JP2003188778A - Filtering device for power line communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a fault from occurring by lowering the impedance of an indoor power line caused by equipment connected to the indoor power line in a power line communication system for performing communications by using frequency bands within a frequency area of ≥1 MHz. <P>SOLUTION: A filtering device 30 is provided between the indoor power line and the electric equipment connected to the indoor power line. The filtering device 30 is provided with a casing 31, a plug 32 provided to be protruded from one surface 31a of the casing 31, an equipment connecting part 33 provided on a surface 31b opposite to the surface 31a and a filtering circuit 40 provided between the plug 32 and the equipment connecting part 33 inside the casing 31. The filtering circuit 40 has an impedance of ≤1 Ω within the frequency range of 0 to 120 Hz and to become ≥30 Ω within the frequency band of a width of ≥3 MHz within the frequency range of 1 to 50 MHz in the state where a current for power supply is not flowing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device for a power line communication system used in a power line communication system that enables communication between a plurality of communication devices using an indoor power line.

[0002]

2. Description of the Related Art In recent years, there has been an increasing need for information communication at home for the purpose of sharing peripheral devices of computers, sharing information such as documents, still images, moving images, games, and the Internet. . Therefore, there is a demand for communication networks not only in offices but also in general households.

Recently, power line communication has been regarded as a promising communication technology used when constructing a communication network in the home, and its development is being advanced. This power line communication uses a power line for transporting electric power as a signal transmission path. With this technique, for example,
By connecting a plurality of devices that perform communication to an outlet installed in each room of a house, it is possible to perform communication between the plurality of devices. The power line communication has advantages that it does not cost wiring work because it uses an existing power line, and does not spoil the appearance in the home. Until now, narrow band power line communication technology has been developed, which mainly uses the frequency band of 10 kHz to 450 kHz as the frequency band of the carrier wave.

[0004]

By the way, an electric device not related to power line communication is also connected to the indoor power line.
Therefore, in power line communication, due to noise generated by the electric device connected to the indoor power line and a decrease in the impedance of the indoor power line caused by the electric device connected to the indoor power line, the communication distance is shortened or a communication error occurs. There was a problem that it occurred.

As a measure against the decrease in the impedance of the indoor power line in the above-mentioned system for performing narrow band power line communication, for example, JP-A-8-98277 and JP-A-1-98277.
Japanese Unexamined Patent Publication No. 0-65583 discloses a technique of providing a filter circuit having a high impedance with respect to the frequency of a carrier wave between an indoor power line and a device that causes a decrease in impedance.

On the other hand, in response to the broadbandization of communication which has been activated in recent years, also in power line communication, broadband power line communication using a wide frequency band in a frequency region of 1 MHz or more has been proposed from the viewpoint of improving the communication speed. ing.

In the frequency band used in the broadband power line communication, the level of noise generated from the equipment connected to the indoor power line is smaller than that in the frequency band used in the narrow band power line communication, and the indoor power line is also used. The impedance of the device connected to becomes large. Therefore, broadband power line communication has been attracting attention as a high-speed and robust communication means, that is, a communication means having high tolerance to a failure factor.

However, even in broadband power line communication,
It has been confirmed that the electrical device connected to the indoor power line may lower the impedance of the indoor power line and may cause a communication failure. However, for example, Japanese Patent Laid-Open No. 8-
Conventional filter circuits such as those disclosed in Japanese Unexamined Patent Application Publication No. 98277 and Japanese Unexamined Patent Application Publication No. 10-65583 have 10 kHz to 45
It is designed to have a high impedance in a narrow band of 0 kHz. Therefore, the conventional filter circuit cannot obtain a sufficient impedance in the frequency band used in the broadband power line communication, and cannot prevent the decrease in the impedance of the indoor power line due to the electric device connected to the indoor power line. .

Further, in the power line communication system, a current for supplying power to the device flows through the filter circuit arranged between the indoor power line and the device. This current is
The maximum is from several A to a dozen A. A filter circuit in which such a large current flows is required to obtain sufficient impedance in a frequency band used for power line communication in a state where a current for power supply flows.

