JPH0535339Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) The present invention relates to a flash fault indicator suitable for notifying that a flash current has flowed through a flash fault detection target such as a power transmission tower. .

(Prior Art) Conventionally, flashover indicators have been designed to detect induced voltage by a detection coil placed in a magnetic field due to flashover current, explode gunpowder in response to this detection, and cause the explosion to occur. There is one that has a hanging flash indicator to alert you to a flash flash.

In the case of a flash flash indicator that hangs down to notify the presence or absence of a flash flash, once the gunpowder is exploded and the flash flash indicator hangs down, it cannot be used again. It is necessary to replace and reset the signs one by one, and since gunpowder has a limited service life, it is necessary to periodically replace it with new gunpowder. For this reason, there is the problem that each time a person has to climb a high steel tower, it takes a lot of money and effort, and the gunpowder may not explode due to moisture, so there is a problem that it lacks reliability.

Therefore, in recent years, instead of exploding gunpowder and causing flashlight signs to hang down, electro-fired signs, which change color due to an electrochemical reaction when an electric current is supplied, have been introduced.
Chromic display (hereinafter referred to as ECD display)
It is proposed to use

In this one, in response to the detection of an induced voltage,
A coloring current supply means for supplying a coloring current for coloring the ECD display body is activated, and when the voltage applied to the ECD display body reaches a certain voltage, the coloring current supply means is configured to stop operating. Once the ECD display is colored, the color density remains constant, so patrollers can
By visually checking whether the ECD display is colored or not, it is possible to confirm the presence or absence of flash flash.

(Problem that the invention attempts to solve) However, the flash fault indicator that uses the ECD display to detect the presence or absence of flash faults detects the flash fault current flowing through the tower by electromagnetic induction, and the detection coil The structure is such that the coloring current supply means is driven to start coloring when the induced voltage induced in the tower exceeds a certain voltage. Branch currents from the overhead ground wires of adjacent steel towers and flashfault currents (hereinafter referred to as lightning currents, including direct lightning currents, branch currents, and flashflash currents) flow as follow-on currents related to the deterioration of the insulators of the towers. However, with conventional flash fault indicators, coloring starts when the current value of lightning current, including direct lightning current, branch current, and flash fault current, exceeds a predetermined value. There is a problem in that it is not possible to distinguish between related follow-on currents such as flash current, branch current, and direct lightning current.

In addition, in order to prevent over-coloring of the ECD display, the conventional coloring current supply means supplies the coloring current when the voltage generated across the ECD display reaches a certain value after the coloring current supply means starts. It is configured to stop.

However, as shown in Figure 6, when the temperature of the ECD display is low, the voltage generated across the ECD display becomes saturated in a short time in response to the injection of a constant coloring current, and as the temperature rises, the voltage generated across the ECD display becomes saturated. Tsute
It has voltage-temperature characteristics such that the time it takes for the voltage generated at both ends of the ECD display to reach saturation is extended, and when the coloring stop voltage V _c for stopping the coloring current supply is determined, for example, the temperature T ₁ , T ₂ , T ₃
When T ₁ > T ₂ > T ₃ , the energization period from starting the supply of the coloring current to stopping the supply of the coloring current varies as t ₁ > t ₂ > t ₃ . The coloring density of the ECD display is proportional to the amount of charge injected, so in the case of conventional systems that supply coloring current as a constant current, the coloring density of the ECD display differs based on variations in the energization period due to temperature changes. There is a problem.

In addition, in order to solve the problem that the coloring density of the ECD display body differs based on variations in the energization period due to temperature changes, as shown in Fig. 7, the environmental temperature is detected using a thermistor, and the coloring stop voltage V _c
automatically changes based on temperature changes, ECD
A temperature-compensated type has also been developed in which the period during which electricity is applied to the display body is kept constant. This figure 7 is
In order to maintain the energization period at a constant value _Tc1 in the range of _T1 to _T2 , the coloring stop voltage _Vc is varied in the range of _Vc1 to _Vc2 . However, the temperature compensated type has a limited range of temperature compensation, for example,
Even if you try to compensate for the temperature up to T ₃ , which is lower than T ₂ , the generated voltage will saturate in a short time, so the coloring stop voltage will decrease before the generated voltage reaches saturation.
When V _c is set, the energization period has to be shortened, for example, as shown by t _c2 , and there is a problem in that the coloring density of the ECD display becomes thinner.

Therefore, the present invention extracts the flash fault current component related to the deterioration of the insulator of the steel tower separately from other lightning currents, makes it possible to display flash faults based on the flash fault current component, and makes it possible to display flash faults based on the flash fault current components. It is an object of the present invention to provide a flash flash indicator that can suppress variations in coloring density caused by the above.

Structure of the Device (Means for Solving Problems) In order to achieve the above-mentioned purpose, the present invention detects a flash current by extracting the flash current component from the lightning current flowing through the object to be detected. fault current detection means; coloring current supply means for supplying a coloring current to the electrochromic display for causing a color change to the electrochromic display in response to the detection of the flashover current component; a decoloring current supply means for supplying a decoloring current to the electrochromic display body to return the electrochromic display body to the state before the color change; and a command for providing a command signal to operate the decolorizing current supply means. The flash current detection means is provided with a filter means for passing the flash current component, and the coloring current supply means receives an output from the flash current detection means and provides a constant current. A timer means is provided for supplying the coloring current to the electrochromic display for a predetermined period of time.

(Function) According to this, when lightning current flows through a steel tower,
The flash current detection means extracts a flash current component related to deterioration of the insulator. A timer means is driven based on this flash current component, and a constant current is supplied to the ECD display as a coloring current. E.C.D.
The display body undergoes a color change due to the injection of this constant current. Then, after a certain period of time has elapsed, the supply of the constant current is stopped by the timer means, and the ECD display maintains the color after the color change.

(Example) Hereinafter, an example of the flashover indicator according to the present invention will be described based on the drawings.

FIG. 1 is a circuit diagram of the main parts of a flashover indicator according to the present invention. In FIG. 1, 1 is a flashover current detection means, 2 is a coloring current supply means, and 3 is a decolorization current supply means. . The flash fault current detection means 1 is roughly composed of a detection coil device 4, a protection circuit 5, an integration circuit 6, an RC integration circuit 7, a low-pass filter 8, and a rectification circuit 9. As the detection coil device 4, a normal small transformer for power supply having the appearance shown in FIG. 2 is used here. This small transformer for power supply was used as the detection coil device 4 because it is suitable only for commercial frequencies of 50 Hz or 60 Hz, and is manufactured with low loss for that commercial frequency, making it suitable for detecting flash current components. This is because it is preferable.

This detection coil device 4 is attached to a steel tower leg 10 with bolts 13 via an insulating case 11 and a stopper 12, as shown in FIG. The coil 14 of the detection coil device 4 is arranged so as to interlink with the magnetic flux H generated by the lightning current A flowing through the tower leg 10. FIG. 4 shows the relationship between the lightning current A flowing through the coil 14 and the tower leg 10 and the magnetic flux H, where the magnetic flux H is generated in a direction perpendicular to the plane of the paper. Note that 15 is an iron core. When lightning current A flows through the tower leg 10 from top to bottom, a magnetic flux H is generated surrounding the tower leg 10 as shown in FIG. The detection coil device 4 may be installed by arranging the detection coil device 4 so as to be interlinked with the
The present invention is not limited to the embodiments shown in FIGS. 3 and 4.

A detection current generated in the detection coil device 4 based on the lightning current A is input to the protection circuit 5. This protection circuit 5 is intended to prevent subsequent electronic circuits from being destroyed by a detection current containing a very steep large current component based on lightning current.
diodes and surge component absorption materials are used. The detected current is input to the integrating circuit 6 after its steep large current component is removed. This integrating circuit 6 uses an operational amplifier with a high cutoff frequency of 40 Hz and a gain of 20 dB. The integrating circuit 6 has a function of roughly extracting the flash current component.

The detected current based on the lightning current is inputted to the RC integrating circuit 7 after the flash current component is roughly extracted by the integrating circuit 6 . RC integration circuit 7 is 1.8msec
It has a time constant of Even if the detection current based on the lightning current passes through the protection circuit 5 and the integration circuit 6, there is still a fairly high voltage component and a high frequency component due to ringing due to stray capacitance during the first short period of time, so this RC integration circuit 7 removes high frequency components and high voltage components based on ringing due to stray capacitance. If the time constant of the RC integrator circuit 7 is set to a large value, the effect of removing unnecessary components will increase, but the flash current component that should be detected will be cut out, and the detection sensitivity will become dull, so it will not be possible to remove the flash current. One cycle of the short circuit current component (60Hz, approx.
The time constant is set to about 1/10 of 17 msec), but the time constant is not limited to this. If the flash current component persists for a long time, the time constant may be set large, and in the opposite case, the time constant may be set small. Good too.

After passing through the RC integration circuit 7, the detection current is input to a Butterworth type low-pass filter 8. This low-pass filter 8 uses an operational amplifier with a high cutoff frequency of 60 Hz, and has a function of extracting only the flash current component. The output of this low-pass filter 8 is input to a rectifier circuit 9. This rectifier circuit 9 uses a combination of a diode and an operational amplifier having a gain, and may be either half-wave rectifier or full-wave rectifier.

The coloring current supply means 2 includes a coloring timer start signal generation circuit 17, a coloring timer circuit 18, and a constant current driving transistor 19. The erasing current supply means 3 includes an erasing command means 20, an erasing timer start signal generation circuit 21, and an erasing timer circuit 22.
and a switch switching transistor 23. 24 is an ECD display body. ECD display body 2
Switches 25 and 26 are connected to both ends of the switch 4, and a relay 27 is provided on the collector side of the switch switching transistor 23, and when the relay 27 is energized, the switch 25 switches from the side connected to the terminal 25a. At the same time as the switch 26 is switched from the connection side to the terminal 26a to the connection side to the terminal 26b, coloring and decoloring are switched. In addition, 28
is a diode connected in parallel to the relay 27, and is used to prevent abnormal voltage from occurring in the excitation coil of the relay 27.

The coloring current supply means 2 and the color erasing current supply means 3 are reset when the power is turned on, and a reset signal generating circuit 29 is connected to the coloring current supply means 2 and the color erasing current supply means 3 when the power is turned on. . 30
is its power supply circuit, and this power supply circuit 30 is composed of a solar battery 31 and a secondary battery 32, and has a structure in which the solar battery 31 floats and charges the secondary battery 32, and 33 is a backflow prevention diode. It is.

The power-on reset signal generation circuit 29 generates a reset signal when the power supply circuit 30 is turned on, and the coloring timer start signal generation circuit 17 and the coloring timer circuit 1
8. Output to the erasing timer circuit 22.
The colored timer start signal generation circuit 17 is composed of a D flip-flop, and when the output of its Q terminal becomes low level by the reset signal and the rising edge of the output from the rectifier circuit 9 is input to its CP terminal, The output of the Q terminal is initially set to a high level. Colored timer circuit 18
When the reset signal is input, the timekeeping contents are cleared even if the timekeeping operation is in progress, and the terminal A is
Until the timer start signal is input from , the timer does not measure time and enters a timer standby state. When the reset signal is inputted to the decoloring timer circuit 22, the timekeeping contents are cleared even if the timer is in operation, and the timer circuit 22 does not perform timekeeping until the timer start signal is inputted from the terminal S, and enters the timekeeping standby state. Become.

Next, the operation of this flashover indicator will be explained with the detailed circuit configuration.

When the flash current component converted to DC is applied to the coloring timer start signal generation circuit 17 and the voltage at the CP terminal of the coloring timer start signal generation circuit 17 rises to a predetermined voltage or higher, the terminal Q becomes high level and the coloring starts. A timer start signal is output. The coloring timer circuit 18 is driven by the coloring timer start signal and starts operating, and the product of the resistance value R ₁ ′ of the resistor R ₁ and the capacitance value C ₁ ′ of the capacitor C ₁ is R ₁ ′ × C ₁ ′.
During the time determined by the time constant of , the output of the Q terminal becomes high level. When the output of the Q terminal becomes high level, ECD is connected through resistor _R3 .
The constant current drive transistor 19 for driving the display body 24 is turned on, and a constant current is supplied from the power supply circuit 30 to the ECD display body 24 through the variable resistor R ₄ for adjusting the constant current and the diode 34 for backflow prevention.
The ECD display body 24 is colored by this. Note that a variable resistor is used as the resistor _R1 , and in order to adjust the coloring density, the driving time of the constant current drive transistor 19 can be changed by operating this variable resistor. It's getting old. In addition, the backflow prevention diode 34 is connected to the ECD display 24 after the colored current supply is stopped.
The voltage generated across the ECD display 2
It has a function of preventing the charge of No. 4 from flowing back into the coloring timer circuit 18 through the base and emitter.

According to this coloring current supply means 2, since coloring is started based on the flashover current component itself, it is possible to distinguish between the flashover current related to the deterioration of the insulator and other lightning currents. Furthermore, since the coloring current is supplied at a constant current for a predetermined period of time, it is possible to suppress variations in coloring density due to variations in the energization period.

