JPS60200724A - Protective relaying unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a protective relay device with an improved automatic monitoring function.

[Technical Background of the Invention] Reliability of the protective relay device is an extremely important element. Most of today's protective relay devices, which are mainly static relays, are equipped with automatic monitoring functions to improve device reliability.

The automatic monitoring function consists of a constant monitoring function and an automatic inspection function.Continuous monitoring issues an alarm when a condition different from normal has continued for a certain period of time, and is mainly used to detect malfunctioning relays. . On the other hand, automatic inspection involves applying a predetermined inspection input to a relay at a fixed inspection period and observing its response, and mainly detects defects on the side of the relay that malfunctions.

However, some relays that are subject to automatic monitoring can be in both a constantly operating mode and a constantly non-operating mode even if only J is defective. It is not possible. For example, in an undervoltage relay that detects a system failure when the system voltage drops below a certain voltage, the protected system outputs a short-term operating force ( However, when the protected system is not being charged during system switching or stoppage, it is in a state where the operating output is constantly output during a so-called total outage.Therefore, it is difficult to determine whether the undervoltage relay is malfunctioning and is operating. Otherwise, automatic monitoring cannot be performed unless it is determined whether the system is operating normally.

By the way, recent automatic inspection methods often use a method in which a check input is given, the relay to be inspected is checked to see if it operates, and after the operation, the check input is turned off and the relay is checked until it returns to normal, before proceeding to the next check step. There is. This is based on the concept of preventing two or more relays from operating at the same time during automatic inspection as much as possible, and when an automatic inspection fails to restore the relay, an alarm is not issued as an automatic inspection failure. For this reason, during a total power outage, there is no need to check the operation if the undervoltage relay is constantly operating, and it is also impossible to confirm recovery, so during a total power outage, the undervoltage relay is not inspected and only the inspection step is performed. A method of making so-called empty steps is used.

Normally, as a total failure detection method for an undervoltage relay, in an undervoltage relay equipped with three phases (R, S, and T phases) of detection elements, when all three phases continue to operate for a certain period of time or more, it is determined that a total failure has occurred.
A method is usually used in which when one-phase or two-phase operation continues for a certain period of time or more, it is determined to be defective and an alarm is issued. In addition, the protective relay system for ultra-high voltage systems is equipped with an undervoltage relay for detecting ground faults and short circuits, so in such cases, if both ground faults and short circuits continue for a certain period of time, a total power outage will occur. A method is usually used in which a ground fault or a short circuit is determined, and if either ground fault or short circuit continues for a certain period of time, it is determined to be defective and an alarm is issued.

[Problems in the Background Art] Two methods of automatically inspecting the above-mentioned undervoltage relays are: for undervoltage relays equipped with three phases of detection elements, one method is to apply inspection input to each phase to check the response, and the other is to confirm the response by inputting inspection input to each phase at the same time. In addition, a method of confirming response is also used, but recently the latter method has been increasingly used from the viewpoint of reducing the number of inspection circuits and shortening inspection time. Even when an undervoltage relay for detecting ground faults and short circuits is provided, a method of simultaneously checking for ground faults and short circuits is used for the same purpose. However, when the above-mentioned total failure detection method is used, all three phases or both the ground fault and short circuit operate during automatic inspection, and the apparent operation is exactly the same as the upper total failure. For this reason, in the past, the full-stop detection time was made longer than the inspection defect detection time to prevent the vehicle from idling because it was determined to be a full-stop during an inspection traffic jam due to an inspection defect. However, if you are equipped with a device that requires a long automatic inspection time, such as a medium-speed recirculation device or backup protection device, the inspection failure detection time will also be longer, so the total stop detection time should be lengthened accordingly. did not become. For this reason, the time for locking the constant monitoring circuit of the undervoltage relay at full stop is delayed, so the constant monitoring detection time must be lengthened accordingly. As a result, the accuracy of the constant monitoring failure detection time is reduced, and the response when a failure occurs is delayed, which is a factor that reduces the reliability of the device.

