JPS6057253B2 - Signal transmission method using power lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal transmission system using a power line, and its purpose is to miniaturize and configure a signal leakage prevention filter, and to reduce the SN ratio of the signal transmission system. It is an object of the present invention to provide a signal transmission method using a power line that can reduce power consumption and improve system reliability.

FIG. 11 shows an example of signal transmission using conventional power line carriers.

In Figure 11, 10 is the lead-in AA cable, Bo is the limiter, F is the AA filter for preventing signal leakage, A is the distribution board, and Ku to B5 are the protective breakers for branch circuits 1, 1, and 1, respectively. In this conventional example, 11 and 15 are lighting circuits, 12 and 14 are 100V outlet branch circuits, and 1a is a 200V exclusive outlet branch circuit. Furthermore, in FIG. 11, R,...,R,3,R2,,R. ,,R.
2, R, O are carrier signal transmitters, T22, T.

, , T52 is a carrier signal transmitter, Cl, C2, , Cs, .
Co,,C. . is the plug outlet part, L, , L
1291439lj219L53 is lighting load, L219
Lf319L42 is an outlet load. In the case of signal transmission using indoor power line carrier with the configuration shown in Fig. 11, power transmission and signal transmission are carried out using two-core power lines a and c. The relationship between the signal and the noise level will be discussed with reference to FIG. In FIG. 12, S is a commercial power supply source, Tj
is a transmitter, Rk is a receiver, CtJ and Crk are coupling capacitors (LC resonant couplers may also be used), Ltj, Lr
k indicates a coupling transformer, and Li is a high-noise, low-impedance load connected between power lines a and c. Further, arrows on the line indicate the direction in which high-frequency current flows, and solid lines and broken lines indicate noise current and signal current, respectively.
In the conventional wiring system shown in Fig. 12, the noise current and the signal current flow so as to interfere with each other as shown in the figure, and the signal current flows into the low impedance load Li, so the signal to the receiver Rk is attenuated, and as follows: The level relationship is as explained in FIG. 14. In other words, according to Chapter 1, Section 186 of the Electrical Equipment Technical Standards and Internal Line Regulations, the permissible limit for high-frequency current leaking into other electrical lines in the frequency band of 330KH2 or less, based on the measurement method shown in Figure 13, is as follows: 1mw to 0d
It is specified that B is -3 (b) (1 μw) or less. In Fig. 13, W is an electrical machine device that uses high frequencies, L is a choke coil used as a device with high impedance in a high frequency band, HPF is a high-frequency p-wave filter for blocking 60Hz or 50Hz, and LM is an impedance of 7.
The 5Ω selection level meter, MT, is a matching transformer with primary 16Ω and secondary 75Ω, and when other high frequency equipment is connected to power lines A and c, if the signal leakage level between the lines is below Lp. good. That is, an appropriate signal leakage prevention filter F is required so that the Lp level shown in FIG. 13 satisfies this value or less. Now, the transmitter (T22, T, l, T52 in the circuit of Figure 11, TJ in the circuit of Figure 12)
etc.), the signal level sent out from the SPl receiver (11th
In the circuit shown in the figure, the reception level of Rll, Rl3... Rk in the circuit shown in Figure 12) is RP1, and the noise level generated from the load equipment Li, etc. of the indoor power line is NP.In general, indoor power lines use low impedance. Since there are a large number of load devices shown in
The noise level Np is quite high because the signal attenuation in the signal path leading to k is large and there are many noise generating loads Li with high noise levels. An example showing such a relationship is shown in FIG. 14. From the above, in order to satisfy the condition that signal reception level Rp>noise level Np, the reception level Sp is required to have a fairly high value. Therefore, the high level transmission signal,
In order to lower the signal to the regulation value level Lp level, a filter F having a large signal leakage prevention characteristic as shown in FIG. 14 (Sp above p) is required. However, the shape of such a filter F becomes extremely large as the (Sp above p) level increases, and a large space is required in the distribution board A, which increases the overall cost. If you want to transmit over a wide frequency band, use broadband. area,
Although filter characteristics with high attenuation are required, Filter F
The current value of the commercial frequency current flowing through the line is large, for example 60A for AA batteries, so the coils inserted into the line become large, making it impossible to design them with practical dimensions. The present invention has been provided in view of the above points, and aims to provide a new indoor signal transmission method that overcomes the drawbacks of the conventional signal transmission method using indoor power line carriers and enables wiring at the same electrical construction level. An example of its configuration is shown in FIG.

All the symbols in FIG. 1 correspond to the conventional example shown in FIG. 11, but the difference is that the power cable line is composed of three cores. In the embodiment shown in FIG. 1, power is supplied along the solid line, and the broken line is used as one of the signal lines. Examples of cross-sectional views of three-core power supply paths are shown in FIGS. 4 to 7.

