KR100206654B1 - A electronic mof based on optical sensors - Google Patents

Abstract

The present invention relates to an instrument transformer using an optoelectronic device, the instrument transformer includes a voltage divider (12) for dividing a high voltage on the high-voltage line (10), and a photoelectric converter for converting the voltage divided by the voltage divider (12) The phototransformer 14 having the Kells effect, the photovoltaic device 22 having a Faraday effect of reducing the voltage to a constant level by photoelectrically converting a large current flowing on the high voltage line 10, 14 and a light source driver circuit 16 and 24 for driving the optical variable current element 22, and a light receiving element driver circuit for detecting the voltage / current shifted by the optical transformer element 14 and the optical variable element 22 ( 18 and 26, and a signal processing circuit 20 and 28 for processing the voltage signal and the current signal to process the voltage signal corresponding to the voltage signal and the current level for power quantity measurement.

Description

Instrument transformer using optoelectronic device

1 is a block diagram showing the transformer of the instrument using the photoelectric device according to the present invention.

FIG. 2 is a diagram for explaining the configuration of the phototransformer shown in FIG.

FIG. 3 is a diagram for explaining the configuration of the optical variable current device shown in FIG.

4 is a diagram showing the configuration of a light source driving circuit for the configuration of the light source shown in FIG. 2 and FIG.

5 is a diagram showing an example of the configuration of a light receiving element driving circuit and a signal processing circuit shown in FIG.

FIG. 6 is a view showing a state in which the phototransformer and the photoconversion device shown in FIG. 1 are installed in the insulator.

* Explanation of symbols for main parts of the drawings

10: high voltage line 12: voltage divider

14 optical transformer 16 light source driving circuit

18: light receiving element driving circuit 20: signal processing circuit

22: optical current conversion element 24: light source driving circuit

26: light receiving element driving circuit 28: signal processing circuit

30, 40: light source 31, 41: polarizer

33, 42: optical modulator 34, 44: analyzer

35, 45: light receiving element 120: insulator

121: busbar

The present invention relates to a metering out fit (MOF) using an optoelectronic device, and more particularly, a light that proportionally denatures a high voltage / large current flowing in a high voltage line to a low voltage / small current suitable for metering by a photoelectric conversion element. The present invention relates to an instrument transformer using an optoelectronic device having a transformer element and a photocurrent element.

In general, the received electric power is transmitted from a power plant to a distribution transformer installed near a center of load through a high voltage distribution line, and supplied to a plurality of consumers through a low voltage distribution line while being stepped down to a certain level of voltage in the transformer. do.

However, according to the power transmission and distribution system, in order to transmit or distribute electricity generated in a power plant to a customer, it is via a plurality of power transmission / distribution system systems, and in the substation, the high voltage electricity is transformed to a constant level so that subsequent distribution lines Feeding through the furnace.

Therefore, in order to operate the substation, it is necessary to measure the voltage or current of the power system to measure the power used, and to measure the voltage or current to protect the power system and equipment, but the high voltage / high current electricity is directly As a means for converting the high voltage / high current electricity into a suitable voltage or current due to difficulty in measuring, a device including a potential transformer or a current transformer is usually employed.

In other words, in order to avoid the dangers associated with connecting the measuring device directly to the high voltage circuit to measure the voltage of the high voltage circuit, the voltage on the high voltage side is detected by detecting the secondary voltage whose primary voltage is transformed to a relatively low level. As is well known, the transformer for the production includes a secondary winding having a primary winding in which a high voltage is input to an iron core provided in a metal casing, and a winding ratio inducing a target voltage reduced to a target level with respect to the primary winding. It is wound up and configured.

However, according to the transformer of such a configuration, it is easy to cause mutual interference in which the influence of the secondary side is transmitted to the primary side between the primary winding to which a high voltage is applied and the secondary winding to which a target actual voltage is induced. When electrical shocks caused by foreign influences such as lightning strokes, surges, noise, etc. applied to the transformer are induced in the secondary winding and transmitted to the load, malfunction or breakage of the device is likely to occur.

In addition, the higher the voltage applied to the primary winding due to the structure of the transformer, the larger the volume or dimensions of the entire transformer, the larger the size or the size of the insulation, and the higher the weight and the higher the investment cost of the facility. do.

In addition, in transformers having a transformer action by the primary winding and the secondary winding, characteristic changes caused by temperature or humidity or changes over time are accompanied, and waveform distortion occurs due to saturation of the iron core. It is difficult to accurately convert the voltage on the high voltage side.

In addition, a current transformer employed to detect the secondary side current and convert the high side current in order to avoid the danger associated with connecting the measuring device directly to the high voltage circuit when measuring the current of the high voltage line is also known. A secondary winding having a primary winding into which a large current is input in a metal casing and a winding ratio for inducing a target current modified to a target level with respect to the primary winding is wound.

By the way. A current transformer of such a configuration not only causes breakage of the light current transformer that opens the secondary side of the current transformer, but also causes the load to malfunction because of an external influence applied to the current transformer or an electric shock is induced to the secondary side winding. In case of severe or severe damage, it often happens.

An object of the present invention for solving the above problems is to convert the high voltage / high current flowing in the high-voltage line by applying a phototransformer and a photocurrent device to proportionally reduce the voltage / current level of the low level to measure the amount of power The present invention provides an instrument transformer using an optoelectronic device.

According to a preferred embodiment of the present invention, a voltage dividing means for dividing a high voltage on a high voltage line, an optical transformation means for photoelectrically converting a voltage divided by the voltage dividing means into a low level voltage, and a high current flowing on the high voltage line at a low level Light-driving means for driving the light-transforming means and the light-changing means by a constant voltage level, light-receiving element driving means for detecting the voltage / current shifted by the light-transforming means and the light-changing means, and the voltage An instrument transformer using an optoelectronic device is provided which has a signal processing means for processing a signal and a current signal to process voltage and current levels for power quantity measurement.

Preferably, the photovoltaic means is driven by a constant constant current to emit a light beam of a constant amount of light, polarizing means for linearly polarizing the light beam emitted from the light source to the flat light, the light linearly polarized by the flattening means A λ / 4 wavelength plate that phase-polarizes the beam by phase retardation by π / 4, and an optical modulating means for elliptically polarizing the light beam phase-delayed by the λ / 4 wavelength plate for detection of the divided voltage level And a light detecting means for detecting the light beam elliptically polarized by the modulating means, and a light receiving means for receiving the light beam detected by the light detecting means and outputting a target voltage signal.

The polarizing means includes a plurality of polarization slots for linearly polarizing light beams emitted from the light source into flat light, and the optical modulating means is proportional to an electric field formed by application of the divided voltage. It consists of a Pockels effect element that elliptically polarizes the light beams passing through a plurality of polarization slots of the polarizer. Examples of the Pockels element include KDP and ADP (z-cut); LiNbO; Bi SiO is included.

The detection means has a plurality of detection slots having a phase difference of approximately 90 ° from the genital polarizer to detect the light ratio which is phase-delayed by [lambda] / 4 by the [lambda] / 4 wavelength plate and circularly polarized.

The photovoltaic current converting means is a light source driven by a constant constant current level to emit a constant light beam, polarization means for linearly polarizing the light beam emitted from the light source, and a light beam polarized by the polarization means. An optical modulating means for rotating the polarization direction of the light beam according to a magnetic field caused by a current flowing on the high voltage line, a λ / 4 wave plate for rotating the light beam in which the polarization direction is rotated by the optical modulation means in a range of a predetermined angle; And the detecting means for detecting the light beam phase-rotated by the lambda / 4 wavelength plate.

The polarizing means is formed by forming a plurality of slots for polarizing the light beam emitted from the light source to the flat light, the optical modulating means for polarizing the light beam by the target current level by the magnetic field applied by the applied magnetic field The lambda / 4 wavelength plate rotates the phase of the light beam passing through the polarization means in the range of lambda / 4 or 45 °, while the lambda / 4 detection means In order to detect the light beam phase rotated by the wave plate, a plurality of slots different in direction from the polarizing means are formed.

In addition, according to the present invention, the optical modulating means includes paramagnetic and diamagnetic body doping glass; YIG (Y ₃ F ₂ 5012; YTTRIUM IRON GARNET); TGG (TERBIUM GALLIUM GARNET); PB-GLASS; It consists of a material selected from BGO, BSO, and Z _n S _e single crystals.

