JPH04190620A - Halt end control system for protective relay - Google Patents

Abstract

PURPOSE:To prevent device lock at an operating end in case of defective receiving data at a halt end by controlling the other end as a halt end at its own end if a data received at the other end is defective. CONSTITUTION:When a data received at end B is defective, a NOT circuit 3 outputs an output 0, AND circuits 5, 6 also output 0 and thereby the output at terminal Q of an F/F circuit 7 is 0. Since a NOT circuit 9 has output 1, an AND circuit 10 also has output 1 and a defective transmission circuit 11 decides a defective transmission and locks a device. When a forcible control circuit 12 is operated under that state, an AND circuit 13 has output 1 and an OR circuit 14 also has an output 1. Input terminal S of the F/F circuit 7 has 1 while input terminal R thereof has 0 and the output terminal Q has 1 and thereby decision of terminal B halt is made. Consequently, the AND circuit 10 has an output 0 and the defective transmission circuit 11 does not perform detection of defect and the device is unlocked.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a dead end control method for a protective relay device.

(Prior Art) A current differential relay detects a fault point current from the current value of each terminal, and can be applied not only to two-terminal power transmission lines but also to multi-terminal power transmission lines. To do this, it is necessary to transmit the current waveform of each terminal to the other terminal, and in a digital relay system, the instantaneous value data of each terminal current is converted into a digital quantity, encoded, and converted into PCM (PuQse Code Mod).
lation) is being transmitted to the other end in the transmission direction. A digital current differential relay is constructed with a microcomputer that collects and processes the transmitted current data of each terminal in this way. For this reason, by synchronizing data sampling at each terminal of the power transmission line and extracting data at the same time from each terminal, and adding this data, it is possible to obtain an accurate difference current without performing operations such as compensating for transmission delays. There is.

There are two methods for achieving sampling synchronization: one is to simultaneously sample the current at each terminal based on the synchronization signal generated by the signal terminal station, and the other is to have the sampling synchronization function on the same layer as the relay side. Since the difference between the two systems is not related to the purpose, the explanation will be omitted, and only the latter configuration will be explained with reference to FIG.

In FIG. 2, the input converter 31 is a current transformer CT at the A terminal.
-1, the system electricity quantity iL is inputted, introduced into the analog input crab unit 32, passed through the analog filter 33, and then sampled and held circuit (S/H) 34 and analog/digital converter (A/D) 35. is converted into digital data at every predetermined sampling synchronization, and sent to the transmission control unit 37 and the arithmetic unit 4 via the system bus 36.
1 will be introduced. In the transmission control unit 37, parallel
The serial conversion circuit (P/5) 38 transmits data to the other end via the transmission device. The data at the other end is sent to the serial/parallel conversion circuit (S/P) 39 via the transmission device.
and is introduced into the arithmetic unit 41 via the system bus 36. Sampling synchronization control circuit (SYN
C) 40 is a sample and hold circuit (S/H) 3 to match the sample synchronization between the sample and hold circuit (S/H) 34 and the serial/parallel conversion circuit (S/P) 39.
The sampling timing of step 4 is controlled. The arithmetic unit 41 adds the data of the digital converter (AD) 35 and the data of the serial/parallel converter 39, and issues a command to trip the circuit breaker CB-1 when the difference current exceeds a set value.

FIG. 3 shows a transmission format for sending information from each terminal used in the PCM transmission system, and is an example of the format applied to the 60 Hz system. 1 super frame (16
, 67F) consists of 900 bits, and 1 frame = 7
The 5 bits consist of 6 bits of frame synchronization signal, 36 bits of instantaneous value data of each terminal current (3 phases of 12 bits).
, 12-bit control signal (control signal sends breaker on/off information, inspection command information, synchronous control signal, etc.)
and CRC check signal (CycJic Redan)
dancy Check). CR
The C-check signal is a system generally used to detect code errors in communications, and this device detects errors in received No. 4 to reliably detect single-bit defects. Further, the control signal controls frame synchronization and sampling synchronization, and detects a failure when synchronization is not achieved. When a code error or synchronization failure is detected in the CRC check, it is generally determined that the received data is defective, and the device is locked and an alarm is displayed. Furthermore, even when the power is turned off, the control signal cannot be sent, so it is determined that the received data is defective.

