JPH0456533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improving reliability during inspection of a protective relay device.

[Background technology of the invention and its problems]

In recent years, many static relays have been used in protective relay devices to improve system detection sensitivity and speed up operation.

Since the number of electronic components that make up these static relays is extremely large, reliability is improved through automatic inspection and constant monitoring. Since it is not possible to stop the grid every time static relays are automatically inspected, they are normally inspected while connected to the grid. In the unlikely event that a system failure occurs during an inspection, the relay being inspected must be able to respond to the system failure after the influence of the simulated input for inspection has disappeared, and a shear command is issued at high speed. I can't. For faults that require particularly high-speed disconnection, such as internal faults in transformers, the delay may be unacceptable.

Figure 1 shows an example of a transformer protection device. In Figure 1, the transformer 1 to be protected introduces the grid current converted by current transformers 2-1 and 2-2 provided on both sides as input to differential relays 3-1 and 3-2. . The differential relays 3-1 and 3-2 operate when a short circuit or ground fault occurs in a transformer within the protected area.

On the other hand, the inspection control circuits 4-1 and 4-2 of the differential relays 3-1 and 3-2 transmit their outputs to the differential relays 3-1 and 3-2.
1, 3-2 and auxiliary relays 6-1, 6- through relay drivers 5-1, 5-2.
Drive 2. Next, in Fig. 2, the differential relay 3
Normally open contact 3- which is closed by the operation of -1 and 3-2
1a, 3-2a and the normally closed contacts 6-1b, 6-2b of the auxiliary relays 6-1, 6-2 operated by the output of the inspection control circuits 4-1, 4-2 are all connected in series, and the differential Relay outputs 3-1a and 3-2a close simultaneously, and there is no inspection control circuit output (normally closed contact 6-2a).
1b and 6-2b remain closed), a command is issued to the shear breaker. If you want to inspect the differential relay 3-1 now, open the normally closed contact 6-1b, disable the shrunken command circuit, and apply an inspection command to the differential relay 3-1 using the inspection control circuit 4-1. Operate 3-1.

Differential relay 3-1 If a failure occurs inside the transformer during inspection, differential relay 3 that has not been inspected
-2 can operate correctly, but the shearing command circuit is not established because the contact 6-1b is open. While inspecting differential relay 3-1, the other differential relay 3-
2 is activated, the inspection control circuit 4-1 is returned to its normal state, and the so-called accident response is generally carried out by activating the shear cutoff command circuit, but it is normally closed after the influence of the inspection simulation input disappears. Contact 6-1b
must be restored, and the issuing of the shearing command is inevitably delayed compared to the normal state where no inspection is performed. If an internal accident in a transformer causes a delay in issuing a shutdown command and removing the fault, serious problems may occur, such as a tank explosion. Differential relay 3
-1 As explained in the case during inspection, differential relay 3-
The same applies to the case where item 2 is being inspected.

As a measure to hasten the breakdown time, as shown in FIG. 3, a normally open contact 6- of an auxiliary relay 6-1 is connected in parallel with the output contact 3-1a of the differential relay 3-1 and is activated by the inspection control circuit 4-1. Connect 1a and connect differential relay 3
-2 can be connected in the same way, and each can be connected in series. According to this method, the normally open contact 6-
1a is closed, and the differential relay 3-2 can issue a shrunken command independently, so that it is possible to eliminate the failure during inspection without waiting for a delay in accident response time. However, if the normally open contacts 6-1a and 6-2a, which are closed by the inspection command, are closed at the same time for some reason even if the differential relays 3-1 and 3-2 do not operate in the break-off command circuit shown in Figure 3, A cessation order will be issued. In the shunting command circuit shown in Figure 3, if an internal failure occurs during inspection of one differential relay, the shunting command can be issued immediately using only the output of the other differential relay, and the command can be issued after waiting for time to respond to the accident. It is possible to disconnect at a higher speed than when issuing a disconnection command, but depending on the response of the contacts that close in response to the inspection command, the disconnection command may be issued even without the differential relay operating. This results in an extremely unreliable device.

