JP2780269B2 - Transmission line monitoring device and monitoring system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus and a system configuration for monitoring the state of a power supply line such as a transmission line, and in particular, sends each monitoring apparatus to a central monitoring station. The present invention relates to a configuration for compensating for a time lag in the detected current detection information.

[Prior Art] In a power supply line such as a transmission line, an accident such as a ground fault or a short circuit between phases occurs even though a sufficient withstand voltage configuration is adopted, and a large current flows through the transmission line. Sometimes. Therefore, it is necessary to promptly detect the presence or absence of such an accident and to locate the accident site to deal with the accident. Conventionally, a configuration as shown in FIG. 3 has been used to monitor the state of the power supply line such as the transmission line.

Referring to FIG. 3, a conventional transmission line monitoring system is provided at each of a plurality of predetermined points of transmission line 1 and detects a current flowing through the transmission line at the point, and a predetermined number of sensors S. A monitoring device LSl that is provided for each sensor and receives transmission line current detection information from each sensor S, performs predetermined processing on the received current information, and sends processing information to a central monitoring station MS at a predetermined timing. LSn and processing information from the monitoring stations LSl to LSn to monitor the state of the transmission line 1, that is, to detect the occurrence of an accident such as a ground fault in the transmission line and to locate the point where the accident has occurred. And a central monitoring station MS.

Information transmission between each monitoring device and between each monitoring device and the central monitoring station MS is performed by an information transmission line 2 composed of an optical fiber or the like combined with an overhead ground line provided in the transmission line.
Is performed via

As each of the sensors S, an optical magnetic field sensor, an optical CT (current transformer), or the like, which is provided near the transmission line 1 and detects a magnetic field induced by a current flowing through the transmission line 1, thereby deriving transmission line current information. Used.

Each of the monitoring devices LSl to LSn has a configuration as shown in FIG. That is, referring to FIG. 4, monitoring device LS includes a signal processing unit 10 for receiving current detection information from a corresponding sensor and performing a predetermined process, and a signal processing unit LS.
It comprises a transmission terminal 11 for adding and transmitting the processing information from 10 and processing information from an adjacent device, and an oscillator 12 and a counter 13 for giving operation timing of the signal processing unit 10 and the transmission terminal 11.

The oscillator 12 generates a clock signal of a predetermined frequency and supplies the clock signal to the signal processing unit 10 and the transmission terminal 11 as a basic clock signal.

The counter 13 receives the clock signal from the oscillator 12, generates an activation signal every predetermined number of clocks, and supplies the activation signal to the signal processing unit 10 and the transmission terminal 11, respectively.

The signal processing unit 10 provides processing information applied to the sensor output to the transmission terminal 11 in response to the synchronization signal from the counter 13. Various methods are used for the processing of the signal processing unit 10. For example, a method of receiving transmission line current detection information from each sensor and detecting transmission line current value and current phase information for each sensor output has been adopted. At this time, the phase information of the transmission line current information is derived based on the clock signal from the oscillator 12, for example, the clock signal from the oscillator 12 is counted, and the count value when the synchronization signal from the counter 13 is given is transmitted. It can also be used as phase information of wire current. In this case, the counting operation of the clock signal
First, initialization is performed so as to synchronize with the zero cross point of the transmission line current, and the count value is reset every cycle of the transmission line current. The count value indicates the time from the zero crossing point of the transmission line current, and thus the phase can be detected. Alternatively, it is activated when an activation signal from the counter 13 is applied, and the oscillator is activated.
The clock signal from 12 may be used to perform a counting operation until the transmission line current information from the sensor crosses zero, and the counted value may be used as phase information of the transmission line current. The derivation of the current value information is performed by sampling and holding the sensor output. Further, a configuration is also used in which sensor outputs provided at adjacent points are compared to determine whether the polarities of the two sensor outputs match, and the determination result is derived.

The transmission terminal 11 receives the processing information from the signal processing unit 10, and starts the transmission operation in response to the synchronization signal from the counter 13. Therefore, the current detection information in the monitoring device LS is transmitted from the transmission terminal 11 once at predetermined time intervals. Information from each monitoring device LS is transmitted to a central monitoring station MS via a signal line (information transmission path) 2. At the central monitoring station MS, based on the transmitted transmission line current information from each monitoring device LS, the presence or absence of an accident on the transmission line and the location of the occurrence of the accident are performed. In the central monitoring station MS, when an accident occurs, the current values or current polarities of the sensor outputs at both ends sandwiching the accident occurrence point are different, and the current value or the current polarity changes point (or section). ), The location of the accident was identified.

[Problems to be Solved by the Invention] As described above, in the conventional transmission line monitoring system, the information processing timing and the information transmission timing are given by the oscillator and the counter independently provided for each monitoring device. The current information in each monitoring device is sent to the central monitoring station MS via one information transmission line 2 composed of, for example, an optical fiber. Further, each monitoring device transmits the transmission line current information at predetermined time intervals. Central monitoring station MS
Due to the difference in the distance between the monitoring device (LSl) provided near and the monitoring device (LSn) provided far away, there is a time lag for the current information to reach the central monitoring station MS. As a result, the current information from each of the monitoring devices LSl to LSn that has reached the central monitoring station MS is not all transmission line current information sampled at the same time, and only information including an information transmission time error is provided from each monitoring device. There was a problem of not being given. That is, for example, the monitoring device LSn
The transmission line current information sampled at time t1 is added to the transmission line current information sampled at time t2 by the monitoring device LSl and sent to the central monitoring station MS,
The transmission line current information in the monitoring device LSn is
The information becomes older than the transmission line current information in Sl, and there is a problem that transmission line current information at the same time may not be provided to the central monitoring station MS.

Normally, when an accident occurs in a transmission line, it is necessary to detect the location of the accident section and detect the occurrence of the accident using transmission line current information detected at the same time over the entire transmission line. That is, as described above,
In locating an accident section, phase distribution and current value distribution over the entire transmission line are detected based on current information at the same time, thereby locating the accident section. If the information is not provided, there is a problem that it becomes impossible to accurately locate the accident section.

Therefore, the present invention eliminates the above-mentioned problems in the conventional transmission line monitoring system and has a simple configuration, and accurately locates an accident section even if there is a time lag in information transmission from each monitoring device. To provide a transmission line monitoring system and a monitoring device therefor.

[Means for Solving the Problems] A transmission line monitoring device according to the present invention is provided corresponding to a device, performs a timekeeping operation, and includes a timekeeping device that generates time information based on the timekeeping operation, and time information. A device that receives a radio broadcast, a device that extracts time information included in the broadcast information received by the receiving device, and a device that corrects the timekeeping operation of the timekeeping device based on the time information extracted by the extracting device, And a device for adding the time information generated by the time keeping device to the transmission line current information detected by the device and sending it out.

Preferably, the receiving device is activated in response to a signal from the timing device only for a period of a predetermined time width with respect to the time at which the time information is to be given. Preferably, the operation timing of the device, that is, the timing operation in a clock signal generation circuit including, for example, a counter for providing a detection timing of a signal (transmission line current information) and an information transmission timing is based on time information extracted from the extraction device. Is corrected.

A transmission line monitoring system according to the present invention is configured by disposing the above-described transmission line monitoring device according to the present invention at a plurality of predetermined positions of a power supply line composed of a transmission line or the like.

[Operation] The monitoring device according to the present invention is provided with a timekeeping device that always generates accurate time information, and the time information from the timekeeping device is added to the transmission line current information to be transmitted to monitor the central time. Sent to the office. Therefore, the central monitoring station can determine whether the transmission line current information sent from each monitoring device is the transmission line current information detected at the same time, and Since the current information also includes time information, it is possible to form transmission line current information at the same time based on this time information, thereby enabling accurate localization of accident sections and accident points. Becomes

Further, if the extracted time information is used as a synchronization signal for synchronizing the operations of the monitoring devices, the synchronization operation of each monitoring device can be easily realized.

FIG. 1 is a diagram showing an example of the configuration of a transmission line monitoring system according to an embodiment of the present invention. Referring to FIG. 1, a current flowing through transmission line 1 is detected at each of predetermined points of transmission line 1 as in the prior art, and the detected transmission line current information is transmitted to a central monitoring station MS. Monitoring devices LSl to LSn are provided.

Each of the monitoring devices LSl to LSn is, for example, 1 to prevent a time lag of transmission line current detection information caused by a difference in distance between the central monitoring station MS and each of the monitoring devices LSl to LSn.
A receiving device 20 for receiving a wireless broadcast including time information (hour information) given for each time, an extracting device 21 for extracting the time information included in the broadcast information received by the receiving device 20, A clock function circuit 22 that generates time information in accordance with the timekeeping operation, and corrects (i.e., adjusts) the timekeeping operation in response to the time information extracted from the extraction device 21; A transmission terminal that adds and sends the time information from the functional circuit 22
11 '. Here, in FIG. 1, a sensor for detecting a transmission line current and a signal processing unit for performing predetermined signal processing on a signal from the sensor are omitted for simplification of the drawing. Receiving device 20
Is activated in response to a signal from the clock function circuit 22, and is activated only during a period of a predetermined time width with respect to a period in which time information included in the radio broadcast is given, to be in a receivable state.

