JPS607460B2 - Indoor power line transport system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In a carrier control system using indoor power lines, the present invention provides a filter F that blocks carrier waves at each branch position of a plurality of power branch lines 1, 12, . . . for transmitting and receiving signals. ．． ...F
n and each filter F.n. . . . On the load side from Fn, power branch lines 1, . . . ln are connected to relay amplifier D, and any of the power branch lines 1. . . . The signal transmitted from the transmitter L2 on the power branch line 1. This is an indoor power line carrier system that is characterized by transmitting signals to ln, and its purpose is to improve the S/N ratio by reducing signal attenuation caused by load equipment, and to improve the reliability of signal transmission and reception. An object of the present invention is to provide an indoor power line transportation system with improved performance.

An example of a conventional signal transmission system using power line transport is shown in FIG.

In the circuit shown in Figure 1, lo is the lead-in AA cable, Bo is the current limiter, F is the AA filter for preventing signal leakage, and C
o is a coupling capacitor, To is a transformer whose intermediate tap is connected to the ground line of the power system, and these coupling capacitor Co and transformer To constitute a signal crossover circuit. Furthermore, A is the distribution board, B, ~B are the protective playing forces of each power branch line 1, ~15, respectively, and the power branch line 1
, to 15 are, for example, power branch lines 1, , 15 are lighting circuits, power branch lines 12 and 14 are 100V outlet circuits, and power branch line 13 is a 200V exclusive outlet circuit. Also R
、． , R, 3, R2,, R phantom, R42, R53 are carrier signal receivers, T Shigeru, L, , T52 are carrier signal transmitters, C2,, C22, C3,, C4, ,C
42 is the plug outlet part, L,, L2, L, 3, L5,
, L53 is a lighting load, and L, , L42 is an outlet load. Consider, for example, a case where a signal is sent from the transmitter L2 to the receiver R42 to control the outlet load L2 using the conventional circuit configuration shown in FIG.
At this time, the signal output from the transmitter T is transmitted from the power branch line 12 to the coupling capacitor Co and transformer To that constitute the signal crossing circuit, the play force B4, and the power branch line 1.
40 and is received by the receiver R42, but in reality, there are low impedance load devices such as large-capacity heaters, resonant load devices that resonate in the carrier frequency band, etc. on this signal path. In addition, the loads on the other power branch lines 1, 13, and 15 are connected in parallel within the distribution board A, and a crossover circuit section is configured by a coupling capacitor Co and a transformer To. Crossover loss due to coupling capacitor Co (coupling capacitor Co in series)
input, signal attenuation occurs due to the impedance of this coupling capacitor Co. ) etc., significant signal attenuation may occur when this transmitted signal reaches receiver R42. At this time, if there is a noise generating device near the receiver R42, there is a problem that the signal-to-noise ratio (S/N) during reception becomes extremely poor, making it impossible to reproduce the correct signal. In other words, in such a system, there may be cases where control that requires reliability cannot be performed, and therefore increasing the signal level to be sent out will reduce the outdoor signal leakage level according to the draft of Electrical Equipment Technical Standards 3. Due to strict regulations (
The permissible amount is less than 1 French watt), and the shape of the leakage prevention filter becomes extremely large, which poses a problem in practical use. The present invention has been provided in view of the above points, and one embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an example of the configuration of the present invention, and shows F, ~F
Each symbol other than 5 and D corresponds to the conventional example in FIG. An example of its configuration is shown in FIG. In the circuit shown in Figure 5, the left side shows the distribution board side, and the right side shows the power branch line side.The LC parallel resonant circuit has high impedance in the block frequency band, and the LC series resonant circuit has low impedance in the flock frequency band. This prevents signal leakage to the distribution board. Note that the filter Fo in the conventional circuit shown in FIG. 1 can also be considered to have a similar configuration. D is a signal relay amplifier,
This embodiment has a built-in synchronizing signal generator, and an example of the configuration of this repeater amplifier D is shown in FIG. In Fig. 3, 1, ~ln are power branch lines, C
, ~Cn are coupling capacitors, TR, ~TRn are transformers, E, ~En are buffers, and TR is a transformer for taking out any one of the output signals of E, ~En. As shown, signals of the same frequency are temporally 3
Therefore, two or more signals of the same frequency do not exist at the same time as the outputs of the buffers E, -Bn. (It is possible that signal outputs of different frequencies exist at the same time.) In the circuit shown in Fig. 3, G is a demodulation circuit, and G2 is a demodulation waveform signal detection circuit 4, which detects, for example, the time position of a reproduced pulse or the inside of the pulse. This is the part that detects the correct signal. Furthermore, G3 is a memory circuit for reproducing signals using a shift register, etc., G5 is a synchronization timing circuit that takes synchronization timing with the AC phase of the power line and generates synchronization pulses,
G4 synchronizes and modulates the synchronization pulse from the synchronization timing circuit G5 and the memory signal from the memory circuit G3 with the power line phase, and connects it to the power branch line 1 via transformers TR, ~TRn and coupling capacitors C, ~Cn. , ~ ln. A portion D surrounded by a broken line corresponds to the relay amplifier D of the circuit in FIG. Next, FIG. 4 shows a time chart of the control system of the above embodiment.

