JP2021093658A - Power line carrier control system - Google Patents

Abstract

To detect the installation of the grounding for work without going to a site, and realize the stop of a power line carrier by remote control.SOLUTION: A power line carrier control system includes a reception level monitoring device 2 that detects the reception level in a power line carrier terminal device 13, a power control device 3 that switches between execution and cut-off of power supply to the power line carrier terminal device 13, and a remote control device 4 that receives the reception level detected by the reception level monitoring device 2 and transmits a control signal for switching the power supply to the power control device 3, and when the reception level drops by a predetermined range, the remote control device 4 transmits a control signal (cutoff signal) for cutting off the power supply to the power control device 3, and the power control device 3 that receives the control signal (cutoff signal) operates and cuts off the power supply to the power line carrier terminal device 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to a system for remotely controlling a power line carrier.

Conventionally, a power line carrier / power line carrier communication device that communicates using a power line as a transmission line is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-11153

By the way, regarding power line transportation, when the work grounding earth (also called "Otsu Earth" or "Otsu Class Earth") attached to the on-site equipment during transmission line work is used, it becomes the earth return method, and when it corresponds to the earth return method. Is required to apply for high frequency use based on Article 100 of the Radio Law and obtain permission from the Ministry of Internal Affairs and Communications. Therefore, in order to prevent the return route method to the ground, it is necessary to stop the power line carrier before performing the transmission line work.

To deal with the suspension of the power line carrier, workers go to the site where the power line carrier is installed and carry out the directly managed work by physically disconnecting the communication line, which is disadvantageous in labor productivity. There is a problem that it is large (in other words, a large amount of human and time loss). In addition, since it is difficult to deal with the daily power outage work for a long period of time when the power line carrier is carried out, it is necessary to stop the communication line continuously for a long period of time. There is a problem that the risk of simultaneous stoppage of two routes such as a line for a remote monitoring and control device in the event of a disaster increases.

Therefore, an object of the present invention is to provide a power line carrier control system that can detect the installation of a ground for work without going to the site and can realize a stop by remote control of the power line carrier. ..

In order to solve the above problem, the invention of claim 1 switches between a reception level monitoring device that detects a reception level in a power line carrier end station device and execution and interruption of power supply to the power line carrier end station device. It has a power supply control device for performing the operation, and a remote control device for receiving the reception level detected by the reception level monitoring device and transmitting a control signal for switching the power supply to the power supply control device. When the reception level drops by a predetermined width, the remote control device transmits a control signal for cutting off the power supply to the power control device, and the power control device receives the control signal. Is an operation, and the power supply to the power line transport terminal device is cut off, which is a power line transport control system.

The invention of claim 2 includes the input / output isolated type DC-DC converter and a relay circuit connected to the power supply control device in the power line transfer control system according to claim 1, and the power supply control device. Is connected to the power supply via the DC-DC converter, the power line carrier end station device is connected to the power supply via the relay contact of the relay circuit, and the power supply control device receives the control signal. The power supply to the relay circuit is cut off and the relay contact is opened, so that the power supply to the power line carrier end station device is cut off.

The invention of claim 3 is characterized in that, in the power line carrier control system according to claims 1 and 2, the predetermined width is 1 to 5 dBm.

The invention of claim 4 is characterized in that, in the power line transfer control system according to claims 1 to 3, the power supply control device is negatively grounded and the power line transfer end station device is positively grounded.

According to the invention of claim 1, it is detected without going to the site that a work grounding earth is attached to the field equipment based on a specific change in the reception level in the power line carrier end station device. At the same time, the power line carrier end station device can be stopped by remote control based on the detection, and the labor productivity related to the operation and management of the power line carrier device can be improved.

According to the invention of claim 2, an input / output isolated type DC-DC converter is interposed between the power supply and the power supply control device, and a relay contact is interposed between the power supply and the power line carrier terminal device. , Power supply to the power line carrier terminal device can be controlled without directly connecting the power control device and the power line carrier terminal device, and the power line can be controlled regardless of the polarity of the power control device and the power line carrier terminal device. It is possible to configure a mechanism for controlling the power supply to the carrier terminal device.

According to the invention of claim 3, it is possible to accurately detect that the work grounding earth is attached to the field equipment.

According to the invention of claim 4, it is possible to configure a mechanism for controlling the power supply to the power line carrier end station device by using the negative grounded power supply control device and the positive grounded power line carrier end station device. ..

