JP2018040775A - Leakage current measurement method for transmission line arrester and measurement apparatus - Google Patents

Abstract

There is provided a leakage current measuring method capable of easily measuring a leakage current of a lightning arrester. According to one embodiment, a leakage current measuring method includes electrically connecting a first discharge electrode and a second discharge electrode by a connecting device and electrically connecting them in series. Measuring leakage current of the lightning arrester from electricity flowing in the second discharge electrode, the connection device, the first discharge electrode, and the lightning arrester. The connection device is provided between the first discharge electrode and the second discharge electrode, and is electrically connected in series. The second discharge electrode, the connection device, and the first discharge electrode. And an element capable of interrupting the application of the voltage of the power transmission line to the first support part via the lightning arrester. [Selection] Figure 1

Description

  Embodiments described herein relate generally to a leakage current measurement method and a measurement apparatus for a lightning arrester for power transmission.

  The transmission line is supported by the transmission tower via insulators. For example, in order to suppress the occurrence of a ground fault from the insulator due to a surge voltage caused by lightning, a gap (discharge electrode) called an arc horn is provided in parallel with the insulator. When the surge voltage is generated, the arc horn is discharged, so that the insulator and the connected device are prevented from being damaged by the surge voltage.

  A ground fault may occur due to the discharge of the arc horn. In order to suppress the ground fault, for example, an arc horn type lightning arrester is provided. In the lightning arrester, for example, a lightning arrester having a gap is provided in parallel with the arc horn.

  The lightning arrester is inspected by visual inspection, for example. For example, when an internal element of the lightning arrester fails, the insulator covering the internal element may be damaged. The lightning arrester is maintained and inspected by checking for abnormalities occurring in the appearance.

Japanese Patent Laid-Open No. 2-67969

  A lightning arrester may have a failure without appearance abnormality and deterioration of electrical characteristics. On the other hand, by measuring the leakage current of the lightning arrester, failure of the lightning arrester and deterioration of electrical characteristics can be detected. However, since a relatively large voltage is used for measuring the leakage current, it may be difficult to prepare a power source used for measuring the leakage current.

  A leakage current measurement method according to an embodiment includes a first support part supported by a grounded object, a second support part that supports a power transmission line, the first support part, and the second support. A lightning arrester connected to the first support part, a first discharge electrode connected to the lightning arrester, and a second discharge electrode connected to the second support part, , A leakage current measuring method for a lightning arrester for power transmission. In the leakage current measuring method, the first discharge electrode and the second discharge electrode are electrically connected by a connection device, the second discharge electrode electrically connected in series, and the connection Measuring leakage current of the lightning arrester from electricity flowing through the device, the first discharge electrode, and the lightning arrester. The connection device is provided between the first discharge electrode and the second discharge electrode, and is electrically connected in series. The second discharge electrode, the connection device, and the first discharge electrode. And an element capable of cutting off the application of the voltage of the power transmission line to the first support portion via the lightning arrester.

FIG. 1 is a side view showing a lightning arrester for power transmission according to the first embodiment. FIG. 2 is a side view in which a part of the measuring apparatus according to the first embodiment is cut away. FIG. 3 is a circuit diagram of the lightning arrester for power transmission and the measurement device according to the first embodiment. FIG. 4 is a block diagram functionally illustrating the configuration of the measurement apparatus according to the first embodiment. FIG. 5 is a flowchart illustrating an example of a method for measuring leakage current of the lightning arrester for power transmission according to the first embodiment. FIG. 6 is a side view showing the measuring apparatus attached to the first gap of the first embodiment. FIG. 7 is a side view showing a lightning arrester for power transmission according to the second embodiment. FIG. 8 is a side view schematically showing a part of the lightning arrester for power transmission according to the second embodiment. FIG. 9 is a circuit diagram of the lightning arrester for power transmission and the measurement device of the second embodiment.

  The first embodiment will be described below with reference to FIGS. 1 to 6. In the present specification, basically, a vertically upward direction is defined as an upward direction and a vertically downward direction is defined as a downward direction. In addition, a plurality of expressions may be written together for the constituent elements according to the embodiment and the description of the elements. It is not precluded that other expressions not described in the component and description are made. Furthermore, it is not prevented that other expressions are given for the components and descriptions in which a plurality of expressions are not described.

  FIG. 1 is a side view showing a lightning arrester 11 for power transmission according to the first embodiment. As shown in FIG. 1, the lightning arrester 11 for power transmission is supported by a steel tower 12 and supports a power transmission line 13. The steel tower 12 is an example of a grounded object.

  The steel tower 12 is constructed and grounded at various places such as mountainous areas. The steel tower 12 has a support arm 15. The power transmission line 13 constitutes a power transmission network that is a part of the power system. In this specification, the voltage applied to the power transmission line 13 is referred to as a normal ground voltage.

  The lightning arrester 11 for power transmission includes a first support portion 21, a second support portion 22, a plurality of insulators 23, a first arc horn 24, a second arc horn 25, a lightning arrester 26, One gap 27 and a second gap 28. The first gap 27 is an example of a first discharge electrode. The second gap 28 is an example of a second discharge electrode.

  The first support portion 21 is made of a conductor such as metal, and includes a first attachment member 31 and a support arm 32. The first attachment member 31 is suspended from the support arm 15 of the steel tower 12. In other words, the first attachment member 31 is supported by the steel tower 12. The support arm 32 extends from the first mounting member 31 to the approximately lateral side.

  The second support portion 22 is made of a conductor such as metal and includes a second attachment member 35 and an electric wire clamp 36. In the present embodiment, the second mounting member 35 is located below the first mounting member 31. The electric wire clamp 36 is supported by the second attachment member 35 and supports the power transmission line 13.