The present invention has been made in view of the above problems, and an object thereof is a power line communication system in which an indoor power line is used as a signal transmission path and communication is performed using a frequency band in a frequency region of 1 MHz or more. An object of the present invention is to provide a filter device for a power line communication system, which is capable of preventing a failure caused by a decrease in impedance of the indoor power line due to a device connected to the indoor power line.

[0011]

A filter device for a power line communication system of the present invention is a power line communication system which enables communication between a plurality of communication devices by using an indoor power line for transporting electric power. , Which is provided between the indoor power line and a device connected to the indoor power line, and is 0 to 0 in a state in which a current for power supply does not flow.
1Ω or less in the frequency range of 120 Hz, 1M
It is provided with a filter circuit having an impedance of 30Ω or more in a frequency band having a width of 3 MHz or more within a frequency range of Hz to 50 MHz.

In the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 1 MHz to 50 MHz.
Since it is 30Ω or more in a frequency band having a width of 3 MHz or more in the frequency range of MHz, a frequency used for power line communication in the frequency range of 1 MHz or more and capable of preventing the occurrence of a failure due to a decrease in the impedance of the indoor power line. It is possible to secure a band of 3 MHz or more. Further, in the filter device for a power line communication system of the present invention, the impedance of the filter circuit is 0 to 1
Since it is 1Ω or less in the frequency range of 20 Hz, it does not hinder the passage of the current for power supply in the frequency range of 0 to 120 Hz.

In the filter device for a power line communication system of the present invention, in a state in which a current for power supply is not flowing,
The impedance of the filter circuit is 1MHz to 50MH
It may be 300Ω or more in a frequency band having a width of 3 MHz or more in the frequency range of z.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 1 MHz to 5 when the current for power supply is not flowing.
It may be 1 kΩ or more in a frequency band having a width of 3 MHz or more in the frequency range of 0 MHz.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 1 MHz to 5 when the current for power supply is not flowing.
It may be 300Ω or more in a frequency band having a width of 10 MHz or more in the frequency range of 0 MHz.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 1 MHz to 5 when a current for supplying power is not flowing.
It may be 1 kΩ or more in a frequency band having a width of 10 MHz or more in the frequency range of 0 MHz.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 4 MHz to 2 when a current for power supply is not flowing.
It may be 30Ω or more in the frequency range of 1 MHz.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 4 MHz to 2 when the current for power supply is not flowing.
It may be 300Ω or more in the frequency range of 1 MHz.

Further, in the filter device for the power line communication system of the present invention, the impedance of the filter circuit is 4 MHz to 2 in the state where the current for power supply is not flowing.
It may be 1 kΩ or more in the frequency range of 1 MHz.

Further, in the filter device for a power line communication system of the present invention, the current passing through the filter circuit is 7A.
In the following cases, the impedance of the filter circuit is 1M
It may be 30Ω or more in a frequency band having a width of 3MHz or more in the frequency range of Hz to 50MHz.

In the power line communication system filter device of the present invention, the current passing through the filter circuit is 10
When A or less, the impedance of the filter circuit is 1
It may be 30Ω or more in a frequency band having a width of 3MHz or more in the frequency range of MHz to 50MHz.

In the power line communication system filter device of the present invention, the current passing through the filter circuit is 15
When A or less, the impedance of the filter circuit is 1
It may be 30Ω or more in a frequency band having a width of 3MHz or more in the frequency range of MHz to 50MHz.

In the power line communication system filter device of the present invention, the current passing through the filter circuit is 20.
When A or less, the impedance of the filter circuit is 1
It may be 30Ω or more in a frequency band having a width of 3MHz or more in the frequency range of MHz to 50MHz.

In the filter device for the power line communication system of the present invention, the resistance of the filter circuit is 50 to 60.
It may be 10 mΩ or less in the frequency range of Hz.

In the filter device for the power line communication system of the present invention, the resistance of the filter circuit is 50 to 60.
It may be 5 mΩ or less in the frequency range of Hz.