The light source driving means has an input gain obtained by first and second constant voltage devices having a fixed resistor and a control terminal connected between the power supply and the ground potential, and a variable resistor connected to the connection node of the resistor and the first constant voltage device. An amplifier for differentially amplifying the feedback voltage of the phototransformer / optical current transformer, a MOS transistor of an N channel connected to the output side of the amplifier, a base connected to a source node of a MOS transistor and a connection node of a bias resistor; A transistor having a light source of the phototransformer connected to a collector side commonly connected to a drain side of the MOS transistor, and interposed between an emitter side of the transistor and a ground potential to detect a voltage of a driving current of the light source, thereby providing the amplifier. It is composed of a resistor for feedback.

Further, the light receiving element driving means performs a current mirror action between the first MOS transistor and the first MOS transistor of the P-channel in a constant conduction state, and the current signal received by the light receiving element of the photovoltaic means is variable at the gate end thereof. A second MOS transistor of a P-channel set to a bias level adjusted by a resistance, and an amplifier having a non-inverting input terminal and an inverting input terminal connected to the drain sides of the first and second MOS transistors to differentially amplify the amplifier. A variable resistor is provided for adjusting the offset value.

The signal processing means includes a first amplifier for inverting and amplifying a voltage signal detected by the light receiver, an IC circuit element for performing zero crossing point control on the inverted and amplified voltage signal, and an output of the device. And a second amplifier for amplifying the signal to a voltage level for measuring the amount of power.

According to the instrument transformer using the photoelectric device according to the present invention configured as described above, the voltage / current level suitable for measuring the electric power by adopting a photoelectric transformer device as a transformer means and a photoelectric transformer device as a current transformer means to the high voltage / large current flowing in the high-voltage line The voltage and current signals for measuring the amount of power can be obtained by transforming and transforming the signal into signal processing.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

FIG. 1 is a block diagram of an instrument transformer using an optoelectronic device according to a preferred embodiment of the present invention in a state in which an optical transformer element and an optical transformer element are mixed. In FIG. 1, reference numeral 10 denotes approximately 22,900V. 12 represents a voltage divider made up of a plurality of voltage dividing capacitors (not shown) for dividing a high voltage induced on the high voltage line 10 to a low voltage level, and 14 denotes a voltage divider 12. A phototransformer that proportionally phototransforms the divided voltage to a level applicable to electric power metering.

The phototransformer is driven by a constant constant current light source 30 to emit a light beam of a constant amount of light, a polarizer 31 for linearly polarizing the light beam emitted from the light source 30 into a flat light, the polarizer ( 31) the λ / 4 wave plate 32 and the optical modulator 33 and the optical modulator 33 to polarize the light beam polarized according to the electric field formed by the voltage divided by the voltage divider 12. It comprises an analyzer 34 for detecting the polarized light beam and a light receiving element 35 for receiving the light beam detected by the analyzer 34.

Here, the optical modulator 33 is an elliptical polarization of the light ratio circularly polarized by the λ / 4 wavelength plate 32 corresponding to the divided voltage, and the optical modulator 33 is preferably the voltage divider 12. An element exhibiting a Pockels effect for elliptically polarizing the circularly polarized light beam in proportion to the voltage divided by is employed. Examples of materials having the Pockels effect include KDP and ADP (z-cut); LiNbo; Bi; Sio is included.

In addition, the polarizer 31 which linearly polarizes the light beam emitted from the light source 30 has a plurality of polarization slots 31a having a fine width on the surface thereof, whereby the light source 30 When the emitted light beam passes through the polarizer 31, the shape of the light beam becomes flat light similar to the shape of the polarization slot 31 a formed in the polarizer 31. In addition, the λ / 4 wave plate 32 provided at the rear end of the polarizer 31 delays the phase of the light beam polarized by the polarizer 31 by λ / 4 to circularly polarize the optical modulator 33. When the divided voltage is applied, an elliptically polarized light beam is phase-delayed by λ / 4 by the λ / 4 wavelength plate 32 based on a voltage having a level corresponding to the voltage. .

Therefore, when the divided voltage is applied by the action of the λ / 4 wavelength plate 32 and the optical modulator 33, the light is radiated from the light source 30 and passes through the polarization slot 31a of the polarizer 31. The phase of one light beam changes with the voltage and the light beam of the changed phase is applied to the analyzer 34.

