JP2018081775A - Method, program and system for detecting state of gas discharge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, a program and a system for detecting a state of gas discharge, allowing for detection of the state of gas discharge.SOLUTION: The method for detecting a state of gas discharge of the embodiment includes: measuring a potential appearing in a circuit electrically connected to a conductor by electrostatic induction between the gas discharge and the conductor; and calculating, based on the measured potential and a physical property value of the circuit, the potential of the gas discharge.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a gas discharge state detection method, a gas discharge state detection program, and a gas discharge state detection system.

Gas discharges are generated in various electrical devices such as power transmission and transformation equipment such as gas circuit breakers and vacuum circuit breakers, fluorescent lamps, ozone generators, in-vehicle relays, and automobile fuses.
However, it is often difficult to detect the state of gas discharge.

M.WEUFFEL, P.G.NIKOLIC AND A.SCHNETTLER, “INVESTIGATIONS ON THE SPATIAL ARC RESISTANCE DISTRIBUTION OF AN AXIALLY BLOWN SWITCHING ARC”, 20th International Conference on Gas Discharges and their Applications, 6-11 July 2014, France, p.155-158

  The problem to be solved by the present invention is to provide a gas discharge state detection method, a gas discharge state detection program, and a gas discharge state detection system capable of detecting a gas discharge state.

  In the gas discharge state detection method according to the embodiment, the potential appearing in a circuit electrically connected to the conductor is measured by electrostatic induction between the gas discharge and the conductor, and the measured potential and the physical property of the circuit are measured. And calculating a potential of the gas discharge based on the value.

The figure which shows the state detection system of the gas discharge of 1st Embodiment. The block diagram which shows the function structure inside the computer of 1st Embodiment. The block diagram which shows the equivalent circuit of 1st Embodiment. The flowchart which shows an example of the processing flow of 1st Embodiment. The figure which shows the state detection system of the gas discharge of 2nd Embodiment. The figure which shows the state detection system of the gas discharge of 3rd Embodiment. The figure which shows the state detection system of the gas discharge of 4th Embodiment. The figure which shows the state detection system of the gas discharge of 5th Embodiment. The figure which shows the state detection system of the gas discharge of 6th Embodiment. The block diagram which shows the equivalent circuit of 6th Embodiment. The figure which shows the case where two conductors are arrange | positioned in parallel. The flowchart which shows an example of the processing flow of 6th Embodiment. The figure which shows the state detection system of the gas discharge of the 1st modification of 6th Embodiment. The figure which shows the state detection system of the gas discharge of the 2nd modification of 6th Embodiment. The figure which shows the state detection system of the gas discharge of 7th Embodiment. The figure which shows the state detection system of the gas discharge of 8th Embodiment. Sectional drawing which shows the state detection system of the gas discharge of 9th Embodiment. The figure which shows the state detection system of the gas discharge of 10th Embodiment. The flowchart which shows an example of the processing flow of 10th Embodiment.

  Hereinafter, a gas discharge state detection method, a gas discharge state detection program, and a gas discharge state detection system according to embodiments will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. And the overlapping description of these structures may be omitted.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 4.
FIG. 1 is a diagram illustrating a gas discharge state detection system 1 (hereinafter simply referred to as “detection system 1”) according to a first embodiment. FIG. 1A is a cross-sectional view showing the detection system 1. (B) in FIG. 1 is a cross-sectional view taken along line F1b-F1b of the detection system 1 shown in (a) in FIG.

Here, first, an example of the electric device 10 to which the detection system 1 is applied will be described.
As shown in FIG. 1, the electric device 10 includes a power source 11, a first discharge electrode 12, a second discharge electrode 13, and a switch 14. The power source 11 is a DC power source, for example, but may be an AC power source. The first discharge electrode 12 is electrically connected to the first side (for example, the positive electrode side) of the power source 11. The second discharge electrode 13 is electrically connected to the second side (for example, the negative electrode side) of the power source 11. The switch 14 is provided, for example, between the power supply 11 and the first discharge electrode 12 and switches the electrical connection state between the power supply 11 and the first discharge electrode 12.

  In the electrical device 10, when the switch 14 is turned on, a gas discharge P is generated between the first discharge electrode 12 and the second discharge electrode 13. The gas discharge P has a resistance distribution. For this reason, a potential distribution exists in the gas discharge P itself. In the gas discharge P, for example, when an instantaneous current value such as an alternating current changes or a circuit is interrupted, a state change such as attenuation of the gas discharge P occurs. Examples of the state change include a change in the potential distribution in the axial direction Z of the gas discharge P, a change in the discharge diameter (arc diameter) D of the gas discharge P, and a change in the position in the radial direction R of the gas discharge P. The “discharge diameter D of the gas discharge P” means the diameter of the gas discharge P (the diameter of the ionized portion) in the radial direction R of the gas discharge P. The discharge diameter D may be referred to as “effective ionization diameter”, for example.

  Here, “the central axis C of the gas discharge P”, “the axial direction Z of the gas discharge P”, “the radial direction R of the gas discharge P”, and “the circumferential direction θ of the gas discharge P” are defined. A central axis C of the gas discharge P is a central axis extending in a direction from the first discharge electrode 12 toward the second discharge electrode 13. The gas discharge P may be displaced in the radial direction R. The central axis C referred to here is a central axis connecting the central portion of the first discharge electrode 12 and the central portion of the second discharge electrode 13. It is. The axial direction Z of the gas discharge P is a direction along the central axis C. The radial direction R of the gas discharge P is a direction radially away from the central axis C or the opposite direction. The circumferential direction θ of the gas discharge P is a direction rotating around the central axis C. Hereinafter, “the axial direction Z of the gas discharge P”, “the radial direction R of the gas discharge P”, and “the circumferential direction θ of the gas discharge P” are simply referred to as “axial direction Z”, “radial direction R”, and It may be referred to as “circumferential direction θ”.

Next, the detection system 1 of this embodiment will be described.
The detection system 1 is a system that detects the state of the gas discharge P in a non-contact manner. The detection system 1 according to the present embodiment includes a detection conductor 21 disposed around the gas discharge P, and is guided to the detection conductor 21 by the capacitance between the gas discharge P and the detection conductor 21. This is a system for calculating the potential of the gas discharge P based on the electric charge.

  As shown in FIG. 1, the detection system 1 includes a detection conductor 21, a plurality of ground conductors 22, a coaxial cable 23, a waveform measuring device 24, and a computer 25.

  The detection conductor 21 is disposed around the gas discharge P. The detection conductor 21 is an example of a “conductor”. The detection conductor 21 is arranged as a position in the axial direction Z of the gas discharge P at a position corresponding to the measurement target site Pt of the gas discharge P. That is, the detection conductor 21 faces the measurement target site Pt of the gas discharge P in the radial direction R of the gas discharge P. In the present embodiment, the detection conductor 21 is formed in an annular shape (for example, a cylindrical shape) surrounding the gas discharge P. The gas discharge P and the detection conductor 21 are electrically insulated by, for example, gas. For this reason, a capacitance is formed between the gas discharge P and the detection conductor 21. Electric charges are induced in the detection conductor 21 by electrostatic induction between the gas discharge P and the detection conductor 21, and a potential is induced.

  Each of the plurality of ground conductors 22 is disposed around the gas discharge P. Each of the plurality of ground conductors 22 is arranged as a position in the axial direction Z of the gas discharge P so as to correspond to a part different from the measurement target part Pt in the gas discharge P. Each of the plurality of ground conductors 22 is grounded and has a ground potential. Each of the plurality of ground conductors 22 has, for example, substantially the same shape as the detection conductor 21 and is formed in an annular shape (for example, a cylindrical shape) surrounding the gas discharge P.

  In the present embodiment, the plurality of ground conductors 22 include a first ground conductor 22A and a second ground conductor 22B. The first ground conductor 22 </ b> A is located closer to the first discharge electrode 12 than the detection conductor 21. The first grounding conductor 22A is adjacent to the detection conductor 21 in the axial direction Z of the gas discharge P. The first ground conductor 22 </ b> A covers the first end Pa of the gas discharge P and the first discharge electrode 12 in the radial direction R of the gas discharge P. On the other hand, the second ground conductor 22 </ b> B is located closer to the second discharge electrode 13 than the detection conductor 21. The second ground conductor 22B is adjacent to the detection conductor 21 from the opposite side to the first ground conductor 22A in the axial direction Z of the gas discharge P. The second ground conductor 22 </ b> B covers the second end portion Pb of the gas discharge P and the second discharge electrode 13 in the radial direction R of the gas discharge P.

  The coaxial cable 23 extends between the detection conductor 21 and the waveform measuring device 24. The coaxial cable 23 electrically connects the detection conductor 21 and the waveform measuring device 24.

  The waveform measuring instrument 24 is an example of a “measurement unit”. The waveform measuring instrument 24 has an internal circuit 24 a that is connected to the coaxial cable 23 and measures a potential. When the electric charge is induced in the detection conductor 21 by electrostatic induction between the gas discharge P and the detection conductor 21, the waveform measuring device 24 is connected to the internal circuit 24 a based on the electric charge induced in the detection conductor 21. Measure the potential that appears. From a certain viewpoint, the coaxial cable 23 and the internal circuit 24 a of the waveform measuring device 24 form one circuit (measurement circuit) 31 electrically connected to the detection conductor 21. The waveform measuring device 24 measures the potential appearing in the circuit 31 based on the charge induced in the detection conductor 21. The term “circuit” as used in the present application means a wide current path, and is not limited to a circuit in which a current flows in a loop. Further, “detecting” or “measuring” as used in the present application includes not only directly detecting or measuring, but also indirectly detecting or measuring via another element.