Further, in the filter device for the power line communication system of the present invention, the filter circuit may include an inductor connected in series to the indoor power line. In this case, the inductor may have a magnetic core and a winding wound around the magnetic core, and the initial relative permeability of the magnetic core may be 100 or more at a frequency of 10 MHz.

In the filter device for a power line communication system of the present invention, the indoor power line includes a live line and a neutral line, and the filter circuit includes two inductors connected in series to the live line and the neutral line, respectively. You may stay. In this case, each of the two inductors may have a magnetic core and a winding wound around the magnetic core, and the initial relative permeability of the magnetic core may be 100 or more at a frequency of 10 MHz.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, with reference to FIG. 1, an example of a power line communication system to which a filter device for a power line communication system (hereinafter, simply referred to as a filter device) according to an embodiment of the present invention is applied will be described. The power line communication system includes an indoor power line 1 and a blocking filter 50 connected to the indoor power line 1. The indoor power line 1 is connected to the outdoor power line 51 via the blocking filter 50. Figure 1
In, the reference numeral 10 represents the room.

The indoor power line 1 is, for example, three conductive lines 1.
a, 1b, 1c are included. The outdoor power line 51 includes, for example, three conductive lines 51a, 51b, 51c connected to the conductive lines 1a, 1b, 1c of the indoor power line 1.
The indoor power line 1 and the outdoor power line 51 are, for example, single-phase three-wire power lines. In this case, the conductive wires 1a, 1
c, 51a, 51c are live lines having a potential different from the ground potential, and the conductive lines 1b, 51b are neutral lines having a ground potential.

The power line communication system is further connected to the indoor power line 1, receives power from the indoor power line 1, and uses the indoor power line 1 as a signal transmission path to perform power line communication with each other. 11 and 12 are provided. Computers are examples of the power line communication devices 11 and 12. Power line communication device 11, 12
Respectively have power line communication terminals 13 and 14 that are connected to the indoor power line 1 and perform power line communication with each other. The power line communication terminals 13 and 14 are the conductive lines 1 of the indoor power line 1.
It is connected to a and 1b.

To the conductive lines 1a and 1b of the indoor power line 1, in addition to the power line communication terminals 13 and 14, electric devices 21, 22, 23 and 24 which are supplied with power from the indoor power line 1 are connected. Some of these electric devices 21 to 24 cause a decrease in impedance of the indoor power line 1 and generate noise. The power line communication system further includes a filter device 30 according to the present embodiment provided between the indoor power line 1 and each of the electric devices 21 to 24.

In the power line communication system shown in FIG. 1, the power line communication devices 11 and 12 are the power line communication terminals 1 and 12.
Power line communication is performed using the power line 1 via the terminals 3 and 14. In the present embodiment, the frequency band of the carrier wave in power line communication is a frequency band having a width of 3 MHz or more in a frequency region of 1 MHz or more.

Next, the filter device 30 according to the present embodiment will be described with reference to FIG. FIG. 2 is a perspective view showing the appearance of the filter device 30. Filter device 30
Is, for example, a rectangular parallelepiped casing 31 and one of the casings 31.
Plug 32 provided so as to protrude from one surface 31a
And a device connection portion 33 provided on the surface 31b opposite to the surface 31a, and a filter circuit 40 provided between the plug 32 and the device connection portion 33 in the housing 31.

The plug 32 is detachably and electrically connected to an unillustrated outlet (receptacle) connected to the indoor power line 1. This plug 32
Has two terminal portions 32a and 32b. The device connecting portion 33 has a structure similar to that of the above outlet. A plug of an electric device is detachably and electrically connected to the device connecting portion 33. The device connection part 33 has two terminal parts 33a and 33b. The filter circuit 40 includes a conductor portion 4 that electrically connects the terminal portion 32a of the plug 32 and the terminal portion 33a of the device connecting portion 33.
1a, a conductor portion 41b for electrically connecting the terminal portion 32b of the plug 32 and the terminal portion 33b of the device connecting portion 33, and an inductor 4 provided in the middle of each conductor portion 41a, 41b.
2a and 42b. Inductors 42a, 42
b is connected in series to the indoor power line 1. Also,
The inductors 42a and 42b have the same characteristics.

