KR102105630B1 - Power line Communication Using Neutral Wire - Google Patents

Abstract

The present invention relates to a power line communication (PLC) technology using a neutral wire. More specifically, provided is a PLC system, which comprises a PLC extension modem, including a slave module connected to a master modem with a power line to communicate, and separating a PLC signal among signals transmitted through the power line to transmit the PLC signal to a master module, and a master module communicating with a slave modem by loading the received PLC signal on the power line. Two PLC extension modems are connected to each other with a distribution panel in between, and the PLC extension modem communicates through the neutral line of the power line. By varying a frequency of the PLC signal on one side and the other side around the distribution panel, PLC signals for each group are operated.

Description

Power line communication using neutral wire

The present invention is a power line communication technology using a neutral wire, and more specifically, it is connected to a master modem with a power line for communication, and separates a PLC (power line communication) signal from signals transmitted through the power line to master the PLC signal. It includes a slave module for transmitting to the PLC, and a PLC extension modem including a master module for communicating with a slave modem by placing the PLC signal received from the slave module on a power line, and the PLC extension modems are connected to each other by two. , The PLC extension modem communicates through a neutral line of a power line, and relates to a PLC system characterized by operating PLC signals for each group by varying the frequency of PLC signals on one side and the other side around the distribution panel.

Power Line Communication (PLC) is a technology that transmits data using a power line that supplies power as a physical communication medium.It enables data networking by connecting power line communication equipment to an existing power infrastructure without a separate dedicated communication line. It has the advantage of making it.

1 is a diagram of a PLC system including one PLC master modem, one or more PLC slave modems, and a distribution panel. Referring to FIG. 1, the PLC communication system is composed of a PLC master modem connected to an external Internet network via an Ethernet method, and a plurality of PLC slave modems communicating with the PLC master modem and power lines. PLC slave modems are connected to terminals to send and receive data. In addition, the power line network may include a distribution panel for branching power by load.

In general, the PLC communication uses a method of superimposing and transmitting a high-frequency PLC communication signal in the 2 MHz to 30 MHz band to a commercial power signal in the 50 Hz to 60 Hz band. For example, there are HPGP (HomePlug Green PHy) method, HPAV (HomePlug Audio Video) method, and the like. Meanwhile, in the recently developed HomePlug AV2 (HPAV2) method, a high-frequency PLC communication signal in the 30 MHz to 86 MHz band is used. Hereinafter, it will be described on the assumption that the frequency band used for PLC communication is 2 MHz to 30 MHz.

In addition, PLC communication includes narrow band (kHz band) and broadband power line communication (MHz band) depending on the modulation frequency band of the PLC signal, low / medium speed (less than 1 Mbps class) and high speed (more than 1 Mbps class) power line communication, depending on the communication speed. It is divided into low voltage and high voltage power line communication, etc. according to the applied power grid.

Particularly, low-voltage power line communication is widely applied to the construction of an AMI (Advanced Metering Infrastructure) network as a method using a low-voltage distribution line for customers as a physical medium.

FIG. 2 is a diagram showing that the switch of the distribution panel is opened in FIG. 1 and the signal line S of the power line is disconnected. The switchboard operates by opening or shorting the switch in the process of branching power by load. As shown in FIG. 2, when the switch of the distribution panel is opened, the signal line S of the power line is cut off, and thus PLC communication is disconnected on the right side of the distribution panel.

As a method for overcoming this limitation, it is possible to prevent disconnection of PLC signals at both ends of the distribution panel by using an external coupler and a separate communication line at both sides of the distribution panel as shown in FIG. 3. However, in this method, a separate coupler needs to be added to the outside, and additional equipment such as a separate communication network needs to be installed, resulting in a complicated configuration and inconvenient installation.

The present invention has been made to solve the above-described problems, and has the following objectives.

An object of the present invention is to enable communication of a power line between distribution boards without installing additional equipment such as a separate communication network by using a ground magnetic field communication method using a neutral line (N) of the power line.

In addition, an object of the present invention is to prevent a PLC signal from being attenuated or lost in a neutral wire by configuring a neutral wire coupler connected to a neutral wire as a non-contact coupler.

In addition, the present invention is to form a PLC network through a single power line network, and has an object to prevent collision between master modem signals by operating the PLC signals of one side and the other with the center of the distribution panel differently.

Further, an object of the present invention is to solve the distinction of PLC signals by software by setting the network group ID in the header portion of the PLC signal packet to distinguish them.

In addition, the present invention, the PLC modem includes a group discrimination unit for determining the network group ID from the PLC signal, it is an object to screen and process the PLC signal used in the network group.