It is a schematic block diagram of the power line carrier control system which concerns on embodiment of this invention. It is a block diagram of the power line carrier control system of FIG. It is a schematic block diagram of the remote control device of the power line carrier control system of FIG. It is a figure which shows the example of the reception level in the power line carrier end station apparatus in a normal state (when the ground for work ground is not installed with respect to a transmission line). It is a figure which shows the example of the transition of the reception level in a power line carrier terminal apparatus when one ground for work ground is installed with respect to a transmission line. It is a figure which shows the example of the transition of the reception level in a power line carrier terminal apparatus when a failure occurs in a transmission line. It is a figure which shows the schematic structure of the circuit related to the power-source control device in the case where the power line carrier terminal apparatus is positively grounded and the power supply control apparatus is negatively grounded. It is a timing chart which shows the operation of the power line carrier control system of FIG.

Hereinafter, the present invention will be described based on the illustrated embodiment.

FIG. 1 is a schematic configuration diagram of a power line carrier control system 1 according to an embodiment of the present invention. The power line carrier control system 1 is a system that remotely controls a power line carrier that communicates using a power line as a transmission line. In this embodiment, a transmission line 11 and a transmission line 12 are arranged between the electric station 10A and the electric station 10B, and the transmission lines 11 and 12 are used as transmission lines for power line transportation.

The power line transfer control system 1 is configured to be installed in each of the electric station 10A and the electric station 10B, and is a power line from a reception level monitoring device 2 that acquires the reception level of the power line carrier terminal device 13 and a communication power supply 14. Based on the information provided by the reception level monitoring device 2, it has a power supply control device 3 that controls the power supply to the carrier terminal device 13 and is installed in a remote location away from each of the electric stations 10A and 10B. It has a remote control device 4 for remotely operating the power supply control device 3.

The reception level monitoring device 2, the power supply control device 3, and the remote control device 4 each have a communication function, and the reception level monitoring device 2 and the remote control device 4 are freely configured to communicate with each other, and the power supply control device 3 and the remote control device 4 are remotely controlled. The device 4 is freely configured to communicate with the device 4. In this embodiment, the reception level monitoring device 2, the power supply control device 3, and the remote control device 4 can communicate freely via a communication network 20 such as the Internet or an intranet (for example, a local IP network). It is composed.

The power line carrier control system 1 is characterized in that it mainly includes a reception level monitoring device 2, a power supply control device 3, and a remote control device 4, and the mechanism itself for performing power line carrier has the same configuration as the conventional power line carrier. Although detailed description of the configuration equivalent to the conventional configuration is omitted, the configuration of this embodiment is roughly as follows (see FIG. 2).

The transmission lines 11 and 12 (specifically, the neutral line of the single-phase three-wire system drop lines; indicated as "white phase" in the figure) are drawn into the electric stations 10A and 10B and combined. It is connected to the power line carrier end station device 13 via a capacitor 15, a line coupling filter (EF) 16, and a balanced coupling filter (MF) 17 for a metal circuit, and further via a power line carrier security device 18. The transmission lines 11 and 12 are also connected to the substation equipment via a line trap 19.

The power line carrier end station device 13 is a device that functions as an end station in power line carrier that communicates using transmission lines 11 and 12 as transmission lines.

The communication power supply 14 is a facility that supplies power to the power line carrier terminal device 13, and is, for example, a DC distribution board.

Then, the power line transfer control system 1 of this embodiment switches between the reception level monitoring device 2 that detects the reception level in the power line transfer end station device 13 and the execution and interruption of power supply to the power line transfer end station device 13. A power control device 3 for performing the above operation, and a remote control device 4 for receiving the reception level detected by the reception level monitoring device 2 and transmitting a control signal for switching the power supply to the power supply control device 3. Then, when the reception level drops by a predetermined width, the remote control device 4 transmits a control signal (cutoff signal) for cutting off the power supply to the power supply control device 3, and the control signal (cutoff signal). The power supply control device 3 that received the above is operated so that the power supply to the power line carrier terminal device 13 is cut off.

The reception level monitoring device 2 collects the reception level of the power line carrier terminal device 13 and provides it to the remote control device 4. In this embodiment, the reception level monitoring device 2 detects the reception level of the signal superimposed on the transmission lines 11 and 12 and transmitted by the power line carrier end station device 13, and the detected reception level data (reception). A signal indicating the level) is transmitted to the remote control device 4 via the communication network 20.

The power control device 3 is a device that is interposed between the communication power supply 14 and the power line carrier end station device 13 to switch between executing and shutting off the power supply from the communication power supply 14 to the power line carrier end station device 13. Is.

The remote control device 4 monitors the state of the reception level in the power line carrier end station device 13 using the information provided from the reception level monitoring device 2, detects the change in the reception level, and sends the power line carrier end station device 13 to the power line carrier end station device 13. It is a device that executes a process related to a determination of power supply cutoff and also executes a process related to remote control of the power control device 3 based on the result of the determination. As shown in FIG. 3, the remote control device 4 mainly controls the data receiving unit 41, the command transmitting unit 42, the display unit 43, the input unit 44, the memory 45, the main task 46, and the like. A central processing unit 47 is provided.

The central processing unit 47 is configured by, for example, a processor using a CPU or the like, or is configured to realize each function according to a program stored in the memory 45.

The data receiving unit 41 receives the reception level data (signal representing the reception level) in the power line carrier terminal device 13 transmitted from the reception level monitoring device 2 via the communication network 20. The data receiving unit 41 transfers the received reception level data to the main task 46.

The command transmission unit 42 communicates to the power control device 3 a control signal transferred from the main task 46 for shutting off or restarting the power supply from the communication power supply 14 to the power line carrier terminal device 13. It is transmitted via the network 20.

The display unit 43 is, for example, a liquid crystal screen, and displays information regarding the states of the transmission lines 11 and 12.

The input unit 44 is, for example, a keyboard or a mouse, and receives an operation of a worker and transfers an operation signal to the central processing unit 47 or the main task 46.

The memory 45 is a storage device capable of storing various types of information and data, and functions as a storage area for reception level data received by the data receiving unit 41, and is used for determining the operation of the power supply control device 3 and for remote operation. It functions as a work area when executing related processes.

The main task 46 is a group of task programs for determining the operation of the power supply control device 3 and executing processing related to remote control. The main task 46 mainly includes a reception level determination task 46a, a cutoff signal generation task 46b, an alarm output task 46c, and a restart signal generation task 46d.

The reception level determination task 46a is a task of executing a process of determining whether or not a work ground is installed for the transmission lines 11 and 12 based on the reception level data transmitted from the reception level monitoring device 2.・ It is a program. The reception level determination task 46a receives the input of the reception level data transferred from the data reception unit 41, performs processing, and when it is determined that the ground for work is installed, the determination result is a cutoff signal generation task. Transfer to 46b.

Here, in the normal state, in other words, when the work grounding ground is not installed for the transmission lines 11 and 12, as shown in FIG. 4, the signal superimposed on the transmission line 11 and transmitted. The reception level in the power line carrier end station device 13 is stable at about −20 dBm. On the other hand, according to the knowledge of the inventor, when one ground for work is installed on the transmission lines 11 and 12, as shown in FIG. 5, a signal superimposed on the transmission line 11 is transmitted. The reception level of the power line carrier terminal device 13 is lowered by about 3 dBm to about -23 dBm as a result, and the reception level is stable at about -23 dBm while the ground for work is installed.

Therefore, the reception level determination task 46a determines that the work grounding ground has been installed for the transmission lines 11 and 12 when the degree of decrease in the reception level in the power line carrier end station device 13 is within a predetermined range. .. When the ground for work is installed in two places, the reception level drops by about 3 dBm from the stable state at about -23 dBm when installed in one place, and as a result, it becomes about -26 dBm. Therefore, the reception level is stable at about -26 dBm while the ground for work is installed at two places.

The degree of reception level in the power line carrier end station device 13 at normal times and the degree of decrease in reception level when a ground for work is installed are the characteristics of equipment related to power transmission and distribution, and equipment related to power line carrier communication. It is conceivable that the above example is not limited to the above example, depending on the characteristics of the above and the degree of influence on various facilities when the ground for work is installed. Therefore, the degree of decrease in the reception level, especially when the work ground is installed, is the reception level actually observed in each power line carrier end station device 13 when the work ground is installed. It may be set for each power line carrier end station device 13 based on the actual degree of decrease. The degree of decrease in reception level (predetermined width or predetermined value) when a work ground is installed on the transmission lines 11 and 12 is referred to as "earth installation decrease level".

Further, when a failure occurs in the transmission lines 11 and 12 due to, for example, a lightning strike, as shown in FIG. 6, the reception level of the signal superimposed on the transmission line 11 and transmitted in the power line carrier end station device 13 is set. Significantly, specifically, for example, it decreases by about 40 dBm to about -60 dBm (or decreases by 40 dBm or more to -60 dBm or less). Therefore, in the reception level determination task 46a, when the degree of decrease in the reception level in the power line carrier end station device 13 is within a predetermined width, a work grounding ground is installed for the transmission lines 11 and 12. If it exceeds the predetermined width, it is judged that the transmission lines 11 and 12 have failed.