Next, the case of color erasure will be explained.

When a flash current component is applied and the output of the Q terminal of the colored timer start signal generation circuit 17 becomes high level, the power supply transistor 35 is turned on via the resistor _R6 , and the power supply voltage is applied to the photoelectric converter 36. At the same time, the erasing timer start signal generating circuit 21 is reset. The color erasing timer start signal generating circuit 21 is constructed from a D flip-flop like the coloring timer start signal generating circuit 17. When the power supply voltage is supplied to the opto-electric converter 36, the opto-electric converter 36 can receive an optical signal as a decoloring command signal transmitted via the optical fiber 37.

After confirming that the ECD display 24 is colored, the patrolman operates a decoloring command signal operating means (not shown). Then, an optical signal as a color erasing command signal is received by the opto-electrical converter 36 via the optical fiber 37, converted into an electrical signal, and inputted to the S terminal of the color erasing timer start signal generation circuit 21. The erasing timer circuit 22 starts operating when the Q terminal of the erasing timer start signal generating circuit 21 becomes high level. The decoloring timer circuit 22
is the resistance value R ₂ ′ of resistor R ₂ and the capacitance value of capacitor C ₂
During the time determined by the time constant of the product R _{2 ′} × C _{2 ′ of C 2} ′, the output of the Q terminal becomes high level,
Its output is the switch switching transistor 23
is applied through resistor _R5 . The switch switching transistor 23 is driven while the output of its Q terminal is at a high level, the relay 27 is energized, and the switches 25 and 26 are switched. By this, from the power supply circuit 30 through the resistor _R7 ,
A decoloring current in the opposite direction to the coloring current is supplied to the ECD display 24, so that the ECD display 24 is decolored.
Note that the resistor _R7 functions as a decoloring current limiting resistor. Furthermore, when the Q terminal of the decoloring timer circuit 22 becomes high level, its output is connected to the diode 38.
The signal is input as a reset signal to the coloring timer start signal generation circuit 17, and the coloring timer start signal generation circuit 17 is interlocked and enters a standby state. Before the color is erased, coloring starts based on the next flash current, and the ECD display 2
This is to prevent 4 from being destroyed.

Effects of the Invention As explained above, the flash indicator according to the invention has a configuration in which the flash current component is extracted from the detected current based on the lightning current, and the electrochromic display is colored based on the flash current component. As a result, it is possible to reliably indicate the occurrence of a flashover current related to the deterioration of the insulator, and its practical value is dramatically improved when installed on a power transmission tower.

In addition, since the coloring is carried out using a constant current for a certain period of time, it is possible to suppress variations in the coloring density due to variations in the energization period caused by temperature changes, and this improves usability, especially in low-temperature areas, making it ideal for buildings built in mountainous areas. It has the effect of being able to withstand practical use even when installed on a power transmission tower.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the main parts of the flashover indicator according to the present invention, Figure 2 is an external view of the detection coil device according to the present invention, and Figures 3 and 4 are the steel tower of the detection coil device according to the present invention. A diagram showing how it is attached to the leg, Figure 5 shows how magnetic flux is generated when lightning current flows through the tower leg, and Figures 6 and 7 explain the problems with conventional flash fault indicators. This is a diagram for DESCRIPTION OF SYMBOLS 1... Flash fault current detection means, 2... Coloring current supply means, 3... Color erasing current supply means, 8... Low pass filter, 17... Coloring timer start signal generation circuit, 18... Coloring timer circuit, 19 ... Constant current drive transistor, 24 ... ECD display body.

Claims (1)

[Scope of Claim for Utility Model Registration] Flash current detection means for detecting a flash current component from a lightning current flowing through an object to be detected, and an electrochromic display in response to the detection of the flash current component. a coloring current supplying means for supplying a coloring current to the electrochromic display body for imparting a color change to the body; and a coloring current supply means for supplying a coloring current to the electrochromic display body that has undergone a color change, and a decoloring current for returning the electrochromic display body that has undergone a color change to the state before the color change. A decoloring current supply means for supplying an electro-chromic display, and a command signal applying means for giving a command signal to operate the decoloring current supply means, and the flashing current detecting means has a decoloring current component. filter means for passing through the coloring current, and the coloring current supplying means is provided with timer means for supplying a constant current as the coloring current to the electrochromic display for a predetermined period of time. contact indicator.