[Purpose of the invention]

The present invention has been made in view of this point, and has a shatter disconnection command circuit configured such that when one protective relay is being inspected, a sheath disconnection command can be issued only by the response of the other relay, and the inspection disconnection command is issued at the same time. Highly reliable protection can be achieved by configuring an inspection circuit that does not output output to two protective relays, or a disconnection command circuit that outputs inspection commands to two protective relays at the same time and prevents a disconnection command from being output. The purpose of this invention is to provide a relay device.

[Summary of the invention]

The first invention has first and second protective relays that operate when a fault occurs within the target protection zone, and when both the first and second protective relays operate, the protection zone or disconnector is activated. A protective relay device that issues a disconnection command includes first and second inspection control circuits for providing inspection input to the first and second protective relays, and excitation by the outputs of the first and second inspection control circuits. and a first and second auxiliary relay, and when both the first and second protective relays are not being inspected, the first and second protective relays are inspected from the first and second inspection control circuits. an inspection circuit that is configured to be able to apply an input and that locks inspection of the other protective relay by the operation output of an auxiliary relay corresponding to the protective relay during inspection of one of the protective relays; The present invention provides a protective relay device characterized in that a shunt disconnection command circuit is provided in which the outputs of the first and second auxiliary relays are connected in parallel with the outputs of the second protective relay, respectively. Also, the second
The invention includes first and second protective relays, first and second inspection control circuits, first and second auxiliary relays, and an inspection input to one of the protective relays of the protective relay device of the first invention. The auxiliary relay energized by the auxiliary relay and the other protective relay are both activated, and the protective relay is deactivated and the first and second auxiliary relays are both activated. A protective relay device is provided which includes a shield disconnection command circuit that prevents a brake disconnection command.

[Embodiments of the invention]

An embodiment of the first invention will be described with reference to FIGS. 4 and 5. Figure 4 shows transformer 1 and current transformer 2 in Figure 1.
The input parts of -1, 2-2 and differential relays (hereinafter referred to as relays) 3-1, 3-2 are omitted, and the inspection control circuit necessary to explain the main parts of the present invention is extracted. It is a diagram. First inspection control circuit 4
-1 output indicates that the normally closed contact 6-2b of the auxiliary relay (hereinafter referred to as auxiliary relay) 6-2 operated by the output of the second inspection control circuit 4-2 is closed (auxiliary relay 6-2 is inoperable), the auxiliary relay 6-1 is connected via the relay driver 5-1.
to drive. In addition, since the inspection simulation input to the relay 3-1 is performed on the condition that the auxiliary relay 6-2b is inoperative, in response to the inspection control in the shingle disconnection command circuit shown in Fig. 5, either of the routes Neither holds true. The disconnection command condition is met in either route (when both relays operate), or in the normally open contact 6-1a or 6- of one of the auxiliary relays for inspection command.
2a and the output of a relay that is not under inspection control (responses only under system conditions), and even if inspection commands are issued at the same time by mistake, relays 3-1 and 3 Since the inspection simulation input is not simultaneously applied to -2 and one of the relays can always respond to the system conditions, an extremely reliable inspection control circuit can be obtained.

FIGS. 6 and 7 are diagrams for explaining other embodiments of the first invention. In FIG. 7, a coil 7-1 is connected in parallel with the normally open contact 3-1a of the first relay output and the normally open contact 6-1a operated by the inspection command. Normally open contact 3 of the second relay output
A coil 7-2 is similarly connected to -2a, and one end of these circuits operates in conjunction with the power supply P, and the other end with the limiting resistor 8 and the main contact of the breaker (not shown). It is connected to the power supply N via the auxiliary contact 9. Normal relay output contacts 3-1a, 3-2a
are both open, and contacts 6-1a and 6-2a, which operate in response to an inspection command, are also open. Furthermore, if the breaker is closed, the auxiliary contact 9 is also closed, so the coils 7-1 and 7-2 are excited by the power sources P and N and are always in operation.

Now, when attempting to inspect the first relay, in Fig. 6, the output of the inspection control circuit 4-1 is the normally open contact of the coil 7-2, which operates when the output contact of the second relay is open. This is possible on the condition that 7-2a is closed. First relay 3-1
Since the auxiliary relay 6-1 operates during the inspection, the contact 6-1a closes in Fig. 7, and the auxiliary relay 7
The coil 7-1 is de-energized and the contact 7 in FIG.
-1a is opened. The same applies when attempting to inspect the second relay.