On the surface of the analyzer 34, a plurality of analyzer slots 34a having a fine width similar to the plurality of polarization slots 31a formed on the polarizer 31 are formed. In addition, the plurality of analyzer slots 34a formed in the analyzer 34 are formed in a direction of about 90 ° with respect to the polarization slot 31a on the polarizer 31.

Accordingly, the analyzer 34 serves to detect the light beam whose phase is shifted by the voltage of the target conversion level by the λ / 4 wave plate 32 and the optical modulator 33.

The light receiving element 35 is connected to the rear side of the analyzer 34 to receive a light beam passing through the analyzer slot 34a formed in the analyzer 34 to output an electrical signal.

Here, the formation directions of the polarization slot 31a on the polarizer 31 and the analyzer slot 34a on the analyzer 34 are not limited to the above examples but may be formed in an appropriate direction.

In addition, the optical current conversion element 22 has a shape shown in FIG. 3, that is, a light source 40 that emits light beams by constant voltage driving, and linearly polarizes the light beams emitted by the light source 40 into flat light. A polarizer 41, an optical modulator 42 for polarizing the light beam according to a magnetic field formed by a current flowing through the high voltage line 10, and the optical modulator 42. The light beams passed through the polarizer 41 by phase-rotating the polarized light beams in a π / 4 range or 45 ° in a state in which the + direction component and the-direction component of the primary side current of the sinusoidal phase do not overlap Λ / 4 wavelength plate 43 providing phase shift so that accurate sine wave detection is possible, and an analyzer 44 for detecting light beams phase shifted in π / 4 range by the λ / 4 wavelength plate 43 , The light beam that is inspected through the analyzer 44 The light receiving element 45 for receiving light is provided.

The polarizer 41 which polarizes the light beam emitted from the light source 40 is provided with a plurality of polarization slots 41a of fine width formed in the vertical direction, and thus the light ratio emitted from the light source 40. When the light passes through the polarizer 41, the shape of the light beam is linearly polarized by the flat light similar to the shape of the polarization slot 41a formed in the polarizer 41.

In addition, the optical modulator 42 installed at the rear end of the polarizer 41 is linearly polarized by the polarization slot 41a of the polarizer 41 as described above when a magnetic field corresponding to an external current is applied. The light beam is polarized to a degree corresponding to the magnetic field.

The optical modulator 42 is preferably composed of an element having a Faraday effect indicating that the plane of polarization rotates when a planar polarization passes any isotropic material through a magnetic field coinciding with the traveling direction. As a material having Faraday effect, the adult doping class such as SCHOTT SF-6 GLASS, HOYA FR-5 GLASS, TERIBUM ALUMINA SILLICATE GLASS: YIG (Y ₃ F ₂ 5012 (YTTRIUM IRON GARNET): TGG (TERBIUM GALLIUM GARNET): PB-GLASS: Includes BGO, BSO, Z _n S _e single crystal.

In addition, the λ / 4 wavelength plate 43 coupled to the optical modulator (Faraday element 42) rotates the phase of the light beam polarized by the optical modulator 41 in the range of π / 4 so that the waveform of the sine wave is accurate. When the magnetic field corresponding to the target current level is applied to the optical modulator 42 and the λ / 4 wavelength plate 43, the light is emitted from the light source 40 and the polarizer 41. The light beam passing through the polarization slot 41a is polarized and phase rotated according to the intensity of the magnetic field, and the polarized light and phase rotated light beam is applied to the analyzer 44.

The shape of the analyzer 44 is similar to that of the plurality of polarization slots 41a formed in the polarizer 41, and the shape direction of the analyzer 44 is approximately 90 ° with the polarization slots 41a on the polarizer 41. Multiple inspection slots 44a are formed to have a difference.

Accordingly, the analyzer 44 serves to detect light beams polarized and phase rotated by the optical modulator 42 and the λ / 4 wave plate 43.

The light receiving element 45 is connected to the rear side of the analyzer 44 so as to output a voltage signal corresponding to the metering current of the light beam passing through the slot 44a formed in the analyzer 44.

