JP4127895B2 - Surge current detection display device and sensitivity setting method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surge current detection display device used as a lightning strike indicator or the like.
[0002]
[Prior art]
When lightning strikes a transmission line or steel tower that transmits power generated at a power plant, and the lion string flashes, an arc remains on the surface or damage occurs due to the lightning strike current. Performance may be impaired. Therefore, a lightning strike indicator has been developed in order to reliably and clearly find such an accident point caused by a lightning strike. This lightning strike indicator is generally used by being attached to a power transmission tower, and when a surge current flows through the tower due to a lightning strike, this surge current is detected and the display unit operates.
[0003]
The operation status of such a lightning strike indicator is greatly influenced by the size of the tower base at the installation location. Therefore, it is necessary to adjust the sensitivity for each mounting location. Conventionally, products adjusted to a fixed sensitivity have been provided to the market. In addition, adjustment of the sensitivity using the volume is conceivable, but it cannot be used due to various problems.
[0004]
[Problems to be solved by the invention]
That is, in the sensitivity adjustment using the volume, the accuracy of the volume is not good, and there is a problem that accurate sensitivity adjustment cannot be performed even if the scale is swung around the knob. The lightning indicator is used outdoors for a long time, but the volume is not reliable as a part for a long time, so it cannot actually be used. In addition, if the volume knob is led out of the case of the device, the tree branches that have been blown by the wind may hit the knob, which may deviate from the adjusted position and the set sensitivity can be accurately set. There were also problems that could not be maintained.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides the following surge current detection display device. That is, a detection unit that detects generation of a surge current as a surge voltage, a display unit that displays detection of surge voltage, and a drive circuit and a drive unit that operate the display unit when a surge voltage is detected by the detection unit A plurality of fixed resistors having different values as means for adjusting the sensitivity of how much the surge voltage is detected when the display circuit is operated. A surge current detection display device having a fixed resistance changeover switch.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a surge current detection display device according to the present invention will be described in detail with reference to the accompanying drawings. The embodiment is a case where the surge current detection display device of the present invention is used as a lightning strike indicator. Therefore, it is hereinafter referred to as a lightning strike indicator.
[0007]
2A and 2B are diagrams showing a lightning strike indicator according to an embodiment of the present invention, in which FIG. 2A is a front view with the front cover removed, and FIG. 2B is a partially cutout bottom plate of the case. It is a bottom view. FIG. 3 is a partially cutaway front view when the lightning strike indicator of FIG. 2 operates. In these drawings, reference numeral 11 denotes a case, which is attached to a tower leg about 1 m to 1.5 m below the lowermost arm of the power transmission tower, for example. The case 11 is openable and closable with the bottom plate 12 having one side end 12a as a fulcrum. However, the bottom plate 12 is normally temporarily fixed in a closed state as shown in FIG. 2 by a leaf spring member (elastic member) 13. A search coil 21 that detects the generation of a surge current as a surge voltage is accommodated in the lower back surface of the case 11. The case 11 houses a drive circuit and drive unit 31 and a display cloth 41 as a display unit. The display cloth 41 as a display unit has, for example, a red band shape, and the upper end is fixed in the case 11. On the other hand, a weight 42 is attached to the lower end of the display cloth 41, and the display cloth 41 is wound around the weight 42 and accommodated in the case 11 on the bottom plate 12.
[0008]
The drive circuit and drive unit 31 includes a circuit unit 32 configured on a printed circuit board, a plunger 33 as a drive unit for driving the display unit, and a rotary switch 34 for sensitivity adjustment. When the plunger 33 operates, the shaft 33a is provided so as to push the bottom plate 12 of the case 11 downward from the inside. The solenoid 33 b of the plunger 33 is electrically connected to the output part of the circuit part 32. On the other hand, a search coil 21 serving as the detection unit is connected to the input unit of the circuit unit 32. Further, a sensitivity adjusting rotary switch 34 electrically connected to a predetermined portion of the circuit portion 32 is attached to an upper portion of the case 11, and a knob 34 a with a silicon rubber cap of the rotary switch 34 is provided in the case 11. The upper surface is led out.
