Device and method for measuring non-contact voltage of distribution station area based on impedance conversion

Abstract

The invention discloses a non-contact voltage measurement device and method for a distribution station area based on impedance conversion, and relates to the technical field of voltage measurement of the distribution station area, and the key points of the technical scheme are as follows: a double-coupling mechanism probe is adopted to eliminate the influence of coupling capacitance change on line voltage measurement; and a shielding cover is added to eliminate the capacitance of the outer copper pole to the ground and the capacitance of the line to the outer copper pole, the number of unknown capacitors in an equivalent circuit diagram is reduced, and non-contact voltage measurement of line voltage is screened through impedance conversion.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage measurement in a distribution station area, and more specifically, to a non-contact voltage measurement device and method for a distribution station area based on impedance transformation. Background Art

[0002] Voltage measurement is an important part of power system operation. It has a significant impact on power metering, relay protection, and automation equipment control. Ensuring its accuracy and reliability is of great significance to the safe operation of the power grid and the development of smart grids.

[0003] Compared with traditional contact voltage measurement, non-contact voltage measurement devices avoid a series of insulation problems because they have no direct electrical connection with the line. Non-contact voltage sensors are small in size and have the advantages of easy installation and maintenance, and can be widely deployed. Although the prior art records the use of a response equation of a dual-path coupling mechanism to eliminate the changing capacitance to the ground, so that the measuring device can adaptively match the changing measurement conditions. However, it does not take into account that the capacitance of the outer copper pole of the line and the capacitance of the outer copper pole to the ground are greatly affected by the environment, and the voltage measurement process is more complicated.

[0004] Therefore, how to study and design a non-contact voltage measurement device and method for a distribution station area based on impedance transformation that can overcome the above-mentioned defects is a problem that we urgently need to solve. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a non-contact voltage measurement device and method for a distribution station area based on impedance transformation. The present invention adopts a dual coupling mechanism probe to eliminate the influence of coupling capacitance changes on line voltage measurement, and adds a shielding cover to eliminate the capacitance of the outer copper pole to the ground and the capacitance of the line to the outer copper pole, thereby reducing the number of unknown capacitances in the equivalent circuit diagram, and screens the line voltage through impedance transformation for non-contact voltage measurement.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] In a first aspect, a non-contact voltage measurement device for a distribution station area based on impedance transformation is provided, comprising a dual coupling mechanism probe composed of a first coupling mechanism and a second coupling mechanism;

[0008] The first coupling mechanism and the second coupling mechanism both include an inner copper pole and an outer copper pole that are spaced apart, and the relative dielectric constant of the medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is different from that of the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism;

[0009] The outer layer of the dual coupling mechanism probe is provided with a shielding cover, and the shielding cover is grounded;

[0010] The device measures the inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism, and obtains the line voltage of the non-contact voltage measurement based on the reverse analysis of impedance transformation.

[0011] Furthermore, the medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is polyvinyl chloride;

[0012] Furthermore, the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism is air.

[0013] Furthermore, the inner copper pole and the outer copper pole in the first coupling mechanism and / or the second coupling mechanism have the same length, and the inner copper pole and the outer copper pole are two cylindrical copper poles with a radius difference of 4 mm.

[0014] In a second aspect, a non-contact voltage measurement method for a distribution station area based on impedance transformation is provided, comprising the following steps:

[0015] According to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the distribution station area based on impedance transformation described in any one of the first aspects, the field problem is converted into a circuit relationship to determine the initial equivalent circuit of the sensor when it is online;

[0016] The circuit-to-external copper inter-electrode capacitance and the external copper electrode-to-ground capacitance in the initial equivalent circuit are filtered to obtain the final equivalent circuit;

[0017] Based on the impedance transformation principle, the final equivalent circuit is reversely analyzed to obtain the equation model of the line voltage and response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole.

[0018] The measured inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism are input into the equation model to solve and obtain the line voltage of the non-contact voltage measurement.

[0019] Furthermore, the inter-electrode voltage between the inner copper electrode and the outer copper electrode is measured using the capacitive voltage division principle.

[0020] Furthermore, the inter-electrode capacitance between the inner copper electrode and the outer copper electrode is measured using a digital bridge.

[0021] Furthermore, the expression of the equation model is specifically:

[0022]

[0023] Among them, U Arepresents the line voltage of non-contact voltage measurement; C2 represents the inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism; C3 represents the inter-electrode capacitance between the inner copper pole and the outer copper pole in the second coupling mechanism; u1 represents the inter-electrode voltage between the inner copper pole and the outer copper pole in the first coupling mechanism; u2 represents the inter-electrode voltage between the inner copper pole and the outer copper pole in the second coupling mechanism.

[0024] In a third aspect, a non-contact voltage measurement system for a distribution station area based on impedance transformation is provided, and the system is used to implement the non-contact voltage measurement method for a distribution station area based on impedance transformation as described in any one of the second aspects, comprising the following steps:

[0025] An initial equivalent module, for converting the field problem into a circuit relationship according to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the distribution station area based on impedance transformation described in any one of the first aspects, and determining the initial equivalent circuit of the sensor when it is online;

[0026] An equivalent optimization module is used to filter the capacitance between the lines and the external copper poles and the capacitance between the external copper poles and the ground in the initial equivalent circuit to obtain a final equivalent circuit;

[0027] The reverse analysis module is used to reversely analyze the final equivalent circuit based on the impedance transformation principle to obtain the equation model of the line voltage and the response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole;

[0028] The voltage solving module is used to input the measured inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism into the equation model to solve and obtain the line voltage of the non-contact voltage measurement.

[0029] In a fourth aspect, a computer terminal is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a non-contact voltage measurement method for a distribution station area based on impedance transformation as described in any one of the second aspects is implemented.

[0030] In a fifth aspect, a computer-readable medium is provided, on which a computer program is stored, and the computer program is executed by a processor to implement the non-contact voltage measurement method for a distribution station area based on impedance transformation as described in any one of the second aspects.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention adopts a dual-coupling mechanism probe to eliminate the influence of coupling capacitance change on line voltage measurement, and adds a shielding cover to eliminate the capacitance of the outer copper pole to the ground and the capacitance of the line to the outer copper pole, thereby reducing the number of unknown capacitances in the equivalent circuit diagram, and screens the line voltage through impedance transformation for non-contact voltage measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0034] Figure 1 is a schematic diagram of the installation structure in Embodiment 1 of the present invention;

[0035] Figure 2 is a schematic diagram of an initial equivalent circuit in Embodiment 2 of the present invention;

[0036] Figure 3 is a schematic structural diagram of a dual coupling mechanism probe in Embodiment 2 of the present invention;

[0037] Figure 4 is a schematic diagram of the final equivalent circuit in Embodiment 2 of the present invention;

[0038] Figure 5 This is a system block diagram in Example 3 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0040] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component.

[0041] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0043] Embodiment 1: A non-contact voltage measuring device for a matching radio area based on impedance transformation, such as Figure 1 and Figure 3 As shown, a dual-coupling mechanism probe is comprised of a first coupling mechanism and a second coupling mechanism. The first coupling mechanism and the second coupling mechanism both include an inner copper pole and an outer copper pole that are spaced apart, and the relative dielectric constant of the medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is different from that of the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism; the outer layer of the dual-coupling mechanism probe is provided with a shielding cover, and the shielding cover is grounded.

[0044] The device measures the inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism, and obtains the line voltage of the non-contact voltage measurement based on the reverse analysis of impedance transformation.

[0045] It should be noted that the medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is polyvinyl chloride, and the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism is air. Other safe media with different relative dielectric constants can also be used without limitation.

[0046] In addition, the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism have the same length, and the inner copper pole and the outer copper pole are two cylindrical copper poles with a radius difference of 4 mm.

[0047] Embodiment 2: A non-contact voltage measurement method for a radio area based on impedance transformation is implemented by the following steps.

[0048] Step 1: According to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the matching radio area based on impedance transformation recorded in Example 1, the field problem is converted into a circuit relationship to determine the initial equivalent circuit when the sensor is online.

[0049] like Figure 2 As shown, according to the positional relationship between the line and the voltage sensor, the line and the probe can be equivalent to a coupling capacitor. Taking the first coupling mechanism as an example, let the coupling capacitor between the line and the inner copper pole be C1, the coupling capacitor between the inner copper pole and the outer copper pole be C2, the coupling capacitor between the outer copper pole and the earth be C5, and the coupling capacitor between the line and the outer copper pole be C4.

[0050] Due to the changeable environment of the transmission lines in the distribution area, changes in temperature and humidity in the air will affect multiple unknown coupling capacitors between the lines and sensors. In order to adapt to various environments and eliminate the impact of coupling capacitor changes on line voltage measurement, the present invention adopts a dual coupling mechanism probe. The inner and outer copper electrodes of the two coupling mechanisms are equal in size. The difference is that the inner and outer copper electrodes of the left mechanism are air, and the inner and outer copper electrodes of the right mechanism are polyvinyl chloride with a relative dielectric constant of 4.

[0051] Considering the coupling capacitance between the two coupling mechanisms, it can be seen that the coupling capacitance between the line and the inner copper pole in the two coupling mechanisms is equal, that is, C1. The capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism is recorded as C2, and the capacitance between the inner copper pole and the outer copper pole in the second coupling mechanism is recorded as C3. The voltages between the inner and outer copper poles of the two coupling mechanisms are different, thereby realizing non-contact voltage measurement with impedance transformation.

[0052] Step 2: Filter the capacitance between the lines and the external copper poles and the capacitance between the external copper poles and the ground in the initial equivalent circuit to obtain the final equivalent circuit.

[0053] Since the capacitance of the line to the external copper pole and the capacitance of the external copper pole to the ground are unknown and greatly affected by the environment, a shielding cover is added to the outer layer of the double coupling mechanism probe. By grounding the shielding cover, the capacitance between the line and the external copper pole and the capacitance of the external copper pole to the ground can be ignored in the equivalent circuit diagram, such as Figure 4 shown.

[0054] Step 3: Based on the impedance transformation principle, the final equivalent circuit is reversely analyzed to obtain the equation model of the line voltage and response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole.

[0055] On the basis of steps one and two, the principle of capacitive voltage division is used to reverse the line voltage by measuring the voltage between the inner and outer copper electrodes (u1, u2) of the left and right coupling mechanisms (the left coupling mechanism is the first coupling mechanism, and the right coupling mechanism is the second coupling mechanism). The equivalent circuit is as follows: Figure 4 As shown, the specific equation is as follows:

[0056]

[0057] Where ω is the frequency of the line under different working conditions; U A is the line voltage.

[0058] The digital bridge can be used to measure the coupling capacitance between the inner and outer copper electrodes in the two coupling mechanisms, so C2 and C3 are known. By combining the two equations in formula (1), the coupling capacitance C1 between the line and the inner copper electrode and the line voltage U can be solved. A The specific solution process is as follows:

[0059]

[0060] C1·(u1-u2)=C3·u2-C2·u1 (3);

[0061]

[0062] Substituting the coupling capacitance C1 between the line and the inner copper electrode into formula (1), the equation model can be obtained:

[0063]

[0064] Step 4: Input the measured inter-electrode voltage and inter-electrode capacitance between the inner copper electrode and the outer copper electrode in the first coupling mechanism and the second coupling mechanism into the equation model, and solve to obtain the line voltage of the non-contact voltage measurement.

[0065] The sensor probe is hung on the line of the distribution station area, and the line voltage U can be measured by substituting the measured voltages u1, u2 and the measured capacitances C2, C3 into equations (4) and (5): A .

[0066] Embodiment 3: A non-contact voltage measurement system for a distribution station area based on impedance transformation, the system is used to implement the non-contact voltage measurement method for a distribution station area based on impedance transformation as described in Embodiment 2, such as Figure 5 As shown, the following steps include initial equivalent module, equivalent optimization module, inverse analysis module and voltage solution module.

[0067] Among them, the initial equivalent module is used to convert the field problem into a path relationship according to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the matching radio area based on impedance transformation recorded in Example 1, and determine the initial equivalent circuit of the sensor when it is online; the equivalent optimization module is used to filter the capacitance between the line and the outer copper pole and the capacitance between the outer copper pole and the ground in the initial equivalent circuit to obtain the final equivalent circuit; the reverse analysis module is used to perform reverse analysis on the final equivalent circuit based on the impedance transformation principle to obtain the equation model of the line voltage and the response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole; the voltage solving module is used to input the measured inter-pole voltage and inter-pole capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism into the equation model to solve and obtain the line voltage of the non-contact voltage measurement.

[0068] The present invention also records a computer terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the non-contact voltage measurement method for the distribution station area based on impedance transformation as described in Example 2 is implemented.

[0069] The present invention also describes a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the non-contact voltage measurement method for a matching radio area based on impedance transformation as described in Example 2.

[0070] Working principle: The present invention adopts a dual-coupling mechanism probe to eliminate the influence of coupling capacitance changes on line voltage measurement, and adds a shielding cover to eliminate the capacitance of the outer copper pole to the ground and the capacitance of the line to the outer copper pole, reducing the number of unknown capacitances in the equivalent circuit diagram, and screens the line voltage through impedance transformation for non-contact voltage measurement.

