JP2014176240A - Arrestor monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arrestor monitoring system capable of monitoring processing energy or a temperature of an arrestor.SOLUTION: The arrestor monitoring system comprises: a discharging current acquisition section for acquiring a discharging current value of an arrestor including a nonlinear resistor; a current waveform calculation section for calculating a current waveform indicating a relation between the discharging current value acquired by the discharging current acquisition section and a time; a voltage waveform calculation section for calculating a voltage waveform from the current waveform calculated by the current waveform calculation section and characteristics of the nonlinear resistor; a processing energy calculation section for calculating processing energy of the arrestor from the current waveform calculated by the current waveform calculation section and the voltage waveform calculated by the voltage waveform calculation section; and an arrestor temperature calculation section for calculating a temperature of the arrestor on the basis of the processing energy calculated by the processing energy calculation section.

Description

  Embodiments described herein relate generally to a lightning arrester monitoring system.

  Electrical facilities such as substations are provided with lightning arresters to protect major equipment such as transformers from overvoltages such as lightning surges. This lightning arrester is connected between the terminal or bus of the device to be protected and the ground, and has a function of immediately discharging the generated overvoltage to the ground and returning it to its original state without causing a power failure.

  Such a lightning arrester is basically configured by connecting non-linear resistors in series between lines. Non-linear resistors are non-linear resistors whose resistance value decreases significantly as the voltage increases. The main component is zinc oxide, which has superior protection characteristics and overvoltage handling capability as the power system voltage increases. The resistor is used.

  As a method of measuring lightning current, a method of measuring using a magnetic steel piece is known. In the lightning arrester, the peak value of the discharge current is recorded by a magnetic steel piece or the like for deterioration diagnosis or the like.

  However, if the lightning arrester receives continuous lightning strikes such as several times per second, the non-linear resistor may be damaged with energy lower than the withstand value of the original lightning arrester. This is because, when a part of the non-linear resistor generates heat, it receives the next electric shock before it is made uniform by heat conduction, thereby deteriorating the balance of heat generation distribution and the balance of thermal expansion.

  Therefore, it is required to monitor the processing energy and temperature of the lightning arrester.

JP 2001-35708 A

  In order to solve these problems, an embodiment of the present invention provides a lightning arrester monitoring system capable of monitoring the processing energy and temperature of a lightning arrester.

  To achieve the above object, a lightning arrester monitoring system according to an embodiment includes a discharge current acquisition unit that acquires a discharge current value of a lightning arrester having a non-linear resistor, and a discharge current value and time acquired by the discharge current acquisition unit. A current waveform calculation unit that calculates a current waveform indicating a relationship between the current waveform, a current waveform calculated by the current waveform calculation unit, and a voltage waveform calculation unit that calculates a voltage waveform from the characteristics of the nonlinear resistor, A processing energy calculation unit that calculates processing energy of the lightning arrester from the current waveform calculated by the current waveform calculation unit and the voltage waveform calculated by the voltage waveform calculation unit, and is calculated by the processing energy calculation unit. And a lightning arrester temperature calculation unit for calculating the temperature of the lightning arrester based on the processing energy.

The whole system figure which shows the relationship between the lightning arrester monitoring system which concerns on this embodiment, and a peripheral device. The block diagram which shows the structure of the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment. The block diagram which shows the structure of the memory | storage part in the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment. An example of characteristic DB in the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment. The flowchart which shows operation | movement of the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment. An example of the current waveform calculated by the current waveform calculation program in the monitoring device of the lightning arrester monitoring system according to the present embodiment. An example of the voltage waveform calculated by the voltage waveform calculation program in the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment. An example of the processing energy waveform calculated by the processing energy calculation program in the monitoring apparatus of the lightning arrester monitoring system which concerns on this embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an overall system diagram showing the relationship between a lightning arrester monitoring system and peripheral devices according to the present embodiment.

  The lightning arrester monitoring system 1 is a system for monitoring the lightning arrester 2 and includes a monitoring device 100 and an O / E (Optical / Electrical) converter 10. The lightning arrester 2 uses a non-linear resistor 3 that exhibits high resistance characteristics under normal voltage and exhibits low resistance characteristics when an abnormal voltage is applied due to electric shock or the like, and between the power system 4 and the ground 5. Connected to. An example of the non-linear resistor 3 is a zinc oxide element.

  The low voltage portion of the non-linear resistor 3 and the ground 5 are connected by a ground line 6, and a current transformer 7 that detects the discharge current of the lightning arrester 2 is provided between the ground lines 6.

  One current transformer 7 is provided with a wide detection range capable of detecting a current of several tens and several hundreds kA such as a lightning current due to a lightning strike from a current of mA order such as a leakage current in a steady operation. Alternatively, a plurality of units may be provided and used depending on the value of the detected current.

  When an abnormal voltage is generated in the power system 4 due to lightning or the like, the discharge current of the lightning arrester 2 flows to the ground 5 via the ground line 6 to limit the abnormal voltage. The same applies not only to the discharge current due to lightning strike, but also to the leakage current during steady operation and the switching surge current during system operation.

  The current transformer 7 and an E / O (Electrical / Optical) converter 8 are connected via a transmission line 9a, and the E / O converter 8 and the O / E converter 10 are connected via a transmission line 9b. The transmission line 9b is, for example, an optical fiber. Further, the monitoring device 100 and the O / E converter 10 are connected via a transmission line 9c.

  For example, the E / O converter 8 is placed at a site where the lightning arrester 2 is installed, and the O / E converter 10 is placed in a monitoring room. The E / O converter 8 and the O / E converter 10 perform electro-optical conversion, so that the site and the monitoring room are insulated, and the safety of the monitoring room is maintained even when the lightning arrester 2 is hit by lightning. . Moreover, the influence of external noise can be suppressed by using an optical fiber for the transmission line 9b.

  The current transformer 7 acquires the discharge current value of the lightning arrester 2. The acquired discharge current value is output as an electric signal to the E / O converter 8 via the transmission line 9a.

  The E / O converter 8 acquires the electrical signal of the discharge current value from the current transformer 7 and converts it into an optical signal. The converted optical signal is output to the O / E converter 10 via the transmission line 9b.

  The O / E converter 10 acquires an optical signal from the E / O converter 8 and converts it into an electrical signal. The converted electrical signal is output to the monitoring apparatus 100 via the transmission line 9c.

  The monitoring device 100 acquires the discharge current value of the lightning arrester 2 as an electrical signal from the O / E converter 10.

  FIG. 2 is a block diagram showing the configuration of the monitoring device of the lightning arrester monitoring system according to the present embodiment.

  As shown in FIG. 2, the monitoring apparatus 100 includes a calculation processing unit 11, a communication IF (interface) 12, an output IF 13, a display unit 14, and a storage unit 15. In addition, an IF for mounting an external storage device such as a USB memory may be provided.

  The arithmetic processing unit 11 is a processor such as a CPU (Central Processing Unit) that reads out each program stored in the storage unit 15 and performs arithmetic processing. A plurality of arithmetic processing units 11 may be provided according to functions. Moreover, you may provide the built-in memory.

  The communication IF 12 is a communication device or a communication unit that exchanges signals via the transmission line 9b.

  The output IF 13 is an interface that connects the display unit 14 and the monitoring apparatus 100. The display unit 14 may be controlled from the arithmetic processing unit 11 via the output IF 13, or display control is performed by an LSI (Large Scale Integration) (GPU: Graphics Processing Unit) that performs drawing processing such as a graphic board. Also good. An example of the display control function is a decoding function for decoding image data. The monitoring device 100 may not use the output IF 13 and the display unit 14 may be directly connected to the inside of the monitoring device 100.

  The display unit 14 is a monitor such as a liquid crystal display, an organic EL (Electro Luminescence) display, or a plasma display. In addition, you may provide the function to emit a sound. In this embodiment, it is installed outside the monitoring device 100, but may be incorporated in the monitoring device 100.

  The storage unit 15 is a non-volatile storage device such as a hard disk drive (HDD) or storage means. In addition, a semiconductor memory such as a flash memory may be used without being limited to the nonvolatile storage unit, or a storage medium in which the semiconductor memory and the HDD are combined may be used.

  FIG. 3 is a block diagram illustrating a configuration of a storage unit in the monitoring device of the lightning arrester monitoring system according to the present embodiment.

  As shown in FIG. 3, the storage unit 15 includes a discharge current value acquisition program 31, a current waveform calculation program 32, a characteristic DB (Data Base) 33, and a voltage waveform calculation that are used for processing in the arithmetic processing unit 11. A program 34, a processing energy calculation program 35, a lightning arrester temperature calculation program 36, a processing energy determination program 37, a temperature determination program 38, and a warning output program 39 are stored.

  The discharge current value acquisition program 31 is a discharge current value acquisition unit that causes the arithmetic processing unit 11 to execute a function of acquiring the discharge current value of the lightning arrester 2 from the O / E converter 10 via the communication IF 12.

  The current waveform calculation program 32 is a current waveform calculation unit that causes the arithmetic processing unit 11 to execute a function of calculating a current waveform indicating the relationship between the discharge current value and time from the discharge current value acquired by the discharge current value acquisition program 31. . This calculation of the current waveform may be performed by, for example, a digital oscillogram.

  As shown in FIG. 4, the characteristic DB 33 stores characteristic data indicating the relationship between the current and voltage of the non-linear resistor 3.

  The voltage waveform calculation program 34 causes the arithmetic processing unit 11 to execute the function of calculating the current waveform calculated by the current waveform calculation program 32 and the voltage waveform indicating the relationship between the voltage value and time from the characteristic DB 33. It is.

  The processing energy calculation program 35 executes a function for calculating the processing energy processed by the lightning arrester 2 from the current waveform calculated by the current waveform calculation program 32 and the voltage waveform calculated by the voltage waveform calculation program 34 in the arithmetic processing unit 11. A processing energy calculation unit.

  The lightning arrester temperature calculation program 36 is a lightning arrester temperature calculation unit that causes the arithmetic processing unit 11 to execute a function of calculating the current temperature of the lightning arrester 2 based on the processing energy calculated by the processing energy calculation program 35.

  The processing energy determination program 37 is a processing energy determination unit that causes the arithmetic processing unit 11 to execute a function of determining whether the processing energy calculated by the processing energy calculation program 35 exceeds a preset processing energy threshold.

  The temperature determination program 38 is a temperature determination unit that causes the arithmetic processing unit 11 to execute a function of determining whether or not the current temperature of the lightning arrester 2 calculated by the lightning arrester temperature calculation program 36 has exceeded a preset temperature threshold value. .

  When the processing energy determination program 37 determines that the processing energy has exceeded a preset processing energy threshold, or the temperature determination program 38 indicates that the temperature of the lightning arrester 2 has exceeded a preset temperature threshold, the warning output program 39 This is a warning output unit that causes the arithmetic processing unit 11 to execute a function of outputting a warning to the display unit 14 via the output IF 13 when determined.

  Next, the operation of each component will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the monitoring device of the lightning arrester monitoring system according to this embodiment.

  The discharge current value acquisition program 31 acquires the discharge current value of the lightning arrester 2 from the O / E converter 10 via the communication IF 12 (step S101).

  The current waveform calculation program 32 calculates a current waveform indicating the relationship between the discharge current value and time from the discharge current value acquired by the discharge current value acquisition program 31 (step S102).

  An example of the current waveform calculated by the current waveform calculation program 32 is shown in FIG. FIG. 6 shows an example when a lightning strike is received at time t1.

  The voltage waveform calculation program 34 calculates a voltage waveform indicating the relationship between the voltage value and time from the current waveform calculated by the current waveform calculation program 32 and the characteristic DB 33 (step S103).

  As shown in FIG. 4, a voltage value v corresponding to the current value i is calculated from the characteristic DB 33, and a voltage waveform corresponding to the current waveform calculated by the current waveform calculation program 32 is calculated.

  An example of the voltage waveform calculated by the voltage waveform calculation program 34 is shown in FIG. FIG. 7 shows an example when a lightning strike is received at time t1.

  The processing energy calculation program 35 calculates the processing energy processed by the lightning arrester 2 from the current waveform calculated by the current waveform calculation program 32 and the voltage waveform calculated by the voltage waveform calculation program 34 (step S104).

Specifically, the processing energy E is obtained by time integration of the product of the current value i and the voltage value v as shown in Equation (1).

The processing energy calculation program 35 may calculate the processing energy as a waveform as shown in FIG. FIG. 8 shows an example when a lightning strike is received at time t1.

  The processing energy calculation program 35 may calculate an energy value that can be processed in the future by the lightning arrester 2 from the processing energy processed by the lightning arrester 2.

  The lightning arrester temperature calculation program 36 calculates the current temperature of the lightning arrester 2 based on the processing energy calculated by the processing energy calculation program 35 (step S105).

  The temperature change Δt of the lightning arrester 2 is calculated by Equation (2), and the current temperature of the lightning arrester 2 is calculated from the initial temperature of the lightning arrester 2 and the temperature change Δt.

Δt = E / Cv (2)
Here, E is the processing energy of the lightning arrester 2 and Cv is the constant volume specific heat.

  The processing energy determination program 37 determines whether or not the processing energy calculated by the processing energy calculation program 35 exceeds a preset processing energy threshold, and the temperature determination program 38 is calculated by the lightning arrester temperature calculation program 36. It is determined whether or not the current temperature of the lightning arrester 2 has exceeded a preset temperature threshold (step S106).

  An example of the processing energy threshold is the short-time withstand value of the non-linear resistor 3 obtained by performing a destructive test using a test circuit that simulates multiple lightning. Here, the short-time withstand value is an energy value processed by the lightning arrester 2 within a preset time.

  The temperature determination program 38 may determine whether or not the temperature change Δt such as the temperature rise value of the lightning arrester 2 calculated by the lightning arrester temperature calculation program 36 has exceeded a preset temperature threshold value.

  As an example of the temperature threshold, a local temperature of the non-linear resistor 3 or a local temperature rise value obtained from the heat generation distribution and the thermal conductivity of the non-linear resistor 3 by analytical calculation can be cited.

  The warning output program 39 sets the temperature threshold at which the current temperature of the lightning arrester 2 is set in advance when the processing energy is determined to exceed the preset processing energy threshold by the processing energy determination program 37 or by the temperature determination program 38. If it is determined that it has been exceeded (YES in step S106), a warning is output to the display unit 14 via the output IF 13 (step S107).

  When the processing energy calculated by the processing energy calculation program 35 approaches the processing energy threshold value, or the current temperature of the lightning arrester 2 or the temperature change Δt calculated by the lightning arrester temperature calculation program 36 is used as the warning output program 39. When approaching, a warning may be output to the display unit 14 via the output IF 13.

  The display unit 14 displays the warning output from the warning output program 39 (step S108).

  In addition to the warning output from the warning output program 39, the display unit 14 includes the processing energy value of the lightning arrester 2 calculated by the processing energy calculation program 35, the current temperature of the lightning arrester 2 calculated by the lightning arrester temperature calculation program 36, Alternatively, the temperature change Δt may be displayed. Further, the current waveform calculated by the current waveform calculation program 32 shown in FIG. 6 or the voltage waveform calculated by the voltage waveform calculation program 34 shown in FIG. 7 may be displayed.

  The processing energy value of the lightning arrester 2 displayed by the display unit 14 may be a waveform indicating the relationship between the processing energy value and time as shown in FIG. 8, and the maximum energy processed by the lightning arrester 2 within a preset time. It may be a value. Moreover, the energy value processed by the lightning arrester 2 at the end within a preset time may be used.

  Here, if the preset time is t2, the maximum energy value processed by the arrester 2 within the preset time indicates E1 in FIG. 8, and the surge arrester ends at the end of the preset time. The energy value processed by 2 indicates E2 in FIG.

  Further, when an energy value that can be processed in the future by the lightning arrester 2 is calculated by the processing energy calculation program 35, it may be displayed on the display unit 14.

  The time interval displayed on the display unit 14 can be arbitrarily set by the operator.

  The display content of the display unit 14 may be configured to be output to other lightning arrester monitoring systems, computers, terminal devices, etc. via the communication IF 12.

  As described above, according to the lightning arrester monitoring system according to the present embodiment, the processing energy and temperature of the lightning arrester 2 can be monitored, so that overload is caused not only by a single lightning surge but also by a plurality of lightning surges. It is possible to detect a lightning arrester that may have been damaged early. By detecting lightning arresters that may have deteriorated or damaged at an early stage, ground faults can be prevented.

  Furthermore, monitoring in real time is possible by changing the time interval displayed on the display unit 14.

  Note that the various functions and processing procedures described in the present embodiment may be realized by hardware.

  This embodiment is presented as an example and is not intended to limit the scope of the invention. The present embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the invention described in the claims and equivalents thereof as well as included in the scope and spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Lightning arrester monitoring system 2 ... Lightning arrester 3 ... Non-linear resistor 4 ... Electric power system 5 ... Ground 6 ... Ground line 7 ... Current transformer 8 ... E / O (Electrical / Optical) converter 9a, 9b, 9c ... Transmission path DESCRIPTION OF SYMBOLS 10 ... O / E (Optical / Electrical) converter 11 ... Operation processing part 12 ... Communication IF (interface)
13 ... Output IF
DESCRIPTION OF SYMBOLS 14 ... Display part 15 ... Storage part 31 ... Discharge current value acquisition program 32 ... Current waveform calculation program 33 ... Characteristic DB (Data Base: database)
34 ... Voltage waveform calculation program 35 ... Processing energy calculation program 36 ... Arrester temperature calculation program 37 ... Processing energy determination program 38 ... Temperature determination program 39 ... Warning output program

Claims (5)

A discharge current value acquisition unit for acquiring a discharge current value of a lightning arrester having a non-linear resistor;
A current waveform calculation unit that calculates a current waveform indicating a relationship between the discharge current value acquired by the discharge current acquisition unit and time; and
A voltage waveform calculating unit that calculates a voltage waveform from the current waveform calculated by the current waveform calculating unit and characteristics of the non-linear resistor;
A processing energy calculation unit that calculates processing energy of the lightning arrester from the current waveform calculated by the current waveform calculation unit and the voltage waveform calculated by the voltage waveform calculation unit;
A lightning arrester monitoring system comprising: a lightning arrester temperature calculation unit that calculates the temperature of the lightning arrester based on the processing energy calculated by the processing energy calculation unit.   The lightning arrester monitoring system according to claim 1, further comprising a processing energy determination unit that determines whether the processing energy calculated by the processing energy calculation unit exceeds a preset processing energy threshold.   The lightning arrester monitoring system according to claim 1 or 2, further comprising a temperature determination unit that determines whether or not the temperature calculated by the lightning arrester temperature calculation unit exceeds a preset temperature threshold value.   A warning when the processing energy determination unit determines that the processing energy exceeds a preset processing energy threshold, or when the temperature determination unit determines that the temperature exceeds a preset temperature threshold The lightning arrester monitoring system of Claim 2 or Claim 3 which further has a display part which displays. It further has a converter that acquires an optical signal of a discharge current value of a lightning arrester having a non-linear resistor and converts it into an electrical signal,
The lightning arrester monitoring system according to any one of claims 1 to 4, wherein the discharge current value acquisition unit acquires the discharge current value converted into an electric signal by the converter.

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