The plug 32 of the filter device 30 is electrically connected to an outlet (not shown) connected to the indoor power line 1, and the device connecting portion 33 of the filter device 30 has the plug of any one of the electric devices 21 to 24. It is electrically connected. Thereby, the electric devices 21 to 24 are electrically connected to the indoor power line 1 via the filter device 30,
Power is supplied from the indoor power line 1.

The terminal portion 32a of the plug 32 is connected to one of the live line and the neutral line, and the terminal portion 32b of the plug 32 is connected to the other of the live line and the neutral line. Therefore, the inductor 42a is connected in series to one of the live line and the neutral line,
b is connected in series to the other of the live line and the neutral line.

FIG. 3 is a circuit diagram showing an example of the configuration of the filter circuit 40. The filter circuit 40 shown in FIG. 3 includes the above-described conductor portions 41a and 41b and inductors 42a and 4a.
2b.

The inductors 42a and 42b are respectively
It has a magnetic core and a winding wound around the magnetic core. As the material of the magnetic core, for example, an amorphous magnetic material or a ferrite having a spinel structure can be used. Ferrite includes Mn-based, Ni-based, Mn-Zn-based, Ni-Zn-based,
Various composition systems such as Mg-Mn system and Cu-Zn system can be used. The initial relative permeability of the magnetic core is 10MHz
It is preferable that the frequency is 100 or more.

FIG. 3 is a circuit diagram showing another example of the configuration of the filter circuit 40. The filter circuit 40 shown in FIG.
In addition to the configuration of the filter circuit 40 shown in FIG. 3, a capacitor 43 is provided between the inductors 42a and 42b and the device connecting portion 33 and provided between the conductor portions 41a and 41b. Therefore, the filter circuit 40 shown in FIG. 4 has an LC filter configuration.

The characteristics of the filter circuit 40 will be described in detail below. In broadband power line communication, it is desirable to secure a frequency band having a width of 3 MHz or more in a frequency region of 1 MHz or more. The filter circuit 40 in the present embodiment is set to 0 when no current for power supply is flowing.
1Ω or less in the frequency range of ~ 120Hz, 1
It has an impedance of 30Ω or more in a frequency band having a width of 3 MHz or more in the frequency range of MHz to 50 MHz.

Therefore, according to the filter device 30 of the present embodiment, the impedance of the filter circuit 40 is 1 or less.
Since it is 30Ω or more in the frequency band having a width of 3 MHz or more within the frequency range of 50 MHz to 50 MHz, the occurrence of a failure due to a decrease in the impedance of the indoor power line 1 which is used for power line communication in the frequency region of 1 MHz or more. The frequency band that can be prevented is 3 MHz
The above can be secured. Further, according to the filter device 30 of the present embodiment, the impedance of the filter circuit 40 is 1 in the frequency range of 0 to 120 Hz.
Since it is Ω or less, it does not hinder the passage of a current for power supply in the frequency range of 0 to 120 Hz.

In the filter device 30, the impedance of the filter circuit 40 is preferably 300 Ω or more in the frequency band of 3 MHz or more in the frequency range of 1 MHz to 50 MHz when the current for power supply is not flowing. .

Further, in the filter device 30, the impedance of the filter circuit 40 is 1 k in the frequency band of 3 MHz or more in the frequency range of 1 MHz to 50 MHz when the current for power supply is not flowing.
It is more preferably Ω or more.

Further, in the filter device 30, the impedance of the filter circuit 40 is 3 in the frequency band of 10 MHz or more in the frequency range of 1 MHz to 50 MHz when the current for power supply is not flowing.
It is preferably 00Ω or more.

Further, in the filter device 30, the impedance of the filter circuit 40 is 1 in the frequency band of 10 MHz or more in the frequency range of 1 MHz to 50 MHz in the state where the current for power supply does not flow.
It is more preferably kΩ or more.

