JP4706044B2 - Power line communication system - Google Patents

Description

  The present invention relates to a power line communication system, and more particularly to an injection unit that magnetically couples a high frequency signal to a plurality of power lines to superimpose a signal to be transmitted and extract a signal to be received.

  When constructing a communication system using a power line drawn into the home, means for superposing a high-frequency signal (frequency band of 2 MHz to 30 MHz) on the power line is required. As a basic configuration in that case, there is a method of injection using a ferrite core 51 as shown in FIG. 10 (see Patent Document 1). In this method, the power line 50 and the signal line 52 are sandwiched between the power lines 50 drawn into the home using the ferrite core 51, and the high frequency signal transmitted from the modem 53 via the signal line 52 is magnetically coupled to the power line. 50 is superimposed. When the modem 53 receives a high-frequency signal, the high-frequency signal superimposed on the power line 50 appears on the surface of the power line 50 due to the skin effect. Therefore, if the signal line 52 is sandwiched between the surfaces of the power line 50, Only the high frequency signal can be taken out by the magnetic coupling force.

  In Japan, the power distribution system (TT system) is composed of three power lines, two power lines and a neutral line installed on the ground. Therefore, since the high frequency signal superimposed on the power line is always superimposed on one of the neutral line and the other power line, the high frequency signal can be always received by connecting the modem to a 100 V commercial power source.

FIG. 11 is a conceptual diagram of a TT system adopted in a Japanese power distribution system. The middle point of the secondary side of the pole transformer 40 is grounded by the ground line 41 to the ground. Therefore, the voltage at both ends of the transformer 40 (between the power lines 42 and 43) is 200V, but is 100V between the transformer 40 and the neutral line 44. And the electric power is integrated by the watt-hour meter 49 in a consumer through the breaker of the electric power company which is not shown in figure, and the 3-wire power line enters into the distribution board 45, and each household appliance via each breaker 45a, 45b, 45c 46, 47, 48. Therefore, for example, if the home appliance 46 is a PC, a modem in the PC can receive and communicate with a high-frequency signal superimposed on the power line 42 and the neutral line 44.
JP 2004-032585 A

However, in apartment houses such as apartments, the value of the current flowing through the power line varies greatly depending on the time of day. For example, since it is a time zone in which home appliances are operating during the daytime, the current value is large, and since the lighting is turned on all at once from evening to night, the current value further increases and reaches a peak. And the electric current value becomes the minimum in the time slot | zone when each household goes out and goes to bed. Therefore, since the fluctuation range of the current is large unlike a detached house, the core of the injection part is provided with a notch (gap) so as not to be magnetically saturated by the peak current. However, if the gap width is widened, the core is difficult to saturate, but the amount of signal injection (data amount per time) decreases, and if it is narrowed, the amount of signal injection increases, but the core tends to saturate. There is a problem.
In addition, the conventional technique disclosed in Patent Document 1 has a problem that since the core is not provided with a gap, the core is magnetically saturated depending on the current value, so that signals cannot be sufficiently injected.

  In view of such a problem, the present invention enables a constant signal injection without being influenced by the current value by adopting a configuration in which the gap shape of the core used in the injection section can be adapted to the magnitude of the current value flowing through the power line. An object of the present invention is to provide a simple power line communication system.

In order to solve such a problem, the present invention provides a power line communication system that transmits and receives signals by superimposing a high-frequency signal on a power line, superimposing a signal to be transmitted to the power line and receiving the signal. An injection unit for extracting a signal to be processed, wherein the injection unit includes at least two or more cores, and each core is a cylindrical body that engages with an outer periphery of the power line, and a part thereof The notch portions extending in the axial direction are provided, the gap intervals of the notch portions are different from each other, and the circumferential positions of the notch portions of the cores are relatively shifted by 90 degrees or more. To do.
The basic configuration of the injection unit used in the power line communication system is a core and a signal line. The core is provided with a notch so as not to cause magnetic saturation due to the current flowing through the power line. Further, the saturation method differs depending on the gap interval size of the notch, and as the gap interval becomes larger, the saturation becomes difficult, but the data injection amount decreases. Therefore, in the present invention, the gap intervals of the respective cutout portions of the cores are made different from each other, and a magnetic field leaks to the outside from the cutout portions of the core. Therefore, in order to prevent the leaked magnetic field from affecting the adjacent core, it is necessary to separate the positions of the notches. Therefore, in the present invention, adjacent notch portions are arranged at positions different by 90 degrees or more.