[0009]
In the lightning strike indicator configured as described above, when a surge current flows through a steel tower to which the lightning strike indicator is attached, a surge voltage is generated in the search coil 21 due to electromagnetic induction. Then, the plunger 33 of the drive circuit and drive unit 31 is operated by the action of the circuit unit 32 of the drive circuit and drive unit 31, and the bottom plate 12 of the case 11 is pushed downward from the inside by the shaft 33a of the plunger 33. The temporary fixing by the leaf spring member 13 is released, and the bottom plate 12 of the case 11 is opened downward as shown in FIG. Then, the display cloth 41 with the weight 42 attached to the lower end hangs down below the case 11 as shown in FIG. 3, and the generation of the surge current and the detection of the surge voltage are displayed.
[0010]
Therefore, the inspection operator can confirm that a surge current is generated in the steel tower by seeing the hanging of the display cloth 41, and performs the inspection operation. The lightning strike indicator can be prepared for the next surge current by winding the hanging display cloth 41 around the weight 42 and accommodating it again in the case 11 and closing the bottom plate 12, and can be used repeatedly.
[0011]
FIG. 1 is a detailed electric circuit diagram of the driving circuit and the driving unit 31. In this figure, reference numeral 35 denotes a rectifier circuit, which is configured by bridge-connecting four diodes D1 to D4. A search coil 21 as a detection unit is connected to the AC input units a and b of the rectifier circuit 35. A high voltage limiting varistor B is connected between the AC input parts a and b. Of the DC output units c and d of the rectifier circuit 35, the DC output unit c is grounded. On the other hand, the DC output unit d is connected to the sensitivity adjustment circuit 36.
[0012]
The sensitivity adjustment circuit 36 includes a rotary switch 34 in which one movable terminal connected to the DC output unit d of the rectifier circuit 35 is switched and connected to six fixed terminals, and one end connected to each fixed terminal of the rotary switch 34. The fixed resistors R1 to R6 are different in value, and the other ends of the fixed resistors R1 to R6 are commonly connected. The other end common connection portion of the fixed resistors R1 to R6 is connected to the switching circuit 37.
[0013]
The switching circuit 37 is connected between the other end common connection portion of the fixed resistors R1 to R6 of the sensitivity adjustment circuit 36 and the ground, and includes a capacitor C1 constituting an integrating circuit with any of the fixed resistors R1 to R6, and this A resistor R7 having one end connected to one end of the capacitor C1 on the fixed resistors R1 to R6 side, a constant voltage Zener diode Z1 connected between the other end of the resistor R7 and the ground, and the Zener diode Z1 in parallel. And a thyristor SCR as a switching element with the cathode of the Zener diode Z1 connected to the gate and the cathode grounded.
[0014]
And the solenoid 33b of the plunger 33 is connected in series with the anode of this thyristor SCR.
[0015]
A power supply circuit 38 has a lithium battery E whose negative electrode is grounded, and a capacitor C2 connected in parallel to the lithium battery E via a diode D5 and a high resistance R9. The charging voltage of the capacitor C2 is the solenoid 33b. Is supplied as a power source.
[0016]
In the drive circuit and drive unit 31 configured as described above, when a surge voltage is detected by the search coil 21, the voltage is rectified by the rectifier circuit 35. Then, the rectified voltage is integrated by the capacitor C1 of the switching circuit 37 via any one of the fixed resistors R1 to R6 of the sensitivity adjustment circuit 36. When this integrated voltage becomes a predetermined voltage, the thyristor SCR of the switching circuit 37 is turned on, and a current flows through the thyristor SCR to the solenoid 33b, so that the plunger 33 operates and the display unit operates.
[0017]
The solenoid 33b and the thyristor SCR of the switching circuit 37 are supplied with power from the capacitor C2 of the power circuit 38. Therefore, when the capacitor C2 finishes discharging, the thyristor SCR is turned off, the current of the solenoid 33b is stopped, and the operation of the plunger 33 is finished. The capacitor C2 is then charged from the lithium battery E via the diode D5 and the high resistance R9 to prepare for the next operation.
