JP2607307B2 - Fault detection system for distribution lines - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an accident section detection system for locating an accident section of a distribution line and a protection device therefor.

[Prior Art] With respect to a power transmission system, an accident section detection method of monitoring a current / voltage of a transmission line and locating an accident section of a distribution line is adopted. Similarly to the transmission system, it is conceivable to adopt an accident section detection method for monitoring the current or voltage of the distribution line and locating the accident section of the distribution line.

In this method, switches may be provided separately along the distribution line, and a protection device for detecting an accident may be arranged for each switch. When each protection device detects an accident, it opens the corresponding switch to cut off the power supply.

In detecting such an accident, it is preferable to operate the switch closest to the accident point on the upstream side of the accident point in order to minimize the power failure range. Therefore, it is necessary to be able to confirm the state of another protection device adjacent to each protection device via a communication line. In this case, it is assumed that the communication system is normal.

In such a case, it is common to monitor the malfunction of the communication line and stop the operation of the device if the communication line is malfunctioning in order to avoid malfunction. For this reason, in the detection of an accident of the distribution line, it is necessary to confirm whether the communication state with the adjacent protection device adjacent, particularly on the downstream side, is normal.

[Problems to be Solved by the Invention] However, in an accident section detection device that is distributed and installed on a distribution line and locates an accident section, the operation power of the device is supplied from a distribution system, so that a stable operation power supply is secured. Have difficulty. That is, when an accident occurs, power may not be supplied to the downstream side. In particular, when an accident is detected and the switch on the upstream side of the accident point is opened, power is not supplied to the downstream side. For this reason, the device cannot operate, and signal transmission cannot be performed despite good communication lines. Even in this case, it is necessary to know the state of the other protection device, so that there is a problem that the protection device on the upstream side cannot operate. However, depending on the situation of the distribution line accident, it may be necessary to detect the accident section.

On the other hand, for example, in the detection of an accident in a transmission line or the like, the duplexing of communication lines “preparing another communication line (including microwaves or the like)” is performed in consideration of the occurrence of the failure of the communication line. We are dealing with this.

However, the duplication of communication lines in distribution line protection involves wiring on the same pole,
There is a risk of becoming normal, and it cannot be expected to be so effective.
Moreover, even if the communication line is duplicated, communication is impossible if power is not supplied to the protection device.

Here, the concept of detecting an accident section in a distribution line using the distribution system shown in FIG. 3 will be described.

The distribution system in FIG. 3 is a distribution line L from the distribution substation SS.
, A pole switch CB is sequentially connected. Further, in this distribution system, protection devices 1, 2, and 3 are provided corresponding to each pole switch CB. A communication device 10 is built in each of the protection devices 1, 2, and 3. These communication devices 10 are sequentially connected with communication lines TL1 to TL4.

If an accident occurs at point F1 in such a configuration,
After the protection device 2 operates the relay and detects this accident, performs mutual transmission with the protection device 3 via the communication line TL3, and confirms that the accident section is between the protection device 2 and the protection device 3. Open the switchgear CB2 and eliminate the accident section.

At the time of this mutual confirmation, the switch CB2 is opened under the condition that the carrier detection signal for detecting the failure of the communication line TL3 is valid (the communication line is normal).

 The above accident detection is referred to as first accident detection.

Here, for example, it is assumed that the accident at the point F1 is a short circuit accident and a permanent accident.

The switch CB2 opened earlier (when the first accident was detected) was
Reapply after a certain period of time, and perform test power transmission. Then, immediately after the insertion, when the protection device 2 detects an accident,
It is necessary to determine a permanent accident between the protection device 2 and the protection device 3 and open the switch CB2 again.

 This accident at the time of test transmission is referred to as a second accident.

At the time of the test power transmission, the protection device 3 cannot perform the mutual information transmission since the operation power supply is not established. At this time,
The carrier detection signal for detecting a failure of the communication line of the protection device 2 is invalid. That is, at the time of the first accident judgment, the condition of the accident judgment is that the carrier signal is valid, and at the time of the second accident judgment, even if the carrier signal is invalid, the protection device 2 needs to judge the accident.

In addition, although not shown, during the temporary loop operation of the power distribution system, a power flow more than the set tap of the protection relay may flow. In this case, it is necessary to prohibit opening of the switch CB due to accident detection. At this time, it is necessary that all communication lines are normal.

As can be understood from the above description, in the detection of an accident in the distribution system, there is a contradiction that once an accident occurs, the state of the adjacent protection device on the downstream side cannot be confirmed. This point is an important problem to be solved when realizing fault section detection in the distribution system.