A second aspect of the present invention includes a signal line that is magnetically coupled to the power line via the cores, a timing unit, a signal line selection unit that selects the signal line, and a control unit, and the control unit includes the control unit When a signal is superimposed on a power line, a signal line is selected by the signal line selector based on the time measured by the time measuring means, and the signal is supplied to the selected signal line.
The value of the current flowing through the power line varies depending on the time zone. For example, in a housing complex such as a condominium, the current value varies greatly between morning, noon, night, and midnight, and the tendency does not change significantly throughout the year. Therefore, in the present invention, such a tendency is grasped in advance, a current value in each time zone is assumed, and a signal line corresponding to the current value is selected.

According to a third aspect of the present invention, when the control unit detects that the current value flowing through the power line becomes large, the control unit selects a core signal line with a large gap interval between the notches, and the current When it is detected that the time is a time when the value decreases, a core signal line with a small gap interval between the notches is selected, and the signal is supplied to the selected signal line.
When the current value of the power line is large, the core is likely to be magnetically saturated, so it is necessary to increase the gap interval between the notches. On the other hand, when the current value of the power line is small, the core is less likely to be magnetically saturated. Therefore, it is necessary to reduce the gap interval between the notches and increase the data injection amount. Therefore, in the present invention, the relationship between the time zone and the current value is examined in advance, and in the time zone where the current value is large, a core signal line having a large gap interval between the notches is selected and the time zone where the current value is small. In this case, a core signal line with a small gap interval between the notches is selected.

According to a fourth aspect of the present invention, there is provided a signal line that magnetically couples the signal through the cores, a current value measuring unit that measures a current value flowing through the power line, a signal line selection unit that selects the signal line, and a control unit. And when the signal is superimposed on the power line, the control unit measures the current value flowing through the power line by the current value measuring unit, and the signal line selection unit determines a signal according to the measured current value. A line is selected, and the signal is supplied to the selected signal line.
The present invention includes means for individually penetrating a signal line in each core and measuring a current value of a power line, and a selection unit for selecting which signal line to supply a signal to. Then, while measuring the current value, the signal line is selected so as to select the core having the gap interval of the notch that is optimal for the current value, and the signal is supplied to the signal line.

Claim 5, wherein, when the current value measured by the current value measuring means is judged to have exceeded a predetermined value, selects the signal line of the notch core gap spacing is large, the When it is determined that the current value has fallen below a predetermined value, a core signal line having a small gap interval between the notches is selected, and the signal is supplied to the selected signal line.
When the current value measured by the current value measuring means exceeds a predetermined value, the core signal line having a large gap interval between the notches is selected so that the core is not magnetically saturated. Conversely, when the measured current value is equal to or less than the predetermined value, the core is difficult to be magnetically saturated. Therefore, in order to increase the signal injection amount, the core signal line with a small gap between the notches is selected.