In addition, it is very complicated to change the total failure detection time and the continuous monitoring failure detection time each time depending on the equipment to be inspected.

[Objective of the Invention 1 The present invention has been made with the aim of solving the above-mentioned problems, and is capable of automatic inspection without changing the full stop detection time each time by occupied slow inspection, and is equipped with an automatic inspection. The purpose of the present invention is to provide a protective relay device that can prevent functional deterioration caused by

[Summary of the Invention] In the present invention, when a check input is applied to a protective relay device including an undervoltage relay, if a total failure has already been detected, the total failure detection circuit is not locked and the total failure is detected. The system attempts to lock the total stop detection circuit only when the system is not in use.

[Embodiment of the Invention] The configuration of an automatic monitoring circuit and an embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the inspection step circuit, 81
~Sn is each inspection step signal, x1~Xn is the output of the relay to be inspected corresponding to each inspection step. 1 to 4 are AND circuits, 5 is a leaf circuit, and 6 is a step circuit, with Sl and ×1
. . . When which AND condition of 3n and The inspection steps are controlled to proceed sequentially from 81 to 3n.

The AND circuit 4 detects a full stop, produces an output during the undervoltage relay inspection step S1, and controls the step circuit 6 to instantaneously advance the step from 81 to 82, thereby performing a so-called idle step. FIG. 3 shows an inspection input application circuit, where S and T are voltages obtained by applying the protected system voltage via a voltage transformer.

7 is the N01 circuit, 8 is the AND circuit, and when the output x 1 of the undervoltage relay is not output, the output horn of the N01 circuit 7 is "
1" level, the step signal S1 causes the AND80
A circuit output is generated and auxiliary relay 9 operates. 9A is a normally closed contact that opens when auxiliary relay 9 operates; 10
is an undervoltage electric appliance with three phases (R, S, and T phases) of detection elements, and it is in an inactive state when the R, S, and H voltages are applied, but the R, S, It operates when the voltage of H drops below a certain value or when the vehicle inspection contact 9A is circuited. Figure 4 shows a constant monitoring circuit, where Y1 to Yn are each
ll! Electrical output, 11μNOT circuit, 12.14 is A
ND circuit, 13 is an OR circuit, and 15 is a time-limited operation circuit for constantly monitoring failure detection. When the output Y1 of the undervoltage relay is not detected as a complete stop, or if each of the outputs Y2 to Yn continues for a certain period of time or more,
On the condition that the AND circuit 14 is not inspecting, after the settling time of the time-limited operation circuit 15 has elapsed, it is determined that the constant monitoring is defective and an alarm is issued.

At this time, if inspection is in progress, the AND circuit 14 is locked,
The time-limited operation circuit 15 is not activated and no alarm is issued.

