JP2011205604A - Power line communication system and connection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power line communication system whose communication speed is improved and a connection device for improving the communication speed of power communication equipment.SOLUTION: An electric plug 21 is connected to an outlet 11, and power line communication equipment 20 is connected to an AC distribution network 40, and a power line 16 is connected via a capacitor 15 to a common conductor 13 (established antenna line, telephone line or the like) different from the AC distribution network 40, and the capacity of the capacitor 15 is set such that the high-frequency signal of the power line communication equipment 20 is selectively transmitted. Thus, it is possible to avoid the deterioration of a communication speed because of noise generated from an AC load such as illuminations 1 and 2 or fire alarms 3 and 4 as a source, and it is possible to improve the communication speed. Also, the common conductor 13 is configured of a core wire 13a and a shield 13b, and two power lines 16 are connected to the core wire 13a and the shield 13b so that a differential mode can be set.

Description

  The present invention relates to a power line communication system and a connection device, and is particularly useful when applied to power line communication in a building or the like in which an AC power distribution network is constructed.

  In recent years, power line communication is spreading mainly in general households (see, for example, Patent Document 1). Since power line communication uses an existing AC distribution network as a communication line, there is an advantage that a LAN can be constructed without newly performing communication wiring indoors. In particular, power line communication is a useful alternative in an environment where a sufficient communication speed cannot be obtained or cannot be communicated with a wireless LAN.

  The AC distribution network to which such power line communication is applied is connected to an AC load or a DC load via an AC adapter, but noise is riding on the AC distribution network from these AC load or AC adapter, It causes a decrease in the speed of power line communication.

  As a countermeasure against noise from an AC load or the like, there is a noise filter that can be additionally added to an insertion port of an electric plug (for example, see Patent Document 2).

  However, the AC load is not always connected to the AC power distribution network via the electric plug. For example, lighting, a fire alarm, a bathroom ventilation fan, and the like arranged on the ceiling are directly connected to the AC power distribution network without an electric plug. Since the speed of power line communication decreases due to noise from an AC load that is directly connected to such an AC power distribution network without going through an outlet, the application of a noise filter alone is not a perfect countermeasure.

JP 2008-236355 A JP 2009-206964 A

  This invention is made | formed in view of the said situation, and it aims at providing the connection apparatus which can improve the communication speed of the power line communication system and power communication apparatus which communication speed improved.

  A first aspect for achieving the above object is that an AC distribution network to which an AC load is connected, a plurality of power line communication devices connected to the AC distribution network, the power line communication devices are connected, and the power line The communication device includes a common conductor for transmitting a modulated high-frequency signal, the AC load is connected between the power line communication devices of the AC distribution network, and an AC load serving as a noise source is connected to the common conductor. The power line communication system is characterized in that a circuit for selectively transmitting the high-frequency signal is provided.

  In the first aspect, the situation in which the communication speed decreases due to noise caused by the AC load between the power line communication apparatuses connected to the AC distribution network is avoided, and the communication speed between the power line communication apparatuses is increased. Can be improved.

  According to a second aspect of the present invention, in the power line communication system according to the first aspect, the common conductor is a telephone network or an antenna line disposed indoors.

  In the second aspect, since the existing telephone network or antenna line can be used as the common conductor, the cost of providing a new common conductor can be reduced.

  According to a third aspect of the present invention, in the power line communication system according to the first or second aspect, the power line communication system includes two power lines that connect the AC distribution network and the AC load, and the common conductor includes two power lines. The power line communication system is characterized in that each power line is branched and connected to each conductor of the common conductor.

  In the third aspect, communication with each power communication apparatus is a communication mode in a differential mode using a common conductor composed of two conductors. For this reason, the loop area is reduced, and the influence of noise on the surroundings can be reduced.

  According to a fourth aspect of the present invention, in the power line communication system described in the first or second aspect, the power line communication system includes two power lines that connect the AC distribution network and the AC load, and one of the power lines is The power line communication system is connected to the common conductor.

  In this 4th aspect, since communication with each electric power communication apparatus should just use the common conductor which consists of one conductor, the wiring of a common conductor can be simplified.