Reliability can be further increased by validating the inspection control command after confirming that the contacts used in the shear disconnection command circuit shown in FIG. 7 are reliably open.

The circuits shown in FIGS. 4 and 5 and the circuits shown in FIGS. 6 and 7 may be used in combination. Further, an example of this combination is shown in FIG. 9 to make this content clear.

Next, a second embodiment of the invention will be described with reference to FIG. The inspection control circuit used in combination with FIG. 8 may be any one of FIG. 1, FIG. 4, or FIG. 6. In FIG. 8, there are four combinations that can constitute a shrunken command. The first route is a circuit consisting of the normally open contact 3-1a of the first relay, the normally closed contact 6-1b that opens during inspection control of the first relay, and the normally open contact 3-2a of the second relay. The shear cut command is issued by this circuit. The same is true for the route. The route is composed of a normally open contact 6-1a that is closed during inspection control of the first relay and a normally open contact 3-2a of the second relay. This is a circuit that immediately issues a smoldering command if the second relay, which responds to a failure in the system, operates during inspection of the first relay. The same is true for the route. According to the circuit shown in FIG. 8, the auxiliary relay 6-1 and the second relay operate according to the control command 4-1 of the first relay.
Even if the auxiliary relays 6-2, which are activated by the control command 4-2 of the relay, operate simultaneously for some reason, the circuit can be configured to prevent unnecessary unnecessary or disconnection commands from being issued in response to these two auxiliary relays. can. Note that the normally open contact 6-1a and the normally closed contact 6-1a
1b is configured so that it does not wrap when opening and closing. The same applies to 6-2a and 6-2b.

Although the above-described embodiments of the first and second inventions have been described using two sets of relays, the present invention is also applicable to a device using three or more sets of relays.

Further, although the example of the transformer protection device has been given, the object to be protected can also be applied to power transmission lines, busbars, etc., and is not particularly limited.

〔Effect of the invention〕

As explained above, according to the present invention, when inspecting one of the relays in a device having a plurality of relays operating within a protected area, there will be no delay in disconnection even if an accident occurs during inspection. It is possible to provide an extremely reliable control circuit even in a power-off command circuit.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an example of a conventional protection circuit, FIGS. 2 and 3 are circuits configuring the protection circuit, and FIGS. 4 and 5 each illustrate an embodiment of the present invention. FIG. 6 and FIG. 7 are a relay sequence diagram of an inspection command control circuit and an inspection circuit for explaining other embodiments of the present invention, respectively; FIG. 8 is a shear cutting command configuration circuit for explaining an embodiment of the second invention, and FIG. 9 is an inspection command control circuit diagram showing another embodiment of the first invention. 1...Protected object, 2...Current transformer, 3-1, 3-2...
Differential relay, 4-1, 4-2...Inspection control circuit, 6
-1, 6-2... Auxiliary relay operated by the inspection command, 7-1, 7-2... Coil for checking the shear disconnection command circuit.

Claims (1)

[Claims] 1. A protective relay that outputs a shear disconnection command to a target shear disconnector on the condition that both the first and second protective relays that operate due to the occurrence of a failure within the target protection zone are activated. In the electrical equipment, first and second inspection control circuits for providing inspection inputs to the first and second protective relays, and first and second inspection control circuits excited by the outputs of the first and second inspection control circuits are provided. While the second auxiliary relay and the first and second protective relays are not being inspected, inspection input can be applied from the first and second inspection control circuits to the first and second protective relays. and an inspection circuit configured to lock inspection of the other protective relay by the operating output of the auxiliary relay corresponding to the protective relay during inspection of either one of the protective relays, and outputs of the first and second protective relays. A protective relay device comprising: and a shunt-off command circuit connected in parallel with the outputs of the first and second auxiliary relays, respectively. 2. In a protective relay device that outputs a cut-off command to a target cut-off switch on the condition that both the first and second protective relays that operate due to the occurrence of a fault within the target protection zone have operated, first and second inspection control circuits for giving inspection inputs to the first and second protective relays; The auxiliary relay and the auxiliary relay energized by the inspection input to one protective relay and the other protective relay are both activated. 1. A protective relay device comprising: a shear disconnection command circuit that prevents a shear disconnection command under the condition that both auxiliary relays have operated.