JP2005164463A - Voltage/current measuring device for distribution equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable package measurement, surface position measurement or the like of the voltage/current at an optional portion in distribution equipment such as a distribution line. <P>SOLUTION: In a voltage/current sensor part, a current measuring Hall element 1 and a voltage measuring Pockels element 2 are arranged close relative to the distribution line L on its coating member surface. A current supply source 3 supplies a current for generating a current detection signal in the Hall element. An optical fiber cable 4 transmits a light input and a light signal output relative to the Pockels element. A light-voltage converter 5 acquires a voltage signal output measured by the light input output of a fixed light quantity to the Pockels element. An A/D converter 6 converts a current detection signal and a voltage detection signal into digital signals. A display part 7 outputs measuring signals of the current and the voltage. The Hall element and the Pockels element are stored in a grip mechanism arranged close to the distribution line, dismantled from the distribution line, and slidable along the distribution line. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for measuring voltage / current of distribution equipment such as distribution lines constituting a distribution system.

  In the distribution system, long-distance distribution lines are laid from substations to general consumers, and distribution facilities such as section switches, branch switches, and step-down transformers are inserted between them.

  In the protective relay system of the distribution system, voltage and current measuring instruments are installed at appropriate line spacing positions such as the above switch positions, etc., and the upstream side of these measuring instruments such as measuring voltage and current and substations, etc. By comparing the measured voltage and current with each other, overvoltage and overcurrent due to distribution line ground faults and short circuit accidents are detected. When an accident is detected, the section switch is opened and closed to enable system protection and disconnection of the accident section ( For example, see Patent Document 1).

  As shown in FIG. 5A, the current measuring instrument engages a current transformer (CT) 2 with the distribution line 1, and converts the secondary current output of the current transformer 2 into a voltage signal. The A / D converter 2 converts it into a digital quantity, displays it on a display device 3 such as a multimeter, and takes it in as a current measurement input to the protective relay circuit side.

In addition, as shown in FIG. 5B, the voltage measuring instrument connects a transformer 4 between the lines of the distribution line 1, and the secondary voltage output of the transformer 4 is digitally converted by the A / D converter 5. It is converted into a quantity, displayed on a display device 6 such as a multimeter, and further taken in as a voltage measurement input to the protective relay circuit side.
Japanese Patent Laid-Open No. 11-178200

  As described above, the conventional voltage / current measuring instrument installed in the distribution system is only a single-function machine that measures the voltage or current at the position of the distribution line in which they are installed. Moreover, since the conventional voltage / current measuring instrument is fixed at the installation position, it can only measure at a point position and cannot measure at a wide range of surface positions.

  For these reasons, with conventional voltage / current measuring instruments, the position of the overvoltage and overcurrent generation in the distribution system in the distribution system alone is on the high voltage side / low voltage side of the distribution system. Furthermore, it was not possible to identify which distribution equipment caused the problem.

  An object of the present invention is to provide a voltage / current measuring device for power distribution equipment that can solve the above-described problems and obtain the effects described later.

  In order to solve the above-mentioned problems, the present invention configures a current sensor with a Hall element, configures a voltage sensor with a Pockels element, and arranges both sensors in close proximity to an arbitrary part of a distribution line to be measured. The voltage / current sensor can be removed and slid, and has the following configuration.

(1) A current detection sensor using a Hall element and a voltage detection sensor using a Pockels element are arranged close to a part of a distribution line to be measured for voltage and current, and a detection signal for the voltage and current of the part is obtained. Voltage / current sensor,
A measurement signal processing unit connected to the voltage / current sensor unit through a signal line and converting the detection signals of the voltage sensor and the current sensor into digital signals, respectively, is provided.

  (2) The voltage / current sensor unit incorporates a current sensor using the Hall element in one of a pair of gripping parts whose joints serve as rotation support points, and a voltage using the Pockels element in the other. The Hall element and the Pockels element can be arranged close to the distribution line at the gripping part by holding a sensor and holding any part of the distribution line to be measured by the pair of gripping parts, and the pair of gripping parts And a gripping mechanism that is slidable along the distribution line.

  As described above, according to the present invention, the voltage / current sensor includes a Hall element as a current sensor, a Pockels element as a voltage sensor, and both sensors are bundled at any part of a distribution line to be measured. Therefore, the following effects can be obtained.

  (1) The current and voltage of the measurement site of the distribution line to be measured can be simultaneously measured.

  (2) The function can be expanded from the point position measurement to the surface position measurement by arranging and removing the distribution line at any measurement site.