It is conceivable that each protection device is backed up by a battery. However, in a distribution system in which a large number of protection devices are installed on a utility pole and distributed in a large number, maintenance and inspection take time and are not practical.

The present invention has been made to solve such a contradiction, and an object thereof is to reliably detect a second accident even if a carrier signal of a communication line is invalid after the first accident. It is an object of the present invention to provide an accident section detection method capable of performing highly reliable distribution line accident section location.

[Means for Solving the Problems] To achieve the above object, according to one embodiment of the present invention, there are provided a plurality of switches, and a switch provided for each of the switches, which detects an accident section and corresponds thereto. A plurality of protection devices to be opened and closed, distributed along the distribution line, and each of the protection devices is provided with a communication system communicably connected between adjacent protection devices along the distribution line; Means for transmitting a signal indicating that the communication function of the own device is operating normally to the adjacent other device via the communication system; and Means for receiving a signal indicating that the communication function of the other device is operating normally, means for transmitting an accident detection signal detected by the own device to an adjacent other device via the communication system, Other devices Means for receiving an accident detection signal transmitted from the communication system via the communication system, and a signal indicating that the communication function is operating normally based on the signal received via the communication system. Means for detecting whether or not the communication function is operating normally; self-side accident detection means for detecting an accident in the distribution line in the own device; and accident detection by the self-end accident detection means, and accident detection In the case where the signal receiving means receives an accident detection signal from an adjacent other device, and when it is detected that the communication function of the other device is normal, an accident section in which an accident occurrence section is determined. Determining means, when the accident section determining means determines that the accident section is between the switch corresponding to the own device and the adjacent switch on the downstream side, opens the switch of the own device. Indicate Means for instructing the switch that has been opened in response to the above opening instruction to reconnect for test power transmission, and within a certain period of time after the switch is reconnected, the self-end accident detection means Is detected, regardless of the presence or absence of a signal from the other device, the detected accident is determined to be a permanent accident occurring between the other device and the own device, and the switch is opened to the switch. Means for instructing a distribution line fault.

The means for detecting whether or not the communication function of the adjacent other device is operating normally detects whether or not the communication function is operating normally, for example, by detecting the presence or absence of a carrier signal used for information communication. Configuration.

[Operation] At the time of the first accident detection described above, that is, at the time of judging an accident that occurs when each device has a normal operating power supply, the second accident is performed on the condition that the carrier signal is valid. At the time of detection, a carrier signal is ignored, and an accident is determined only by own-end information. As a result, even if another adjacent protection device is out of power and the communication system is normal, it is possible to cope with an accident with only the own device and improve the reliability of accident detection.

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

FIG. 1 shows a configuration of an embodiment of an accident section detection system according to the present invention.

This embodiment is similar to the one shown in FIG.
The present invention is applied to a distribution system in which a switch CB is sequentially connected to a distribution line L from an SS.

As shown in FIG. 1 (a), the system of this embodiment
It is provided with protection devices 11, 12, and 13 connected to each of the switches CB, and a communication line TL that sequentially connects these protection devices 11, 12, and 13.

The protection devices 11, 12, and 13 have the same configuration. FIG. 1 (b) shows an example.

In the figure, a protection device 11 includes a self-end accident detection circuit 400 for detecting an accident in its own device, an accident judgment circuit 200 for judging an accident section, a communication device 300, and a switch for opening and closing the switch. An open / close operation unit 500 is provided.

The accident determination circuit 200 is configured, for example, as shown in FIG.

In FIG. 2A, an accident determination circuit 200 monitors an information receiving circuit 201 that receives information from an adjacent protection device and outputs a received information signal RD, and a carrier of a communication line TL.
Carrier detection circuit 202 that outputs carrier detection signal CD
And an AND circuit 203 for calculating the logical product of the reception information signal RD and the carrier detection signal CD.

Further, the accident determination circuit 200 includes a timer 204 started by turning on the self-end switch CB or turning on the power, and a timer
Inverter 205 that inverts the output of 04 and operation inhibit signal E
, An AND circuit 207 that calculates the logical product of the operation inhibition signal E and the output of the inverter 205, a pseudo operation signal output circuit 208 that outputs a pseudo operation signal RDN, and a timer 204. An AND circuit 209 which takes the logical product of the output and the pseudo operation signal RDN;
An OR circuit 210 for calculating the logical sum of the outputs of 209, an inverter 211 for inverting the output signal of the carrier detection circuit 202, an AND circuit 212 for the output of the inverter 211 and the output of the OR circuit 210, and the AND circuit 203 , 212 OR circuit 213
And

The accident determination circuit 200 is the output of the self-end accident detection circuit 400 as shown in FIG. RyOUT,
An AND circuit 214 is provided for obtaining a logical sum of an output from the OR circuit 213 and outputting an open command. This part may be provided in the switch operation unit 500.

