JPH0533506B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lightning arrester operation detection device for detecting that a lightning current or the like flows through a lightning arrester element of a lightning arrester provided on a power transmission/distribution line.

(Prior Art) Lightning arresters are sometimes provided on steel towers of power transmission and distribution lines in order to protect the power transmission and distribution lines in the event of lightning strikes. This lightning arrester has a built-in lightning arrester that acts as a conductor against steep voltages, and is configured to discharge lightning current toward the ground through the conductor. However, until now, there have been few operating detection devices that detect lightning strikes. There was nothing more than something that would ignite gunpowder and activate a display mechanism such as a drapery.

(Problem to be solved by the invention) However, with the above configuration, it is necessary for track maintenance workers to visit the site one by one to find out whether there is a lightning strike.
Confirmation work was extremely difficult given that the steel towers were located over long distances in mountainous areas. Moreover, the shelf life of gunpowder is 3~
Since the life is limited to about 5 years, periodic replacement work is required, and the maintenance work is extremely complicated. Furthermore, in an operation detection device using gunpowder, 1
Since it stops working after one time, even if the lightning arrester malfunctions due to a lightning strike and a follow-on current flows to the lightning arrester, the hanging cloth will only hang down during the lightning strike, so it is difficult to determine whether the lightning arrester is normal or not. Another drawback was that it was not possible to clearly distinguish between the two.

Therefore, an object of the present invention is to make it possible to intensively monitor the presence or absence of lightning strikes from a remote location, and to
It is an object of the present invention to provide an operation detection device for a lightning arrester insulator that can accurately determine the failure of a lightning arrester element.

[Structure of the Invention] (Means for Solving the Problems) The operation detection device for a lightning arrester according to the present invention includes a current transformer provided in the current-carrying conductor of the lightning arrester, and a secondary current of the current transformer connected to a rectifier circuit. The electric charge stored in the electric storage element is discharged at a constant current for a predetermined time by the control means in accordance with the detection signal from the voltage detection means, thereby causing the light emitting element to emit light. The optical signal from the receiver can be transmitted to the receiving side using an optical fiber.

(Function) When there is a lightning strike, lightning current flows through the current-carrying conductor, so
The storage element is charged by the current transformer. Then, when the terminal voltage of the power storage element reaches a predetermined voltage or higher, the voltage detection means outputs a detection signal, so that the control means discharges the charge of the power storage element at a constant current value for a predetermined period of time via the light emitting element. As a result, the light emitting element emits light at a constant intensity for a predetermined period of time, and the optical signal is sent through an optical fiber to the receiving side of, for example, a substation or track maintenance station, thereby confirming that there has been a lightning strike. The light emitting energy of the light emitting element is supplied by the storage element charged by the secondary current of the current transformer, so there is no need for a power source such as a battery, making maintenance work inconvenient. It can be operated repeatedly. Moreover, when a follow-on current flows due to failure or deterioration of the lightning protection element, the terminal voltage of the storage element is maintained at a predetermined voltage or higher, and the voltage detection means continues to output a detection signal, so the light emitting element also outputs an optical signal. This makes it possible to identify abnormalities in the lightning arrester element. In addition, since the light emitting element is caused to emit light by the charge stored in the electricity storage element, even if the lightning current attenuates instantly, the light will continue to emit light at a constant intensity for a predetermined period of time after a lightning strike. There is no risk of overlooking the optical signal on the receiving side, and no signal hold circuit is required to prevent this.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

First, in FIGS. 2 and 3 showing a part of a power transmission line, 1 is a steel tower, 2 is an arm thereof, and a power transmission line 4 is supported at the tip of the arm 2 via a suspension insulator 3. Reference numeral 5 denotes a lightning arrester in which a lightning arrester element (not shown) made of, for example, ZnO is provided, and this is attached to the suspension insulator 3 via a mounting bracket 6. 7 is an arc horn provided at the lower end of the suspension insulator 3. Reference numeral 8 denotes a current-carrying conductor that connects between the grounding electrode of the lightning protection element and the mounting bracket 6, through which lightning current flows during a lightning strike.As shown in FIG. A current transformer 10 is provided within the case 9. This current transformer 10 is constructed by applying a secondary winding 12 to an annular core 11 surrounding a current-carrying conductor 8.
1 is made of a material that saturates the magnetic flux at several tens of A and has excellent frequency characteristics so that it can equally detect follow-on currents of 10 to 500 A and lightning currents of 10 KA or more.

