JPS6238033A - Information transmission system - Google Patents

Abstract

PURPOSE:To constitute a transmission circuit with a transformer and a switch by connecting the primary side of a signal injection transformer in parallel between a voltage line and neutral line and turning on/off the switch inserted to the secondary side at a high speed so as to send information. CONSTITUTION:The phase of a commercial frequency signal is detected by inputting the primary voltage of the signal injection transformer 10 whose primary side is connected between the voltage line 3 and the neutral line 4 to a phase detection section 12 in a remote control slave station 7 provided to the load side. When the phase detection section 12 detects a zero point of the commercial frequency signal, it is informed to a processing unit 13, which sends a switching signal in response to the transmission information synchronously with the commercial frequency to the switch 11 based on the signal from the phase detection section 12. That is, a half wave of the commercial frequency signal is used as one bit to apply synchronization and FS turning on/off the switch 11 at a high speed. Thus, a high frequency current having a waveform shown in solid lines flows through the neutral line 3 toward the power supply via the signal injection transformer 10.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to an information transmission system using a low-voltage power distribution system, and in particular to a method for transmitting information from a remote control slave station installed on the load side of the low-voltage power distribution system to a solid device installed on the power supply side. This is what I did.

[Prior art and its problems]

Conventionally, as this type of information transmission system, there are known a system using power distribution lines and a transmission system using communication lines. The distribution line transmission method transmits signals by superimposing high-frequency signals on the distribution line, but coupling capacitors are used to inject high-frequency signals into the distribution line or extract high-frequency signals from the distribution line. , an LC resonant circuit, a power amplifier, and other circuits are required. Furthermore, since high-frequency signals are injected into and extracted from high-voltage distribution lines, these circuits must have sufficient voltage resistance. For this reason, the conventional system using distribution lines has a problem in that it is difficult to downsize the device and reduce cost. Furthermore, the transmission method using communication lines has similar problems because it requires equipment such as a modem, and is also economically difficult because it requires construction work for laying communication lines.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide an information transmission system that can easily transmit information from the load side to the power source side of a low-voltage power distribution system, and that can also simplify and downsize the device.

[Key points of the invention]

The present invention connects a signal injection transformer in parallel between the voltage line on the load side and the neutral line (ground phase), or between the voltage line on the load side and a dedicated line that is grounded on the voltage side and installed along the system. A switch is inserted in parallel on the secondary side of the switch, and this switch is turned on and off at high speed in synchronization with the commercial frequency to flow a high-frequency FS signal current to the neutral line or dedicated line, and this current change is The signal is received by a signal extractor installed on the power supply side.

[Embodiments of the invention]

FIG. 1 is an explanatory diagram of a power distribution system configuration for implementing the information transmission system according to the present invention. In the figure, 1 is a high-voltage distribution line, 2 is a pole transformer, 3 is a voltage line of a low-voltage distribution line, 4 is a neutral wire (ground phase) of a low-voltage distribution line, 5 is a grounding wire, 6 is a solid device, and 7 is a remote control slave station, 8 is a signal extractor, 9 and 13 are processing devices, 10 is a signal injection transformer, 11 is a switch, 12
indicates a phase detection section. Note that the switch 11 can be configured with a transistor or the like. In such a configuration, in the remote control slave station 7 provided on the load side, the phase detection unit 12 detects the primary side voltage of the signal injection transformer 10 whose primary side is connected between the voltage line 3 and the neutral line 4.
to detect the phase of the commercial frequency. Phase detection section 1
2 notifies the processing device 13 of the detection of the zero point of the commercial frequency. Based on the signal from the phase detection section 12, the processing device 13 sends a switching signal according to the transmission information to the switch 11 in synchronization with the commercial frequency. That is,
As shown in FIG. 2, the commercial half wave is synchronized as one bit, and the switch 11 is turned on and off at high speed so that FS modulation is performed according to "1" and "0" of the transmission information. As a result, a high frequency current having a waveform as shown by a solid line in FIG. 2 flows through the signal injection transformer 10 toward the power supply side through the neutral wire 3. In the solid bag i1!6 provided on the power supply side, the signal extractor 8 attached to the neutral wire 4 detects the high frequency current from the load side and sends it to the processing device 9.
The processing device 9 determines transmission information from the ps modulated signal. This enables information transmission from the load side of the power distribution system to the power source side. For example, a magnetic sensor can be used as a signal extractor used in the information transmission system according to the present invention. The principle of extraction using the magnetic sensor will be explained below. FIG. 3 shows the relative positional relationship between the neutral wire and the magnetic sensor. In the figure, 14 is a neutral wire, 15 is a coil, and 16 is a ferromagnetic material. In Figure 3, from the front to the back of the paper, the frequency f
CH2], and a current I (A) is flowing, the magnetic field H at a distance r (m) to the coil 15 is given by (2) according to the ampere circuit law. Therefore, from the magnetic flux density B=μH (wb/1rr), if the radius of the coil 15 is a Cm), the total number of magnetic fluxes Φ is: φ渭π・a” −B=π・a!・μH■ =π・a2 ・μ・□(wb)−・−・−・−(2)2
It becomes πr. Therefore, the voltage E induced in the coil 15 becomes 2 π f E=□·N·Φ, where N is the number of turns of the coil 15. When the coil 15 is wound around the ferromagnetic material 16, a phenomenon occurs in which magnetic flux is attracted to the ferromagnetic material 16, so that the induced voltage E in equation (3) becomes larger than in the case of an air-core coil. Therefore, when extracting the signal flowing through the neutral wire 14, if the commercial frequency fCHZ) and the signal frequency fo (Hz) are set, then the output voltages due to each magnetic field are E (V), E, C■]. (3) From the second point, the relationship f essentially holds, so the signal frequency f. By selecting an appropriate value for , a signal can be detected based on the induced voltage of the coil 15, and signal extraction becomes possible. Further, as shown in FIG. 3, if a capacitor 17 is added in parallel to the coil 15 to provide a parallel resonance condition, only the voltage of the necessary signal frequency can be extracted with emphasis. The resonance frequency f at this time is expressed by the following equation. FIG. 4 shows an embodiment for installing a coil in a magnetic field around a neutral wire, in which a support 18 having a portion hooked to the neutral wire 14 is made of an insulator, and this support A coil 15 and a ferromagnetic material 1G are embedded inside a body 18. With such a configuration, a signal can be extracted simply by hooking the support 18 at any point on the neutral wire. FIG. 5 is an explanatory diagram of another power distribution system configuration for implementing the information transmission system according to the present invention. In Figure 5, the first
The same components as in the figure are indicated by the same symbols, but the difference from the embodiment in Figure 1 is that a dedicated line 19 grounded on the power supply side is laid along the system, and is used for signal injection. The primary winding of the transformer 10 is connected between the voltage line 3 and the dedicated line 19, and the signal extractor 8 is attached to the dedicated line 19. The information transmission operation in such a configuration is the same as that shown in Fig. 1, and when the switch 11 is turned on and off at high speed, a high frequency current as shown in Fig. 2 flows through the dedicated line 19 from the load side to the power supply side. The high frequency current is detected by the signal extractor 8.

【Effect of the invention】

According to the present invention, the primary side of the signal injection transformer is connected in parallel between the voltage line and the neutral line or between the voltage line and the dedicated line,
Information is transmitted by turning a switch inserted on the secondary side on and off at high speed, making it possible to configure the transmission circuit with a transformer and a switch (transistor, etc.), making it easy to transmit information. The device can be made very simple and compact.

[Brief explanation of drawings]

Figures 1 and 5 are explanatory diagrams of the distribution line system configuration for implementing the information transmission method according to the present invention, Figure 2 is a waveform diagram of high frequency current used for information transmission, and Figure 3 is a magnetic diagram according to the present invention. FIG. 4 is a diagram showing the relative positional relationship between a sensor and a ground wire, and is a diagram showing an embodiment for installing a magnetic sensor in a magnetic field around a neutral wire. 1-11-1 high voltage distribution line, 2---- single pole transformer, 3
- voltage line, 4--neutral wire, 5--grounding wire, 6- solid device, 7- remote control slave station, 8--signal extractor, 9
, 13- Processing device, 10- Signal injection transformer,
11 --- Switch, 12 --- Phase detection section, 15
・-・Koi'f'] Figure-iz Figure

Claims (1)

[Claims] 1) In a system for transmitting information from the load side to the power supply side of a low-voltage distribution system, the primary side of a signal injection transformer is connected between the voltage line on the load side and the neutral line (ground phase). are connected in parallel, a switch is inserted in parallel on the secondary side, the switch is turned on and off at high speed in synchronization with the commercial frequency, a high frequency FS signal current is passed through the neutral wire, and this current change signal is An information transmission method characterized in that the information is received by a signal extractor provided on the power supply side. 2) For transmitting information from the load side of a low-voltage power distribution system to the power supply side, one dedicated line grounded on the power supply side is laid along the system, and a signal is injected between the load side distribution line and the dedicated line. The primary side of the transformer is connected in parallel, a switch is inserted in parallel on the secondary side, and the switch is turned on and off at high speed in synchronization with the commercial frequency to flow a high frequency FS signal current to the dedicated line. An information transmission method characterized in that this current change signal is received by a signal extractor provided on the power source side.