JPS63273068A - Optical electric field meter - Google Patents

Abstract

PURPOSE:To improve a measuring accuracy by detecting a field strength by light and using an optical fiber for a power transmission line. CONSTITUTION:A field sensor 14 mounted on the insulating rod 12 of a tripod 11 is arranged in a position just below a high voltage portion, such as a power transmission line, and at about 1m aboveground height. The sensor 14 optically detects a field strength just below the high voltage portion. A voltage sensor 21 composed of optical parts consisting of a polarizer 17, a quarter-wave plate 18, electro-optical crystal 19 and an analyzer 20 is used as the sensor 14. The optical quantity of the sensor 14 is supplied to an electric field meter 15 via an optical fiber bundle 16, converted to an electric quantity by O/E and E/O converters and indicated by a meter so that a field strength can be directly read. Thus, the measuring accuracy of the field strength can be improved.

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention uses an optical electric field meter, more specifically, a sensor formed by combining an electro-optic crystal element and an optical component, and uses it to measure power transmission lines and high-voltage equipment directly below. This invention relates to an optical electric field meter for measuring electric field strength.

<Prior Art> It is necessary to know the electric field strength inside a substation or around an overhead power transmission line for reasons such as safety or equipment layout design, and it is extremely important to know the value of the electric field strength.

Especially when 500KV power transmission is started, for example, 5 people
When passing under a 00KV power line with an umbrella, a part of the body of a caterpillar may come into contact with the metal handle, or a 500KV
If you touch a metal part of a car, building, fence, etc. that is directly under a power transmission line, the electric charge generated by electrostatic induction will cause a current to flow through your body, which is extremely dangerous.

Therefore, it is necessary to measure the electric field strength E (V/cm) directly under the power transmission line.

Conventionally, a measuring device used to measure the electric field strength directly under a power transmission line has a metal disk 3 with a diameter of 1 m attached to the upper end of an insulating column 2 supported by an insulator 1, as shown in FIG. The structure is such that the metal disk 3 and the high voltage terminal 5 of the static N-pressure gauge 4 are connected by a lead wire 6 made of copper wire, and the ground terminal 7 is grounded.

The above measuring device reads the potential difference generated by a high voltage section such as the power transmission 1jA on the metal disk 3 with an electrostatic voltmeter 4, and calculates the electric field strength by multiplying the read value by a predetermined partial pressure ratio.

By the way, the formula for calculating the electric field strength is: C1: Capacitance of the metal disk, lead wire, and voltmeter C2: Capacitance of the lead wire and voltmeter V: Indicated value of the voltmeter Problems> By the way, the above measuring device uses a metal disk with a diameter of 1 TrL as an electrode, which makes it bulky and inconvenient to handle.Also, since it uses a W4 wire as a lead wire, the electric field strength and voltage is affected by induction, the measurement value is inaccurate,
Moreover, the electric field strength cannot be determined by direct reading from a voltmeter and must be calculated, so there is a problem in that it is time-consuming to measure.

<Purpose of the Invention> The present invention was made to solve the above-mentioned problems, and provides an optical electric field meter that can safely measure electric field strength without being affected by induction and is convenient to handle. The purpose is to

Means for Solving the Problems> In order to solve the above problems, the present invention uses an insulated electric field sensor that detects the voltage generated between two metal plate electrodes facing each other using an electro-optic crystal element. It is mounted on a support leg, and has a structure in which the electric field sensor and an electric field meter equipped with an optical transmitting/receiving circuit are connected by an optical fiber.

<Operation> An electric field sensor mounted on an insulated support leg is placed directly under the power transmission line, and the previously detected electric field is sent to the electric field meter via an optical fiber.The electric field meter converts the optical quantity into an electrical quantity, Display the intensity so that it can be connected directly.

<Embodiments> Examples of the present invention will be described below with reference to FIGS. 1 to 5 of the accompanying drawings.
This will be explained based on the diagram.

As shown in Fig. 1, the optical electric field meter has an insulating rod 12 on a tripod 11
are erected to form an insulating support leg 13, an optical electric field sensor 14 is attached to the upper end of the insulating rod 12, and the electric field sensor 14 and an electric field meter 15 equipped with an optical transmission/reception circuit are connected with an optical fiber 16. has been done.

The electric field sensor 14 has a polarizer 17 as shown in FIG.
．． A voltage sensor 21 is constructed using optical components such as a 174 wavelength plate 18, an electro-optic crystal 19, and an analyzer 20, and these optical components are housed in a case, and the entire body is housed in a resin container.

Each of the optical components, the electro-optic crystal 19, and the case are formed using an insulator that hardly disturbs the electric field distribution,
The electro-optic crystal 19 has a Pockels effect structure in which the voltage generated between two opposed metal flat plate electrodes is detected by lead wires extending from both sides of the electro-optic crystal element.

FIG. 4 shows the principle of the above voltage sensor, and shows the light source 22.
The light from is guided by an optical fiber and enters the polarizer 17,
The light becomes linearly polarized, changes to circularly polarized light after passing through the 174-wave plate 18, and enters the electro-optic crystal 19.

When an electric field is applied to the electro-optic crystal 19, a difference is created in the refractive index in a direction perpendicular to the optical axis, and the circularly polarized light becomes elliptically polarized light.

When this light passes through the analyzer 20, the incident light is outputted in the form of intensity modulation.

To attach the electric field sensor 14 to the upper end of the insulating rod 12, as shown in FIG.
3, and fix the joint 23 so as to be adjustable in the circumferential direction with the set screw 25 using the fixing ring spacer 24. At the same time, the electric field sensor 14 attached to the upper end of the variable joint 23 can be adjusted in the vertical direction. by means of a variable set screw 26;
The structure allows the height and horizontal direction of the electric field sensor 14 to be changed freely.

The optical fiber 16 connecting the electric field sensor 14 and the electric field meter 15 uses a two-core optical fiber coat or a two-core optical fiber cable, and is connected to the electric field meter 15 using an optical connector. O/E is an optical transmitter/receiver circuit.

Consists of an E/O converter and a meter, the electric field strength is Vrm
It is displayed in units of s4, and a DC voltage proportional to the electric field strength is output for use in a recorder.

The optical electric field meter of the present invention has the above-mentioned configuration, and the electric field sensor 14 mounted on the insulating rod 12 of 3 [1111] is placed at a height of 1 m above the ground directly under a high voltage section such as a power transmission line. The electric field sensor 14 detects the electric field strength immediately below the high voltage section in advance.

The optical quantity of the electric field sensor 14 is supplied to the electric field meter 15 via the optical fiber 16, converted into an electrical quantity by the O/E1E/O converter, and displayed on the meter so that the electric field strength can be directly read.

<Effects> As described above, according to the present invention, the electric field strength is detected by light and an optical fiber is used for the transmission path, so the measurement signal electric field strength can be measured without induction, and the accuracy of measuring the electric field strength is greatly improved. At the same time, by extending the optical fiber,
The electric field meter can be read at a location away from the detection part, allowing safe measurements.

Furthermore, since the electric field detection portion and the transmission path are optical, the device can be made smaller and lighter, making it convenient to carry.

[Brief explanation of the drawing]

Fig. 1 is a front view of the optical electric field meter according to the present invention, Fig. 2 is an enlarged front view of the electric field sensor part in the same as above, Fig. 3 is a front view showing the mounting part of the electric field sensor, and Fig. 4 is a voltage sensor. FIG. 5 is an explanatory diagram showing the operating principle of the same, and FIG. 6 is an explanatory diagram showing a conventional measuring device. 11-...Tripod 12...Insulating rod 13
... Electric field sensor 15 ... Electric field meter 1
6... Optical fiber applicant patent attorney Kazu 1) Showa 1, 2, 3, 5

Claims (4)

[Claims] (1) An electric field sensor that detects the voltage generated between two metal flat electrodes facing each other using an electro-optic crystal element is mounted on an insulated support leg, and an electric field meter equipped with the electric field sensor and an optical transmitting/receiving circuit is installed. Optical electric field meter connected with optical fiber. (2) The electric field sensor combines an electro-optic crystal element with Pockels effect and optical components, and molds the entire body in resin.
The optical electric field meter according to claim 1, which is formed by housing this in an insulating case. (3) The optical fiber that connects the electric field sensor and the electric field meter is a two-core optical fiber cord or a two-core optical fiber cable, and this optical fiber connects the electric field meter to the electric field meter using an optical connector for O/E, E/ The optical electric field meter according to claim 1, which is combined with an O converter. (4) The optical electric field meter according to claim 1, wherein the electric field sensor is mounted on an insulating support leg so that its horizontal direction and vertical height position can be adjusted.