In addition, the present invention includes a signal processing unit for varying the signal processing according to the network group ID in which the PLC extension modem is set to generate a PLC signal by varying the frequency band according to the network group ID, or in the header portion of the PLC signal packet, It is an object to implement a PLC system that operates by differently controlling PLC signals for each network group by generating the network group IDs differently.

As a means for solving the above-described problems, the present invention has an embodiment with the following features.

The present invention is connected to a master modem with a power line to communicate, and separates a PLC (power line communication) signal from a signal transmitted through the power line, and transmits the PLC signal to the master module from the slave module and the slave module. A PLC extension modem including a master module that communicates with a slave modem by carrying the received PLC signal on a power line, and the PLC extension modems are connected to each other via a distribution panel, and the PLC extension modem is connected through a neutral line of the power line. It is characterized by communicating.

In addition, the present invention, the first PLC extension modem located on one side of the distribution panel, the slave module is connected through a signal line coupler connected to the signal line of the power line, the master module is connected through a neutral line coupler connected to the neutral line of the power line, the distribution panel The second PLC extension modem located on the other side of the is characterized in that the slave module is connected through a neutral line coupler connected to the neutral line of the power line, and the master module is connected through a signal line coupler connected to the signal line of the power line.

In addition, the neutral wire coupler is characterized in that the non-contact coupler.

In addition, the present invention is characterized in that a PLC network is formed for each group by forming a PLC network through a single power line network, but different PLC signals of one side and the other side around the distribution panel.

The PLC signal for each group is characterized by different frequency bands or by setting a network group ID in a header portion of the PLC signal packet.

The PLC extension modem includes a setting unit for setting a network group ID, a group determining unit for determining a network group ID, and a signal processing unit for different signal processing according to the network group ID set in the setting unit.

The signal processing unit is configured to generate a PLC signal by varying the frequency band according to the network group ID, or by generating a different network group ID in the header portion of the PLC signal packet.

The PLC communication method of the present invention includes a power line communication (PLC) communication through a neutral line of a power line with a distribution panel interposed therebetween, comprising: a first signal line communication step of receiving a PLC signal from a master modem through the signal line of the power line; A neutral line communication step of transmitting the PLC signal to the other side of the distribution panel through the neutral line of the power line; And a second signal line communication step of transmitting the PLC signal received from the other side of the distribution panel through the neutral line to the slave modem through the signal line of the power line. It characterized in that it comprises a.

In addition, the PLC communication method of the present invention is characterized in that the PLC communication method is operated with different frequency bands of the PLC signal on one side and the other centering on the distribution panel.

In addition, the PLC communication method of the present invention is characterized by generating the network group IDs differently in the header portions of the PLC signal packets on one side and the other side centering on the distribution panel.

The present invention has an effect of enabling the communication of power lines sandwiched between distribution boards without installing additional equipment such as a separate communication network by using a ground magnetic field communication method using a neutral line (N) of power lines.

In addition, the present invention has an effect of preventing a PLC signal from being attenuated or lost in the neutral line by configuring a neutral line coupler connected to the neutral line as a non-contact coupler.

In addition, the present invention, by forming a PLC network through a single power line network, has the effect of preventing collision between the master modem signal by operating the PLC signal on one side and the other with the center of the distribution panel.

In addition, the present invention derives an effect of solving the distinction of PLC signals with software by setting the network group ID in the header portion of the PLC signal packet to distinguish them.

In addition, the present invention has the effect that the PLC modem includes a group discrimination unit for determining the network group ID from the PLC signal, and selects and processes the PLC signal used for the network group.

In addition, the present invention includes a signal processing unit for varying the signal processing according to the network group ID in which the PLC extension modem is set to generate a PLC signal by varying the frequency band according to the network group ID, or in the header portion of the PLC signal packet, By generating the network group IDs differently, it is possible to implement a PLC system that operates with different PLC signals for each network group.

1 is a diagram of a PLC system including one PLC master modem, one or more PLC slave modems, and a distribution panel.
FIG. 2 is a view showing that the switch of the distribution panel in FIG. 1 is opened and the signal line S of the power line is disconnected.
FIG. 3 is a diagram for PLC communication by connecting an external coupler and a separate communication line in order to solve PLC failure due to disconnection of a signal line in FIG. 2.
4 is a diagram for PLC communication using a neutral line of a power line according to an embodiment of the present invention
5 is a diagram for a PLC extension modem A and a PLC extension modem B with a distribution panel therebetween, according to an embodiment of the present invention.
FIG. 6 is a diagram of operating a PLC signal for each group in order to prevent collision between master modem signals due to a short circuit in the switchboard in FIG. 4.
7 is a block diagram of a PLC slave modem according to an embodiment of the present invention
8 is a block diagram of a PLC master modem according to an embodiment of the present invention.
9 is a block diagram of a PLC extension modem according to an embodiment of the present invention
10 is a diagram of a PLC signal packet according to an embodiment of the present invention

The meaning of the terms described in this specification should be understood as follows.

