JP2008064473A - Water level measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the possibility of damaging water gauges due to the intrusion of indirect lightning strokes to electric supply lines. <P>SOLUTION: A water level measuring system includes a water gauge which is provided for the inside of a river for outputting water level measurement data measured on the basis of electric power accumulated in a prescribed electricity accumulation means to the outside as light signals and which is provided with an indirect lightning stroke protecting means; a power supply device provided separately from the water gauge for supplying electric power for the water gauge via a prescribed electric supply line; an optical fiber for transmission having one end connected to the water gauge for transmitting light signals; and a data processing device connected to the other end of the optical fiber for transmission for acquiring water level measurement data by receiving light signals and for applying prescribed processing to the water level measurement data. The indirect lightning stroke protecting means detects the supply of power from the power supply device for the water gauge and leaves the electric supply line open in the case where the supply of power for the water gage is not in a supplying state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water level measurement system for measuring various outdoor water levels.

As a system for measuring the water level of a river (water level measurement system), it is composed of a water level meter, a power supply device for supplying power to the water level meter, and a data processing device for processing measurement data supplied from the water level meter There is. In such a water level measurement system, the water level gauge is provided in a submerged state in the river, the power feeding device is provided in a relay box located slightly away from the river, and the data processing device is provided with a water level gauge and a relay. It is located in a station building that is separated from the box and manages the river.
Such a water level measurement system is widely known among those skilled in the art as a well-known technique and as an implementation technique, but the applicant does not grasp the publicly known literature describing the water level measurement system at the present time. .

  By the way, in the water level measurement system that measures the water level of an outdoor object (river) like the river water level measurement system, it is necessary to ensure the resistance to lightning. As part of this, the river water level measurement system transmits the measurement data obtained by the water level gauge to the central office using optical fiber. The power supply device in the junction box is used to supply power to the water level gauge. Since this is carried out via an electric wire (feeding line), there is a risk that an induced lightning will enter the feeding line and damage the water level gauge.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reduce the possibility of damage to a water level meter due to intrusion of an induced lightning into a power supply line.

  In order to achieve the above object, in the present invention, as a first solution means, water level measurement data provided in a river and measured based on the power stored in a predetermined power storage means is output to the outside as an optical signal. A water level meter provided with an induced lightning protection means, a power supply device that is provided apart from the water level meter and supplies power to the water level meter via a predetermined power supply line, and one end connected to the water level meter, Data processing for transmitting an optical signal and transmitting the optical signal to the other end of the optical fiber for transmission, receiving the optical signal to obtain water level measurement data, and performing predetermined processing on the water level measurement data The induced lightning protection means employs means for detecting power feeding from the power feeding device to the water level gauge and opening the power supply line when not in the power feeding state.

Further, as the second solving means, in the first means, a means that the power storage means is an electric double layer capacitor is adopted.

  As a third solving means, in the first or second means, the water level meter includes a water level sensor that detects the water level as a repetition frequency of the pulse signal, an edge detection circuit that detects an edge of the pulse signal, an edge An electric / optical converter that converts the output of the detection circuit into an optical signal and outputs the optical signal to the transmission optical fiber is employed.

  As a fourth solving means, in any one of the first to third means, the induced lightning protection means adopts means for switching the open / connected state of the feeder line by using a semiconductor switch.

According to the present invention, since the power supply line is opened when it is not in the power supply state by the induced lightning protection means, the risk of damage to the water level gauge due to the intrusion of the induced lightning into the power supply line is reduced in the case of not being in the power supply state. be able to.
In addition, since an electric double layer capacitor that can be charged at a higher speed than a normal secondary battery is used as a storage means, the time required for one charge can be shortened compared to the case of a secondary battery. It is possible to reduce the probability that the induced lightning enters the power supply line, and thus it is possible to reduce the possibility of the water level gauge being damaged by the induced lightning.
Furthermore, a pulse signal having a repetition frequency corresponding to the water level output from the water level sensor is converted into an edge detection signal using an edge detection circuit, and the edge detection signal is converted into an optical signal by an electric / optical converter. Since the signal is output to the transmission optical fiber, it is possible to reduce the power consumed by the electrical / optical converter as compared with the case where the pulse signal is directly converted into the optical signal. Therefore, since the number of times the water level gauge is charged can be reduced, it is possible to reduce the probability that the induced lightning will enter the power supply line in the power supply state, and thus reduce the possibility of the water level gauge being damaged by the induced lightning. Can do.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram showing an overall configuration of a water level measurement system according to the present embodiment. As shown in the figure, the water level measurement system includes a water level gauge 1, a power feeding device 2, a power feeding line 3, a transmission optical fiber 4, a data receiving circuit 5, and a data processing device 6.
FIG. 2 is a circuit diagram showing the detailed configuration of the main part of the power supply system and power supply device 2 of the water level gauge 1, and FIG. 3 shows the essential components of the data output system of the water level gauge 1 and the data receiving circuit 5 in the station building. It is a block diagram which shows a part detailed structure.

