JP2006098086A - Lightning strike current measuring instrument and lightning strike current instrumentation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightning strike current measuring instrument and a lightning strike current instrumentation system for measurement of correct detection time by well receiving the long wave standard radio waves. <P>SOLUTION: The lightning strike current measuring instrument 100 is constituted such that the CPU 8a is connected with a radio controlled clock 7, and the time data is inputted to the CPU 8a from the radio controlled clock 7, wherein when the radio controlled clock 7 receives the long wave standard radio wave, switches the frequency of the operation clock of the CPU 8 a from the regular operation frequency to the operation frequency for reception lower than the carrier frequency of the standard radio waves of long wave. The lightning strike current instrumentation system 1000 is composed of the lightning strike current measuring instrument 100. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lightning current measuring device and a lightning current measuring system for measuring a lightning surge current value.

  When taking measures against lightning, it is necessary to grasp the lightning surge current value at the time of lightning. Since this lightning strike is a natural phenomenon and is greatly influenced by weather conditions, it is difficult to theoretically estimate the lightning surge current value. Therefore, the estimated lightning surge current is usually estimated by acquiring a number of actual measured lightning surge current values due to actual lightning strikes, and analyzing these measured lightning surge current values using statistical methods. The value is used for lightning protection.

As a conventional technology for such a lightning current measuring device, for example, in the conventional technology described in Patent Document 1 (title of the lightning current detection device) relating to the patent application of the present applicant, a lightning surge current path is provided. A Rogowski coil is placed so that it surrounds, a rectifier circuit is connected between both ends of the Rogowski coil, a charging circuit that holds the output voltage of the rectifier circuit, and a trigger when the output voltage of the rectifier circuit exceeds a predetermined value A trigger circuit for generating a signal, and when the trigger signal is generated, the number of times the trigger signal is generated is accumulated and stored, and the current time is stored as the detection time, and the voltage value held in the charging circuit is stored. It is regarded as a lightning surge current value, A / D converted and stored, and the current value is integrated to obtain an integrated current value.
In this lightning current detection device of Patent Document 1, the number of occurrences, detection time (that is, lightning time), current value, and integrated current value thereof are output.

JP 2001-349908 A (paragraph numbers 0010, 0011, FIG. 2)

  The lightning current detection device of Patent Document 1 measures the detection time (lightning strike time), but uses a clock with a built-in CPU. However, in a clock with a built-in CPU, errors are accumulated and the time is not accurate, and it cannot be used in an application where the detection time needs to be accurately measured.

Other lightning current detection devices according to the prior art have attempted to accurately measure the detection time (lightning strike time) using a quartz clock mounted therein.
However, the quartz watch has a large time lag due to changes in the ambient temperature, and the lightning current detection device installed at a location where the difference in temperature between the natural environment is large may cause the detection time to be inaccurate.

Therefore, the present inventor has come up with the idea that an accurate detection time can be obtained without being affected by the surrounding environment by mounting a radio clock on the lightning current detection device.
However, in lightning current detectors equipped with radio clocks, the reception sensitivity may not be high when receiving long wave standard radio waves (long wave band JJY: East Japan 40kHz long wave standard radio wave, West Japan 60kHz long wave standard radio wave). I found out.

As a result of investigating this phenomenon, the reception sensitivity is lowered due to self-interference due to high frequency noise caused by the operating frequency (4 MHz) of the CPU operating clock used in the apparatus main body.
Therefore, it is conceivable to lower the operating frequency of the CPU operating clock. In this case, however, it is not necessary to lower the operating frequency. The frequency of the nth harmonic or nth subharmonic by the CPU operating clock is the long wave standard. Even when it matches the carrier frequency of radio waves (40 kHz long wave standard radio wave in eastern Japan, 60 kHz long wave standard radio wave in west Japan), the reception sensitivity is slightly reduced. In particular, the primary harmonic (when the operating frequency of the CPU operating clock is 20 kHz, the primary harmonic is 40 kHz, which is the same as the carrier frequency of the long-wave standard radio wave in eastern Japan) or the primary subharmonic (primary when the operating frequency of the CPU operating clock is 80 kHz). The harmonics are 40 kHz, which is the same as the carrier frequency of the long wave standard radio wave in eastern Japan.
When such interference occurs, time data cannot be received, and it is necessary to eliminate the interference.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lightning current measuring device and a lightning lightning that can accurately detect a long detection time so that long wave standard radio waves can be received well. It is to provide a current measurement system.

A lightning current measuring device according to claim 1 of the present invention is
A lightning current measuring device in which a radio clock is connected to a CPU and time data is input from the radio clock to the CPU,
When the radio timepiece receives a long wave standard radio wave, the radio clock includes a means for switching the CPU operating clock from a normal operating frequency to a receiving operating frequency lower than the carrier frequency of the long wave standard radio wave.

A lightning current measuring device according to claim 2 of the present invention is
In the lightning current measuring device according to claim 1,
The receiving operation frequency of the CPU operation clock is set so that the frequency of the nth harmonic and the nth subharmonic generated by the operation clock of the receiving operation frequency do not match the carrier frequency of the long wave standard radio wave. It is characterized by doing.

A lightning current measuring device according to claim 3 of the present invention is
In the lightning current measuring device according to claim 1 or 2,
The carrier frequency of the long wave standard radio wave is higher than the operation frequency for receiving the operation clock of the CPU, and the carrier frequency of the long wave standard radio wave is lower than the frequency of the first harmonic by the operation clock of the operation frequency for receiving the CPU, An operation frequency for receiving the operation clock of the CPU is set.

A lightning current measuring device according to claim 4 of the present invention is
In the lightning current measuring device according to any one of claims 1 to 3,
The CPU switches the CPU operating clock to the receiving operating frequency before the radio timepiece receives the long wave standard radio wave, and receives it. After the radio clock finishes receiving the long wave standard radio wave, the CPU clock is operated normally. It is a means for returning to the frequency.

A lightning current measuring device according to claim 5 of the present invention is
In the lightning current measuring device according to any one of claims 1 to 4,
A detector that is arranged so as to surround a lightning surge current path and generates an induced voltage corresponding to the magnitude of the lightning surge current;
An integrator that integrates the induced voltage signal from the detector and outputs an integrated voltage signal;
A rectifier that rectifies the integrated voltage signal from the integrator and outputs a rectified voltage signal;
An attenuator that attenuates the rectified voltage signal from the rectifier and outputs a lightning voltage signal;
A charging unit that holds a lightning voltage signal output from the attenuator;
A trigger circuit that generates a trigger signal when the rectified voltage signal from the rectifier exceeds a predetermined voltage value;
A radio clock that outputs time data;
It has a function as the CPU, and when a trigger signal is generated, the trigger signal is integrated and stored as the number of occurrences, and the current time is stored as a detection time with reference to time data of the radio clock, and a charging unit A central processing unit for storing the lightning surge current value while regarding the voltage value of the lightning voltage signal held by the A / D converter as a lightning surge current value;
A display that displays the number of occurrences, detection time, lightning surge current value and accumulated current value stored in memory,
The output section that outputs the number of occurrences, detection time, lightning surge current value and its accumulated current value to the outside,
It is characterized by providing.

A lightning current measuring system according to claim 6 of the present invention is
A lightning current measuring device according to claim 5;
An alarm output unit connected to the lightning current measuring device;
With other alarm output units in remote locations,
It is characterized in that the measurement data can be transmitted to a remote alarm output unit for use.

  According to the present invention as described above, it is possible to provide a lightning current measuring device and a lightning current measuring system capable of detecting a precise detection time so that long wave standard radio waves can be received well.

The best mode for carrying out the lightning current measuring device and the lightning current measuring system of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a lightning current measuring device of this embodiment.
As shown in FIG. 1, in the lightning current measuring apparatus 100, a detection unit (specifically a Rogowski coil) 1 and a main body 50 are connected via a cable. The main body 50 includes an integrating circuit 2, a rectifier 3, an attenuator 4, a charging unit 5, a discharging unit 6, a radio clock 7, a central processing unit 8, a trigger circuit 9, a liquid crystal display 10, a D / D conversion unit 11, E A / O conversion unit 12, a test switch 13, a display switch 14, and a battery 15 are provided. The central processing unit 8 includes a CPU 8a, an A / D conversion unit 8b, and a memory 8c.

Subsequently, each of these configurations will be described.
The detector (Logoowski coil) 1 is a small and lightweight waterproof type that can be easily attached to the tower base of the tower, and is placed so as to surround the lightning surge current path. An induced voltage is generated and an induced voltage signal is output. This induced voltage signal is input to the integrating circuit 2 via a cable or the like.
The integrating circuit 2 integrates the induced voltage signal, which is a differentiated waveform output from the detection unit 1, converts it to an integrated voltage signal, and outputs the integrated voltage signal.
The rectifier 3 converts the integrated voltage signal into a rectified voltage signal that is a unidirectional voltage value having polarity and outputs the rectified voltage signal.

The attenuator 4 attenuates the rectified voltage signal from the rectifier 3, converts it into a lightning voltage signal that falls within a predetermined voltage range so as not to be saturated in the subsequent circuit, and outputs the signal.
The charging unit 5 stores the voltage of the lightning voltage signal output from the attenuator 4. This lightning voltage signal is held until the CPU 8a reads it.
The discharge unit 6 resets the charging unit 5 by discharging a lightning voltage signal stored in the charging unit 5 by a signal from the CPU 8a, which will be described later.
The radio clock 7 receives a long wave standard radio wave (long wave band JJY: East Japan 40kHz long wave standard radio wave, West Japan 60kHz long wave standard radio wave), decodes the time information included in the long wave standard radio wave, and generates time data. Send to CPU8a. The CPU 8a generates detection time data based on the time data. This makes the lightning surge entry time accurate.

  In the central processing unit 8, an A / D conversion unit 8b and a memory 8c are connected to the CPU 8a. Normally, the CPU 8a minimizes battery consumption in the sleep mode, and is activated by a trigger signal generated during a lightning strike. The CPU 8a first counts this trigger signal input. This count is integrated and stored as the number of occurrences. Subsequently, the CPU 8a refers to the time data from the radio clock 7 and stores the current time as detected time data. Further, the lightning voltage signal of the charging unit 5 is converted into lightning voltage data by the A / D conversion unit 8b and read out, and the lightning voltage data is regarded as lightning surge current data and registered. Then, the CPU 8a collects the count data, detection time data, lightning surge current data, and integrated current value data for the lightning surge current value as measurement data, stores this measurement data in the memory 8c, and converts it to E / O conversion. After outputting to the unit 12, a signal is sent to the discharging unit 6 to discharge the charging unit 5, and then the sleep mode is entered again. The measurement data can include various other data. The processing of the CPU 8a will be described later using a flowchart.

The trigger circuit 9 detects that a voltage has been generated when the rectified voltage signal from the rectifier 3 exceeds a predetermined voltage value, and generates and outputs a trigger signal for starting up the CPU 8a.
The liquid crystal display 10 receives measurement data from the CPU 8a and displays the number of occurrences, detection time, lightning surge current value, and integrated current value.
The D / D conversion unit 11 is connected to the CPU 8 a and converts the battery 15, which is a DC power supply, according to the power supply circuit of the liquid crystal display 10.

The E / O converter 12 is connected to the CPU 8a, converts measurement data output from the CPU 8a into an optical signal, and outputs the optical signal to the outside.
The test switch 13 is a switch that is connected to the CPU 8a and tests the detection operation of the entire circuit.
The display switch 14 is a switch that is connected to the CPU 8a and causes the liquid crystal display 10 to perform display.

  Next, each part will be described with reference to the drawings. FIG. 2 is a flowchart for explaining lightning current measurement processing. The lightning current measuring device 100 performs measurement processing according to a flow as shown in FIG. When the operation is started by pressing a reset switch (not shown), the CPU 8a starts initialization (step S1 in FIG. 2) or stabilizes the power supply (step S2 in FIG. 2), and then receives time data. Is initialized (step S3 in FIG. 2). Since the long wave standard radio wave (long wave band JJY) mentioned above is either the 40 kHz long wave standard radio wave of eastern Japan or the 60 kHz long wave standard radio wave of western Japan, the initial setting from the carrier frequency of the received long wave standard radio wave is for 40 kHz. Select between initial setting and initial setting for 60 kHz. In the present embodiment, it is assumed that 40 kHz long wave standard radio wave is set for East Japan for concrete explanation.