FIG. 4 shows the case of the A terminal in a conventional rest end control circuit. 1 is a CF detection circuit (received data failure detection circuit), 2 is a CB (L or disconnection) empty detection circuit at the B end, 3 and 4 are N07 circuits, and when CF detection circuit 1 detects a defect, N01 circuit 3 is activated. When the output 01CB disconnection detection circuit 2 detects disconnection, the NOT circuit 4 becomes the output O. 5 and 6 are AND
In the circuit, when the output of the N01 circuit 3 is 1, the AND circuit 5 outputs 1 when the CB cutting/cutting circuit 2 detects disconnection, and the AND circuit 6 outputs 1 when the disconnection is not detected. 7 is F/
Input terminal S is 1 and R is F circuit (flip-flop circuit).
When is O, the output terminal Q becomes an output 1, and it is determined that the B end is stopped. When input terminal S is O and R is 1, output terminal Q outputs 0.
Therefore, it is determined that it is B-end operation. Further, when the input terminals S and R are both O, the output terminal Q holds the previous value. 8 is B
The end current zero control circuit determines that the B end is stopped when the Q output of the F/F circuit 7 is 1, and controls the received current data at the B end to zero. 9 is a N07 circuit, and when the Q output of the F/F circuit 7 is 1, the output becomes O. 10 is an AND circuit which is detected by the CF detection circuit 1, and becomes output 1 when the output of the OR circuit 9 is 1 during B-terminal operation. Reference numeral 11 denotes a transmission failure detection circuit, which determines that there is a transmission failure and locks the device if the output of the AND circuit 10 becomes 1 when the received data at the B end is good.

FIG. 5 is a diagram for explaining the operation of a conventional rest end control circuit. The operation of the rest end control circuit shown in FIG. 4 in the protection system shown in FIG. 5 will be described below.

FIG. 5 shows a case where both the A and B ends have CB input and the B end reception data is normal. At this time, neither the CF detection circuit 1 nor the CB cutout circuit 2 is detected, so the AND circuit 5 outputs O and N
Since both circuits 3 and 4 output O, the output of AND circuit 6 is 1,
Therefore, since the input terminal S of the F/F circuit 7 is 0 and the input terminal R is 1, the output terminal Q becomes an output O, and it is determined that the B-end operation is performed. Therefore, the B-end current zero control circuit 8 does not perform zero control of the B-end current data. Also, since the received data at the B end is normal, AND
The output of the circuit 10 becomes 0, and the transmission failure detection circuit 11 does not detect a transmission failure.

FIG. 5 (■) shows the case where the B-end CB cutting operation is performed from the above-mentioned state (2). At this time, the CB cutout circuit 2 is detected, and the A
In order to control the ND circuit 5 to output 1 and the AND circuit 6 to output 0, the input terminal S of the F/F circuit 7 is controlled to 1. Since R is 0, the output terminal Q becomes an output 1, and it is determined that the B end is stopped, and the B end current zero control circuit 8 performs zero control of the current data at the B end.

FIG. 5 (■) shows a case where the received data at the B end becomes invalid due to the B end power being turned off from the above state (2). At this time, both the CF detection circuit 1 and the CB cutout circuit 2 are detected, but NO
Since the T circuit 3 has an output of 0, both AND circuits 5 and 6 have an output of 0. For this reason, the input terminals S and R of the F/F circuit 7 are both 0, and the output of the output terminal Q holds the previous value, so the output becomes 1, which is the same as the state shown in Figure 5 (■), and it remains determined that the B end is stopped. . Therefore, even if the CF detection circuit 1 detects it, it will be NO because the B end is stopped.
The T circuit 9 has an output of 0, and the AND circuit 10 has an output of 0. Therefore, even if the received data at the B end is defective, the transmission failure detection circuit 11 does not detect it as a transmission failure.

(Problem to be solved by the invention) FIG. 6 is a diagram for explaining the problems of the prior art.

In Fig. 6 (■), the protection function itself has stopped because the CB is disconnected at both ends A and B, and the power is turned off.

Figure 6 (■) shows the case where the A-terminal power source is switched from the above-mentioned state (■). Since the protection function of the A end is working normally, a reception data failure of the B end is detected. At this time, the CF detection circuit 1 detects the output, the NOT circuit 3 outputs O, and the AND circuits 5 and 6 output O, and the output terminal Q of the F/F circuit 7 retains its previous value.
Normally, in the rest end control method of a digital current differential relay, when turning on the power from OFF, the initialize function activates the F/
The output terminal Q of the F circuit 7 is set to the output O and B-end operation. Therefore, the B end of the previous price will be used.

Therefore, the CF detection circuit 1 detects it, the NOT circuit 9 outputs 1, the A N'D circuit 10 outputs 1, and the transmission failure circuit 11 determines that there is a transmission failure and locks the device.

Figure 6 (■) shows a case where one-end operation is performed with A@CB person from the above-mentioned state (■), and it is determined that there is a transmission failure and the device remains locked. Therefore, even if an accident occurs in sections A and B,
With the protection device at the end, the CB cannot be tripped and the accident cannot be removed.

