JP4251880B2 - Distribution line carrier signal transmission method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distribution line carrier signal transmission method in which a load control system using distribution line conveyance and a unidirectional data transmission system using distribution line conveyance are adjacently operated independently.
[0002]
[Prior art]
In general, transmission (injection) of a signal to a distribution line in a distribution line transfer system using a single-phase low-voltage distribution line is performed between lines of 100V or 200V. The configuration of such a single-phase low-voltage distribution line conveyance system will be described with reference to FIG.
[0003]
In the single-phase low-voltage distribution line conveyance system, a signal transmission source 50 is connected via a coupler 51 between low-voltage distribution lines 30a and 30b to which a load 40 is connected, and a receiver 52 is provided at a point away from the signal transmission source 50. Connected and configured. The low voltage distribution line 30 is connected to a high voltage distribution line 37 via a transformer 35.
[0004]
When such a low-voltage single-phase distribution line conveyance system is used adjacently in a plurality of low-voltage distribution systems, if the impedance of the high-voltage distribution line at the signal frequency is large, signal leakage via the adjacent transformer 35 occurs. Then, there is a possibility of mutual interference between adjacent low voltage distribution systems.
[0005]
In addition, in the low-voltage distribution line carrier signal transmission path system, it has been proposed to perform signal transmission using the ground contact system. In this method, the signal voltage transmitted from the signal source is applied between the low-voltage distribution line and the ground through a filter that passes a frequency signal without passing through the commercial frequency, and is transmitted through the low-voltage distribution line and received through the filter. (For example, see Patent Document 1)
[0006]
In addition, in single-phase three-wire line-to-line low-voltage distribution line transportation, a signal source is inserted in the red phase or black phase, a capacitor is inserted between the red phase and black phase, and red is transmitted by signal transmission from the signal source. It has been proposed to prevent a decrease in the received signal level at the terminal by eliminating a voltage drop due to the line impedance of the ground line of the distribution line by injecting signals into both phases and black phases. (For example, see Patent Document 2)
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 62-235829 (FIG. 3)
[Patent Document 2]
Japanese Patent Laid-Open No. 10-208184 (FIG. 1)
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art as described above, and when there is a low-voltage distribution line conveyance system that uses distribution line conveyance that operates independently in an adjacent low-voltage distribution line system. It is an object of the present invention to obtain a system capable of suppressing the mutual interference of independent system signals and performing stable operation.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a distribution line carrier signal transmission method in a distribution line carrier system that uses a line between single-phase three-wire low-voltage distribution lines as a signal transmission line. The signal having the same phase and level is transmitted to the voltage lines at both ends with respect to the neutral line, and the signal is detected between the neutral line and one of the voltage lines on the receiving side. As a result, mutual interference between independent systems due to signal leakage from the low-voltage distribution line to the high-voltage distribution line was suppressed.
[0010]
In the above distribution line carrier signal transmission method, the present invention detects each signal superimposed from the voltage line for injecting the signal, and detects the phase and level difference of the signal between the voltage lines each time the signal is transmitted. The difference between the phase and level of both signals at the next transmission is controlled to the minimum.
[0011]
The present invention relates to a signal transmitter that constitutes a distribution line transport system that uses a line between low-voltage distribution lines of a single-phase three-wire system as a signal transmission line, and includes a signal generator, a neutral line, and one voltage line. A first coupler that sends a signal between the lines and a second coupler that sends a signal between the neutral line and the other voltage line are provided between the neutral line and the one voltage line. In addition, signals having the same phase and the same level are transmitted between the neutral line and the other voltage line.
[0012]
Furthermore, the present invention provides the first signal detection circuit for detecting a signal superimposed on one voltage line and the second signal detection circuit for detecting a signal superimposed on the other voltage line in the signal transmitter. To detect the phase and level difference of the signal between the voltage lines every time a signal is transmitted, and to control the output of the signal generator so that the difference in phase and level at the next transmission is minimized did.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The distribution line conveyance system to which the distribution line conveyance signal transmission method according to the present invention is applied is a system that utilizes the single-phase three-wire system in which the low-voltage distribution system supplies 100V and 200V, On the transmission side, the neutral phase is used as a reference to send out signals of the same phase and level to the voltage lines on both sides, thereby canceling the magnetic flux of the transformer and suppressing signal leakage to the high voltage side. Between the voltage line and one of the neutral lines.
[0014]
Hereinafter, the configuration of a distribution line conveyance system to which the distribution line conveyance signal transmission method according to the present invention is applied will be described with reference to FIG.
[0015]
The distribution line conveyance system to which the distribution line conveyance signal transmission method according to the present invention is applied includes a signal transmitter 1 and a signal receiver 2a connected to a low voltage distribution line 30 connected to a high voltage distribution line 37 via a transformer 35. And a signal receiver 2b.
[0016]
The signal transmitter 1 includes a signal generator 11, an amplifier 12, and a coupler 13. The coupler 13 includes a first coupling transformer 131a and a second coupling transformer 131b.
[0017]
One end of the primary winding 131pa of the first coupling transformer 131a is connected to one output terminal of the amplifier 12 via the coupling capacitor 132a, and the other end is connected to the other output terminal of the amplifier 12. The secondary winding 131sa of the first coupling transformer 131a has one end connected to the voltage line 30a via the coupling capacitor 133a and the other end connected to the neutral line 30c.
[0018]
One end of the primary winding 131pb of the second coupling transformer 131b is connected to one output terminal of the amplifier 12 via the coupling capacitor 132b, and the other end is connected to the other output terminal of the amplifier 12. The secondary winding 131sb of the second coupling transformer 131b has one end connected to the voltage line 30b via the coupling capacitor 133b and the other end connected to the neutral line 30c.
[0019]
The signal receiving device 2a has one end connected to the voltage line 30a and the other end connected to the neutral line 30c. The signal receiving device 2b has one end connected to the distribution line 30b and the other end connected to the neutral wire 30c.
[0020]
In the distribution line transport system having such a configuration, the signals Sa and Sb having the same phase and level are supplied to the voltage lines 30a and 30b on both sides with respect to the neutral wire 30c to the secondary winding 35s of the transformer 35. By sending the signal currents Isa and Isb in opposite directions, the magnetic flux generated by the signal current flowing through the secondary winding 35s of the transformer 35 can be canceled, and signal leakage to the high voltage distribution line 37 side can be prevented. Can be suppressed.
[0021]
According to the distribution line conveyance system of this embodiment, the magnetic flux generated by the signal output from the signal generator does not leak to the adjacent distribution line conveyance system via the transformer.
[0022]
In the distribution line transfer system, there may be a difference between the two signal voltages applied to the voltage lines of the transformer 35 due to the imbalance of the load connected between 100 V of the low voltage distribution line 30. The configuration of the distribution line transfer system in consideration of this load imbalance will be described with reference to FIG.
[0023]
This distribution line transport system is provided with signal detection circuits 14a and 14b that monitor the signals of the voltage lines 30a and 30b, monitors the signals on the voltage lines 30a and 30b, and based on the monitoring results, the signals Sa and Sb. By controlling the phase and level, signal leakage to the high voltage distribution line 37 side is minimized.
[0024]
This distribution line transport system
(1) Providing signal detection circuits 14a and 14b for detecting signals on the voltage lines 30a and 30b,
(2) The point that the signal generator 11 outputs two independent outputs Sa and Sb,
(3) The output Sa and Sb of the signal generator 11 are output to the first amplifier 12a and the second amplifier 12b, respectively.
(4) Every time a signal is transmitted, the outputs of the signal detection circuits 14a and 14b are input to the signal generator 11, the phase and level difference of the signal between the voltage lines is detected, and the signal generator 11 at the next transmission is detected. The point of controlling the difference between the phase and level of the outputs Sa and Sb of the
This is different from the distribution line transfer system of FIG. The other points are the same, and detailed description is omitted.
[0025]
According to this embodiment, due to the imbalance between the load connected to the voltage line 30a and the neutral line 30c and the load connected to the voltage line 30b and the neutral line 30c, the first transformer 131a Even if a difference in phase or level occurs in the signal output from the second transformer 131b, the difference can be canceled out, and leakage of the signal to the high-voltage distribution line side can be prevented.
[0026]
【The invention's effect】
According to the present invention, in a distribution line transfer system that uses a single-phase three-wire low-voltage distribution line as a signal transmission line, signals of the same phase and level are transmitted to the voltage lines on both sides with respect to the neutral line. Thus, signal interference between a plurality of adjacent low-voltage distribution lines can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a low-voltage distribution line transfer system according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of a low-voltage distribution line transfer system according to another embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration of a conventional low-voltage distribution line transfer system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Signal transmitter 11 Signal generator 12 Amplifier 13 Coupler 131 Transformer 132 Coupling capacitor 133 Coupling capacitor 14 Signal detection circuit 2 Signal receiver 30 Low voltage distribution line 30a, 30b Voltage line 30c Neutral line 35 Transformer 37 High voltage distribution line

Claims (2)

In a distribution line carrier signal transmission method in a distribution line carrier system that uses a line between single-phase three-wire low-voltage distribution lines as a signal transmission path,
On the signal transmission side,
Sending the same phase and level signal to the voltage lines at both ends with reference to the neutral line,
Detect each superimposed signal from the voltage line that transmits the signal,
Every time a signal is transmitted, the phase and level difference of the signal between each voltage line is detected, and the difference between the phase and level of both signals at the next transmission is controlled to the minimum.
On the receiving side,
A distribution line carrier signal transmission method characterized in that a signal is detected between a neutral line and one of the voltage lines. In a signal transmitter constituting a distribution line transport system that uses a line between single-phase three-wire low-voltage distribution lines as a signal transmission path,
A signal generator that outputs two independent signals,
A first coupler for sending one signal between a neutral wire and one voltage wire;
A second coupler for sending the other signal between the neutral line and the other voltage line;
A first signal detection circuit for detecting a signal superimposed on one voltage line;
A second signal detection circuit for detecting a signal superimposed on the other voltage line;
The two signals of the signal generator are in-phase and at the same level, and are output between the neutral line and one voltage line and between the neutral line and the other voltage line, respectively.
Every time a signal is transmitted, the first signal detection circuit and the second signal detection circuit detect the phase and level difference of the signal between the voltage lines so that the difference in phase and level at the next transmission is minimized. To control the output of the signal generator
A signal transmitter characterized by being configured as described above.

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