The time chart in FIG. 4 shows an example of pulse amplitude modulation in a power-synchronized time division multiplex system. In this embodiment, the power line power supply waveform as shown in FIG.
The synchronization signal and each channel control (or display) signal are temporally arranged by cyclically distributing the signals. Therefore, the time position of each channel can be known by counting the power cycle from the synchronization signal position. Also, each channel is A, , for the reason described later.
It is divided into A2, . . . time period and B, , &, . . . time period. Figure b shows a signal transmission gate obtained in synchronization with the power line power waveform a, figure c shows the carrier signal waveform superimposed on the power line, and d shows the demodulated reproduction pulse waveform. For example, let's consider the first channel CH-1 control.
Let us consider a case where a control signal is sent to the load L42 to control the load L42. When the synchronization signal (carrier signal within the synchronization time zone SYN) is sent from the relay amplifier D during the time period to, ~ and 2, the next power supply voltage zero phase point 2 will be the center, for example, when performing ON control. Control signals are placed at earlier positions in time, and when off control is performed, at later positions. In the illustrated example, the first channel is placed at times t, . . . in the case of on control. ~t,2
The second channel sends out a control signal in the A2 time period from time t2 to t22 in an off control example, and the third channel shows a state in which no control signal is sent out. ing. Now, the ON signal from the transmitter T22 is output at a certain time, . When sent in the interval (A, time period) ~t,2, this carrier signal is transmitted through the power branch line 12, via the coupling capacitor C2, the transformer TR2, the buffer E2, and the transformer TR, and is demodulated by the demodulation circuit ○. , the pulse position and pulse of this demodulated signal are verified by the signal detection circuit C2, and once it is determined that the signal is correct, this information signal is stored in the memory circuit ○3, and the position and time before the next drop phase point is determined. In the section 3-t, 4 (B, time period), transformer TR, TRn,
The signal transmitted via the coupling capacitors C, to Cn and transmitted through the power branch line 14 is received by the receiver R42. In this case, the filters F and ~F5 in Fig. 2 are configured as shown in Fig. 5, and the impedance seen from the power branch line side is L.
Due to high impedance due to C parallel resonance,
Unlike the conventional example, there is no negative effect of signal attenuation depending on the load connected to other lines, and only the signal attenuation due to the load in each power branch line needs to be considered, so signal attenuation can be extremely minimized. In addition, since signal verification and amplification are performed in the relay amplifier D, extremely reliable signal transmission can be achieved. In actual experiments, an improvement in signal attenuation of approximately 5 MB (at a carrier frequency of 100 KHz) was obtained, indicating that high-quality signal transmission is possible even on power lines with adverse conditions such as high noise and high signal attenuation. I am getting .
In the circuit shown in Figure 2, transmitters/receivers and filters F, ~F5 are connected to all the power branch lines, but for example, when transmitting signals only through the outlet circuit branch lines 12~14, the lighting circuit filter There is no need for connection lines between F and F5 and relay amplifier D, and if a method is found in which the filters F and F5 are superimposed near the drop phase as shown in Fig. 4,
Generally, in the vicinity of zero phase, the current value is small, so the coil constituting the parallel resonant circuit shown in FIG. 5 can be constructed in a small size, so it can be said that this is a practical method that is extremely easy to implement. In the above embodiment, an example of pulse amplitude modulation was described to simplify the explanation, but it is also possible to use frequency modulation or phase modulation.
Alternatively, it is of course possible to encode pulses to increase the redundancy of control signals and increase the variety of control signals, and it is also possible to increase the number of carrier frequency channels by transmitting multiple frequencies in the same time period. It is also possible to increase the multiplicity. This idea can also be applied to general communication systems that extend radially using the principles of the same aircraft. As described above, the present invention receives a signal transmitted from a transmitter on a power branch line by a relay amplifier, demodulates and reproduces it, and then delays the time and sends the same signal content from the relay amplifier to each of the power branch lines. In the indoor power line carrier system, a leakage prevention filter is provided at the branch position of each power branch line, and the load side of each power branch line is connected to the relay amplifier, so each transmitter This eliminates the need for devices connected to all power branch lines through the main power line to be connected in parallel as a load for the transmitted signal from the main power line or the retransmitted signal from the repeater amplifier, reducing signal attenuation. Moreover, since the signal level on the transmitting side does not have to be increased too much, the cost of the leakage prevention filter can also be reduced.

[Brief explanation of the drawing]

Fig. 1 is a circuit block diagram of a conventional example, Fig. 2 is a circuit block diagram of an embodiment of the present invention, Fig. 3 is a circuit block diagram of the repeating amplifier shown above, Fig. 4 is a time chart shown above, and Fig. 5 is a specific circuit diagram of the same filter as above, 1 to 15 are power branch lines, D is a relay amplifier, and core 2 is a transmitter. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 In a carrier control system using indoor power lines, a filter is inserted to cut off the carrier wave at each branch position of multiple power branch lines that transmit and receive signals, and the power branch lines are connected to a relay amplifier on the load side of each filter. Then, the relay amplifier receives the signal transmitted from the transmitter on one of the power branch lines, demodulates and reproduces it, delays the time, and sends the same signal content from the relay amplifier to each of the above power branch lines. An indoor power line transport system characterized by: