JPH0417286A - Lightning detection and notification device - Google Patents

Abstract

PURPOSE:To extend the distance between a current detecting part and a reporting part by separating an electric current signal which is detected by one electric current detecting means into a surge current component and an accidental electric current component, rectifying the separated electric signal components, adding them, and converting them into an optical signal. CONSTITUTION:An electric current detected by one electric current detecting means CT and containing a surge electric current component and an accidental electric current component is separated by a separating means 8, and after the resulting two electric currents are rectified by rectifying means Wl,, W2, they are added by an adding means 41. The electric signal of the addition result is converted into an optical signal by a converting means LED and the optical signal is sent to a reporting means. That is, a surge electric current component and an accident electric current component are detected by one electric current detecting means CT and those are converted into an optical signal and sent to the reporting signal after they are processed by a prescribed treatment. Consequently, without being affected by an induction noize, the dis tance between the current detecting part and the reporting part can be extended.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention generally relates to a lightning detection and notification device, and more particularly to a lightning detection and notification device that detects the occurrence of a lightning strike and the occurrence of a failure of a lightning arrester, and remotely reports these. Regarding.

[Prior Art] In order to detect and notify the occurrence of a lightning strike on a power transmission line and a failure of a lightning arrester, a lightning detection and notification device has conventionally been provided on a power transmission line tower. In conventional devices, two current transformers (CTs) are used to detect each surge current and fault current flowing through the lightning arrester. In other words, a current transformer is used to detect the surge current (several kA to several tens of kA) that flows from the lightning arrester toward ground when a lightning strike occurs, and the fault current (several hundred A) that flows when the lightning arrester fails. A current transformer is provided for the purpose. By detecting the surge current, an electromagnetic counter was activated to report the number of surge current peaks, and gunpowder was ignited to display a flag to indicate the operation and failure of the lightning arrester. .

Therefore, the two current detection sections and the display section need to be connected by electric wires and therefore need to be arranged close to each other. In particular, the current detection section and display section are generally located in locations where induction noise is very likely to occur, such as on power transmission towers and substations, so the current detection section and display section are It was not possible to provide the display section at a distance of more than a predetermined distance.

In addition, as mentioned above, the difference between the values of surge current and fault current is very large, so two current transformers are required, one for surge current detection and one for fault current detection, which increases the cost of installing the device. It was increasing.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to increase the distance between the current detection section and the notification section in a lightning detection and notification device. Another object of the present invention is to detect surge currents and fault currents using a single current detection means in a lightning detection and notification device.

[Means for Solving the Problems] The lightning detection and notification device according to the invention of claim 1 includes a single current detection means for detecting a current including a surge current flowing into a lightning arrester due to a lightning strike and a fault current generated due to a failure of the lightning arrester. a first separating means for separating the detected current into a surge current component and a fault current component; and a rectifying means for rectifying each separated surge current component and fault current component, respectively;
summing means for summing the rectified currents; first converting means for converting the summed electrical signal into an optical signal; and a first converting means connected to receive the converted optical signal and responsive to the converted optical signal. and a notification means for notifying the occurrence of a lightning strike and a failure of a lightning arrester.

The lightning detection and notification device according to the invention of claim 2 comprises: a saturation type current transformer connected to receive a current including a surge current flowing into a lightning arrester due to a lightning strike and a fault current generated due to a failure of the lightning arrester; a first conversion means for converting an output current into an optical signal; and a notification means connected to receive the converted optical signal and for notifying the occurrence of a lightning strike or a failure of a lightning arrester in response to the converted optical signal. including. The saturation current level of a saturation type current transformer is set between the maximum level of surge current and the maximum level of fault level.

The notification means of the lightning detection and notification device according to the invention of claim 1 or 2 includes a second conversion means for converting the optical signal converted by the first conversion means into an electrical signal; a second separating means for separating the signal into a surge current component and a fault current component; a lightning strike determining means for determining the occurrence of a lightning strike in response to the separated surge current component;
A failure determining means for determining the occurrence of a failure in the lightning arrester in response to the separated fault current component, and a display means for displaying the occurrence of a lightning strike and the occurrence of a failure of the lightning arrester determined by the lightning strike determining means and the failure determining means. include.

[Operation] In the lightning detection and notification device according to the present invention, the current containing the surge current component and the fault current component detected by the single current detection means is separated by the first separation means. These two currents are rectified by a rectifier and then added by an adder. The added electrical signal is converted into an optical signal by the first conversion means, and the converted optical signal is sent to the notification means. In this way, surge current components and fault current components are detected by a single current detection means, and these are converted into light signals after predetermined processing and sent to the notification means, so they are not affected by induced noise. In addition, the distance between the current detection section and the notification section can be increased.

In the lightning detection and notification device according to the second aspect of the invention, surge current and fault current are detected by a single saturated current transformer. Since the saturation current level of the current transformer is set between the maximum level of the surge current and the maximum level of the fault current, the level of amplitude possible for converting and transmitting these two current signals into an optical signal is converted. Since the converted optical signal is sent to the notification means, the distance between the current detection section and the notification section can be increased.

[Embodiment of the Invention] FIG. 2 is a conceptual diagram showing an application example of the lightning detection 6 notification device according to the present invention. Referring to Figure 2, insulator 4 is attached to steel tower 6.
A power transmission line 5 is disposed via. A lightning arrester 1 is provided at the top of the steel tower 6. The current flowing through the lightning arrester 1 is detected by the current transformer CT, and the detected signal is given to the detection device 2. In the detection device 2, predetermined signal processing is performed on the signal component of the surge current caused by the occurrence of a lightning strike and the signal component of the fault current indicating the occurrence of a failure of the lightning arrester, among the detected signals. The processed signal is converted into an optical signal, and the optical signal is transmitted to the display device 3 provided at the bottom of the steel tower 6 via the optical fiber 9. On the display device 3, the occurrence of a lightning strike and the occurrence of a failure of a lightning arrester are displayed.

FIG. 1 is a circuit block diagram showing an embodiment of a lightning detection and notification device according to the present invention. The device shown in Figure 1 is
It is used as the detection device 2 shown in FIG. Referring to FIG. 1, this lightning detection and notification device includes a current transformer CT that detects the current I flowing through the lightning arrester, an input protection section 7 that performs input protection and sensitivity adjustment, and a current transformer CT that detects the current I flowing through the lightning arrester. A pulse transformer 8 that branches the signal into a surge current component and a fault current component, a fault detector 20 that detects the fault current component, a surge detector 30 that detects the surge current component, and a pulse transformer 8 that branches the signal into a surge current component and a fault current component; It includes an LED driving section 40 that drives a light emitting diode LED. Failure detection section 20 includes resistors R1 and R2, Zener diodes ZDI and ZD2, and rectifier W1. The surge detection section 30 includes a rectifier W2 and a resistor R4. The LED driving section 40 includes an adder 41, a resistor R3, a protection diode D1, and a light emitting diode LED.

FIG. 3 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 1. The operation will now be described with reference to FIGS. 1 and 3.

The signal S1 detected by the current transformer CT is shown in FIG.
), the surge current component P and the fault current component Q
including. The detected signal S1 is applied to the pulse transformer 8 via the input protection section 7. The pulse transformer 8 provides the fault current component to the fault detection section 20 and the surge current component to the surge detection section 30 . In the failure detection section 20,
As shown in Figure 3(b), the Zener diode ZDI
and ZD2, a signal S2 in which the peak value of the surge current component is shortened is obtained (arrow R). The signal S2 is rectified by a rectifier W1, and a rectified signal S4 as shown in FIG. 3(d) is provided to an adder 41.

On the other hand, in the surge detection section 30, the surge current component P shown in FIG. 3(a) is rectified by the rectifier W2, so that a signal S3 shown in FIG. 3(C) is obtained. This signal S3
is also provided to adder 41.

In the LED driving section 40, the adder 41 receives the applied signal S.
3 and S4. Therefore, the signal S5 shown in FIG. 3(e) is obtained via the resistor R3, and this signal S5
drives the light emitting diode LED. As can be seen from FIG. 3(e), the signal S5 includes signal components S and T corresponding to each surge current component and fault current component,
An optical signal containing this information is transmitted to the display device 3 shown in FIG.
will be transmitted towards.

In this way, the single current transformer CT detects the signal S1 including the surge current component and the fault current component, and the pulse transformer 8 separates each signal, so there is no need to provide two current transformers. In addition, since signals containing surge current components and fault current components are converted into optical signals and transmitted to a display device, detection devices can be used near power transmission towers or substations where inductive noise is likely to occur. and the display device can be increased.

FIG. 4 is a circuit block diagram of a lightning detection and notification device showing another embodiment of the present invention. Referring to FIG. 4, the difference from the circuit shown in FIG. 1 is that the pulse transformer 8 shown in FIG.
1 and the surge detection section 31 are provided with filters F1 and F2 for separating current components. The failure detection unit 21 includes a low-pass filter F1 that passes a failure current component, a gain controller G1, and a rectifier W1.

Surge detection section 31 includes a bypass filter F2 that passes a surge current component, a gain controller G2, and a rectifier W2. Since the commercial frequency is 50 to 60Hz, the cutoff frequency of the low-pass filter F1 is 120 to 130Hz.
Set to z.

The cutoff frequency of bypass filter F2 is 120 to 1
It is set to 80Hz. The LED driving section 40 has a similar circuit configuration to the circuit 40 shown in FIG. 1, and operates similarly.

FIG. 5 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 4. Next, the operation will be explained with reference to FIGS. 4 and 5.

The signal Sl detected by the current transformer CT (Fig. 5(a)
) is given to each low-pass filter F1 and bypass filter F2. Therefore, in the fault detection section 21, a signal S6 indicating a fault current component as shown in FIG. 5(b) is obtained via the low-pass filter F1 and the gain controller G1.

This signal S6 is rectified by the rectifier W1 and is
) is obtained. On the other hand, the surge detection section 31
, a signal S7 indicating the surge current component is obtained, and this signal S7 is applied to the adder 41. Similar to the circuit shown in FIG.
7 and S8 are added, and the added signal is converted into an optical signal and transmitted.

FIG. 6 is a circuit block diagram of a lightning detection and notification device showing still another embodiment of the present invention. Referring to Figure 6,
Saturation type current transformer S for detecting the current I flowing through the lightning arrester
It includes a CT, an input protection section 7, a rectification section 50, and an LED drive section 60. In the embodiment shown in FIG. 6, unlike the previous two embodiments, the signal detected by the current transformer is converted into an optical signal without separating it into a surge current component and a fault current component. is being carried out. That is, since the saturated current transformer SCT is used as the current transformer, the maximum level of the surge current component of the detected signal is shortened. Therefore, conversion into an optical signal can be realized without separating into two current components.

FIG. 7 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 6. Next, the operation will be explained with reference to FIGS. 6 and 7.

The current {circle around (2)} flowing through the lightning arrester includes the surge current U and fault current V shown in FIG. 7(a). however,
Since the saturated current transformer SCT is used, the current transformer SC
The signal S11 detected by T has the waveform shown in FIG. 7(b). That is, the maximum peak value of the signal component corresponding to the surge current is reduced. As a result, the rectifier 50
This signal Sll is rectified in the step S11 to obtain the signal S12 shown in FIG. 7(c). The light emitting diode LED is driven by this signal S12, and the optically converted signal is transmitted.

It is pointed out that this embodiment also uses a single saturated current transformer SCK, and in addition, the circuit configuration is simplified because no separation process is required.

FIG. 8 is a circuit block diagram showing an example of the display device 3 shown in FIG. 1. Referring to FIG. 8, this display device includes a photoelectric conversion unit 70 and a failure detection unit 8 that detects a failure current.
0, and a surge detection section 90 that detects surge current. The photoelectric conversion unit 70 includes a photodetector PD that converts a transmitted optical signal into an electrical signal, and an npn (npn) transistor and resistors 72 and 73 connected in series between a power supply Vcc and ground. The failure detection 180 includes an amplifier 81, a waveform shaping circuit 82, a failure determination circuit 83, and a driver 84.
and a failure indicator 85. The surge detection section 90 includes a waveform shaping circuit 91, a surge determination circuit 92, and a driver 9.
3 and a surge counter 94.

In operation, the signal detected by the photodetector PD is n
Provided to the base of pn transistor 71. As a result, a fault current component flows from one end of the resistor 72 to the fault detection section 8.
0, and a surge current component is applied to the surge detection section 90 from the other end of the resistor 72. In the failure detection section 80,
After the fault current component is amplified by the amplifier 81, the waveform is shaped by the waveform shaping circuit 82. The failure determination circuit 83 determines whether a failure has occurred in the lightning arrester by determining whether the level of the failure current component exceeds a predetermined level. The determination result is the driver 84
and the fault indicator 85 is driven.

On the other hand, in the surge detection section 90 , the surge current component is waveform-shaped by a waveform shaping circuit 91 and provided to a surge determination circuit 92 . The surge determination circuit 92 detects the occurrence of a surge current by determining whether the surge current component exceeds a predetermined level. A signal indicating the detection result is given to the driver 93, and the surge counter 94 is driven.

[Effects of the Invention] As described above, according to the present invention, a current signal detected by a single current detection means is separated into a surge current component and a fault current component, and each separated electrical signal component is rectified. Since the signals are added together and converted into an optical signal, a lightning detection and notification device that can increase the distance between the current detection section and the notification section is obtained.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of a lightning detection and notification device showing an embodiment of the present invention. FIG. 2 is a conceptual diagram showing an example of application of the lightning detection and notification device according to the present invention. FIG. 3 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 1. FIG. 4 is a circuit block diagram of a lightning detection and notification device showing another embodiment of the present invention. FIG. 5 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 4. FIG. 6 is a circuit block diagram of a lightning detection and notification device showing still another embodiment of the present invention. FIG. 7 is a waveform diagram for explaining the operation of the lightning detection and notification device shown in FIG. 6. FIG. 8 is a circuit block diagram showing an example of the display device shown in FIG. 1. In the figure, 1 is a lightning arrester, 2 is a detection device, 3 is a display device, 20.21 is a failure detection section, 30.31 is a surge detection section, 40 is an LED drive section, CT is a current transformer, and SCT is a saturated transformer. The currents, ZDI, and ZD2 are Zener diodes, Fl is a low-pass filter, and F2 is a bypass filter. Patent applicant: Sumitomo Electric Industries, Ltd.

Claims (3)

[Claims] (1) It includes a lightning arrester and a single current detection means for detecting a current flowing through the lightning arrester due to the occurrence of a lightning strike, and the current flowing through the lightning arrester is divided into a surge current caused by a lightning strike and a fault current caused by a failure of the lightning arrester. a first separation means for separating the current detected by the current detection means into a surge current component and a fault current component; and a first separation means for separating the current detected by the current detection means into a surge current component and a fault current component; rectifying means for respectively rectifying; adding means for adding the currents rectified by the rectifying means; first converting means for converting the electrical signals added by the adding means into optical signals; and the first converting means. A lightning strike detection and notification device, comprising: a notification means connected to receive an optical signal converted by the converter, and reporting means for notifying the occurrence of a lightning strike and the occurrence of a failure of a lightning arrester in response to the converted optical signal. (2) It includes a lightning arrester and a saturation type current transformer connected to receive the current flowing through the lightning arrester, and the current flowing through the lightning arrester includes a surge current caused by a lightning strike and a fault current caused by a failure of the lightning arrester. a saturation current level of the current transformer is set between the maximum level of the surge current and the maximum level of the fault current, and a first conversion for converting the output current signal of the current transformer into an optical signal. and a notifying device connected to receive the optical signal converted by the converting device and reporting the occurrence of a lightning strike and the occurrence of a failure of a lightning arrester in response to the converted optical signal. . (3) The notification means is connected to receive the optical signal converted by the first conversion means, and a second conversion means that converts the optical signal into an electrical signal.
converting means; second separating means for separating the signal converted by the second converting means into a surge current component and a fault current component; and responding to the surge current component separated by the second separating means. a lightning strike determination means for determining the occurrence of a lightning strike; a failure determination means for determining the occurrence of a failure of the lightning arrester in response to the fault current component separated by the second separation means; the lightning strike determination means; 3. The lightning detection and notification device according to claim 1, further comprising display means for displaying the occurrence of a lightning strike and the occurrence of a failure of a lightning arrester determined by the failure determination means.