JPS6328536B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distribution line transport system for transmitting signals from a load side to a power supply end (hereinafter referred to as an upstream direction) using a high voltage distribution line having a plurality of feeders.

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 upstream distribution line transportation system. In the figure, 1 is the main distribution transformer, 2
a to 2c are feeder switches, 3 is a division switch, 4 is a grid connection switch, 5 is a high voltage distribution line, 6a to
6c is a feeder current transformer, 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 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 the divisional switches 3 are in the closed state and all the interconnection switches 4 are in the open state, the transmitting devices 8a to 8c The carrier signals received and transmitted by a carrier means such as a well-known ripple control system, or transmitted automatically in a predetermined order, are sent to respective predetermined feeder current transformers 6a to 6a.
6c, and is taken in and received by the receiving device 7. That is, for example, a signal from the transmitting device 8a is received via the feeder current transformer 6a.

However, when an accident occurs or construction work is performed, a system change is performed to disconnect the power distribution section from the system, and the signal transmission route is also changed accordingly. For this reason, the transmitting device 8a
~8c and the feeder current transformers 6a to 6c that receive the feeder current transformers 6a to 6c cannot be fixed uniquely, so the receiving device 7 must have a configuration that can receive the incoming signal from any of the feeder current transformers 6a to 6c. is required.

Against this background, conventionally, distribution lines have been carried using a receiver having a circuit configuration as shown in FIG. 2 and a carrier signal having a general code configuration as shown in FIG. In Figure 3, CW is the synchronization word,
AW is the address word and DW is the data word.

In FIG. 2, 9a to 9c are filters that remove noise components such as commercial frequencies and their harmonics and pass only signal frequency components, 10a to 10c are demodulation circuits that demodulate received signals, and 11a to 11c are signal synchronization circuits. Synchronous detection circuits 12a to 12c detect the falling edge of word CW; 12a to 12c are synchronization detection circuits 11a to 1;
A clock circuit 13 receives the respective outputs of the demodulation circuits 1c and controls the demodulation timing, and a data processing circuit 13 includes a microprocessor or the like and processes the data demodulated by the demodulation circuits 10a to 10c.

Next, the operation will be explained.

Optional feeder current transformer 6a, 6b or 6c
The signal arriving from the receiver is received by the independent receiving circuit. For example, transmitting from the transmitting device 8a,
The signal taken in from the feeder current transformer 6a passes through a filter 9a and is input to a demodulation circuit 10a and a synchronization detection circuit 11a. The synchronization detection circuit 11a detects the falling timing of the synchronization word CW of the signal and outputs the signal from the clock circuit 12a to the demodulation circuit 10.
A demodulation timing clock signal is input to a. The address and data of the transmitter 8a demodulated by the demodulation circuit 10a are subjected to predetermined processing in the data processing circuit 13, and reception is completed.

Since the conventional receiving device is configured as described above, the number of receiving circuits is required according to the number of feeders on the high-voltage distribution line, and in particular, the filters 9a to 9c are required to extract minute signals from high noise. Therefore, the circuit had drawbacks such as being extremely complex and expensive.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is a distribution line transport system that changes the signal code configuration and can be applied even when there are a large number of feeders with a simple receiving circuit configuration. is intended to provide.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, 14 is a feeder current transformer 6a~
6c is a scanning circuit that selects a signal; 15 is a signal level determination circuit that detects the arrival of a signal;
6 is a control circuit that controls the scanning circuit 14.

FIG. 5 shows the code structure of the signal, in which a feeder detection word FDW is added to the conventional code (FIG. 3).

FIG. 6 is a time chart showing the timing at which the scanning circuit 14 selects the feeder current transformers 6a to 6c. FIG. 6A shows the signal arriving at the feeder current transformer 6a, and FIG. Time chart to select, C in the same figure is feeder current transformer 6
D is a time chart for selecting the feeder current transformer 6c.
_T1 is the time length of the feeder detection word FDW in the signal, _T2 is the switching time during which the scanning circuit 14 sequentially switches 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 14 sequentially scans the feeder current transformers 6a to 6c at intervals of _T2 when no signal is received. 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 9a is sent to the signal level discrimination circuit 15. The arrival of the signal is detected, and the scanning circuit 14 is locked to the feeder current transformer 6a via the control circuit 16. Then, the signal is normally received by the synchronization detection circuit 11a, the clock circuit 12a, the demodulation circuit 10a and the data processing circuit 13, similar to the conventional receiving circuit.

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 14 selects the next feeder current transformer 6b according to a command from the control circuit 16. The device returns to normal scanning operation (at time _t4 ) and prepares to receive the next signal.

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 will be explained. Since the number of feeders in the high-voltage distribution line, that is, the number of feeder current transformers, is three, there is a relationship of T ₃ = 3 × T ₂ , and the feeder current transformers 6a to 6a to which the signal arrives
In order to normally detect 6c, T ₁ should be set so that the relationship T ₁ > T ₃ holds true.

Although the above example shows the case where the high-voltage distribution line has three feeders, in general, when the number of feeders is n, the signal feeder detection is performed so that T ₁ > T ₃ = n × T ₂ . It is only necessary to set the time length T ₁ of the word FDW, and therefore, the present invention can be applied to any power distribution system.

As described above, according to the present invention, the receiving feeder selection code is added to the carrier signal and the receiving feeder is selected using the scanning method, thereby making the circuit configuration of the receiving device extremely simple and inexpensive. It has the effect of getting something.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing a distribution line carrier system for transmitting signals from the load side of a high-voltage distribution line to the power source end, Figure 2 is a circuit configuration diagram showing a conventional distribution line carrier/receiver device, and Figure 3
The figure shows the code structure of a conventional distribution line carrier signal.
FIG. 4 is a circuit configuration diagram showing an embodiment of the distribution line carrier type receiving device according to the present invention, FIG. 5 is a diagram showing the code structure of the distribution line carrier signal of the present invention, and FIG. This is a time chart showing an example of operation. 1...Distribution transformer, 2a-2c...Feeder switch, 3...Division switch, 4...Grid connection switch, 5
...High voltage distribution line, 6a-6c...Feeder current transformer, 7
...Distribution line carrier receiving device, 8a-8c...Distribution line carrier transmitting device, 9a-9c...Filter, 10a-1
0c...Demodulation circuit, 11a-11c...Synchronization detection circuit, 12a-12c...Clock circuit, 13...Data processing circuit, 14...Scanning circuit, 15...Signal level discrimination circuit, 16...Control circuit, FDW...Feeder detection word. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a distribution line transport method in which a current signal is transmitted from the load side to the power supply end using a metal circuit of a high-voltage power distribution line having multiple feeders as a transmission path, a signal necessary for detecting the receiving feeder is added to the carrier signal, and the A distribution line conveyance system that uses a scanning method to automatically detect the incoming feeder from among multiple feeders.