  According to the present invention, each core has a loop shape having a notch in a part thereof, and the gap interval between the notches is different, so that the magnetic saturation does not occur according to the magnitude of the current value flowing through the power line. A core can be used.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
Fig.1 (a) is an external view of the schematic block diagram which shows a part of injection part based on the 1st Embodiment of this invention, FIG.1 (b) is a schematic diagram. The injection unit 100 includes a core 3 having a notch portion 5 having a small gap interval, a signal line 8 for magnetically coupling a signal through the core 3, a core 1 having a notch portion 6 having a large gap interval, 1, and a signal line 7 that magnetically couples the signal via 1, and is attached to be wound around the power line 4. The signal lines 7 and 8 are provided so as to be in close contact with the power line 4, and are arranged so that the notch 5 and the notch 6 are in the same position. In FIG. 1A, two types of cores are illustrated, but more types may be provided. Further, by separating the core 1 and the core 3 so as to provide the interval 2, magnetic mutual interference can be reduced.

  FIG. 1B is a diagram schematically showing the configuration of FIG. 1A, and the same components are described with the same reference numerals as those in FIG. As described above, when the current I flows through the power line 4, depending on the current value, the core causes magnetic saturation, and the amount of signals injected from the outside decreases. In general, regarding the relationship between the current due to the gap interval and the signal injection amount, when the gap interval is small, magnetic saturation tends to occur, but the signal injection amount increases. When the gap interval is large, magnetic saturation is difficult, but the signal injection amount is small. From this relationship, in this embodiment, at least two or more cores are provided, and the gap intervals of the cutout portions of the respective cores are made different. That is, when the current I is large, a signal is injected from the signal line 7 provided in the core 1 having a large gap interval 6. Conversely, when the current I is small, a signal is injected from the signal line 8 provided in the core 3 having a small gap interval 5. When the current value of the power line 4 cannot be determined from the outside, the same signal is always supplied to the signal lines 7 and 8 (one signal line may pass through both cores). A signal is automatically injected from a core that is not magnetically saturated depending on the current value.

FIG. 2A is an external view of a schematic configuration diagram showing a part of an injection unit according to the second embodiment of the present invention, and FIG. 2B is a schematic diagram. 2 is different from FIG. 1 in that the positional relationship between the notches 5 and 6 is arranged at an angle where the relative position of each other is 90 degrees or more. That is, the magnetic field leaks from the notches 5 and 6 of the core to the outside. Therefore, in order to prevent the leaked magnetic field from affecting the adjacent cores, it is desirable to keep the positions of the notches as far as possible. For example, when there are two cores and the interval 2 is a constant value, the distance between the notches 5 and 6 on the circumference of the power line 4 is the longest when the relative positions are arranged at angles different by 180 degrees. It is. Thereby, the interference of the adjacent cores 1 and 3 can be minimized.
The above embodiment is an example, and if each of the opposing edges 1a, 1b or 3a, 3b constituting the notch is linear and parallel, it is parallel to the axial direction of the power line 4. It doesn't have to be.

  FIG. 3A is an external view of a schematic configuration diagram showing a part of an injection unit according to the third embodiment of the present invention, and FIG. 3B is a schematic diagram. The injection unit 300 includes a core 12 having a stepped notch having a small gap interval 13 and a large gap interval 14, and a signal line 17 for magnetically coupling signals via the core 12, and the power line 11. It is attached so as to be wound around. The signal line 17 is provided in close contact with the power line 11.

FIG. 3B is a diagram schematically showing the configuration of FIG. 3A, and the same components will be described with the same reference numerals as those in FIG. 3A. In FIG. 1 and FIG. 2, the injection part is configured by two cores having different gap intervals, and signal lines are also required individually. In the present embodiment, one core is provided with a stepped notch having different gap intervals and one signal line. That is, when the shape of the cutout portion of the core is stepped and the core is provided with one signal line 17 and the current flowing through the power line 11 is large, the core of the portion 14 having a large stepped gap interval works. When a signal is injected and the current flowing through the power line 11 is small, the core of the portion 13 having a small step gap is operated to inject a larger amount of signal. Thereby, the optimal signal amount can be injected by one signal line 17 regardless of the magnitude of the current.
The above embodiment is an example, and FIG. 3A illustrates a two-step staircase shape, but any number of steps may be used.

  FIG. 4A is an external view of a schematic configuration diagram showing a part of an injection unit according to the fourth embodiment of the present invention, and FIG. 4B is a schematic diagram. The injection unit 400 includes a core 15 having a wedge-shaped notch with a gap interval 16 and a signal line 18 that magnetically couples a signal through the core 15, and is attached to be wound around the power line 11. Yes. The signal line 18 is provided in close contact with the power line 11.

FIG. 4B is a diagram schematically showing the configuration of FIG. 4A, and the same components will be described with the same reference numerals as those in FIG. 4A. In FIG. 1 and FIG. 2, the injection part is configured by two cores having different gap intervals, and signal lines are also required individually. In the present embodiment, a wedge-shaped cutout having gradually different gap intervals is provided in one core, and the number of signal lines is also one. That is, when the shape of the notch of the core 15 is wedge-shaped and the core 15 has one signal line, and the current flowing through the power line 11 is large, the core with the large wedge-shaped gap interval works. When a signal is injected and the current flowing through the power line is small, the core in the portion where the wedge-shaped gap is small works to inject more signals. Thereby, it can respond to the fluctuation | variation of a continuous electric current value.
The above embodiment is an example, and it is only necessary that the opposing end edges 15a and 15b constituting the notch are linear and face each other in a non-parallel state.

  FIG. 5 is a block diagram of an injection unit according to the fifth and sixth embodiments of the present invention. The injection unit 500 includes signal lines 24 and 25 for magnetically coupling signals via the cores 20 and 21, time measuring means (not shown) for measuring time, and signal line selection for selecting one of the signal lines 24 and 25. Unit 26, current value measuring means 22 for measuring a current value flowing through the power line 23, and a control unit 28. Note that the timing means can be obtained by counting clock signals in the control unit 28, and the current value measuring means 22 may be provided inside.

  First, as a fifth embodiment, when superimposing a signal on the power line 23, the control unit 28 selects a signal line by the signal line selection unit 26 according to the time measured by the time measuring unit, and transmits a signal to the selected signal line. Supply. FIG. 6 is a flowchart for explaining this operation in more detail. The value of the current flowing through the power line 23 varies depending on the time zone. For example, in a housing complex such as a condominium, the current value varies greatly between morning, noon, night, and midnight, and the tendency does not change significantly throughout the year. Therefore, in the present embodiment, such a tendency is grasped in advance, a current value in each time zone is assumed, and a signal line corresponding to the current value is selected. That is, the control unit 26 determines whether the switching time of the core 20 having a large gap interval has been reached by the internal timing means (S1), and if it is not that time (NO route in S1), switches to the core 21 having a small gap interval. (S2), a large amount of signal is injected into the signal line 25 (S3), and the process returns to step S1 and is repeated. On the other hand, when the switching time of the core 20 having a large gap interval is reached in step S1 (YES route in S1), the core 20 having a large gap interval is switched (S4), and a small amount of signal is injected into the signal line 24. (S5) Return to step S1 and repeat. Thereby, it is possible to select an optimum core for a current change that varies with time by a simple method. In addition, what is necessary is just to add an annual calendar function to a time measuring means, when the electric power usage form for every season changes by use of air conditioning etc.

  Next, as a sixth embodiment, when superimposing a signal on the power line 23, the control unit 28 selects and selects a signal line by the signal line selection unit 26 according to the current measured by the current value measuring unit 22. A signal is supplied to the signal line. FIG. 7 is a flowchart for explaining this operation in more detail. In this embodiment, while measuring a current value, a signal line is selected so as to select a core having a gap interval of a notch that is optimal for the current value, and a signal is supplied to the signal line. That is, the control unit 26 determines whether or not the current flowing through the power line 23 exceeds a predetermined value based on the signal 27 from the current value measuring means 22 (S11), and if not (NO route in S11). Switching to the core 21 having a small gap interval (S12), injecting a large amount of signal into the signal line 25 (S13), the process returns to step S11 and repeats. On the other hand, if the current has exceeded in step S11 (YES route in S11), the core 20 having a larger gap interval is switched (S14), a small amount of signal is injected into the signal line 24 (S15), and the process returns to step S11. And repeat. Thereby, an optimal core can be selected according to the magnitude of the current value regardless of the time zone.