  The computer 25 is connected to the waveform measuring device 24 by wire or wirelessly, and receives a measurement result measured by the waveform measuring device 24 from the waveform measuring device 24. Instead of the above example, the computer 25 may receive the measurement result of the waveform measuring device 24 via a storage medium or other means. The computer 25 includes a processor 41 such as a CPU (Central Processor Unit), and a storage unit 42 that stores programs and various numerical values.

FIG. 2 is a block diagram showing an internal functional configuration of the computer 25.
As illustrated in FIG. 2, the computer 25 includes a storage unit 42, an information acquisition unit 45, a calculation unit 46, and an information output unit 47.

The storage unit 42 is, for example, a hard disk drive (HDD) or a semiconductor memory. The storage unit 42 stores information related to circuit equations described later, the value of the capacitance C ₀₁ , the physical property value of the circuit 31, and the like. The “physical property value of the circuit 31” is a value determined by, for example, the physical property value of the coaxial cable 23 and the physical property value of the internal circuit 24a of the waveform measuring instrument 24. In the present embodiment, the storage unit 42 stores physical property values of the coaxial cable 23, physical property values of the internal circuit 24 a of the waveform measuring device 24, and the like as physical property values of the circuit 31.

The information acquisition unit 45 acquires the measurement result of the waveform measuring instrument 24.
The calculator 46 calculates the potential of the measurement target site Pt of the gas discharge P based on the potential measured by the waveform measuring instrument 24 and the physical property value of the circuit 31. A method for calculating the potential of the gas discharge P will be described later in detail.
The information output unit 47 outputs the result calculated by the calculation unit 46. The information output unit 47 may be a display unit having a screen, or may be an output unit that outputs a result calculated by the calculation unit 46 to an external device, a network, a storage medium, or the like.

Next, the detection method of the gas discharge P using the detection system 1 of this embodiment is demonstrated.
In the present embodiment, the potential of the gas discharge P is calculated based on the potential measured by the waveform measuring instrument 24 and the physical property value of the circuit 31. As used herein, “based on OO” means “based on at least OO”. That is, “based on ○” includes the case where it is based on another element in addition to ○○. For example, in the present embodiment, an equivalent circuit 51 (see FIG. 3) including the capacitance between the gas discharge P and the detection conductor 21 and the circuit 31 is derived, and the potential measured by the waveform measuring device 24 is Based on the physical property value of the circuit 31 and the equivalent circuit 51, the potential of the gas discharge P is calculated. Hereinafter, this content will be described in detail.

<Derivation of equivalent circuit>
FIG. 3 shows an equivalent circuit 51 including a circuit 31 and a capacitance between the gas discharge P and the detection conductor 21 (capacitance between the measurement target portion Pt of the gas discharge P and the detection conductor 21). FIG. In the figure, v _b is the potential of the measurement target site Pt of the gas discharge P, and is the potential of the detection target. C ₀₁ in the figure is the capacitance between the measurement target site Pt of the gas discharge P and the detection conductor 21. L _c in the figure is the inductance of the coaxial cable 23. C _c in the figure is the capacitance of the coaxial cable 23. _{C DL} in the figure, the capacitance of the internal circuit 24a of the waveform measuring instrument 24. R _DL in the figure is the resistance of the internal circuit 24 a of the waveform measuring instrument 24. V _m1 in the figure is a potential that appears in the circuit 31 and is measured by the waveform measuring instrument 24.

Here, the values of the inductance L _c and the capacitance C _c of the coaxial cable 23 can be known by actual measurement. The values of the capacitance C _DL and the resistance R _DL of the internal circuit 24 a of the waveform measuring device 24 can be known from the instruction manual of the waveform measuring device 24 and the like. Further, the potential V _m1 can be known from the measurement result of the waveform measuring device 24.

On the other hand, the capacitance C ₀₁ between the measurement target site Pt of the gas discharge P and the detection conductor 21 and the potential v _b of the measurement target site Pt of the gas discharge P are unknown values. In the present embodiment, by assuming a capacitance C ₀₁ between the measurement target site Pt of the gas discharge P and the detection conductor 21, the assumed capacitance C ₀₁ is measured by the waveform measuring device 24. The potential v _b of the measurement target site Pt of the gas discharge P is calculated by solving the circuit equation of the equivalent circuit 51 based on the measured potential and the physical property value of the circuit 31.

<Assumption of Capacitance C ₀₁ >
As a method for assuming the capacitance C ₀₁ , for example, there are (1) a method assumed by light emission observation and the like (2) a method assumed by discharge simulation. (1) The method assumed by light emission observation is the measurement of the gas discharge P by observing the discharge diameter D of the measurement target site Pt of the gas discharge P by light emission observation in an actual electrical device 10 or a simulated test facility. In this method, the capacitance C ₀₁ is assumed based on the distance between the target portion Pt and the detection conductor 21 and the dielectric constant of the substance filling the gap between the gas discharge P and the detection conductor 21. On the other hand, (2) the method assumed by the discharge simulation is that a discharge simulation is performed based on the potential difference between the first discharge electrode 12 and the second discharge electrode 13, etc., so that the discharge diameter of the measurement target site Pt of the gas discharge P is This is a method of obtaining the simulation result of D and assuming the capacitance C ₀₁ based on the simulation result of the discharge diameter D and the dielectric constant of the substance filling the gap between the gas discharge P and the detection conductor 21. Note that the method of assuming the capacitance C ₀₁ is not limited to the above example.

ここで、ｉは、回路３１に流れる電流である。ｔは、時刻である。 <Calculation of circuit equation>
Based on the equivalent circuit 51, the potential v _b of stbm Pt of gas discharge P can be represented by the circuit equations of the formula (1).

Here, i is a current flowing through the circuit 31. t is the time.

なお、時刻０ｍｓにおいて、各キャパシタにおける電荷は０Ｃ、電流ｉは０Ａである。 Further, the current i can be expressed by Expression (2).

At time 0 ms, the charge in each capacitor is 0 C and the current i is 0 A.

Then, by substituting Equation (2) into Equation (1), the potential v _b of the measurement target site Pt of the gas discharge P is expressed by the potential v _m1 measured by the waveform measuring device 24 and the capacitance C ₀₁ . Can be represented. Therefore, the potential v _b of the measurement target site Pt of the gas discharge P is calculated by solving the above circuit equation based on the potential v _m1 measured by the waveform measuring instrument 24 and the assumed capacitance C _01. can do.

FIG. 4 is a flowchart showing an example of the processing flow of the present embodiment, and shows an example of the processing flow when the processing is executed by the computer 25, for example. In the present embodiment, information relating to the derived equivalent circuit 51 (for example, a calculation formula for solving a circuit equation of the equivalent circuit 51) is stored in the storage unit 42 of the computer 25 as advance preparation. In addition, the values of the inductance L _c and the capacitance C _c of the coaxial cable 23 are stored in the storage unit 42 of the computer 25 as physical property values of the coaxial cable 23 (physical property values of the circuit 31). The values of the capacitance C _DL and the resistance R _DL of the internal circuit 24a of the waveform measuring device 24 are stored in the storage unit 42 of the computer 25 as the physical property values of the internal circuit 24a of the waveform measuring device 24 (physical property values of the circuit 31). Is done. Further, the assumed value of the capacitance C ₀₁ is stored in the storage unit 42 of the computer 25. Note that some or all of these information and numerical values may be received in the middle of processing instead of being stored in advance.

As shown in FIG. 4, the information acquisition unit 45 acquires the measurement result of the waveform measuring instrument 24 (step S11). The information acquisition unit 45 sends the acquired information to the calculation unit 46. In addition, the calculation unit 46 acquires the physical property value of the circuit 31 from the storage unit 42 (step S12). In addition, the calculation unit 46 acquires the value of the capacitance C ₀₁ from the storage unit 42 (step S13). Further, the calculation unit 46 acquires information on the equivalent circuit 51 (for example, a calculation formula for solving the circuit equation of the equivalent circuit 51) from the storage unit 42 (step S14). Note that the order in which steps S11 to S14 are executed is not limited.

Subsequently, the computing unit 46, based on the information obtained by the step S14 from step S11, and calculates the electric potential _{v b} of stbm Pt gas discharge P (step S15). More specifically, by solving the potential v _m1 measured by the waveform measuring instrument 24, and the physical properties of the circuit 31, based on the capacitance C ₀₁ which is assumed, the circuit equation of the equivalent circuit 51 by numerical calculation Then, the potential v _b of the measurement target site Pt of the gas discharge P is calculated. Then, the calculation unit 46 sends the calculation result to the information output unit 47. The information output unit 47 outputs information received from the calculation unit 46 (step S16).

  According to such a state detection method, the state of the gas discharge P can be detected. That is, for example, gas discharge of industrial equipment usually occurs in a high voltage environment or a high temperature environment. Therefore, in order to ensure safety, gas discharge is often generated in a sealed container. Under such an environment, it is difficult to directly observe the discharge state of the gas discharge.

  On the other hand, the state detection method of the present embodiment measures and measures the potential appearing in the circuit 31 electrically connected to the detection conductor 21 by electrostatic induction between the gas discharge P and the detection conductor 21. Based on the measured potential and the physical property value of the circuit 31, the potential of the gas discharge P is calculated. According to such a method, the potential of the measurement target site Pt of the gas discharge P can be detected in a non-contact manner. For example, according to the present embodiment, it is possible to detect the time variation of the potential of the measurement target site Pt of the gas discharge P without contact.

