Electronic voltage sensor

Abstract

The present invention relates to an electronic voltage sensor capable of minimizing a change in output according to temperature by applying a phase change material. An electronic voltage sensor according to one embodiment of the present invention comprises: a pair of electrodes which are formed in a ring shape so that a conductor passes therethrough, and which are concentrically disposed; a ring-shaped insulator concentrically disposed between the pair of electrodes; and a molding unit for molding and integrating the pair of electrodes and the insulator, which are stacked, wherein the molding unit can include a phase change material.

Description

electronic voltage sensor

[0001] The present invention relates to an electronic voltage sensor capable of minimizing changes in output according to temperature.

[0002] Due to the demand for digital substations in existing and newly expanded substations and regulations on the use of SF6 gas, the application of low-power voltage transformers (LPVT) is being considered along with the transition to intelligent and eco-friendly GIS at the design stage for gas-insulated switchgear (GIS).

[0003] Low-power instrument transformers intended to replace existing instrument transformers are measuring instruments that measure the actual voltage of a power system into a divided low voltage and output signals for monitoring the operating status of the GIS and for the rapid operation of the Merging Unit (MU) and Intelligent Electronic Device (IED) for switching the GIS in the event of a fault, and thus require high precision and non-error performance.

[0004] These low-power instrument transformers can use electronic voltage sensors, and the output of the voltage sensor is determined by the voltage division ratio of the insulating gas (SF6 gas or eco-friendly gas) present between the conductor of the GIS and the voltage sensor, and the capacitance of the voltage sensor itself.

[0005] However, the operating environment of the GIS, that is, temperature changes outside and / or inside the GIS tank, cause these capacitance values ​​to change, which in turn causes changes in the output of the voltage sensor and ultimately leads to performance degradation of the low-power instrument transformer. For example, when the temperature changes from -40℃ to 40℃, the output of the voltage sensor may change by about 4% to -1.2% compared to when it is at 25℃.

[0006] To overcome this problem, a method of applying a temperature compensation function to a signal conversion circuit connected to a voltage sensor and transmitting an input signal to a merging unit is being considered. To implement this, data regarding the output and phase change of the voltage sensor in each temperature range must be measured under conditions of applying a rated voltage, but in reality, it is difficult to obtain experimental data, so the temperature compensation function cannot be implemented.

[0007] The present invention aims to provide an electronic voltage sensor capable of minimizing changes in output with temperature by applying a phase change material (PCM).

[0008] An electronic voltage sensor according to one embodiment of the present invention comprises: a pair of electrodes formed in a ring shape and arranged concentrically so that a conductor passes through them; a ring-shaped insulator arranged concentrically between the pair of electrodes; and a molding portion formed by molding the stacked pair of electrodes and the insulator to form an integrated structure, wherein the molding portion may include a phase change material.

[0009] In an electronic voltage sensor according to another embodiment of the present invention, the molding portion includes an overlapping first molding and a second molding, and the first molding in which the pair of electrodes and the insulator are embedded may be formed by being embedded within the second molding.

[0010] According to an embodiment of the present invention, the phase change material molded into the electronic voltage sensor undergoes an endothermic or exothermic reaction to temperature changes occurring, for example, outside and / or inside the tank of the GIS, thereby maintaining the output of the voltage sensor constant or minimizing changes in output, and accordingly, the effect of satisfying high precision and non-error performance of a low-power instrument transformer employing the electronic voltage sensor is obtained.

[0011] FIG. 1 is a perspective view illustrating a voltage sensor according to a first embodiment of the present invention.

[0012] FIG. 2 is a partial cross-sectional view of a voltage sensor installed according to a first embodiment of the present invention.

[0013] FIG. 3 is a front view and a cross-sectional view illustrating a voltage sensor according to a second embodiment of the present invention.

[0014] The present invention is described in detail below with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings.

[0015] In addition, for convenience of explanation, the present specification describes and illustrates the invention primarily with examples in which an electronic voltage sensor is applied as a low-power instrument transformer of a GIS, but the invention is not necessarily limited thereto. The voltage sensor of the present invention may also be applied to any other device, such as a substation equipped with an instrument transformer in an insulating gas atmosphere.

[0016] FIG. 1 is a perspective view illustrating a voltage sensor according to a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of a voltage sensor according to a first embodiment of the present invention installed.

