JPS6360575B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention utilizes a distribution line transmission/reception system, specifically, a high-voltage distribution line having multiple feeders, from the load side to the power source end (hereinafter referred to as the upstream direction). ) This relates to the receiving method of the transmitted signal.

[Prior art]

Generally, when transmitting a signal in the upward direction using a metal circuit of a high-voltage power distribution line, a current signal is used as a carrier signal because the power supply end has the lowest impedance.

FIG. 1 shows a conceptual diagram of an upstream distribution line carrier reception system. In the figure, 1 is a main distribution transformer, 2a to 2c are feeder switches, 3 is a division switch, 4 is a interconnection switch, 5 is a high-voltage distribution line, and 6
Numerals a to 6c are feeder current transformers, 7 is a distribution line carrier receiving device (hereinafter referred to as a receiving device), and 8a to 8c are distribution line carrier transmitting devices (hereinafter referred to as a transmitting device).

In FIG. 1, when the power distribution system is in a normal state, that is, there is no accident or system change, and all divisional switches 3 are closed and all interconnection switches 4 are open, transmitting devices 8a to 8c receives and transmits a polling signal transmitted by a known ripple control type carrier means, or transmits a carrier signal automatically in a predetermined order, respectively, to a predetermined feeder current transformer 6a.
~6c, and is taken into the receiving device 7 and received. That is, for example, a signal from the transmitting device 8a is received via the feeder current transformer 6a.

However, in the event of an accident or construction work being carried out, the system will be changed by operating a switch in order to disconnect the relevant distribution section from the system.
Along with this, the signal transmission path is also changed. For this reason, the transmitting devices 8a to 8c and the receiving feeder current transformers 6a to 6c cannot be fixed uniquely, and therefore the receiving device 7 cannot accept the incoming signals from any of the feeder current transformers 6a to 6c. It is required that the configuration is capable of receiving.

In the background described above, conventionally, distribution line transmission has been carried out using a receiver having a circuit configuration as shown in FIG. 2 and a carrier signal having a code configuration as shown in FIG. In Figure 3, FDW is the feeder detection word, SW is the synchronization word, AW is the address word,
DW is a data word.

Now, in Fig. 2, 9 is the feeder current transformer 6.
10 is a filter that removes noise components such as commercial frequencies and their harmonics and passes only signal frequency components; 11 is a demodulation circuit that demodulates the received signal; 12
1 is a synchronization detection circuit that detects the fall of the synchronization word SW of the signal; 13 is a clock circuit that receives the output of the synchronization detection circuit 12 and controls the timing of demodulation;
4 is a data processing circuit that is composed of a microprocessor or the like and processes the data demodulated by the demodulation circuit 11; 15 is a signal level discrimination circuit that detects the arrival of a signal; 16 is a control circuit that controls the scanning circuit 9; It is.

FIG. 4 is a time chart showing an example of the timing at which the scanning circuit 9 cyclically switches the feeder current transformers 6a to 6c. FIG. 4A shows the signal arriving at the feeder current transformer 6a, and FIG. Time chart for selecting device 6a, same figure C
is a time chart for selecting the feeder current transformer 6b, and D is a time chart for selecting the feeder current transformer 6c. T ₁ is the time length of the feeder detection word FDW in the signal, T ₂ is the scanning circuit 9
is the switching time for sequentially switching the feeder current transformers 6a to 6c, and _T3 is the length of one cycle of scanning.

Next, the operation will be explained. The scanning circuit 9 sequentially scans the feeder current transformers 6a to 6c at intervals of _T2 when no signal is received. For example, as shown in FIG. 4, when a signal arrives at the feeder current transformer 6a at time _t1 , at the scanning time _t2 of the feeder current transformer 6a, the signal that has passed through the filter 10 is sent to the signal level discrimination circuit 15. The arrival of the signal is detected, and the scanning circuit 9 is locked to the feeder current transformer 6a via the control circuit 16.
Then, the signal passes through the filter 10 and is input to the demodulation circuit 11 and the synchronization detection circuit 12. The synchronization detection circuit 12 detects the fall timing of the synchronization word SW of the signal, and a demodulation timing clock signal is input from the clock circuit 13 to the demodulation circuit 11. The address and data demodulated by the demodulation circuit 11 are subjected to predetermined processing in the data processing circuit 14, and reception is completed.

When the reception of the signal is completed, that is, when the arrival of the signal ends (at time _t3 ), the output from the signal level discrimination circuit 15 disappears, and the scanning circuit 9 selects the next feeder current transformer 6b according to a command from the control circuit 16. Returns to normal scanning operation (at time t ₄ ) and prepares for the next reception.

Here, the relationship between the time length T ₁ of the feeder detection word FDW of the signal necessary for normal selection of the receiving feeder current transformers 6a to 6b, the switching interval T ₂ and the scanning cycle T ₃ is T ₁ > _T3 =3×
It suffices if the relationship T ₂ holds true.

Since the conventional receiving device is configured as described above, if the carrier signals are sequentially transmitted from each of the transmitting devices 8a to 8c so as not to overlap, they can all be received. In some cases, signals are simultaneously transmitted from multiple transmitting devices 8a to 8c via multiple feeders, and in this case, by scanning the feeder, only the signal of the first captured feeder is received, and the signals of other feeders are transmitted simultaneously. signals will be ignored.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by configuring a circuit for detecting the feeder from which the signal arrives and a circuit for receiving the signal separately, it is possible to simultaneously receive multiple signals from multiple feeders. When a signal arrives, one feeder receives the signal normally, and the other feeders that receive the signal only detect the arrival of the signal and, for example, later call all the transmitting devices connected to that feeder. It is an object of the present invention to provide a distribution line transmission/reception system that can capture a transmitting device by such means as performing the following steps.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 5 shows an example of a receiving device applied to the distribution line carrier receiving system according to the present invention, and the same parts as those in FIG. In the figure, 10a and 10b are filters that pass only signal frequency components, and 17 is a feeder current transformer 6a.
.about.6c, and 18 is a transmitter using a ripple control method or the like.

Figure 6 shows scanning circuit 9 and selection circuit 1.
7 is the feeder current transformer 6 in relation to the incoming signal.
This is a time chart showing an example of the timing for selecting a to 6c, in which A shows the signal arriving at the feeder current transformer 6a, B shows the signal arriving at the feeder current transformer 6b, and C shows the scanning circuit. 9 is a time chart for selecting the feeder current transformer 6a, D is a time chart for selecting the feeder current transformer 6b, E is a time chart for selecting the feeder current transformer 6c, and F is a time chart for selecting the feeder current transformer 6c. is the selection circuit 17
is a time chart for selecting the feeder current transformer 6a. T ₄ is the signal length, and T ₅ is the time during which the selection circuit 17 selects and connects the feeder current transformer 6a for reception.

Next, the operation will be explained. The scanning circuit 9 is connected to T ₂ so as not to miss the arrival of the signal.
The feeder current transformers 6a to 6c are sequentially scanned at intervals of . For example, as shown in FIG. 6, when a signal arrives at the feeder current transformer 6a at time _t1 , at the scanning time _t2 of the feeder current transformer 6a, the signal that has passed through the filter 10 is sent to the signal level discrimination circuit. The signal is input to the control circuit 15, where the arrival of the signal is detected and output to the control circuit 16. The control circuit 16 receives this output signal and determines that the signal is coming from the feeder current transformer 6a,
A command is given to the selection circuit 17 to select and connect the feeder current transformer 6a (at time _t6 ). Then,
The signal is sent to the synchronization detection circuit 1 as in the conventional receiving circuit.
2. Normally received by the clock circuit 13, demodulation circuit 11 and data processing circuit 14. connected to the feeder current transformer 6a by the selection circuit 17;
When the predetermined time _T5 has elapsed, a disconnection command is output from the control circuit 16 to the selection circuit 17, and the feeder current transformer 6a is disconnected (at time _t7 ).

On the other hand, the scanning circuit 9 is connected to the remaining feeder current transformers 6b, excluding the feeder current transformer 6a that is receiving data.
The scanning operation is continued in the cycle T3 for _6c , and the arrival of a signal is waited for. The scanning operation of the feeder current transformer 6a is resumed from time _t4 after the selection circuit 17 is released.

While receiving the signal arriving at the feeder current transformer 6a
The signal that arrives at the feeder current transformer 6b at time _t5 is detected via the filter 10a and the signal level discrimination circuit 15 at time _t8 , but the signal that arrives at the feeder current transformer 6b at time t8 is detected by the receiving circuits from the selection circuit 17 to the data processing circuit 14. is receiving the incoming signal of the feeder current transformer 6a.
The control circuit 16 makes a judgment and stores that the signal has also arrived from the feeder current transformer 6b. Then, the reception of the incoming signal from the feeder current transformer 6a is completed.
At time _t7 , the control circuit 16 instructs the transmitter 18 to stop the retransmission from the transmitter by sending a retransmission command signal to the transmitter group connected to the feeder current transformer 6b. Receive the transmission and complete normal reception.

Although the above embodiment shows the case where the high voltage distribution line has three feeders, generally when the number of feeders is n, the feeder detection word FDW of the signal is
time length T ₁ and switching interval T ₂ of the scanning circuit 9
and during scanning cycle T ₃ T ₁ > T ₃ =
As long as the relationship n x T ₂ is satisfied, even if the circuit configuration is the same as that of the above embodiment, multiple transmitters that arrive from multiple transmitters scattered on the high-voltage distribution line via multiple feeders and that are wrapped in time can be used. One of the signals is normally received, and the other signals can be captured by the incoming feeder. Therefore, the present invention can be applied to any power distribution system.

〔Effect of the invention〕

As described above, according to the present invention, since the structure has both a circuit for detecting the feeder where the signal arrives and a circuit for receiving the signal, it is possible to capture the arrival of the signal without exception.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing the distribution line carrier/receiver system that transmits signals from the load side of the high-voltage distribution line to the power supply side.
The figure is a block configuration diagram showing a receiving device applied to a conventional distribution line carrier reception system, Figure 3 is a diagram showing the code structure of a distribution line carrier reception signal, and Figure 4 is a timing diagram showing an example of a conventional reception operation. FIG. 5 is a block diagram showing an example of a receiving apparatus using a distribution line carrier receiving system according to the present invention, and FIG. 6 is a time chart showing an example of the receiving operation of the present invention. 1... Distribution main transformer, 2a to 2c... Feeder switch, 3... Division switch, 4... Grid connection switch, 5... High voltage distribution line, 6a to 6c... Feeder Current transformer, 7... Distribution line carrier/receiver, 8a~
8c... Distribution line carrier transmitter, 9... Scanning circuit, 10... Filter, 11... Demodulation circuit,
12...Synchronization detection circuit, 13...Clock circuit,
14...Data processing circuit, 15...Signal level discrimination circuit, 16...Control circuit, 17...Selection circuit,
18... Transmission section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a distribution line carrier/receiver system that transmits current signals from the load side to the power source end using the metal circuit of a high-voltage distribution line with multiple feeders as a transmission path, the feeder at which the carrier signal arrives is automatically detected using a scanning method. 1. A distribution line carrier reception system, comprising means for receiving the detection signal, selecting a receiving feeder, and receiving the detection signal.