JP3689078B2 - Fault location system and slave station used for fault location system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a failure point locating system for locating a failure point at the time of a ground fault in a transmission / distribution line, and in particular, a slave station that performs monitoring and detection of a zero-phase current and a zero-phase voltage in the transmission / distribution line, The present invention relates to a system including a master station that receives data based on a detection result and locates a failure point.
[0002]
[Prior art]
The conventional fault location system has a plurality of slave stations that detect either surge current or surge voltage generated in the event of a ground fault in the transmission and distribution line, and is synchronized by the GPS (Global Positioning System) time signal. The surge signal arrival time (hereinafter referred to as “surge arrival time”) is identified at each slave station that has been taken, and the location of the failure point is determined based on the difference in surge arrival times collected by the master station from each slave station. (For example, Patent Document 1).
[0003]
[Patent Document 1]
JP 2000-258487 A (pages 5 to 7, FIGS. 1 to 3)
[0004]
In this case, since the positioning accuracy of the fault location depends on the accuracy of the surge arrival time specified at each slave station, there are various methods for accurately specifying the surge arrival time at each slave station. It is used.
For example, in the failure point locating system of Patent Document 1, a surge authorization level that is set in advance higher than a noise level, and a reference level for determining a surge waveform start point. A surge waveform start level that is set lower than the surge approval level is set, and a past voltage or current waveform that goes back a certain time from the current time is stored and constantly updated. In specifying the surge arrival time, when the voltage or current exceeds the surge recognition level, the time when the surge waveform start level is first exceeded by going back the stored waveform is set as the surge arrival time.
That is, by appropriately setting the surge authorization level and the surge waveform start level, false detection due to noise is reduced and the accuracy of surge arrival time is expected.
[0005]
[Problems to be solved by the invention]
However, the waveform detected at each slave station differs depending on various conditions such as the distance from the failure point, the difference between the power supply side and the load side at the failure point, the ground fault, or the ground fault resistance. Therefore, it is difficult to appropriately detect the occurrence of a surge and specify the surge arrival time from waveform data of only one of voltage and current, and any of the waveforms in the fault location system of Patent Document 1 is also difficult. It is not always easy to appropriately set the surge approval level and the surge waveform start level for data. In addition, since each slave station is equipped with means for specifying the surge arrival time, when setting each level for specifying the surge arrival time or changing the means for correcting the surge arrival time, work for each slave station Was necessary and required a lot of labor.
[0006]
The present invention is for solving the above-mentioned problems, and specifies the surge arrival time accurately from different waveforms depending on various conditions, and the setting for specifying the surge arrival time for the surge detected in each slave station, etc. It is an object of the present invention to provide a fault location system that can easily change the above.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, in the fault location system of the present invention, the zero point voltage and the zero phase current of the transmission / distribution line are detected, and data based on the detection result is transmitted. A plurality of slave stations, and a master station that calculates a difference in surge arrival time of each slave station from data transmitted from each of the slave stations, and locates a failure point based on the difference in the surge arrival time A fault location system that is configured, wherein each of the slave stations records a detection circuit that detects a sudden change in the commercial frequency of the zero-phase voltage, and records the waveform data of the zero-phase current. A write control means for holding waveform data in a certain range up to a point in time when a sudden change in the zero phase voltage is detected for the zero phase current when a sudden change in the commercial frequency of the phase voltage is detected; Retained A controller that transmits waveform data in a certain range and time data indicating a point in time when a sudden change in the zero-phase voltage is detected to the master station, the master station transmitting waveform data and time data transmitted from the slave station And calculating means for calculating the surge arrival time at the slave station. As a result, the occurrence of a ground fault is detected by the zero-phase voltage at each slave station, and the surge arrival time is calculated based on the waveform data of the zero-phase current. Can be accurately identified. In addition, since the master station is provided with calculation means for calculating the surge arrival time, various settings for specifying the surge arrival time and the correction means can be easily changed.