Now, FIG. 1 shows a lightning arrester 5 embodying the present invention.
1 shows the entire circuit of the operation detection device A. In this Figure 1, 13 is a diode bridge that constitutes a rectifier circuit, and the AC input side of this is a current transformer 1.
0 secondary winding 12, and the DC output side is connected via a diode 14 to a capacitor 15 corresponding to a power storage element. In addition, a load resistor 16, a surge absorbing element 17, and a capacitor 18 are connected in parallel to the AC input side of the diode bridge 13. They are provided to bypass the load resistor 16 so that an excessive current does not flow instantaneously. on the other hand,
A light emitting diode 19 as a light emitting element and a series circuit of transistors 20 and 21 connected in Darlington are provided at both ends of the capacitor 15.
The base of the transistor 20 is controlled by a drive circuit 22, and when the transistors 20 and 21 are turned on, the light emitting diode 19 emits light due to the charge stored in the capacitor 15. The optical signal emitted from the light emitting diode 19 is sent to the receiving side through the optical fiber 23.

Next, regarding the drive circuit 22, 24
is a constant voltage diode that functions as a voltage detection means, and is connected in series with a resistor 25 between the DC output terminals of the diode bridge 13, and the common connection point of both is connected to an NPN via a resistor 26.
It is connected to the base of a transistor 27 of the form. This transistor 27 is combined with a PNP type transistor 28 in a thyristor type.
The emitter of transistor 27 is connected to the base of transistor 20. transistor 2
The potential of the emitter of transistor 7, that is, the base of transistor 20, is made constant by a constant voltage diode 29, and a capacitor 31 is charged via a resistor 30 based on the potential. still,
A constant voltage diode 29, resistors 30, 32, and a capacitor 31 constitute a control means. The charging side terminal of the capacitor 31 is grounded via a resistor 32, and is connected to a resistor 33 and
It is connected to the base of an NPN type transistor 35 configured in a thyristor type together with a PNP type transistor 34.

The operation detection device A having the above configuration is provided for each lightning arrester 5, and is housed in a case 9 that covers the current transformer 10 with the optical fiber 23 led out. Each steel tower 1 is provided with each optical fiber 2 of each operation detection device A, as shown in FIG.
A multiplexer 36 is provided to combine the optical signals from 3, and from there the signals are sent via an optical fiber cable 37 to a central monitoring device installed at a substation or track maintenance station.

Next, the operation of this embodiment will be explained. When lightning strikes and the lightning arrester 5 is activated, a lightning current flows through the current-carrying conductor 8. As a result, a secondary current flows through the secondary winding 12 of the current transformer 10, and the diode bridge 1
3, and the capacitor 15 is charged. When the charging of the capacitor 15 progresses and the voltage between the terminals rises, when the voltage reaches a predetermined level, the voltage regulator diode 24 is turned on and the voltage at the common connection point between the voltage regulator diode 24 and the resistor 25 is raised, thereby detecting the voltage. Output a signal. As a result, the transistors 27, 20, and 21 are sequentially turned on, the light emitting diode 19 lights up, and a light signal is emitted. Although the lightning current rapidly attenuates, since sufficient charge is already stored in the capacitor 15, the light-emitting diode 19 is kept lit by the charge. At this time, since the base potential of the transistor 20 is made constant by the constant voltage diode 29, the current flowing through the light emitting diode 19 is kept constant, and the optical signal maintains a constant strength. If this state continues, the capacitor 31 of the drive circuit 22 will be gradually charged via the resistor 30, so initially,
The potential at the charging side terminal of the capacitor 31, that is, the base potential of the transistor 35, which has been maintained at the ground level via the resistor 32, rises, and the transistor 35 is turned on after a predetermined time has elapsed since the lightning strike. As a result, the transistor 34 is turned on, so the transistors 28, 27, 20, and 21 are turned off, and the light emitting diode 19 is turned off. Therefore, in this embodiment, when there is a lightning strike, the light emitting diode 19 emits light at a constant intensity for a predetermined period of time, regardless of the strength or duration of the lightning current. This optical signal is sent to the multiplexer 36 through the optical fiber 23, and is sent from each tower 1 through the optical fiber cable 37 to the central monitoring device of the substation or track maintenance station. Lightning strikes can be monitored intensively. In this case, the optical signal continues at a constant intensity for a predetermined period of time as described above, so even if the lightning current attenuates instantaneously, it is extremely easy to monitor the lightning strike situation and display and record data. The processing for this also becomes easier.

