JP2001211571A - Distribution line carrier system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drop of carrier signal receiving level in a carrier circuit at a part of a disconnecting switch on a distribution line. SOLUTION: In a distribution line carrier system composed of coupling devices 7, 8 arranged in front and in the rear of the disconnecting switch 1 connected to distribution lines 2, 3 and the carrier circuit of a remote station 9 connected between the coupling devices 7, 8, the remote station 9 is provided with a pair of two-winding transformers 16, 17, each composed of a single primary winding and double secondary windings. The primary windings of the transformers 16, 17 are connected to the coupling devices 7, 8 respectively. The receiving part is composed of connecting the first secondary winding 16c of the transformer 16 with the first secondary winding 17c of the transformer 17. The transmitting part is composed of connecting the second secondary winding 16b of the transformer 16 with the second secondary winding 17b of the transformer 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring of a distribution line and a switch by superimposing and transmitting a carrier signal on a distribution line between a master station such as a substation and a slave station on a switch side. The present invention relates to a distribution line transport system that performs opening / closing control, state monitoring, and the like.

[0002]

2. Description of the Related Art In a distribution line transport system of this type, a switch is instructed to open and close based on a carrier signal received by the switch side, and the state of the switch is monitored. In this state, a dedicated coupler for transmitting and receiving only the carrier signal is used. FIG. 5 shows a switch control system in the distribution line transport system described in Japanese Patent Application Laid-Open No. H11-308786, in which the power supply side distribution line 12D and the control device 13 of the distribution line 12 to which the switch 11 is connected are connected. Is connected to the load side line 12F.
A load-side coupler 14 </ b> F is connected between the control device 13 and the control device 13.

Each coupler 14D, 14F is connected to each distribution line 12
This is for transmitting and receiving only the carrier signal between the D and 12F and the control device 13 in an insulated state. FIG.
4D and 14F, showing the distribution lines 12D and 1F.
It comprises a series circuit of a coupling capacitor (coupling capacitor) 141 having one end connected to 2F and a coupling filter 142 for extracting a carrier signal.

FIG. 7 is a single-line diagram schematically showing a distribution line conveying system partially including the configuration shown in FIG. 5, and the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals. . 7, reference numeral 20 denotes a master station provided at a substation on the power supply side, reference numeral 21 denotes a carrier circuit, and reference numeral 22 denotes a coupler of the master station. Switch 1
On one side, a slave station 30 for processing a carrier signal transmitted and received via the couplers 14D and 14F is provided. The slave station 30 includes a two-winding transformer (transformer with a tertiary winding), and one of the secondary windings forms a receiving unit of the carrier circuit, and the other forms a transmitting unit. The slave station 30 has a control device (13 in FIG. 5) for controlling the opening and closing of the switch 11, but is not shown in FIG.

In FIG. 7, when the switch 11 is open, for example, the carrier signal sent from the master station 20 is
Coupler 22, distribution line 12D, coupler 14 on slave station 30 side
The signal is transmitted to the closed circuit between D and 14F and to the receiver of the carrier circuit on the slave station 30 side. That is, if the carrier signal is described in order from the transmission side, a → b → c, d.

[0006]

However, FIG.
, The carrier signal a is converted to the carrier signal b with almost no attenuation.
Are split into a carrier signal c and a carrier signal d.
However, the carrier signal b is a signal superimposed as a high frequency signal synchronized with the commercial frequency power supply, and in a closed circuit between the couplers 14D and 14F on the slave station 30 side, the resonance resistors R1 and R2 and the load side Is attenuated to some extent by the coupler 14F, so that the carrier signal d partially branched also becomes small.

For this reason, the slave station 3 to which the carrier signal d is input
In the carrier circuit on the 0 side, for the signal input from the receiving unit, the commercial frequency component is cut by a filter, only the carrier signal is extracted, impedance matching is performed, amplification is performed, and the carrier signal component is divided into rectangular waves. When the digital signal is converted into a digital signal, there is a problem that sufficient reception cannot be performed because the original carrier signal d is small. SUMMARY OF THE INVENTION An object of the present invention is to provide a distribution line transport system that prevents a decrease in the reception level of a carrier signal.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a distribution line conveying system for controlling the opening and closing of a switch and monitoring the state of the switch, wherein the switch is connected to a distribution line. In the distribution line transport system, a coupler for insulating and transmitting and receiving carrier signals is arranged on the master station side and the slave station side and a carrier circuit on the slave station side is formed between the couplers. A pair of two-winding transformers comprising a primary winding and two secondary windings are provided in the carrier circuit, the primary windings of both transformers are respectively connected to the coupler, and one of the transformers is connected to the other. And the first secondary winding of the other transformer are connected to form a receiver, and the second secondary winding of one transformer and the first secondary winding of the other transformer are connected to each other. 2 is connected to the secondary winding to form a transmission unit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a wiring diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a switch, which is connected to a power distribution line 2 on the power supply side and a distribution line 3 on the load side. In the distribution line 2 on the power supply side, a master station 6 including a carrier circuit 4 and a coupler 5 is provided.
Is installed. The master station 6 is provided, for example, in a substation of a power company. Couplers 7 and 8 are connected to the distribution line 2 and the distribution line 3 near the switch 1. A slave station 9 having a carrier circuit is connected between the other end of the coupler 7 and the other end of the coupler 8. The configuration of the couplers 7 and 8 is the same as that of FIG. 6 and includes coupling capacitors 71 and 81 and coupling filters 72 and 82. In addition, parent station 6
The structure of the coupler 5 is the same as that of the couplers 7 and 8.