The degree of decrease in reception level when a failure occurs in transmission lines 11 and 12 is based on the actual degree of decrease in reception level actually observed in each power line carrier terminal device 13 when a failure occurs. It may be set for each power line carrier end station device 13. The degree of decrease in reception level (predetermined width or predetermined value) when a failure occurs in transmission lines 11 and 12 is referred to as "failure occurrence reduction level".

Based on the inventor's knowledge and the above, the reception level determination task 46a is for work with respect to the transmission lines 11 and 12 when, for example, the reception level in the power line carrier end station device 13 drops within a range of about 1 to 5 dBm. It is judged that the grounding ground is installed, or when the reception level drops within the range of about 2 to 4 dBm, it is judged that the grounding for work is installed, or it is lowered by about 3 dBm. If this happens, it is preferable to determine that the ground for work grounding has been installed.

Then, the reception level determination task 46a analyzes the reception level data transmitted from the reception level monitoring device 2 and transferred from the data reception unit 41, and the reception level in the power line carrier end station device 13 is set to the ground installation lowering level. When the decrease corresponding to the above is achieved, an instruction (referred to as a “cutoff signal generation instruction”) for creating a signal for cutting off the power supply to the power line carrier end station device 13 is transferred to the cutoff signal generation task 46b. The reception level determination task 46a also transfers the cutoff signal generation instruction to the alarm output task 46c.

On the other hand, the reception level determination task 46a does not transfer the cutoff signal generation instruction when the reception level in the power line carrier end station device 13 drops to a level that does not correspond to the ground installation lowering level.

The cutoff signal generation task 46b is a task program that executes a process of generating a signal for remotely controlling the power supply control device 3 based on an instruction transferred from the reception level determination task 46a. The cutoff signal generation task 46b starts processing in response to the input of the cutoff signal generation instruction transferred from the reception level determination task 46a, and cuts off the power supply from the power control device 3 to the power line carrier terminal device 13 by remote control. A signal (referred to as a “cutoff signal”) is generated and transferred to the command transmission unit 42.

The alarm output task 46c is a task program that executes a process of outputting information regarding the status of the transmission lines 11 and 12 based on the instruction transferred from the reception level determination task 46a. The alarm output task 46c starts processing in response to the input of the cutoff signal generation instruction transferred from the reception level determination task 46a, and information indicating that the ground for work is installed for the transmission lines 11 and 12. Is output. The alarm output task 46c displays, for example, a message indicating that the ground for work is installed on the display unit 43 included in the remote control device 4, or from a speaker (not shown) provided in the remote control device 4. Make a sound.

The restart signal generation task 46d is a task program that executes a process of generating a signal for remotely controlling the power supply control device 3 based on an instruction given via the input unit 44. The restart signal generation task 46d starts processing in response to the input of an instruction given by the operation of the input unit 44 by the worker, and restarts the power supply from the power control device 3 to the power line carrier terminal device 13 by remote control. A signal (referred to as a “restart signal”) for the purpose is generated and transferred to the command transmission unit 42.

Here, as a mechanism for switching between execution and cutoff of power supply to the power line carrier end station device 13, the power control device 3 may be directly connected to the power line carrier end station device 13 as it is, but the power line carrier end station device 13 may be directly connected. When the device (also called "ribter") constituting the main part of the power supply control device 3 is negatively grounded while the power supply control device 3 is positively grounded, the power supply control device 3 is directly connected to the power line carrier terminal device 13. Cannot connect directly. To solve this problem, that is, when the power line carrier end station device 13 is positively grounded and the equipment constituting the main part of the power supply control device 3 is negatively grounded, the circuit related to the power supply control device 3 The schematic configuration is shown in FIG. In the configuration shown in FIG. 7, the power supply control device 3 is negatively grounded, and the power line carrier end station device 13 is positively grounded.

In the configuration shown in FIG. 7, the input / output isolated type DC-DC converter 7 and the relay circuit 9 connected to the power supply control device 3 are provided, and the power supply control device 3 passes through the DC-DC converter 7. It is connected to the power supply (distribution board 5), and the power line carrier end station device 13 is connected to the power supply (distribution board 5) via the relay contact 91 of the relay circuit 9 to receive the control signal (cutoff signal). The power supply control device 3 cuts off the power supply to the relay circuit 9 and the relay contact 91 opens, so that the power supply to the power line carrier end station device 13 is cut off.

The distribution board 5 is a facility corresponding to the communication power supply 14 in FIGS. 1 and 2, and is connected to the power supply side terminal 6 to transmit DC power of DC-48V (note that DC-24V is also conceivable). It is a DC distribution board that is branched and supplied. The polarity of the power supply supplied from the distribution board 5 is positive grounding.

The DC-DC converter 7 is an input / output isolated type DC-DC converter, and can have dielectric strength. Therefore, the DC-DC converter 7 is interposed between the distribution board 5 and the power supply control device 3 to enable connection between the distribution board 5 and the power supply control device 3, which are devices having different polar grounds. (That is, it enables the conversion of polarity, in other words, it enables the elimination of the difference in polarity of the device). In the example shown in FIG. 7, the DC-DC converter 7 converts DC 48V to DC 24V (100W) (or, when the distribution board 5 is DC-24V, DC 24V to DC 24V (or) Convert to 50W)). Reference numeral 22 in FIG. 7 is a fuse.

The power line carrier terminal device 13 is connected to the device side terminal 8 connected to the power supply side terminal 6 to which power is supplied from the distribution board 5, that is, the power supply side terminal 6 and the device side terminal from the distribution board 5. Power is supplied via 8. Since the polarity of the power supply supplied from the distribution board 5 is positively grounded and the power line carrier end station device 13 is also positively grounded, it is not necessary to change the polarity between them.

A relay contact 91 is provided between the power supply side terminal 6 and the device side terminal 8. By opening and closing the relay contact 91, the power supply to the power line carrier terminal device 13 is switched between execution and interruption. The relay contact 91 is normally closed. The power supply to the power line carrier end station device 13 is executed when the relay contact 91 is closed, and the power supply to the power line carrier end station device 13 is cut off when the relay contact 91 is open.

The power control device 3 includes a communication unit 31 for communicating with the remote control device 4 via the communication network 20, a power input unit 32 for receiving DC power input via the DC-DC converter 7, and the power input unit 32. It has a control unit 33 that controls execution and interruption of power supply to an external circuit.

The power supply control device 3 is connected to a DC-DC converter 7 connected to a power supply side terminal 6 to which power is supplied from the distribution board 5, that is, the power supply side terminal 6 and the DC-DC converter from the distribution board 5. Power is supplied via 7. The power control device 3 normally executes power supply to the external circuit, and cuts off the power supply to the external circuit when the cutoff signal transmitted from the remote control device 4 is received via the communication unit 31.

A relay circuit 9 is connected to the control unit 33 of the power supply control device 3 as an external circuit. The relay circuit 9 normally operates when power is supplied from the power control device 3 to close the relay contact 91, and the power control device 3 receives a cutoff signal to cut off the power supply to the relay circuit 9 as an external circuit. Then, the relay contact 91 is opened. When the relay contact 91 is opened, the power supply is cut off and the power line carrier terminal device 13 is stopped.

Next, the operation, operation, and the like of the power line carrier control system 1 having such a configuration will be described with reference to FIG. The reception level values in the following description are all examples.

First, as usual, power is supplied from the power control device 3 to the relay circuit 9 (step S1), and the relay contact 91 is closed (step S2), thereby supplying power to the power line carrier terminal device 13. The supply is executed (step S3), and the transmission lines 11 and 12 are used as transmission lines to perform power line carrier communication (step S4). At this time, if the work ground is not installed for the transmission lines 11 and 12, the reception level determination task 46a is transmitted from the reception level monitoring device 2 (step S5) and is transmitted from the data reception unit 41. Based on the transferred reception level data, it is determined that the reception level in the power line carrier end station device 13 is stable at about -20 dBm, and that no work ground is installed for the transmission lines 11 and 12. To do.

From the above state, when the ground for work is installed on the transmission lines 11 and 12, the reception level in the power line carrier end station device 13 is lowered by about 3 dBm, and as a result, it becomes about -23 dBm. At this time, in the reception level determination task 46a, the reception level in the power line carrier terminal device 13 is 3 dBm based on the reception level data transmitted from the reception level monitoring device 2 (step S6) and transferred from the data reception unit 41. It is stable in a state where it has decreased to about -23 dBm as a result, and it is judged that the ground for work grounding has been installed for the transmission lines 11 and 12. Then, the reception level determination task 46a transfers the cutoff signal generation instruction to the cutoff signal generation task 46b and the alarm output task 46c (step S7).