  The plurality of insulators 23 are connected in series between the first attachment member 31 and the second attachment member 35. The plurality of insulators 23 connect the first mounting member 31 and the second mounting member 35 and insulate the first mounting member 31 and the second mounting member 35 from each other. The power transmission line 13 is fixed to the steel tower 12 via a plurality of insulators 23.

  The first arc horn 24 extends from the first mounting member 31. The first arc horn 24 extends, for example, from the first mounting member 31 to approximately the side and is bent downward.

  The second arc horn 25 extends from the second mounting member 35. The second arc horn 25 extends, for example, from the second mounting member 35 to the approximately lateral side and is bent upward. In other words, the second arc horn 25 extends toward the first arc horn 24. A predetermined interval is provided between the first arc horn 24 and the second arc horn 25.

  The lightning arrester 26 is attached to the support arm 32 of the first support portion 21. That is, the lightning arrester 26 is connected to the first support portion 21. The lightning arrester 26 has an insulating container 41. The container 41 houses, for example, a plurality of non-linear resistance elements that are stacked in series and mainly composed of zinc oxide. The lightning arrester 26 is not limited to this. The support arm 32 is electrically connected to one electrode terminal of the lightning arrester 26.

  The first gap 27 is electrically connected to the other electrode terminal of the lightning arrester 26. That is, the first gap 27 is connected to the first support portion 21 through the lightning arrester 26. The lightning arrester 26 normally insulates between the first gap 27 and the first support portion 21. For example, the first gap 27 extends downward from the lightning arrester 26.

  The second gap 28 extends from the second attachment member 35. In other words, the second gap 28 is connected to the second attachment member 35. The second gap 28 extends, for example, from the second mounting member 35 to the approximately side and is bent upward. In other words, the second gap 28 extends toward the first gap 27. A predetermined interval is provided between the first gap 27 and the second gap 28.

  By providing an interval between the first arc horn 24 and the second arc horn 25, the energization between the first arc horn 24 and the second arc horn 25 is interrupted. Similarly, by providing an interval between the first gap 27 and the second gap 28, energization between the first gap 27 and the second gap 28 is interrupted. Further, the insulator 23 insulates between the first attachment member 31 and the second attachment member 35. Therefore, the normal ground voltage is not applied to the first support portion 21 and the steel tower 12.

  FIG. 2 is a side view in which a part of the measuring apparatus 50 according to the first embodiment is cut away. FIG. 3 is a circuit diagram of the power transmission lightning arrester 11 and the measurement device 50 according to the first embodiment. With the measuring device 50 shown in FIG. 2, the leakage current of the lightning arrester 26 of the lightning arrester 11 for power transmission can be measured.

  As shown in FIGS. 2 and 3, the measuring device 50 includes a housing 51, a contact electrode 52, a measuring line 53, a fuse 54, a protective resistor 55, a measuring resistor 56, a voltmeter 57, and an attachment. Part 58. The contact electrode 52 is an example of a second connection electrode. The measurement line 53 is an example of a first connection electrode. The fuse 54 is an example of an element and a fuse. The protective resistor 55 is an example of an element and a first resistor. The measurement resistor 56 is an example of a second resistor and a measurement resistor.

  The casing 51 shown in FIG. 2 is made of an insulating material. The housing 51 includes an extending part 61 and a guide part 62. The extending part 61 is formed in a substantially cylindrical shape. The guide part 62 is provided at one end in the longitudinal direction of the extension part 61.

  The guide part 62 is formed, for example, in the shape of a truncated cone whose inner diameter increases as the distance from the extension part 61 increases. The guide part 62 may be formed in other shapes. The end of the guide part 62 is opened. For this reason, an opening 63 whose cross-sectional area decreases as it approaches the extension 61 is provided in the guide 62.

  The contact electrode 52 is provided at one end in the longitudinal direction of the extending portion 61. The contact electrode 52 is exposed to the outside of the housing 51 through the opening 63. The opening 63 is formed so that the cross-sectional area decreases as the contact electrode 52 is approached.

  The measurement line 53 is a conducting wire extending from the other end portion in the longitudinal direction of the extending portion 61. A part of the measurement line 53 may be covered with an insulating film. As shown in FIG. 1, the measurement line 53 is electrically connected to the first gap 27.

  As shown in FIG. 3, the fuse 54 is provided inside the housing 51. The fuse 54 is provided between the contact electrode 52 and the measurement line 53. The fuse 54 is blown when a predetermined voltage is applied, and the electrical connection between the contact electrode 52 and the measurement line 53 is cut off. For example, the fuse 54 blows when a normal ground voltage is applied.

  The protective resistor 55 is provided between the contact electrode 52 and the measurement line 53. The protective resistor 55 is provided between the fuse 54 and the measurement line 53, for example. Note that the protective resistor 55 may be provided at another position.

  The protective resistor 55 of this embodiment is a variable resistor. The resistance value of the protective resistor 55 can vary between, for example, 0Ω and a resistance value substantially the same as the resistance value of the normal lightning arrester 26. In other words, the protective resistance 55 has substantially the same resistance value as that of the lightning arrester 26, and the resistance value of the protective resistance 55 can be reduced from substantially the same resistance value as that of the lightning arrester 26. Note that the resistance value of the protective resistor 55 may be fixed. The minimum resistance value of the protective resistor 55 may be set higher than 0Ω, and the maximum resistance value of the protective resistor 55 may be set higher than the resistance value of the lightning arrester 26.

  The measurement resistor 56 is provided between the contact electrode 52 and the measurement line 53. The measurement resistor 56 is provided between the protective resistor 55 and the measurement line 53, for example. Note that the measurement resistor 56 may be provided at another position. The resistance value of the measurement resistor 56 is sufficiently smaller than the resistance value of the normal lightning arrester 26, for example.

  One terminal of the voltmeter 57 is connected between the protective resistor 55 and the measurement resistor 56, and the other terminal of the voltmeter 57 is connected between the measurement resistor 56 and the measurement line 53. The voltmeter 57 measures a potential difference at both ends of the measurement resistor 56. In other words, the voltmeter 57 measures the voltage generated at the measuring resistor 56.

  As shown in FIG. 2, the attachment portion 58 includes a holding portion 65, a fixing portion 66, a connecting portion 67, and a moving portion 68. The holding unit 65 holds, for example, the extending portion 61 of the housing 51 so as to be movable in the longitudinal direction of the extending portion 61. The fixing portion 66 is, for example, a clamp that can be attached to the first gap 27. The connecting part 67 connects the holding part 65 and the fixing part 66. By attaching the fixing portion 66 to the first gap 27, the housing 51 is supported by the first gap 27 via the attachment portion 58.

  The moving unit 68 includes various mechanical elements such as a motor and a pinion. The pinion attached to the motor of the moving unit 68 engages with a rack provided on the surface 51 a of the housing 51. When the motor is driven, the moving unit 68 moves the casing 51 in the longitudinal direction of the extending portion 61. The moving unit 68 moves the contact electrode 52 accommodated in the housing 51 together with the housing 51. The moving unit 68 may move the housing 51 and the contact electrode 52 by other means.

  FIG. 4 is a block diagram functionally showing the configuration of the measuring apparatus 50 according to the first embodiment. As shown in FIG. 4, the measuring apparatus 50 further includes a control unit 71, a resistance driver 72, a movement driver 73, and a communication unit 74.

  The control unit 71 includes, for example, a control device such as a CPU provided in the measuring device 50, a storage device such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an external storage such as a nonvolatile memory. Device. The control unit 71 is realized, for example, when the CPU reads a program from the ROM and executes it.

  The control unit 71 controls the resistance driver 72, the movement driver 73, and the communication unit 74. Further, the control unit 71 acquires information from the voltmeter 57 and the communication unit 74. For example, the control unit 71 acquires information on the potential difference at both ends of the measurement resistor 56 from the voltmeter 57.

  The resistance driver 72 is driven by the control unit 71 to drive a mechanism that changes the resistance value of the protective resistor 55. For example, the resistance driver 72 changes the resistance value of the protective resistor 55 based on the signal input from the control unit 71.

  The movement driver 73 is driven by the control unit 71 to drive the movement unit 68. For example, the movement driver 73 moves the casing 51 and the contact electrode 52 by driving a motor of the movement unit 68 based on a signal input from the control unit 71.

  The communication unit 74 is controlled by the control unit 71 to communicate with an external device. For example, the communication unit 74 transmits information to an external device based on a signal input from the control unit 71. Further, the communication unit 74 receives a signal transmitted from an external device, and the control unit 71 acquires information on the signal from the communication unit 74. The communication unit 74 is, for example, an antenna for performing wireless communication with an external device. Note that the communication unit 74 may perform wired communication with an external device.

  FIG. 5 is a flowchart illustrating an example of a method for measuring the leakage current of the lightning arrester 11 for power transmission by the measuring device 50 according to the first embodiment. Hereinafter, an example of a method for measuring the leakage current of the lightning arrester 11 for power transmission by the measuring device 50 will be described with reference to FIG. In addition, the measuring method of the leakage current of the lightning arrester 11 for power transmission by the measuring apparatus 50 is not restricted to the method demonstrated below.

  First, an operator attaches the fixing portion 66 of the measuring device 50 to the first gap 27 of the lightning arrester 11 for power transmission. Further, the operator connects the measurement line 53 of the measurement device 50 to the first gap 27.

  FIG. 6 is a side view showing the measuring apparatus 50 attached to the first gap 27 of the first embodiment. As shown in FIG. 6, when attached to the first gap 27, the housing 51 of the measuring device 50 is located at the separation position P1. At the separation position P <b> 1, the contact electrode 52 accommodated in the housing 51 is separated from the second gap 28. For example, the distance between the contact electrode 52 and the second gap 28 is approximately the same as the distance between the first gap 27 and the second gap 28, but is not limited thereto.

  The normal ground voltage of the transmission line 13 is not applied to the first gap 27 connected to the first support portion 21. For this reason, the operator can safely attach the measuring device 50 to the first gap 27. For example, the operator safely attaches the measuring device 50 to the first gap 27 from a position away from the first gap 27 using a working instrument.

  For example, the worker transmits a radio signal to the communication unit 74 of the measuring device 50 from a position separated from the first gap 27 by a device such as a portable computer. When the control unit 71 acquires the signal received by the communication unit 74, the control unit 71 controls the movement driver 73 to move the casing 51 to the movement unit 68. By moving the casing 51, the contact electrode 52 accommodated in the casing 51 is also moved (S11).

  The moving unit 68 moves the housing 51 and the contact electrode 52 toward the distal end portion 28 a of the second gap 28. As the housing 51 moves, the distal end portion 28 a of the second gap 28 hits the inner peripheral surface of the opening 63 of the guide portion 62, for example. As the moving portion 68 further moves the casing 51, the tip end portion 28a of the second gap 28 is guided by the opening 63 and contacts the contact electrode 52 (S12). Note that the distal end portion 28 a may directly contact the contact electrode 52 without contacting the opening 63.

  As described above, the moving unit 68 moves the casing 51 to the connection position P2 in FIG. In the connection position P <b> 2, the contact electrode 52 accommodated in the housing 51 is connected to the second gap 28. When the second gap 28 contacts the contact electrode 52, the second gap 28 is electrically connected to the contact electrode 52 as shown in FIG. 3.