Figure 5 shows the inspection defect detection circuit, with 16 being the 801 circuit and 17 being the 801 circuit.
．． 18 is an AND circuit, 19 is an OR circuit, and 20 is a time-limited operation circuit for detecting inspection defects. The OR shown in Figure 1 was checked during inspection.
When the output oP of the circuit 5 does not change for a certain period of time or more and remains at the "1" level, an output from the AND circuit 17 is generated and sent via the OR circuit 19 to the time-limited operation circuit 20 after the settling time, and an inspection error is detected.
It is determined to be good and an alarm is issued. When OP is at the rOJ level, the NO101 circuit 1 output goes to the "1" level, an output from the AND circuit 18 is generated, and an alarm is issued via the OR circuit 19 after the settling time of the time-limited operation circuit 20. In this way, when the OP ratio output does not change for a certain period of time, the so-called progressive wave Nu is detected, and when automatic inspection is performed normally, the OP is output at regular intervals as shown in time chart 1 in Figure 2. Since “1” and “0” are repeated, the time-limited operation circuit 20
doesn't work. Figure 6 shows a total failure detection circuit according to the present invention, where 10A is the output terminal of an undervoltage relay, 21.22 is an AND circuit, 23 is an 801 circuit, 24.25 is a 011 circuit, and 26 is a total failure detection circuit. This is a time-limited operation circuit. AND circuit 2 when the undervoltage relay 10A output is not output.
1 also outputs an output, so the AND circuit 22 also does not generate an output, and the time-limited operation circuit 26 is not activated, so it is in a state where a total stop has not been detected. At this time, an automatic inspection is performed and the undervoltage relay 10A operates to generate an output, and the AND
Even if the output of the circuit 21 is at the "1" level, the output of the NOT circuit 23 is at the "0" level at 7j when the inspection step S1 is producing an output, and since the total failure is not detected, the OR circuit 24 is No output is produced, and one end of the input of the AND circuit 22 is held at O level. Therefore, the time limit operation circuit 26 is not activated and complete stop detection is not performed. Next, if there is a complete power outage before the automatic inspection, the undervoltage relay 10A operates and outputs, so the output of the AND circuit 21 becomes "1".
level. Also, since the inspection step S1 does not produce an output, the output of the NOT circuit 23 is at the "1" level, and the output of the OR circuit 24 is at the "1" level, so the AN
The output of the D circuit 22 also goes to the "1" level, and the time-limited operation circuit 26 is activated to issue an alarm after the settling time. Once a full stop is detected, the output of the OR circuit 24 is controlled to the "1" level while the full stop is detected. If automatic inspection is performed in this state, undervoltage #I! Since the electric appliance 10A continues to output its output, the output of the NO circuit 21 is at the "1" level. Here, the output of the inspection step S1 is generated, and the NO101 circuit 2
Even if the output is at the "0" level, the output circuit 24 is controlled at the "1" level under the full stop detection condition (\), so the AND circuit 2
2 remains at the "1" level. Therefore, the time-limited operation circuit maintains the state in which the total power failure is detected. As described above, in the total failure detection circuit according to the present invention, even if an automatic inspection is performed, the state before the automatic inspection is maintained.

Now, to explain the time coordination between the time-limited operation circuit 26 of the total power failure detection circuit and the time-limited operation circuit 15 for constant monitoring failure detection shown in FIG. 4, when the protected system becomes a total failure, in FIG.
Since the undervoltage relay 10A generates an output and the output Y1 of the OR circuit 25 goes to the "1" level, the time-limited operation circuit 15 is activated in the constant monitoring circuit of FIG. 4 unless an inspection is being performed. After that, in FIG. 6, the time limit operation circuit 26 detects a complete stoppage, so the AND1 circuit 12 is operated by the NUT circuit 11 in FIG.
Since this is locked, activation of the time-limited operation circuit 15 is also locked. ] From the above, when there is a full stop, if the full stop is not detected before the constant monitoring failure is detected, the constant monitoring will become defective, so the time limit operation circuit 15 must be set longer than the time limit operation circuit 26.

Next, assuming that a reset failure of the undervoltage relay occurs during automatic inspection, 81 and ×1 hold in Figure 1, and if the OP output remains at the "1" level due to the reset failure, then In FIG. 5, a time-limit operation circuit 20 is activated to generate the ANDN0 circuit 1 output and detect an inspection failure. If the complete stop detection condition is satisfied in Fig. 1 at this time, AND
Since the N0 circuit output is generated and the step circuit 6 is controlled to proceed to the next step S2, it becomes impossible to detect a return failure. For this reason, the total failure detection circuit according to the present invention is configured not to detect a total failure through automatic inspection, so the above-mentioned problem does not occur. However, in the conventional total failure detection circuit, the total failure detection time was made longer than the inspection failure detection time to avoid the above problem, but as a result, if the inspection failure detection time becomes longer, the total failure detection time also increases. It's long too [
I had to pull it. Furthermore, as explained above, the detection time for constant monitoring failures had to be lengthened.

Although one embodiment of the present invention has been described above, it goes without saying that if there is a method other than this embodiment that does not affect the stoppage detection circuit by automatic inspection, it will give the same result as the main train.

FIG. 7 shows another embodiment according to the present invention. 10 in Figure 7
A, 21.23.25.26 is a circuit similar to 'ls, Figure 6. 27 is a NOT circuit, 28 and 29 are AND circuits, and 30 is a flip-flop circuit that responds as shown in the truth table of FIG. Here, to explain the operation of FIG. 7, when automatic inspection is not performed, the output j of the NOT circuit 23 is controlled to the level 11, so the output x 1 of the all-stop clock circuit 21 is set to 11. ” level, the output of the quiet circuit 28 becomes “1” level, and NO
Since the output of the first circuit 27 is at the rOJ level, the outputs of the two AND circuits are at the "O" level. Since the 300 Å force of this /j flip-flop becomes S terminal Ml and R terminal "0", the Q terminal becomes "1" level from the truth gate of FIG. 8, and the time limit operation circuit 26 determines that the money has stopped after the settling time. do. Also, when it is not completely stopped, Xl is at the "0" level, so the AN
The DN0 circuit 2 becomes “0” level, the ANDN0 circuit 2 becomes “1” level, and the S terminal of the flip-flop circuit 30 becomes “O”.
, the Q terminal becomes "O" level due to the R terminal "1", and it is not determined that there is a total stop.

When the next automatic inspection is performed, the output of the NOT circuit 23 is r
Since it is controlled to the OJ level, the outputs of the ANDN0 circuit 229 both become "0" level, and the flip-flop circuit 30
Both the S and R terminals become "0", and the output of the Q terminal maintains its previous value (marked with *), that is, the state before the automatic inspection.

[Effects of the Invention] As described above, according to the present invention, since the total failure detection circuit is not affected at all by automatic inspection, time coordination with the detection time of the defective inspection detection circuit and the constant monitoring circuit can be achieved. There is no need to consider it. Essentially, the total failure detection time should be coordinated with the time for removing system faults, and it is not desirable to set it to be unnecessarily long. In addition, with the conventional method, there are platforms where the detection time of the constant monitoring circuit cannot be longer than the operational point of view, and in this case, t
I had to give up on detecting poor inspection.

Furthermore, according to the present invention, it becomes possible to set the total stop detection time of all devices to the same setting, which reduces the complexity of maintenance.

[Brief explanation of the drawing]

Fig. 1 is a stepwise circuit diagram, Fig. 2 is a time chart of the stepwise circuit, Fig. 3 is an inspection manual power application circuit diagram, Fig. 4 is a constant monitoring circuit diagram, Fig. 5 is an inspection defect detection circuit diagram, FIG. 6 is a diagram of a full stop detection circuit according to the present invention, FIG. 7 is a diagram of another embodiment, and FIG. 8 is a truth table of a flip-flop. 1~4,8,12,14.17,18,21,22,2
8.29...AND circuit 5.13.19.24.25
・・・・・・・・・・・・OR circuit 6・・・・・・・・・
・Step circuit 7.11.16.23.27・・・・・・・・・・・・
NOT circuit 15.20.26,・・・・・・・・・・・・
......Time-limited operation circuit 30...[[Circuit (7317) Agent Patent attorney Kensuke Norichika (and 1 other person) Fig. 2 Fig. 3

Claims (1)

[Claims] A protective relay device equipped with an undervoltage relay that detects a drop in system voltage includes a first circuit that determines a total outage when the undervoltage relay operates for more than a predetermined time, and a check input to the undervoltage relay. a second circuit that derives a lock output from the first circuit when the first circuit is held in its mouth;
If the circuit has already been determined to be completely stopped, the lock output is not derived for the first circuit, and the lock output is not derived for the first circuit only when the first circuit has not been determined to be completely stopped. A protective relay device characterized by deriving an output.