4 is a light source which is commonly applicable to the driving of light sources 30 and 40 provided in the phototransformer 14 and the optical current transformer 22 shown in FIGS. 2 and 3 in the instrument transformer according to the present invention. The configuration of the driving circuits 16 and 24 is shown. The representative light source driving circuit 16 includes a fixed resistor 51 and a control terminal connected in series between the power supply Vcc and the ground potential GND. First and second constant voltage elements 52 and 53 are included, and a variable resistor 54 is connected to the connection node of the resistor 52 and the first constant voltage device 52, and the variable resistor 54 has a resistor ( 55 and the light source 30; 40 which is connected to the non-inverting input terminal (+) of the differential amplifier 57 through one end of the resistor 56 connected to the ground potential and fed back to the inverting input terminal (-). Differential amplification is performed for the driving voltage of.

The gate of the N-channel MOS transistor 58 is connected to the output side of the amplifier 57, and the drain side of the MOS transistor 58 is connected to the source side of the MOS transistor 58 and the connection node of the bias resistor 59. The base of the transistor 60 to which the light source 30 of the phototransformer is connected is connected to the collector side connected to the common, and the driving current level of the light source 30 is connected between the emitter side of the transistor 60 and the ground potential. The current detection resistor 61 which tracks this to the amplifier 57 is interposed.

In addition, the light source driving circuit 24 driving the light source 40 of the optical variable current element 22 also performs the driving of the light source 40 by a similar configuration to the light source driving circuit 16.

FIG. 5 is a diagram showing the configuration of the light receiving element driving circuits 18 and 26 and the signal processing circuits 20 and 28 shown in FIG. 1, and the representative light receiving element driving circuits 18 and the signal processing circuits 20 are shown. ), A plurality of series resistors 71, 72, 73 are connected to the output side of the light receiving element 35, and capacitors 74 are connected at both ends of the resistors 72, 73, and the resistors 71, 72 are connected. A second P-channel MOS transistor driven by a current of a light receiving signal of the light-receiving element 35 while a gate mirrors a current of the first P-channel MOS transistor 76 in which the gate is always set to ground potential. The base of 77 is connected, and the source of the first transistor 76 is connected to the source side of the second transistor 77. On the drain side of the first and second transistors 76 and 77, resistors 78 and 79 for forming a potential to cause the transistors 76 and 77 to perform a current mirroring function are correspondingly connected, and genital resistance ( At the connection points of 78 and 79, a resistor 80 is connected for potential balance.

On the drain side of the first and second transistors 76 and 77, an inverting input terminal (-) and a non-inverting input terminal (+) of the first amplifier 81 for differentially amplifying the signal current detected by the light receiving element 35 Is connected to the first amplifier (81), and a resistor (82) and a capacitor (83) for potential stabilization are connected to the negative power supply (-Vcc) and the offset value of the first amplifier (81) is adjusted. The resistor 84 for the capacitor, the capacitor 85 and the variable resistor 86 are connected.

The inverting input terminal (-) of the inverting amplifier 88 is connected to the output side of the first amplifier 81 via a resistor 87, and the inverting amplifier 88 has potential stabilization with respect to the negative power supply (-Vcc). The resistor 89 and the capacitor 90 are connected, and the resistor 91, the capacitor 92 and the variable resistor 93 for adjusting the offset value with respect to the inverting amplifier 88 are connected, and the inverting amplifier ( The amplification degree of 88 is determined by the resistor 87 and the resistor 94.

A filter made of a resistor 95, a capacitor 96 and a resistor 97 is connected to the output side of the inverting amplifier 88, and a capacitor 99 is connected to the input side via a smoothing capacitor 98 at the rear end of the filter. And a zero crossing point adjustment IC element 101 with the resistor 100 added thereto.

The IC element 101 is preferably an AD534J type IC manufactured by Analog Devices.

The non-inverting input terminal (+) of the second amplifier 102 is connected to the output side of the IC element 101, and the amplification of the second amplifier 102 is determined by the resistor 103 and the resistor 104.

In addition, the second amplifier 102 is connected to a resistor 105 for potential stabilization and a capacitor 106 with respect to a negative power supply (-Vcc), and a resistor for adjusting an offset value with respect to the second amplifier 102 ( 107, the capacitor 108 and the variable resistor 109 are connected.

A resistor 110 and a smoothing capacitor 111 are connected to the output side of the second amplifier 102 so that a voltage signal for integration measurement is detected and applied to the power meter.