By the way, in the broadband power line communication, it is considered to use a frequency band of 4 MHz to 21 MHz, for example. Therefore, in the filter device 30, the filter circuit 40 is operated in the state where the current for power supply does not flow.
May have an impedance of 30Ω or more in the frequency range of 4 MHz to 21 MHz. In this case, the frequency band of 4 MHz to 21 MHz can be used as a frequency band used for power line communication and capable of preventing a failure due to a decrease in impedance of the indoor power line 1.

In the filter device 30, the impedance of the filter circuit 40 is preferably 300Ω or more in the frequency range of 4 MHz to 21 MHz in the state where the current for power supply does not flow, and is preferably 1 k.
It is more preferably Ω or more.

In the filter device 30, when the current passing through the filter circuit 40 is 7 A or less, the impedance of the filter circuit 40 is 1 MHz to 50 MHz.
Is 30Ω or more in the frequency band having a width of 3 MHz or more in the frequency range of. Many household electric appliances that use a voltage of 100 V have a power consumption of 700 W or less, that is, an operating current of 7 A or less. Filter device 30
Can prevent the occurrence of a failure due to a decrease in the impedance of the indoor power line 1 when at least an electric device having a used current of 7 A or less is connected to the indoor power line 1 via the filter device 30.

The rated current of the outlet connected to the indoor power line 1 varies from country to country, and the rated current is 1
0A, 12A, 13A, 15A, 16A, etc.

In the filter device 30 according to this embodiment, the impedance of the filter circuit 40 is 1 MH when the current passing through the filter circuit 40 is 10 A or less.
It may be 30Ω or more in a frequency band having a width of 3 MHz or more in the frequency range of z to 50 MHz. In this case, the filter device 30 is provided between the outlet having a rated current of 10 A or less and the electric device having a working current of 10 A or less.
By providing the, it is possible to prevent the occurrence of a failure due to a decrease in the impedance of the indoor power line 1.

In the filter device 30, when the current passing through the filter circuit 40 is 15 A or less, the impedance of the filter circuit 40 is 1 MHz to 50 MH.
It may be 30Ω or more in the frequency band having a width of 3 MHz or more in the frequency range of z. In this case,
An outlet with a rated current of 15A or less and a working current of 15A
By providing the filter device 30 between the following electric devices, it is possible to prevent a failure due to a decrease in impedance of the indoor power line 1.

In the filter device 30, when the current passing through the filter circuit 40 is 20 A or less, the impedance of the filter circuit 40 is 1 MHz to 50 MH.
It may be 30Ω or more in the frequency band having a width of 3 MHz or more in the frequency range of z. In this case,
An outlet with a rated current of 20A or less and a working current of 20A
By providing the filter device 30 between the following electric devices, it is possible to prevent a failure due to a decrease in impedance of the indoor power line 1.

Further, the frequencies of electric power transported by the indoor power line 1 are mostly 50 Hz and 60 Hz worldwide. Therefore, it is preferable that the filter device 30 does not prevent passage of a current for power supply in the frequency range of 50 to 60 Hz. Therefore, in the filter device 30, the resistance of the filter circuit 40 is preferably 10 mΩ or less, and more preferably 5 mΩ or less in the frequency range of 50 to 60 Hz. Further, the power consumption of the filter circuit 40 is preferably 1 W or less.

Hereinafter, first to third examples of the filter device 30 according to the present embodiment will be described with reference to FIGS. 5 and 6. In any of the embodiments, the filter circuit 40 has the structure shown in FIG.
FIG. 5 shows the frequency characteristics of the impedance of the filter circuit 40 in the first to third embodiments. The characteristics shown in FIG. 5 are measured in a state in which a current for power supply does not flow through the filter circuit 40.

As shown in FIG. 5, in the frequency characteristics of the impedance of each filter circuit 40 in the first to third embodiments, in the state where no current for power supply is flowing in the filter circuit 40, 1 MHz to 10
The impedance is 30Ω or more over the entire frequency range of 0 MHz. Further, although not shown in FIG. 5, the impedance of each filter circuit 40 in the first to third embodiments is the following when no current for power supply is flowing in the filter circuit 40:
It is 1 Ω or less in the frequency range of 0 to 120 Hz.

