JP3368393B2 - Power line carrier communication system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power line carrier communication system mainly for performing centralized control / management of housing equipment and the like, using a power line as a communication medium.

[0002]

2. Description of the Related Art In recent years, for example, in home automation, each branch power line branched from a power line through a branching filter is used as a communication medium (signal transmission path).
On this branch power line, an adapter that controls loads such as lighting, a controller that sends a high-frequency remote control signal to this adapter, or an intercom master unit / slave unit that modulates the high-frequency signal with voice and connects Power line carrier communication systems are used. The branching filter is a filter for preventing the communication signal on the branching power line from leaking to the outside through the power line, and for example, a low pass filter can be used.

In the conventional power line carrier communication system as described above, there are a plurality of branch power lines as signal transmission lines in the system, and when independent communication is performed for each branch power line, they are connected to different branch power lines respectively. There was a problem that interference occurred between the power line carrier communication devices. For example, when a remote operation signal is transmitted from a controller connected to one branch power line A to a designated adapter, the transmission signal is induced to a conductor in the vicinity of the branch power line A, and another conductor is further branched from this adjacent conductor. There is a crosstalk problem between the branch power lines that is guided to the power line B and causes an unspecified adapter connected to the other branch power line B to operate.

As a conventional known document for solving the interference problem in the power line carrier communication system, for example, Japanese Patent Laid-Open No. Hei 4-
There is one disclosed in Japanese Patent No. 192727. FIG. 14 is a configuration diagram of a conventional power line carrier communication system shown in the above-mentioned document. In the figure, 1 is a commercial power source, 2 is a main power line, 23a and 23b are controllers, 24 is a close conductor,
25a and 25b are low impedance elements, 26a and 26
b is a low-pass filter, 27a and 27b are branch power lines, and each has two electric wires 27a1 and 27a2 and 27b.
1 and 27b2.

In the system shown in FIG. 14, branch power lines 27a and 27b are branch-connected from the main power line 2 via low-pass filters 26a and 26b, respectively.
The controller 23a is connected to the transmission path of a and the controller 23b is connected to the transmission path of the branch power line 27b. Further, low impedance elements 25a and 25b are connected between one of the two electric wires of the main power line 2 connected to the low-pass filters 26a and 26b and the adjacent conductor 24, respectively.

The operation of FIG. 14 will be described. If the signal of the controller 23a now leaks from the branch power line 27a to the proximity conductor 24, the closed loop indicated by the broken line in the figure returns to the controller 23a from the proximity conductor 24 via the low impedance element 25a and the low pass filter 26a. Since it is formed, leakage to the other branch power line 27b does not occur.

[0007]

The conventional power line carrier communication system is constructed as described above, and is described in the above-mentioned Japanese Patent Laid-Open No.
In the case of Japanese Patent Laid-Open No. 192727/1997, although a low impedance element is designed to absorb the influence of leakage that occurs through the proximity conductor, the branch power line 27 seen from the proximity conductor is used.
Since the impedance of a is significantly different between the power lines 27a1 and 27a2, there is a problem that the common mode noise on the transmission line from the adjacent conductor and the normal mode noise on the transmission line are at substantially the same level. In addition, due to the above problem, the branch power line 27a
There is a problem that a signal is easily induced directly when the wiring of No. 27 and the wiring of No. 27b are close to each other.

The present invention has been made to solve the above problems, and in power line communication, it reduces leakage from a nearby conductor and suppresses the influence of common mode noise on normal mode noise. It is an object of the present invention to obtain a power line carrier communication system capable of preventing interference between branch power lines.

[0009]

A power line carrier communication system according to claim 1 of the present invention is respectively coupled to each branch power line branched from a main power line through a branch filter, and each branch power line is used as a communication medium. In a power line carrier communication system including a power line carrier communication device for respectively communicating, two impedances looking inward from respective output ends of the branch filter to which two electric wires of each branch power line are respectively connected are balanced, and A branch filter configured to have a high impedance with respect to a communication signal from the power line carrier communication device, and one of two wires of a main power line connected to each branch filter and a ground wire. And a high-pass filter connected between the two.