The slave station 9 includes two winding transformers (transformers with a tertiary winding) 16 and 17. Double winding transformers 16 and 17
Has one primary winding and two secondary windings,
The primary winding 16a of the two-winding transformer 16 is a coupling filter 72.
The primary winding 17 a of the two-winding transformer 17 is connected to the coupling filter 82. In addition, each 2
The secondary windings 16b and 16c of the present two-winding transformer 16 and the secondary windings 17b and 17c of the two-winding transformer 17 are connected to each other, one of which is a carrier circuit receiving unit, and the other is a carrier circuit. It is a transmission unit. These transmission / reception units are connected to a control device (not shown). Here, the secondary windings 16c, 1
7c is the first secondary winding in the claims, 16b, 17
b corresponds to the second secondary winding. In FIG. 1,
a, b, e, f, and g indicate carrier signals. As described above, according to the present invention, the resistances R1 and R2 at both ends of the slave station side carrier circuit, which are conventionally installed, are eliminated, and the pair of two-winding transformers 1
With the provision of 6 and 17, the carrier signal g received on the slave station 9 side is extracted only by electromagnetic coupling without branching the carrier signal e on the coupler 7 side, so that the reception voltage level is stabilized.

FIG. 2 is an equivalent circuit of the two-winding transformer 16 shown in FIG. 1. In FIG. 2, "-" corresponds to a terminal symbol of the two-winding transformer 16, and "," denotes a connection of the primary winding 16a. Terminal,
, Are connection terminals of the secondary winding 16b, and are connection terminals of the secondary winding 16c. In the figure, Z ₀ is the excitation impedance of the transformer 16, and Z ₁ is the primary winding 16 a of the transformer 16.
(Synthesis of winding resistance and the winding reactance) impedance, Z ₂ is (Synthesis of winding resistance and the winding reactance) one of the secondary winding 16b of the secondary winding of the transformer 16 impedance, Z ₃ is This is the impedance of the other secondary winding 16c (combination of winding resistance and winding reactance) of the secondary winding of the transformer 16.

FIG. 3 is an equivalent circuit obtained by simplifying FIG.
FIG. 4 shows a slave station of the conventional circuit of FIG. 7 shown for comparison.
30 is an equivalent circuit of a carrier circuit portion in FIG. In any circuit
Also Z ₀Is large enough and Z_TwoThis is assumed to be small enough
They are omitted. The combined impedance Z in FIG.
_LIs a composite of the load-side distribution line 3 and the coupler 8
In order to secure the reception level of the carrier circuit receiver,
Is preferably smaller, and in the present invention, the primary
The impedance viewed from the side is 0 to 75Ω. Figure
4, the combined impedance Z_LIs the load side distribution in FIG.
It is a composite of the electric line 12F and the coupler 14F.
You. Further, the combined impedance Z in FIG._KIs the result
The combiner 7, the power supply-side distribution line 2 and the combiner 5 are combined.
Is the total impedance of this system
75Ω. The combined impedance Z in FIG.
_KAre the coupler 14D7 of FIG.
And a combiner 22.

In FIGS. 3 and 4, 75Ω is the impedance of the controller on the master station side (electric power company substation side), and 10kΩ is the impedance of the controller on the slave station side. The turns ratio of the two-winding transformer in the embodiment was 3.06. Here, the windings 16a of the two-winding transformer,
Assuming that the impedance Z ₁ and Z ₃ of the 16c are 25Ω of the actual device and the power supply voltage is 100 V, the reception voltage levels of the present invention (the equivalent circuit of FIG. 3) and the conventional circuit (the equivalent circuit of FIG. 4) are as follows. Become like

[0014]

[Table 1]

As described above, in the case where the combined impedance Z _L of the load-side distribution line is 0Ω, the present invention can obtain a reception voltage higher than that of the conventional circuit, and when Z _L is 75Ω, a large reception voltage level can be obtained. Improvement can be achieved.

[0016]

As described above, according to the present invention, the carrier circuit of the slave station is provided with a pair of two-winding transformers, and is carried only by electromagnetic coupling without branching from the coupler via a resistor. Since signals are transmitted and received, the effect of improving the reception voltage level can be obtained.

[Brief description of the drawings]

FIG. 1 is a wiring diagram showing an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of a two-winding transformer part of FIG.

FIG. 3 is a simplified equivalent circuit diagram of FIG. 2;

FIG. 4 is an equivalent circuit diagram of a main part of a conventional circuit.

FIG. 5 is a diagram showing a conventional example.

FIG. 6 is a diagram showing a main part of FIG. 5;

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch 2,3 Distribution line 4 Carrier circuit 5 Coupler 6 Parent station 7,8 Coupler 71,81 Coupling capacitor 72,82 Coupling filter 9 Child station 16,17 Two-winding transformer 16a Primary winding 16b, 16c Secondary winding 17a Primary winding 17b, 17c Secondary winding

Claims (1)

[Claims] 1. A distribution line transport system for controlling the switching of a switch and monitoring its state, wherein the transmission signal is insulated and transmitted to and from a master station and a load side of a switch connected to a distribution line. Distribution system in which couplers are arranged for each other and a carrier circuit on the slave station side is formed between the couplers, wherein two primary windings each including one primary winding and two secondary windings are provided. A line transformer is provided in the carrier circuit, a pair of primary windings of both transformers are respectively connected to the coupler, and a first secondary winding of one transformer and a first winding of the other transformer are connected. The secondary winding is connected to form a receiving section, and the second secondary winding of one transformer is connected to the second secondary winding of the other transformer to form a transmitting section. Characteristic distribution line transport system.