  FIG. 8 is a diagram showing a specific shape of the core. In order to pass the power line through the cylindrical core, it is necessary to remove the already disposed power line and penetrate the core. Therefore, in general, two cores having a substantially semicircular (U-shaped) cross section are used. Used in combination. For example, as shown in FIG. 8, two second cases 32 are alternately arranged in a first case 31 that can accommodate the core 30, and the first case 31 and the second case 32 are hinged 34. Are combined. One core 30 is accommodated in the second case 32.

FIG. 9 is a diagram illustrating a method of providing a gap in the core. FIG. 9A is a development view, and FIG. 9B is a cross-sectional view. As shown in FIG. 9A, after the core 30 is accommodated in the first case 31 and the second case 32, the spacers 37 for forming gaps in the cores of the first case 31 are end edges. Affix to the part. In addition, a spacer 38 for forming a different gap in each core of the second case 32 is attached to the end edge portion. By varying the thickness of the spacer, the gap of the core can be varied. 9B, the power line 60 and the signal line 61 are passed through the center of the core 30, and the second case 32 is rotated around the hinge 34 so as to cover the first case 31. The stopper 36 is fixed by engaging with the engaging hole 35.
If the cases as shown in FIG. 8 and FIG. 9 are prepared as described above, the construction for installing the core on the power line becomes easy, and variations due to the skill of the operator do not occur.

As described above, according to the present invention, the cores 1 and 3 have a loop shape having the notches 6 and 5 in a part thereof, and the gap intervals between the notches 6 and 5 are different from each other. A core that is not magnetically saturated can be used in accordance with the magnitude of the current value flowing through.
In addition, since the orientations of the cutout portions of the cores 1 and 3 are arranged at angles different from each other by 90 degrees or more, preferably 180 degrees, interference between adjacent cores can be minimized.
In addition, when superimposing a signal on the power line 23, the control unit 28 selects a signal line by the signal line selection unit 26 according to the time measured by the time measuring unit and supplies a signal to the selected signal line. It is possible to select an optimum core for a current change that varies with time by the method.

Further, when the time measured by the time measuring means is a time zone in which the current value flowing through the power line 23 is large, the control unit 28 selects the signal line of the core 20 having a large gap interval between the notches, and the time zone in which the current value is small. In this case, since the signal line of the core 21 having a small gap interval between the notches is selected and a signal is supplied to the selected signal line, an optimum core according to the current value can be selected.
In addition, when the signal is superimposed on the power line 23, the control unit 28 measures the current value flowing through the power line by the current value measuring unit 22, selects the signal line by the signal line selection unit 26 according to the measured current value, Since a signal is supplied to the selected signal line, an optimum core can be selected depending on the magnitude of the current value regardless of the time zone.

Further, when the current value measured by the current value measuring unit 22 exceeds a predetermined value, the control unit 28 selects the signal line of the core 20 having a large gap interval between the notches, and the current value becomes the predetermined value. If it falls below, the signal line of the core 21 with a small gap interval between the notches is selected and the signal is supplied to the selected signal line, so that the optimum core can be selected depending on the magnitude of the current value regardless of the time zone. it can.
In addition, since the injection unit 300 includes the core 12 having a notch having a stepped gap gap, and the signal line 17 that magnetically couples the signal through the core 12, one signal line 17 is provided. Therefore, an optimum signal amount can be injected regardless of the magnitude of the current.
In addition, the injection unit 400 includes the core 15 having a wedge-shaped notch with a gap interval and the signal line 18 that magnetically couples the signal through the core 15, so that a continuous current value is obtained. Can respond to fluctuations.