  A fifth aspect of the present invention is a connection device that connects an AC distribution network to which an AC load is connected and a power line communication device, wherein the power line communication device is connected and connected to the AC distribution network. A first plug, a plurality of power line communication devices, a second plug connected to a common conductor that transmits a high-frequency signal modulated by the power line communication device, and a circuit that selectively transmits the high-frequency signal. And a power line between the first plug and the power line communication device is also connected to the second plug via the circuit.

  In the fifth aspect, a situation in which the communication speed is reduced due to noise caused by an AC load between the power line communication devices connected to the AC distribution network via the connection device is avoided. The communication speed can be improved.

  In addition, it is possible to improve the communication speed of the power line communication device simply by adding additional devices to the AC distribution network, so there is no need to install it in the AC distribution network itself. Can be realized.

  According to a sixth aspect of the present invention, in the connection device according to the fifth aspect, the power distribution unit includes two power lines that connect the AC distribution network and the AC load, and the common conductor is two conductors, Each of the power lines is branched and connected to each conductor of the common conductor.

  In the sixth aspect, communication with each power communication device is a communication mode in a differential mode using a common conductor composed of two conductors. For this reason, the loop area is reduced, and the influence of noise on the surroundings can be reduced.

  According to a seventh aspect of the present invention, in the connection device according to the fifth aspect, two power lines connecting the AC distribution network and the AC load are provided, and one of the power lines is the common conductor. It is in the connection apparatus characterized by being connected to.

  In the seventh aspect, since communication with each power communication device may use a common conductor made of one conductor, the wiring of the common conductor can be simplified.

  ADVANTAGE OF THE INVENTION According to this invention, the connection apparatus which can improve the communication speed of the power line communication system and power communication apparatus which improved communication speed is provided.

It is a block diagram of the house where the alternating current load is arrange | positioned. It is the schematic for demonstrating the connection apparatus which concerns on Embodiment 1 of this invention. It is a block diagram of an AC distribution network, a connection device connected thereto, an AC load, and the like. It is a graph showing the relationship between the capacity | capacitance of the capacitor | condenser provided in a common conductor, and communication speed. It is a block diagram of an AC distribution network according to a modification, a connection device connected thereto, an AC load, and the like. It is a figure which shows the circuit structure of the connection apparatus for demonstrating the connection form of a differential mode and a common mode. It is a schematic block diagram for demonstrating the aspect of a common conductor and a capacitor. It is a schematic block diagram of the connection apparatus which concerns on Embodiment 2 of this invention. It is a schematic block diagram of the connection apparatus which concerns on Embodiment 2 of this invention.

<Embodiment 1>
Based on FIG. 1, an AC distribution network which is a premise for using the connection device according to the present embodiment will be described. As shown in FIG. 1, an AC power distribution network 40 is disposed in a general house. The AC power distribution network 40 is a single-phase three-wire power line including a power line L1, a power line L2, and a neutral line N that are 180 degrees out of phase. The neutral line N is bifurcated and disposed on the first and second floors, the power line L1 is disposed on the first floor, and the power line L2 is disposed on the second floor. Moreover, although mentioned later for details, the common conductor 13 is arrange | positioned over the 1st floor and the 2nd floor. In the present embodiment, the common conductor 13 is an existing antenna line.

  On each floor of the house, lights 1 and 2 and fire alarms 3 and 4 which are examples of AC loads are installed and connected to the L1 line and the neutral line N, or the L2 line and the neutral line N, respectively. Each floor is provided with a connection device 10 (details will be described later) connected to the AC power distribution network 40, and a power line communication device 20 for performing power line communication is connected to the connection device 10. Yes. Each power line communication device 20 is connected with a personal computer 30 for transmitting and receiving data and a storage device (storage) 31 via a communication cable.

  The connection device 10 according to the present invention will be described in detail with reference to FIGS. FIG. 2 is a perspective view for explaining a schematic configuration of the connection device, and FIG. 3 is a configuration diagram of an AC power distribution network, a connection device connected thereto, an AC load, and the like.

  As shown in FIG. 2, the connection device 10 mediates connection between the power line communication device 20 and the AC power distribution network 40 (in the figure, the power lines L1, L2 and the neutral line N are integrally represented). Equipment. On the indoor wall, an outlet 52 for connecting to the AC power distribution network 40 and a terminal 50 for connecting to the common conductor 13 are provided.

  The connection device 10 includes a housing unit 12, and the housing unit 12 is provided with a first plug 53 connected to the outlet 52 and a second plug 51 connected to the terminal 50. The inside of the housing unit 12 is configured such that AC power is supplied from the AC power distribution network 40 to the power line communication device 20 via the outlet 52 and the first plug 53, and the power line communication device 20, the common conductor 13, and the like. A high frequency signal flows between the terminal 50 and the second plug 51.

  In such a connection device 10, the electric plug 21 of the power line communication device 20 is connected to the outlet 11, and the power line communication device 20 is connected to the personal computer 30 and the storage device 31 via the LAN interface 22 (RJ-45 or the like). Is connected.

  The power line communication device 20 modulates information of an information processing device such as the personal computer 30 and transmits the modulated signal superimposed on an AC power line, and a signal superimposed on the AC power line by another power line communication device 20. Is received and demodulated, and the demodulated signal is transmitted to the information processing device. Hereinafter, the signal superposed on the AC power line by the power line communication device 20 is referred to as a high frequency signal. In the power line communication apparatus 20 generally used, the frequency of the high frequency signal is about 2 to 30 MHz.

  The storage device 31 is a device that includes a storage medium and communication means, and records data from the personal computer 30 on the storage medium in response to a command received from the personal computer 30 via power line communication, or data from the recording medium. Is transmitted to the personal computer 30.

  Next, power line communication using the connection device 10 will be described with reference to FIG. As shown in the figure, the common conductor 13 is a transmission line that connects the power lines 16 in each connection device 10 and transmits a high-frequency signal of the power line communication device 20. In the present embodiment, a pair of the existing coaxial antenna wire core 13 a and the shield 13 b covering the core wire constitutes the common conductor 13. As another aspect of the common conductor 13, when a 6-pole 4-core telephone line (RJ-11) is already provided, the unused 2-core can be used as the common conductor. Naturally, an independent conductor is not limited to an existing antenna line or telephone line, and an independent conductor may be newly provided as a common conductor, and is not particularly limited as long as it can transmit a high-frequency signal. Note that when an antenna line is used, a signal such as a television broadcast (terrestrial digital broadcast: 470 to 710 MHz) transmitted to the antenna line is different from the frequency 2 to 30 MHz of the power line communication and can coexist.

  The outlet 11 of each connection device 10 is connected to the AC distribution network 40 by the power line 16. Specifically, one end of each of the two power lines 16 is connected to the neutral line N and the power line L1 (or the power line L2), and the other end is connected to the outlet 11. Each of the two power lines 16 branches in the middle and is connected to the core wire 13 a and the shield 13 b of the common conductor 13 via the capacitor 15.

  The capacitor 15 is an example of a circuit that cuts off AC power and selectively transmits a high-frequency signal. By connecting the power line 16 to the common conductor 13 via the capacitor 15, a high-frequency signal from the power line communication device is selectively transmitted to the common conductor 13.

  According to such a connection device 10, with respect to power, AC power is supplied from the AC distribution network 40 to the power line communication device 20 in which the electrical plug 21 is connected to the outlet 11.

  On the other hand, regarding the signal, in the connection device 10, the common conductor 13 serves as a signal transmission path, and communication between the power line communication devices 20 is possible. Taking the communication between the personal computer 30 and the storage device 31 as an example, the high-frequency signal modulated by the power line communication device 20 to superimpose the data received from the personal computer 30 on the AC power line 16 is the electrical plug 21. And it is transmitted to the electric power line 16 through the outlet 11 connected to this. At this time, the AC power of 50-60 Hz in the power line 16 of each connection device 10 is cut off by the capacitor 15, and the high-frequency signal passes through the capacitor 15 and is transmitted to the common conductor 13. The high-frequency signal transmitted to the common conductor 13 passes through the capacitor 15 of the other connection device 10 and is transmitted to the other power line communication device 20 through the power line 16 and demodulated, and the storage device 31 is demodulated. Receive data.

  Moreover, the illumination 2 is connected between the power line communication devices 20 in the AC distribution network 40. As described above, when the lighting 2, that is, the noise source is present between the power line communication devices 20 of the AC distribution network 40, if power line communication is performed using the AC distribution network 40 without using the common conductor 13, the power line communication is performed. The S / N ratio between the signal transmitted from one of the devices 20 to the other and the noise from the illumination 2 deteriorates, and the communication speed decreases.

  However, in the present embodiment, the AC distribution network 40 includes noise generated by the lights 1 and 2 and the fire alarms 3 and 4, but the common conductor 13 has no noise source. That is, the high-frequency signal can be transmitted to another connection device 10 via the common conductor 13 in which no noise source exists. As a result, a decrease in communication speed due to the influence of noise can be avoided, and power line communication with improved communication speed can be performed.

  Moreover, since the existing antenna line is used as the common conductor 13, the cost of providing a new common conductor can be reduced.

Here, the relationship between the capacity of the capacitor 15 and the communication speed between the personal computers 30 will be described. FIG. 4 is a graph showing the relationship between the capacitance of the capacitor and the communication speed between personal computers connected to the power line communication device. When the capacitance of the capacitor 15 is 1 to 10 ² pF, the communication speed gradually increases to 0 to 30 Mbps, and between 10 ² to 10 ⁵ pF, it is constant at approximately 30 Mbps. When the capacitance is 10 ⁶ pF or more, there is a possibility that abnormal noise may be generated from the capacitor 15 or a failure may occur.

  The capacitance of the capacitor 15 here refers to the capacitance of the capacitor 15 disposed between the common conductor 13 and each power line communication device 20 (power line 16). In the present embodiment, the capacitance of each capacitor 15 is 100 pF. In this case, according to the graph, each personal computer 30 and the storage device 31 can perform data communication at 30 Mbps, which is a communication speed corresponding to 100 pF.

  As described above, in the connection device 10 according to the present invention, the common conductor 13 is used as a signal transmission path, and the capacitor 15 that selectively transmits a high-frequency signal is provided. Thereby, between the power line communication devices 20 connected to the AC power distribution network 40, a situation in which the communication speed is reduced due to noise caused by an AC load such as the lights 1, 2 and the fire alarms 3, 4 is generated. It can avoid and the communication speed between the power line communication apparatuses 20 can be improved.

  In addition, since the communication speed of the power line communication device 20 can be improved only by additionally adding the connection device 10 to the AC power distribution network 40, the existing power line communication device 20 can be used as it is, and a new communication device can be used. This eliminates the need for building a LAN by introducing.

  Furthermore, in the connection device 10 according to the present embodiment, it is not necessary to connect the common conductor 13 for every combination in which two of the three (or three or more) power line communication devices 20 are one set. That is, since only one common conductor 13 has to be provided, it is possible to reduce the labor and cost associated with the laying of the common conductor 13.

  Here, in the connection device 10 according to the above-described embodiment, each of the two power lines 16 is connected to the pair of common conductors 13 of the core wire 13a and the shield 13b via the capacitor 15. It is not limited to the form, and any one of the two power lines 16 may be connected to the common conductor 13.

  FIG. 5 is a configuration diagram of an AC distribution network, a connection device connected thereto, an AC load, and the like according to a modification. In addition, the same code | symbol is attached | subjected to the same thing as FIGS. 1-3, and the overlapping description is abbreviate | omitted. As illustrated, the connection device 10 includes two power lines 16 that connect the AC power distribution network 40 and the outlet 11. One of the two power lines 16 is connected to the core wire 13 a constituting the common conductor 13 via the capacitor 15.

  Also in the connection form between the common conductor 13 and the connection device 10, the common conductor 13 serves as a signal transmission path, and communication between the power line communication devices 20 is possible. That is, the high frequency signal transmitted from the power line communication device 20 is transmitted to the power line 16 through the electric plug 21 and the outlet 11 connected thereto, and the high frequency signal is transmitted to the common conductor 13 through the capacitor 15. The high-frequency signal transmitted to the common conductor 13 passes through the capacitor 15 of the other connection device 10 and is transmitted to the other power line communication device 20 via the power line 16.

  Here, (A) a connection device 10 (see FIG. 3) in which two power lines 16 are connected to a pair of common conductors 13 via capacitors 15 respectively, and (B) a pair of two common conductors 13 A connection form with the connection device 10 (see FIG. 5) in which one of the two power lines 16 is connected to the common conductor 13 via the capacitor 15 will be described. 6A shows a circuit configuration of the connection device 10 in FIG. 6A, and FIG. 6B shows a circuit configuration of the connection device 10 in FIG.

  As shown in FIG. 6A, the power line 16 is connected to both the core wire 13 a and the shield 13 b which are the two conductors constituting the common conductor 13 via the capacitor 15. That is, the two core wires 13a and the shield 13b are used as a high-frequency signal transmission path. In this case, communication between the connection devices 10 is performed in a differential mode in which one core wire 13a (or shield 13b) serves as a signal forward path and the other shield 13b (or core wire 13a) serves as a signal return path (signal ground). It will be.

  On the other hand, as shown in FIG. 6B, one of the two power lines 16 is connected to the core wire 13 a that is one of the two conductors forming the common conductor 13 via the capacitor 15. In this case, the communication between the connection devices 10 is performed in the common mode in which the core wire 13a is a signal outgoing path, and the ground 17 connected via the neutral line N or the stray capacitance 18 of the AC distribution network 40 is the signal return path. It will be.

  Although the power line communication devices 20 can communicate with each other in any of the differential mode and common mode communication modes, from the viewpoint of noise, the differential mode, that is, the common conductor 13 as shown in FIG. It is preferable to use the connection device 10 in which the power line 16 is connected to both of the two core wires 13a and the shield 13b that form the above via the capacitor 15. In the differential mode, a closed circuit composed of the core wire 13a and the shield 13b is formed. However, the closed circuit has a smaller loop area than the closed circuit composed of the core wire 13a, the neutral wire N, and the ground 17 in the common mode. This is because the noise generated from the closed circuit in the mode is smaller than the noise generated from the closed circuit in the common mode.

  Therefore, the differential mode connection device 10 can reduce the influence of noise as compared with the common mode, and the common mode connection device 10 has an advantage that the wiring can be further simplified.

<Embodiment 2>
The connection device 10 according to the present invention is not limited to the configuration described in the first embodiment. Various configurations of the common conductor and the capacitor that can be employed as the connection device will be described.

  FIG. 7 is a schematic configuration diagram for explaining aspects of the common conductor and the capacitor. As shown in the figure, one capacitor 15 is provided for each connection device with the common conductor 13 as the center, and a communication speed of 30 Mbps can be realized by setting each capacitance to 100 pF (see FIG. 4). However, the stray capacitance not shown is also set to 100 pF.

  At this time, as shown in FIG. 7B, when paying attention to the two connection devices 10, the common conductor 13 is disposed between the two capacitors 15. As shown in FIG. 7C, the two capacitors 15 connected in series are electrically equivalent to one capacitor 15 having these two combined capacitances. In this case, it can be considered that the common conductor 13 is embedded in the capacitor 15. That is, as illustrated in FIG. 7C, the common conductor 13 may be included in the capacitor 15.

  A connection device in which such a common conductor 13 is included in a capacitor 15 is shown.

  FIG. 8 is a configuration diagram of a connection device in which the common conductor is included in the capacitor. As shown in the figure, in each connection device 10, the power lines 16 are connected by a capacitor 15A. As shown in FIG. 7C, the common conductor 13 is included in the capacitor 15A.

In the first embodiment, the capacitance of the capacitor 15 disposed between the common conductor 13 and each connection device 10 is 100 pF. In this embodiment, the capacitance of the capacitor 15A is such two capacitors. 15 corresponds to the synthesized one. That is, by setting the capacitance of the capacitor 15A to 50 pF (1/100 [pF ⁻¹ ] +1/100 [pF ⁻¹ ] = 50 [pF ⁻¹ ]), the 100 pF capacitor 15 of the first embodiment was used. As in the case, a communication speed of 30 Mbps can be realized without being affected by noise from the lights 1 and 2 and the fire alarms 3 and 4.

  In each connection device 10 shown in FIG. 8, one of the two power lines 16 is connected to another connection device 10 via a capacitor 15A (common conductor 13). That is, a closed circuit including the single power line 16, the capacitor 15A (common conductor 13), and the ground line N (not shown) connected by the neutral line N or the stray capacitance of the AC distribution network 40 is formed. The communication mode is common mode.