If you perform the operations shown in Figure 6 ■ to ■ in this way, the device will remain locked, so you must always follow the steps shown in Figure 5 ■ to ■. However, the operations shown in Figure 6 may also be performed. This is possible, so when there is a power failure at the 10,000-B terminal, B@
Even if an attempt is made to operate only the A end by a CB person with the CB turned off, the B end CB will be turned off after detecting a fault in the received data, and the A end will detect a transmission failure and lock the device, so it cannot be expected that the protection device will eliminate the accident.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an inactive end control method for a protective relay device that does not cause the operating end to lock up when the received data at the inactive end is faulty.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for controlling the idle end of a digital current differential relay provided at each terminal in order to protect a multi-terminal power transmission line. When the data is good, the terminal is configured so that other terminals can be controlled as if they are at rest.
In the present invention, as a result of forcibly controlling the idle end of the receiving data channel under controlled conditions, it has become possible to prevent the active end from being improperly locked due to transmission failure through the CB operation procedure of the system.

(Example) The present invention will be explained in detail below with reference to FIG.

Although FIG. 1 describes the case of the A terminal, the B terminal also has a similar configuration. In addition, in Figure 1, the 4th
The same parts as those in the figure are given the same reference numerals.

In FIG. 1, reference numerals 1 to 11 have the same functions as those in FIG. 4, so explanations thereof will be omitted, and only portions that are different from those in FIG. 4 will be explained. Reference numeral 12 is a four-circuit circuit that is controlled by a changeover switch or a changeover terminal. 13 is an AND circuit, which is detected by the CF detection circuit 1 when the B-end received data is good, and forcibly connects the four circuits 1 to 4.
When controlled with 2, the output is 1. 14 is an OR circuit
When the output of either D circuit 5 or 13 is 1, the output becomes 1. Also, since the forced four circuit 12 is not normally controlled, A
The ND circuit 13 has an output of 0. Therefore, the F/F circuit 7 is controlled only by the AND circuits 5 and 6 as in FIG. Therefore, in the cases shown in FIGS. 5-5, the same operations as in FIG. 4 are performed.

Next, in the case of Fig. 6 (■), which was a problem with the conventional device, the NOT circuit 3 outputs O because the B end received data is faulty, and the A
The outputs of the ND circuits 5 and 6 are O.

Also, the input terminals S and R of the F/F circuit 7 are both O, and the output terminal Q
In order to maintain the previous value, the output is set to O for B-end operation. At this time, the CF detection circuit 1 detects a failure, and the NOT circuit 9 has an output of 1 due to B-terminal operation, so the AND circuit 10 has an output of 1, and the transmission failure circuit 11 determines that there is a transmission failure and locks the device.

If the four circuits 12 are forcibly controlled in this state, the AND circuit 13 will have an output of 1 because the CF detection circuit 1 has detected it, and the OR circuit 14 will also have an output of 1. Therefore, F/F circuit 7
The input terminal S of the input terminal S is 1, and the input terminal R is O, so that the output terminal Q of the output terminal Q is 1, and it is determined that the B end is stopped.

Therefore, the B-terminal current zero control circuit 8 controls the received data at the B-terminal to zero, and the NOT circuit 9 outputs O, so the AND circuit 10 outputs O, and the transmission failure circuit 11 does not detect a failure and locks the device. will also be canceled.

〔Effect of the invention〕

As described above, according to the present invention, since the idle end control can be performed under forced control conditions at the active end, it is possible to perform the idle end control that allows the device to be unlocked without any operational restrictions.

[Brief explanation of drawings]

Fig. 1 is an embodiment circuit diagram for explaining the dead end control method according to the present invention, Fig. 2 is a configuration diagram of a digital current differential relay, Fig. 3 is a transmission format of the transmission method, and Fig. 4 is a conventional one. The rest end control circuit diagrams of FIGS. 5 and 6 are diagrams for explaining the operation of rest end control. 1... Received data error detection circuit 2... CB disconnection detection circuit 3.4.9... NOT circuit 5, 6.10.13... AND circuit 7... Flip-flop circuit 8... Reception current zero control circuit 11...Transmission failure detection circuit 12...Forced four circuit 14...OR circuit Agent Patent attorney Noriyuki Chika Figure 1 C Hatoko Figure 4 Afil B end A end power supply λ B End power supply A connection V power supply input B power supply, input Figure 5

Claims (1)

[Claims] In the idle end control method of a current differential protection relay device installed at each terminal to protect a multi-terminal power transmission line, the other terminal is controlled to be treated as an idle end while a transmission failure is detected at the other terminal. A rest end control method for a protective relay device.