The alarm output task 46c, which receives the input of the cutoff signal generation instruction, displays a message indicating that the ground for work is installed on the display unit 43 provided in the remote control device 4, or is provided in the remote control device 4. Sound is output from a speaker (not shown) (step S8).

Upon receiving the input of the cutoff signal generation instruction, the cutoff signal generation task 46b generates a cutoff signal and transfers it to the command transmission unit 42 (step S9). The command transmission unit 42 that has received the input of the cutoff signal transmits the cutoff signal to the power supply control device 3 via the communication network 20 (step S10). Then, the power control device 3 that receives the input of the cutoff signal cuts off the power supply to the relay circuit 9 (step S11), whereby the relay contact 91 is opened (step S12), and the power line carrier end station device 13 The power supply to is cut off (step S13), and the power line carrier end station device 13 is stopped (step S14).

After that, the ground for the work ground installed for the transmission lines 11 and 12 is removed, and the input unit 44 is operated by the worker to give an instruction corresponding to the restart of the power supply to the power line carrier terminal device 13. Is input, the restart signal generation task 46d generates a restart signal and transfers it to the command transmission unit 42 (step S15).

Upon receiving the input of the restart signal, the command transmission unit 42 transmits the restart signal to the power supply control device 3 via the communication network 20 (step S16). Then, the power control device 3 that has received the input of the restart signal restarts the power supply to the relay circuit 9 (step S17), whereby the relay contact 91 is closed (step S18), and the power line carrier end station device 13 The power supply to the power line carrier is restarted (step S19), and the power line carrier end station device 13 is activated (step S20). Then, as usual, the transmission lines 11 and 12 are used as transmission lines to perform power line carrier communication.

Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above-described embodiment, and even if there is a design change or the like within a range that does not deviate from the gist of the present invention. Included in the invention.

For example, when a plurality of remote control devices 4 are arranged to monitor power line carrier communication performed between a plurality of electric stations, communication with the plurality of remote control devices 4 is performed via a communication network 20. A comprehensive control device (not shown) that manages the plurality of remote control devices 4 may be installed. In this case, the state of the power line carrier communication performed between a plurality of electric stations in the management target area can be centrally managed, and the remote control device 4 can be operated from the comprehensive control device. It can also be configured.

1 Power line transfer control system 2 Reception level monitoring device 3 Power control device 31 Communication unit 32 Power input unit 33 Control unit 4 Remote control device 41 Data reception unit 42 Command transmission unit 43 Display unit 44 Input unit 45 Memory 46 Main task 46a Reception level Judgment task 46b Shutoff signal generation task 46c Alarm output task 46d Resume signal generation task 47 Central processing unit 5 Distribution board 6 Power supply side terminal 7 DC-DC converter 8 Device side terminal 9 Relay circuit 91 Relay contact 10A Electric station 10B Electric station 11 Transmission line 12 Transmission line 13 Power line carrier terminal equipment 14 Communication power supply 15 Coupling capacitor 16 Line-to-line coupling filter (EF)
17 Equilibrium coupling filter (MF) for metal circuits
18 Power line carrier security device 19 Line trap 20 Communication network

Claims (4)

A reception level monitoring device that detects the reception level in the power line carrier end station device, and
A power control device that switches between executing and shutting off the power supply to the power line carrier terminal device,
It has a remote control device that receives the reception level detected by the reception level monitoring device and transmits a control signal for switching the power supply to the power control device.
When the reception level drops by a predetermined width, the remote control device transmits a control signal for cutting off the power supply to the power control device, and the power control device that receives the control signal receives the control signal. It operates and the power supply to the power line carrier terminal device is cut off.
A power line carrier control system characterized by this. Input / output isolated DC-DC converter and
It has a relay circuit connected to the power supply control device, and has
The power supply control device is connected to the power supply via the DC-DC converter, and the power supply control device is connected to the power supply.
The power line carrier terminal device is connected to the power supply via a relay contact of the relay circuit.
When the power supply control device that receives the control signal cuts off the power supply to the relay circuit and the relay contact is opened, the power supply to the power line carrier end station device is cut off.
The power line carrier control system according to claim 1. The predetermined width is 1 to 5 dBm.
The power line carrier control system according to claim 1 or 2. The power supply control device is negatively grounded.
The power line carrier terminal device is positively grounded.
The power line carrier control system according to claim 2.

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