[0017] As illustrated in FIGS. 1 and 2, a voltage sensor (10) according to a first embodiment of the present invention may include a pair of electrodes (11, 12), an insulator (13), and a molding part (14).

[0018] A pair of electrodes (11, 12) can be formed into a ring shape using a metallic conductor with excellent electrical conductivity, such as copper or silver. A pair of electrodes may include a first electrode (11) and a second electrode (12), wherein the diameter of the first electrode is smaller than the diameter of the second electrode.

[0019] A pair of electrodes (11, 12) can be arranged concentrically. In other words, a first electrode (11) with a relatively small diameter can be positioned inside a second electrode (12) with a relatively large diameter.

[0020] Additionally, a pair of electrodes (11, 12) may have substantially the same width (W; axial length) and the same thickness (T; radial length).

[0021] Signal lines (15, 16) for voltage sensing can be physically and electrically connected to each electrode (11, 12) by, for example, soldering. For example, a positive (+) signal line (15) can be connected to the first electrode (11), and a negative (-) signal line (16) can be connected to the second electrode (12).

[0022] The insulator (13) can be formed into a ring shape using a flexible insulating material such as fiber reinforced plastics (FRP) or polyimide (PI) resin.

[0023] The diameter of the insulator (13) is larger than the diameter of the first electrode (11) and smaller than the diameter of the second electrode (12). The insulator can be arranged concentrically with a pair of electrodes. In other words, the insulator can be positioned inside the second electrode, which has a relatively larger diameter, and the first electrode, which has a relatively smaller diameter, can be positioned inside the insulator.

[0024] Additionally, the insulator (13) is preferably made to have a width (W') greater than the width (W) of a pair of electrodes (11, 12). For example, in order to stably connect a signal line (15) to a first electrode (11) located radially inside the insulator, the signal line can be fixed to the insulator by soldering or the like and then connected to the first electrode through the insulator.

[0025] The molding part (14) is formed such that an insulator (13) is interposed between a pair of electrodes (11, 12) and the stacked pair of electrodes and the insulator are molded into a ring shape by a molding material and covered and fixed to each other. With this molding part, the pair of electrodes and the insulator are integrated to form a single voltage sensor (10).

[0026] As a molding material, an insulating material such as epoxy resin, acrylic resin, silicone, etc. may be adopted. In this way, the molding part (14) allows a pair of electrodes (11, 12) and an insulator (13) to be completely sealed and bonded during the process of molding with the molding material, and also allows the shape of the voltage sensor (10) to be stably maintained.

[0027] The voltage sensor (10) configured in this manner can precisely measure the voltage flowing through the conductor (1) using the capacitance voltage division principle. The ring-shaped voltage sensor is formed and mounted so that the conductor through which current flows passes, and thus the magnitude of the voltage can be detected in a non-contact manner. Therefore, the voltage sensor can omit the iron core, and thereby eliminate the occurrence of iron resonance.

[0028] As illustrated in FIG. 2, when an electronic voltage sensor is applied to a device in an atmosphere of insulating gas, such as GIS, for example, when the voltage sensor (10) is installed in a tank (2) such that it surrounds the conductor (1), that is, penetrates through the conductor, a voltage divider circuit can be formed with a first capacitance (C1) that acts between the conductor in the tank and the voltage sensor, such as SF6 gas or an eco-friendly gas, and a second capacitance (C2) that is possessed by the voltage sensor itself, that is, that is, in the insulator (13) and the molding part (14).

[0029] In this voltage divider circuit, the voltage divider ratio of the voltage sensor (10) varies according to the capacitance, and while the value of the second capacitance (C2) can be maintained constant as the combined value of the capacitances of the insulator (13) and the molding part (14), the value of the first capacitance (C1) changes according to the temperature of the insulating gas.

[0030] Accordingly, for example, the temperature of the insulating gas can be measured from a temperature sensor (not shown) mounted on the tank (2) of the GIS, and the value of the first capacitance (C1) can be obtained by correcting the capacitance of the insulating gas with the rate of change of capacitance according to the measured temperature, that is, the temperature coefficient of capacitance.

[0031] The partial pressure ratio can be expressed by the following mathematical formula.

[0032]

[0033] Here, C1 is the first capacitance [F] due to the insulating gas, C2 is the second capacitance [F] possessed by the voltage sensor itself, Up is the voltage [V] applied by the conductor, and Uout is the voltage [V] output from the voltage sensor.

[0034] As described above, for example, in the case where the voltage sensor (10) is installed to surround the conductor (1) within the tank (2) of the GIS, that is, to be penetrated by the conductor, the voltage sensor may be installed in the connecting ring unit of the tank. The connecting ring unit may connect the first tank and the second tank by contacting each of these tanks between the first tank and the second tank constituting the tank. The connecting ring unit may be positioned adjacent to the circuit breaker constituting the GIS in the tank.

[0035] Here, the configuration and arrangement relationships of the connecting ring unit for installing the electronic voltage sensor and the transmitting unit that receives measurement information from the voltage sensor, amplifies it, and transmits it to the data processing unit are described in detail in the applicant's Korean Registered Patent No. 2458873. Therefore, the description and illustration thereof are omitted in this specification, and it is merely noted that the contents of the aforementioned patent may be incorporated by reference into this specification.

[0036] An electronic voltage sensor (10) according to the first embodiment of the present invention is characterized in that the molding part (14) includes a phase change material.

[0037] Phase change materials refer to materials that can absorb or release a large amount of heat by changing their form from solid to liquid, liquid to gas, or vice versa at a specific temperature without a change in temperature; they are materials that function as latent heat sources, heat storage materials, or thermal regulators, storing ambient heat on their own and releasing it when needed.

[0038] As such, the heat absorbed or released by a phase change material while maintaining a constant temperature during a phase change is called latent heat. For example, when heat is applied to a phase change material in a solid state, the material absorbs a certain amount of heat as it changes shape from solid to liquid when it reaches its melting point. Despite the input of heat, the phase change material remains at a constant temperature and retains latent heat.

[0039] Conversely, when a phase change material changes its form from liquid to solid, it releases stored latent heat to maintain a constant temperature. In other words, the phase change material absorbs ambient heat to keep the temperature low above a certain level, while releasing stored heat to keep the temperature high below that level, thereby ultimately enabling the maintenance of a constant temperature.

[0040] Latent heat plays a crucial role in energy storage during phase changes. Because latent heat possesses tens to hundreds of times greater thermal energy storage and release capabilities at the phase change temperature compared to sensible heat, it can perform superior functions compared to conventional energy-saving materials that utilize sensible heat.

[0041] Phase change materials that undergo phase changes at various temperatures can be classified into organic materials, inorganic materials, and plant materials obtainable from nature. The phase change materials mentioned in this specification may be applied such that the temperature at which the phase change occurs varies depending on ambient conditions.

[0042] For example, based on a range of approximately 0°C to 25°C, organic powder-type alkane hydrocarbon compounds protected by microcapsules may be used for low temperature conditions below freezing. Specifically, dodecane, tridecane, tetradecane, pentadecane, etc. may be used.

[0043] Under high temperature conditions exceeding 25°C, inorganic powder-type manganese nitrate hexahydrate (Mn(NO3)2·6H2O), manganese nitrate tetrahydrate (Mn(NO3)2·4H2O), zinc nitrate hexahydrate (Zn(NO3)2·6H2O), sodium sulfate decihydrate (Na2SO4·10H2O), sodium acetate trihydrate (CH3COONa·3H2O), etc. may be used.

[0044] In the electronic voltage sensor (10) according to the first embodiment of the present invention, a molding part (14) may be formed by mixing a corresponding phase change material according to the target with a target, targeting a low temperature condition or a high temperature condition so that the release of heat absorption or latent heat regarding the temperature around the voltage sensor occurs smoothly.

[0045] To this end, the molding portion (14) of the electronic voltage sensor (10) according to the first embodiment of the present invention can be formed by stirring a molding material containing a phase change material according to a target temperature condition, and then using a mold to mold the molding material to a uniform thickness over a stacked pair of electrodes (11, 12) and an insulator (13).

[0046] As described above, according to the first embodiment of the present invention, the phase change material molded into the electronic voltage sensor undergoes an endothermic or exothermic reaction to temperature changes occurring, for example, outside and / or inside the tank of the GIS, thereby maintaining the output of the voltage sensor constant or minimizing changes in output.

[0047] For example, when an electronic voltage sensor is applied to a device in an atmosphere of insulating gas such as GIS, the change in the value of C2 (the second capacitance [F] possessed by the voltage sensor itself) of the voltage sensor due to temperature change can be minimized, thereby maintaining the constancy of the value of C2 output from the voltage sensor regardless of temperature change.

[0048] Accordingly, according to the first embodiment of the present invention, the effect of satisfying high precision and non-error performance of a low-power instrument transformer employing an electronic voltage sensor is obtained.

[0049] FIG. 3 is a front view and a cross-sectional view illustrating a voltage sensor according to a second embodiment of the present invention.

[0050] As illustrated in FIG. 3, a voltage sensor (10) according to a second embodiment of the present invention may include a pair of electrodes (11, 12), an insulator (13), and a molding part (14).

[0051] The second embodiment illustrated in FIG. 3 differs only in that the molding part (14) includes a first molding (17) and a second molding (18), and the remaining components are identical to the components of the first embodiment. Accordingly, in describing the voltage sensor (10) of the second embodiment, the same reference numerals are assigned to components identical to the voltage sensor according to the first embodiment described above, and the detailed description of their configuration and function is omitted.

[0052] A voltage sensor (10) according to a second embodiment of the present invention is characterized in that the molding portion (14) includes a phase change material. Here, the molding portion may be composed of an overlapping molding portion including a first molding (17) and a second molding (18).

[0053] Phase change materials refer to materials that can absorb or release a large amount of heat by changing their form from solid to liquid, liquid to gas, or vice versa at a specific temperature without a change in temperature; they are materials that function as latent heat sources, heat storage materials, or thermal regulators, storing ambient heat on their own and releasing it when needed.

[0054] Phase change materials that undergo phase changes at various temperatures can be classified into organic materials, inorganic materials, and plant materials obtainable from nature. The phase change materials mentioned in this specification may be applied such that the temperature at which the phase change occurs varies depending on ambient conditions.

[0055] For example, based on a range of approximately 0°C to 25°C, organic powder-type alkane hydrocarbon compounds protected by microcapsules may be used for low temperature conditions below freezing. Specifically, dodecane, tridecane, tetradecane, pentadecane, etc. may be used.

[0056] Under high temperature conditions exceeding 25°C, inorganic powder-type manganese nitrate hexahydrate (Mn(NO3)2·6H2O), manganese nitrate tetrahydrate (Mn(NO3)2·4H2O), zinc nitrate hexahydrate (Zn(NO3)2·6H2O), sodium sulfate decihydrate (Na2SO4·10H2O), sodium acetate trihydrate (CH3COONa3·H2O), etc. may be used.

[0057] In the electronic voltage sensor (10) according to the second embodiment of the present invention, a molding part (14) may be formed by mixing a corresponding phase change material according to the target with low temperature conditions and high temperature conditions so that the release of heat absorption or latent heat regarding the temperature around the voltage sensor occurs smoothly.

[0058] To this end, the molding portion (14) of the electronic voltage sensor (10) according to the second embodiment of the present invention can be formed by stirring a molding material containing a phase change material according to a target temperature condition, and then using a mold to overlap the molding material with a certain thickness on a pair of stacked electrodes (11, 12) and an insulator (13).

[0059] For example, first, a first molding (17) can be formed by molding a molding material containing a first phase change material corresponding to low temperature conditions, such as an organic powder-type alkane hydrocarbon compound, to a certain thickness for a stacked pair of electrodes (11, 12) and an insulator (13).

[0060] Next, a second molding (18) can be formed by molding a molding material containing a second phase change material corresponding to high temperature conditions, such as an inorganic powder type hydrate, to a certain thickness with respect to a pair of electrodes (11, 12) and an insulator (13) molded by the first molding (17). Thus, the second molding can be molded while surrounding the first molding in which the pair of electrodes and the insulator are embedded.

[0061] Alternatively, the molding portion (14) may be formed in the opposite way. In other words, after forming the first molding (17) with a molding material containing, for example, an inorganic powder type hydrate corresponding to high temperature conditions, the second molding (18) may be formed with a molding material containing, for example, an organic powder type alkane hydrocarbon compound corresponding to low temperature conditions. Thus, the second molding can be molded while surrounding the first molding in which a pair of electrodes (11, 12) and an insulator (13) are embedded.

[0062] In the electronic voltage sensor (10) according to the second embodiment of the present invention, the molding portion (14) may include a first molding (17) and a second molding (18) that are superimposed, and the first molding in which a pair of electrodes (11, 12) and an insulator (13) are embedded may be formed by being embedded within the second molding.

[0063] Additionally, the first molding (17) may be formed from a molding material containing a first phase change material, and the second molding (18) may be formed from a molding material containing a second phase change material. Here, the first phase change material and the second phase change material have different temperature conditions and may react according to the corresponding temperature conditions.