According to a second aspect of the present invention, there is provided a power line communication system, wherein each power line is branched from a main power line via a block filter.
A controller that transmits a remote control signal, an adapter that receives a signal from the controller to perform load control, or an intercom base unit / slave unit that performs a call using a voice modulation signal using each of the branch power lines as a communication medium In a power line carrier communication system including a power line carrier communication device, two impedances looking inward from respective output ends of the block filter to which the two electric wires of the respective branch power lines are respectively connected are balanced, and the power line carrier communication A block filter configured to have a high impedance with respect to a communication signal from a device and a low impedance with respect to a signal other than the communication signal, and two electric wires of a main power line connected to each block filter. Equipped with a high-pass filter connected between one of the wires and the ground wire. Those were.

A power line carrier communication system according to a third aspect of the present invention is the power line carrier communication system according to the second aspect, wherein the block filter has a pair of input terminals to which a main power line and a branch power line are respectively connected and an output. It has a configuration including a pair of parallel resonant circuits provided between the ends for each electric wire and a series resonant circuit provided between a pair of input ends to which the main power line is connected.

A power line carrier communication system according to a fourth aspect of the present invention is the power line carrier system according to any of the first to third aspects, wherein the branch filter or the block filter is connected to the main power line of the filter. The high-pass filter in which one of the two terminals is connected in advance to one of the two terminals is housed in the same housing.

A power line carrier communication system according to a fifth aspect of the present invention is the power line carrier communication system according to any one of the first to fourth aspects, wherein each branch power line has two wirings. The wiring has a wiring structure in which the wiring and the wiring of the grounding wire are three wirings in close proximity to each other, and the grounding wire is connected to a grounding terminal via a low-pass filter.

A power line carrier communication system according to a sixth aspect of the present invention is the power line carrier communication system according to the fifth aspect, wherein the low-pass filter and the branch filter or block filter are housed in the same housing. It has a different structure.

A power line carrier communication system according to a seventh aspect of the present invention is the power line carrier communication system according to any one of the first to third aspects, wherein the impedance characteristic of the high-pass filter is variable, so The configuration is such that a plurality of high-pass filters having different characteristics and a selection switch for selectively connecting one of the plurality of high-pass filters are provided.

The power line carrier communication system according to claim 8 of the present invention is the power line carrier communication system according to claim 5 or 6, wherein the power line carrier communication system is connected between each wire of each branch power line and a ground wire. , Each power of each branch power line
The impedance between the line and the ground line is
It is provided with a low impedance element for lowering the impedance than the impedance.

[0017]

[0018]

[0019]

In the invention according to claim 1, a power line carrier communication device is included, which is coupled to each branch power line branched from the main power line through a branch filter and performs communication using each branch power line as a communication medium. In the power line carrier communication system, the branch filter balances two impedances inwardly seen from each output end of the branch filter to which two wires of each branch power line are connected, respectively, and the power line carrier communication device Is configured to have a high impedance for a communication signal. The high-pass filter is connected between one of the two electric wires of the main power line connected to each of the branch filters and the ground line.

According to another aspect of the present invention, there is provided a controller which is coupled to each branch power line branched from the main power line through a block filter, and which transmits a remote control signal using each branch power line as a communication medium. In a power line carrier communication system including a power line carrier communication device such as an adapter that receives a signal from the controller and performs load control, or an intercom master unit / slave unit that performs a call using a voice modulation signal, the block filter includes: The two impedances inwardly seen from the respective output ends of the block filter to which the two electric wires of the respective branch power lines are respectively connected are balanced, and the impedance is high for a communication signal from the power line carrier communication device. It has low impedance for signals other than communication signals. Configured. The high-pass filter is connected between one of the two electric wires of the main power line connected to each of the block filters and the ground line.

In the invention according to claim 3, in the invention according to claim 2, the block filter is provided for each electric wire between a pair of input end and output end to which a main power line and a branch power line are respectively connected. And a series resonance circuit provided between a pair of input terminals to which the main power line is connected.

In the invention according to claim 4, in the invention according to any one of claims 1 to 3, any one of the branch filter or the block filter and the two terminals to which the main power line of the filter is connected A high-pass filter in which one terminal is connected to the other terminal in advance is housed in the same housing.

In the invention according to claim 5, in the invention according to any one of claims 1 to 4, the wiring of each branch power line includes two wirings of the power line and a ground line. Is connected by three wires, and the ground wire is a wire connected to a ground terminal via a low-pass filter.

In the invention according to claim 6, in the invention according to claim 5, the low-pass filter and the branch filter or block filter are housed in the same housing.

According to a seventh aspect of the present invention, in the invention according to any one of the first to third aspects, one of a plurality of high pass filters having different impedance characteristics and one of the plurality of high pass filters are provided. The impedance characteristic of the high-pass filter is made variable by the configuration provided with a selection switch for selectively connecting.

In the invention according to claim 8, in the invention according to claim 5 or 6, low-impedance elements connected respectively between the electric wires of the branch power lines and the ground line are provided. .

[0027]

[0028]

[0029]

【Example】

Embodiment 1 Hereinafter, each embodiment of the present invention will be described with reference to the drawings. First Embodiment FIG. 1 is a configuration diagram of a power line carrier communication system showing a first embodiment of the present invention. In FIG.
Is a main power line, and 3a and 3b are block filters (band stop filters). The block filter is a filter that blocks signals in a predetermined band of the input signal and blocks signals in other bands. In this embodiment, a high frequency communication signal on the side of the branch power line (for example, a predetermined band centered on 125 kHz). Signal) is blocked from passing to the main power line side.

Reference numerals 4a and 4b denote branch power lines, each of which is composed of two electric wires 4a1 and 4a2, 4b1 and 4b2, respectively, from the main power line 2 to a block filter 3a, respectively.
It is a power line branched via 3b. Reference numerals 5a and 5b are terminals connected to the transmission lines of the branch power lines 4a and 4b, and 7a and 7b are ground lines (ground lines) wired to the branch power lines 4a and 4b, respectively, and one ends of which are ground terminals. 6 is connected. Reference numerals 8a and 8b denote high-pass filters installed corresponding to the block filters 3a and 3b, respectively, and one of the two electric wires of the main power line 2 connected to the block filters 3a and 3b and the ground wire 7a, 7b is connected.

FIG. 2 is a diagram showing an example of the configuration of the block filter 3 in FIG. 1. The branch power is transmitted from the main power line 2 side to each branch power line 4 side, and from the branch power line 4 side to the main power line 2 side. Of the high frequency communication signal is blocked. Therefore, in the block filter 3 of FIG. 2, a pair of parallel resonant circuits 9 is provided for each electric wire between a pair of input ends and output ends to which the main power line 2 and the branch power line 4 are connected, respectively, and a pair of parallel resonant circuits 9 is provided for a communication signal. A high impedance is provided between the input and output ends, and a series resonant circuit 17 is provided between a pair of input ends to which the main power line 2 is connected so that the input end has a low impedance with respect to a communication signal. There is. With the above configuration, the block filter 3 has a steep pass blocking characteristic with respect to the frequency band of the high frequency communication signal.

As a result of constructing the block filter 3 as described above, from the two impedances viewed from the respective output ends of the block filter 3 to which the two electric wires of the respective branch electric wires 4 are respectively connected, that is, from the electric wire 4a1. The impedance of the inside of the block filter 3a and the impedance of the inside of the block filter 3a similarly seen from the electric wire 4a2 are balanced (balanced), and since this balanced impedance is a high impedance for the communication signal, Leakage from the branch power line 4 side to the main power line 2 side can be suppressed to an extremely small level. Due to the balanced configuration of the block filter 3, the impedance of the branch power line 4a1 seen from the ground line 7a,
The impedance of the branch power line 4a2 is almost equal.

FIG. 3 is a diagram showing an example of the configuration of the high-pass filter 8 in FIG. 1, whose input end and output end are connected to the main power line 2 and the ground line 7, respectively, and the distribution board ( It is connected to a ground terminal 6 provided on (not shown) or the like.

FIG. 4 is a system configuration diagram for comparison, which is configured to have a system configuration equivalent to that of FIG. 1 by using the low impedance element 25 and the low pass filter 26 in FIG. Next, in the power line carrier system configured as described above, a method of reducing the influence of a signal leaking on the branch power line 4a and affecting the other branch power line 4b will be described with reference to FIGS. The difference between the system configuration of the first embodiment and the configuration according to the conventional method of FIG. 4 will be mainly described.

Now, when the terminal 5a transmits a high frequency communication signal, the two electric wires 4a1 and 4a on the branch power line 4a are
A normal mode voltage having a reversed phase is generated during a2. A voltage is induced by capacitive coupling from the two electric wires 4a1 and 4a2 to the ground wire 7 which is a close conductor. Here, in the case of the configuration of FIG. 1, the impedances of the branch power lines 4a1 and 4a2 seen from the ground line 7 are substantially equal because of the balanced configuration of the block filter 3, and the level of the induced voltage is also equal. It comes to cancel each other out. However, in the case of the configuration of FIG. 4, the impedances of the branch power lines 4a1 and 4a2 seen from the ground line 7 are induced in the ground line 7 because the internal impedance of the low-pass filter 26 is different between the 4a1 side and the 4a2 side. The voltage level will vary. As a result, the induced voltage difference is generated on the ground wire 7.

By the way, since one of the main power lines 2 has a potential difference from the ground terminal 6 due to the form of the commercial power source 1, the impedance of the branch power line 4a as seen from the ground line 7 is very high. . Therefore, the level of the voltage induced in the ground wire 7 tends to be high,
Even if the distance between the ground line 7 and the branch power lines 4a1 and 4a2 is slightly different, the difference in impedance due to the difference in capacitance component becomes large.

[0037] Therefore, by connecting the high-pass filter 8 between the ground wire 7 and main electric power line 2, lower Then together the ground wire 7 viewed from the impedance of the entire branch power line 4a
The impedance between the branch power line 4a1 and the ground line 7a.
In between the dance and branch power line 4a2 and the ground line 7a
High-pass filter because the difference from the impedance is small.
Compared to the case without the branch power line 4a1 and the branch power line
4a2 and the voltage induced by both become small,
As a result, from the branch power line 4a1 and the branch power line 4a2
Leakage signal on the ground wire caused by the difference in induced voltage
The number can be reduced. In this way, the configuration of FIG.
By adopting this, leakage from the branch power line 4a to the ground line 7
Leakage signal on the ground wire 7 while reducing the leakage level
Can be reduced.

Embodiment 2 FIG. 5 is a block diagram of a block filter showing Embodiment 2 of the present invention. Reference numeral 28 in FIG. 1 is a block when the high pass filter 8 in FIG. 1 is housed in the housing of the block filter 3. An example of a filter is shown. With such a configuration, the effect of the first embodiment described above can be obtained without separately connecting the high-pass filter on the main power line 2, and the workability of the construction can be improved.

[Embodiment 3] FIG. 6 is a block diagram of a power line carrier communication system showing Embodiment 3 of the present invention. In the figure, reference numeral 10 is a three wire including two wires of a ground wire 7 and a branch power line 4. It is a cable. Further, 11 is a low-pass filter inserted between the ground wire 7 and the ground terminal 6. The other configuration of FIG. 6 is the same as that of FIG. In the first embodiment of FIG. 1, as described above, the branch power line 4 of the block filter 3a.
a1 and 4a2 have the same impedance, and a high-pass filter 8 is provided between the main power line 2 and the ground line 7a.
Although the impedance of the branch power line 4a as viewed from the ground line 7a is lowered by inserting a, the leakage voltage is somewhat generated in the ground line 7a due to the positional relationship between the ground line 7a and the branch power lines 4a1 and 4a2. I will end up.

The potential generated on the ground wire 7a does not affect the ground wire 7b of the other branch power line 4b as long as the ground resistance at the ground terminal 6 is very small, but the ground resistance is generally several tens. Since there is Ω, the signal generated on the ground plane by the ground line 7a directly affects the ground line 7b. Therefore, in the third embodiment of FIG. 6, two wirings of the branch power line 4 and the wiring of the ground wire 7 are wired by three wires close to each other, and the wiring between each ground wire 7a, 7b and the ground terminal 6 is performed. By inserting the low-pass filters 11a and 11b into the ground line 7 respectively, leakage from the ground line 7 to the ground terminal 6 is reduced, and the leakage voltage generated from the branch power line 4a to the ground line 7a is the ground line of the other branch power line 4b. 7b can be suppressed. That is, it is possible to reduce the influence of the leakage voltage generated from one branch power line 4a on the other branch power line 4b and reduce the adverse effect between the branch power lines.

Embodiment 4 FIG. 7 is a block diagram showing the construction of Embodiment 4 of the present invention. Reference numeral 12 in FIG. 7 is a block when the low-pass filter 11 in FIG. 6 is housed in the housing of the block filter 3. An example of a filter is shown. With such a configuration, it is not necessary to provide a space for grounding the low-pass filter in the distribution board or the like, and the connecting portion can be provided in one housing, so that workability of construction can be improved.

Embodiment 5 FIG. 8 is a block diagram of a power line carrier communication system showing Embodiment 5 of the present invention. In FIG. 8, reference numeral 13 denotes a plurality of high-pass filters 8 having different impedance characteristics shown in FIG. 1, and one of the plurality of high-pass filters.
It is a high-pass filter with a variable characteristic in which a selection switch 14 for selectively connecting two is internally provided. Connected to 7. Therefore, the impedance characteristic of the high pass filter 13 can be selected by switching the connection position of the selection switch 14. Further, reference numeral 15 is an earth leakage breaker for shutting off the circuit between the input and the output for ensuring safety when detecting that the current on the main power line 2 is leaking to the earth line 7 or the like.

As already described with reference to FIG. 1, by inserting the high-pass filter 8, the impedance of the branch power line 4 viewed from the ground line 7 can be lowered to reduce the leakage voltage level. Depending on the characteristics, the earth leakage breaker 15 may operate. Therefore, in the high-pass filter 13 having a variable characteristic shown in FIG. 8, the built-in selection switch 14 is used to switch to the high-pass filter 8 having a different characteristic. 8 is selected, and the leakage voltage level can be reduced without operating the earth leakage breaker 15.

Sixth Embodiment FIG. 9 is a block diagram of a power line carrier communication system showing a sixth embodiment of the present invention. 16 in the figure is connected between each of the electric wires 4a1 and 4a2 of the branch power line 4a and the ground wire 7, respectively. Low impedance device. As described in the description of the first embodiment, when the impedance between the ground line 7 and the branch power line 4a is high, the leakage voltage is easily induced. However, as described in the description of the third embodiment, if the impedance between the ground line 7a and the branch power line 4a is lowered, the ground line 7a is reduced.
If a leak occurs on a, it will affect the other ground wire 7b.

Therefore, as in the third embodiment, the low-pass filter 11a reduces the influence of the ground line 7a on other ground lines, and in the sixth embodiment of FIG. 9, the two low impedance elements 16 are connected to the branch power line. Each electric wire 4a of 4a
It is possible to further reduce the leakage voltage level by connecting between 1, 4a2 and the ground wire 7a and lowering the impedance between them. Therefore, even if a low level leakage voltage is generated on the ground wire 7a, the influence on the other ground wire 7b can be suppressed to a small level.

Seventh Embodiment FIG. 10 is a block diagram of a power line carrier communication system showing a seventh embodiment of the present invention, in which 18 is a branch power line 4a1 and 4a.
It is a limit circuit connected to a2 for absorbing a signal component having a predetermined voltage value or more. FIG. 11 is a diagram showing one configuration example of the limit circuit 18 in FIG.
One capacitor and a varistor in the middle of the capacitor (a pair of Zener diodes may be connected to each other in series) are connected in series, and a signal component having a voltage value equal to or higher than a preset voltage value can be absorbed.

FIG. 12 is a diagram showing an example of the wiring form when the lighting control system is realized by the power line carrier communication system of the present invention, and shows an example of the wiring form on the branch power line of an actual device. . In the figure, 5 and 5'are terminals, 18 is a limit circuit, 19 is a controller, 20
Is installed on a wall by an operation switch. Reference numeral 21 denotes a lighting fixture, and each lighting fixture 21 is connected to the branch power line 4 via terminals 5 and 5'and installed on the ceiling or the like. A distribution board 29 is provided with the block filter 3 and the controller 19 inside.

The seventh embodiment will be described with reference to FIGS. When the terminal 5a of FIG. 10 transmits, the voltage value of the signal generated on the branch power line 4a depends on the impedance of the branch power line 4a. The level of leakage that occurs is generally proportional to the voltage value that occurs. Therefore, if the impedance of the branch power line 4a is lowered in order to reduce the voltage value of the signal for the purpose of reducing leakage, loss may occur due to the wiring and the signal may not be transmitted.
By the way, when the wiring of an actual device is considered as shown in FIG. 12, the block filter 3 and the controller 19 are connected to the inside of the distribution board 29 or the like, and the switch 2 for operation is used.
0, the terminal 5 for controlling the lighting fixture 21, and the like are connected to a relatively large place.

In such a wiring configuration, when the controller 19 transmits, a large voltage is generated on the output side of the controller 19 because the impedance of the branch power line 4a viewed from the controller 19 is high, but this excessive voltage is a limit circuit. After being absorbed by 18 and dropped to an appropriate voltage, it is further attenuated by a voltage drop generated in the process of transmitting the wiring and transmitted to the target terminal 5, so that the level of leakage can be reduced. If the terminal 5'transmits, the terminal 5 '
Since a large number of other terminals 5 are installed in the vicinity of, the impedance of the branch power line 4a is low, and therefore transmission is performed with a relatively small voltage. However, in this case, the limit circuit 1
Since it is not absorbed by 8, the voltage can be transmitted to the target terminal 5 with a voltage drop only due to the attenuation by the wiring.

Eighth Embodiment FIG. 13 is a block diagram showing the configuration of an eighth embodiment of the present invention. Reference numeral 22 in FIG. 12 is a block when the limit circuit 18 in FIG. 12 is housed in the housing of the block filter 3. An example of a filter is shown. As a result of the configuration shown in FIG. 13, in the general wiring configuration described in FIG. 12, the controller 19 and the terminal 5 are rarely installed near the wiring position of the block filter 3,
Since the impedance of the power branch line 4 is high, the limit circuit 18 is installed at the location of this high impedance, the overvoltage absorption effect is increased, and it is necessary to provide a space for installing the limit circuit 18 on the branch power line 4a. Further, since no special wiring work is required when installing the limit circuit 18, the workability of the work can be improved.

In the above embodiment, the main power line 2
Although a block filter (band stop filter) 3 is used as a branch filter for branching from each branch power line 4 to each branch power line 4, the branch filter of the present invention is not limited to this block filter 3. The branch filter of the present invention has a pair of input end and output end to which a main power line and a branch power line each consisting of two electric wires are connected, and a branch filter of the branch power line to which the two electric wires are respectively connected. It suffices that the two impedances looking inward from the respective output terminals are balanced and that the impedance is high for a communication signal from the power line carrier communication device. For example, it may be a low-pass filter in which two impedances looking inward from each output end have a balanced configuration.

[0052]

As described above, according to the present invention, a power line carrier communication device which is coupled to each branch power line branched from a main power line through a branch filter and performs communication using each branch power line as a communication medium. In the power line carrier communication system including: the branch filter, the two impedances inwardly seen from the respective output ends of the branch filter to which the two electric wires of the branch power lines are respectively connected are balanced, and the power line carrier the communication signal by the communication device is configured to be high impedance, the proximal conductor of the signal transmission line and ground pre
Since the impedances of the two power lines as seen from the power line are made equal, as a result, even if noise or leakage is induced by the common mode, the potential of the normal mode becomes small and it is less susceptible to the influence. On the contrary, it is possible to reduce the leakage to the nearby conductor and the ground wire due to the transmission by itself. Furthermore, by connecting either one of the main power lines to the ground line through a high-pass filter outside the branch filter, the impedance of the branch power line itself to ground is lowered, and normal mode noise and proximity of the entire signal transmission line are reduced. The influence from the conductor can be reduced.

Further, according to the present invention, a controller which is coupled to each branch power line branched from the main power line through a block filter and which transmits a remote control signal using each branch power line as a communication medium, and the controller. In a power line carrier communication system including a power line carrier communication device such as an adapter for receiving a signal for load control or a call using an audio modulated signal for intercom master unit / slave unit, the block filter,
The two impedances inwardly seen from the respective output ends of the block filter to which the two electric wires of the respective branch power lines are respectively connected are balanced, and the impedance is high for a communication signal from the power line carrier communication device. Since it is configured to have a low impedance for signals other than communication signals, further, one of the main power lines outside the block filter is connected to the ground line through a bypass filter. In addition to the above effects, passage of communication signals on the branch power line side to the main power line side can be effectively blocked.

Further, according to the present invention, the block filter includes a pair of parallel resonant circuits provided for each electric wire between a pair of input terminals and output terminals to which the main power line and the branch power line are respectively connected, and the main trunk. Since it is configured with a series resonance circuit provided between a pair of input terminals to which the power line is connected, the pass-blocking characteristic of the frequency band used for communication signals becomes steep and communication to the main power line side Signal leakage can be minimized.

Further, according to the present invention, the branch filter or the block filter and the high-pass filter in which either one of the two terminals to which the main power line of the filter is connected are connected to one terminal in advance are provided in the same casing. Since it is stored inside the body, the workability of construction is improved.

Further, according to the present invention, the wiring of each branch power line is a wiring of three lines in which the two wirings of the power line and the wiring of the ground line are close to each other, and the ground line is passed through a low-pass filter. Since the wiring structure is connected to the ground terminal, when the ground line leaks, the influence of other branch power lines on the ground line can be prevented.

Further, according to the present invention, since the low-pass filter and the branch filter or the block filter are housed in the same housing, the workability of installing the low-pass filter is improved.

According to the present invention, the impedance characteristic of the high-pass filter is formed by providing a plurality of high-pass filters having different impedance characteristics and a selection switch for selectively connecting one of the plurality of high-pass filters. Since it is variable, the occurrence of leakage can be suppressed without operating the earth leakage breaker by changing the impedance characteristics according to the sensitivity and noise level of the earth leakage breaker provided on the main power line or the like.

Further, according to the present invention, by providing the low impedance element connected between each electric wire of each branch power line and the ground wire, the impedance of the signal transmission line viewed from the ground wire is lowered. The leakage voltage level can be further reduced.

[0060]

[0061]

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power line carrier communication system showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a block filter in FIG.

FIG. 3 is a diagram showing a configuration example of a high pass filter in FIG.

4 is a system configuration diagram for comparison, which has a system configuration equivalent to that of FIG. 1 based on the conventional method of FIG.

FIG. 5 is a block diagram of a block filter showing a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a power line carrier communication system showing a third embodiment of the present invention.

FIG. 7 is a block diagram of a block film showing Example 4 of the present invention.

FIG. 8 is a configuration diagram of a power line carrier communication system showing a fifth embodiment of the present invention.

FIG. 9 is a configuration diagram of a power line carrier communication system showing a sixth embodiment of the present invention.

FIG. 10 is a configuration diagram of a power line carrier communication system showing a seventh embodiment of the present invention.

