JPS5924271A - Receiving apparatus - Google Patents

Abstract

PURPOSE:To perform investigation with good result and simply, by sampling a result detected by a receiving apparatus used in investigating the faulty point of an aerial distribution wire line by a high voltage pulse applying method and subjected to signal treatment several times to display an average value. CONSTITUTION:The output of a second integrator 38 passed through a first filter 24 and an amplifier 26 from an antenna 18 to be subjected to signal treatment is subjected to data addition in an adder 25 through a sampling gate 50. After the preliminarily set number of data are added, they are subjected to an average value treatment in an average value treating part 54 through a detection display gate 40 by the gate signal from a gate signal generator 46 to be displayed by a detection meter 42. Even if a commercial frequency current including a high frequency wave component is instantaneously changed within the integrating time of a receiving apparatus in a section through which the commercial frequency current is flowed, the investigation of a faulty point can be performed extremely well and simpy without requiring the time for reading meter indication several times.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a receiving device, particularly a receiving device used for detecting a fault point on an overhead power distribution line using a high voltage pulse application method.

Conventionally, when a fault occurs on an overhead power distribution line, a high voltage pulse application method is used to search for the fault point. This involves applying a high-voltage pulse to a faulty line section, detecting the pulsed current flowing through the distribution line using a receiver equipped with an antenna, and searching for the point of a grounding fault. To investigate this, as shown in FIG. 1, a high voltage pulse having a waveform as shown in FIG. 2 is applied to the overhead power distribution line 12 by a high voltage pulse generator 10. Thereby, the current flowing through the power distribution line 12 is detected by the receiving device 20 having the antenna 18, and the ground fault point is searched. As shown in FIG. 1, the high voltage pulse generator 12 generates high voltage pulses by rapidly discharging the charge stored in the capacitor C1 using the switching element S. Resistor R1 and capacitor C2 shape the high voltage pulse. Distribution line 12ti,
It has a ground fault resistance of Rg between the ground fault point 16 and the earth 14, and has a ground capacitance of Cg after the ground fault point 16. On the other hand, a search coil type antenna 18 is used on the receiving device 20 side, and this antenna 18 is connected to the receiving device 20 via a lead wire 22.

In such a configuration, the high voltage pulse generator 10 applies a high voltage pulse between the distribution line 12 and the ground 14, while the receiving device 20 with the antenna 18 applies the high voltage pulse between the distribution line 12 and the ground 14.
The ground failure point is detected by detecting the pulse current flowing through the ground. In other words, if we integrate the current flowing through the line 12 due to the application of the above-mentioned high voltage pulse, (a) if there is a grounding fault on the line, the integrated value will be zero; (b) if there is an accident, the pulse will be generated. In the section from the device 10 to the fault point, the integral value is the fault current value.

(1) After an accident occurs, the integral value becomes zero in the section after passing through the accident point.

Therefore, by reading the integral value over a certain period of time, it is possible to distinguish between the above three types of values and search for the accident point. Here, since a differential circuit is isometrically interposed between the line 12 and the antenna 18, the above-mentioned integral is actually
A row is represented by two integration operations.

By the way, as an example of the conventional receiving device 2o//i is shown in FIG. 3, an M1 filter 24, an amplifier 26, a second . Third filter 28.30. 1st ° 2nd game) 32
, 44, gate signal generator 46, subtracter 34, first . It is composed of a second integrator 36, 38, a detection display gate 40, a detection meter 42, etc. First filter 24
is a filter for commercial frequency removal, and the second
The filter 28 is a high-pass filter, and the third filter 30 is a low-pass filter. Further, FIG. 4 shows the signal fe at each part of the receiving device 2o shown in FIG.
A waveform chart of '+''t gle g2y g3 is shown below.The operation of the receiving apparatus 20 will be described below based on FIGS. 3 and 4.

from the antenna 18 to the first filter 24. amplifier 26, second filter 28. Signal f passing through the third filter 30
The gate signal generator 46 detects the first instant of time and generates a series of gate signals gL g 2 * g 3 . First, from the time of reception, the first
The gate 32 is opened for a certain period of time, and the first integrator 36. The second integrator 38 integrates twice. Next, the integration contents of the first integrator 36 are returned to the initial state within a short period of time, for example, about 10 μs after the first gate 32 is closed. Next, the second gate 44 is opened for the same time as the first gate 32 after a time delay of an integer multiple of the commercial frequency period from the first reception time, and the polarity of the output signal f is inverted by the subtracter 34. Integration is performed twice in the same way as when the 1 gate 32 is open. The polarity is reversed because the first gate 32 is closed.

Next, the detection display gate 40 is opened for a period shorter than the high voltage pulse application period to cause the detection meter 42 to indicate the contents of the second integrator 38. Therefore, by reading the indication of the detection meter 42, the above-mentioned ground failure point can be detected.

By the way, because conventional receiving devices are configured as described above, accidents can occur, for example, in sections where complex and large stray currents flow through common ground lines, or in sections with double overhead lines that include systems with many unique loads. When searching for a point, for an instantaneous change in the commercial frequency current of the line, (first gate output) - (second gate output); becomes 0 and the second
The output of integrator 38 is disturbed. For this reason, reading the indicated value of the detection meter 42 only once may result in a complete determination, and therefore, the direction of the accident point cannot be correctly determined unless the indicated value is read multiple times. .

This invention was made in view of the above-mentioned conventional problem, and its purpose is to prevent the above-mentioned commercial frequency current from flowing within the integration time of the receiving device in a section where a commercial frequency current containing harmonic components is flowing. It is an object of the present invention to provide a receiving device which can perform an extremely good and easy search by using a stable display even when there is an instantaneous change.

In order to achieve the above object, the present invention detects the pulsed current flowing through the overhead distribution line through an antenna due to high voltage pulses repeatedly applied to the line, and processes this detection signal by signal processing. In the receiving device for detecting a ground fault point on the railway line, the results detected and signal processed by the receiving device are sampled multiple times and the average value thereof is displayed. .

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

In the following description, descriptions of parts common to the conventional example described above will be omitted, and only parts that are different will be mainly described.

FIG. 5 shows an embodiment of a receiving device 56 for detecting fault points in overhead distribution lines according to the present invention. This receiving device 56
It is used in the condition shown in the figure. By the way, this receiving device 56 is different from the conventional receiving device 20 described above.
A sampling gate 50 and an adder 52 are attached. This sampling gate 50 and adder 52 are similar to the second integrator 38 in the conventional receiving device 20 of FIG.
and the detection display gate 400. Further, an average value processing section 54 is attached, which is connected to the detection display gate 40.
and the detection meter 420. The rest of the configuration is the same as the conventional device shown in FIG.

Now, to explain the operation of the receiving device 56 configured as above, first, from the antenna 1st to the first filter 24. The output of the second integrator 38 which has passed through the amplifier 26 and has been subjected to signal processing passes through a sampling gate 50 and is data-added by an adder 52. After adding the data outside the preset number of times, the gate signal from the gate signal generator 46 is passed through the detection display gate 40, and the average value is processed by the average value processing section 54, and then displayed on the detection meter 42. Ru.

In addition, suntouring calculations of the above signal processing results, etc.
Instead of using individual circuits, it can also be configured using a microprocessor, which is a general-purpose information processing means.

As described above, according to the present invention, by providing the function of displaying the average value of the signal processing results, the integration time of the receiving device is Even if the commercial frequency current changes instantaneously, the trouble point can be detected very easily and efficiently without the trouble of reading the meter reading many times as in the conventional case.

[Brief explanation of the drawing]

Figure 1 shows the state in which the grounding accident point is being explored, Figure 2
The figure is a diagram showing the waveform of the high voltage pulse of the first high voltage pulse generator, Figure 3 is a block diagram showing an example of a conventional receiving device for fault point exploration, and Figure 4 is a waveform chart diagram showing its operation. , FIG. 5 is a block diagram showing an embodiment of a receiving apparatus according to the present invention. The same members in each figure are given the same reference numerals, 10 is a high voltage pulse generator, 12 is a power distribution line, 14 is the ground, 16 is a ground fault point, 18 is a search coil type antenna, 20 is a conventional receiving device, 22 is a lead wire, 24 is a first filter for removing commercial frequencies, 26 is an amplifier, 28 is a second filter for high-pass, 30 is a third filter for low-pass,
32 is a first gate, 34 is a subtracter, 36 is a first integrator, 38 is a second integrator, 4o is a detection display gate, 42 is a detection meter, 44 is a second gate, 46 is a gate signal generator, 50 is a sampling gate, 52 is an adder, 54 is an average value processing section, and 56 is a receiving device according to the present invention. Agent Patent Attorney Shin Kuzuno − (Haka-Name)

Claims (1)

[Claims] (11) The pulse current flowing through the overhead distribution line is detected via an antenna due to high voltage pulses repeatedly applied to the overhead distribution line, and this detection signal is processed and A receiving device for searching for a ground fault point in a ground fault, characterized in that the results detected by the receiving device and subjected to signal processing are sampled a plurality of times, and the average value thereof is displayed. (2. The receiving device according to claim (1), comprising a microprocessor that performs sampling and average value calculation of the signal processing results.