The accident determination circuit 200 uses these elements to detect whether or not the communication system with another adjacent protection device is operating normally, and to determine whether the communication system is normal when the first accident is detected. The accident section is determined on the condition that there is a fault, and when the second accident is detected, if the communication system is not normal, this is ignored and the accident section is determined based on the accident detection by the own device. Functions as determination means.

Further, the accident determination circuit 200 is a means for generating a pseudo operation signal indicating that an accident has occurred between the adjacent protection device and the own device, and after detecting the first accident, the switch is turned on again. Means for supplying the pseudo operation signal to the accident section determination means as an operation signal from another protection device for a certain time from the time when the communication is performed, and after the lapse of the certain time, the communication system operates normally. If the operation is not detected, it also functions as means for prohibiting accident detection.

The communication device 300 is configured, for example, as shown in FIG.

In FIG. 2B, the communication device 300 includes a modem 301.
And an interface 302 with the communication line TL.
The modulator / demodulator 301 transmits a transmission signal SD for transmitting a fault detection at its own end.
Modulates and transmits the carrier, receives and demodulates the accident detection signal from the other end, obtains the received signal RD, and
Detect carrier propagated to TL.

The communication device 300 and the communication line TL form a communication system.

The switchgear opening / closing operation section 500 is based on the opening command,
In addition to performing an operation of opening the switch, the switch also performs opening and closing operations based on a command from a higher-level device and a closing command.

Here, regarding the operation of the present embodiment,
The description will be given also with reference to FIGS. 2 (c) and 2 (d). FIG. 2 (c) functionally represents the circuit configuration of FIG. 2 (a).

CD is a carrier detection signal. When this signal is "1", it indicates that the communication line is valid (normal), and when it is "0", it indicates that the communication line is defective.

RD is a received information signal from the partner device. When this signal is "1", it indicates that the other party has no accident in the direction of its own end.

RDN is a pseudo operation signal, and E is an operation inhibition signal. RDN and E are signals generated on the own end side.

The timer T drives the switch SW1 for a fixed time determined from the time when the self-end switch is turned on or the time when power is turned on on the upstream side. Here, the switch SW1 indicates a logical function realized by the inverter 205, the AND circuits 207 and 209, and the OR circuit 210 shown in FIG. 2A.

The switches SWa and SWb are driven by the carrier detection signal CD, and select the output of the reception information signal RD when CD is “1”.
When CD is "0", it operates to select the signal from the switch SW1. Here, the switches SWa and SWb indicate functions realized by the AND circuit 203, the inverter 211, the AND circuit 212, and the OR circuit 213.

RD1, as shown in FIG. 2 (d), detects the self-end accident (R
yOUT) This is an operation signal used as an open command signal for opening the switch CB, based on the AND condition with the result.

Next, the operation of the accident zone detection system according to the present embodiment will be described with reference to FIG.

In the distribution system shown in FIG. 4, a time-sequential switching device DM is provided between the protection device 1 and the protection device 2. As described above, in the power distribution system provided with the timed sequential switching device DM, the response of the carrier signal at the time of the detection of the second accident becomes clearer.

First, it is assumed that an accident occurs at the point F11. In this case, the protection device 12 and the protection device 13 perform the first accident detection. First
The communication line is valid (CD = "1") and the protection device 3
(RD = “1”) and the condition of the relay operation of the protection device 2, the fault section (in this example, the fault section is between the protection device 2 and the protection device 3) is determined. You.
The protection device 12 performs such first accident detection (accident processing).
To open the switch CB2. Thereafter, after a certain period of time, the protection device 12 turns on the switch CB2 for test power transmission, and starts the timer T for the second accident determination.

Here, the call to the protection device 13 is performed by the timed sequential start device DM.
(Normally after 5 to 7 seconds), the carrier signal is turned on despite the fact that the protection device 12 turns on the switch CB2 and immediately detects the accident at point F11. As a result, this accident point cannot be eliminated, and inconvenience arises. Therefore, even in the situation where the carrier signal does not reach, the protection device 12 performs communication during the activation of the second accident detection determination timer T because the previously determined accident section is the section to be protected by the protection device 2. It is necessary to open the switch CB2 and eliminate the accident section under the condition of the line failure and the relay operation of the protection device 12.

The present embodiment deals with such a request for device response as follows.

(1) When the carrier detection signal CD is valid, the switch SWa is turned on, and the other end information RD is used unconditionally.

(Make unnecessary CB release time as short as possible.) (2) Activate timer T after turning on the self-end switch. Here, when there is no carrier signal CD, the switch SWb is turned on,
The pseudo operation signal RDN is derived to perform the second accident detection.