[0071] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0072] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0073] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0074] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0075] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A non-contact voltage measuring device for a radio area based on impedance transformation, characterized in that: A dual coupling mechanism probe including a first coupling mechanism and a second coupling mechanism; The first coupling mechanism and the second coupling mechanism both include an inner copper pole and an outer copper pole that are spaced apart, and the relative dielectric constant of the medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is different from that of the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism; The outer layer of the dual coupling mechanism probe is provided with a shielding cover, and the shielding cover is grounded; The device measures the inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism, and obtains the line voltage of the non-contact voltage measurement based on the reverse analysis of impedance transformation.

2. The non-contact voltage measuring device for a distribution area based on impedance transformation according to claim 1 is characterized in that: The medium filled between the inner copper pole and the outer copper pole in the first coupling mechanism is polyvinyl chloride; Furthermore, the medium filled between the inner copper pole and the outer copper pole in the second coupling mechanism is air.

3. The non-contact voltage measuring device for a distribution area based on impedance transformation according to claim 1 is characterized in that: The inner copper pole and the outer copper pole in the first coupling mechanism and / or the second coupling mechanism have the same length, and the inner copper pole and the outer copper pole are two cylindrical copper poles with a radius difference of 4 mm.

4. A non-contact voltage measurement method for a radio area based on impedance transformation, characterized in that: The following steps are involved: According to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the distribution area based on impedance transformation according to any one of claims 1-3, the field problem is converted into a circuit relationship to determine the initial equivalent circuit of the sensor when it is online; The circuit in the initial equivalent circuit is filtered to obtain the capacitance between the external copper poles and the capacitance between the external copper poles and the ground, thereby obtaining the final equivalent circuit; Based on the impedance transformation principle, the final equivalent circuit is reversely analyzed to obtain the equation model of the line voltage and response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole. The measured inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism are input into the equation model to solve and obtain the line voltage of the non-contact voltage measurement.

5. The non-contact voltage measurement method based on impedance transformation in a distribution station area according to claim 1 is characterized in that: The inter-electrode voltage between the inner copper electrode and the outer copper electrode is measured using the capacitance voltage division principle.

6. The non-contact voltage measurement method based on impedance transformation in a distribution station area according to claim 1 is characterized in that: The inter-electrode capacitance between the inner copper electrode and the outer copper electrode is measured using a digital bridge.

7. The non-contact voltage measurement method based on impedance transformation in a distribution station area according to claim 1 is characterized in that: The expression of the equation model is specifically: Among them, U A represents the line voltage of non-contact voltage measurement; C2 represents the inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism; C3 represents the inter-electrode capacitance between the inner copper pole and the outer copper pole in the second coupling mechanism; u1 represents the inter-electrode voltage between the inner copper pole and the outer copper pole in the first coupling mechanism; u2 represents the inter-electrode voltage between the inner copper pole and the outer copper pole in the second coupling mechanism.

8. A non-contact voltage measurement system for a distribution area based on impedance transformation, characterized in that: The system is used to implement the non-contact voltage measurement method based on impedance transformation in the distribution station area as described in any one of claims 4 to 7, comprising the following steps: An initial equivalent module is used to convert the field problem into a circuit relationship according to the coupling relationship between the line and the inner copper pole and the outer copper pole in the non-contact voltage measurement device for the distribution area based on impedance transformation according to any one of claims 1 to 3, and determine the initial equivalent circuit of the sensor when it is online; An equivalent optimization module is used to filter the capacitance between the lines and the external copper poles and the capacitance between the external copper poles and the ground in the initial equivalent circuit to obtain a final equivalent circuit; The reverse analysis module is used to reversely analyze the final equivalent circuit based on the impedance transformation principle to obtain the equation model of the line voltage and the response voltage before and after the impedance transformation between the inner copper pole and the outer copper pole; The voltage solving module is used to input the measured inter-electrode voltage and inter-electrode capacitance between the inner copper pole and the outer copper pole in the first coupling mechanism and the second coupling mechanism into the equation model to solve and obtain the line voltage of the non-contact voltage measurement.

9. A computer terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the non-contact voltage measurement method based on impedance transformation in the distribution station area as described in any one of claims 4 to 7 is implemented.

10. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the non-contact voltage measurement method for a distribution station area based on impedance transformation as described in any one of claims 4 to 7.

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