  The water level meter 1 is provided so as to be submerged in the river as shown in the figure. The water level meter 1 measures the water level of the river based on the electric power supplied from the power supply device 2 through the power supply line 3, and uses the water level measurement data. Output to one end of the transmission optical fiber 4. As shown in FIGS. 2 and 3, the water level meter 1 includes a protection circuit 1a (inductive lightning protection means), a regulator 1b, an electric double layer capacitor 1c, a water level sensor 1d, an edge detection circuit 1m, and an E / O. A converter 1n is provided. In addition, each component of the water level meter 1 will be described later.

  The power feeding device 2 is provided in a relay box disposed at a certain distance from the water level gauge 1 as shown in FIG. 1, and as shown in FIG. 2, a power supply device 2a, switches 2b and 2b, a relay drive circuit 2c and timer 2d. The power supply device 2a converts commercial AC power (for example, AC 100V) into DC power of about 10V and outputs it to the switches 2b and 2b. The switches 2b and 2b are contact switches that are opened and closed by a relay drive circuit 2c, and are provided as a pair between the output end of the power supply device 2a and the output end of the power supply device 2 (between the power supply device 2a and the power supply line 3). It has been. The relay drive circuit 2c drives the switches 2b and 2b based on a control signal input from the timer 2d. The timer 2d always counts the time, and outputs the control signal to the relay drive circuit 2c every time a preset time (set time) is counted.

  As shown in FIG. 2, the feeder 3 is a pair of electric wires, one end is connected to the output end of the feeder 2 (the output end of the switches 2b and 2b), and the other end is the input end of the water level gauge 1 (power reception). End). The transmission optical fiber 4 is the same as the quartz fiber used in general optical communication, and one end is connected to the data output end of the water level gauge 1 (the output end of the E / O converter 1n), The other end is connected to the input end of the data receiving circuit 5 (the input end of the O / E converter 5a).

  As shown in FIG. 3, the data receiving circuit 5 includes an O / E converter 5a and a 1/2 frequency divider 5b, and receives an optical signal input from the water level gauge 1 via the transmission optical fiber 4. Then, the water level measurement data obtained by the reception is output to the data processing device 6. Details of the O / E converter 5a and the 1/2 frequency divider 5b will be described later for convenience of explanation. The data processing device 6 converts the water level measurement data input from the data receiving circuit 5 into a predetermined format and stores it sequentially in time series.

Next, details of the water level gauge 1 and the data receiving circuit 5 will be described.
As shown in FIG. 2, the protection circuit 1a of the water level gauge 1 includes a lightning arrester 1e, resistors 1f, 1g, and 1k, a diode 1h, and photocouplers 1i and 1j. The lightning arrester 1e, the resistors 1f and 1g, and the diode 1h are circuit elements that realize an abnormal voltage surge function to surge an abnormal high voltage due to induced lightning, and the resistor 1k and the photocouplers 1i and 1j are power supply devices. Connection switching for detecting the power supply state (power supply / non-power supply) from the power supply line 2 to the water level gauge 1 and switching the connection state (connection / non-connection) of the power supply line 3 to the water level meter 1 according to this power supply state It is a circuit element that realizes the function.

  The lightning arrester 1e is provided between the other ends of the power supply line 3 as shown in the figure, one end of the resistor 1f is connected to the other end of the one power supply line 3, and one end of the resistor 1g is connected to the other power supply line 3. The diode 1h has a sword terminal connected to the other end of the resistor 1f and an anode terminal connected to the other end of the resistor 1f. The resistor 1k has one end connected to the other end of the resistor 1f (that is, the cathode terminal of the diode 1h) and the other end connected to the photodiode anode terminal of the photocoupler 1i. In one photocoupler 1i, the cathode terminal of the photodiode is the anode terminal of the photodiode in the other photocoupler 1j, the drain terminal of the phototransistor is the other end of the resistor 1f, and the source terminal of the phototransistor is one of the regulator 1b. Are connected to the input terminals respectively. In the photocoupler 1j, the cathode terminal of the photodiode and the drain terminal of the phototransistor are connected to the other end of the resistor 1g (that is, the anode terminal of the diode 1h), and the source terminal of the phototransistor is connected to the other input terminal of the regulator 1b. ing.