[0064] Specifically, under low temperature conditions, either the first phase change material of the first molding (17) or the second phase change material of the second molding (18) undergoes an exothermic reaction, and under high temperature conditions, the other of the first phase change material of the first molding (17) and the second phase change material of the second molding (18) undergoes an endothermic reaction.

[0065] Accordingly, the electronic voltage sensor (10) according to the second embodiment of the present invention can respond to temperature changes in both low temperature and high temperature conditions with a single voltage sensor.

[0066] As described above, according to the second embodiment of the present invention, the phase change material molded into the electronic voltage sensor undergoes an endothermic or exothermic reaction to temperature changes occurring, for example, outside and / or inside the tank of the GIS, thereby maintaining the output of the voltage sensor constant or minimizing changes in output.

[0067] For example, when an electronic voltage sensor is applied to a device in an atmosphere of insulating gas such as GIS, the change in the value of C2 (the second capacitance [F] possessed by the voltage sensor itself) of the voltage sensor due to temperature change can be minimized, thereby maintaining the constancy of the value of C2 output from the voltage sensor regardless of temperature change.

[0068] Accordingly, according to the second embodiment of the present invention, the effect of satisfying high precision and non-error performance of a low-power instrument transformer employing an electronic voltage sensor is obtained.

[0069] The above description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention.

[0070] Accordingly, the embodiments disclosed in this invention are intended to explain, not limit, the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments. The scope of protection of this invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this invention.

[0071] The present invention is useful, for example, for providing an electronic transformer for low-power instruments with improved precision.

Claims

1. A pair of electrodes formed in a ring shape to allow a conductor to pass through and arranged concentrically; A ring-shaped insulator concentrically disposed between the above pair of electrodes; and A molded part that integrates the stacked pair of electrodes and the insulator by molding them together. Includes, The above-mentioned molding part is a voltage sensor containing a phase change material.

2. In Paragraph 1, The above-mentioned phase change material is a voltage sensor comprising at least one of organic materials, inorganic materials, and plant materials obtainable from nature.

3. In Paragraph 1, The above phase change material is a voltage sensor comprising an organic material that releases heat stored in the form of latent heat under temperature conditions below a predetermined range.

4. In Paragraph 3, The above organic material is a voltage sensor made of an organic powder-type alkane hydrocarbon compound protected by microcapsules.

5. In Paragraph 1, The above phase change material is a voltage sensor comprising an inorganic material that absorbs ambient heat under temperature conditions exceeding a predetermined range.

6. In Paragraph 5, The above inorganic material is a voltage sensor in the form of an inorganic powder-type hydrate.

7. In Paragraph 1, The above-described molding part is a voltage sensor formed by stirring the molding material containing the phase change material and then using a mold to mold the stacked pair of electrodes and the insulator with the molding material.

8. In Paragraph 1, The above molding part includes an overlapping first molding and a second molding, and A voltage sensor formed by embedding the first molding, in which the above pair of electrodes and the above insulator are embedded, into the second molding.

9. In Paragraph 8, The first molding is formed by molding the stacked pair of electrodes and the insulator with a molding material containing a first phase change material, and The above second molding is a voltage sensor formed from a molding material containing a second phase change material different from the first phase change material, while surrounding the above first molding.

10. In Paragraph 9, The first phase change material and the second phase change material are voltage sensors with different reaction temperature conditions.

11. In Paragraph 10, Under temperature conditions below a predetermined range, either of the first phase change material and the second phase change material releases heat stored in the form of latent heat, and A voltage sensor in which, under temperature conditions exceeding the above-mentioned predetermined range, the other of the first phase change material and the second phase change material absorbs ambient heat.

12. In any one of paragraphs 1 through 11, The above pair of electrodes includes a first electrode and a second electrode, and A voltage sensor in which the diameter of the insulator is larger than the diameter of the first electrode and smaller than the diameter of the second electrode, so that the insulator is located inside the second electrode and the first electrode is located inside the insulator.

13. In Paragraph 12, A voltage sensor with signal lines connected to the first electrode and the second electrode, respectively.

14. In Paragraph 12, The above insulator is a voltage sensor having a width greater than the width (axial length) of the above pair of electrodes.

15. In any one of paragraphs 1 through 11, The above voltage sensor is a voltage sensor that measures the voltage flowing through the conductor using the capacitance voltage division principle.

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