  (3) The disconnection location can be determined by sliding along the distribution line.

  (4) Measurement can be performed with the voltage / current sensor portion being in non-contact with the distribution line, and the measurement work is simplified.

  (5) By replacing the voltage / current sensor with a Hall element or Pockels element with different sensitivities, it can be used to measure the high and low voltage sides of the distribution line and the distribution equipment itself such as a step-down transformer.

  (6) Since the detection signal is digitally processed, dynamic measurement can be performed in combination with the sampling measuring instrument.

  (7) A portable or in-vehicle voltage / current measuring device can be realized.

  FIG. 1 is a configuration diagram of a voltage / current measuring apparatus showing an embodiment of the present invention. This embodiment includes a voltage / current sensor unit that detects a voltage / current of a distribution facility such as a distribution line to be measured, and a measurement signal processing unit that obtains a voltage / current measurement signal from the detection signal.

  The voltage / current sensor unit is configured such that the current measuring Hall element 1 and the voltage measuring Pockels element 2 can be disposed close to the distribution member L as an example of the distribution facility of the distribution system.

  Current measurement using the Hall element 1 will be described in principle with reference to FIG. When a current I is passed through the Hall element 1 made of a semiconductor and a magnetic field (magnetic flux B) is applied in a direction perpendicular to the current, a Hall voltage V is generated in directions orthogonal to the direction of the current I and the direction of the magnetic flux B, respectively. (This phenomenon is called the Hall effect). The Hall element 1 utilizing this Hall effect is arranged in a magnetic field (magnetic flux B) having a strength corresponding to the current of the distribution line to be measured for current, and is distributed to the Hall voltage V with a constant current I flowing. A voltage output corresponding to the wire current can be obtained.

  The Pockels element 2 is called an electro-optic effect element. When an electric field is applied to the electro-optic crystal, its refractive index changes, and this refractive index change is proportional to the applied electric field E (this phenomenon is called the Pockels effect). . The Pockels element 2 using the Pockels effect is arranged in an electric field having a strength corresponding to the voltage of the distribution line to be measured for voltage, and the difference in the refractive index of light when the Pockels element 2 is transmitted through the polarizing plate Can be obtained, and a voltage output obtained by light-voltage conversion of the light output can be obtained.

  Next, the measurement signal processing unit in this embodiment will be described. In FIG. 1, the current supply source 3 supplies a constant current I to the Hall element 1, thereby causing the Hall element 1 to generate a current detection signal due to the Hall effect. The optical fiber cable 4 transmits an optical input to the Pockels element 2 and an optical signal output in which the refractive index from the Pockels element 2 is changed. The light-voltage converter 5 receives a light output of a constant light amount to the optical fiber cable 4 and receives light through the optical fiber cable 4 to obtain a voltage signal output corresponding to the light reception amount.

  The A / D converter 6 uses the current detection signal from the Hall element 1 and the voltage detection signal of the Pockels element 2 that is output from the light-voltage converter 5 as input signals, and converts each of them into a digital signal in a time-sharing manner. .

  The display unit 7 includes a personal computer, a multimeter, a synchroscope, and the like. The display unit 7 captures a current and voltage detection signal (digital signal) that are output from the A / D converter 6, and displays the current current corresponding to the digital signal. Displays and outputs voltage measurement signals (current / voltage values, phase, waveform, power factor, etc.). The display unit 7 can display numerical values, waveforms, and phases on a personal computer, a shake of a pointer on a multimeter, and a waveform on a synchroscope.

  According to the voltage / current measuring device having the above-described configuration, the Hall element 1 and the Pockels element 2 are arranged close to the distribution line L to be measured, so that the current and voltage measurement outputs of the distribution line L can be collectively collected. Can be obtained at the same time.

  FIG. 3 shows that the Hall element 1 and Pockels element 2 of FIG. 1 can be easily placed close to the distribution line L to be measured for current and voltage, and can be easily removed from the distribution line L. A gripping mechanism of a voltage / current sensor unit that can be slid along is shown. The gripping tool 11 is made of, for example, an epoxy resin having high insulation performance, and includes a pair of electric wire gripping portions 11B and 11C having the joint portion 11A as a rotation support point of each other. Each of the grip portions 11B and 11C has a semi-cylindrical cross section, and has a semi-cylindrical recess that can grip the distribution line L on the inner peripheral side.

  In the holding part 11B, the Hall element 1 is embedded in the radial direction, and a current supply lead wire from the current supply source 3 to the Hall element 1 and a voltage output lead wire from the Hall element 1 to the A / D converter 6 are embedded. Is connected.

  In the holding portion 11C, the Pockels element 2 is embedded in a direction orthogonal to the radial direction, and an optical fiber cable for introducing light from the light-voltage converter 5 to the Pockels element 2 and light from the Pockels element 2 are used. -An optical fiber cable for leading out the light to the voltage converter 5 is connected.

  According to the configuration of the voltage / current sensor section described above, the gripping sections 11B and 11C are opened to each other at the joint section 11A, and are closed with the distribution line L being positioned in the recess of the inner peripheral section. The distribution line L can be gripped by rotating in the direction. In this gripping state, for example, the gripping portions 11B and 11C can be held in surface contact with each other by a lock or a locking jig.

  From the above, in the present embodiment, the voltage / current sensor unit (1, 2, 11) grips the distribution line L located at an arbitrary measurement point, and the measurement processing unit (3-7) is connected thereto. Alternatively, by connecting, voltage / current measurement signals (current / voltage values, phase, waveform, power factor, etc.) of the distribution line L can be obtained simultaneously.

  Further, the voltage / current sensor unit can be measured in a non-contact manner with respect to the distribution line, and the work of cutting off the distribution line and connecting the terminals of the measuring instrument directly becomes unnecessary.

  In addition, since the voltage / current sensor unit can ensure high insulation performance with a non-contact method, it is possible to measure either the high-voltage side or the low-voltage side of the distribution line by replacing it with a Hall element or Pockels element with a different sensitivity. It can also be applied to. In addition, the voltage and current of the distribution equipment itself such as a step-down transformer can be measured.

  Further, since the measurement processing unit adopts a digital processing method by A / D converting the detection signal, it can be used in combination with the sampling measuring instrument to perform dynamic measurement. Furthermore, it is possible to expand the functions of the overcurrent detection relay and the overvoltage detection relay.

  In addition, since the voltage / current sensor unit is a mechanism that can be attached to any position of the distribution line, the distribution line position (measurement point) can be arbitrarily changed, and measurement by surface measurement can be performed from the conventional point measurement.

  For example, as shown in FIG. 4 as an example of a dynamic measurement method, a measurement signal processing unit composed of a personal computer or the like is installed at the initial arrangement position A of the voltage / current sensor unit and connected to the sensor unit. The voltage / current measurement signal during the sliding can be continuously obtained by sliding from the position A to the position B along the distribution line L. By this sliding and continuous measurement, for example, when the distribution line is disconnected between the positions A to B, it is possible to determine the position where the measurement voltage is rapidly decreased as the disconnection location.

  In addition, since the voltage / current sensor unit can be mounted at any position on the distribution line and a measurement signal processing unit such as a personal computer is connected to this, a portable or in-vehicle voltage / current measurement device can be realized, It can be used as a device for searching for disconnection points of distribution lines and distribution facilities. In this case, a signal line connecting the voltage / current sensor unit and the measurement signal processing unit is built in an insulation rod, etc., and the measurement operator attaches the voltage / current sensor unit to the measurement site by operating the insulation rod, and on the ground side A measurement signal can be obtained in a portable or vehicle-mounted measurement signal processing unit.

1 is a configuration diagram of a voltage / current measuring device showing an embodiment of the present invention. An explanatory view of the principle of the Hall effect. The holding mechanism figure in an embodiment. The example of the dynamic measurement method in embodiment. A conventional voltage / current measurement circuit diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hall element 2 Pockels element 3 Current supply source 4 Optical fiber cable 5 Optical-voltage converter 6 A / D converter 7 Display part 11 Holding tool 11A Joint part 11B, 11C Electric wire holding part

Claims (2)

A voltage detection sensor that uses a Hall element and a voltage detection sensor that uses a Pockels element in close proximity to the distribution line to be measured for voltage and current, and obtains the voltage and current detection signals for that area. A sensor unit;
The voltage / current sensor unit is connected to the voltage / current sensor unit by a signal line, and includes a measurement signal processing unit that converts the detection signals of the voltage sensor and the current sensor into digital signals and displays them. Current measuring device. The voltage / current sensor unit has a built-in current sensor using the Hall element in one of a pair of gripping parts whose joints serve as rotation support points, and a built-in voltage sensor using the Pockels element in the other. The Hall element and the Pockels element can be placed close to the distribution line at the gripping part by gripping any part of the distribution line to be measured with the pair of gripping parts, and the pair of gripping parts are connected to the distribution line. The voltage / current measuring device for power distribution equipment according to claim 1, further comprising a gripping mechanism that is slidable along the power distribution line.

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