Various configurations can be applied to the configuration of the extraction device 21. For example, if the radio broadcast received by the receiving device 20 is an NHK broadcast, a signal of a predetermined frequency is given three times at intervals of 1 second for 3 seconds prior to the hour information, and then a signal of a frequency one octave higher than the predetermined frequency is given. Time information is being sent. Therefore, the signal of this predetermined frequency is output at 3
If the configuration is such that a pulse is generated in response to a signal of a given frequency that is given next after being given once, a time information extracting circuit can be easily constituted.

The clock function circuit device 22 has a clock unit for performing a unique timekeeping operation therein, and time information derived from the clock unit is supplied to the transmission terminal 11 '. For example, as shown in FIG. 4, a counter circuit for counting a clock signal from a unique oscillator provided inside the apparatus is provided, and time information is generated in response to the output of the counter circuit. If the clock counter operation is corrected by the time information extracted from the extracting device 21, a clock function circuit that can always generate accurate time information can be realized. That is, the counter output indicating minutes and seconds is reset in response to the time information from the extracting device 21, and a pulse for a predetermined time is generated for the time information after both the minutes and seconds information indicate zero. Is generated, the time information is not corrected, and if the time information extracted before the pulse generation is given, the time information is advanced by one, so that the time, minute, and second can be easily corrected. A clock function circuit that can perform the clock function can be realized. The clock function circuit 22 generates a pulse for a predetermined time width (for example, from one minute before the time information is received) to the time when the time information should be included in the broadcast information to be received, and gives the pulse to the receiving device 20. By receiving device 20
Is in a receivable state only for the predetermined time width. As a result, power consumption in receiving device 20 can be reduced. Instead of generating the signal from the clock function circuit 22, the receiving device 20 may be provided with a timer function so that the power of the receiving device 20 is turned on a predetermined time before the time when the time information is given. At this time, in order to shut off the power of the receiving device 20, a configuration in which the power is turned off in response to the extraction time information from the extracting device 21 may be combined. Next, the operation will be briefly described. The clock function circuit 22 in each monitoring device generates time information by its own built-in clock function, and supplies it to the transmission terminal 11 '. The transfer terminal 11 ′ sends the time information from the clock function circuit 22 to the signal line 2 together with the current information flowing through the transmission line 1 at a predetermined time interval. When the clock function circuit 22 reaches the time at which the time information contained in the radio broadcast should be received, in accordance with the internal clocking operation, it generates a signal and gives it to the receiving device 20. The power of the receiving device 20 is turned on in response to the activation signal from the clock function circuit 22, and the receiving device 20 enters a receivable state. The time information included in the radio broadcast is extracted by the extraction device 21 and provided to the clock function circuit 22. The clock function circuit 22 corrects the clocking operation and the time information based on the time information extracted from the extraction circuit device 21. Therefore, the time information generated by the clock function circuit 22 is always accurate, and the time information derived by each of the monitoring devices LSl to LSn is the same, that is, synchronized time information. Each of these monitoring devices LSl to LSn
Is transmitted to the central monitoring station MS via the information transmission line 2. At the central monitoring station MS, each monitoring device LS
Transmission line current information and time information transmitted from l to LSn are detected, and it is detected at which time the detected information is transmitted from each monitoring device. Accordingly, even if there is a time difference in the transmission line current information transmitted by each of the monitoring devices LSl to LSn, the central monitoring station MS transmits the transmission at the same time based on the time information attached to each transmission line current. Wire current information can be reconstructed. That is, for example, at the central monitoring station MS, if the transmission line current information and the time information sent from each monitoring station are printed out or displayed, for example, when a person looks at each current information and the time information and transmits the transmission line current at the same time, The information can be easily rearranged, whereby the presence / absence of an accident in the transmission line and the location and location of the accident can be determined based on the transmission line current information at the same time.