  When the contact electrode 52 is connected to the second gap 28, the power transmission line 13, the second support portion 22, the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measurement resistor 56, and the measurement line 53. The first gap 27, the lightning arrester 26, the first support 21 and the tower 12 are electrically connected in series. In other words, the first gap 27 and the second gap 28 are electrically connected by the measuring device 50.

  When the contact electrode 52 is connected to the second gap 28, the resistance value of the protective resistor 55 is substantially the same as the resistance value of the normal lightning arrester 26. For this reason, even if the lightning arrester 26 loses insulation due to, for example, failure or deterioration, the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measuring resistor 56, the measuring line 53, the first gap 27 and the lightning arrester 26 are suppressed from being applied with a large voltage. That is, the protective resistor 55 is connected to the first support 21 via the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measurement resistor 56, the measurement line 53, the first gap 27, and the lightning arrester 26. And the application of the voltage (normal ground voltage) of the power transmission line 13 to the tower 12 can be cut off.

  If the resistance value of the protective resistor 55 is set low, the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measuring resistor 56, the measuring line 53, the first gap 27, and the lightning arrester 26 are included. A large voltage may be applied. However, the fuse 54 is blown when a large voltage such as a normal ground voltage is applied. Therefore, the fuse 54 includes the first support 21 via the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measurement resistor 56, the measurement line 53, the first gap 27, and the lightning arrester 26. And the application of the voltage (normal ground voltage) of the power transmission line 13 to the tower 12 can be cut off.

  As described above, the protective resistor 55 and the fuse 54 cut off the application of the normal ground voltage to the first support portion 21 and the tower 12. That is, the protective resistor 55 and the fuse 54 suppress a ground fault through the measuring device 50.

  The protective resistor 55 and the fuse 54 may cut off the application of the normal ground voltage to the first support portion 21 and the tower 12. Therefore, the first support portion 21 and the tower 12 are connected via the second gap 28, the contact electrode 52, the fuse 54, the protective resistor 55, the measurement resistor 56, the measurement line 53, the first gap 27, and the lightning arrester 26. A voltage weaker than the normal ground voltage may be applied.

  Next, the control unit 71 measures the potential difference at both ends of the measurement resistor 56 with the voltmeter 57 (S13). In other words, the control unit 71 acquires the voltage generated in the measurement resistor 56 from the voltmeter 57.

  Next, the control unit 71 converts the voltage acquired from the voltmeter 57 into a current (S14). For example, the control unit 71 calculates the current value by using the voltage value acquired from the voltmeter 57 and the resistance value of the measurement resistor 56. Since the resistance value of the measurement resistor 56 is sufficiently smaller than the resistance value of the lightning arrester 26, the calculated current substantially indicates the leakage current of the lightning arrester 26. Thus, the control unit 71 measures the leakage current of the lightning arrester 26 from the second gap 28 electrically connected in series, the measurement device 50, the first gap 27, and the electricity flowing through the lightning arrester 26. In other words, the control unit 71 measures the leakage current from the potential difference at both ends of the measurement resistor 56.

  The voltage applied to the lightning arrester 26 is calculated from the voltage division ratio between the lightning arrester 26 and the protective resistor 55. For this reason, the leakage current calculated in S14 is a leakage current generated in the lightning arrester 26 when a voltage is applied to the lightning arrester 26.

  Next, the control unit 71 determines whether or not the calculated current exceeds a preset threshold value (S15). For example, when the lightning arrester 26 has failed or deteriorated, the calculated current may exceed a threshold value (S15: Yes). In this case, the control unit 71 determines that the lightning arrester 26 is abnormal, and, for example, controls the communication unit 74 to transmit a radio signal notifying the operator's device of the abnormality (S16). For example, the control unit 71 may turn on a warning lamp provided in the measurement device 50 or may emit a warning sound from a speaker provided in the measurement device 50.

  On the other hand, when the calculated current is lower than the threshold value (S15: No), the control unit 71 determines whether the resistance value of the protective resistor 55 is 0Ω (S17). When the resistance value of the protective resistor 55 is greater than 0Ω (S17: No), the control unit 71 controls the resistance driver 72 to reduce the resistance value of the protective resistor 55 (S18). When the resistance value of the protective resistor 55 is reduced, the control unit 71 measures the voltage of the measurement resistor 56 again (S13).

  The control unit 71 measures voltage (S13), calculates leakage current (S14), and resistance of the protective resistor 55 until the resistance value of the protective resistor 55 becomes 0Ω or until it is determined that the lightning arrester 26 is abnormal. The value reduction (S18) is repeated. When the resistance value of the protective resistor 55 becomes 0Ω (S17: Yes), the control unit 71 determines that the lightning arrester 26 is normal. For example, the control unit 71 controls the communication unit 74 to send a radio signal notifying the operator's device of normality. Transmit (S19).

  When determining whether the lightning arrester 26 is normal or abnormal (S16, S19), the control unit 71 controls the movement driver 73 to move the casing 51 and the contact electrode 52 to the movement unit 68 (S20). The moving unit 68 moves the housing 51 and the contact electrode 52 from the connection position P2 to the separation position P1. Thereby, the electrical connection between the first gap 27 and the second gap 28 is cut off, and the normal ground voltage is not applied to the measuring device 50 and the first gap 27. For example, when the operator removes the measuring device 50 from the first gap 27, the measurement of the leakage current of the lightning arrester for power transmission 11 is completed.

  When the abnormality of the lightning arrester 26 is determined, for example, replacement of the lightning arrester 26 is arranged. Further, according to the characteristics of the leakage current generated in the lightning arrester 26 when a voltage is applied to the lightning arrester 26, for example, a plan for updating the lightning arrester 26 is made.

  The control unit 71 stores the measurement result of the leakage current in, for example, a nonvolatile memory. For example, the measurement result of the leakage current may be used as a reference for maintenance and inspection of the lightning arrester 11 for power transmission by comparing with the measurement result of the past leakage current.

  Further, the control unit 71 controls the communication unit 74 to control the current resistance value of the protective resistor 55, the voltage measured by the voltmeter 57, and the calculated leakage current of the lightning arrester 26, for example. Send wirelessly to computer. Thereby, the operator can grasp | ascertain the state of the lightning arrester 26 in real time, for example, can stop the measurement of leakage current according to a condition. Further, the control unit 71 wirelessly transmits the measurement result of the leakage current.

  The control unit 71 measures the leakage current of the lightning arrester 26 using the measurement resistor 56 and the voltmeter 57, but may measure the leakage current of the lightning arrester 26 using the ammeter 78 shown in FIG. The ammeter 78 is an ammeter having a current transformer, and is clamped to the support arm 32 of the first support portion 21, for example. Thereby, the ammeter 78 measures the current of the support arm 32 as a leakage current.

  The ammeter 78 transmits, for example, a radio signal related to the current of the support arm 32 to the measurement device 50. The control unit 71 can acquire information on the current measured by the ammeter 78 by acquiring the signal from the communication unit 74.

  In order to discover damage and deterioration of the lightning arrester, not only the lightning arrester 26 of the present embodiment, the leakage current of the lightning arrester is measured. However, the voltage applied to the lightning arrester for measuring the leakage current is relatively high. For this reason, in order to measure the leakage current of the lightning arrester, for example, the lightning arrester is removed from the lightning arrester for power transmission and brought into a test facility, or a power source for applying a voltage to the lightning arrester may be prepared. However, when removing the lightning arrester from the lightning arrester for power transmission, the power system may be interrupted. Moreover, when the lightning arrester for power transmission is provided in a mountainous area, for example, it is difficult to prepare a power source for applying a voltage to the lightning arrester.

  In the measurement method of the lightning arrester 11 for power transmission according to the first embodiment, the first gap 27 and the second gap 28 are connected by the measurement device 50, so that the voltage from the power transmission line 13 is connected to the lightning arrester 26. Is applied. In this state, the leakage current of the lightning arrester 26 is measured from the electricity flowing through the second gap 28, the measuring device 50, the first gap 27, and the lightning arrester 26 that are electrically connected in series. Thereby, for example, it is easier to remove the lightning arrester 26 from the lightning arrester 11 for power transmission and to prepare a power source for applying a voltage to the lightning arrester 26 in order to measure the leakage current in the test facility. Leakage current can be measured.

  As described above, for example, since the leakage current of the lightning arrester 26 can be measured without a power failure of the power system, the leakage current of the lightning arrester 26 can be measured more easily. For this reason, before the lightning arrester 26 is deteriorated or failed, it is possible to systematically update the lightning arrester 26 to improve the reliability of the power grid.

  For example, if the first gap 27 and the second gap 28 are short-circuited in a state where the insulation performance of the lightning arrester 26 is lost due to deterioration or failure, the power system may be grounded. However, the voltage of the transmission line 13 (normal ground voltage) to the first support 21 via the second gap 28, the measurement device 50, the first gap 27, and the lightning arrester 26 that are electrically connected in series. A fuse 54 and a protective resistor 55 that can cut off the application are disposed between the first gap 27 and the second gap 28. For this reason, even if the insulation property of the lightning arrester 26 is lost, the ground fault of the power system is suppressed when the first gap 27 and the second gap 28 are electrically connected by the measuring device 50. The

  The measuring device 50 has a protective resistor 55 having substantially the same resistance value as that of the lightning arrester 26. By providing the protective resistor 55, the second gap 28, the measuring device 50, the first gap 27, and the lightning arrester 26 that are electrically connected in series are connected to the first support portion 21. Application of voltage (regular ground voltage) is suppressed. Therefore, even if the insulation property of the lightning arrester 26 is lost, the ground fault of the power system is suppressed when the first gap 27 and the second gap 28 are electrically connected by the measuring device 50. .

  The resistance value of the protective resistor 55 can be reduced from substantially the same resistance value as that of the lightning arrester 26. When the first gap 27 and the second gap 28 are electrically connected by the measuring device 50, the resistance value of the protective resistor 55 is set to substantially the same resistance value as that of the lightning arrester 26. System ground faults are suppressed. With the first and second gaps 27 and 28 connected, the resistance value of the protective resistor 55 is gradually reduced to 0Ω, so that the voltage applied to the lightning arrester 26 becomes the voltage of the transmission line 13 (regular ground voltage). ). When the leakage current of the lightning arrester 26 becomes larger than the threshold value, the ground fault of the power system is suppressed by stopping the reduction of the resistance value of the protective resistor 55. Thereby, it becomes possible to measure the leakage current by applying the normal ground voltage to the lightning arrester 26 more safely. Further, it is possible to measure the leakage current of the lightning arrester 26 when an arbitrary voltage is applied to the lightning arrester 26.

  A change in the characteristics of the lightning arrester 26 can be detected by measuring the leakage current of the lightning arrester 26 when an arbitrary voltage is applied to the lightning arrester 26. For example, the renewal time of the lightning arrester 26 can be efficiently calculated based on the change in the characteristics of the lightning arrester 26.

  In measuring the leakage current, first, the measuring device 50 is attached to the first gap 27 grounded by the tower 12. Then, the moving unit 68 moves the contact electrode 52 from a separation position P1 where the contact electrode 52 is separated from the second gap 28 to a connection position P2 where the contact electrode 52 is connected to the second gap 28. Thus, an operator who attaches the measuring device 50 to the first gap 27 can connect the first and second gaps 27 before the first and second gaps 27 and 28 are electrically connected by the measuring device 50. , 28 can be evacuated. Therefore, the leakage current can be measured more safely.

  The movement part 68 moves the contact electrode 52 from the separation position P1 to the connection position P2 by transmitting a signal from a position away from the measurement device 50. In this way, the first and second gaps 27 and 28 are electrically connected by the measuring device 50 by remotely operating the moving unit 68. Therefore, the leakage current can be measured more safely.

  The measuring device 50 includes an insulating casing 51 that is provided with an opening 63 that exposes the contact electrode 52 and whose cross-sectional area decreases as the contact electrode 52 is approached. As a result, even if the traveling direction of the contact electrode 52 and the casing 51 moved by the moving portion 68 is deviated from the second gap 28, the second gap 28 is guided to the contact electrode 52 by the opening 63. Therefore, the leakage current can be measured more easily. Since the casing 51 is insulative, even if the second gap 28 abuts against the edge of the opening 63, the occurrence of a short circuit between the second gap 28 and the casing 51 is suppressed.

  The measuring device 50 has a fuse 54 provided between the first gap 27 and the second gap 28. The voltage (normal ground voltage) of the transmission line 13 is applied to the first support portion 21 through the second gap 28, the measurement device 50, the first gap 27, and the lightning arrester 26 that are electrically connected in series. When the fuse 54 is blown, the application of the normal ground voltage to the first support portion 21 is suppressed. Therefore, even if the insulation property of the lightning arrester 26 is lost, the ground fault of the power system is suppressed when the first gap 27 and the second gap 28 are electrically connected by the measuring device 50. .

  Further, the measuring device 50 can measure the leakage current of the lightning arrester 26 by the fuse 54. For example, when the leakage current of the lightning arrester 26 increases due to deterioration or failure, the voltage applied to the fuse 54 increases. Therefore, it is possible to measure the leakage current of the lightning arrester 26 (deterioration or failure of the lightning arrester 26) depending on whether the fuse 54 is blown.

  The leakage current of the lightning arrester 26 is measured from the potential difference between the second gap 28, the measuring device 50, the first gap 27, and the measurement resistor 56 electrically connected in series to the lightning arrester 26. Thereby, the leakage current of the lightning arrester 26 is easily measured.

  The leakage current of the lightning arrester 26 may be measured by an ammeter 78 having a current transformer. Thereby, the leakage current of the lightning arrester 26 is easily measured.

  The ammeter 78 is attached to the support arm 32 of the first support portion 21. Thereby, compared with the case where the ammeter 78 is attached to the 1st gap 27, for example, it is suppressed that electromagnetic induction arises.

  In the first embodiment, the measuring device 50 is attached to the lightning arrester 11 for power transmission when measuring the leakage current of the lightning arrester 11 for power transmission. However, the measuring device 50 may be permanently attached to the lightning arrester 11 for power transmission. In this case, the distance between the contact electrode 52 and the first gap 27 of the measurement device 50 in the normal state is substantially the same as the distance between the first gap 27 and the second gap 28, or It is kept above.

  In the following, a second embodiment will be described with reference to FIGS. In the following description of the embodiment, components having the same functions as those already described are denoted by the same reference numerals as those described above, and further description may be omitted. In addition, a plurality of components to which the same reference numerals are attached do not necessarily have the same functions and properties, and may have different functions and properties according to each embodiment.

  FIG. 7 is a side view showing a lightning arrester 11 for power transmission according to the second embodiment. As illustrated in FIG. 7, the lightning arrester 11 for power transmission according to the second embodiment further includes a measurement unit 80. The measurement unit 80 is interposed between the support arm 32 of the first support unit 21 and the lightning arrester 26.

  FIG. 8 is a side view schematically showing a part of the lightning arrester 11 for power transmission according to the second embodiment. As shown in FIG. 8, the measurement unit 80 includes a first terminal unit 81, a second terminal unit 82, an insulation support unit 83, a disconnection unit 84, a measurement resistor 85, and a voltmeter 86. . The measurement resistor 85 is an example of a second resistor.

  The first terminal portion 81 is connected to the support arm 32 of the first support portion 21. The first terminal portion 81 includes a first connection terminal 81a and a first measurement terminal 81b. The second terminal portion 82 is electrically connected to one electrode terminal of the lightning arrester 26. The second terminal portion 82 includes a second connection terminal 82a and a second measurement terminal 82b.

  The insulating support portion 83 is made of an insulating material such as synthetic rubber. The insulating support portion 83 connects the first terminal portion 81 and the second terminal portion 82. In other words, the insulating support portion 83 supports the second terminal portion 82. Further, the insulating support portion 83 insulates the first terminal portion 81 and the second terminal portion 82 from each other.

  For example, the disconnecting portion 84 is rotatably attached to the first connection terminal 81 a of the first terminal portion 81. Note that the disconnecting portion 84 may be rotatably attached to the second connection terminal 82 a of the second terminal portion 82.

  As shown by the two-dot chain line in FIG. 8, the disconnecting portion 84 comes into contact with the second connecting terminal 82 a, whereby the first connecting terminal 81 a of the first terminal portion 81 and the second connecting portion 82 of the second terminal portion 82. The two connection terminals 82a are electrically connected. By turning the disconnection portion 84, the first connection terminal 81a of the first terminal portion 81 and the second connection terminal 82a of the second terminal portion 82 can be electrically disconnected. .

  The disconnection part 84 is opened when the leakage current of the lightning arrester 11 for power transmission is measured, and the first connection terminal 81 a of the first terminal part 81 and the second connection terminal 82 a of the second terminal part 82. Is electrically disconnected. The disconnection portion 84 is normally closed and electrically connects the first connection terminal 81a and the second connection terminal 82a.

  The measurement resistor 85 is provided between the first measurement terminal 81 b of the first terminal portion 81 and the second measurement terminal 82 b of the second terminal portion 82. In other words, the measurement resistor 85 is provided between the first support portion 21 and the lightning arrester 26. Thereby, the measurement resistor 85 electrically connects the first terminal portion 81 and the second terminal portion 82. The resistance value of the measurement resistor 85 is sufficiently smaller than the resistance value of the lightning arrester 26, for example.

  One terminal of the voltmeter 86 is connected between the first measurement terminal 81b and the measurement resistor 85, and the other terminal of the voltmeter 86 is connected between the measurement resistor 85 and the second measurement terminal 82b. Is done. The voltmeter 86 measures a potential difference at both ends of the measurement resistor 85. In other words, the voltmeter 86 measures the voltage generated at the measuring resistor 85.

  The measurement resistor 85 and the voltmeter 86 are attached to the power transmission lightning arrester 11 when the leakage current of the power transmission lightning arrester 11 is measured. Since the measurement resistor 85 and the voltmeter 86 are removed from the lightning arrester 11 during normal operation, the first measurement terminal 81b and the second measurement terminal 82b are electrically disconnected.

  The power transmission lightning arrester 11 further includes a guard 91. The guard 91 is an example of a relay unit. The guard 91 is a conducting wire, for example. The first end portion 91 a of the guard 91 is connected between the measurement resistor 85 and the support arm 32 of the first support portion 21. The second end portion 91 b of the guard 91 is connected to the surface 41 a of the container 41 of the lightning arrester 26. The guard 91 electrically connects the portion between the measurement resistor 85 and the support arm 32 and the surface 41 a of the container 41.

  The guard 91 is attached to the power transmission lightning arrester 11 when the leakage current of the power transmission lightning arrester 11 is measured. In a normal time, the guard 91 is removed from the power transmission lightning arrester 11.

  FIG. 9 is a circuit diagram of the power transmission lightning arrester 11 and the measuring device 50 according to the second embodiment. As shown in FIG. 9, the measuring device 50 of the second embodiment includes a casing 51, a contact electrode 52, a measurement line 53, a fuse 54, and a protective resistor 55, and the first embodiment. The measuring resistor 56 and the voltmeter 57 are not provided. The lightning arrester 11 for power transmission according to the second embodiment includes a measurement resistor 85 and a voltmeter 86 instead of the measurement resistor 56 and the voltmeter 57.

  In the second embodiment, the leakage current of the power transmission lightning arrester 11 is measured by the measurement device 50 as follows. In addition, the measuring method of the leakage current of the lightning arrester 11 for power transmission is not restricted to the method demonstrated below.

  First, as in the first embodiment, an operator attaches the fixing portion 66 of the measuring device 50 to the first gap 27 of the lightning arrester 11 for power transmission. Further, the operator connects the measurement line 53 of the measurement device 50 to the first gap 27.

  Next, the operator opens the disconnection portion 84. As a result, the first connection terminal 81 a of the first terminal portion 81 and the second connection terminal 82 a of the second terminal portion 82 are electrically disconnected. Note that the disconnecting portion 84 may be opened before the measuring device 50 is attached to the first gap 27.

  In addition, the worker attaches the measurement resistor 85 to the first measurement terminal 81 b of the first terminal portion 81 and the second measurement terminal 82 b of the second terminal portion 82. Further, the worker attaches the guard 91 to the portion between the measurement resistor 85 and the support arm 32 and the surface 41 a of the container 41.

  Next, as in the first embodiment, the contact electrode 52 is moved (S11), and the contact electrode 52 contacts the second gap 28 (S12). Thereby, the power transmission line 13, the second support portion 22, the second gap 28, the contact electrode 52, the fuse 54, the protective resistance 55, the measurement line 53, the first gap 27, the lightning arrester 26, the measurement resistance 85, the first The support part 21 and the steel tower 12 are electrically connected in series.

  Thereafter, the control unit 71 measures the voltage (S13) and calculates the leakage current until the resistance value of the protective resistor 55 reaches 0Ω or until it is determined that the lightning arrester 26 is abnormal, as in the first embodiment. (S14) and reduction of the resistance value of the protective resistor 55 (S18) are repeated. When determining whether the lightning arrester 26 is normal or abnormal (S16, S19), the control unit 71 controls the movement driver 73 to move the casing 51 and the contact electrode 52 to the movement unit 68 (S20). For example, when the operator removes the measuring device 50 from the first gap 27, the measurement of the leakage current of the lightning arrester for power transmission 11 is completed.

  When the surface 41a of the container 41 of the lightning arrester 26 is soiled, the material of the surface 41a is deteriorated, or the surface 41a is wetted by rain, for example, the current flowing through the surface 41a increases. Since the leakage current of the lightning arrester 26 is very small, the current flowing through the surface 41a may affect the measured leakage current.

  In the method for measuring leakage current of the lightning arrester 11 for power transmission according to the second embodiment, the measurement resistor 85 is provided between the first support portion 21 and the lightning arrester 26. The first end portion 91 a of the guard 91 is connected between the measurement resistor 85 and the first support portion 21. The second end portion 91 b of the guard 91 is connected to the surface 41 a of the container 41 of the lightning arrester 26. Thereby, the current flowing through the surface 41 a of the lightning arrester 26 does not flow through the measurement resistor 85 provided between the first support part 21 and the lightning arrester 26, and passes through the guard 91 and the first support part 21. Flowing into. In other words, the current flowing through the non-linear resistance element of the lightning arrester 26 and the current flowing through the surface 41a of the lightning arrester 26 are separated. Thereby, it is suppressed that the electric current which flows through the surface 41a of the lightning arrester 26 is erroneously measured as the leakage current of the lightning arrester 26.

  According to at least one embodiment described above, the leakage current of the lightning arrester is measured from the electricity flowing in the second discharge electrode, the connection device, the first discharge electrode, and the lightning arrester that are electrically connected in series. . Thereby, the leakage current of a lightning arrester can be measured easily.

  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 novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, in the above embodiment, the measuring device 50 measures the leakage current of the lightning arrester 26. However, for example, the worker may calculate the leakage current of the lightning arrester 26 based on the measured values of the voltmeters 57 and 86.

  Moreover, the lightning arrester 11 for power transmission in the said embodiment is extended in a substantially vertical direction. However, the power transmission lightning arrester 11 may extend in a substantially horizontal direction, for example.

  DESCRIPTION OF SYMBOLS 11 ... Lightning arrester for power transmission, 12 ... Steel tower, 13 ... Transmission line, 21 ... 1st support part, 22 ... 2nd support part, 23 ... insulator, 26 ... Lightning arrester, 27 ... 1st gap, 28 ... 1st Two gaps, 41 ... container, 41a ... surface, 50 ... measuring device, 51 ... housing, 52 ... contact electrode, 53 ... measuring line, 54 ... fuse, 55 ... protective resistance, 56 ... measuring resistor, 57 ... voltmeter , 63 ... opening, 68 ... moving part, 78 ... ammeter, 85 ... measurement resistance, 86 ... voltmeter, 91 ... guard, 91a ... first end, 91b ... second end, P1 ... separated position , P2: Connection position.

Claims (11)

A first support portion supported by a grounded object; a second support portion supporting a power transmission line; an insulator connecting the first support portion and the second support portion; and the first support. A leakage current measuring method for a lightning arrester for power transmission, comprising: a lightning arrester connected to a part; a first discharge electrode connected to the lightning arrester; and a second discharge electrode connected to the second support part. There,
Electrically connecting the first discharge electrode and the second discharge electrode by a connecting device;
Measuring the leakage current of the lightning arrester from electricity flowing in the second discharge electrode, the connection device, the first discharge electrode, and the lightning arrester electrically connected in series;
Comprising
The connection device is provided between the first discharge electrode and the second discharge electrode, and is electrically connected in series. The second discharge electrode, the connection device, and the first discharge electrode. And an element capable of cutting off the application of the voltage of the power transmission line to the first support part via the lightning arrester,
Leakage current measurement method.   The leakage current measuring method according to claim 1, wherein the element includes a first resistor having substantially the same resistance value as the lightning arrester.   The leakage current measuring method according to claim 2, wherein the resistance value of the first resistor can be reduced from substantially the same resistance value as that of the lightning arrester. Attaching the connection device to the first discharge electrode;
A first connection electrode connectable to the first discharge electrode; a second connection electrode connectable to the second discharge electrode; and a moving unit for moving the second connection electrode. From the separation position where the second connection electrode is separated from the second discharge electrode, to the connection position where the second connection electrode is connected to the second discharge electrode, in the moving part of the connection device, Moving the second connection electrode;
The leakage current measuring method according to any one of claims 1 to 3, further comprising:   The leakage current measuring method according to claim 4, wherein the moving unit moves the second connection electrode from the separated position to the connection position by transmitting a signal from a position separated from the connection device. The connection device has an insulating casing provided with an opening that exposes the second connection electrode and whose cross-sectional area decreases as it approaches the second connection electrode;
The moving unit moves the casing together with the second connection electrode;
The leakage current measuring method according to claim 5.   The leakage current measuring method according to claim 1, wherein the element has a fuse provided between the first discharge electrode and the second discharge electrode. Both ends of a second resistor having a resistance value smaller than that of the lightning arrester and electrically connected in series to the second discharge electrode, the connection device, the first discharge electrode, and the lightning arrester Measuring the potential difference at
Further comprising
The lightning arrester leakage current is measured from the potential difference,
The leakage current measuring method according to claim 1.   The lightning arrester for power transmission includes a first end connected between the second resistor provided between the first support and the lightning arrester and the first support. The leakage current measuring method according to claim 8, further comprising: a relay portion having a second end portion connected to the surface of the lightning arrester.   The leakage current measuring method according to claim 1, wherein the leakage current of the lightning arrester is measured by an ammeter having a current transformer. A first support portion supported by a grounded object; a second support portion supporting a power transmission line; an insulator connecting the first support portion and the second support portion; and the first support. Leakage current of the lightning arrester in a lightning arrester for power transmission comprising: a lightning arrester connected to a part; a first discharge electrode connected to the lightning arrester; and a second discharge electrode connected to the second support part. A measuring device capable of measuring
A first connection electrode connectable to the first discharge electrode;
A second connection electrode connectable to the second discharge electrode;
Having a resistance value smaller than the resistance value of the lightning arrester, and a measurement resistance provided between the first connection electrode and the second connection electrode;
A voltmeter for measuring a potential difference at both ends of the measurement resistor;
The second discharge electrode, the second connection electrode, the measurement resistor, the first resistance, which are provided between the first connection electrode and the second connection electrode and are electrically connected in series An element capable of cutting off the application of the voltage of the power transmission line to the first support via the connection electrode, the first discharge electrode, and the lightning arrester;
A measuring apparatus comprising:

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