It should be understood that a singular expression includes a plurality of expressions unless the context clearly defines otherwise, and the terms "first", "second", etc. are intended to distinguish one component from another component, The scope of rights should not be limited by these terms.

It should be understood that terms such as “include” or “have” do not preclude the presence or addition possibility of one or more other features or numbers, steps, actions, components, parts or combinations thereof.

It should be understood that the term “at least one” includes all possible combinations from one or more related items. For example, the meaning of “at least one of the first item, the second item, and the third item” means 2 of the first item, the second item, and the third item, as well as each of the first item, the second item, and the third item. Any combination of items that can be presented from more than one dog.

The power line network includes a single-phase or three-phase four-wire type, and the signal line means any one of R, S, and T-phase lines in a three-phase four-wire type.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a diagram for PLC communication using a neutral line of a power line according to an embodiment of the present invention.

Referring to FIG. 4, the PLC system provided by the present invention is connected to an external Internet and operates as a gateway as a gateway, a PLC master modem 220, a PLC master modem connected by a power line to communicate, and among the signals transmitted through the power line It includes a PLC extension modem (100) that separates the PLC signal and loads the PLC signal on a power line, and one or more PLC slave modems (210) connected and communicating with a PLC master modem and a PLC extension modem with a power line. In addition, the PLC master modem 220, the PLC slave modem 210, and the PLC extension modem 100 are connected to a power line through a coupler CP, and the power line may be disconnected by opening and closing a switch in the distribution panel. However, the line disconnected by the opening and closing of the switch is the signal line (S) and the neutral line (N) is not disconnected.

The PLC extension modem A (100a) is connected to one side and the PLC extension modem B (100b) is connected to the other side with the distribution panel interposed therebetween. PLC extension modems A and B are for convenience of explanation, and do not differ in configuration. However, the connection method of the power line using a coupler (CP) is different.

As shown in FIG. 4, most modems are connected to the signal line S through a coupler CP. This is because the neutral wire (N) is connected to the ground terminal at regular intervals, and because the loss or attenuation of the PLC signal is severe, it is not suitable for using PLC communication. Meanwhile, in the case of a PLC system including a switchboard (or a switchboard), the signal line S may be cut off as the switch of the switchboard is opened. When the signal line S is disconnected, PLC communication is disabled. However, the neutral line (N) is not disconnected by the switch opening of the switchboard. In view of this, the present invention is intended to propose a method for smooth communication without additional installation of a separate communication network by performing PLC communication using a neutral line (N) in a PLC system with a switchboard in between.

5 is a diagram for a PLC extension modem A and a PLC extension modem B with a distribution panel therebetween, according to an embodiment of the present invention.

Referring to FIG. 5, the PLC extension modems 100a and 100b are configured by integrating the slave module 110 serving as a slave modem and the master module 120 serving as a master modem, and the slave module 110. , A master module 220, and a connection unit 130 connecting the slave module and the master module.

First, looking at the PLC extension modem A (100a) located on the left side of the distribution panel, the PLC slave module (110a) is connected to the signal line (S) through the signal line coupler (111a). The PLC slave module 110a receives the PLC signal from the PLC master modem 220. The received PLC signal is transmitted to the PLC master module 120a through the connection unit 130a. The transmitted PLC signal is transmitted to the right side of the switchboard through the neutral line coupler 121a connected to the neutral line N. The signal line coupler and the neutral line coupler are different according to the wiring method, but the neutral line coupler is preferably composed of a non-contact coupler. Because, as described above, the neutral line (N) is connected to the ground terminal at regular intervals, resulting in severe loss or attenuation of the PLC signal. Therefore, it is useful to configure the non-contact coupler to prevent the PLC signal from being attenuated or lost in the neutral wire. As shown in FIG. 5, the coupler includes a coupling transformer that combines and separates a PLC signal from a power signal, and a capacitor that constitutes an LC filter.

Next, looking at the PLC extension modem B (100b) located on the right side of the distribution panel, the PLC slave module (110b) is connected to the neutral line (N) through the neutral line coupler (111a). The PLC slave module 110a receives the PLC signal from the PLC extension modem A 100a located on the left side of the distribution panel, and more specifically, the PLC master module 120a through the neutral line N. The received PLC signal is transmitted to the PLC master module 120b through the connection unit 130b. The transmitted PLC signal is transmitted to the PLC slave modem 210 located on the right side through the signal line coupler 121b connected to the signal line S.

As described above, the neutral line (N) is not suitable for PLC communication due to attenuation or loss compared to the signal line (S), but at short distances between switchboards, it is not a problem to communicate with the PLC through the neutral line (S). Does not.

On the other hand, when the switch of the distribution panel is opened through the method of connecting the PLC extension modem to the neutral line (N) as a coupler, the problem of disconnecting the PLC communication is solved, but a problem may occur when the switch of the distribution panel is shorted. .

FIG. 6 is a diagram for operating a PLC signal for each group in order to prevent collision between master modem signals due to a short circuit in the switchboard in FIG. 4.

Referring to FIG. 6, when the switch of the distribution panel is short-circuited, there is a problem that two or more master modems exist through one communication network.

It is not possible to operate more than one master modem in one communication network, because a communication network having a master slave structure operates communication in a 1: N manner in which one master modem and a plurality of slave modems communicate, so more than one master modem If this exists, communication collision between the master modems and one slave modem receive communication signals from two or more master modems, thus causing collision.

In order to prevent such a collision, the PLC system of the present invention operates PLC signals for each group by differentiating PLC signals of one side and the other side around the distribution panel. The frequency band of commercial PLC communication generally uses 2MHz ~ 30MHz, but the group-specific PLC signals physically mean different frequency bands within the above frequency bands. For example, the PLC signal of the network group 'A' uses a frequency band of 2MHz to 10MHz, and the PLC signal of the group 'B' refers to a frequency band of 15MHz to 25MHz.

7 is a block diagram of a PLC slave modem according to an embodiment of the present invention, and FIG. 8 is a block diagram of a PLC master modem according to an embodiment of the present invention.

The PLC modem is classified into a master modem and a slave modem according to its role, but its detailed configuration is generally configured in common.

Hereinafter, a PLC modem will be described with reference to FIG. 7 with a focus on a PLC slave modem.

The PLC slave modem provided by the present invention includes a coupler 211, a group discrimination unit 212, a control unit 213, a setting unit 214, and a signal processing unit 215.

The coupler 211 is a device that combines or separates PLC signals and power signals transmitted and received through power lines S and N. Since PLC communication is a power line that is already energized, it has a special and random signal or wavelength through which the current flows, and the coupler 211 reduces the interference to this wavelength so that the signal is loaded on the power line without distortion.

The group discrimination unit 212 determines the group ID of the PLC signal extracted from the coupler 211. As described above, in the PLC system provided by the present invention, PLC signals are operated differently for each network group. Physically, they have PLC signals with different frequency bands for each group. Physically, since the frequency band is different according to the group of PLC signals, it is also possible to determine the group of PLC signals using a filter. In addition, looking at this from the perspective of the digital domain, as shown in FIG. 10, the network group ID may be set in the header portion of the PLC signal packet to differentiate the PLC signals for each network group. The group discrimination unit 212 may search the header portion of the PLC signal packet to determine the group ID of the PLC signal in software. However, in this case, the group ID of the PLC signal may be determined only after the PLC signal is converted into a digital signal through the signal processing unit 215 to be described later.

The control unit 213 is in charge of overall control of the PLC slave modem 210, and the PLC signal determined by the group determining unit 212 selectively selects the PLC signal according to the set value of the setting unit 214, the signal processing unit To pass on.

The setting unit 214 is a part for setting a group of networks to which the PLC slave modem 210 belongs. The setting value of the setting unit 214 is transmitted to the above-described control unit 213. For example, if the PLC slave modem is included in the network group 'B', the setting value is set to 'B', and the control unit has the group ID of the PLC signal operated in the network group 'B' according to the setting value. Only PLC signals corresponding to 'B' are selected and transmitted to the signal processing unit.

The signal processing unit 215 includes a filter amplifier modulation circuit, converts an analog signal into a digital signal under the control of the control unit 213, and converts a digital signal into an analog signal. In the process of converting to a digital signal or an analog signal, the signal processing unit 215 converts the digital signal and the analog signal according to the group ID of the corresponding PLC signal according to the setting value of the setting unit 214 under the control of the control unit 213. . That is, when the group ID of the PLC signal corresponds to 'B', it is modulated with an analog signal in a frequency band suitable for B. In the process of converting to a digital signal, B is generated in the network ID in the header of the signal packet. The communication with the terminal communicates with a digital signal, and the PLC signal transmitted through the power line is converted into an analog signal and carried on the power line through a coupler.