[0018]
In the operation as described above, if a fixed resistor having a large resistance value is selected from the fixed resistors R1 to R6 by the rotary switch 34 of the sensitivity adjustment circuit 36, the capacitor C1 is detected unless a large surge voltage is detected by the search coil 21. The integrated voltage due to is not a predetermined voltage (the voltage at which the thyristor SCR is turned on and the display unit operates as a result), and the sensitivity of the lightning strike indicator is reduced. On the other hand, when a fixed resistor having a small resistance value among the fixed resistors R1 to R6 is selected by the rotary switch 34 of the sensitivity adjustment circuit 36, even if a small surge voltage is detected by the search coil 21, the integrated voltage by the capacitor C1 becomes a predetermined voltage. And the sensitivity of this lightning indicator will be good. Thus, in this lightning strike indicator, the sensitivity is adjusted according to the value of the fixed resistance selected by the sensitivity adjustment circuit 36. The fixed resistors R1 to R6 are set to six different resistance values. Therefore, according to this lightning strike indicator, the sensitivity can be adjusted to 6 levels by selecting any one of the fixed resistors R1 to R6 with the rotary switch 34 of the sensitivity adjustment circuit 36.
[0019]
According to this sensitivity adjustment method, since a highly accurate fixed resistor is used, sensitivity adjustment can be performed accurately. In the case of a fixed resistor and a switch (rotary switch), there is no problem even in long-term use, and highly reliable sensitivity adjustment is possible over a long period of time. Furthermore, in the case of a rotary switch, the knob is led out of the case, and the switch does not switch even if a tree branch or the like that has been blown by the wind hits the knob, so that the set sensitivity can be accurately maintained. .
[0020]
Furthermore, according to the sensitivity adjustment method described above, the sensitivity can be adjusted accurately and clearly, for example, in six stages. Therefore, the types of steel towers are classified into, for example, six kinds based on the transmission voltage and the size of the legs. By making the type of the switch correspond to the switch position of the rotary switch, it is possible to easily set the sensitivity accurately on the spot according to the type of the tower. For example, switch position 1 for transmission voltage 11-33 kV, leg size 122φ-191φ, switch position 2 for transmission voltage 11-33 kV, leg size-96φ, transmission voltage 66-77 kV, for leg material Switch position 3 for size 165φ to 191φ, switch position 4 for size 96φ to 140φ for leg, switch position 4 for size 96 to 140φ for leg, switch position 5 for size 96 to 165φ for leg voltage By making the transmission voltage 220 kV and the leg size ˜165φ correspond to the switch position 6 or the like, the sensitivity can be set easily and accurately without being confused at the site.
[0021]
The above embodiment is a case where the surge current detection display device of the present invention is used for a lightning strike indicator of a power transmission tower. However, the surge current detection display device of the present invention similarly applies a surge current to other equipment. Detection display is possible. Needless to say, the mechanical configuration and the electrical configuration can be variously modified except for the feature points. Furthermore, the number of sensitivity adjustment steps is not limited to six, but about six steps are not rough and not fine, and are the optimum number of steps.
[0022]
【The invention's effect】
As described above, according to the surge current detection display device of the present invention, it is possible to adjust the sensitivity easily, accurately, clearly, and with high reliability over a long period of time.
[Brief description of the drawings]
FIG. 1 is a detailed electric circuit diagram of a drive circuit and a drive unit in an embodiment of the present invention.
FIGS. 2A and 2B are a front view and a bottom view showing a lightning strike indicator as an embodiment of the present invention. FIGS.
3 is a front view showing a state during operation of the lightning strike indicator of FIG. 2. FIG.