  In the case of a gas circuit breaker or a vacuum circuit breaker, the current is interrupted at the current zero point of the alternating current. At this time, if the potential distribution of the gas discharge P in the vicinity of the zero point can be known, the gas discharge P can be cut off at a position where it can be cut off more easily. Thereby, the interruption | blocking performance of a gas circuit breaker or a vacuum circuit breaker can be improved.

  In the present embodiment, an equivalent circuit 51 including the capacitance between the gas discharge P and the detection conductor 21 and the circuit 31 is derived, and the measured potential, the physical property value of the circuit 31, and the equivalent circuit 51 Based on the above, the potential of the gas discharge P is calculated. According to such a method, by calculating the potential of the gas discharge P based on the equivalent circuit 51, the potential of the gas discharge P can be calculated with higher accuracy.

  In the present embodiment, the capacitance between the gas discharge P and the detection conductor 21 is assumed, and the measured potential, the physical property value of the circuit 31, the equivalent circuit 51, and the assumed capacitance are obtained. Based on this, the potential of the gas discharge P is calculated. According to such a method, the potential of the gas discharge P can be calculated without providing the correction conductor 71 described in the second embodiment. That is, the potential of the gas discharge P can be calculated with a simpler configuration.

  In the present embodiment, the detection conductor 21 is formed in an annular shape surrounding the gas discharge P. According to such a configuration, even when the gas discharge P is easily displaced in the radial direction R with respect to the central axis C, the calculation error of the potential of the gas discharge P can be reduced. Thereby, the potential of the gas discharge P can be calculated with higher accuracy.

  In the present embodiment, the potential measurement is performed by the waveform measuring device 24 in a state where the ground conductor 22 that is grounded is adjacent to the detection conductor 21 in the axial direction Z of the gas discharge P. According to such a method, it is possible to suppress the potential being induced in the detection conductor 21 from other than the measurement target site Pt of the gas discharge P. Thereby, the potential of the gas discharge P can be calculated with higher accuracy.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in that an insulating container 61 is provided. Configurations other than those described below are the same as those in the first embodiment.

  FIG. 5 is a diagram illustrating a detection system 1 according to the second embodiment. (A) in FIG. 5 is a cross-sectional view showing the detection system 1. (B) in FIG. 5 is a cross-sectional view taken along line F5b-F5b of the detection system 1 shown in (a) in FIG.

  As shown in FIG. 5, the electrical device 10 or the detection system 1 of this embodiment includes an insulating container 61. The insulating container 61 is formed in an annular shape surrounding the gas discharge P. The insulating container 61 is disposed inside the detection conductor 21 and the ground conductor 22 and covers the entire circumference of the gas discharge P. For example, the insulating container 61 has a size extending between the first discharge electrode 12 and the second discharge electrode 13 in the axial direction Z of the gas discharge P. The inner peripheral surface of the insulating container 61 is formed such that the inner space is the narrowest at the central portion in the axial direction Z of the gas discharge P. When such an insulating container 61 is provided, the position of the gas discharge P in the radial direction R is stabilized. For this reason, the potential of the gas discharge P can be calculated with higher accuracy. The insulating container 61 may be realized by a rectifying nozzle (insulating nozzle) such as a gas circuit breaker or a vacuum circuit breaker. The insulating container 61 may be referred to as an “insulating member”.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The present embodiment is different from the first embodiment in that a plurality of detection conductors 21 and a plurality of ground conductors 22 are provided. Configurations other than those described below are the same as those in the first embodiment.

  FIG. 6 is a diagram illustrating a detection system 1 according to the third embodiment. (A) in FIG. 6 is a cross-sectional view showing the detection system 1. (B) in FIG. 6 is a cross-sectional view taken along line F6b-F6b of the detection system 1 shown in (a) in FIG.

As shown in FIG. 6, the detection system 1 of the present embodiment includes a plurality of detection conductors 21 and a plurality of ground conductors 22.
The plurality of detection conductors 21 are separately arranged at different positions in the axial direction Z of the gas discharge P. The plurality of detection conductors 21 are arranged at positions corresponding to the plurality of measurement target portions Pt of the gas discharge P, respectively. In the present embodiment, each of the plurality of detection conductors 21 is formed in an annular shape (for example, a cylindrical shape) surrounding the gas discharge P, similarly to the detection conductor 21 of the first embodiment. The plurality of detection conductors 21 are connected to the waveform measuring device 24 by a coaxial cable 23 independently of each other. The number of detection conductors 21 is not limited to three, and may be two or four or more.

  Each of the plurality of ground conductors 22 is grounded and has a ground potential. Each of the plurality of ground conductors 22 has substantially the same shape as the detection conductor 21 and is formed in an annular shape (for example, a cylindrical shape) surrounding the gas discharge P. In the present embodiment, the plurality of ground conductors 22 include a first ground conductor 22A, a second ground conductor 22B, and a third ground conductor 22C. The first ground conductor 22 </ b> A is located closer to the first discharge electrode 12 than the plurality of detection conductors 21. Among the plurality of detection conductors 21, the first ground conductor 22 </ b> A is in the axial direction Z of the gas discharge P with respect to the detection conductor 21 farthest from the central portion Pc of the gas discharge P toward the first discharge electrode 12. And adjacent to the central portion Pc of the gas discharge P from the opposite side. On the other hand, the second ground conductor 22 </ b> B is located closer to the second discharge electrode 13 than the plurality of detection conductors 21. Among the plurality of detection conductors 21, the second ground conductor 22 </ b> B is in the axial direction Z of the gas discharge P with respect to the detection conductor 21 farthest from the central portion Pc of the gas discharge P toward the second discharge electrode 13. And adjacent to the central portion Pc of the gas discharge P from the opposite side. The third ground conductor 22 </ b> C is disposed between the plurality of detection conductors 21.

  According to such a configuration, by providing the plurality of detection conductors 21, the potentials of the plurality of measurement target portions Pt of the gas discharge P can be calculated. Thereby, the potential distribution in the axial direction Z of the gas discharge P can be obtained. For example, according to the present embodiment, it is possible to detect the time variation of the potentials of the plurality of measurement target sites Pt of the gas discharge P in a non-contact manner.

  In the present embodiment, a first ground conductor 22A and a second ground conductor 22B are provided. Each of the first ground conductor 22A and the second ground conductor 22B is in the axial direction Z of the gas discharge P with respect to the detection conductor 21 farthest from the central portion Pc of the gas discharge P among the plurality of detection conductors 21. And adjacent to the central portion Pc of the gas discharge P from the opposite side. According to such a configuration, it is possible to suppress the potential being induced in the detection conductor 21 from other than the measurement target site Pt of the gas discharge P. Thereby, the potential of the gas discharge P can be detected with higher accuracy.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. This embodiment is different from the third embodiment in that an insulating container 61 is provided. The configurations other than those described below are the same as those in the third embodiment.

  FIG. 7 is a diagram illustrating a detection system 1 according to the fourth embodiment. (A) in FIG. 7 is a sectional view showing the detection system 1. (B) in FIG. 7 is a sectional view taken along line F7b-F7b of the detection system 1 shown in (a) in FIG.

  As illustrated in FIG. 7, the electrical device 10 or the detection system 1 of the present embodiment includes an insulating container 61 as in the second embodiment. According to such a configuration, the position of the gas discharge P in the radial direction R is easily stabilized, and the potentials of the plurality of measurement target portions Pt of the gas discharge P can be calculated with higher accuracy.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIG. This embodiment is different from the fourth embodiment in that the third ground conductor 22C is not provided. The configurations other than those described below are the same as those in the fourth embodiment.

  FIG. 8 is a diagram illustrating a detection system 1 according to the fifth embodiment. (A) in FIG. 8 is a cross-sectional view showing the detection system 1. (B) in FIG. 8 is a cross-sectional view taken along line F8b-F8b of the detection system 1 shown in (a) in FIG.

  As shown in FIG. 8, the detection system 1 of the present embodiment includes a first ground conductor 22A and a second ground conductor 22B. On the other hand, the detection system 1 does not have the third ground conductor 22C. That is, in the present embodiment, the ground conductor 22 is provided only in the end region where the plurality of detection conductors 21 are not adjacent to each other.

  According to such a configuration, the plurality of detection conductors 21 can be arranged at narrow intervals. Therefore, the number of detection conductors 21 provided for the gas discharge P can be increased. Thereby, the potential distribution in the axial direction Z of the gas discharge P can be obtained with higher accuracy.

(Sixth embodiment)
Next, a sixth embodiment will be described with reference to FIGS. This embodiment is different from the first embodiment in that a correction conductor 71 is provided. Configurations other than those described below are the same as those in the first embodiment.

  FIG. 9 is a diagram illustrating a detection system 1 according to the sixth embodiment. (A) in FIG. 9 is a cross-sectional view showing the detection system 1. (B) in FIG. 9 is a sectional view taken along line F9b-F9b of the detection system 1 shown in (a) in FIG.

  As shown in FIG. 9, the detection system 1 of the present embodiment includes a detection conductor 21, a correction conductor 71, a correction capacitor 72, a plurality of ground conductors 22, an insulating container 61, a plurality of coaxial cables 23, and waveform measurement. A device 24 and a computer 25 are provided.

  The detection conductor 21 is an example of a “first conductor”. In the present embodiment, the detection conductor 21 is formed in a rod shape (for example, a cylindrical shape) along the axial direction Z. The shape of the detection conductor 21 is not limited to the above example. The detection conductor 21 may be spherical or other shapes. Similar to the detection conductor 21 of the first embodiment, a charge is induced in the detection conductor 21 by electrostatic induction between the gas discharge P and the detection conductor 21, and a potential is induced.

