JPH0213983Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a voltage detection function to determine whether the AC transmission/distribution line is being charged or not being charged when connecting it at a midpoint, and then This invention relates to a phase detector that uses a phase detection function to determine whether the in-phase or out-of-phase is in phase when the electrical circuit is being charged.

Generally, when repairing three-phase power transmission and distribution lines, etc., the construction section is electrically disconnected, the wires are replaced, etc., and then electrically reconnected after the construction is completed. For this reconnection, for example, as shown in FIG. 1, electric wires 3a, 3b, 3c, 3a',
Contact the phase detectors 4 and 5 to 3b' and 3c' to confirm that the electric circuits on both sides to be connected, for example 3c and 3c', are in a charged state, and then make sure that both electric wires 3c and 3c' are in the same phase. must be confirmed. This is because when the electric wires 3c and 3c' on both sides are connected by the vacuum switch 6c, a short circuit will occur if their charging voltages are not in the same phase.

The required performance of such phase detectors 4 and 5 is that the detection level for determining whether or not charging is being set to an appropriate value, and that the detected phase has high accuracy.

The present invention has been devised for the purpose of satisfying the above requirements, and an embodiment of the present invention shown in the drawings will be described below.

The structure of the phase checker 4 on the transmitting side is shown in FIG. 2, and the structure of the phase checker 5 on the receiving side is shown in FIG. The main body of the phase detector on the side, 8 is the phase detector circuit B described later.
9 and 10 are hook-shaped hanging fittings protruding from the upper parts of the phase detector bodies 7 and 8, respectively, and 11 and 12 are hook-shaped hanging fittings provided at the lower parts of the phase detector bodies 7 and 8, respectively. The protruding legs 13 and 14 are operating insulating rods connected to the legs 11 and 12 via universal joints 15 and 16, and 17 and 18 are transmitting antennas built into the legs 11 and 12, respectively. and receiving antenna, 1
Reference numerals 9 and 20 indicate indicator lights protruding from the phase detector bodies 7 and 8, respectively, and 21 a sound generator fixed to the phase detector body 8 on the receiving side.

The phase detector having the above configuration is used in a state as shown in FIG. 4 or FIG. 5.

The usage example shown in Figure 4 is a case where three wires to be phase tested are stretched vertically in parallel, and one insulating rod
A worker holding 3 and 14 climbs up the utility pole 1 and holds the wires 3c and 3c on both sides to be phase-tested with the hanging fittings 9 and 10 of the phase checker.
It is suspended from 3c'. To explain the work procedure in this case, first, the hanging fitting 1 of the phase detector 5 on the receiving side
0 is suspended from one electric wire 3c'. Then, the internal phase detection circuit B detects whether or not charging is in progress, and when charging is in progress, the indicator light 20 blinks,
The sound generator 21 is made to generate sound. At this time, the phase detection circuit B detects the phase of the charging voltage of the suspended electric wire 3c',
Generates the phase signal on the receiving side. Next, the transmitting side phase detector 4 is suspended from the other electric wire 3c. Then, the internal phase detection circuit A detects whether or not charging is in progress, and when charging is in progress, the indicator light 19 blinks. Furthermore, this phase detection circuit A detects the phase of the charging voltage of the electric wire 3c, carries this transmitting side phase signal on a radio wave, and emits it from the transmitting antenna 17. In the receiving side phase detector 5, this radio wave is received by the receiving antenna 18, and the internal phase detecting circuit B extracts the phase signal generated on the transmitting side. Then, this is compared with the phase signal generated on the receiving side, and if they match, the indicator light 20 is turned off, and the sound generator 21 is turned off.
The operator is informed that the charging voltages of the two electric wires 3c and 3c' to be connected are in phase with each other. If the two do not match, the blinking of the indicator light 20 and the operation of the sound generator 21 will continue, so the operator can know the mismatch. In this way, the device of the present invention confirms that the wire to be phase tested is being charged by turning on the indicator lights 19 and 20, and confirms that the phases match by turning off the indicator light 20 and turning off the sound generator 2.
Since it can be determined by the stoppage of step 1, it is highly reliable and easy to use.

In the usage example shown in Fig. 5, three electric wires to be phase tested are stretched horizontally in parallel, and the method of using the phase detectors 4 and 5 in this case is the same as described above. .

The phase detection circuits A and B built in the phase detectors 4 and 5 to perform the above operation will be explained with reference to FIGS. 6 and 7.

To explain the phase detection circuit A on the transmitting side, a is a detection unit that detects whether or not the electric wire on the transmitting side is in a charged state, and converts the AC waveform of the charging voltage into a rectangular wave that is its phase signal. c is a transmitting unit that emits the rectangular wave as a phase signal on a radio wave. d is a display unit that displays the charging state of the electric wire on an indicator light.

Each part will be explained in detail. Reference numeral 9 denotes a hanging fitting to be hung on the electric wires 3a, 3b, and 3c to be phase-detected, 17 is a transmitting antenna, and 17' is a conductor provided on the ground side of the phase detector 4, and the transmitting antenna 17 is used. 22 and 23 are detection capacitors connected in series between the hanging fitting 9 and the conductor 17', 24 is the stray capacitance between the conductor 17' and the ground, and 25 is whether the electric wires 3a, 3b, and 3c are in a charged state. A first level detection circuit 26 having a detection level V ₁ as shown in FIG. 10 is used to convert the AC waveform of the charging voltage of the electric wires 3a, 3b, and 3c into a rectangular wave as shown in FIG. 27 is a switching circuit that generates an ON output when the _first level detection circuit 25 detects the charging state; 28 is a switching circuit that generates an ON output when the first level detection circuit 25 detects the charging state; 29 is a low frequency oscillator circuit that oscillates when the input voltage performs a detection operation that is greater than its detection level _V2 ; 29 is a high frequency oscillator circuit that oscillates when switching circuit 27 generates an ON output; 30 is a mixing circuit; 31 is a high frequency oscillation circuit. The amplifier 32 is a flicker circuit that generates a flicker signal when the switching circuit 27 generates an ON output, and 33 is a driver circuit that blinks the indicator light 19 based on the output of the flicker circuit 32.

Also, to explain the phase detection circuit B on the receiving side,
b is a detection unit that detects whether or not the electric wire on the receiving side is in a charging state, and converts the AC waveform of the charging voltage into a rectangular wave that is a phase signal. A receiving section e receives the radio waves emitted from the phase detector on the transmitting side and extracts the rectangular wave on the transmitting side. f is the display section, which uses an indicator light and a sounder to notify you when the receiving wire is in a charged state and is out of phase with the transmitting side, and stops displaying when the rectangular waves on the transmitting and receiving sides are in the same phase. do.

Each part will be explained in detail. (10) is a hanging fitting to be hung on the electric wires 3a', 3b'3c' to be inspected;
18 is a receiving antenna, 18' is a conductor provided on the ground side of the transmitter 5, and the receiving antenna 18 is used. 34 and 35 are detection capacitors connected in series between the hanging fitting 10 and the conductor 18', 36 is a stray capacitance between the conductor 18' and the ground, 37 is an electric wire 3a',
A first level detection circuit 3b', 3c has a detection level _V1 as shown in FIG. a second level detection circuit having a verification level _V2 as shown in FIG. 40 is a frequency conversion circuit that converts a received high frequency signal into an intermediate frequency signal, 41 is an intermediate frequency amplification circuit, 42 is a detection circuit, 43 is a low pass filter, 44 is a waveform shaping circuit, 45 is an exclusive OR circuit, 46 is the first NAND circuit, 47 and 48 are the first NAND circuit.
1NOT circuit and 2nd NOT circuit, 49 is the 2nd NAND
circuit, 50 is the first AND circuit, 51 is an integration circuit, 5
Reference numeral 2 denotes a judgment circuit having a judgment level that determines the range of phase matching; 53 a second AND circuit; 54 a flicker circuit; 55 a low frequency oscillation circuit; This is a driver circuit that drives the device 21.

The phase detection circuits A and B convert the AC waveforms of the charging voltages of the two AC transmission and distribution lines whose phases are to be compared into two rectangular wave voltage signals corresponding to their positive or negative half cycles, respectively. It is characterized in that two rectangular wave voltage signals are applied to an exclusive OR circuit, and the phase difference is detected from the average value of the output.

Next, the above-mentioned operation of the phase detectors 4 and 5 will be explained with respect to the phase detector circuits A and B.

Connect the hanging fitting 9 of the phase detector 4 on the transmitting side to the electric wires 3a, 3.
In the suspended state of either b or 3c, the electric wire 3
A, 3b, and 3c are connected to the ground via the hanging fitting 9, the detection capacitors 22, 23, the conductor 17', and the stray capacitance 24, as shown in FIG. 8 and FIG. 9A. It is flowing to. The first level detection circuit 25 outputs a charging state detection signal when the voltage across the detection capacitor 23 becomes larger than the detection level _V1 . This output causes the switching circuit 27 to generate an ON output. Furthermore, this
Once the charging state is detected, the ON output continues for a fixed period of time, for example, 2 to 3 seconds. this
The ON output operates the flicker circuit 32 and the driver circuit 33, and the indicator light 19 starts blinking. At the same time, the second level detection circuit 26 outputs a high level output when the voltage across the detection capacitors 22 and 23 becomes larger than the detection level _V2 , and converts the sine waveform A of the charging voltage of the wire into a rectangular shape. The low frequency oscillator 28 outputs a low frequency signal to the mixing circuit 30 only during the high level period. Here, switching circuit 2
7 outputs ON, the high frequency oscillation circuit 29 performs oscillation and outputs it to the mixing circuit 30, so the mixing circuit 30 generates a high frequency signal modulated by the low frequency signal only during the high level period of the rectangular wave. The signal is output to the amplifier 31 and is emitted from the transmitting antenna 17. When the state of charge is detected in this way, a high frequency wave on which a rectangular wave C which is a phase signal is superimposed as a low frequency signal is transmitted from the transmitting antenna 17, and the blinking of the indicator light 19 indicates that the transmission is in progress. You can check it.

Further, the phase detection circuit B of the phase detector on the receiving side performs the phase detection operation as follows.

Connect the hanging fitting 10 of the receiving side phase detector B to the electric wires 3a', 3.
When the electric wire is suspended from either terminal b' or 3c', when the electric wire is in a charged state, the first level detection circuit 37 and the switching circuit 39 detect the charging state by the same operation as described above, and change the ON output to the first level. Output to 2AND circuit 53. The second level detection circuit 38 also operates in the same manner as described above, converting the sinusoidal waveform (b) of the charging voltage of the electric wire into a rectangular wave (d) and outputting the same. Further, the transmitting side radio waves emitted from the transmitting antenna 17 are received by the receiving antenna 18, and this high frequency wave is transmitted to a frequency conversion circuit 40, an intermediate frequency amplification circuit 41, a detection circuit 42, a low pass filter 43, and a waveform shaping circuit 44. The rectangular wave C generated by the second level detection circuit 26 in the phase detector 4 on the transmitting side is extracted.

The rectangular wave C extracted in this way is
The square wave D output from the level detection circuit 38 is compared with the exclusive OR circuit 45 in the following manner, and it is determined whether the phases of the charging voltages of the two wires match or do not match.

First, a case where the phases match will be explained. In this case, as shown in FIG. 8, the phases of both rectangular waves C and D completely match. Therefore, the output of the first NAND circuit 46 receiving the inputs of both rectangular waves C and D is as shown in FIG. 8E. Also, both rectangular waves C,
The signals obtained by inverting D in the first NOT circuit 47 and the second NOT circuit 48 are as shown in FIG. Be like Chi. Then, the output obtained by inputting the outputs E and J to the first AND circuit 50 becomes a zero level output over the entire period, as shown in FIG. 8R. Therefore, the output obtained by inputting this to the integrating circuit 51 is also at zero level, and since this is lower than the set level, the determination circuit 52 outputs a low level mismatch output. Therefore, the second AND circuit 5
3, even if the switching circuit 39 is outputting a high level to detect charging, it outputs a low level and does not operate the flicker circuit 54. Therefore, indicator 2
0 goes out and the sound generator 21 does not operate.

On the other hand, if the rectangular waves A and B are out of phase as shown in FIG. 9, the following mismatch detection operation is performed.

When both wires to be phase-compared are in a charged state, rectangular waves C and D generated from charging voltages A and B are output from the waveform shaping circuit 44 and the second level detection circuit 38 by the same operation as described above. Output. These rectangular waves C and D are sent to the first NAND circuit 46 and the
2NAND circuit 49, first and second NOT circuit 47,
48. When input to the exclusive OR circuit 45 composed of the first AND circuit 50, the output shown in FIG. 9 is obtained by the above-mentioned logical operation. In FIG. 9, this output L is a portion where the high level portions of the two types of rectangular waves C and D do not overlap, that is, a portion where the phases are shifted. This output signal is input to an integrator circuit 51 and averaged, and its level is further compared with a judgment level in a judgment circuit 52. If the size of the phase shift exceeds a certain amount, the judgment circuit 52 goes to a high level to detect a mismatch. Outputs level. For this reason,
The output of the 2AND circuit 53 remains at a high level, and the indicator light 20 and sound generator 21 continue to operate due to the operations of the flicker circuit 54, low frequency oscillator 55, and driver circuit 56, indicating a phase mismatch.

In the receiving side phase detector 5 of the present invention, the two types of rectangular waves C and D are input to the exclusive OR circuit 45 for phase comparison. It can be detected linearly within the range. Therefore, the detection accuracy is high, and the determination level of whether the phases match or do not match in the determination circuit 52 can be easily and accurately set.

Further, the exclusive OR circuit 45 of the above embodiment is not limited to the above configuration, and can be constructed from any electronic component such as an exclusive OR circuit using an IC.

As explained above, according to the present invention, when an AC power transmission/distribution line is being charged, phase detection is performed by obtaining a rectangular wave corresponding to the positive or negative half cycle of the AC waveform of the charging voltage. In the device, the phase signal of the charging voltage of the wire to be connected is extracted at a level close to zero potential that is set separately from the level for detecting the presence or absence of charging, and converted into a rectangular wave. Since the signal is transmitted from the transmitting side to the receiving side phase detector, there is no need for wiring such as cables, which facilitates the phase checking operation and increases safety. In addition, as a method of displaying charging status and phase match/mismatch, the transmitting side phase detector uses an indicator light to indicate that charging is in progress, and the receiving side phase detector displays when charging is in progress and the phases do not match. The indicator lamp flashes and the sound generator emits a sound, and when the phases match during charging, both the indicator light and the sound generator are stopped, so both electric wires to be connected are both charging, and It is possible to reliably determine that they are in the same phase.

Then, phase comparison is performed using an exclusive OR circuit, the output is averaged by an integrator circuit, and the average value is input to a determination circuit to determine whether the phases match or disagree. is obtained. In other words, the output of the integrating circuit is
Constant value (e.g. 5V) from OV for a range of 180°
A linear proportional relationship can be obtained for voltage values in the range of , and the determination level for determining phase mismatch can be easily and accurately set in the determination circuit.

[Brief explanation of the drawing]

Figures 1, 4 and 5 are diagrams showing how the phase detector of the present invention is used, Figure 2 is a front view of the phase detector on the transmitting side, and Figure 3 is a front view of the phase detector on the receiving side. Front view, Figure 6 is the phase detection circuit diagram of the transmitting side phase detector, Figure 7 is the phase detection circuit diagram of the receiving side phase detector, and Figure 8 is the phase detection circuit when the phases match. Figure 9 is a waveform diagram of each part of the phase detection circuit when the phases do not match, and Figure 10 shows the relationship between the two detection levels in the detection section and the rectangular wave whose waveform has been converted. FIG. 4... Phase detector on the transmitting side, 5... Phase detector on the receiving side, 3a, 3b, 3c, 3a', 3b', 3c'... Electric wire, 9, 10... Hanging fitting, 17... Transmitting Antenna, 18... Receiving antenna, 19, 20... Indicator light, 21... Sound generator, 25, 37... First level detection circuit, 26, 38... Second level detection circuit, 45... Exclusive logical OR circuit, A... Phase detection circuit on the transmitting side, B... Phase detection circuit on the receiving side, a, b...
Detection unit.

Claims (1)

[Scope of Claim for Utility Model Registration] Hanging fittings for hanging from electric wires, a first level detection circuit that detects whether or not the electric wire is in a charged state based on the voltage led to the hanging fittings, a second level detection circuit that converts the alternating current waveform of the charging voltage into a rectangular wave that is a phase signal; a display section that displays the charging state of the wire on an indicator light; and a radio wave that uses the rectangular wave as a phase signal when the wire is in the charging state. a phase detector on the transmitting side, which is equipped with a transmitter that emits from the transmitting antenna mounted on the wire; a hanging fitting for hanging the electric wire; 1 level detection circuit, a 2nd level detection circuit that converts the alternating current waveform of the charging voltage into a rectangular wave as a phase signal using the voltage led to the hanging fitting, and a sound generator that blinks an indicator light when the wire is in a charging state. A display section that generates sound, a receiving section that receives radio waves emitted from a phase detector on the transmitting side with a receiving antenna and extracts the rectangular wave on the transmitting side, and extracts the discrepancy between the rectangular wave on the receiving side and the rectangular wave on the transmitting side. The phase shift is detected by the average value of the output of the exclusive OR circuit and the exclusive OR circuit,
A phase detector consisting of a phase detector on the receiving side, which is equipped with an indicator light on the display section and a determination circuit that stops the operation of the sound generator when the phases are the same.