[Explanation of symbols]
21 Search coil 31 Drive circuit and drive unit 36 Sensitivity adjustment circuit 34 Rotary switches R1 to R6 Fixed resistance

Claims (3)

A detection unit (21) for detecting the generation of surge current as a surge voltage, a display unit (41) for displaying detection of surge voltage, and a display unit (41) when the detection unit (21) detects a surge voltage. A surge current detection display device comprising a drive circuit and a drive unit (31) for operating
The drive circuit and the drive unit (31) have a plurality of fixed resistors (different values) as means for adjusting the sensitivity of operating the display unit (41) when a surge voltage is detected. R1, R2,...) And a fixed resistance changeover switch (34),
The drive circuit and drive unit (31)
A rectifier circuit (35) for rectifying the surge voltage detected by the detector (21);
A sensitivity adjustment circuit (36) connected to the output of the rectifier circuit (35) and configured to switch a plurality of fixed resistors (R1, R2,...) Having different values by a switch (34);
A switching circuit (37) connected to the output of the sensitivity adjustment circuit (36), integrating the input voltage and operating the switching element (SCR) when the integrated voltage reaches a predetermined voltage;
A drive unit (31) that operates the display unit (41) when the switching element (SCR) of the switching circuit (37) operates,
The sensitivity adjustment circuit (36) has a rotary switch (34) in which one movable terminal connected to the rectifier circuit (35) is switched and connected to a fixed terminal, and one end of each fixed terminal of the rotary switch (34). The other ends of the fixed resistors (R1, R2,...) Are connected in common and the other end common connection is connected to the switching circuit (37). And
The switching circuit (37)
Capacitors that are connected between the common connection of the other ends of the fixed resistors (R1, R2,...) Of the sensitivity adjustment circuit (36) and the ground and constitute an integrating circuit with any of these fixed resistors (R1, R2,...). (C1),
A resistor (R7) having one end connected to one end of the capacitor (C1) on the fixed resistor (R1, R2,...) Side;
A constant voltage Zener diode (Z1) connected between the other end of the resistor (R7) and the ground;
(R8) connected in parallel with the Zener diode (Z1);
The cathode of the Zener diode (Z1) is connected to the gate, the thyristor (SCR) as a switching element whose cathode is grounded, Bei give a,
The type of tower on which the surge current detection display device is installed is classified into a predetermined type from the transmission voltage and the size of the leg,
The surge current detection display device is characterized in that the sensitivity is set according to the type of the tower by associating the type of the tower with the switch position of the fixed resistance changeover switch ( 34 ). Current detection display device. In the surge current detection display device according to claim 1,
When the display cloth with the weight attached is accommodated in the case (11), and the bottom plate of the case (11) is opened by the operation of the drive section (31), the display cloth is attached to the display section (41). A surge current detection display device, characterized in that the detection of surge voltage is displayed below the case (11). A method of installing a surge current detection display device and setting its sensitivity,
The surge current detection display device,
A detection unit (21) for detecting the generation of surge current as a surge voltage, a display unit (41) for displaying detection of surge voltage, and a display unit (41) when the detection unit (21) detects a surge voltage. A surge current detection display device comprising a drive circuit and a drive unit (31) for operating
The drive circuit and the drive unit (31) have a plurality of fixed resistors (different values) as means for adjusting the sensitivity of operating the display unit (41) when a surge voltage is detected. R1, R2,...) And a fixed resistance changeover switch (34),
The drive circuit and drive unit (31)
A rectifier circuit (35) for rectifying the surge voltage detected by the detector (21);
A sensitivity adjustment circuit (36) connected to the output of the rectifier circuit (35) and configured to switch a plurality of fixed resistors (R1, R2,...) Having different values by a switch (34);
A switching circuit (37) connected to the output of the sensitivity adjustment circuit (36), integrating the input voltage and operating the switching element (SCR) when the integrated voltage reaches a predetermined voltage;
A drive unit (31) that operates the display unit (41) when the switching element (SCR) of the switching circuit (37) operates,
The sensitivity adjustment circuit (36) has a rotary switch (34) in which one movable terminal connected to the rectifier circuit (35) is switched and connected to a fixed terminal, and one end of each fixed terminal of the rotary switch (34). The other ends of the fixed resistors (R1, R2,...) Are connected in common and the other end common connection is connected to the switching circuit (37). And
The switching circuit (37)
Capacitors that are connected between the common connection of the other ends of the fixed resistors (R1, R2,...) Of the sensitivity adjustment circuit (36) and the ground and constitute an integrating circuit with any of these fixed resistors (R1, R2,...). (C1),
A resistor (R7) having one end connected to one end of the capacitor (C1) on the fixed resistor (R1, R2,...) Side;
A constant voltage Zener diode (Z1) connected between the other end of the resistor (R7) and the ground;
(R8) connected in parallel with the Zener diode (Z1);
A thyristor (SCR) as a switching element having a cathode connected to the gate of the Zener diode (Z1) and a grounded cathode;
Classifying the type of steel tower on which the surge current detection display device is installed is classified into a predetermined type from the transmission voltage and the size of the legs,
Surge current detection display characterized in that sensitivity is set according to the type of tower by associating the type of tower with the switch position of the fixed resistance changeover switch (34) of the surge current detection display device. Device sensitivity setting method.

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