9 is a block diagram of a PLC extension modem according to an embodiment of the present invention.

Referring to FIG. 9, the PLC extension modem 100 is a configuration in which the slave module 110 serving as a slave modem and the master module 120 serving as a master modem are integrated, and the slave module 110 and master It includes a module 220, a connecting portion connecting the slave module and the master module.

The functions of the group discrimination unit, the control unit, the setting unit, the signal processing unit, and the coupler constituting the slave module 110 and the master module 220 are not significantly different from the detailed configuration and functional aspects of the PLC modem described above. Is omitted.

Referring to Figures 6 to 9, when explaining the principle of operating by operating a different PLC signal for each network group in the PLC system of the present invention,

6, the left side of the distribution panel is a network group 'A', the right side is a network group 'B', and the group 'A' communicates with a group A PLC signal, and the header portion of the PLC signal packet is a network ID. Is 'A', group 'B' communicates with PLC signal of group B, and the header part of the PLC signal packet has a network ID of 'B'. As shown in Fig. 6, the PLC signals used in the network group A and group B show different frequency bands. However, the PLC signal of group A and the PLC signal of group B coexist on the power line forming a single power line network. However, the PLC master modem 220, the PLC slave modem 210, and the PLC extension modem 100 can set a network group through a setting unit. The PLC master modem and slave modem forming the group A and the slave module 110a of the PLC extension modem A are set to group A, and the master module 120b and PLC slave modem of the PLC extension modem B forming the group B are excluded. Set as group B.

The setting value of the setting unit is transmitted to the control unit, and the control unit selects only the PLC signal of the corresponding group and communicates with the terminal according to the group setting value, and the signal processing unit 215 controls the digital signal according to the group ID of the corresponding PLC signal under the control of the control unit. And convert it to an analog signal. As a result, the PLC system of the present invention can communicate smoothly through the switchboard by communicating through the neutral line (N), and at the same time, it has an effect of preventing movement between master modems.

It should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the claims of the present invention. .

100: PLC extension modem
110: slave module
111: coupler
112: group discrimination unit
113: control unit
114: setting unit
115: signal processing unit
120: master module
121: coupler
122: group discrimination unit
123: control unit
124: setting unit
125: signal processing unit
130: connection
210: PLC slave modem
220: PLC master modem

Claims (15)

Connected to the master modem with a power line to communicate, separate the PLC (power line communication) signal from the signal transmitted through the power line and transmit the PLC signal to the master module, and the slave module and the PLC signal received from the slave module Includes a PLC extension modem including a master module to communicate with the slave modem on the power line,
Two PLC extension modems are connected to each other via a distribution panel, and the PLC extension modem communicates through a neutral line of a power line.
In the first PLC extension modem located on one side of the distribution panel, a slave module communicating with a master modem located on one side of the distribution panel is connected via a signal line coupler connected to a signal line of the power line, and a master module is connected to a neutral line coupler connected to a neutral line of the power line. Connected through,
The second PLC extension modem located on the other side of the distribution panel is connected to a signal line coupler where a slave module is connected through a neutral line coupler connected to the neutral line of the power line, and a master module communicating with a slave modem located on the other side of the distribution panel is connected to the signal line of the power line. PLC system connected through delete According to claim 1, Neutral coupler,
PLC system characterized by being a non-contact coupler
The method of claim 3, wherein the PLC system,
A PLC system that forms a PLC network through a single power line network, but operates PLC signals for each group by changing PLC signals on one side and the other side around the distribution panel.
According to claim 4, PLC signal for each group,
PLC system characterized by different frequency bands
According to claim 5, PLC signal for each group,
A PLC system characterized by setting and grouping a network group ID in the header portion of the PLC signal packet.
The PLC extension modem of claim 6,
PLC system including setting unit for setting network group ID
The PLC extension modem of claim 7,
PLC system including group discrimination unit for determining network group ID
The PLC extension modem of claim 8,
PLC system including a signal processing unit that varies signal processing according to the network group ID set in the setting unit
The method of claim 9, wherein the signal processing unit is different from the signal processing,
PLC system characterized by generating a PLC signal by varying the frequency band according to the network group ID
The method of claim 9, wherein the signal processing unit is different from the signal processing,
A PLC system characterized by generating a network group ID differently in the header portion of the PLC signal packet.
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