In addition, a circuit configuration similar to the light receiving element driving circuit 18 and the signal processing circuit 20 is also applied to the light receiving element 45 of the optical variable current element 22 to detect a voltage signal corresponding to the current value for metering. And is applied to the electricity meter.

Next, the operation of the transformer for the instrument according to the present invention configured as described above will be described in detail.

The high voltage induced in the high voltage line 10 is applied to the photovoltaic element 14 in a state where the voltage is divided by the voltage divider 12 at a constant level, and the magnetic field formed by the current induced on the high voltage line 10 is photocurrent. Is applied to the element 22.

In this state, the light source driving circuits 16 and 24 which are commonly applicable to the phototransformer 14 and the photocurrent converting element 22 may be provided with a resistor 51 and first and second resistors with respect to a voltage of a power supply (+ Vcc). The non-inverting of the differential amplifier 57 is driven by the light source driving voltage set by the variable resistor 54 while the constant current level is always set by the rated voltages of the constant voltage elements 52 and 53 via the resistors 55 and 56. Applied to the input terminal (+), the MOS transistor 58 is brought into a conductive state by the voltage output level of the differential amplifier 57, and a base is provided between the source of the MOS transistor 58 and the resistor 59. The connected transistor 60 is brought into a conducting state so that the light sources 30 and 40 of the phototransformer 14 and the photocurrent conversion element 22 are turned on to emit light beams.

The driving current level of the light sources 30 and 40 is detected as a voltage by a resistor 61 connected to the emitter side of the transistor 60 and fed back and amplified to the inverting input terminal (-) of the differential amplifier 57. In addition, it is possible to secure a constant driving current level with respect to the light sources 30 and 40.

The light beams emitted from the light sources 30 and 40 first pass through the polarization slot 31a of the polarizer 31 constituting the optical transformer element 14 shown in FIG. 2 in the case of the optical transformer element 14. It linearly polarizes with flat light. Subsequently, the light beam polarized by the polarizer 31 is delayed in phase by π / 4 in the λ / 4 wavelength plate 32 to be circularly polarized, and then incident on the optical modulator 33. ) Is elliptically polarized on the basis of the voltage of the light beam due to the voltage level divided by the voltage divider 2.

That is, when the divided voltage is applied to the optical modulator 33, the light beam circularly polarized by the λ / 4 wavelength plate 32 is elliptically polarized to a degree proportional to the voltage, and is elliptical by the optical modulator 33. The deflected light beam is applied to the analyzer 34.

When an elliptically polarized light beam is incident on the analyzer 34, a plurality of minute detector slots having an angle difference of 90 ° with the polarization slot 31 of the polarizer 31 formed on the analyzer 34. Detection is performed by 34a, and the detected light beam is received by the light receiving element 35 connected to the light receiving element driving circuit 18.

In addition, the light beam radiated to the light source 40 of the light conversion element 22 is directed toward the polarizer 41 and passes through a plurality of fine polarization slots 41a formed on the polarizer 41. In the present invention, flat light having a horizontal direction corresponding to the direction of the slot 41a is obtained. The light beam polarized in the shape of a plate in the polarizer 41 is incident on the optical modulator 42. As the optical modulator 42 is applied with a magnetic field having a current level induced by the high voltage line 10, The light beam is polarized due to the characteristics of the optical modulator 42, and the deflected light beam is rotationally displaced by [pi] / 4 or 45 [deg.] In the [lambda] / 4 wavelength plate 43.

That is, in the optical modulator 42 and the λ / 4 wave plate 43, when the current of the high voltage line 10 is induced, the light beam is deflected corresponding to the magnetic field formed by the current, and the phase is π / 4. The light beams having passed through the optical modulator 42 and the λ / 4 wavelength plate 43 are phase shifted relative to the direction at which the light beam passes through the polarizer 41. 44).

When the phase beam is incident on the analyzer 44, the amount of light beams passing through the analyzer slot 44a of the analyzer 44 is detected by the light receiving element 45, and the light receiving element driving circuit 26 Is applied to.

Here, the device has a magneto-optical effect in which the phase angle of polarization is rotated when the magnetic field is applied to the optical crystal device and the polarized light is incident on the optical crystal device. By employing a Faraday crystal element in which the polarization plane rotates due to the change of the magnetic field, an optical current transformer for measuring the secondary current is provided.