The impedance of the filter circuit 40 in the first embodiment has a maximum value of about 4 kΩ when the frequency is about 30 MHz. The impedance of the filter circuit 40 in the first embodiment has a frequency of 1 MHz to 100 M.
It becomes 300Ω or more in the range of Hz. Further, the impedance of the filter circuit 40 in the first embodiment becomes 1 kΩ or more in the frequency range of 3.2 MHz to 100 MHz. The impedance of the filter circuit 40 in the first embodiment has a frequency of 14.5 MHz to 49.5 M.
It becomes 3 kΩ or more in the range of Hz.

The impedance of the filter circuit 40 in the second embodiment has a maximum value of about 400Ω when the frequency is about 60 MHz. The impedance of the filter circuit 40 in the second embodiment has a frequency of 24 MHz to 10 MHz.
It becomes 300Ω or more in the range of 0 MHz.

The impedance of the filter circuit 40 in the third embodiment has a maximum value of about 7 kΩ when the frequency is about 5 MHz. Filter circuit 4 in the third embodiment
The impedance of 0 has a frequency of 1 MHz to 56 MHz.
Is 300Ω or more in the range. The impedance of the filter circuit 40 in the third embodiment is 1 kΩ or more in the frequency range of 1.2 MHz to 19.5 MHz. The impedance of the filter circuit 40 in the third embodiment has a frequency of 2.8 MHz to 8.3 MHz.
Is 3 kΩ or more in the range of.

Although not shown, the impedance of each filter circuit 40 in the first to third embodiments is
In both cases, when the current passing through the filter circuit 40 is 20 A or less, it is 30Ω or more in the frequency band of 3 MHz or more in the frequency range of 1 MHz to 50 MHz.

The resistance of each filter circuit 40 in the first to third embodiments is 50 to 60 Hz.
Within the frequency range of, it is 5 mΩ or less. In each of the filter circuits 40 of the first to third embodiments, the power consumption of the filter circuit 40 is 1 W or less.

FIG. 6 shows a case where the filter device 30 according to any one of the first to third embodiments is provided between the indoor power line 1 and the electric equipment and the filter device between the indoor power line 1 and the electric equipment. The results of measuring the transmission characteristics of the indoor power line 1 are shown for the case where 30 is not provided. In FIG. 6, the horizontal axis represents frequency and the vertical axis represents power attenuation (unit: dBm).

As can be seen from FIG. 6, the filter device 30
When not provided, the power attenuation amount exceeds -15 dB in the frequency region near 10 MHz, and the power attenuation amount exceeds -10 dB in the frequency region near 50 MHz. Therefore, the indoor power line 1 in this case is 1
It is not in a state suitable for wideband power line communication using frequencies above MHz.

On the other hand, the filter device 3 according to the first or second embodiment is provided between the indoor power line 1 and the electric equipment.
When 0 is provided, the power attenuation amount does not exceed −5 dB in the frequency range of 1 MHz to 100 MHz. Therefore, the indoor power line 1 in this case is in a state suitable for wideband power line communication using a frequency of 1 MHz or higher. Particularly, when the filter device 30 according to the first embodiment is provided between the indoor power line 1 and the electric device, 2
The amount of power attenuation does not exceed -1 dB in the frequency range of MHz to 100 MHz, and the transmission characteristics of the indoor power line 1 are good over a wide frequency range.

When the filter device 30 of the third embodiment is provided between the indoor power line 1 and the electric equipment, it is 1M.
In the frequency range from Hz to 60 MHz, the power attenuation is −
It does not exceed 1 dB. Therefore, the indoor power line 1 in this case is in a state suitable for wideband power line communication using a frequency of 1 MHz or higher.

As described above, according to the filter device 30 of the present embodiment, the indoor power line 1 is used as a signal transmission path, and 3 in the frequency region of 1 MHz or more is used.
In a power line communication system that performs communication using a frequency band having a width of at least MHz, the impedance of the indoor power line 1 caused by the electric device is affected without affecting the power supply to the electric device connected to the indoor power line 1. It is possible to prevent the deterioration.

Further, the filter device 3 according to the present embodiment
At 0, the impedance of the filter circuit 40 is sufficiently large in the frequency band used for power line communication even when the current for power supply is flowing through the filter circuit 40. Therefore, according to the present embodiment, it is possible to more reliably prevent the impedance of the indoor power line 1 from being lowered due to the electric device without affecting the supply of electric power to the electric device connected to the indoor power line 1. can do.

Further, the filter device 3 according to the present embodiment
At 0, the filter circuit 40 includes two inductors 42a, 42b, which are each connected in series with the live line and the neutral line of the indoor power line 1. Therefore, in the present embodiment, the case where the terminal portions 32a and 32b of the plug 32 are connected to the live line and the neutral line respectively, and the case where the plug 3
There is no difference in the circuit configuration between the case where the two terminal portions 32a and 32b are connected to the neutral line and the live line, respectively. Therefore, according to the present embodiment, regardless of the connection relationship between the plug 32 of the filter device 30 and the indoor power line 1, it is possible to reliably prevent the impedance of the indoor power line 1 from decreasing due to the electric device. You can

Further, the filter device 3 according to the present embodiment
According to 0, the filter circuit 40 can reduce the normal mode noise generated from the electric device. As a result, it is possible to prevent normal mode noise from occurring in the indoor power line 1.

From the above, according to the filter device 30 of the present embodiment, it is possible to prevent the occurrence of communication failure due to the electric equipment connected to the indoor power line 1. As a result, it is possible to improve communication performance such as improvement of communication speed in power line communication.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, the filter device 30 in the embodiment is configured to be detachably connected to both an outlet (not shown) connected to the indoor power line 1 and an electric device. It may be built in the electric device.

[0071]

As described above, according to the first to the eighteenth aspects.
The filter device for a power line communication system according to any one of 0 to 12 in a state in which a current for power supply does not flow.
1Ω or less in the frequency range of 0Hz, 1MHz
The filter circuit has an impedance of 30Ω or more in a frequency band having a width of 3 MHz or more in a frequency range of ˜50 MHz. Therefore, according to the present invention, the indoor power line is used as a signal transmission path, and
In a power line communication system that performs communication using a frequency band in the frequency range of Hz or higher, it is possible to prevent the occurrence of a failure due to a decrease in the impedance of the indoor power line due to a device connected to the indoor power line.

According to the filter device for a power line communication system according to any one of claims 6 to 8, 4 MH
The frequency band of z to 21 MHz can be used as a frequency band used for power line communication and capable of preventing a failure due to a decrease in impedance of an indoor power line.

According to the filter device for a power line communication system according to any one of claims 9 to 12, the electric power is not caused by the electric device without affecting the electric power supply to the electric device connected to the indoor power line. As a result, it is possible to more reliably prevent the impedance of the indoor power line from decreasing.

Further, in the filter device for a power line communication system according to claim 17 or 18, the indoor power line includes a live line and a neutral line, and the filter circuit includes two live lines and a neutral line respectively connected in series. Including inductor. Therefore, according to the present invention, regardless of the connection relationship between the filter device and the indoor power line, it is possible to reliably prevent the impedance of the indoor power line from decreasing due to the electric device.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a power line communication system to which a filter device according to an embodiment of the present invention is applied.

FIG. 2 is a perspective view showing an appearance of a filter device according to an embodiment of the present invention.

FIG. 3 is a circuit diagram showing an example of a configuration of a filter circuit according to an embodiment of the present invention.

FIG. 4 is a circuit diagram showing another example of the configuration of the filter circuit according to the embodiment of the present invention.

FIG. 5 is a characteristic diagram showing frequency characteristics of impedance of the filter circuit in the first to third examples of the embodiment of the present invention.

FIG. 6 shows the case where the filter device according to any one of the first to third embodiments is provided between the indoor power line and the device and the case where the filter device is not provided between the indoor power line and the device. It is a characteristic view which shows the result of having measured the transmission characteristic.

[Explanation of symbols]

1 ... Indoor power line, 11, 12 ... Power line communication device, 13,
14 ... Power line communication terminal, 21-24 ... Electric device, 30 ...
Filter device, 31 ... Casing, 32 ... Plug, 33 ... Equipment connection part, 40 ... Filter circuit, 41a, 41b ... Conductor part, 42a, 42b ... Inductor.

Claims (18)

[Claims] 1. In a power line communication system that enables communication between a plurality of communication devices using an indoor power line for transporting electric power, between an indoor power line and a device connected to the indoor power line. Is a filter device for a power line communication system, which is provided in
1 Ω or less in the frequency range of z, 1 MHz to 5
A filter device for a power line communication system, comprising a filter circuit having an impedance of 30Ω or more in a frequency band having a width of 3 MHz or more in a frequency range of 0 MHz. 2. The impedance of the filter circuit is in the range of 1 MHz when a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, which has a resistance of 300Ω or more in a frequency band having a width of 3 MHz or more within a frequency range of 50 MHz. 3. The impedance of the filter circuit is from 1 MHz in the state where a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a power band of 1 kΩ or more in a frequency band having a width of 3 MHz or more within a frequency range of 50 MHz. 4. The impedance of the filter circuit is in the range of 1 MHz when a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 300Ω or more in a frequency band having a width of 10 MHz or more within a frequency range of 50 MHz. 5. The impedance of the filter circuit is from 1 MHz in a state in which a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a power band of 1 kΩ or more in a frequency band having a width of 10 MHz or more within a frequency range of 50 MHz. 6. The impedance of the filter circuit is 4 MHz or more in a state where a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 30Ω or more in a frequency range of 21 MHz. 7. The impedance of the filter circuit is in the range of 4 MHz in a state in which a current for power supply is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 300Ω or more in a frequency range of 21 MHz. 8. The impedance of the filter circuit is 4 MHz or more when a current for supplying power is not flowing.
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 1 kΩ or more in a frequency range of 21 MHz. 9. The current passing through the filter circuit is 7A.
The impedance of the filter circuit is
3MHz in the frequency range of 1MHz to 50MHz
The filter device for a power line communication system according to any one of claims 1 to 8, wherein the frequency band of the above width is 30Ω or more. 10. The current passing through the filter circuit is 1
When it is 0 A or less, the impedance of the filter circuit is 3 M in the frequency range of 1 MHz to 50 MHz.
9. The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 30Ω or more in a frequency band having a width of Hz or more. 11. The current passing through the filter circuit is 1
When it is 5 A or less, the impedance of the filter circuit is 3 M in the frequency range of 1 MHz to 50 MHz.
9. The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 30Ω or more in a frequency band having a width of Hz or more. 12. The current passing through the filter circuit is 2
When it is 0 A or less, the impedance of the filter circuit is 3 M in the frequency range of 1 MHz to 50 MHz.
9. The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 30Ω or more in a frequency band having a width of Hz or more. 13. The filter circuit has a resistance of 50 to 6
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 10 mΩ or less in a frequency range of 0 Hz. 14. The resistance of the filter circuit is 50 to 6
The filter device for a power line communication system according to claim 1, wherein the filter device has a resistance of 5 mΩ or less within a frequency range of 0 Hz. 15. The filter device for a power line communication system according to claim 1, wherein the filter circuit includes an inductor connected in series to the indoor power line. 16. The inductor has a magnetic core and a winding wound around the magnetic core, and the initial relative permeability of the magnetic core is:
The filter device for a power line communication system according to claim 15, wherein the frequency is 100 or more at a frequency of 10 MHz. 17. The indoor power line includes a live line and a neutral line, and the filter circuit includes two inductors connected in series to the live line and the neutral line, respectively. Through 14
A filter device for a power line communication system according to any one of 1. 18. Each of the two inductors has a magnetic core and a winding wound around the magnetic core, and the initial relative permeability of the magnetic core is 100 or more at a frequency of 10 MHz. The filter device for a power line communication system according to claim 17.