Subsequently, a clock change process is started (step S4 in FIG. 2). First, the CPU 8a changes the operation clock input from the built-in oscillator by switching from the normal operation frequency of 4 MHz to the reception operation frequency of 32 kHz (step S5 in FIG. 2).
As described above, when the radio timepiece 7 receives the long wave standard radio wave, the normal operation frequency (4 MHz) of the CPU 8a is switched to the reception operating frequency (32 kHz) lower than the carrier frequency of the long wave standard radio wave, and is received. The influence of the high frequency noise which has been a problem at the normal operating frequency of 4 MHz is eliminated, and good reception is realized in this respect.
Further, the first harmonic (frequency is 64 kHz) and the first subharmonic (frequency is 16 kHz) are generated by the operation clock of the CPU 8a which is the reception operating frequency (32 kHz). Therefore, the first harmonic and the first subharmonic do not affect the reception, and a good reception can be realized in this respect as well.
It should be noted that the frequency of the long wave standard radio wave (64 kHz) between the reception operating frequency (32 kHz) based on the operation clock of the CPU 8a and the first harmonic (64 kHz) of the operation clock based on the reception operating frequency as in this embodiment. 40 kHz) to prevent interference and ensure a sufficiently high frequency as an operation clock of the CPU.
The setting that satisfies these conditions improves the reception sensitivity and makes it possible to detect an accurate lightning strike time.

Subsequently, a command for receiving time data is transmitted to the radio timepiece 7 to perform reception processing (step S6 in FIG. 2). The CPU 8a obtains time data output from the radio timepiece 7.
The CPU 8a changes the operating clock input from the built-in oscillator by switching from the receiving operating frequency of 32 kHz to the normal operating frequency of 4 MHz (step S7 in FIG. 2).
Subsequently, the CPU 8a performs a test operation process (step S8 in FIG. 2). This is a process for obtaining measurement data as described above.

Subsequently, the CPU 8a performs display operation processing (step S9 in FIG. 2). This is the measurement data display process as described above. The number of occurrences, detection time, lightning surge current value, and integrated current value are displayed as described above.
Subsequently, the CPU 8a performs task processing (step S10 in FIG. 2). Specifically, LCD control, surge current display, battery level display, battery indicator display, key scan, etc. are performed.
Then, it is determined whether or not to continue (step S11 in FIG. 2). When continuing, the process jumps to the head of step S4, and when not continuing, the process proceeds to step S12 to enter the sleep mode (step in FIG. 2). S12).

Although the operation is stopped in the sleep mode, when an input is made from the outside, the operation jumps to the beginning of step S4, performs the operations from step S4 to step S11, and stops again in the sleep mode. Such an operation is repeated.
An example of the input from the outside is a trigger signal for starting the CPU 8a when the trigger circuit 9 detects that a voltage is generated in the rectifier 3 when a surge current flows. Further, the input by the test switch 13 and the display switch 14 is also an external input. This is performed at the time of operation for operation confirmation by the worker.
According to such a lightning strike current measuring apparatus 100, there is an advantage that the time when the lightning strike is measured becomes accurate.

Next, a lightning current measuring system using the lightning current measuring device 100 will be described with reference to the drawings. FIG. 3 is a system configuration diagram which is an example of a lightning current measurement system 1000 according to this embodiment, and FIG. 4 is an explanatory diagram of an actual installation example of the lightning current measurement system 1000.
The lightning current measurement system 1000 includes a lightning current measurement device 100, an alarm output unit 200, a personal computer 300, exchanges 400 and 500, an alarm output unit 600, and a personal computer 700.

  The measurement data output from the lightning current measuring device 100 is transmitted to the alarm output unit 200. The alarm output unit 200 outputs an alarm by voice or display. In addition, measurement data is output to the personal computer 300 and the exchange 400 connected via USB. The personal computer 300 can store measurement data (text file).

The measurement data is transferred to the alarm output unit 600 via the exchange 400, the telephone line, and the exchange 500. In this case, it passes through the exchanges 400 and 500, that is, with analog signals in mind. For example, the measurement data is output to the alarm output unit 600 through the server by the Internet protocol, or laid for a long distance. The measurement data may be output to the alarm output unit 600 via an optical cable.
In addition, it is possible to use existing communication lines such as wireless, mobile phone, PHS, etc., depending on the local infrastructure conditions, you can select one communication line by telephone line, optical cable, wireless, mobile phone, PHS, Alternatively, a plurality of communication lines may be combined such that a certain part is wireless and another part is a telephone line.

  Measurement data from such a distance is transmitted to the alarm output unit 600 via an optical cable. Similarly to the alarm output unit 200, the alarm output unit 600 outputs an alarm by voice or display. Also, the measurement data is output to the personal computer 700 connected via USB. The personal computer 700 can store measurement data (text file).

In an actual installation example of such a lightning current measurement system 1000, for example, as shown in FIG. 4, a detection unit (Logoowski coil) is provided so as to surround a tower base of a summit radio relay station that is a lightning surge current path. 1 is penetrated, and the main body 50 is arranged near the tower base of the steel tower. Then, the optical cable connected to the main body 50 is drawn into the shelter of the summit wireless relay station and connected to the alarm output unit 200. A personal computer 300 is connected to the alarm output unit 200 by USB. The alarm output unit 200 is connected to an alarm output unit 600 of a remote electric station far away via an optical cable. A personal computer 700 is connected to the alarm output unit 600 of the remote electric station.
According to such a lightning current measurement system 1000, alarm output can be confirmed even at a distant place, and measurement data can be collected.

It is a block diagram of the lightning current measuring device of the best form for implementing this invention. It is a flowchart explaining a lightning current measurement process. BRIEF DESCRIPTION OF THE DRAWINGS It is a system block diagram which is an example of the lightning current measurement system of the best form for implementing this invention. It is explanatory drawing of the actual installation example of the lightning current measuring system of the best form for implementing this invention.

Explanation of symbols

100: Lightning current measuring device 1: Detection unit (Logoowski coil)
2: Integration circuit 3: Rectifier 4: Attenuator 5: Charging unit 6: Discharging unit 7: Radio clock 8: Central processing unit 8a: CPU
8b: A / D converter 8c: Memory 9: Trigger circuit 10: Liquid crystal display 11: D / D converter 12: E / O converter 13: Test switch 14: Display switch 15: Battery 50: Body 200: Alarm Output unit 300: PC 400: Switch 500: Switch 600: Alarm output unit 700: PC

Claims (6)

A lightning current measuring device in which a radio clock is connected to a CPU and time data is input from the radio clock to the CPU,
A lightning strike characterized by comprising means for switching and receiving a CPU operating clock from a normal operating frequency to a receiving operating frequency lower than a carrier frequency of the long wave standard radio wave when the radio timepiece receives a long wave standard radio wave Current measuring device. In the lightning current measuring device according to claim 1,
The receiving operation frequency of the CPU operation clock is set so that the frequency of the nth harmonic and the nth subharmonic generated by the operation clock of the receiving operation frequency do not match the carrier frequency of the long wave standard radio wave. A lightning current measuring device characterized by: In the lightning current measuring device according to claim 1 or 2,
The carrier frequency of the long wave standard radio wave is higher than the operation frequency for receiving the operation clock of the CPU, and the carrier frequency of the long wave standard radio wave is lower than the frequency of the first harmonic by the operation clock of the operation frequency for receiving the CPU, An apparatus for measuring lightning current, wherein an operating frequency for receiving an operation clock of the CPU is set. In the lightning current measuring device according to any one of claims 1 to 3,
The CPU switches the CPU operating clock to the receiving operating frequency before the radio timepiece receives the long wave standard radio wave, and receives it. After the radio clock finishes receiving the long wave standard radio wave, the CPU clock is operated normally. A lightning current measuring device characterized by being a means for returning to a frequency. In the lightning current measuring device according to any one of claims 1 to 4,
A detector that is arranged so as to surround a lightning surge current path and generates an induced voltage corresponding to the magnitude of the lightning surge current;
An integrator that integrates the induced voltage signal from the detector and outputs an integrated voltage signal;
A rectifier that rectifies the integrated voltage signal from the integrator and outputs a rectified voltage signal;
An attenuator that attenuates the rectified voltage signal from the rectifier and outputs a lightning voltage signal;
A charging unit that holds a lightning voltage signal output from the attenuator;
A trigger circuit that generates a trigger signal when the rectified voltage signal from the rectifier exceeds a predetermined voltage value;
A radio clock that outputs time data;
It has a function as the CPU, and when a trigger signal is generated, the trigger signal is integrated and stored as the number of occurrences, and the current time is stored as a detection time with reference to time data of the radio clock, and a charging unit A central processing unit for storing the lightning surge current value while regarding the voltage value of the lightning voltage signal held by the A / D converter as a lightning surge current value;
A display that displays the number of occurrences, detection time, lightning surge current value and accumulated current value stored in memory,
The output section that outputs the number of occurrences, detection time, lightning surge current value and its accumulated current value to the outside,
A lightning current measuring device comprising: A lightning current measuring device according to claim 5;
An alarm output unit connected to the lightning current measuring device;
With other alarm output units in remote locations,
A lightning current measurement system characterized in that the measurement data is transmitted to a remote alarm output unit for use.

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