(3) When there is no carrier signal after a lapse of a predetermined time, the timer T is stopped, and the switch SW1 switches to the side for selecting the operation inhibition signal E. Further, since the carrier detection signal CD is not detected, the switch SWb is turned on, and the accident detection function of the protection device is prohibited. That is, the release command is not output.

(In order to avoid unnecessary operation during loop operation) In the above embodiment, the accident determination circuit is configured by hardware logic.
The configuration may be realized by a computer and software.

[Effects of the Invention] As described above, according to the present invention, it is possible to solve the inconsistency at the time of detection of a distribution line accident and to reliably detect a distribution line accident section even if the downstream protection device is out of power. , A highly reliable system can be constructed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an accident section detection system according to the present invention. FIG. 2 (a) is a block diagram showing an example of the configuration of an accident determination circuit used in the above embodiment. FIG. 2B is a block diagram showing an example of the configuration of a communication device used in the embodiment, FIG. 2C is an explanatory diagram functionally expressing the circuit configuration of FIG. 2A, and FIG. (D) is an explanatory diagram showing a relationship between an operation signal and a self-end fault detection result, FIG. 3 is an explanatory diagram for explaining a fault point of a distribution line and a switch opening point at the time of a fault, and FIG. 4 is a present embodiment. It is an explanatory view for explaining an accident point of a distribution line and a switch opening point at the time of an accident. 1,2,3,11,12,13… Protective device, 10,300… Communication device, 200
…… Accident judgment circuit, SS …… Distribution substation, L …… Distribution line,
CB: Switch, TL: Communication line, F1, F11: Accident point.

Claims (2)

(57) [Claims] 1. A plurality of switches and a plurality of protection devices provided for each of the switches, which detect an accident section and open / close the corresponding switches, are distributed and arranged along a distribution line. Each protection device is provided with a communication system that is communicably connected between adjacent protection devices along the distribution line, and each of the protection devices transmits a signal indicating that the communication function of its own device is operating normally to the adjacent protection device. Means for transmitting to the other device through the communication system, and receiving a signal transmitted from the adjacent other device via the communication system and indicating that the communication function of the other device is operating normally. Means, means for transmitting an accident detection signal detected by the own apparatus to an adjacent other apparatus via the communication system, and means for receiving an accident detection signal transmitted from the adjacent other apparatus via the communication system Means for detecting whether or not the communication function of an adjacent other device is operating normally based on a signal received via the communication system and indicating that the communication function is operating normally; Self-end accident detection means for detecting an accident in the electric wire in its own device, and an accident detected by the self-end accident detection means, and the means for receiving an accident detection signal received an accident detection signal from another adjacent device. In the case, when it is detected that the communication function of the other device is normal, the accident section determining means for determining the section in which the accident has occurred, and the accident section determining means corresponds to the own section corresponding to the accident section. Means for instructing the switch of its own device to open when it is determined that the switch is between the switch to be operated and the adjacent switch on the downstream side thereof; Of the trial transmission If the self-end accident detection means detects an accident within a certain period of time after the switch is turned on again, regardless of the presence or absence of signals from other devices, the detected Means for determining a permanent accident that has occurred between the other device and the own device, and instructing the switch to open the switch. 2. A protection device for a power distribution system, which is provided along a distribution line and is connected to each other via a communication system and, when an accident is detected, opens and closes a corresponding switch. Means for transmitting a signal indicating that the function is operating normally to an adjacent other device via the communication system, and a communication function of the other device transmitted from the adjacent other device via the communication system Means for receiving a signal indicating that the device is operating normally, means for transmitting an accident detection signal detected by its own device to an adjacent other device via the communication system, and Means for receiving an accident detection signal transmitted through the communication system, based on a signal received via the communication system indicating that the communication function is operating normally, Means for detecting whether the communication function is operating normally, self-end accident detection means for detecting an accident in the distribution line at its own device, and accident detection by the self-end accident detection means, and accident detection In the case where the signal receiving means receives an accident detection signal from an adjacent other device, and when it is detected that the communication function of the other device is normal, an accident section in which an accident occurrence section is determined. Determining means, when the accident section determining means determines that the accident section is between the switch corresponding to the own device and the adjacent switch on the downstream side, opens the switch of the own device. A means for instructing, a means for instructing the switch opened in response to the opening instruction to be turned on again for test power transmission, and a self-end accident detecting means within a fixed time after the switch is turned on again. If an accident is detected, Irrespective of the presence or absence of these signals, a means for determining that the detected accident is a permanent accident occurring between the other device and the own device and instructing the switch to open. A protection device for a distribution system, characterized in that: