JP2001160769A - Current transportation transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize circuit constitution smaller and more inexpensive than a conventional one for connecting a phase detection means between direct power lines. SOLUTION: In a current transportation transmitter forming a current transportation signal and injecting it to the power line in synchronizing with the phase of the power wave of the power line, which is detected by a phase detection means 5 connected between the power lines 1, a half wave rectification diode 2 which half wave-rectifies the power wave of the power line and a switching element 4 forming the current transportation signal by interrupting current which is half wave-rectified on the cathode side of the half wave rectification diode are connected in series between the power lines. The ground circuit 9 of the phase detection means and one end connected to the power line of the switching element are connected to same potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a current carrier transmitter for transmitting a carrier signal such as an audible frequency in the form of a current signal using a power line such as a distribution line.

[0002]

2. Description of the Related Art The following is a conventional technique. There is a current carrier system in which an audible frequency current carrier signal is transmitted from a load side to a power supply terminal using a distribution line as a transmission line. In this case, a transmitter generated by a signal generator 57 is used as shown in FIG. The sine wave current having the audible frequency is amplified by an amplifier 56 and injected into the low-voltage distribution line 51 through a coupling circuit 52 including capacitors 53 and 54 and a transformer 55. 58 is a phase detection circuit for synchronizing the modulated signal generated by the signal generator 57 with the phase of the commercial frequency of the distribution line 51. As shown in FIG. 6, the prior art includes a full-wave rectifier 62 and a transistor 64 which is turned on / off by a pulse having a signal frequency generated by a signal generator 66 and intermits a current flowing through a resistor 63. A method of injecting a signal current into the low-voltage distribution line 61 by using a chopper circuit formed from the following has been proposed. The prior art does not include the pulse transformer 65 and the phase detection circuit 67 shown in FIG.

[0003]

In the case of converting the current signal into a signal synchronized with the phase of the commercial frequency in the above-mentioned prior art method, there is a transformer 55 as shown in FIG. And the phase detection circuit 58 can be directly connected to the distribution line 51, but has the disadvantage that the coupling circuit 52 is expensive and large in size.

As described above, the prior art system does not include the pulse transformer 65 and the phase detection circuit 67 shown in FIG. 6, so that the transmission of the carrier signal synchronized with the phase of the commercial frequency of the distribution line 61 is performed. Is not considered at all. In order to realize the transmission of a carrier signal synchronized with the phase of the commercial frequency of the distribution line 61 by the conventional technique, as shown in FIG. It is necessary to add a circuit for ensuring electrical insulation on the output side of the rectifier 62. The reason is that, if not insulated by the pulse transformer 65 or the like, one end on the input side of the full-wave rectifier 62 is grounded by the earth circuit of the phase detection circuit 67, and one end on the output side of the full-wave rectifier 62 is connected to the signal generator. This is because both the ends of one rectifier of the full-wave rectifier 62 are short-circuited by the ground circuit, and the full-wave rectifier 62 does not perform the rectifying action. As described above, the conventional technique requires an insulating circuit such as the pulse transformer 65, and thus has a disadvantage that the circuit configuration is complicated and expensive.

(Object of the Invention) An object of the present invention is to provide a current carrier transmitter capable of realizing a circuit configuration smaller and less expensive than the conventional one when connecting the phase detecting means directly between power lines. It is to provide.

[0006]

In order to achieve the above object, the present invention provides a method for controlling a current carrier signal in synchronism with the phase of a power line power wave detected by phase detecting means connected between the power lines. In a current carrier transmitter for injecting into a power line, a half-wave rectifying diode for half-wave rectifying a power wave of the power line, and intermittently half-wave rectified current on the cathode side of the half-wave rectifying diode. The switching element forming the current carrier signal is connected in series between the power lines, and the ground circuit of the phase detection means and one end of the switching element connected to the power line are connected to the same potential. It is characterized by the following.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A basic circuit diagram of an embodiment of the present invention is as shown in FIG. That is, the half-wave rectifier diode 2, the resistor 3, and the transistor 4 are connected in series between distribution lines (power lines), and the commercial frequency (power wave)
Is also connected between the lines of the distribution line 1. The anode of the half-wave rectifier diode 2 is connected to one side of the distribution line 1, the collector of the NPN transistor 4 is connected to the cathode of the half-wave rectifier diode 2 via the resistor 3, and the emitter of the transistor 4 is connected to the distribution line. 1 to the other. A signal generator 6 is connected to the base of the transistor 4, and the signal generator 6
A modulated signal is generated in synchronization with the phase of the commercial frequency of the distribution line 1 detected by the phase detection circuit 5, and the modulated signal causes the transistor 4 to flow through the resistor 3 on the cathode side of the half-wave rectifying diode 2. Is turned on and off to form a current carrier signal, which is injected into the distribution line 1 (superimposed on the commercial frequency of the distribution line 1). The half-wave rectifying diode 2, the resistor 3, and the transistor 4 constitute a transmitting unit 7 of the current carrier transmitter. The transistor 4 constituting the switching element of the present invention includes:
However, the present invention is not limited to this.
A switching element such as O may be used instead. The emitter of the transistor 4 is commonly connected to the ground circuit 8 of the signal generator 6.

The earth circuit 9 of the phase detection circuit 5 and the emitter (earth circuit 8) of the transistor 4 connected to the other side of the distribution line 1 are connected to the same potential (ground potential).

Since the half-wave rectifier diode 2 is not connected to the ground circuit side, an insulating circuit such as a pulse transformer shown in FIG. 6 is not required, and the phase detection circuit 5 can be directly connected to the distribution line 1. . As a result, the phase detection circuit 5 and the transmitter 7 can be matched in the ground circuit, and the current carrier signal can be transmitted in synchronization with the phase of the commercial frequency.

[0010] The current carrier transmitter is installed at each floor outlet of a customer or a building. When installed at the customer, the signal is modulated by management information such as voltage and current of the distribution line, meter reading data of the watt hour meter, etc., and superimposed on the commercial frequency of the distribution line in the form of a current carrier signal. The signal is transmitted to the repeater on the secondary side of the upper transformer, and further transmitted from the repeater to the central unit of the substation. When installed on each floor outlet of a building, the signal is modulated by temperature, humidity, contact information, etc., superimposed on the commercial frequency of the distribution line in the building in the form of a current carrying signal, and the power supply transformer in the electric room To the centralized monitoring device on the secondary side.

FIG. 2 shows a specific circuit according to an embodiment of the present invention. The arithmetic processing unit 10 receives the phase detection signal from the phase detection circuit 5, outputs a modulated signal to the base of the transistor 4, and includes the function of the signal generator 6 in FIG. Arithmetic processing unit 10, memory 1
1 and the ground circuit of the interface circuit 12 are commonly connected to a ground terminal 14 of a power supply unit 13 for driving the circuit. The power supply unit 13 is connected to the distribution line 1 via a voltage transformer 16. Further, a drive voltage is supplied from a power supply terminal 15 of the power supply unit 13 to each required circuit unit. In the phase detection circuit 5, the line voltage of the distribution line 1 is divided by the resistors 17 and 18 and added to the base of the transistor 19. This transistor 19 inverts the on / off state at the zero phase of the line voltage of the distribution line 1. Then, a pulse signal (phase detection signal) is transmitted. The arithmetic processing unit 10 constantly monitors the pulse signal input from the phase detection circuit 5 and
By supplying a modulated signal required for generating a carrier signal to the transmission unit 7 to the transmission unit 7 at a time interval determined at a timing synchronized with the phase of the commercial frequency to the transistor 4 in accordance with the command from the This is to perform comprehensive control for injecting. The unique ID data, frequency data, timing data, and the like necessary for this series of process operations are stored in the memory 11 connected to the arithmetic processing unit 10, and are read and written as needed.

The transmission timing synchronized with the phase of the commercial frequency of the distribution line 1 is as shown in FIG.
A schematic equivalent circuit of the operation function of 0 is as shown in FIG. When the phase detection signal b synchronized with the commercial frequency a is input from the phase detection circuit 5, it is inverted by the inverter 20, and the logical product of the phase detection signal b 'inverted by the AND gate 21 and the carrier clock c is taken. The unmodulated signal d
Is generated, and the unmodulated signal d is modulated by the transmission data e by the AND gate 22, and the modulated signal f (switching control signal) is supplied to the base of the transistor 4 to switch the transistor 4. As a result, a current carrying signal g is formed and injected into the distribution line 1.

According to the embodiment of the present invention described above, the following advantages are obtained.・ By using a method of connecting the earth circuit of the phase detecting means of the commercial frequency and one end of the switching element connected to the distribution line to the same potential, a coupling circuit required in the prior art,
The need for a pulse transformer or the like is eliminated, and the number of circuits and components is smaller than that of a conventional one, resulting in a small current carrying transmitter.・ Product price is lower than conventional products.

[0014]

As described above, according to the present invention,
As in the prior art, coupling circuits and additional circuits required for insulation are not required, and the phase detection means can be directly connected to the power line.Therefore, there is no phase delay, and the phase angle of the commercial frequency can be reliably detected and accurate. A current carrier signal synchronized with the phase can be transmitted, and a circuit configuration smaller and less expensive than the conventional one can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific circuit of one embodiment of the present invention.

FIG. 3 is a diagram illustrating a transmission timing of the current carrier transmitter of FIG. 2;

FIG. 4 is a diagram showing a schematic equivalent circuit of an arithmetic function of an arithmetic processing unit in FIG. 2;

FIG. 5 is a diagram showing an example of a conventional technique.

FIG. 6 is a diagram showing a circuit configuration based on another example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Distribution line 2 Diode for half-wave rectification 3 Resistance 4 Transistor 5 Phase detection circuit 6 Signal generator 7 Transmission part 8 Earth circuit 9 Earth circuit 10 Arithmetic processing part 11 Memory 12 Interface circuit 13 Power supply part 14 Earth terminal 15 Power supply terminal 16 Voltage Transformer 17 Resistance 18 Resistance 19 Transistor 20 Inverter 21 AND gate 22 AND gate

Claims (1)

[Claims] 1. A current carrier transmitter which forms a current carrier signal in synchronization with a phase of a power wave of a power line detected by a phase detecting means connected between the power lines and injects the power line into a power line. A half-wave rectifier diode for half-wave rectification of the power wave, and a switching element for forming the current carrier signal by interrupting the half-wave rectified current on the cathode side of the half-wave rectifier diode; A current carrier transmitter which is connected in series between lines, and wherein an earth circuit of the phase detecting means and one end of the switching element connected to a power line are connected to the same potential.