JPS632066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surge reception type fault locator device that does not require correction of the transmission delay time of a time reference pulse.

Fault locator devices for locating fault points such as ground faults on power transmission lines include radar-type fault locators that send impulses from the transmitting end or receiving end and determine the locating distance based on the arrival time of the reflected signal from the fault point. There are ortholocators and surge receiving type (P-type, B-type) fault locators that determine the distance from the difference in time between propagation of surge noise (hereinafter simply referred to as surge) generated at the fault point to the power transmitting end and the power receiving end. The present invention is a surge receiving type fault locator device (P
This is related to the improvement of (shape).

1 and 2 are block diagrams showing the configuration of a conventional surge reception type fault locator (P type) and diagrams showing its operating principle.

In Fig. 1, 1 is a power transmission line, and at the A station and B station at both ends of the line, there are coupling devices c.
It is coupled to a master station device 4 and a slave station device 5 via terminals 2 and 3. The master station device 4 and the slave station device 5 are connected by a downstream transmission path 6 and an upstream transmission path 7. The master station device 4 includes a reference pulse generator 11,
Modulation circuit M12, counter 13, demodulation circuit D1
4. The slave station device 5 includes a calculation circuit 15, a reference pulse regeneration circuit 21, a demodulation circuit D22, and a counter 2.
3. Contains a modulation circuit M24.

In the surge reception type fault locator (P type), the master station device 4 converts the time reference pulse generated by the reference pulse generator 11 into an appropriate modulation signal by the modulation circuit 12, and transmits the transmission line 6. Then, the data is constantly transmitted to the slave station device 5. The time counter 13 of the master station device is started by this time reference pulse, stopped by reception of the surge, and holds the measured value. In the slave station device, the demodulation circuit 22 demodulates the modulated signal that has arrived via the transmission line 6, and then the reference pulse regeneration circuit 21 regenerates the time reference pulse. The time counter 23 of the slave station device is started by the reproduced time reference pulse, stopped by reception of the surge, and holds the measured value.

The measured value held in the counter 23 of the slave station device is converted into a modulated signal by the modulation circuit 24,
It is sent to the master station device via the transmission path 7. Demodulation circuit 1
4 demodulates this modulated signal and reproduces the measured value.
The measured value of the master station in the counter 13 and the reproduced measured value of the slave station are added to the arithmetic circuit 15.
In the arithmetic circuit 15, based on the difference between the two measured values,
The distance X from the master station device to the accident point is calculated and output.

In Figure 2, A indicates the case where the time reference pulse sent from the master station device has already exceeded the accident point at the time of the accident occurrence, and B shows the case where the time reference pulse is just before the accident point at the time of the accident occurrence. It shows. Although the time reference pulse propagates on the transmission line and the surge propagates on the power transmission line at the speed of light, for convenience, the time measurement count value is expressed in terms of distance.
Therefore, for example, the distance A (m) is the propagation time A/Vp
(sec) (Vp is the speed of light (m/sec)).

In Figure 2 A and B, a is from the master station to
Point (m) shows the positional relationship between the surge and the time reference pulse at the moment the accident occurred. In both figures, a(m) indicates a count value converted into a distance from the transmission of the time reference pulse to the occurrence of an accident in the master station device. Further, in FIG. 2B(a), P(m) indicates the interval (distance conversion) of time measurement pulses sent from the master station.

In FIGS. 2A and 2B, b indicates the positional relationship between the surge and the time reference pulse at the moment the surge reaches the master station. In this case, X(m) is further counted after the time reference pulse is sent from the master station, so the count value M when the surge reaches the master station is:
It is clear that M=(a+X)(m) in either case.

In FIGS. 2A and 2B, c indicates the positional relationship between the surge and the time reference pulse at the moment the surge reaches the slave station. In either case, the slave station's counter is started by the time reference pulse that precedes the surge. Therefore, Fig. 2 A, c
In the case of , the count value S of the slave station when the surge reaches the slave station is S=(a-X)(m), but in the case of Figure 2B and c, the count value S of the slave station when the surge reaches the slave station is Then the counter starts, so the count value S
becomes S={P-(X-a)}(m).

Based on the above relationship, the arithmetic circuit 15 can determine the distance X (m) between the master station device and the accident point using the count values M and S from the following relationship.

X=1/2(M-S), M≧S...(1) X=1/2(M-S)+P/2, M<S...(2) The count value S of the slave station device is , is sent to the master station device via the transmission path 7, but it goes without saying that the transmission delay time is irrelevant to the above calculation.

In the surge reception type fault locator, as is clear from the above, the transmission delay time of the time reference pulse transmitted from the master station device to the slave station device is the same as the time it takes for the surge to propagate between stations A and B. The condition is that they are equal. Transmission of time reference pulses usually uses microcircuits or carrier lines, but a modem is required for signal transmission;
The above-mentioned conditions generally do not hold due to the transfer device and the difference in route. In such a case, the count value at the slave station device includes the time difference between the time reference pulse delay time and the surge propagation time, resulting in an error in the location value.

FIG. 3 is a diagram for explaining the occurrence of orientation errors when the time reference pulse delay time is longer than the surge propagation time by ΔL. In the same figure, A indicates that the time reference pulse sent from the master station device is
A case where the accident occurrence point has already been exceeded is shown, and B shows a case where the time reference pulse is before the accident occurrence point when the accident occurs.

In Figure 3 A and B, a is from the master station to
Point (m) shows the positional relationship between the surge and the time reference pulse at the moment the accident occurred, and a(m) shows the count value converted to the distance from the transmission of the time reference pulse from the master station to the occurrence of the accident. There is.

In FIGS. 3A and B, b indicates the positional relationship between the surge and the time reference pulse at the time when the surge reaches the master station;
(m) is counted, so the count value M when the surge reaches the master station is M =
(a+X)(m), which is no different from the case in FIG.

In FIGS. 3A and 3B, c indicates the positional relationship between the surge and the time reference pulse at the moment the surge reaches the slave station. Now, assuming that the time reference pulse delay time is longer than the surge transmission time by ΔL (distance conversion), the count value S of the slave station when the surge reaches the slave station in Fig. 3A and c is
=(a-X-ΔL)(m). On the other hand, Fig. 3B,
At point c, counting is performed from the previous time reference pulse as in the case of FIG. 2, so the count value S becomes S={P-(X-a+ΔL)}(m). Note that when the time reference pulse delay time is shorter than the surge propagation time by ΔL, the above relationships are S=(a-X+ΔL)(m) and S={P-(X+a-
It is clear that ΔL)}(m).

From these relationships, the distance X (m) from the master station device to the point where the accident occurred is as follows: −S)+P/2〓ΔL/2, M<S...
…(4), and in any case, the orientation value has an unknown quantity ΔL
(m) is included.

Therefore, in such a case, since the time reference pulse is a signal having a constant period, a conventional method has been taken in which a delay circuit is provided in the slave station device to apparently satisfy the above-mentioned conditions. However, it is extremely difficult to prove that such conditions are met by directly measuring the transmission delay time of the time reference pulse and the surge.

For this purpose, a fault locator device is actually installed on the power transmission line to be monitored, and a fault is artificially caused at an appropriate point at both ends or in the middle of the transmission line, or a high-voltage impulse simulating an accident surge is applied to locate the fault locator. The aforementioned delay correction value had to be determined by determining the difference between the value obtained and the actual distance on the transmission line.

Such tests must be carried out with the transmission line down, or even without it, which not only requires extensive and complex operations, but also changes in the configuration of the transmission line that transmits the time-based pulses. In such cases, such a test must be conducted each time, which is extremely complicated and costly.

The present invention attempts to eliminate such drawbacks of the prior art, and its purpose is to provide a surge reception type fault locator device that does not require correction of the transmission delay time of the time reference pulse. . In order to achieve this purpose, the surge reception type fault locator device of the present invention receives surge noise of a power transmission line by a master station device and a slave station device installed at both ends of the power transmission line, and locates the point of occurrence of the accident. In a surge reception type fault locator device, a reference pulse generation circuit of a master station and a slave station each generates time reference pulses of the same period, and the time reference pulses of the master station and slave stations are transmitted with equal delay times. a reference pulse regeneration circuit of the slave station and the master station that receives the time reference pulse of the other station via the transmission line and reproduces the time reference pulse of the other station, and a first pulse regeneration circuit that measures the time difference between the time reference pulse of the master station and the power line surge at the master station. a time measurement circuit, a second time measurement circuit that measures the time difference between the reproduction time reference pulse of the slave station reproduced at the master station and the power transmission line surge; a third time measuring circuit that measures a time difference in a slave station; a fourth time measuring circuit that measures a time difference between the reproduction time reference pulse of the master station reproduced in the slave station and the power line surge; The measured value of the first time measuring circuit and the fourth
A first arithmetic circuit that calculates the difference between the measured value of the time measuring circuit and a second arithmetic circuit that calculates the difference between the measured value of the second time measuring circuit and the third time measuring circuit. and a third arithmetic circuit that calculates the correct distance from the master station or slave station to the accident point from the difference between the outputs of the first and second arithmetic circuits and the length of the power transmission line.

Examples will be described below.

FIG. 4 is a block diagram showing the structure of one embodiment of the surge receiving type fault locator device of the present invention. In the figure, the numbers 1, 2, 3, 4, 5, 6,
The representation of 7 is the same as in Figure 1. 8 is a data transmission line.

In the master station device 4, 31 is a reference pulse generation circuit, 32 is a modulation circuit M, 33 is a first counter,
34 is a demodulation circuit D, 35 is a reference pulse regeneration circuit,
36 is a second counter, 37 is a demodulation circuit D, 38
is a separation circuit, 39 is a first arithmetic circuit, and 40 is a second
, and 41 is a third arithmetic circuit. Further, in the slave station device 5, 51 is a reference pulse generation circuit, 52 is a modulation circuit M, 53 is a first counter,
54 is a demodulation circuit D, 55 is a reference pulse regeneration circuit,
56 is a second counter, 57 is a multiplex circuit, and 58 is a modulation circuit M.

The master station device 4 and the slave station device 5 generate time reference pulses from reference pulse generation circuits 31 and 51, respectively, and convert them into appropriate modulation signals by modulation circuits 32 and 52, respectively, and transmit transmission lines 6 and 7, respectively. The data is then transmitted to the slave station device 5 and the master station device 4, respectively. Although it is not necessary that the time reference pulse of the master station device and the time reference pulse of the slave station device be synchronized, it is necessary that their transmission intervals be equal. The time counter 33 of the master station device is started by the time reference pulse of the master station, stopped by reception of the power transmission line surge, and holds the measured value Mm.
Similarly, the time counter 53 of the slave station device starts with the time reference pulse of the slave station, stops upon reception of the power transmission line surge, and returns its measured value Ss.
hold.

Furthermore, the master station device 4 and the slave station device 5 each have demodulation circuits 34 and 54, and demodulate the modulated signals of the slave station device and the master station device received via the transmission lines 7 and 6, respectively, and reproduce the reference pulse, respectively. Input to circuits 35 and 55. As a result, the reference pulse regeneration circuit 3
5 and 55 reproduce time reference pulses of the slave station and the master station, respectively. Master station time counter 36
is started by the regenerated slave station time reference pulse, stopped by reception of the power line surge, and holds its measured value Ms. Similarly, the time measuring counter 56 of the slave station is started by the reproduced time reference pulse of the master station, stopped by reception of the power transmission line surge, and holds the measured value Sm.

The signals of the measured values Ss and Sm held in the counters 53 and 56 of the slave station device are multiplexed by a multiplexing circuit 57, converted into an appropriate modulation signal by a modulation circuit 58, and then transmitted via a transmission line 8. Sent to the master station device. In the master station device, this signal is demodulated in a demodulation circuit 37, and the demodulated signal is demultiplexed in a separation circuit 38 to generate measurement values Sm and Ss.
Sm and Ss are input to arithmetic circuits 39 and 40, respectively. The calculation circuits 39 and 40 each have a measured value.
Mm and Ms are input, respectively (Mm−
Sm) and (Ss−Ms) and output them respectively.
Produces X′, Y′.

Now, in FIG. 4, it is assumed that the transmission delay times of the transmission lines 6 and 7 that mutually transmit the time reference pulse are equal. Since both the master station device and the slave station device transmit the same time reference pulse, the reference pulse generation circuit, modem, etc. should have the same configuration, and if a micro line is used as the transmission path, the outbound and return paths should have the same configuration. This is because by doing so, it is possible to match the delay times as a whole. However, since delay compensation between the power transmission line and the time-based pulse transmission line is not performed, the calculated values X′ and Y′ obtained using the same method as the conventional device contain errors, but The error values are equal. Now, assuming that the delay in the transmission path is larger than that in the power transmission line, and the distances from the master station and slave station to the fault point are X and Y, respectively, then from the relationship of equations (3) and (4), X' = X + ΔL / 2 = 1/2 (Mm - Sm), Mm≧Sm ... (5) or X' = X + ΔL / 2 = 1/2 (Mm - Sm) + P / 2, Mm < Sm ... (6) Y' = Y+ΔL/2 = 1/2(Ss-Ms), Ss≧Ms...(7) or Y'=Y+ΔL/2 1/2(Ss-Ms)+P/2, Ss<Ms...(8) These In each equation, when the difference H between the corresponding values X' and Y' is calculated, the error ΔL/2 included in each value is canceled out in the difference H. Therefore, the following relationship holds true.

H=X'-Y'=X-Y...(9) Furthermore, if the total length of the transmission line is L, L=X+Y, so from the relationship in equation (9), the connection between the master station and the fault point can be calculated as follows. The correct distance X is found.

X=1/2(H+L)...(10) Similarly, the correct distance Y between the slave station and the accident point can be found using the following formula.

Y=1/2(L-H)...(10)' In Fig. 4, the arithmetic circuit 41 calculates equations (9), (10), and (10)' and outputs the target value X or Y. occurs.

Note that the data transmission path 8 is for transmitting the count values Sm and Ss in the slave station device to the master station device, and it goes without saying that there is no restriction regarding delay time. Also, without providing a data transmission line 8 in particular, the count value can be determined by an appropriate multiplexing circuit.
It is also possible to omit this by multiplexing Sm and Ss with the time reference pulse and transmitting the same.

As explained above, according to the surge receiving fault locator of the present invention, there is no need for large-scale and complicated tests such as artificial failure tests on power transmission lines and high-voltage impulse application tests for delay correction, which were indispensable in the past. In addition, even if a situation occurs that causes a change in delay time, such as a change in the configuration of a transmission path during operation, it is extremely effective because no readjustment is required.

[Brief explanation of the drawing]

Figures 1 and 2 are block diagrams showing the configuration of a conventional surge reception type fault locator (P type) and its operating principles, Figure 3 is a diagram to explain the occurrence of orientation errors, and Figure 4. 1 is a block diagram showing the configuration of an embodiment of a surge reception type fault locator according to the present invention. 1...Power transmission line, 2, 3...Coupling device c, 4...
Master station device, 5... Slave station device, 6, 7, 8... Transmission line, 11... Reference pulse generator, 12... Modulation circuit M, 13... Counter, 14... Demodulation circuit D,
15...Arithmetic circuit, 21...Reference pulse regeneration circuit, 22...Demodulation circuit D, 23...Counter, 2
4...Modulation circuit M, 31...Reference pulse generation circuit, 32...Modulation circuit M, 33...Counter, 3
4...Demodulation circuit D, 35...Reference pulse regeneration circuit, 36...Counter, 37...Demodulation circuit D, 3
8...Separation circuit, 39, 40, 41...Arithmetic circuit, 51...Reference pulse generation circuit, 52...Modulation circuit M, 53...Counter, 54...Demodulation circuit D, 55...Reference pulse regeneration circuit , 56...Counter, 57...Multiple circuit, 58...Modulation circuit M.

Claims (1)

[Claims] 1. In a surge reception type fault locator device that locates the point of occurrence of an accident by receiving surge noise of a power transmission line with a master station device and a slave station device installed at both ends of the power transmission line, a time reference pulse of equal period is transmitted to each A reference pulse generation circuit for a master station and a slave station that generates a reference pulse, and a slave station that receives the time reference pulses of the master station and slave stations through transmission paths having equal delay times and reproduces the time reference pulses of the respective partner stations. and a reference pulse regeneration circuit of the master station, a first time measurement circuit that measures the time difference between the time reference pulse of the master station and the power transmission line surge in the master station, and a reproduction time reference pulse of the slave station regenerated in the master station. A second time measurement circuit that measures the time difference between the power transmission line surge and the power transmission line surge at the master station; a third time measurement circuit that measures the time difference between the time reference pulse of the slave station and the power transmission line surge at the slave station; a fourth time measurement circuit that measures the time difference between the reproduction time reference pulse of the reproduced master station and the power transmission line surge in the slave station; and measurement of the measured value of the first time measurement circuit and the fourth time measurement circuit. a first arithmetic circuit that calculates the difference between the measured value of the second time measuring circuit and the measured value of the third time measuring circuit; A surge reception type fault locator device characterized by comprising a third arithmetic circuit that calculates the correct distance from the master station or slave station to the fault point based on the difference in the output of the second arithmetic circuit and the length of the power transmission line. .