  The correction conductor 71 is an example of a “second conductor”. The correction conductor 71 has, for example, substantially the same shape as the detection conductor 21. The detection conductor 21 and the correction conductor 71 are disposed corresponding to substantially the same part (the same measurement target part Pt) of the gas discharge P. In other words, the detection conductor 21 and the correction conductor 71 are arranged at substantially the same position as the position in the axial direction Z of the gas discharge P. The detection conductor 21 and the correction conductor 71 are arranged at substantially equal distances with respect to the gas discharge P (with respect to the central axis C of the gas discharge P). For this reason, the electrostatic capacitance between the gas discharge P and the detection conductor 21 and the electrostatic capacitance between the gas discharge P and the correction conductor 71 can be considered to be the same. For example, the correction conductor 71 is disposed on the opposite side of the gas discharge P from the detection conductor 21. The position of the correction conductor 71 is not limited to the above example, and may be a position shifted by 90 ° in the circumferential direction θ with respect to the detection conductor 21 or other positions. Similarly to the detection conductor 21, charges are induced in the correction conductor 71 by electrostatic induction between the gas discharge P and the correction conductor 71, and a potential is induced.

  The correction capacitor 72 is an example of an “electric element (correction electric element)”. The correction capacitor 72 is electrically connected to the correction conductor 71. For example, the correction capacitor 72 is electrically connected to the correction conductor 71 in series. The capacitance of the correction capacitor 72 can be known from catalog values or actual measurements. The electrical element (correction electrical element) electrically connected to the correction conductor 71 is not limited to the correction capacitor 72, and may be a coil, a resistor, or the like.

  The plurality of coaxial cables 23 electrically connect the detection conductor 21 and the correction conductor 71 to the waveform measuring instrument 24 independently of each other. More specifically, the plurality of coaxial cables 23 includes a first coaxial cable 23A and a second coaxial cable 23B. The first coaxial cable 23 </ b> A extends between the detection conductor 21 and the waveform measuring instrument 24 and electrically connects the detection conductor 21 and the waveform measuring instrument 24. On the other hand, the second coaxial cable 23B extends between the correction capacitor 72 and the waveform measuring device 24, and electrically connects the correction conductor 71 and the waveform measuring device 24 via the correction capacitor 72. Yes.

  The waveform measuring device 24 includes an internal circuit 24a that is connected to the first coaxial cable 23A and measures a potential. The waveform measuring device 24 includes an internal circuit 24a that is connected to the second coaxial cable 23B and measures a potential. In the present embodiment, the internal circuit 24a that is connected to the first coaxial cable 23A and measures the potential and the internal circuit 24a that is connected to the second coaxial cable 23B and measures the potential share one internal circuit 24a. Is realized. Note that the internal circuit 24a that is connected to the first coaxial cable 23A and measures the potential and the internal circuit 24a that is connected to the second coaxial cable 23B and measures the potential may be provided separately.

  When the electric charge is induced in the detection conductor 21 by electrostatic induction between the gas discharge P and the detection conductor 21, the waveform measuring device 24 is connected to the internal circuit 24 a based on the electric charge induced in the detection conductor 21. Measure the potential that appears. From a certain viewpoint, the first coaxial cable 23 </ b> A and the internal circuit 24 a of the waveform measuring device 24 form a first circuit (first measurement circuit) 31 electrically connected to the detection conductor 21. The waveform measuring device 24 measures the potential appearing in the first circuit 31 based on the charge induced in the detection conductor 21.

  Similarly, the waveform measuring device 24 corrects based on the charge induced in the correction conductor 71 when the charge is induced in the correction conductor 71 by electrostatic induction between the gas discharge P and the correction conductor 71. The potential appearing in the internal circuit 24a is measured via the capacitor 72 for use. From a certain point of view, the correction capacitor 72, the second coaxial cable 23B, and the internal circuit 24a of the waveform measuring instrument 24 include a second circuit (second measurement circuit) 32 that is electrically connected to the correction conductor 71. Forming. The waveform measuring device 24 measures the potential appearing in the second circuit 32 based on the charge induced in the correction conductor 71. Here, the second circuit 32 includes a correction capacitor 72, for example, and thus has a physical property value different from that of the first circuit 31. For this reason, the potential appearing in the first circuit 31 and the potential appearing in the second circuit 32 are different from each other.

  The calculation unit 46 of the computer 25 includes the potential measured by the first circuit 31 (the potential appearing in the first circuit 31 and measured by the waveform measuring device 24) and the potential measured by the second circuit 32 (second circuit). 32, the potential measured by the waveform measuring device 24), the physical property value of the first circuit 31, and the physical property value of the second circuit 32, the potential of the measurement target site Pt of the gas discharge P, the gas discharge P And the discharge diameter D of the measurement target site Pt of the gas discharge P are calculated. These calculation methods will be described in detail in the following description.

Next, the detection method of the gas discharge P using the detection system 1 of this embodiment is demonstrated.
In the present embodiment, the gas discharge P is based on the potential measured by the first circuit 31, the potential measured by the second circuit 32, the physical property value of the first circuit 31, and the physical property value of the second circuit 32. The potential of the measurement target site Pt is calculated. Specifically, a first equivalent circuit 51 (see FIG. 10) including a capacitance between the gas discharge P and the detection conductor 21 and the first circuit 31 is derived, and the gas discharge P and the correction conductor 71 are derived. The second equivalent circuit 52 (see FIG. 10) including the capacitance between the first circuit 31 and the second circuit 32 is derived, and the potential measured by the first circuit 31 and the potential measured by the second circuit 32 are Based on the physical property value of the first circuit 31, the physical property value of the second circuit 32, the first equivalent circuit 51, and the second equivalent circuit 52, the potential of the gas discharge P is calculated. Hereinafter, this content will be described in detail.

<Derivation of equivalent circuit>
FIG. 10 is a diagram showing an equivalent circuit related to the first circuit 31 and the second circuit 32. (A) in FIG. 10 shows the capacitance between the gas discharge P and the detection conductor 21 (capacitance between the measurement target site Pt of the gas discharge P and the detection conductor 21) and the first circuit. A first equivalent circuit 51 including 31 is shown. 10B shows the capacitance between the gas discharge P and the correction conductor 71 (capacitance between the measurement target site Pt of the gas discharge P and the correction conductor 71) and the second circuit. 32 shows a second equivalent circuit 52. In the figure, v _b is the potential of the measurement target site Pt of the gas discharge P, and is the potential of the detection target. C ₀₁ in the figure is the capacitance between the measurement target site Pt of the gas discharge P and the detection conductor 21, and the static between the measurement target site Pt of the gas discharge P and the correction conductor 71. It is electric capacity. C ₁₂ in the figure is the capacitance of the correction capacitor 72. When the correction electrical element connected to the correction conductor 71 is a coil or a resistor, an inductance or a resistance value is used instead of the capacitance. L _c in the figure is the inductance of each of the first coaxial cable 23A and the second coaxial cable 23B. C _c in the figure is the capacitance of each of the first coaxial cable 23A and the second coaxial cable 23B. _{C DL} in the figure, the capacitance of the internal circuit 24a of the waveform measuring instrument 24. R _DL in the figure is the resistance of the internal circuit 24 a of the waveform measuring instrument 24. V _m1 in the figure is a potential that appears in the first circuit 31 and is measured by the waveform measuring instrument 24. V _m2 in the figure is a potential that appears in the second circuit 32 and is measured by the waveform measuring instrument 24.

Here, the values of the inductance L _c and the capacitance C _c of each of the first coaxial cable 23A and the second coaxial cable 23B can be known by actual measurement. The values of the capacitance C _DL and the resistance R _DL of the internal circuit 24 a of the waveform measuring device 24 can be known from the instruction manual of the waveform measuring device 24 and the like. The potential V _m1 and the potential Vm2 can be known from the measurement result of the waveform measuring instrument 24.

On the other hand, the capacitance C ₀₁ between the measurement target site Pt of the gas discharge P and the detection conductor 21 and the potential v _b of the measurement target site Pt of the gas discharge P are unknown values. In the present embodiment, the static equation between the measurement target site Pt of the gas discharge P and the detection conductor 21 is obtained by simultaneously solving the circuit equation of the first equivalent circuit 51 and the circuit equation of the second equivalent circuit 52. Both the electric capacity C ₀₁ and the potential v _b of the measurement target site Pt of the gas discharge P are calculated.

ここで、ｉは、第１回路３１に流れる電流である。ｔは、時刻である。 <Calculation of circuit equation>
<Calculation of potential vb>
Based on the first equivalent circuit 51, the potential v _b of stbm Pt of gas discharge P can be represented by the circuit equations of the formula (3).

Here, i is a current flowing through the first circuit 31. t is the time.

なお、時刻０ｍｓにおいて、各キャパシタにおける電荷は０Ｃ、電流ｉは０Ａである。 Further, the current i flowing through the first circuit 31 can be expressed by Expression (4).

At time 0 ms, the charge in each capacitor is 0 C and the current i is 0 A.

Then, by substituting Equation (4) into Equation (3), the potential v _b of the measurement target site Pt of the gas discharge P is expressed by the potential v _m1 measured by the waveform measuring device 24 and the capacitance C ₀₁ . Can be represented. Here, in order to prevent complication, the potential at a point b in FIG. 10 represented by substituting Equation (4) into Equation (3) is set to v _r1 . This potential v _r1 is expressed by equation (5).