(A) is an external view of the schematic block diagram which shows a part of injection part which concerns on the 1st Embodiment of this invention, (b) is a schematic diagram. (A) is an external view of the schematic block diagram which shows a part of injection part which concerns on the 2nd Embodiment of this invention, (b) is a schematic diagram. (A) is an external view of the schematic block diagram which shows a part of injection part which concerns on the 3rd Embodiment of this invention, (b) is a schematic diagram. (A) is an external view of the schematic block diagram which shows a part of injection part which concerns on the 4th Embodiment of this invention, (b) is a schematic diagram. It is a block diagram of the injection part which concerns on the 5th, 6th embodiment of this invention. It is a flowchart explaining the 5th Embodiment of this invention in more detail. It is a flowchart explaining the 6th Embodiment of this invention in more detail. It is a figure which shows the specific shape of a core. It is a figure explaining the method of providing a gap in a core, (a) is an expanded view, (b) is sectional drawing. It is a figure explaining the method of injecting using the conventional ferrite core. It is a conceptual diagram of the TT system employ | adopted as the power distribution system of Japan.

Explanation of symbols

  1, 3 cores, 2 intervals, 4 power lines, 5, 6 notches, 7, 8 signal lines, 100 injection parts

Claims (5)

A power line communication system for transmitting and receiving signals by superimposing a high frequency signal on a power line,
An injection unit for superimposing a signal to be transmitted to the power line and extracting a signal to be received;
The injection unit includes two cores ,
Each of the cores is a cylindrical body that engages with the outer periphery of the power line, and includes a notch portion extending in the axial direction in a part thereof, and the gap intervals of the notch portions are different from each other ,
The power line communication system according to claim 1, wherein the injection part is obtained by relatively shifting the circumferential position of the notch part of each core by 90 degrees or more . A power line communication system for transmitting and receiving signals by superimposing a high frequency signal on a power line,
An injection unit for superimposing a signal to be transmitted to the power line and extracting a signal to be received;
The injection unit includes at least two cores,
Each of the cores is a cylindrical body that engages with the outer periphery of the power line, and includes a notch portion extending in the axial direction in a part thereof, and the gap intervals of the notch portions are different from each other,
A signal line that is magnetically coupled to the power line via each core, a time measuring unit, a signal line selection unit that selects the signal line, and a control unit;
The control unit, when superimposing a signal on the power line, selects the signal line by the signal line selection unit based on the time measured by the time measuring means, and supplies the signal to the selected signal line. A power line communication system. When the control unit detects that the current value flowing through the power line increases, the control unit selects a core signal line having a large gap interval between the notches, and the current value decreases. 3. The power line communication system according to claim 2, wherein, when it is detected, a core signal line with a small gap interval between the notches is selected, and the signal is supplied to the selected signal line . A power line communication system for transmitting and receiving signals by superimposing a high frequency signal on a power line,
An injection unit for superimposing a signal to be transmitted to the power line and extracting a signal to be received;
The injection unit includes at least two cores,
Each of the cores is a cylindrical body that engages with the outer periphery of the power line, and includes a notch portion extending in the axial direction in a part thereof, and the gap intervals of the notch portions are different from each other,
A signal line that is magnetically coupled to the power line via each core; a current value measuring unit that measures a current value flowing through the power line; a signal line selection unit that selects the signal line; and a control unit,
When the signal is superimposed on the power line, the control unit measures a current value flowing through the power line by the current value measuring unit, and selects a signal line by the signal line selection unit according to the measured current value, A power line communication system , wherein the signal is supplied to the selected signal line . When the control unit determines that the current value measured by the current value measuring unit exceeds a predetermined value, the control unit selects a core signal line having a large gap interval between the notches, and the current value is a predetermined value. 5. The power line communication system according to claim 4, wherein when it is determined that the value is less than the value, a core signal line having a small gap interval between the notches is selected, and the signal is supplied to the selected signal line. .

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