JPH0636648B2 - Protective relay - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective relay device that outputs a disconnection command as needed when an accident in a power system is detected.

[Conventional technology]

FIG. 2 is, for example, a circuit configuration diagram showing an example of countermeasures against extinction of the polarity voltage memory at the time of the near end short-circuit accident of the conventional distance relay device shown in the magazine Denki Kyodo Kenkyu, Vol. 1a is an output contact which is closed by the operation of the overcurrent element 51, 2 is an output contact which is closed by the operation of the Moh characteristic distance direction determination element 44M, and 3 is an reactance characteristic distance direction determination element 44X _1. The output contacts 4 and 5 which are closed by the operation are ANDed with the outputs of the overcurrent element 51 and the two types of distance direction determination elements 44M and 44X _1.
The self-holding circuit 4 and the cutoff command output circuits 5 and 41 which operate when the configured output contacts 1a, 2 and 3 are closed are relays, and T5 is a timer.

Next, the operation will be described. First, when an accident occurs in the power system, the overcurrent element 51 operates and the output contact 1a is closed. If the accident occurs inside the protection section of the distance continuation device, two types of distance direction determination elements 44M, 44X ₁
Is operated and the respective output contacts 2 and 3 are closed. The above-mentioned overcurrent element 51, two types of distance direction determination elements 44M, 44X ₁
By closing each of the output contacts 1a, 2 and 3, the relay 41 operates to form the self-holding circuit 4 that bypasses the output contact 2 of the Moh characteristic distance direction determination element 44M. At the same time, the timer T5 operates and the cutoff command output circuit 5
Is activated, a shutoff command accompanied by an instantaneous action or a timed action is output, and the protection section is shut off.

By the way, since the Maw characteristic distance direction determination element 44M uses the voltage of the power system for the polarity voltage, the proximity to the inside of the protection section of the distance relay device where the voltage of the power system is zero or becomes very small. Since it cannot operate against an edge accident, it has a polarity voltage memory circuit and is generally configured to operate even if the polarity voltage is zero or very small. In the case of timed interruption with timed operation, the polarity voltage memory circuit disappears if an accident occurs in which the voltage of the power system becomes zero or becomes very small before the timed operation of timer T5 is completed. The mood characteristic distance direction determination element 44M is restored and the output contact 2 is opened,
Since the output contact 2 is bypassed by the self-holding circuit 4, the timed operation is continued and the cutoff command is output.

[Problems to be solved by the invention]

Since the conventional protective relay device is configured as described above, when the instrument transformer (line PD) is used, the overcurrent element and the distance direction determination are performed before the reclosing after the first interruption. The element, self-holding circuit, and shutoff command output circuit are restored. In this state, if an accident such as a short circuit remains at the nearest end inside the protection section of the distance relay device, the polarity voltage memory circuit of the Mo characteristic distance direction determination element has already disappeared,
Since the moo characteristic distance / direction determination element does not operate, there is a problem that re-interruption cannot be performed.

The present invention has been made in order to solve the above-mentioned problems, and also shuts off against a near-end accident in which the mood characteristic distance direction determination element becomes inoperable after reclosing the protection section of the distance relay. The purpose is to obtain a protective relay device that can output a command.

[Means for solving problems]

The protective relay device according to the present invention, when the near-end accident is detected by the near-end accident detection element, and the accident detection signal is output from the output circuit, the protection section is changed from the power system. This is to output a re-cutoff command to cut off.

[Operation] The accident detection element in the present invention is configured by an overcurrent element or the like, and detects that an accident has occurred in the power system. The accident detection signal output circuit (normally open contact of the timer T1) maintains the operating state of the relay device before reclosing by continuing the cutoff command by the distance direction determining element or the like for more than the reclosing time. The near-end accident detection element is composed of an undervoltage element, etc., and since the voltage of the power system such as the mood characteristic distance direction judgment element is used for the polarity voltage, it may become inoperative at the near-end accident. The inoperative range of the various elements. The reclosing signal reception circuit receives the reclosing command from the reclosing device, and detects that the reclosing has been performed by providing a time delay so that the reclosing command can operate reliably even in a short time. To do.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In the figure, the same parts as those in FIG. 2 are shown with the same reference numerals, and in FIG. 1, 1b is an output contact which is closed by the operation of the accident detection element 51B. The output contact closed by the same overcurrent element 51 as the contact 1a, T1 is a timer, and 6 is constituted by the normally open contact T1a of the timer T1.
Similar to T5, it operates by closing the output contacts 1a, 2 and 3 and outputs an accident detection signal for a reclosing time or longer, and 7 is a mood characteristic distance direction determination element 44.
An output contact that is closed by the operation of the near-end accident detection element 27 that detects a near-end accident inside the protection section where M is inoperative. In this example, the output contact is closed by an undervoltage element, T2 is a timer having a normally open contact T2a. 8 receives the reclosing condition 52C from the reclosing device,
In addition, a reclosing signal receiving circuit T3 having a timed return by a timer T2 so as to be able to re-close after reclosing, T3 has a normally open contact T3a. 9 is the accident detection element 5
1B, the near end accident detection element 27, the accident detection signal output circuit 6, and the reclosing signal receiving circuit 8 are AND-configured, and the output contacts 1b, T1b, 7, and T2a are closed to output a re-shutdown command output. Circuit.