Similarly, based on the second equivalent circuit 52, the potential v _b of the measurement target portion Pt of the gas discharge P is changed to the potential v _m2 measured by the waveform measuring device 24, the static between the gas discharge P and the correction conductor 71. It can be expressed by the capacitance C ₀₁ and the capacitance C ₁₂ of the correction capacitor 72. That is, the potential v _r2 at the point b in FIG. 10 can be expressed by Expression (6).

Here, C ₀₂ is a combined capacitance of C ₀₁ and C ₁₂ and can be expressed by Expression (7).

By substituting the potentials v _m1 and v _m2 measured by the waveform measuring device 24 at each time t into the equations (5) and (6) and _performing numerical calculations, the potential of the measurement target site Pt of the gas discharge P is calculated. v _b can be calculated.

Note that v _r1 , v _r2 , and v _b all have the same value if C ₀₁ is the same. _However, since _{C 01} is also unknown, in the present embodiment, as shown _{below, v r1} and _{v r2} and calculates the _{C 01} so as to be substantially coincident, _v in _{C 01} calculated _r1 (or v _r2) and the _{v b.}

（ｉｖ）Ｃ_０１にΔＣ_０１を加える。
（ｖ）（ｉｉ）〜（ｉｖ）を繰り返し、評価関数Ｊが最小となるＣ_０１を求める。
これにより、静電容量Ｃ_０１を算出することができる。言い換えると、測定対象の時間帯で平均的にｖ_ｒ１とｖ_ｒ２が最も近い値となる、すなわち評価関数Ｊが最小となるようにＣ_０１を決定する。これにより、測定対象に時間幅がある場合でも、Ｃ_０１を適切に求めることができる。 <Calculation of capacitance C ₀₁ >
The capacitance C ₀₁ can be calculated by the following method.
(I) The capacitance C _{01 is set} to an arbitrary value (value considered to be minute).
(Ii) Substituting the set capacitance C ₀₁ into the equations (5) and (6) to derive v _r1 and v _r2 .
(Iii) Evaluation is performed using v _r1 and v _r2 at time 0 to Tms. As the evaluation function, for example, Expression (8) is adopted.

(Iv) Add ΔC ₀₁ to C ₀₁ .
(V) Repeat (ii) to (iv) to obtain C ₀₁ that minimizes the evaluation function J.
Thereby, the electrostatic capacity C ₀₁ can be calculated. In other words, C ₀₁ is determined so that, on average, v _r1 and v _r2 are closest to each other in the time zone to be measured, that is, the evaluation function J is minimized. Thereby, even when the measurement object has a time width, C ₀₁ can be appropriately obtained.

Next, a method for calculating the discharge diameter D of the measurement target site Pt of the gas discharge P will be described.
FIG. 11 shows a case where two conductors having radii a and b are arranged in parallel at a position of a center distance d (d> a + b). The central axes of both conductors are P and Q, and linear densities λ and −λ are given to the cylindrical conductors P and Q, respectively. As shown in the figure, if P ₁ and Q ₁ are defined on PQ and the following equations (9) and (10) are satisfied, the linear densities λ and −λ passing through P ₁ and Q ₁ The electric field due to the linear charge becomes equal to the electric field in this case.

Here, as shown in FIG. 11, when PP ₁ = d ₁ and QQ ₁ = d ₂ , the equations (9) and (10) can be rewritten as the following equations (11) and (12): .

When the intersections of the line segment PQ and the conductors P and Q are P ₂ and Q ₂ respectively, and using the equations (11) and (12), P ₂ P ₁ , P ₂ Q ₁ , Q ₂ P ₁ , and ₂ Q ₁ is expressed by the following equations (13) to (16), respectively.

The potentials of both cylindrical surfaces are expressed by the following equations (17) and (18) when the potentials at P ₂ and Q ₂ are used.

Therefore, from the equations (17) and (18), the potential difference V _P −V _Q between both cylindrical surfaces is expressed as the following equation (19).

That is, the capacitance C per unit length formed between the two conductors is expressed by the following equation (20).

Here, in this embodiment, two conductors which are the detection conductor 21 and the correction conductor 71 are provided. For this reason, between the gas discharge P and the detection conductor 21, an electrostatic capacitance having a size that is ½ of the value obtained by the equation (20) is formed. Therefore, the radius of the discharge diameter D of the gas discharge P is a, the radius of the detection conductor 21 is b, the length of the detection conductor 21 in the axial direction Z is h, the central axis C of the gas discharge P and the detection conductor 21. When the distance from the center of the d is d, the following equation (21) is established.

Therefore, the capacitance C ₀₁ calculated based on the equation (8), the radius b of the detection conductor 21, the length h in the axial direction Z of the detection conductor 21, and the gas discharge P By substituting the distance d between the central axis C and the center of the detection conductor 21 and the dielectric constant ε between the gas discharge P and the detection conductor 21, the radius a of the discharge diameter D of the gas discharge P can be obtained. Can be calculated. Thereby, the discharge diameter D of the gas discharge P is computable.

  FIG. 12 is a flowchart showing an example of the processing flow of the present embodiment, and shows an example of the processing flow when the processing is executed by the computer 25, for example. Steps S11, S12, and S14 are the same as those in the first embodiment, and a description thereof is omitted.

In the present embodiment, as preparation, information on the derived first equivalent circuit 51 and second equivalent circuit 52 (for example, a calculation formula for solving the circuit equations of the first equivalent circuit 51 and the second equivalent circuit 52) is provided. And stored in the storage unit 42 of the computer 25. Further, the values of the inductance L _c and the capacitance C _c of the coaxial cable 23A and the coaxial cable 23B are stored in the storage unit 42 of the computer 25 as the physical property values of the coaxial cable 23 (physical property values of the circuits 31 and 32). . The values of the capacitance C _DL and the resistance R _DL of the internal circuit 24 a of the waveform measuring device 24 are the physical property values of the internal circuit 24 a of the waveform measuring device 24 (the physical property values of the circuits 31 and 32). Is remembered. Further, the value of the capacitance C ₁₂ of the correction capacitor 72 is stored in the storage unit 42 of the computer 25 as a physical property value of the circuit 32. Note that some or all of these information and numerical values may be received in the middle of processing instead of being stored in advance.

As shown in FIG. 12, in the present embodiment, calculation unit 46, based on the step S11, S12, and information obtained by S14, and calculates the electric potential _{v b} of stbm Pt gas discharge P (step S15 ). Specifically, the circuit equation of the first equivalent circuit 51 is based on the potential v _m1 and the potential Vm ₂ measured by the waveform measuring instrument 24, the physical property value of the first circuit 31, and the physical property value of the second circuit 32. When by the circuit equations of the second equalizer circuit 52 by simultaneous solved by numerical calculation, to calculate the potential v _b of stbm Pt of gas discharge P.

Further, the calculation unit 46 of the present embodiment calculates the capacitance C ₀₁ between the gas discharge P and the detection conductor 21 based on the information obtained in steps S11, S12, and S14 (step S21). . Specifically, the calculation unit 46 solves the circuit equation of the first equivalent circuit 51 and the circuit equation of the second equivalent circuit 52 by numerical calculation and solves the potential v of the measurement target site Pt of the gas discharge P. _A capacitance C ₀₁ is calculated together with _b . For example, in the present embodiment, the capacitance C ₀₁ is calculated by performing a calculation based on the above equation (8).

Next, the calculation unit 46 calculates the discharge diameter D of the measurement target site Pt of the gas discharge P based on the calculated capacitance C ₀₁ (step S22). For example, in the present embodiment, the discharge diameter D of the measurement target site Pt of the gas discharge P is calculated by performing the calculation based on the above formula (21). Then, the calculation unit 46 sends the calculation result to the information output unit 47 (step S16).

  According to such a method, the state of the gas discharge P can be detected with higher accuracy. That is, in the present embodiment, the detection conductor 21 and the correction conductor 71 are provided so as to correspond to substantially the same part of the gas discharge P. Based on the potential measured by the first circuit 31, the potential measured by the second circuit 32, the physical property value of the first circuit 31, and the physical property value of the second circuit 32, the potential of the gas discharge P is Calculated. That is, based on the two circuits 31 and 32, the potential of the measurement target site Pt of the gas discharge P can be calculated with higher accuracy.

  In the present embodiment, the first equivalent circuit 51 including the capacitance between the gas discharge P and the detection conductor 21 and the first circuit 31 is derived, and the static between the gas discharge P and the correction conductor 71 is derived. The second equivalent circuit 52 including the capacitance and the second circuit 32 is derived, the potential measured by the first circuit 31, the potential measured by the second circuit 32, the physical property value of the first circuit 31, and Based on the physical property value of the second circuit 32, the first equivalent circuit 51, and the second equivalent circuit 52, the potential of the gas discharge P is calculated. According to such a method, the potential of the gas discharge P can be calculated with higher accuracy by calculating the potential of the gas discharge P based on the two equivalent circuits 51 and 52.

In the present embodiment, the detection conductor 21 and the correction conductor 71 are disposed at substantially the same distance from the gas discharge P. The capacitance between the gas discharge P and the detection conductor 21 and the capacitance between the gas discharge P and the correction conductor 71 are considered to be the same. Thereby, the potential of the gas discharge P can be calculated without assuming the capacitance C ₀₁ between the gas discharge P and the detection conductor 21. For this reason, the potential of the gas discharge P can be calculated with higher accuracy.

