JPS6153840A - Distribution line carrier reception system - Google Patents

Abstract

PURPOSE:To acquire the arrival of a signal without any miss by constituting separately a circuit which detects a feeder through which a signal arrives and a circuit which receives it. CONSTITUTION:A scanning circuit 9 scans feeder current transformers 6a-6c successively at specific intervals, and when a signal arives at the scanning point of, for example, the current transformer 6a, the signal is inputted to a signal level decision circuit 15 through a BPF10a to detect the arrival of the signal, which is outputted to a control circuit 16. The circuit 16 commands a selecting circuit 17 to select and connect the current transformer 6a. Consequently, the signal arriving at the current transformer 6a is passed through a BPF10b and received by a synchronous detecting circuit 12, clock circuit 13, demodulating circuit 14, and data processing circuit 14. The circuit 16 outputs a disconnection command to the circuit 17 a specific time later to disconnect the current transformer 6a, and the circuit 9 scans the current transformers 6b and 6c at specific intervals. If a signal arrives at the current transformer 6b during the reception of the signal of the current transformer 6a, the circuit 16 stores that and commands a transmitting circuit 18 to resend data to the current transformer 6b after the signal of the current S transformer 6a is received and processed.

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 a plurality of feeders, from the load side to the power supply 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 the distribution line transmission/reception system in the radial direction. In the figure, fl) is the main distribution transformer, (2a
) to (2c) are feeder breakers, (3) are sectional switches, (4) are interconnection switches, (5) are high-voltage distribution lines, (6
a) to (6c) are feeder current transformers, (7) are distribution line carrier receiving devices (hereinafter referred to as receiving devices), (8a) to (8c)
) is a distribution line carrier transmitting device (hereinafter referred to as transmitting device).

In Figure 1, when the power distribution system is in a normal state, that is, there are no accidents or system changes, and all divisional switches (3) are closed and all interconnection switches (4) are open, ,
The carrier signals transmitted by the transmitting devices (8a) to (8c) upon receiving a polling signal transmitted by a carrier means such as a known multiple control method or automatically transmitted in a predetermined order are It is taken in and received by the receiving device (7) via predetermined feeder current transformers -a (6a) to (6c). That is, for example, the signal from the transmitter f (8a) is sent to the feeder current transformer (6a
) is received via.

However, when an accident occurs or construction work is carried out, the system is changed by operating a switch in order to disconnect the relevant power distribution section from the system, and the signal transmission route is also changed accordingly. For this reason, the transmitting device (8a) ~
(8C) and receiving feeder current transformers (6a) to (6c)
cannot be fixed uniquely, and therefore the receiving device (7)
As, any feeder current transformer (6a) to (6C)
It is required to have a configuration that can also receive signals arriving from.

Against this background, conventionally, power 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)
FnW is feeder detection word, SW is synchronization word, A
W is an address word and DW is a data word.

Now, in Fig. 2, (9) is the feeder current transformer (6a
) to (6c) cyclically, (lO) is a filter that removes noise components such as commercial frequencies and their harmonics and passes only signal frequency components, (1
1) is a demodulation circuit that demodulates the received signal, (12) is a synchronization detection circuit that detects the falling edge of the synchronization word SW of the signal, (1)
3) is a clock circuit that receives the output of the synchronization detection circuit θ and controls the demodulation timing; (I4) is a data processing circuit that is composed of a microprocessor and processes the data demodulated by the demodulation circuit (11); 05) is a signal level discrimination circuit that detects the arrival of a signal, and a control circuit that controls the scanning circuit (9).

Figure 4 shows that the scanning circuit (9) is connected to the feeder current transformer (6).
This is a time chart showing an example of the timing of cyclically switching a) to (6c). (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). T1 is the feeder detection word FDW in the signal
, I2 is the switching time during which the scanning circuit (9) sequentially switches the feeder current transformers (6a) to (6c), I3
is the length of one scanning cycle.

Next, the operation will be explained. Scanning circuit (9)
In the state where no signal has arrived, the feeder current transformers (6a) to (6c) are sequentially scanned at intervals of I2. For example, as shown in FIG.
When a signal arrives at the feeder current transformer (6a) at the time,
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 (
I5), the arrival of the signal is detected, and the scanning circuit (9) is locked to the feeder current transformer (6a) through the control circuit (country).Then, the signal passes through the filter (10). demodulation circuit (river and synchronization detection circuit (I2)
). In the synchronization detection circuit VJi (12), the falling timing of the synchronization word SW of the signal is detected, and a demodulation timing clock signal is input from the clock circuit 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 θ0 disappears, and the scanning circuit (9) switches to the next feeder current transformer ( From the selection of 6b), the normal scanning operation is resumed (at time t4), and preparations are made for the next reception.

Here, the relationship between the time length T1 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 T2, and the scanning cycle T3 is T1>I3 It is sufficient if the relationship -3×12 is established.

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

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by configuring the circuit for detecting the feeder from which the signal arrives and the circuit for receiving the signal separately,
When multiple signals arrive from multiple feeders at the same time, the signal from one feeder is normally received, and the other feeders receive the signal from the one feeder that received the signal. Detect only that
It is an object of the present invention to provide a distribution line transmission/reception system that can capture a transmitting device by, for example, later making a call to the transmitting devices connected to the feeder.

[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 reception μ: system applied to the distribution line carrier reception system according to the present invention, and the same parts as in FIG. In the same figure, (10a)
and (job) are filters that allow only signal frequency components to pass; 07) is a selection circuit that selects the feeder current transformers (6a) to (6c); and (18) is a transmitting unit using a tuple control method or the like.

FIG. 6 shows that the scanning circuit (9) and the selection circuit θη are connected to the feeder current transformer (6a)-(
6c) is a time chart showing an example of the timing for selecting 6c), in which (A) shows the signal that arrives at the feeder current transformer (6a), and (B) shows the signal that arrives at the feeder current transformer (6b). , the same figure (C) is a time chart when the scanning circuit (9) selects the feeder current transformer (6a), the same figure (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 a time chart for selecting the feeder current transformer (6a). T4 is the signal length, and T5 is the time during which the selection circuit selects and connects the feeder current transformer (6a) for reception.

Next, the operation will be explained. Scanning circuit (9)
The feeder current transformers (6a) to (6c) are sequentially scanned at intervals of T2 so as not to miss the arrival of a signal. For example, as shown in Figure 6,
When a signal arrives at the feeder current transformer (6a) at time tl, at the scanning time t2 of the feeder current transformer (6a), the signal that has passed through the filter (10) is input to the signal level discrimination circuit (16), Here, the arrival of the signal is detected and output to the control circuit (I6). Control circuit (le,)
receives this output signal and transfers the signal to the feeder current transformer (
6a), and instructs the selection circuit (17) to select and connect the feeder current transformer (6a) (at time t60). Then, the signal is received by the synchronization detection circuit (12), the clock circuit θ3), the demodulation circuit (11), and the data processing circuit (14) in the same manner as the conventional receiving circuit. The feeder current transformer (6
a), and when a predetermined time T5 has elapsed, a disconnection command is output from the control circuit (16) to the selection circuit (17J), and the feeder current transformer (6a) is disconnected (t
time point l).

On the other hand, the scanning circuit (9) includes the remaining feeder current transformers (6b) excluding the feeder current transformer (6a) that is receiving data.

For (6c), the scanning operation is continued in the cycle T3 and the arrival of a signal is waited for. Feeder current transformer (6
The scanning operation in a) is performed after the selection circuit (17) is released.
The process is restarted from time t4.

t5 while receiving the signal arriving at the feeder current transformer (6a)
The signal arriving at the feeder current transformer (6b) at the time t
At time B, the filter (10a) and signal level discrimination circuit θ
5), but the receiving circuit from the selection circuit 07) to the data processing circuit (14) is connected to the feeder current transformer (
The control circuit θ6 indicates that the incoming signal of 6a) is being received.
) makes a judgment and stores that the signal has also arrived from the feeder current transformer (6b). And feeder current transformer (6a)
At the time tl when the reception of the incoming signal from receive retransmissions from the transmitting device by means such as sending
Complete normal reception.

In addition, although the above example shows the case where the high voltage distribution line has 8 feeders, generally when the number of feeders is n,
As long as the relationship TI>T3=nXT2 is satisfied between the time length Tl of the feeder detection word FDW of the signal, the switching interval T2 of the scanning circuit (9), and the scanning cycle T3, the same operation as in the above embodiment can be performed. Due to the circuit configuration, among multiple signals that arrive time-wrapped from multiple transmitting devices scattered on a high-voltage distribution line via multiple feeders, one is normally received, and the other signals are received by the incoming feeder. can be captured, and therefore
The present invention can be applied to any power distribution system 1'l.

〔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 fail.

[Brief explanation of the drawings] Figure 1 is a conceptual diagram showing a distribution line carrier/receiver system that transmits signals from the load side of a high-voltage distribution line to the power source end, and Figure 2 is a conceptual diagram showing a distribution line carrier/receiver system applied to the conventional distribution line carrier/receiver system. FIG. 8 is a diagram showing the code structure of the distribution line carrier reception signal, FIG. 4 is a time chart showing an example of conventional reception operation, and FIG. 5 is the distribution line carrier reception according to the present invention. FIG. 6 is a block diagram showing an example of a receiver according to the present invention, and a time chart showing an example of a receiving operation according to the present invention. (1)...Main transformer for power distribution, (2a) to (2c)...
・Fiyada (A disconnector, (3)...Division switch, (4)...
Grid connection switch, (5)...High voltage distribution line, (6a) - (
6c)... Feeder current transformer, (7)... Distribution line carrier/receiver, (8a) to (8c)... Distribution line carrier/transmitter, (9)... Scanning circuit, (10) ... Filter, (11) ... Demodulation circuit, (I2) ... Synchronization detection circuit, (13) ... Clock circuit, (14) ...
data processing circuit, (+51... signal level discrimination circuit,
(16)...Control circuit, O''7)...Selection circuit, 0
→...Transmission section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In the distribution line carrier/receiver method 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 where the carrier signal arrives is automatically scanned. a means for detecting the
1. A distribution line transport receiving system, comprising means for receiving the detection signal, selecting a receiving feeder, and receiving the detection signal.