Next, the operation will be described. First, when an accident occurs in the electric power system, first, the overcurrent element 51 operates and the output contact 1
a and 1b are closed. If the accident has occurred inside the protection section of the distance relay device, two types of distance direction determination elements 44
M, 44X ₁ operates, and output contacts 2 and 3 are closed. The overcurrent element 51, the distance direction determination elements 44M, 44X ₁
By closing each of the output contacts 1a, 2, 3 of the above, a self-holding circuit 4 for bypassing the output contact 2 of the Moh characteristic distance direction determination element 44M is formed and at the same time the timer T
5 operates, the shutoff command output circuit 5 is closed, a shutoff command is output, and the first shutoff of the protection section of the distance relay device is performed. Then, during the no-voltage time until the reclosing device performs the reclosing operation, when the line PD is used, the voltage of the power system is not applied to the distance relay device. The voltage memory circuit disappears. Further, since the protection section is cut off, the overcurrent element 5
1, the reactance distance direction determination element 44X ₁ returns. After the reclosing, if the accident remains at the nearest end inside the protection section, the overcurrent element 51 and the reactance characteristic distance direction judging element 44X ₁ are activated and the output contacts 1a, 1b, 3 are closed again. The characteristic distance direction determination element 44M is inoperative because the polarity voltage is zero or very small due to the near end accident and the polarity voltage memory circuit has disappeared, and the output contact 2 remains open. Since the output contact 2 is open, the self-holding circuit 4 and the shutoff command output circuit 5 do not operate, but the accident detection signal output circuit 6 is operating during the first shutoff, so the normally open contact is closed. Up to.
Further, upon receiving the reclosing condition 52C from the reclosing device, the reclosing signal receiving circuit 8 operates and its normally open contact T
2a closes. At this time, if the failure remains at the close end, the close end detection element 27 operates and the output contact 7 is closed. That is, the output contacts 1b and 7 of the accident detection element 51B, that is, the overcurrent element 51 and the near end accident detection element 27 are closed, and the accident detection signal output circuit 6 and the normally open contact T2a of the timer T2 are operated. Therefore, the timer T3 operates and the re-cutoff command output circuit 9 operates to output a cutoff command to recut the protection section.

In the above embodiment, the output contact 1 is connected to the accident detection element 51B.
Although b is shown, it may be shared with the output contact 1a of the overcurrent element 51.

Although the output contact 1b of the accident detection element 51B is provided with the overcurrent element 51, the voltage and current of the electric power system are used as the input amount, and the polarity voltage memory like the Maw characteristic distance direction determination element 44M is used. An element that can detect an accident without requiring such a memory effect may be provided.

Further, although the output contact 1b of the accident detection element 51B and the output contact 7 of the near end accident detection element 27 are shown separately, the output contact 1b of the accident detection element 51B and the near end accident detection element 27 are shown. The output contact 7 and the output contact 7 may be provided as the output contact 7 of one near-end accident detection element 27.

Further, the cutoff command output circuit 5 and the recutoff command output circuit 9 are separately provided, but the logical sum of the operation command to the cutoff command output circuit 5 and the operation command to the recutoff command output circuit 9 is shown. The collected matter may be applied to the cutoff command output circuit 5, and the cutoff command output circuit 5 and the recutoff command output circuit 9 may be provided as one unit.

〔The invention's effect〕

As described above, according to the present invention, when the near-end accident is detected by the near-end accident detection element and the accident detection signal is output from the accident detection signal output circuit, the protection section is changed from the power system. Since it is configured to output a re-cutoff command to cut off, even if a near-end accident occurs in which the mood characteristic distance direction determination element becomes inoperable after reclosing the protection section, the protection section can be cut off from the power system, etc. Has the effect of.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a protective relay device according to an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram of a conventional protective relay device. In the figure, the overcurrent element 51, 51B accident detection element 44M is motor characteristic distance direction determination element 44X ₁ reactance characteristic distance direction determination element, cutoff command output circuit 5, the fault detection signal output circuit 6, 27 Is a near-end accident detection element, 8 is a reclosing signal receiving circuit, and 9 is a re-closing command output circuit.

Claims (1)

[Claims] 1. A mood characteristic distance direction determination element for detecting an accident in a protection section of a power system, and shuts down the protection section from the power system for a predetermined time when an accident is detected by the mood characteristic distance direction determination element. In a protective relay device including a cutoff command output circuit that outputs a cutoff command, an accident is detected by a near end accident detection element that detects a near end accident inside the protection section and the mood characteristic distance direction determination element. In the case of being detected, an accident detection signal output circuit that outputs an accident detection signal indicating that an accident has been detected for a longer time than the predetermined time, and a near end accident is detected by the near end accident detection element, and When an accident detection signal is output from the accident detection signal output circuit, a re-shutoff command output circuit that outputs a re-shutoff command that shuts off the protection section from the power system is provided. That protective relay device.