Figure 4 shows a 3-core VVF cable, Figure 5 shows a 3-core cab tire cable, Figure 6 shows a 3-core rail-shaped wiring duct, and Figure 7 shows a 1-core B line of the VVF cable used for signal transmission. A line segment connecting two power core wires A and c (X
The signal core wire b is placed on the perpendicular bisector (on the Y-axis passing through the midpoint 0) of It is. Figure 2 shows an example of signal transmission and reception when using such power lines (three-core A, b, and c lines), and the embodiment in Figure 2 corresponds to the conventional example in Figure 12. Below, this second
The relationship between the level of a signal and "noise" will be explained using an example in the figure. In FIG. 2, S is a commercial power supply source, Tj is a transmitter, Rk is a receiver, Ctjl, Ctj2, and Crk.
2 are coupling capacitors, and one of the signal output terminal of the transmitter TJ and the signal input terminal of the receiver Rk is connected to the power core wire a and c through the coupling capacitors Ctjl, Cti, and Crkl, Crk2, respectively. connected to each line. Instead of these capacitors, an LC resonant coupler may be used as the coupling part. Also, as in the case of the circuit in Figure 12, Li indicates a high-noise, high-impedance load connected between power lines A and C, and the arrows on the line indicate the direction in which high-frequency current flows, and the solid line in the figure and broken lines indicate the flow of noise current and signal current, respectively. Thus, in Figure 2, commercial power is passed between lines A and c, and
When a signal is passed through a coupling part between the line and the A, c line, the coupling capacitors Ctjl, Ctj2 and C that constitute the coupling part are
By selecting the same values for rkl and Crk2,
As shown in the figure, substantially equal signal currents in the same direction flow through the A and c lines, and almost no leakage potential of high-frequency signals occurs between the A and c lines. In addition, by placing the b line on the perpendicular bisector of the line connecting the A and c lines, the noise current induced into the b line by the commercial power currents flowing in the A and c lines in opposite directions is canceled. Noise current no longer flows through the signal extraction paths inside the transceivers Tj and Rk. The relationship between the signal and noise level at this time is shown in FIG. However, the third
In the figure, the Sp level is the received signal level applied between the A, C lines and the B line, Rp is the received signal level, and Np is the level of the received signal applied between the A, C lines and the B line due to the asymmetry of the electric line or the difference in coupling capacitor value. For the same reason, the noise level Sp'' induced during A
The signal leakage level Lp induced between the , c lines is the same legal regulation level as shown in FIG. In the transmission system according to the present invention, the A, c and b lines are arranged symmetrically (the b line is arranged on the perpendicular bisector of the line connecting the A and c lines) so that induced noise is canceled. Since the noise level Np in the signal line is lowered, the signal transmission level Sp may be lowered, and furthermore, the signal currents flowing in the A and C lines, which are the power lines, are approximately equal and in the same direction. , the voltage drop due to line impedance is equal, so A
, the signal leakage voltage generated between the C lines becomes almost 0, and the A,
The c line can be regarded as one signal line. Therefore, the signal leakage level Sp'' to the power line becomes extremely small, and the level difference (p above Sp'') between this signal leakage level Sp'' and the legal regulation level Lp becomes extremely small.As described above, Since the signal transmission level Sp can be made small, and the signal leakage level Sp'' can be made extremely small, the attenuation characteristics of the signal leakage prevention filter F can be obtained with an extremely small and inexpensive configuration, and become unnecessary in some cases. Furthermore, transmission over a wide frequency band is possible. On the other hand, the wire cost and wiring cost for such 3-core cables and 3-core rail-shaped wiring ducts are not so much compared to 2-core cables and 2-core wiring ducts, and the overall cost including the signal leakage prevention filter F is The system cost can be realized at a lower cost than that of a two-core power line transmission system. In addition, there are many cases where a dedicated communication line is separated from the power line as a signal transmission path, but in this case, the wiring work for the communication line is
? This method is performed separately from the wiring work for cables, etc.), and requires a separate dedicated wire material, so there is a problem that the wiring cost is considerably higher than in the case of the present invention. In addition, in the above explanation, the case where a 3-core power line is used was described, but 4-core power line is used.
Similar effects can be expected in the case of multi-core power lines.

