JPH0458162A - High-voltage measuring instrument and high-voltage phase difference measuring instrument - Google Patents

Abstract

PURPOSE:To easily measure the voltage of a high-voltage part at low cost by receiving the output of a transmitting means which sends the output of a voltage sensor to an earth-potential side and displaying the voltage of the high-voltage part. CONSTITUTION:A 1st and a 2nd insulating rod 3 which have voltage sensors 2 at their head parts are brought into contact with high-voltage parts at two places of power transmission lines 1a and 1b, etc., whose phase difference is to be measured. Then ON-OFF signals which match the high voltage phase positions of the high-voltage parts are outputted by the voltage sensors 2 of the 1st and 2nd insulating rods 3 and sent to the earth-potential side by transmitting means 4 which use, for example, optical fibers. A phase difference measuring instrument 20 measures the phase difference of the outputs obtained by the transmitting means 4 to display the voltage phase difference between the two places. Consequently, the specific voltage phase difference can easily be measured at low cost.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a high voltage measuring device that easily measures the voltage of a high voltage section, and a high voltage phase difference measurement device that detects the phase difference between two high voltage sections. It is related to the device.

[Prior Art] Conventionally, methods for measuring voltage at high voltage sections such as overhead power transmission lines or substation busbars include (a) inserting a voltage divider between the energized object and the ground and measuring the divided voltage output; (b)
Attach a voltage sensor to the high voltage section and convert its output to A/D
(There are technologies that perform analog/digital conversion or V/F (voltage/frequency) conversion and transmit it to the ground potential section optically or wirelessly.

In addition, as a method for detecting the phase difference between two places in a high voltage section, (C) detects the power line voltage with a sensor that is in contact with it, converts this information into A/D or V/F, and converts it into an optical Alternatively, there is a technology that wirelessly transmits the data to the ground potential and compares the phase, or (d) as shown in Figure 9, the threshold is set near OV and the optical output is sent only when the power line voltage is higher than this.
ON-OFF signals corresponding to the positive and negative half waves are sent to the ground potential section using a simple sensor, and assuming that the sensor output signal has a pulse width of 180°, the sensor output signal A obtained from two points on the power transmission line, There is a technique that measures (180° - (A-B pulse width)) as a phase difference with respect to B.

E Problems to be Solved by the Invention] However, in the high voltage measuring method (a), there is a problem that the voltage divider requires a high withstand voltage and the device becomes large. Also,(
The high voltage measurement method (b) and the phase measurement method (C) have problems such as the sensor section being complicated, large in size, and costly. Furthermore, in the phase measurement method of (d), the actual ONN
There is a problem in that the pulse width of the -OFF signal is not exactly 180 degrees, but varies. That is, as shown in Fig. 10, the threshold value for binary conversion into ON-OFF signals is not Ov or varies, and therefore the pulse width of the phase output signal is 180° and the 9 phase difference is calculated. The measurement resulted in a large error.

An object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a high voltage measuring device that measures the voltage of a high voltage section at low cost and easily, and a high voltage phase difference measuring device that measures the phase difference at low cost and with high precision. It's about doing.

[Means for Solving the Problems] The high voltage measuring device of the present invention is attached to the head of an insulating rod, and when it comes into contact with a high voltage part, the pulse width changes depending on the voltage of the high voltage part. A voltage sensor that outputs an ON-OFF signal, a transmission means that transmits the output of the voltage sensor to the ground potential side, and a measurement display that receives the output from the transmission means and displays the voltage of the high voltage section. It has a configuration that includes: In this case, the voltage sensor includes a contact electrode that contacts the power transmission line, a floating electrode that is spaced apart from the contact electrode, and a voltage control element, a resistance element, and a field effect transistor that are connected in parallel between both electrodes. , the switching signal of the field effect transistor is turned ON-OF
It is preferable to include a light emitting element that outputs light as an F signal.

Next, the high-voltage phase difference measurement device of the present invention includes first and second insulating rods that are brought into contact with two high-voltage parts where the phase difference is to be measured, and a high-voltage phase difference measuring device that is attached to the head of each insulating rod. ON-, which is in contact with a voltage part and matches the voltage phase position of the high voltage part.
A voltage sensor that outputs an OFF signal, a pair of transmission means that transmits the output of each voltage sensor to the ground potential side, and a phase difference between the outputs from these transmission means is measured and the voltage phase difference between the two points is displayed. This configuration includes a phase difference measuring device. This phase difference measuring instrument includes a memory device that sequentially samples and stores the ON-OFF signals output from the two voltage sensors at regular intervals over one cycle of the power transmission line voltage, and a memory device that stores the ON-OFF signals that are the outputs of the two voltage sensors. It is preferable to have a configuration including a phase difference measuring device that detects a phase difference from the contents and a display device that displays the phase difference.

[Function] When the head of the insulating rod, that is, the voltage sensor, is brought into contact with a high voltage section such as an overhead power transmission line or substation busbar, the pulse width changes depending on the voltage of the high voltage section. −
An OFF signal is output from the voltage sensor, and the output of the voltage sensor is transmitted to the ground potential side by an optical fiber or wireless transmission means. The measurement display displays the voltage of the high voltage section from the pulse width of the transmitted output. Therefore, a predetermined voltage can be measured with a simple and inexpensive configuration in which a voltage sensor is attached to the head of an insulating rod.

Specifically, the above-mentioned voltage sensor connects a resistance element and a voltage control element in parallel between a contact electrode that contacts a power transmission line and a floating electrode that is spaced apart from the contact electrode. By switching the field effect transistor to operate the light emitting element and obtaining the optical output of the ON-OFF signal, the sensor section can be particularly simple, inexpensive, and compact.

Next, in the high-voltage phase difference measuring device, first and second insulating rods each having a voltage sensor on their head are brought into contact with two high-voltage parts such as a power transmission line whose phase difference is to be measured. The voltage sensors of the first and second insulating rods output an ON-OFF signal that matches the voltage phase position of the high voltage section, and the signal is transmitted to the ground potential side using optical or wireless transmission means.6 Phase difference measurement The device measures the phase difference of the outputs obtained from these transmission means and displays the voltage phase difference between the two points.

Therefore, a simple method with a voltage sensor attached to the head of an insulating rod,
A predetermined voltage phase difference measurement can be performed with an inexpensive configuration. The voltage sensor here can have the same configuration as the high voltage measuring device described above, and can be a simple, inexpensive, and small sensor.

In addition, in a configuration in which the phase difference measuring device is configured with a storage device 1, a phase difference measuring device, and a display device, the ON-OFF signals that are the outputs of the above-mentioned voltage sensors are sequentially sampled at regular intervals over one period and stored. be done. In other words, ON-
The waveform of the FF signal is temporarily stored in a storage device, and the phase difference is determined by a phase difference measuring device from the stored contents over one cycle. Therefore, even if the pulse width of the ON-OFF signal is not 180°, the phase difference can be measured with high accuracy.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 shows the basic configuration of a high voltage measuring device for an overhead power transmission line 1, which includes an insulating rod 3, a voltage sensor 2 attached to the head of the insulating rod 3, and information on the voltage sensor 2. It is composed of an optical fiber 4, which is a transmission means for transmitting the information to the base of the insulating rod 3, that is, to the ground potential side, and a measurement indicator 5, which is provided at the base of the insulating rod 3 and to which the optical fiber 4 is connected.

The insulating rod 3 and the optical fiber 4 are made of a material with good insulation properties that can sufficiently withstand the high voltage of the power transmission line 1, thereby allowing the voltage sensor 2 to be brought into contact with the power transmission line 1.

Voltage sensor 2 creates an optical ON-OFF signal with a pulse width corresponding to the voltage phase of power transmission line 1 and outputs it to optical fiber 4 . The measurement display 5 is a light ON-O from the optical fiber 4.
The voltage of the power transmission line 1 is measured and displayed based on the information of the FF signal.

FIG. 2 shows an example of the configuration of the voltage sensor 2.

7 is a contact hook as a contact electrode, and 8 is an induction electrode consisting of a floating electrode spaced apart from this contact electrode. A resistive element 6 of about IMΩ or less is connected between the contact hook 7 and the induction electrode 8, and the gate of a field effect transistor (FET) 10 is connected to the end of the resistor 6 on the contact hook 7 side. has been done. Furthermore, there are FETs at both ends of the resistance element 6.
A Zener diode 9 is provided as a protection voltage control element. The source of the field effect transistor 10 is connected to the inductive electrode 8, and the output circuit from the drain of the field effect transistor 10 to the inductive electrode 8 includes a current limiting resistor 139, a light emitting diode (LED) 11, and an LED.
A battery 12 serving as a driving power source is inserted.

When the contact hook 7 is hooked to the power transmission line 1, the induction electrode 8
A potential difference proportional to the resistance value and the power transmission line voltage is generated across the resistor 6 connected to the resistor 6 . This potential difference causes the field effect transistor 10 to be switched. In this case, the threshold value of the field effect transistor 10 is not “0”;
As shown in FIG. 3, it is on the positive half-wave side.

The voltage on transmission line 1 crosses this threshold, but
This crossing point changes on the time axis depending on the magnitude of the power transmission line voltage, as shown in FIG. That is, when the voltage is small, the distance between the two points where the positive half wave crosses the threshold level becomes narrower, and when the voltage is large, the distance between the two points where the positive half wave crosses the threshold level becomes narrower.
The 0 light emitting diode 11 whose distance between points is widened emits light only during the switching period in which the field effect transistor 10 is conductive.

Therefore, the output of the voltage sensor 2, that is, the light emitting diode 11
The pulse width of the ON-OFF binary light output from the third
As shown in the figure, it varies depending on the magnitude of the power transmission line voltage. The light emission output of the voltage sensor 2 is transmitted to the measurement display 5 on the ground side using the optical fiber 4 as a transmission path. The measurement display 5 is connected to the optical information from the optical fiber 4.
The length of the pulse width of the N period is measured, and the value converted to voltage is displayed.

FIG. 4 shows an example of the configuration of the measurement display 5.

The measurement display 5 includes an optical/electrical converter 14 that converts the output light of the optical fiber 4 into electricity, and a constant frequency (commercial frequency
60), an AND circuit 16 that takes the logical product of the optical/electrical converter 14 and the clock generator 15, and the output of the clock generator 15 is divided by 360 to generate a commercial frequency clock. Frequency divider 18 and frequency divider 1
8, and a display 19 that converts the count result into a voltage value and displays it.

As can be seen from the timing chart in Figure 5, AND
When the number of output pulses #116 is led to the counter 17 and counted for one period at the commercial frequency from the frequency divider 18, the output puzzle width of the optical/electrical converter 14 corresponding to the power transmission line voltage is measured. be able to. By measuring this pulse width, the power transmission line voltage can be displayed on the display 19.

The above-mentioned high voltage measuring device has a simple and inexpensive configuration using an insulating rod, and although the voltage sensor is also small, it can measure high voltage with sufficient accuracy for practical use.

Next, an embodiment of a high voltage phase measuring device that detects a phase difference between high voltage sections at a distance of 2 m will be described.

First, as shown in FIG. 6, there are two measuring devices a that have basically the same configuration as the high voltage measuring device shown in FIG.

It has b. That is, each measuring device a, b is equipped with a pair of voltage sensors 2 each supported by an insulating rod 3, and an optical fiber 4 which is an optical transmission means for transmitting information of the voltage sensor 2. Optical fiber 4 from measuring devices a and b
is connected to the phase measurement display 20 on the ground side.

The configuration of the voltage sensor 2 of each measuring device a, b is as explained in FIG. 6 phase difference measuring device 20 outputting to the optical fiber 4 of
measures and displays the phase difference between power transmission line 1 and power transmission line 2 based on optical information from both optical fibers 4.

As shown in FIG.
．． 22, a storage device 23 that stores the converted outputs, and a phase difference measuring device 24 that measures the phase difference from the stored waveforms.
and a display device 25 that displays measurement results.

As shown in FIG. 8, the storage device W23 has two locations (la,
The phase information SL, 32 from the ON-O
Whether the waveform of the FF signal is "ON" or "OFF" is sampled and stored. The sampling frequency is (power transmission line voltage frequency x 360). As a result, 360 phase sample values from each of the two locations are stored.

The phase difference measuring device 24 stores the 360 phase sample values stored in the storage device 23 as shown in FIG.

Divided into 90 pieces (each 90') as shown by ■, ■, ■, the number of sample values that are ON in each interval ■, ■, ■, ■ is m l, m2. m3. m4. Count. Then, the maximum number of these turned ON is m2 or m3
(section ■ or ■), the pulse width m = (m 1 + m 2 + m 3 + m 4) at around 1 of ■■■■
is determined, and the m/2nd ON position fK (center of the positive pulse) is set as the phase position P (FIG. 8(A)).

Also, the maximum number of sample values that are ON is ml or m4
(section ■ or ■), find the pulse width m in the order of the section ■■■■, add the number 180 corresponding to π/2 to the m / second ON digit fK (K + 180
> is the phase position P.

The above processing is performed on the phase information St and S2 from the 2flfi location to obtain the respective phases P1 and P2, and (P2-Pl)
is displayed on the display device 18. Thereby, the phase difference can be measured with high accuracy even if the phase information pulse is 180 degrees or less.

In the above embodiment, the phase information was transmitted through the optical fiber 4, but
Alternatively, voltage information or phase information can also be transmitted wirelessly. This increases ease of handling. However, when using wireless, there is an inconvenience that it will not work if there is a radio wave shield such as a transformer between the two voltage sensors.

[Effects of the Invention] As described above, according to the present invention, a predetermined voltage measurement in a high voltage section or a phase difference measurement at two locations can be easily performed with a simple and inexpensive configuration and with a small sensor unit configuration. can. especially,
In the case where the phase difference measuring instrument is equipped with a storage device to temporarily store ON-OFF waveforms, the pulse width of the ON-OFF signal is 1.
Even if the angle is not 80°, the phase difference can be measured with high accuracy.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the high voltage measuring device of the present invention, Fig. 2 is a diagram showing an example of the configuration of the voltage sensor, and Fig. 3 is a diagram showing the waveform of the power transmission line voltage and the output waveform of the voltage sensor. 4 is a diagram showing a configuration example of the measurement display in the high voltage measuring device of the present invention, FIG. 5 is a timing chart diagram showing the operation of the measurement display, and FIG. A configuration diagram showing an example of a high voltage phase difference measuring device, FIG. 7 is a diagram showing an example of the configuration of the phase difference measuring device, FIG. 8 is an explanatory diagram of phase difference measurement by the phase difference measuring device, and FIG. FIG. 10 is an explanatory diagram of a conventional phase difference measuring method, and FIG. 10 is a diagram showing the correspondence between the waveform of the sensor output and the waveform of the power transmission line voltage when the threshold value fluctuates. In the figure, 1.1a and lb are power transmission lines, 2 is a voltage sensor, 3 is an insulating rod, 4 is an optical fiber, 5 is a measurement display, 6 is a resistance element, 7 is a contact hook (contact electrode), and 8 is an induction Electrode (floating WIt pole), 9 is a Zener diode, 10 is a field effect transistor, 11 is a light emitting diode, 12 is a battery, 13
is a t current limiting resistor, 14 is an optical/optical converter, 15 is a clock generator, 16 is an AND circuit, 17 is a counter, 18 is a frequency divider, 19 is a display, 20 is a phase difference measuring device, 21° 2
2 is an optical/electrical converter, 23 is a storage device, 24 is a phase difference measuring device, and 25 is a display device. Patent Applicant Hitachi Cable Co., Ltd. Representative Patent Attorney Nobuo Kinutani 1; Power line 2; Voltage sensor section 3; Insulating rod 4; Optical fiber 5: Measurement display Figure 1 6: Resistance element 7: Contact hook ( Contact electrode) 8; Induction electrode 9; Sonia diode 1o: Field effect transistor/7 star 11: Light emitting diode 12; Battery 13: Current limiting resistor Fig. 2 20: Phase difference measuring instrument Fig. 6 Fig. 7 Fig. 4 Commercial One cycle of frequency Figure 5

Claims (1)

[Claims] 1. A voltage sensor that is attached to the head of an insulating rod and that outputs an ON-OFF signal that comes into contact with a high-voltage part and whose pulse width changes depending on the magnitude of the voltage of the high-voltage part. , a transmission means for transmitting the output of the voltage sensor to the ground potential side, and a measurement display that receives the output from the transmission means and displays the voltage of the high voltage section. Device. 2. The voltage sensor has a contact electrode that contacts a power transmission line;
A floating electrode separated from the contact electrode, a voltage control element, a resistance element, and a field effect transistor connected in parallel between the two electrodes, and a switching signal of the field effect transistor is optically output as the ON-OFF signal. 2. The high voltage measuring device according to claim 1, comprising a light emitting element. 3. First and second insulating rods are placed in contact with two high voltage parts where the phase difference is to be measured, and each insulating rod is attached to the head and is brought into contact with the high voltage part to measure the voltage phase of the high voltage part. A voltage sensor that outputs an ON-OFF signal that matches the position, a pair of transmission means that transmits the output of each voltage sensor to the ground potential side, and a phase difference between the outputs from these transmission means is measured and 1. A high voltage phase difference measuring device comprising: a phase difference measuring device that displays a voltage phase difference. 4. The phase difference measuring device includes a storage device that sequentially samples and stores the ON-OFF signals output from the two voltage sensors at regular intervals over one cycle of the power transmission line voltage, and one cycle of the power transmission line voltage. 4. The high-voltage phase difference measuring device according to claim 3, further comprising a phase difference measuring device for detecting a phase difference from stored contents over a period of time, and a display device for displaying the phase difference.