporary, so if the various devices that should operate at the time of an abnormality in the transmission line are defective, the current differential relay A trip output of 11111 from the CDR is output to the counter C0NT on the second recovery.

As a result, the counter C0NT will perform a counting operation more than once within the predetermined failure detection time set by the timer TIM, and an alarm will be output, indicating that there is a failure in the transmission line and the locking mechanism for it. Detected.

In this way, in this embodiment, the current of each terminal is transmitted in waveform to each other using a transfer device, and the current signals of all terminals are applied to the current differential relay CDH and compared, thereby determining an accident and generating a trip output. The breaker trip output is generated by the AND condition of this and the failure detection output from the failure detection relay, and when the transmission path is abnormal, the current differential relay CD
In a current differential transfer protective relay device configured to lock the trip output of the current differential relay CDR, a counter C0NT counts the number of trip outputs of the current differential relay CDR, and this count is set to a predetermined value set in advance by a timer TIM. If the number of failures occurs twice or more within the failure detection time, an alarm will be output to indicate that the various devices that should operate when the transmission line is abnormal are defective. Moreover, it can be detected reliably, thereby greatly contributing to the stable operation of the protective relay device.

In the above embodiment, the current differential transfer protection relay device using the PCM transmission method was described as 1], but there is generally a risk of malfunction due to disturbance in the signal transmission path, and it is necessary to prevent erroneous cutoff. The present invention can also be applied to a transportation protection relay device having a trip output lock circuit.

Further, as shown in FIG. 2, as an input configuration to the counter C0NT in the above embodiment, the fault detection output of the fault detection relay used as a fail-safe relay is used as an inhibit input, and the output of the above OR circuit OR is gate-operated. The output of the AND circuit AND is sent to the counter C0NT.
It goes without saying that the above-mentioned failure detection can also be carried out by inputting a signal into the circuit and counting the number of trip outputs when the failure detection relay that detects a system failure does not detect a failure.

It goes without saying that other modifications may be made as appropriate without changing the gist of the invention.

As detailed above, according to the present invention, it is possible to provide an extremely reliable transport protection relay device that is equipped with a defect detection device that can reliably detect defects in various devices that should operate when a transmission line abnormality occurs. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the conveyance protection relay device according to the present invention, and FIG. 2 is a block diagram showing another embodiment according to the present invention. MOD... Signal transmission device, CDR, CDR2
゜CDR3・・・・・・Current differential relay, OR・・・・
...OR circuit, AND...AND circuit, C0N
T...Counter, TIM...Timer.

Claims (1)

[Scope of utility model registration request] A transport device is used to transmit the electrical signals extracted from each terminal of the power system to each other, and a protective relay determines an accident based on the electrical signals of all terminals, and a trip output is output and a fault detection relay detects a system failure. In a transport protection relay device that generates a breaker trip output based on an AND condition with a detection output, and is equipped with a device that operates when a transmission line abnormality occurs to lock the trip output of the protective relay, a predetermined failure detection time is set in advance. A set timer is used to count the number of trip outputs of the protective relay, and on the condition that this count is 2 or more times within the time preset by the timer, the various devices that should operate when the transmission line is abnormal. A conveyance protection relay device comprising: a counter that generates an alarm output indicating a defect; and a defect detection device for detecting a defect.