JPS5990061A - Device for transmitting output signal of capacitance potential device - Google Patents

Abstract

PURPOSE:To eliminate a noise, to simplify a device and to obtain a signal voltage of high precision by processing two output signals of a capacitance potnetial device having wide band region frequency characteristics all by an optical system without using an electronic circuit. CONSTITUTION:Laser light of an optical source 91 is sent to electro-optic effect elements 93, 94 through a polarizing element 92, and a devided voltage of the capacitance potential device for power transmission line and similarly a compensation voltage are impressed to elements 93 and 94, respectively. Thus, the phase difference due to double refraction of normal light and abnormal light subjected to optical modulation by the devided voltage is compensated to desired value. This output light is transmitted remotely by an optical fiber 96 through a photoanalyzer 95, and received by a photodetector 97, and converted to an electric signal and said signal is supplied to a signal voltage indicater 98 to indicate the measured voltage. All signals are processed optically by usch constitution, the signal transmitting device is simplified remarkably and simultaneously the anxious noise at this part is eliminated and the effect of incoming induction impediment such as switching serge is removed also in the transmitting path. Thus the signal voltage of high precision can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitor-type potential transformer, in particular, which improves the frequency characteristics and increases the fundamental frequency (commercial frequency 50 or 601).
Z) and the output signal of a capacitor-type instrument transformer that can accurately transform the voltage at frequencies other than those around twice the fundamental frequency, without being affected by external induction disturbances, using a simple device. The present invention relates to a single capacitor type potential transformer output signal transmission device for accurately transmitting signals to a desired remote location.

The present inventors first proposed an fs capacitor type voltage transformer with broadband frequency characteristics and an output signal transmission device for accurately transmitting the output signal of this transformer to a desired remote location. .

Therefore, first, for convenience of explanation of the present invention, the above-described apparatus proposed by the present inventors will be explained based on FIG. 1.

In Fig. 1, 1 and 2 are f main capacitors and voltage dividing capacitors which are connected in series, and one end of the main capacitor 1 is connected to a high voltage line 7 such as a power transmission line or a bus bar with voltage E1. Further, the voltage dividing capacitor 2 at the other end of this series circuit is divided into capacitors 21 and 22.

These relationships are selected to be 1±1,000 1=1, where the capacitance of the voltage dividing capacitor 2 is 02, and the capacitances of the capacitors 21.22 are C21 and C22, respectively.・Ru.

021 022 02 6 has one end connected to the ground terminal of the voltage dividing capacitor 2,
The other end is connected to the primary winding of the transformer 40 and is a single resonant handle. The other end of the primary winding of the transformer 40 is connected to a connection point between the main capacitor 1 and the voltage dividing capacitor 2.

One end of the transformer 40 secondary winding is grounded.

5 is a secondary load of the transformer 4, and a secondary voltage E2 appears at both ends thereof. 6 is an auxiliary capacitor Qj connected between the terminals of the resonant axle 6, and the relationship between the capacitance of the auxiliary capacitor 1, the voltage dividing capacitor 2, and the auxiliary capacitor B, and the interface L of the resonant axle 3 is □Coni 7 ----2-0=2πf.

7 (cl + 02 + 06) L 1□22πf 1 stroke However, f〇-commercial frequency, f=stopping frequency.

The conditions are met.

Therefore, the auxiliary capacitor 6 is also divided into two, consisting of capacitors 61 and 62 connected in series, and the relationship between them is C6-1 + 062-66-, assuming that the capacitance of capacitors 61 and 62 is 061.1 1-1 C62. The shared voltage of the capacitor 22, Ecz2
and the terminal voltage of the capacitor 62, that is, the compensation voltage Ea
62 is input to the differential combiner 66.

In the f-capacitor type potential transformer configured in this way, the shared voltage EO22 of the capacitor 22 and the compensation voltage Ec62 of the capacitor 62 are differentially combined, so the shared voltage EC22 of the capacitor 22 normally has a load of 50%. , whose magnitude and phase change depending on the type, and the change in this shared voltage EC22 is compensated for by the compensation voltage EC6.
2 can differentially track and compensate for changes in magnitude and phase, and the output side of the differential combiner 66 has a voltage E.
It is extremely convenient to be able to obtain a signal voltage 64 with a broadband waveform that is the same in amplitude, waveform, and phase as 1. A code converter 65 for code conversion such as frequency-voltage conversion (V/F), a light emitter 66, and an optical fiber 6
7. It was proposed that the voltage be measured by supplying it to, for example, a voltage indicator 40 via a photodetector 8 and a demodulator 69.

With this configuration, the output signal 64 of the combiner 66 is sent to the transducer 65, then supplied to the light emitter 66, converted into an optical signal, and transmitted through the optical fiber 67. After transmission, this signal is supplied to a demodulator 69 via a photodetector 38, demodulated, and displayed on a voltmeter 40.

As a result of converting the output signal 64 into an optical signal and transmitting it in this way, it is possible to eliminate disturbances to the transmission path caused by so-called switching surges that occur when a disconnector or circuit breaker opens and closes, and also to improve the attenuation characteristics, phase characteristics, etc. It is very convenient that the balance can also be improved.

However, this transmission device uses an electronic circuit, a t-component differential combiner, a coded modulator, etc., which makes the device complicated, and there is a risk of picking up noise in this part, making it impractical. There are some shortcomings.

The present invention has been proposed in consideration of this point.According to the present invention, two output signals from a capacitor-type voltage transformer having broadband frequency characteristics can be transmitted by an optical system without using an electronic circuit. The apparatus is much simpler than the one shown in FIG.

The present invention will be explained below based on FIG. In Figure 2,
91 is a light source such as a laser beam or a light emitting diode (LED), 92 is a polarizer, and 93.94 is a crystal such as ammonium, Te, hydrophoshyde (ADP), niobium sanlithium (L 1Nb06), tantalum sanlithium (
95 is an analyzer, 96 is an optical fiber, 97 is a light receiver, which is a solar cell and a PIN diode, and the output thereof is indicated by a voltage indicator 98.

Thus, to the element 96, a divided voltage EC22 from the f capacitor type voltage transformer shown in FIG. be done. Therefore, the phase difference due to birefringence between the ordinary ray and the extraordinary ray can be corrected to a desired value by optically modulating the divided voltage 22.

This output light passes through an analyzer 95 and is directly transmitted to 5 optical fibers 9.
6, the signal is received by a light receiver 9, converted into an electrical signal, and supplied to a signal voltage indicator 98 to indicate the measured voltage.

In the signal transmission device according to the present invention, everything is processed by an optical system and does not use a differential combiner using an electronic circuit, a coded modulator, etc., so the device is smaller than the single signal transmission device shown in FIG. Not only is it significantly simplified and there is no need to worry about noise in this part, it is also an ultra-compact element with an ultra-low frequency band, so it can be easily incorporated into an existing capacitor-type voltage transformer. Furthermore, it is advantageous in dealing with external induced disturbances, and it is possible to obtain a signal voltage with higher precision, thereby significantly increasing practicality.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of a capacitor-type instrument pressure regulator having broadband frequency characteristics and a transmission path for its output signal, which was previously proposed by the present inventors, and FIG. 2 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram schematically showing an optical transmission path for a signal voltage obtained by a capacitor type voltage transformer having broadband frequency characteristics.

Claims (1)

[Claims] A main capacitor, a voltage dividing capacitor connected in series to the main capacitor, a series circuit connected to both ends of the voltage dividing capacitor including the primary winding of the transformer and a resonant axle, and a series circuit connected to the resonant reactor in parallel with the resonant reactor. It consists of connected auxiliary capacitors, and the capacities of the main capacitor, voltage dividing capacitor, and auxiliary capacitor are respectively C1, C2, and C6, and the inductance of the resonant axle is L, f, and 1--==2πf. . j ko5t〒7chi106)L 1=2πf jkanπ However, fO satisfies the conditions of the commercial frequency and f the blocking frequency, and the voltage dividing capacitor and the auxiliary capacitor are divided into halves by quantity ratio, The divided voltage obtained from this two-part voltage dividing capacitor and the compensation voltage obtained from the auxiliary capacitor are respectively converted into a light source, a polarizer, an electro-optic differential transformer consisting of two electro-optic effect elements, an analyzer, 1. A capacitor-type instrument transformer comprising a light receiver and a signal voltage indicator, and input to the electro-optic differential transformer of one optical system.