In the above-described configuration, the transmission line current information and the detection time information are simply added and transmitted.However, at this time, the clock circuit that gives the information detection operation timing in each monitoring device is not synchronized. It is conceivable that a time difference occurs in the detection operation in the monitoring device.
In order to prevent such an error in the detection time in each monitoring device, for example, as shown in FIG.
In each of the above, if the configuration is such that the time information extracted by the extraction device 21 is provided to the counter 12 as a reset signal for the counter 12 that provides the operation timing of the signal processing unit 10 and the transmission terminal 11 ′, the counting operation in the counter 12 It is always synchronized with the time information, and it becomes possible to synchronize the start time of counting of the counter in each monitoring device, and it is possible to synchronize transmission line current information detection timing and transmission timing in each monitoring device in all monitoring devices. It becomes possible.

In the above embodiment, the current to be monitored by the monitoring device is a current flowing through a transmission line, but the monitoring device of the present invention can be applied to a power line such as an underground line instead.

[Effects of the Invention] As described above, according to the present invention, time information included in a radio broadcast is extracted, and the extracted time information is used as a synchronization signal to correct time information generated by a built-in clock function circuit. And the time information from the built-in clock function circuit is added to the transmission line current information and sent to the central monitoring station. The transmission line current information detection time can be ascertained, the transmission line current information at the same time can be constructed at the time of occurrence of an accident or the like, and the fault section and point can be accurately located.
Also, by using the extracted time information to synchronize transmission line current detection and information transmission timing in each device, the operation synchronization in each detection monitoring device can be performed without using a complicated circuit configuration. It can be easily realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the configuration of a transmission line monitoring system according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a specific configuration of a monitoring device according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of the configuration of a conventional transmission line monitoring system. FIG. 4 is a diagram schematically showing an example of the configuration of a conventional monitoring device. In the figure, 1 is a transmission line, 2 is an information transmission line, 10 is a signal processing unit, 11 and 11 'are transmission terminals, 12 is a counter, 13 is an oscillator, 20 is a receiving device, 21 is a time information extraction circuit, and 22 is A clock function circuit, LS, LSl to LSn are monitoring devices, and MS is a central monitoring station. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (6)

(57) [Claims] 1. Current information for receiving current detection information flowing through the power supply line from a sensor provided at each of predetermined points on the power supply line, and transmitting the received current detection information to a central monitoring station. A device for generating and sending the same to the central monitoring station, wherein the device is provided at a predetermined point on the power supply line so as to receive a plurality of sensor outputs, A means for generating time information by performing a timing operation, a means for receiving a radio broadcast including the time information, and a means for extracting time information from the broadcast information received by the receiving means. Means for correcting the timekeeping operation of the time information generating means in response to the time information extracted from the extracting means; and adding the time information from the time information generating means to the generated current information. And means for delivering Te, power line monitoring device. 2. The receiving means is activated in response to a signal from the time information generating means only during a period having a predetermined time width with respect to a time at which time information contained in the radio broadcast is to be given. The transmission line monitoring device according to claim 1. 3. The apparatus according to claim 1, further comprising a timing clock generating means for giving an operation timing of the apparatus, wherein the timing clock generating means responds to a time information extraction signal from the extracting means. The transmission line monitoring device according to claim 1 or 2, further comprising a means for correcting timing. 4. A current to be sent to a central monitoring station based on received current detection information flowing through the power supply line from sensors provided at each of a plurality of predetermined points on the power supply line. A transmission line monitoring system comprising a plurality of devices for generating information and transmitting the information to the central monitoring station, each of the plurality of devices being provided at a predetermined point of the power supply line, wherein the plurality of devices are provided. Each of which is configured to receive a plurality of sensor outputs, wherein each of the plurality of devices is provided in the device, and includes means for performing timekeeping operation to generate time information; and including time information. Means for receiving a radio broadcast; means for extracting time information contained therein from the broadcast information received by the receiving means; and responding to the extracted time information from the extracting means, Information source Means and includes a means for the time information from the time information generating means transmits in addition to the generated current information, transmission line monitoring system for correcting timing operations of. 5. The method according to claim 1, wherein said receiving means is activated only in a period having a predetermined time width with respect to a time at which time information of said radio broadcast is to be provided, in response to a signal from said time information generating means. The transmission line monitoring system according to claim 4. 6. Each of the plurality of devices has timing clock generating means for giving an operation timing of the device, and each of the devices responds to time information extracted from the extracting means. 6. The transmission line monitoring system according to claim 4, further comprising: means for correcting a clock generation timing of said timing clock generation means.