  In the present embodiment, the potential measured by the first circuit 31, the potential measured by the second circuit 32, the physical property value of the first circuit 31, the physical property value of the second circuit 32, and the first circuit 31 Based on the equivalent circuit and the equivalent circuit of the second circuit 32, the capacitance between the gas discharge P and the detection conductor 21 is calculated. Then, the discharge diameter D of the gas discharge P is calculated based on the calculated capacitance. Thereby, in addition to the potential of the gas discharge P, the state of the discharge diameter D of the gas discharge P can also be known. For example, according to the present embodiment, it is possible to detect in a non-contact manner a temporal variation of the “potential of the measurement target site Pt” and the “discharge diameter D of the measurement target site Pt” of the gas discharge P.

  For example, in the case of a gas circuit breaker or a vacuum circuit breaker, if the discharge diameter D of the gas discharge P near the zero point of the current can be known, the gas discharge P can be cut off at a position where it is easier to cut off. Thereby, the interruption | blocking performance of a gas circuit breaker or a vacuum circuit breaker can further be improved.

Next, some modifications of the present embodiment will be described.
FIG. 13 is a cross-sectional view showing a detection system 1 of a first modification.
As shown in FIG. 13, in this modification, the detection conductor 21 and the correction conductor 71 are formed in a flat shape along the circumferential direction θ of the gas discharge P. According to such a configuration, charges are more easily induced to the detection conductor 21 and the correction conductor 71 more stably. For this reason, the potential of the gas discharge P and the like can be calculated with higher accuracy.

FIG. 14 is a cross-sectional view showing a detection system 1 of a second modification.
As shown in FIG. 14, in this modification, a plurality of detection conductors 21 and a plurality of correction conductors 71 are provided. The plurality of detection conductors 21 are arranged corresponding to the same measurement target site Pt of the gas discharge P as positions in the axial direction of the gas discharge P, and are separated from each other in the circumferential direction θ. The plurality of detection conductors 21 are electrically connected to the waveform measuring instrument 24 independently of each other by a plurality of first coaxial cables 23A. Similarly, the plurality of correction conductors 71 are arranged corresponding to the same measurement target site Pt of the gas discharge P as the positions in the axial direction of the gas discharge P, and are arranged separately in the circumferential direction θ. . A correction capacitor 72 is electrically connected to each of the plurality of correction conductors 71. The plurality of correction conductors 71 are electrically connected to the waveform measuring instrument 24 independently of each other by a plurality of second coaxial cables 23B. According to such a structure, the influence by the shift | offset | difference of the radial direction R of the gas discharge P can be made small by utilizing the measurement result using the several conductor 21 for a detection, and the several conductor 71 for correction | amendment. Thereby, the potential of the gas discharge P and the discharge diameter D can be calculated with higher accuracy.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIG. This embodiment is different from the sixth embodiment in that a plurality of detection conductors 21, a plurality of correction conductors 71, a plurality of ground conductors 22 and the like are provided. The configurations other than those described below are the same as those in the sixth embodiment.

  FIG. 15 is a diagram illustrating a detection system 1 according to the seventh embodiment. (A) in FIG. 15 is a sectional view showing the detection system 1. (B) in FIG. 15 is a cross-sectional view taken along line F15b-F15b of the detection system 1 shown in (a) in FIG.

As shown in FIG. 15, the detection system 1 of the present embodiment includes a plurality of detection conductors 21, a plurality of correction conductors 71, and a plurality of ground conductors 22, as in the third embodiment.
The plurality of detection conductors 21 are separately arranged at different positions in the axial direction Z of the gas discharge P. The plurality of detection conductors 21 are arranged at positions corresponding to the plurality of measurement target portions Pt of the gas discharge P, respectively. The plurality of detection conductors 21 are connected to the waveform measuring device 24 by a plurality of first coaxial cables 23A independently of each other.

  The plurality of correction conductors 71 are separately arranged at different positions in the axial direction Z of the gas discharge P. The plurality of correction conductors 71 are respectively arranged at positions corresponding to the detection conductors 21. The plurality of correction conductors 71 are connected to the waveform measuring instrument 24 by a plurality of second coaxial cables 23B independently of each other. A correction capacitor 72 is provided between each correction conductor 71 and each second coaxial cable 23B. The number of the detection conductors 21 and the correction conductors 71 is not limited to three, and may be two or four or more.

  According to such a configuration, by providing the plurality of detection conductors 21, the potentials of the plurality of measurement target portions Pt of the gas discharge P can be detected. Thereby, the potential distribution in the axial direction Z of the gas discharge P and the spatial distribution of the discharge diameter D in the axial direction Z of the gas discharge P can be obtained. For example, according to the present embodiment, it is possible to detect in a non-contact manner temporal variations of “the potential distribution in the axial direction Z of the gas discharge P” and “the spatial distribution of the discharge diameter D in the axial direction Z of the gas discharge P”. .

(Eighth embodiment)
Next, an eighth embodiment will be described with reference to FIG. This embodiment is different from the seventh embodiment in that the third ground conductor 22C is not provided. The configurations other than those described below are the same as those in the seventh embodiment.

  FIG. 16 is a diagram illustrating a detection system 1 according to the eighth embodiment. (A) in FIG. 16 is a cross-sectional view showing the detection system 1. (B) in FIG. 16 is a cross-sectional view taken along the line F16b-F16b of the detection system 1 shown in (a) in FIG.

  As shown in FIG. 16, the detection system 1 of the present embodiment has a first ground conductor 22A and a second ground conductor 22B, as in the fifth embodiment. On the other hand, the detection system 1 does not have the third ground conductor 22C. That is, in the present embodiment, the ground conductor 22 is provided only in the end region where the plurality of detection conductors 21 are not adjacent to each other.

  According to such a configuration, the plurality of detection conductors 21 can be arranged at narrow intervals. Therefore, the number of detection conductors 21 and correction conductors 71 provided for the gas discharge P can be increased. Thereby, the potential distribution in the axial direction Z of the gas discharge P and the spatial distribution of the discharge diameter D in the axial direction Z can be obtained with higher accuracy.

(Ninth embodiment)
Next, a ninth embodiment will be described with reference to FIG. This embodiment is different from the sixth embodiment in that at least three conductors are provided. The configurations other than those described below are the same as those in the sixth embodiment.

  The detection system 1 of the present embodiment is a system that calculates the position of the gas discharge P in the radial direction R (the amount of deviation with respect to the central axis C) in addition to the potential of the gas discharge P and the discharge diameter D.

FIG. 17 is a cross-sectional view showing the detection system 1 of the ninth embodiment.
As shown in FIG. 17, the detection system 1 of the present embodiment includes at least three conductors (detection conductor 21, first correction conductor 71A, and second correction conductor 71B), and at least two correction capacitors, for example. (First correction capacitor 72A and second correction capacitor 72B), at least three coaxial cables 23 (first coaxial cable 23A, second coaxial cable 23B, and third coaxial cable 23C) and waveform measuring instrument 24. And a computer 25.

  At least three conductors (detection conductor 21, first correction conductor 71A, and second correction conductor 71B) have, for example, substantially the same shape as each other, and substantially the same part of gas discharge P (same measurement target part Pt). It is arranged corresponding to. In other words, the at least three conductors are arranged at substantially the same position as the position in the axial direction Z of the gas discharge P. The detection conductor 21 is an example of a “first conductor”. The first correction conductor 71A is an example of a “second conductor”. The second correction conductor 71B is an example of a “third conductor”.

  The first correction capacitor 72A is an example of a “first electric element (correction electric element)”. The first correction capacitor 72A is electrically connected to the first correction conductor 71A. For example, the first correction capacitor 72A is electrically connected in series to the first correction conductor 71A. The capacitance of the first correction capacitor 72A can be known from catalog values or actual measurements. On the other hand, the second correction capacitor 72B is an example of a “second electric element (correction electric element)”. The second correction capacitor 72B is electrically connected to the second correction conductor 71B. For example, the second correction capacitor 72B is electrically connected in series to the second correction conductor 71B. The capacitance of the second correction capacitor 72B can be known from catalog values or actual measurements. For example, the first correction conductor 71A and the second correction conductor 71B have different physical property values. The electrical element (correction electrical element) electrically connected to the first correction conductor 71A and the second correction conductor 71B is not limited to the correction capacitors 72A and 72B, and may be a coil or a resistor.

  At least three coaxial cables 23 (first coaxial cable 23A, second coaxial cable 23B, and third coaxial cable 23C) electrically connect the at least three conductors to waveform measuring instrument 24 independently of each other. Yes. For example, the first coaxial cable 23 </ b> A extends between the detection conductor 21 and the waveform measurement device 24 and electrically connects the detection conductor 21 and the waveform measurement device 24. The second coaxial cable 23 </ b> B extends between the first correction capacitor 72 </ b> A and the waveform measuring device 24, and electrically connects the first correction capacitor 72 </ b> A and the waveform measuring device 24. The third coaxial cable 23 </ b> C extends between the second correction capacitor 72 </ b> B and the waveform measurement device 24, and electrically connects the second correction capacitor 72 </ b> B and the waveform measurement device 24.

  The first coaxial cable 23A and the internal circuit 24a of the waveform measuring device 24 form a first circuit (first measurement circuit) 31 that is electrically connected to the detection conductor 21. The waveform measuring device 24 measures the potential appearing in the first circuit 31 based on the charge induced in the detection conductor 21. The second coaxial cable 23B and the internal circuit 24a of the waveform measuring instrument 24 form a second circuit (second measurement circuit) 32 that is electrically connected to the first correction conductor 71A. The waveform measuring device 24 measures the potential appearing in the second circuit 32 based on the charge induced in the first correction conductor 71A. The third coaxial cable 23C and the internal circuit 24a of the waveform measuring device 24 form a third circuit (third measurement circuit) 33 that is electrically connected to the second correction conductor 71B. The waveform measuring device 24 measures the potential appearing in the third circuit 33 based on the charge induced in the second correction conductor 71B. Here, the second circuit 32 includes a correction capacitor 72A, for example, and thus has a physical property value different from that of the first circuit 31. The third circuit 33 includes a correction capacitor 72B, for example, so that the physical property values are different from those of the first circuit 31 and the second circuit 32. For this reason, the potential appearing in the first circuit 31, the potential appearing in the second circuit 32, and the potential appearing in the third circuit 33 are different from each other.

  In the present embodiment, the calculation unit 46 of the computer 25 measures the potential measured by the first circuit 31 (the potential appearing in the first circuit 31 and measured by the waveform measuring device 24) and the second circuit 32. A potential (a potential appearing in the second circuit 32 and measured by the waveform measuring instrument 24), a potential measured in the third circuit 33 (a potential appearing in the second circuit 33 and measured by the waveform measuring instrument 24), and Based on the physical property value of the first circuit 31, the physical property value of the second circuit 32, and the physical property value of the third circuit 33, the potential of the measurement target site Pt of the gas discharge P, the gas discharge P, and the detection conductor 21 The electrostatic capacity between them, the discharge diameter D of the measurement target site Pt of the gas discharge P, and the radial position of the gas discharge P are calculated. That is, as in the sixth embodiment, the calculation unit 46 of the computer 25 generates an equivalent circuit (for example, three equivalent circuits) including the capacitance between each of the three conductors and the gas discharge P. Based on these equivalent circuits, the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21, the discharge diameter D of the measurement target site Pt of the gas discharge P, And the position (deviation amount) in the radial direction of the gas discharge P is calculated. That is, three unknowns (the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21 (or the discharge diameter D), and the radial position of the gas discharge P). On the other hand, the physical quantity can be obtained by solving three equivalent circuits. Note that the method for calculating the physical quantity based on the equivalent circuit is the same as that in the sixth embodiment, and thus detailed description thereof is omitted.

  According to such a configuration, by providing at least three conductors, the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21, and the measurement of the gas discharge P are measured. The discharge diameter D of the target site Pt and the radial position of the gas discharge P can be calculated simultaneously. When the potentials measured by at least three conductors arranged corresponding to substantially the same part of the gas discharge P are different from each other, one or both of the first correction capacitor 72A and the second correction capacitor 72B are required. Instead, the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21, the discharge diameter D of the measurement target site Pt of the gas discharge P, and the diameter of the gas discharge P In some cases, the position of the direction can be calculated. In this case, at least three detection conductors 21 may be provided in place of the at least three conductors (detection conductor 21, first correction conductor 71A, and second correction conductor 71B).

(Modification)
Next, a modification of the ninth embodiment will be described.
In this modification, a potential pattern (or potential difference pattern) appearing in at least three conductors arranged corresponding to substantially the same part of the gas discharge P is obtained by a prior experiment or simulation and stored in the storage unit 42. ing. For example, by assuming the discharge diameter D of the measurement target site Pt of the gas discharge P and the radial position of the gas discharge P, the capacitance between the gas discharge P and each of the at least three conductors, The capacitance between the conductors of the at least three conductors can be obtained. For this reason, for example, a preliminary experiment or simulation is performed by assuming (assuming) several tens of patterns in advance of the discharge diameter D of the measurement target site Pt of the gas discharge P and the radial position of the gas discharge P. Thus, potentials appearing in each of the at least three conductors can be derived and stored in the storage unit 42 as simulation results.

  Then, the calculation unit 46 of the computer 25 derives the radial position of the gas discharge P by comparing the actually measured potential with the experimental result or simulation result stored in the storage unit 42. Can do. When the radial position of the gas discharge P is derived by such a method, one or both of the first correction capacitor 72A and the second correction capacitor 72B in the ninth embodiment may be omitted. In this case, at least three detection conductors 21 may be provided in place of the at least three conductors (detection conductor 21, first correction conductor 71A, and second correction conductor 71B).

(Tenth embodiment)
Next, a tenth embodiment will be described with reference to FIGS. 18 and 19. This embodiment is different from the seventh embodiment in that a plurality of measurement coils 81 are provided. The configurations other than those described below are the same as those in the seventh embodiment.

  FIG. 18 is a diagram illustrating the detection system 1 according to the tenth embodiment. (A) in FIG. 18 is a cross-sectional view showing the detection system 1. (B) in FIG. 18 is a cross-sectional view taken along the line F18b-F18b of the detection system 1 shown in (a) in FIG.

  The detection system 1 of the present embodiment is a system that calculates the position (deviation amount) of the gas discharge P in the radial direction R in addition to the potential of the gas discharge P and the discharge diameter D.

  The detection system 1 of the present embodiment includes a plurality of measurement coils 81 in addition to the configuration of the seventh embodiment. The measuring coil 81 is an example of a “coil”. The plurality of measurement coils 81 are divided into a plurality of coil sets S. Each coil set S is disposed at a position corresponding to the measurement target site Pt of the gas discharge P in the axial direction Z of the gas discharge P. Each coil set S includes a plurality of (for example, two) measuring coils 81. In other words, a plurality of (for example, two) measurement coils 81 included in each coil set S are arranged corresponding to substantially the same position of the gas discharge P in the axial direction Z of the gas discharge P.

  Each measurement coil 81 is arranged so that the magnetic field formed by the current of the gas discharge P passes through the ring of the measurement coil 81. Each measuring coil 81 is electrically connected to the waveform measuring instrument 24 by the coaxial cable 23. The plurality of measurement coils 81 included in each coil set S are separately provided in the circumferential direction θ of the gas discharge P. For example, the plurality of measurement coils 81 are arranged separately on both sides of the central axis C of the gas discharge P. The plurality of measurement coils 81 included in each coil set S are arranged at substantially equal distances from the central axis C of the gas discharge P. The plurality of measurement coils 81 included in each coil set S are arranged at positions that are approximately 90 ° different from the detection conductor 21 and the correction conductor 71 in the circumferential direction θ of the gas discharge P, for example. The arrangement position of the measurement coil 81 is not limited to the above example.

Next, a method for calculating the position in the radial direction R of the gas discharge P using the measurement coil 81 will be described.
Since a current flows through the gas discharge P, a magnetic field is formed around the gas discharge P according to the rate of change di / dt of the current. The rate of change of the magnetic field is set by, for example, arranging the measuring coil 81 perpendicularly to the magnetic field lines of the magnetic field formed by the gas discharge P, that is, so that the magnetic field lines pass through the ring of the measuring coil 81. Is induced in each measuring coil 81. The current value of the current induced in each measurement coil 81 is measured by the waveform measuring device 24.

  When the gas discharge P is on the central axis C, the current values of the currents induced in the two measurement coils 81 included in each coil set S are substantially the same value. On the other hand, when the gas discharge P deviates from the central axis C in the radial direction R, the current values of the currents induced in the two measurement coils 81 included in each coil set S are different from each other. Further, the difference between the current values of the currents induced in the two measuring coils 81 included in the same coil set S increases according to the amount of deviation of the gas discharge P from the central axis C. For this reason, the position (deviation amount) in the radial direction R of the gas discharge P is calculated by calculating backward based on the difference between the current values of the currents induced in the two measuring coils 81 included in the same coil set S. can do. The relationship between the difference between the current values of the currents induced in the two measuring coils 81 included in the same coil set S and the position (deviation amount) in the radial direction R of the gas discharge P is, for example, an electric device. It can be obtained by calculation using a model simulating 10 or by a prior experiment.

  FIG. 19 is a flowchart showing an example of the processing flow of the present embodiment, and shows an example of the processing flow when processing is executed by the computer 25, for example. Note that steps S11, S12, S14, S15, S21, and S22 are the same as those in the sixth embodiment, and a description thereof will be omitted.

  In this embodiment, as advance preparation, the difference between the current values of the currents induced in the two measurement coils 81 included in the same coil set S obtained in advance by experiments and simulations, and the diameter of the gas discharge P Information indicating the relationship with the position (shift amount) in the direction R is stored in the storage unit 42 of the computer 25.

  As shown in FIG. 19, the calculation unit 46 of the present embodiment calculates the difference between the current values of the currents induced in the two measurement coils 81 included in the same coil set S obtained in advance and the gas discharge. Based on the information indicating the relationship between the position of P in the radial direction R and the difference between the current values of the currents induced in the two measuring coils 81 included in the measurement result of the waveform measuring device 24 acquired in step S11. Then, the position in the radial direction R of the gas discharge P is calculated (step S31). Then, the calculation unit 46 sends the calculation result to the information output unit 47 (step S16).

  According to such a method, the current value flowing through each of the plurality of measurement coils 81 arranged corresponding to substantially the same portion of the gas discharge P by the magnetic field formed by the gas discharge P is measured, and the measured current value is measured. Based on the above, the position in the radial direction R of the gas discharge P is calculated. For example, according to the present embodiment, “the potential distribution in the axial direction Z of the gas discharge P”, “the spatial distribution of the discharge diameter D in the axial direction Z of the gas discharge P”, and “the position in the radial direction R of the gas discharge P” ”Can be detected without contact. The calculation of the “position of the gas discharge P in the radial direction R” includes calculation of “the potential distribution of the gas discharge P in the axial direction Z” and “the spatial distribution of the discharge diameter D of the gas discharge P in the axial direction Z”. May be implemented independently.

  In the first to ninth embodiments, as the detection conductor 21 and the correction conductor 71 (correction conductors 71A and 71B), annular or rod-shaped electrodes are provided. Instead, the detection conductor 21 and the correction conductor 71 in the first to ninth embodiments may be replaced with a measurement coil 81. In this case, a circuit (for example, the circuit 31, the circuit 32, and the circuit 33) is electrically connected to each measurement coil 81, and appears in the circuit by electrostatic induction between the gas discharge P and each measurement coil 81. Each potential is measured. One of the two measurement coils 81 included in each coil set S is an example of a “first coil”. The other of the two measurement coils 81 included in each coil set S is an example of a “second coil”. And the calculation part 46 of the computer 25 is based on the electric potential which appeared in each circuit by the electrostatic induction between the gas discharge P and each measuring coil 81, and was measured, and the physical property value of each circuit from 1st to 1st 9, the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21, and the discharge diameter D of the measurement target site Pt of the gas discharge P are calculated. May be. That is, the detection system 1 uses two or more measurement coils 81 to measure the potential of the measurement target site Pt of the gas discharge P, the capacitance between the gas discharge P and the detection conductor 21, and the gas discharge P. The discharge diameter D of the measurement target site Pt and the position (deviation amount) in the radial direction R of the gas discharge P may be calculated.

  As described above, part or all of the detection method of the gas discharge P described in the first to tenth embodiments and the modifications thereof is a program (computer program, software component) stored in the storage unit 42 of the computer 25. ) May be implemented by the processor (hardware processor) 41. In other words, some or all of the functional units (for example, the information acquisition unit 45, the calculation unit 46, and the information output unit 47) of the computer 25 described above are realized by, for example, the program being executed by the processor 41. This is a software function unit. Alternatively, part or all of the detection method of the gas discharge P (or each functional unit of the computer 25) described above is LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array). It may be realized by hardware such as, or may be realized by a combination of a software function unit and hardware. The program may be stored in a computer-readable storage medium (for example, a non-transitory storage medium). And the said function may be implement | achieved when a computer reads and runs the program memorize | stored in the storage medium. Here, the “computer” includes hardware such as an operating system and peripheral devices. The “computer-readable storage medium” refers to a portable medium or a storage device. The portable medium is a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, a USB memory, or the like. The storage device is an HDD, a semiconductor memory, or the like. The above program may be executable by the computer 25 via a network.

  In addition, part or all of the functions of the waveform measuring device 24 (measurement unit) that measures the potential may be realized by the computer 25. That is, part or all of the functions of the waveform measuring instrument 24 (measurement unit) for measuring the potential may be realized by the software function unit as described above, or may be realized by hardware. It may be realized by a combination with hardware.

  The configuration of the electric device 10 to which the detection system 1 of the embodiment and the modification described above can be applied is not limited to the above example. The electrical device 10 corresponds to various electrical devices such as a power transmission / transformation facility such as a gas circuit breaker or a vacuum circuit breaker, a fluorescent lamp, an ozone generator, an in-vehicle relay, and a car fuse as appropriate.

  According to at least one embodiment described above, a potential appearing in a circuit electrically connected to the conductor is measured by electrostatic induction between the gas discharge and the conductor, and the measured potential and the circuit Based on the physical property values, the gas discharge potential is calculated. According to such a method, the state of gas discharge can be detected.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... State detection system, 21 ... Detection conductor (conductor, 1st conductor), 22 ... Grounding conductor, 23 ... Coaxial cable, 24 ... Waveform measuring device, 25 ... Computer, 31 ... Circuit (1st circuit), 32 ... Second circuit 46... Calculation unit 51... Equivalent circuit (first equivalent circuit) 52. Second equivalent circuit 71 71 Correction conductor (second conductor) 71 A First correction conductor (second conductor) 71B ... second correction conductor (third conductor), 72 ... correction capacitor, 81 ... measurement coil (coil), P ... gas discharge, Pt ... measurement site, D ... discharge diameter, Z ... axial direction, R: radial direction.

Claims (18)

Measuring the potential appearing in a circuit electrically connected to the conductor by electrostatic induction between the gas discharge and the conductor;
Based on the measured potential and the physical property value of the circuit, the potential of the gas discharge is calculated.
Gas discharge state detection method. Calculating the potential of the gas discharge
Deriving an equivalent circuit including the capacitance and the circuit between the gas discharge and the conductor,
Based on the measured potential, the physical property value of the circuit, and the equivalent circuit, the potential of the gas discharge is calculated.
Including that,
The gas discharge state detection method according to claim 1. Calculating the potential of the gas discharge
Assuming a capacitance between the gas discharge and the conductor,
Calculating the potential of the gas discharge based on the measured potential, the physical property value of the circuit, the equivalent circuit, and the assumed capacitance;
Including that,
The gas discharge state detection method according to claim 2. The conductor is formed in an annular shape surrounding the gas discharge,
The gas discharge state detection method according to any one of claims 1 to 3. The conductor includes a first conductor and a second conductor arranged corresponding to substantially the same part of the gas discharge,
The circuit includes a first circuit electrically connected to the first conductor, and a second circuit having a physical property value different from that of the first circuit and electrically connected to the second conductor,
Calculating the potential of the gas discharge
The potential of the gas discharge is calculated based on the potential measured in the first circuit, the potential measured in the second circuit, the physical property value of the first circuit, and the physical property value of the second circuit. ,
Including that,
The gas discharge state detection method according to claim 1. Calculating the potential of the gas discharge
Deriving a first equivalent circuit including a capacitance between the gas discharge and the first conductor and the first circuit;
Deriving a second equivalent circuit including a capacitance between the gas discharge and the second conductor and the second circuit;
The potential measured in the first circuit, the potential measured in the second circuit, the physical property value of the first circuit, the physical property value of the second circuit, the first equivalent circuit, and the second Based on the equivalent circuit, calculate the potential of the gas discharge,
Including that,
The gas discharge state detection method according to claim 5. The first conductor and the second conductor are arranged at an approximately equal distance with respect to the gas discharge,
Calculating the potential of the gas discharge
The capacitance between the gas discharge and the first conductor is considered to be the same as the capacitance between the gas discharge and the second conductor;
Including that,
The gas discharge state detection method according to claim 6. The potential measured in the first circuit, the potential measured in the second circuit, the physical property value of the first circuit, the physical property value of the second circuit, the first equivalent circuit, and the second Based on the equivalent circuit, the capacitance between the gas discharge and the first conductor is calculated,
Based on the calculated capacitance, a discharge diameter of the gas discharge is calculated.
The gas discharge state detection method according to claim 7. The conductor includes a third conductor disposed corresponding to substantially the same part of the gas discharge with respect to the first conductor and the second conductor;
The circuit includes a third circuit electrically connected to the third conductor;
Based on the potential measured in the first circuit, the potential measured in the second circuit, and the potential measured in the third circuit, the potential of the gas discharge, the discharge diameter of the gas discharge, Calculating the radial position of the gas discharge;
The gas discharge state detection method according to any one of claims 5 to 8. The conductor includes a first conductor, a second conductor, and a third conductor arranged corresponding to substantially the same part of the gas discharge,
The circuit includes a first circuit electrically connected to the first conductor, a second circuit electrically connected to the second conductor, and a third circuit electrically connected to the third conductor. Including
Deriving the radial position of the gas discharge based on the potential measured in the first circuit, the potential measured in the second circuit, and the potential measured in the third circuit;
The gas discharge state detection method according to any one of claims 1 to 8. The potential is measured with the grounded ground conductor adjacent to the conductor in the axial direction of the gas discharge.
The gas discharge state detection method according to any one of claims 1 to 10. The conductor includes a plurality of conductors arranged separately in the axial direction of the gas discharge,
The ground conductor is adjacent to the conductor farthest from the central portion of the gas discharge among the plurality of conductors from the opposite side of the central portion of the gas discharge in the axial direction of the gas discharge.
The gas discharge state detection method according to claim 11. Measure the current value flowing in each of a plurality of coils arranged corresponding to substantially the same part of the gas discharge by the magnetic field formed by the gas discharge,
Based on the measured current value, the radial position of the gas discharge is calculated.
The gas discharge state detection method according to any one of claims 1 to 12. Measure the current value flowing in each of a plurality of coils arranged corresponding to substantially the same part of the gas discharge by the magnetic field formed by the gas discharge,
Based on the measured current value, the radial position of the gas discharge is calculated.
Gas discharge state detection method. Measuring a potential appearing in a circuit electrically connected to the coil by electrostatic induction between the gas discharge and at least one coil included in the plurality of coils;
Based on the measured potential and the physical property value of the circuit, the potential of the gas discharge is calculated.
The gas discharge state detection method according to claim 14. The plurality of coils include a first coil and a second coil arranged corresponding to substantially the same part of the gas discharge,
The circuit includes a first circuit electrically connected to the first coil, and a second circuit having a physical property value different from that of the first circuit and electrically connected to the second coil,
The discharge diameter of the gas discharge is calculated based on the potential measured in the first circuit, the potential measured in the second circuit, the physical property value of the first circuit, and the physical property value of the second circuit. To
The gas discharge state detection method according to claim 15. On the computer,
Based on the potential appearing in the circuit electrically connected to the conductor by electrostatic induction between the gas discharge and the conductor, and the physical property value of the circuit, the potential of the gas discharge is calculated.
Gas discharge status detection program. A calculation unit for calculating a potential of the gas discharge based on a potential appearing in a circuit electrically connected to the conductor by electrostatic induction between the gas discharge and the conductor, and a physical property value of the circuit;
A gas discharge state detection system.

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