That is, as the light beam passes through the Faraday crystal element, the polarization plane is rotated under the influence of the magnetic field applied by the current control means, and the rotation angle θ of the polarization is

Where V is the Verdet constant, H is the magnetic field to be applied, L is the length of the Faraday crystal element, and θ a is the optical flexibility that can be used as the optical bias.

In order to set θ = 45 °, the length L of the Faraday crystal element is set to 4.6 mm.

Therefore, if the intensity of light reaching the light receiving element from the light source is I, I = I ₀ (1 + sin 2VHL) (wherein I ₀ is the intensity of light when no magnetic field is applied), and thus when the magnetic field is not applied. By measuring the amount of light, the magnetic field can be measured.

Since the detected light amount is proportional to the applied magnetic field and the magnetic field is proportional to the current flowing in the conductor, the current flowing through the high voltage line 10 is detected as the amount of light to convert the secondary side current.

The light receiving element driving circuits 18 and 26 which receive the converted voltage signal or the converted current signal detected by the light receiving element 35 of the optical transformer element 14 or the light receiving element 45 of the optical transformer element 22 are provided. A constant current always flows to the drain side of the first transistor 76 of the P-channel in which the gate is always at ground potential, so that the voltage of the potential formed by the resistor 79 is lower than that of the first amplifier 81. It is set in the non-inverting input terminal (+).

In this state, the gate voltage of the second transistor 77 of the P-channel is set to a level at which the current value of the converted voltage signal or the converted current signal detected by the light receiving elements 35 and 45 is set by the resistors 72, 74, and 75. Since it is applied to drive the side, the voltage of the potential, which is formed at the connection node of the drain side of the second transistor 7 and the resistor 780, is applied to the inverting input terminal (-) of the first amplifier 81 to differentially amplify. Subsequently, the sub-power stabilization by the resistor 82 and the capacitor 83 is taken for the first amplifier 81, and the offset value is adjusted by adjusting the variable resistor 86.

The signal differentially amplified by the first amplifier 81 is applied to the inverting input terminal (−) of the inverting amplifier 88 to be inverted and amplified by the amplification by the resistors 87 and 94 and offset of the inverting amplifier 88. The value is adjusted by the variable resistor 93 and the potential stabilization is realized by the resistor 89 and the capacitor 90.

The output of the inverting amplifier 88 is smoothed by the capacitor 98 in the filtered state by the resistors 95 and 97 and the capacitor 96, and is applied to the zero adjustment IC element 101 so that the output of the inverting amplifier 88 is rotated in the forward direction. The signal level biased in the + or negative direction is adjusted to match zero.

The zero adjustment signal of the zero adjustment IC element 101 is applied to the non-inverting input terminal (+) of the second amplifier 102 and amplified by the amplification by the resistors 103 and 104 to be the resistance 110 and the capacitor 111. Is output as a voltage signal corresponding to the voltage signal level or the current signal level for integration in the smoothed state and applied to the meter.

FIG. 6 is a view showing the insulator structure of the transformer for the instrument in which the optical transformer element 14 and the optical current transformer element 22 shown in FIG. 2 and FIG. 3 are housed. An upper part of the insulator 120 of the insulator A bus bar 121 is installed to induce high pressure in the transformer, and the high voltage line 10 is connected to one end 121a of the bus bar 121 while the other end 121b is located on the receiver side. The feeder is connected.

In addition, a plurality of bolts 122 and 123 for fixing the bus bar 121 to the insulator 120 are provided at a predetermined position of the bus bar 121, among which the ends 122a of the bolt 122 are provided. A voltage divider 12 including a plurality of capacitors (not shown) is contacted to divide the high pressure flowing through the bus bar 121, and the polarizer 31 of the phototransformer 14 is disposed below the voltage divider 12. And the λ / 4 wavelength plate 32, the optical modulator 33 and the analyzer 34 are modularly arranged in the form of an optical sensor.

In addition, at a predetermined position of the bus bar 121, a polarizer 41 and an optical modulator (22) of the optical current conversion element 22 are disposed between ends of the core 42a to detect a current induced in the high voltage line 10. 42, the λ / 4 wavelength plate 43 and the analyzer 44 are modularized to form an optical sensor, and the light source 40 and the light receiving element 45 of the optical current conversion element 22 are insulated ( The optical cables 126a and 126b that extend along the inner space 125 of the 120 are optically connected through an optical connector (not shown).

The optical transformer 14 may be optically connected to a storage space 120a formed below the insulator 120 by a terminal (not shown) and an optical cable (not shown) formed in the voltage divider 12. And a light source 30 and a light receiving element 35 of the light source 30, and a light source 40 and a light receiving element 45 of the optical current conversion element 22, which are connected to the optical cables 126a and 126b. In addition, a PCB circuit (not shown) of each of the light source driving circuits 16 and 24, the light receiving element driving circuits 18 and 26, and the signal processing circuits 20 and 28 for each light source 30 and 40 is disposed. The weighing signal (voltage / current) obtained from the signal processing circuits 20 and 28 is applied to the weighing instrument via the conducting wire 128.

As described above, according to the instrument transformer employing the photoelectric element of the present invention, since the high voltage / large current flowing through the high-voltage line is adopted to the signal of the voltage level and current level suitable for metering by adopting the photoelectric element, In addition to the reduction in volume and weight, the transformer / current action by the photoelectric device is performed, which not only significantly improves the noise ratio of the signal, but also significantly improves the insulation effect and extends the life semipermanently. .

On the other hand, the present invention is not limited to the above examples, and various changes and modifications are possible without departing from the gist and gist of the invention.

Claims (4)

A transformer for proportionally modifying a high voltage / large current flowing in a high voltage line to a low voltage / small current suitable for metering, the transformer comprising: a voltage dividing means (12) connected to the high voltage line (10) to divide the high voltage flowing on the line; Optical transformer means (14) for photoelectrically converting the voltage divided by the voltage dividing means (12) into a voltage having a low level; Optical current flowing means (22) for photoelectrically converting a large current flowing on the high voltage line (10) to a low level; Light source driving means (16; 24) for driving the optical transformer means (14) and the optical transformer means (22) by a constant voltage level; Light-receiving element driving means (18; 26) for detecting the voltage / current flowed by the optical transformer means (14) and the optical transformer means (22); And a signal processing means (20; 28) for processing the voltage signal and the current signal to process the voltage and the current level for power quantity measurement. 2. The light source driving means (16; 24) according to claim 1, further comprising: first and second constant voltage elements (52, 53) having a high resistance (51) and a control terminal connected in series between a power source and a ground potential; The input gain is controlled by the variable resistor 54 connected to the connection node of the fixed resistor 51 and the first constant voltage device 52 to differentially amplify the feedback voltage of the phototransformer / photocurrent converters 14 and 20. An amplifier 57; A base is connected to the N-channel MOS transistor 58 connected to the output side of the amplifier 57, the connection node of the MOS transistor 58 and the bias resistor 59, and is common to the drain side of the MOS transistor 58. A transistor (60) to which a light source (30; 40) of the phototransformer (current) device (14; 20) is connected to the connected collector side; And a resistor 61 interposed between the emitter side of the transistor 60 and the ground potential to detect the driving current level of the light sources 30 and 40 and feed it back to the amplifier 57. Instrument transformer using optoelectronic device. 2. The light receiving element driving means (18; 26) according to claim 1, further comprising: a P-channel first MOS transistor (76) in a constant conduction state; The current signal received by the light receiving elements 35 and 45 of the photovoltaic transformer / current converting means 14 and 20 is applied to the variable resistor 75 while performing a current mirror action with the first MOS transistor 76. A second MOS transistor 77 of the P channel set to the bias level adjusted by the P channel; And a non-inverting input terminal and an inverting input terminal connected to the drain sides of the first and second MOS transistors (76, 77) for amplifier amplification. 2. The apparatus of claim 1, wherein the signal processing means (20; 28) comprises: a first amplifier (88) for inverting and amplifying the voltage signal detected by the light receiving elements (35; 45); An IC for filtering the inverted-amplified voltage signal output from the first amplifier 88 and a filter element (95, 96, 97) by a capacitor and a zero crossing control for the filtered signal. Circuit element 101; And a second amplifier (102) for amplifying the output signal of the IC circuit element (101) for measuring the amount of power and outputting a metering signal (voltage / current).