In addition, in the event that the lightning protection element of the lightning arrester 5 breaks down or deteriorates due to a lightning strike or due to factors over time, and a follow-on current flows through the lightning protection element, the follow-on current flowing through the current-carrying conductor 8 will cause current transformation. Secondary winding 12 of device 10
Since an alternating secondary current flows through the capacitor 15
is always in a charging state, and the constant voltage diode 24 is also always in an on state at that terminal voltage, so that the light emitting diode 19 lights up and an optical signal is sent to the central monitoring device. The optical signal in this case is different from that in the case of an electric shock and continues without being cut off within a predetermined period of time, so it can be clearly distinguished from the case of an electric shock and it is easy to detect abnormalities in the lightning arrester 5. You can know.

[Effects of the Invention] As described above, the present invention provides a current transformer in the current-carrying conductor of a lightning arrester, charges the secondary current of the current transformer to a power storage element through a rectifier circuit, and charges the power storage element of the power storage element. When the terminal voltage reaches a predetermined voltage or higher, the control means discharges the electric charge of the storage element through the light emitting element at a constant current for a predetermined period of time in response to a detection signal output from the voltage detection circuit. By sending an optical signal with a constant intensity for a predetermined period of time to the receiving side via an optical fiber, the operating status of the lightning arrester can be monitored centrally, and the secondary current of the current transformer is used as operating energy. It is maintenance-free, and overall maintenance work for power transmission and distribution lines is significantly reduced. Furthermore, since the light emitting element emits light using the charge stored in the storage element, even if the lightning current attenuates instantaneously, the optical signal can be output continuously at a constant intensity for a predetermined period of time, making it possible to avoid oversight. In addition, signal processing for monitoring, recording, etc. becomes easier. Furthermore, when a follow-up current flows due to an abnormality in the lightning arrester, an optical signal continues to be output, making it possible to clearly distinguish between a signal caused by a lightning strike and a signal due to an abnormality in the lightning arrester, so failure or deterioration of the lightning arrester can be accurately detected. This has the excellent effect of making it possible to make judgments based on

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a circuit diagram of an operation detection device, Fig. 2 is a perspective view showing a part of a power transmission line, and Fig. 3 is an enlarged perspective view showing a mounting part of a lightning arrester. , FIG. 4 is a perspective view showing a current-carrying conductor and a current transformer. In the drawing, 5 is a lightning arrester, 8 is a current-carrying conductor, 10 is a current transformer, 12 is a secondary winding, 15 is a capacitor (power storage element), 19 is a light emitting diode (light emitting element), 2
2 is a drive circuit, 23 is an optical fiber, and A is a lightning arrester operation detection device.

Claims (1)

[Claims] 1. A current transformer installed on a current-carrying conductor that conducts current flowing through the lightning arrester element of a lightning arrester, a rectifier circuit that rectifies the secondary current of this current transformer, a storage element that is charged by the output of this rectifier circuit, and voltage detection means that outputs a detection signal when the terminal voltage of the electricity storage element is equal to or higher than a predetermined voltage; and when the detection signal is given from the voltage detection means, the charge stored in the electricity storage element is discharged with a constant current for a predetermined time. 1. An operation detection device for a lightning arrester, comprising: a control means for causing a discharge current to flow through the control means; and a light emitting element that emits light when energized by a discharge current caused by the control means and sends an optical signal to a receiving side via an optical fiber.