11 is a diagram showing a configuration example of a limit circuit in FIG.

FIG. 12 is a diagram showing an example of a wiring form when the lighting control system is realized by the power line carrier communication system of the present invention.

FIG. 13 is a block diagram of a block filter showing an eighth embodiment of the present invention.

FIG. 14 is a configuration diagram of a conventional power line carrier communication system.

[Explanation of symbols]

1 Commercial power supply 2 main power lines 3a, 3b block filter 4a, 4b Branch power line 5a, 5b terminals 6 ground terminal 7a, 7b Ground wire 8a, 8b high-pass filter 9 parallel resonant circuit 10a, 10b cable 11a, 11b Low pass filter 12 block filter 13 Variable characteristic high-pass filter 14 Selection switch 15 earth leakage breaker 16 Low impedance 17 Series resonance circuit 18 Limit circuit 19 Controller 20 Operation switch 21 Lighting equipment 22 block filter 23 Controller 29 distribution board

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouki Iwatsubo 5-1-1 Ofuna, Kamakura City Mitsubishi Electric Teruaki Co., Ltd. (56) Reference JP-A-4-207721 (JP, A) JP-A-60 -250739 (JP, A) JP-A-58-69441 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 3/54 H04Q 9/00 311

Claims (8)

(57) [Claims] 1. A power line carrier communication system including power line carrier communication devices, each of which is coupled to each branch power line branched from a main power line via a branching filter and performs communication using each branch power line as a communication medium. Two impedances inwardly seen from each output end of the branching filter to which two electric wires of the branching power line are respectively connected are balanced, and have high impedance for a communication signal from the power line carrier communication device. A power line comprising a configured branch filter, and a high-pass filter connected between any one of the two wires of the main power line connected to each branch filter and a ground line. Carrier communication system. 2. A controller for transmitting a remote control signal and receiving a signal from the controller, which are respectively coupled to the respective branch power lines branched from the main power line through a block filter and use the respective branch power lines as communication media. In an electric power line carrier communication system including an electric power line carrier communication device such as an adapter that performs load control by using a load control device or an intercom that performs a call using a voice modulation signal, two electric wires of each branch power line are respectively connected. The two impedances looking inward from the respective output ends of the block filter are balanced, and the impedance is high for communication signals by the power line carrier communication device and low for signals other than the communication signals. And a block filter configured as described above, Power line communications system comprising the one of the wires of the two wires of the connected main electric power line and connected to the high-pass filter between the ground line. 3. The block filter is connected to a main power line, and a pair of parallel resonant circuits provided for each electric wire between a pair of input ends and output ends to which the main power line and the branch power line are respectively connected. The power line carrier communication system according to claim 2, wherein the power line carrier communication system comprises a series resonance circuit provided between a pair of input terminals. 4. The branch filter or block filter and a high-pass filter in which one of the two terminals connected to the main power line of the filter is connected to one terminal in advance are housed in the same housing. The power line carrier communication system according to any one of claims 1 to 3, wherein the power line carrier communication system has a different structure. 5. The wiring of each branch power line is a wiring of three lines in which two wirings of the power line and a ground line are brought close to each other, and the ground line is connected to a ground terminal via a low pass filter. The wiring structure is a wiring structure.
The power line carrier communication system according to claim 4. 6. The power line carrier communication system according to claim 5, wherein the low-pass filter and the branch filter or the block filter are housed in the same housing. 7. A configuration is provided in which a plurality of high-pass filters having different impedance characteristics and a selection switch for selectively connecting one of the plurality of high-pass filters are provided in order to make the impedance characteristic of the high-pass filter variable. The power line carrier communication system according to any one of claims 1 to 3, wherein the power line carrier communication system is provided. 8. A low impedance, which is connected between each electric wire of each branch power line and a ground wire, and which makes impedance between each electric wire of each branch power line and a ground wire lower than an impedance due to a stray capacitance. The power line carrier communication system according to claim 5, wherein an element is provided.