  The regulator 1b converts the DC power of about 10V input from the power supply device 2 through the power supply line 3 and the protection circuit 1a into DC power of about 5V, and outputs it to the electric double layer capacitor 1c. The electric double layer capacitor 1c has one end connected to one output end of the regulator 1b and the other end connected to the other output end of the regulator 1b. When the DC power is supplied from the regulator 1b, the DC power In the state where the charge is charged based on the above and the supply of DC power from the regulator 1b is stopped, the stored charge is discharged and supplied to the water level sensor 1d as power. In the state where DC power is supplied from the regulator 1b to the electric double layer capacitor 1c, a part of the DC power is charged to the electric double layer capacitor 1c and the rest is supplied to the water level sensor 1d as power.

  The water level sensor 1d is thus operated by the electric power supplied from the electric double layer capacitor 1c or the regulator 1b, detects the water level of the river, and detects a pulse signal having a repetition frequency corresponding to the water level as a detection signal. To the edge detection circuit 1m. This detection signal is a pulse signal having a duty ratio (duty ratio) of approximately 50%, and the edge detection circuit 1m detects the rising edge of such a detection pulse signal, and the time width is extremely narrow at the rising edge. An edge detection signal in which pulses are arranged (duty ratio is about 5%) is output to the E / O converter 1n. The E / O converter 1n converts the edge detection signal (electric signal) into a light detection signal and outputs the light detection signal to the transmission optical fiber 4.

  The O / E converter 5a in the data receiving circuit 5 receives the photodetection signal (photoelectric conversion) to reproduce the edge detection signal and outputs it to the ½ frequency divider 5b. The 1/2 frequency divider 5b divides the edge detection signal by 1/2 to generate a frequency conversion pulse signal having a 1/2 repetition frequency of the detection pulse signal output from the water level sensor 1d. To the data processing device 6.

  Next, a time-series operation of the water level measurement system configured as described above will be described in detail.

  First, the power feeding operation from the power feeding device 2 to the water level gauge 1 will be described with reference to FIG. 2. The timer 2d of the power feeding device 2 always keeps time, and is controlled whenever a predetermined set time is reached. The signal is output to the relay drive circuit 2c for a predetermined time. For example, the timer 2d outputs a control signal to the relay drive circuit 2c for 2 minutes every 3 hours, so that the relay drive circuit 2c closes the switch 2b for 2 minutes every 3 hours, In other periods, the switch 2b is opened. In other words, the water level meter 1 is supplied with DC power of 10 V through the feeder line 3 for 2 minutes every 3 hours.

  In the state where 10V DC power is supplied from the power supply device 2 to the water level gauge 1, a potential difference of 10V naturally occurs between the pair of power supply lines 3. For example, one power supply line 3 (resistor 1f side) is provided. In the case of a potential of 10 V, the other feeder line 3 (resistor 1 g side) has a potential of 0 V. Therefore, each of the photodiodes of the photocouplers 1 i and 1 j connected in series between the feeder lines 3 is all. As a result, the other end of each power supply line 3 is simply connected to each input of the regulator 1b. On the other hand, when there is no power supply from the power supply device 2 to the water level gauge 1, since no potential difference is generated between the pair of power supply lines 3, each photodiode of the photocouplers 1i and 1j is in an OFF state. The other end of each power supply line 3 is in an open state.

  That is, in the water level measurement system, each power line 3 is connected to the water level gauge 1 only during a period in which DC power is supplied from the power supply device 2 to the water level gauge 1, and each power line 3 is connected to the water level during a power supply stop period. It is in a state of being disconnected from the total 1. Further, the high voltage of the feeder 3 due to the induced lightning is surged by an abnormal voltage surge function by the lightning arrester 1e, resistors 1f and 1g and the diode 1h. Therefore, in this state, even if induced lightning enters the feeder line 3, each element constituting the water level gauge 1, such as the regulator 1b, the electric double layer capacitor 1c, and the water level sensor 1d, includes a resistor 1k, a photocoupler 1i, 1j is further protected by both the connection switching function and the abnormal voltage surge function, and the possibility of breakdown or failure is reduced.

  Further, the DC power fed from the power feeding device 2 to the water level gauge 1 is converted into a DC voltage of 5V by the regulator 1b and charged in the electric double layer capacitor 1c. As mentioned above, it is only 2 minutes in 3 hours, and is extremely short. Such a short feeding time is due to the fact that the electric double layer capacitor 1c is used as the power storage means, which has an extremely short charging time compared to a normal secondary battery, and an edge detection circuit 1m is provided as will be described later. It is realized by this.