  FIG. 9 is a configuration diagram of a connection device using two capacitors in which the common conductor is included in the capacitor. As shown in the figure, each of the two capacitors 15 </ b> B connects the power lines 16 of the connection devices 10. The capacitance of the capacitor 15B is 50 pF. In this case, one of the two capacitors 15B has a combined capacitance of 100 pF. Therefore, in the connection device 10 shown in the figure, communication between the personal computers 30 is performed at a communication speed of 30 Mbps (see FIG. 4) without being affected by noise from the lights 1, 2 and the fire alarms 3, 4. It can be performed.

  In each connection device 10 shown in FIG. 9, each of the two power lines 16 is connected to another connection device 10 via a capacitor 15B (common conductor 13). That is, a closed circuit composed of the two power lines 16 and the capacitor 15B (common conductor 13) is formed, and a communication mode in the differential mode is obtained.

  Moreover, in Embodiment 1 and Embodiment 2 demonstrated above, although the connection apparatus 10 provided with the common conductor 13 and the capacitors 15, 15A, 15B was used, it is not restricted to such a case. In other words, each power line communication device 20 may be connected to the common conductor 13 via the capacitor 15.

  For example, the capacitor 15 is disposed in the casing 12 of the connection device 10, but the physical placement location is not particularly limited as long as it is provided in the common conductor 13. That is, the overall configuration includes an AC power distribution network 40, a power line communication device 20 connected to the AC power distribution network 40, and a common conductor 13 that connects each power line communication device 20, and the common conductor 13 is connected via the capacitor 15. As long as it is connected to the power line communication device.

  According to the power line communication system having such a configuration, an AC load such as the illuminations 1 and 2 and the fire alarms 3 and 4 is used as a generation source between the power line communication devices 20 connected to the AC distribution network 40. A situation in which the communication speed is reduced due to noise can be avoided, and the communication speed between the power line communication devices 20 can be improved.

  INDUSTRIAL APPLICABILITY The present invention can be used in an industrial field that provides power line communication in a facility where an AC power distribution network is laid.

L1, L2 Power line N Neutral line 1, 2 Lighting 3, 4 Fire alarm 10 Connection device 11, 52 Outlet 12 Housing part 13 Common conductor 15, 15A, 15B Capacitor 16 Power line 17 Ground 18 Floating capacitance 20 Power line communication device 21 Electrical plug 22 Interface 30 Personal computer 31 Storage device 40 AC power distribution network 50 Terminal 51 Second plug 53 First plug

Claims (7)

An AC distribution network to which an AC load is connected;
A plurality of power line communication devices connected to the AC distribution network;
Connecting each of the power line communication devices, a common conductor for transmitting a high frequency signal modulated by the power line communication device,
The AC load is connected between the power line communication devices of the AC distribution network,
An AC load that is a noise source is not connected to the common conductor, and a circuit that selectively transmits the high-frequency signal is provided. In the power line communication system according to claim 1,
The power line communication system, wherein the common conductor is a telephone network or an antenna line disposed indoors. In the power line communication system according to claim 1 or 2,
Two power lines connecting the AC distribution network and the AC load,
The common conductor is two conductors,
Each power line is branched and connected to each conductor of the common conductor, respectively. In the power line communication system according to claim 1 or 2,
Two power lines connecting the AC distribution network and the AC load,
A power line communication system, wherein one of the power lines is connected to the common conductor. A connection device that connects an AC distribution network to which an AC load is connected and a power line communication device,
A first plug to which the power line communication device is connected and connected to the AC distribution network;
A second plug connected to a common conductor for connecting a plurality of power line communication devices and transmitting a high frequency signal modulated by the power line communication device;
A circuit for selectively transmitting the high-frequency signal,
A power line between the first plug and the power line communication device is also connected to the second plug via the circuit. The connection device according to claim 5,
Two power lines connecting the AC distribution network and the AC load,
The common conductor is two conductors,
Each of the power lines is branched and connected to each conductor of the common conductor. The connection device according to claim 5,
Two power lines connecting the AC distribution network and the AC load,
One of the power lines is connected to the common conductor.

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