[0008]
Further, the calculation means of the master station calculates a reference surge arrival time based on the waveform data and the time data transmitted from one slave station among the slave stations that detected a sudden change in the zero-phase voltage, Transmitting the reference surge arrival time to another slave station that has detected a sudden change in the zero-phase voltage and giving a reply instruction of waveform data near the reference surge arrival time, and the controller of the other slave station sends the reply instruction In response, the waveform data near the reference surge arrival time held by the write control means is returned to the master station, and the calculation means of the master station converts the waveform data returned from the other slave stations. Based on this, the surge arrival time at each slave station is calculated. As a result, when calculating the surge arrival time at the other slave station based on the surge arrival time at one slave station, efficiently collect the waveform data necessary to identify the surge arrival time at each slave station And transmission efficiency to the master station can be improved.
[0009]
The slave station used in the fault location system is a slave station that detects a zero-phase voltage and a zero-phase current of a transmission / distribution electric line, and transmits data based on the detection result to the master station. The station records the sudden change in the commercial frequency of the zero-phase voltage of the transmission and distribution line, and the waveform data of the zero-phase current of the transmission and distribution line, and the detection circuit detects the sudden change of the zero-phase voltage And a write control means for holding a certain range of waveform data up to the point in time when a sudden change in the zero-phase voltage is detected for the zero-phase current in the transmission and distribution line. The arrival time can be specified accurately. The means for calculating the surge arrival time may be provided in either the slave station or the master station.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing a schematic configuration of the fault location system according to the present embodiment, FIG. 2 is a block diagram showing a schematic configuration of a slave station used in the fault location system, and FIG. 3 is used in the fault location system. It is a block diagram which shows schematic structure of the parent station made.
The fault location system according to the present embodiment is installed in the transmission / distribution line 10 and has a plurality of slave stations 1A, 1B that monitor and detect the zero-phase current and zero-phase voltage of the transmission / distribution line, and the slave stations 1A, 1B. And the master station 2 that receives data based on the detection result and determines the position of the failure point 12 based on the data. The slave stations 1 </ b> A and 1 </ b> B have a voltage / current sensor 3 that detects a zero-phase voltage and a zero-phase current of the transmission and distribution line 10. The slave stations 1A and 1B receive the time signal from the GPS satellite 11.
[0011]
As shown in FIG. 2, the slave stations 1A and 1B include an antenna 21, a GPS receiver 22, a synchronous frequency dividing circuit 23, a high-speed A / D conversion circuit 24, a zero-phase voltage detection circuit 25, and a write control. A circuit 26, a memory 27, a controller (CPU) 28, and a data communication device 29 are provided.
The GPS receiver 22 receives a time signal from the GPS satellite 11 by the antenna 21 and outputs a clock signal in increments of 1 second to the synchronous frequency dividing circuit 23. The synchronization frequency dividing circuit 23 synchronizes the internal high-speed clock with the clock signal output from the GPS receiver 22 and outputs the counter value to the write control circuit 26.
The high-speed A / D conversion circuit 24 digitally converts the zero-phase current signal from the voltage / current sensor 3 and outputs digital data to the write control circuit 26. The zero-phase voltage detection circuit 25 monitors the zero-phase voltage from the voltage / current sensor 3, detects a sudden change in the commercial frequency region, and outputs a detection signal to the write control circuit 26. The voltage / current sensor 3 detects the zero-phase voltage and the zero-phase current. However, since the change of the current is more remarkable than the voltage in general, the zero-phase voltage is used to detect the ground fault, and the surge arrival time is detected. Specifically, waveform data of zero phase current is used.
The write control circuit 26 constantly records and updates the waveform data digitally converted by the high-speed A / D conversion circuit 24 in the memory 27 arranged in a virtual ring shape, and detects the detection output from the zero-phase voltage detection circuit 25. The recording operation for the memory 27 is controlled by the signal. Further, a time stamp based on the counter value of the synchronous frequency dividing circuit 23 is recorded in the memory 27.
A controller (CPU) 28 controls transmission of waveform data and time stamps recorded in the memory 27 by using a data communication device 29 in response to a command from the master station 2. The data communication device 29 performs data transmission with the master station 2 using communication means such as PHS.
[0012]
On the other hand, as shown in FIG. 3, the master station 2 includes a data communication device 31, a controller (CPU) 32, an auxiliary storage device 33, and an input / output device 34. The data communication device 31 performs data transmission with the data communication devices 29 of the slave stations 1A and 1B. The controller 32 instructs the slave stations 1A and 1B to transmit waveform data, calculates the surge arrival times of the slave stations 1A and 1B based on the waveform data collected from the slave stations 1A and 1B, and the like. Each process of the fault location determination process based on the surge arrival time is performed.
The auxiliary storage device 33 is composed of a hard disk or the like, and the processing at the controller (CPU) 32 such as the surge arrival time and the failure point position calculated by the controller (CPU) 32 based on the data transmitted from each of the slave stations 1A and 1B. Data necessary for recording is recorded and saved.
The input / output device 34 includes a keyboard for inputting data necessary for processing by the controller (CPU) 32, a CRT for displaying processing results, a printer for printing processing results, and the like.
[0013]
With the above configuration, a method for specifying the arrival surge time of each slave station used for locating the failure point position in the event of a ground fault in the transmission / distribution line will be described.
In each of the slave stations 1A and 1B, the zero-phase voltage detection circuit 25 detects a sudden change in the zero-phase voltage in the commercial frequency band caused by the ground fault at the failure point 12, and outputs a detection signal to the write control circuit 26. The write control circuit 26 stops the recording of the waveform data of the zero-phase current to the memory 27 when the detection signal is input, holds the waveform data that has been recorded up to that point in the memory 27, and at the same time the controller (CPU ) 28. The write control circuit 26 records a time stamp based on the counter value of the synchronous frequency dividing circuit 23 in the memory 27 together with the waveform data, and outputs the time stamp to a controller (CPU) 28. The controller (CPU) 28 transmits the input waveform data and time stamp to the master station 2 using the data communication device 29.
The controller (CPU) 32 of the master station 2 determines the surge arrival point when a ground fault occurs based on the waveform data transmitted from one slave station 1A serving as a reference, and uses the time stamp to determine the surge arrival point. Time (hereinafter referred to as “reference surge arrival time”) is calculated. As the reference slave station 1A, for example, the slave station closest to the power supply installed near the substation is applicable.
Based on the calculated reference surge arrival time, the controller (CPU) 32 of the parent station 2 transmits a waveform data return instruction near the reference surge arrival time from the other slave station 1B by the data communication device 31. As another slave station, for example, the slave station 1B installed on the distribution line where the slave station 1A is installed corresponds.
In response to a reply instruction from the master station 2, the controller (CPU) 28 of the slave station 1B stores waveform data in a limited high-frequency region near the reference surge arrival time from the waveform data held in the memory 27. It returns with the communication apparatus 29.
The controller (CPU) 32 of the master station 2 analyzes the waveform data returned from the slave station 1B, calculates the surge arrival time of each slave station, and determines the failure point based on the difference in surge arrival time of each slave station. Perform orientation. For calculating the surge arrival time of each slave station, a known method for correcting the surge arrival time, such as a two-potential method, is used.
[0014]
A method of calculating the failure point position using the surge arrival time at each of the slave stations 1A and 1B calculated in this way will be described.
Assuming that the propagation speed v of the surge generated by the ground fault between the slave stations 1A and 1B is constant, the surge arrival time at each slave station 1A and 1B is from the failure point 12 to each slave station 1A and 1B. This is proportional to the distances L1 and L2.
Therefore, from the difference between the length L of the transmission / distribution electric line between the slave stations 1A and 1B and the surge arrival times T1 and T2, using the calculation formula “L1 = (L + (T1−T2) × v) / 2”, A distance L1 from the station 1A to the failure point 12 can be calculated.
[0015]
As described above, the fault location system according to the present embodiment includes the zero-phase voltage detection circuit 25 that monitors the change in the zero-phase voltage and outputs the waveform data obtained by A / D converting the zero-phase current. A / D conversion circuit 24 is provided, a zero-phase voltage is used to detect the occurrence of a ground fault, and waveform data indicating a change in the zero-phase current is used to specify the surge arrival time. Therefore, it is possible to accurately specify the surge arrival time based on the waveform data of the zero-phase current having a relatively remarkable change, and it is possible to reduce erroneous detection by detecting the change of the zero-phase voltage.
In addition, each slave station has means for transmitting the waveform data and time data recorded at the time of detecting a sudden change in zero phase voltage to the master station, and the surge arrival time from the waveform data and time data received from each slave station in the master station Therefore, it is possible to easily change the setting and the correction method for specifying the surge arrival time.
Also, the reference surge arrival time is specified from the waveform data and time data acquired from one reference slave station, the reference surge arrival time is transmitted to other slave stations, and the reference surge arrival from other slave stations Since the waveform data near the time is returned, it is possible to efficiently collect the waveform data necessary for specifying the surge arrival time of each slave station.
[0016]
In the above embodiment, the surge arrival time of each slave station is calculated by the controller (CPU) 32 provided in the master station. However, the waveform data and time recorded in the memory 27 of each slave station are calculated. Based on the stamp, the surge arrival time may be calculated by the controller (CPU) 28 of each slave station. In this case as well, by using the zero-phase voltage to detect the occurrence of the ground fault and using the waveform data indicating the change in the zero-phase current to specify the surge arrival time, it is possible to reduce false detections and the surge arrival time. Accurate identification is possible.
[0017]
【The invention's effect】
Each slave station constituting the fault location system of the present invention has a detection circuit that detects a change in the zero-phase voltage of the transmission and distribution line, and the detection circuit detects a sudden change in the zero-phase voltage for the zero-phase current of the transmission and distribution line. Write control means for holding a predetermined range of waveform data up to the detected time point, and a predetermined range of waveform data held by the write control means and time data indicating a time point when a sudden change in the zero-phase voltage is detected A controller for transmitting to the master station, and the master station includes a calculation means for calculating the surge arrival time at each slave station based on the waveform data and time data transmitted from each of the slave stations. It is possible to accurately specify the surge arrival time from the waveform and easily change the setting for specifying the surge arrival time for the surge detected by each slave station.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of a failure point location system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a slave station constituting the failure point location system of the present invention.
FIG. 3 is a block diagram showing a schematic configuration of a master station constituting the failure point location system of the present invention.
[Explanation of symbols]
1A, 1B Slave station 2 Master station 3 Voltage / current sensor 10 Transmission / distribution line 11 GPS satellite 12 Failure point 21 GPS antenna 22 GPS receiver 23 Synchronous frequency dividing circuit 24 High-speed A / D conversion circuit 25 Zero-phase voltage detection circuit 26 Control circuit 27 Memory 28 Controller 29 Data communication device 31 Data communication device 32 Controller 33 Auxiliary storage device 34 Input / output device

Claims (3)

A plurality of slave stations that are installed in the transmission / distribution line, detect zero-phase voltage and zero-phase current of the transmission / distribution line, and transmit data based on the detection results, and the data transmitted from each of the slave stations A failure point location system comprising a master station that calculates a difference in surge arrival time of each slave station and determines a failure point location based on the difference in surge arrival time,
Each of the slave stations includes a detection circuit that detects a sudden change in the commercial frequency of the zero-phase voltage;
The waveform data of the zero phase current is recorded, and when the detection circuit detects a sudden change in the commercial frequency of the zero phase voltage, the waveform in a certain range up to the time when the sudden change of the zero phase voltage is detected for the zero phase current. Write control means for holding data;
A controller that transmits to the master station time data indicating the time point when the waveform data in the certain range held by the write control means and the sudden change in the zero-phase voltage are detected;
The fault location locating system, wherein the master station includes a calculation means for calculating a surge arrival time at the slave station based on waveform data and time data transmitted from the slave stations. The calculation means of the master station calculates a reference surge arrival time based on the waveform data and the time data transmitted from one slave station among the slave stations that detected a sudden change in the zero phase voltage, and the zero phase Sending the reference surge arrival time to other slave stations that have detected a sudden change in voltage, giving a reply instruction for waveform data near the reference surge arrival time,
In response to the reply instruction, the controller of the other slave station returns the waveform data near the reference surge arrival time held by the write control means to the master station,
2. The fault location system according to claim 1, wherein the computing unit of the master station calculates a surge arrival time at each slave station based on waveform data returned from the other slave stations. As a slave station used in the fault location system, it is a slave station that detects the zero-phase voltage and zero-phase current of the transmission and distribution line, and transmits data based on the detection result to the master station,
Each of the slave stations includes a detection circuit that detects a sudden change in the commercial frequency of the zero-phase voltage;
The waveform data of the zero phase current is recorded, and when the detection circuit detects a sudden change in the commercial frequency of the zero phase voltage, the waveform in a certain range up to the time when the sudden change of the zero phase voltage is detected for the zero phase current. A slave station comprising write control means for holding data.

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