  That is, when a secondary battery is used as the power storage means, it is necessary to set the charge time for one time to about 1 hour. In this case, a lightning strike occurs during charging for the long charge time, and induced lightning. Is likely to enter the feeder line 3. On the other hand, in the water level measurement system, since the electric double layer capacitor 1c is used as a power storage means, one charging time is 2 minutes, which is extremely short compared to the secondary battery, and thus induced lightning enters the feeder line 3. The probability of doing is low. Therefore, it is possible to reduce the failure probability due to the induced lightning of the water level gauge 1.

  Subsequently, the transmission operation of the water level measurement data will be described with reference to FIG. 3. The water level sensor 1d outputs a pulse signal having a repetition frequency corresponding to the water level of the river as a detection signal. This detection signal is a pulse signal having a duty ratio of about 50%, but is converted into an edge detection signal by the edge detection circuit 1m, and then converted into a light detection signal by the E / O converter 1n. Is transmitted to the station and recorded.

  Here, in the present water level measurement system, a detection signal having a duty ratio of about 50% is not directly supplied to the E / O converter 1n and converted into an optical signal, but the detection signal is converted into an optical signal by the edge detection circuit 1m. Since it is converted into an optical detection signal by the E / O converter 1n after being converted into an edge detection signal of about 5%, power consumption in the E / O converter 1n can be greatly reduced.

  That is, as shown by the waveform in FIG. 3, the detection signal has a duty ratio of approximately 50%, that is, the time ratio between the ON state and the OFF state is approximately equal, but the edge detection signal has a duty ratio of approximately 5%, The time ratio between the state and the OFF state is greatly different (in FIG. 3, the ON state time is extremely shorter than the OFF state time). Therefore, by providing the edge detection circuit 1m, it is possible to make the time of the light emitting state in the E / O converter 1n extremely shorter than the time of the non-light emitting state, and thus the power consumption of the E / O converter 1n. Can be greatly reduced.

  By reducing the power consumption of the E / O converter 1n caused by the edge detection circuit 1m, it is possible to significantly reduce the power consumption of the water level meter 1 as a whole. In this water level measurement system, even when the electric double layer capacitor 1c having a smaller storage capacity than that of a normal secondary battery is used as the storage means, the power supply interval is set to a relatively long interval of 3 hours. Therefore, the probability that the induced lightning enters the feeder line 3, that is, the failure probability of the water level gauge 1 due to the induced lightning is reduced.

In addition, this invention is not limited to embodiment mentioned above, For example, the following modifications can be considered.
(1) Although the connection switching function is configured by the resistor 1k and the photocouplers 1i and 1j in the above embodiment, the configuration of the connection switching function is not limited to this. For example, the voltage of the induced lightning is reduced to about several tens of volts by the abnormal voltage surge function provided by the lightning arrester 1e, the resistors 1f and 1g and the diode 1h provided in the previous stage of the connection switching function. Other switch elements having a withstand voltage of about several tens of volts may be used.

(2) In the above embodiment, the power storage means is configured by one electric double layer capacitor 1c. However, the power storage means may be configured by a plurality of electric double layer capacitors connected in parallel or / and in series.

It is a system configuration figure showing the whole water level measurement system composition concerning one embodiment of the present invention. It is a circuit diagram which shows the principal part detailed structure of the electric power feeding system of the water level indicator 1 of the water level measuring system concerning one Embodiment of this invention, and the electric power feeder 2. FIG. It is a block diagram which shows the signal transmission structure of the water level measurement system concerning one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water level meter, 1a ... Protection circuit (induction lightning protection means), 1b ... Regulator, 1c ... Electric double layer capacitor, 1d ... Water level sensor, 1m ... Edge detection circuit, 1n ... E / O Converter, 2 ... Power supply device, 2a ... Power supply device, 2b ... Switch, 2c ... Relay drive circuit, 2d ... Timer, 3 ... Power supply line, 4 ... Transmission optical fiber, 5 ... Data Receiver circuit, 5a ... O / E converter, 5b ... 1/2 divider, 6 ... data processing device

Claims (3)

A water level meter provided in the river, which outputs water level measurement data measured based on the power stored in the predetermined power storage means to the outside as an optical signal, and includes an induced lightning protection means,
A power supply device that is provided apart from the water level meter and supplies power to the water level meter via a predetermined power supply line;
One end is connected to the water level gauge, a transmission optical fiber for transmitting the optical signal,
A data processing device connected to the other end of the transmission optical fiber, receiving water level measurement data by receiving the optical signal, and performing a predetermined process on the water level measurement data;
The induced lightning protection means detects power feeding from the power feeding device to the water level gauge, and when not in a power feeding state, opens the power feeding line.   The water level measurement system according to claim 1, wherein the power storage hand is an electric double layer capacitor.   The water level measurement system according to claim 1 or 2, wherein the induced lightning protection means switches between an open state / connected state of the feeder line by using a semiconductor switch.

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