That is, FIG. 8 shows an example of a four-core power line, where a shows a flat VVF cable, b shows a core captire cable, and C shows a four-core duct. The example circuit in FIG. 9 is A
, d-core wires from the power source S1, and another power source S2 between the B and c-core wires (Ad)-(Bc
) is an example in which signals are sent and received via a coupling capacitor. Further, FIG. 10 shows that while signals are transmitted and received between (Ad) and (Bc), signals are also transmitted and received between the transmitter Tdj and the receiver Rdk between the B and C core wires, which are independent communication paths. In this embodiment, two independent systems of signal transmission are possible. In this way, a 4-core system can have more functions than a 3-core system. By the way, in the embodiment shown in FIG. 8B and c, the two lines forming the signal transmission path are connected to A and d, respectively.
It is constructed using lines B, C, and C, and operates in the same way as the embodiments shown in FIGS. 1 to 7.

For example, when the circuit shown in Figure 9 is implemented using the 4-core duct shown in Figure 8c, the transceivers Tj and Rk are connected to the power lines A, d, B, and c through substantially the same coupling parts, respectively. Therefore, substantially equal signal currents in the same direction flow through the pair of A, b lines and B, c line, respectively, and the voltage drop due to line impedance becomes equal, so that each power line A, Almost no signal current leakage occurs to the d line, B line, and c line. On the other hand, inductive noise occurs in the A and d lines due to the commercial power current flowing in the B and c lines, and inductive noise occurs in the B and c lines due to the commercial power current flowing in the A and d lines. When viewed as signal lines, the A, d lines and B, c lines exist at their respective center lines (0 and O'').
It can be regarded as a real line, and the induced noise caused by the commercial power current generated in the A, d, B, and c lines is canceled in the same way as in the embodiments of FIGS. 1 to 7. In other words, since the a and d lines and the b and c lines are equivalent signal lines (the transceivers Tj and Rk are connected through approximately the same coupling part), the A, d lines and the B, c lines can be considered as one track. In the figure, the x-axis is A,
The axis passing through the d line, the x″ axis is B, the axis passing through the c line, the Y axis is A,
There is a perpendicular bisector of the line segment connecting the d line, B line, and c line. As described above, the present invention uses at least two cores of a power line using a multicore power cable with three or more cores or a multicore rail-like wiring duct as a power supply line for first-class loads, and connects other core wires and By connecting one of the signal output end of the transmitter and the signal input end of the receiver to both power core wires through substantially the same coupling part, both The power system and the signal system can be connected by allowing substantially equal signal currents in the same direction to flow through the power core wires, and by arranging the other core wires on the perpendicular bisector of the line connecting both power core wires. Since they do not interfere with each other, construction can be performed at the same level as conventional power and electrical work, and a signal transmission system with low system cost can be obtained without the need for dedicated communication lines.
Connect one of the signal output end of the transmitter and the signal input end of the receiver to both power core wires through substantially the same coupling part,
Since both power core wires form one line of the signal transmission path, the core wires can be used effectively and costs can be reduced.Furthermore, the signal currents sent and received by the transceiver can be transmitted and received at approximately the same level. Since the signal current is made to flow through both power core wires through the coupling part, and the signal current is approximately equal and in the same direction through both power core wires, a leakage potential due to the signal current does not occur in both power core wires. This has the effect of reducing the size and cost of the signal leakage prevention filter.
Furthermore, since the signal core wire is placed on the perpendicular bisector of the line that connects both power core wires, the signal line is formed in equilibrium with the power line, allowing signal transmission from the power system. The noise induced into the system is canceled and the SN of the signal transmission system is reduced.
The advantages are that the ratio is high, reliability is high, and broadband transmission is possible.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram of an embodiment of the present invention, Fig. 2 is a main block circuit diagram for explaining the operation of the same as above, Fig. 3 is a characteristic diagram of signal and noise levels in the same as above, and Figs. 7 is a cross-sectional view showing different examples of the three-core power line used in the present invention, FIGS. 8A, b, and c are cross-sectional views showing different examples of the four-core power line used in the present invention, and FIGS. Fig. 10 is a block circuit diagram of a wiring example when using the 4-core power line of the present invention, Fig. 11 is a block circuit diagram of a conventional example, and Fig. 12 is a main part block circuit diagram for explaining the operation of the same. , FIG. 13 is an explanatory diagram of a high frequency signal level measurement method on a line, and FIG. 14 is a characteristic diagram of signal and noise levels in the conventional example.

Claims (1)

[Claims] 1. Use at least two cores of a power line using a multicore power cable or multicore rail-like wiring duct with three or more cores as a power supply source for general loads, and use other core wires and power core wires. Transmission and reception of high-frequency signals is performed, and one of the signal output end of the transmitter and the signal input end of the receiver is connected to the two power core wires through substantially the same coupling part, so that the core wires are almost equal to the two power core wires. The power system and the signal system are prevented from interfering with each other by ensuring that signal currents flow in the same direction and by arranging the other core wire on the perpendicular bisector of the line connecting both power core wires. A signal transmission method using power lines that is characterized by: