JP2004080322A - Remote supervisory control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speed up transmission processing of supervisory control information between a master station and many slave stations. <P>SOLUTION: Relay stations 15<SB>1</SB>to 15<SB>5</SB>each having a communication function equivalent to that of the master station 11 are placed among the master station and the slave stations 12<SB>1</SB>to 14<SB>5</SB>in order to make communication through communication paths adopting a multi-drop method among the master station and the N slave stations and transmit information of a slave station having 'information to be transmitted' to the master station, each relay station adjusts the number of slave stations being relay objects to be a proper number, each relay station collects information of each slave station being the relay object temporally in parallel. Each relay station sequentially transmits the collected slave station information to the master station, collects / edits the information of the slave stations and has a changeover switch for transmission lines in its inside. By changing over the switch, communication is enabled among the master station and each of the slave stations not through the relay stations, and the switch selects the direct communication system among the master station and the slave stations or the communication system between the master station and the slave station through the relay station. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a remote monitoring and control system, and more particularly to a 1: N monitoring and control system in which a plurality of slave stations are connected in a multidrop manner to one communication line extending from a master station. The present invention relates to a transmission processing method of monitoring control information between stations.
[0002]
[Prior art]
As shown in FIG. 3, the remote monitor control system a plurality of slave stations 2 ₁ to 2 _N in one communication path extending from the master station 1 is connected in a multi-drop, and a plurality of slave stations simultaneously master station Since communication is not possible, it is necessary to appropriately control the order of communication between the master station and the slave stations, and the following transmission processing method is used.
[0003]
(1) Simple polling process All the slave stations connected to the communication line are sequentially called from one master station to perform communication. In this case, as shown in FIG. 4, in order to collect information from all the slave stations, if the communication time required for one slave station is t and the number of slave stations connected to the communication line is N, the longest is possible. Requires a time of t × N.
[0004]
(2) Divide the slave stations into several groups and divide the slave stations (n units) on the polling communication line into groups of a fixed number (m: m <n) or less. From the master station, communication is promoted to slave stations belonging to a certain group, and only slave stations having information to be transmitted (such as failure detection) return a response (for example, Japanese Patent Application Laid-Open No. 10-150493).
[0005]
In this method, the presence / absence of “information to be transmitted” can be determined for each group. Therefore, only when there is “information to be transmitted”, polling processing is sequentially performed for slave stations in the group in order. To collect information. In this case, as shown in FIG. 5, when there are 5 slave stations in one group and 5 groups in total (= 25 stations), if the communication time required for one slave station and 1 group is t, there is a certain case. The time required to collect the fault information detected by one slave station is at most t × 5 (group) + t × 5 (slave station of one groove) = 10t, and the simple polling described above takes the longest. The time can be reduced as compared with the case where 25t is required.
[0006]
[Problems to be solved by the invention]
(1) Problems of Simple Polling Processing The time required for communication increases in proportion to the number of slave stations (n).
[0007]
(2) Problems in the case of dividing a slave station into several groups and performing polling communication A case where there are a plurality of slave stations having information to be transmitted at the same time and they exist without bias in a specific group. Assuming that all the slave stations in each group are to be polled, it may take as long as or longer than the simple polling method of (1).
[0008]
For example, when the monitoring target is a distribution line switch in a distribution automation system, the opening / closing operation by the automatic recovery sequence in the event of a distribution line accident may not be able to detect a change in the state of the switch due to a long polling cycle. This will be described with reference to FIG.
[0009]
In FIG. 6, in a distribution system in which a distribution line is laid from a circuit breaker (CB) of a substation via a section switch, a master station is installed on the substation side, and a slave station is installed at each section switch location. Is provided with a monitoring system for transmitting the "on / off" information to the master station.
[0010]
In this system configuration, the power distribution automation system secures energization to a healthy section by a reclosing method when an accident occurs. In this case, the circuit breaker and the switch are normally set to “ON” and the power is distributed as shown in FIG. When the circuit breaker is automatically operated to “turn off” due to the occurrence of the distribution line accident shown in (b), the switch is released without voltage and the entire section is blacked out. Thereafter, at the start of reclosing shown in (c), the circuit breaker is first turned on and charged to the first segmented switch position. In this state, information indicating that there is a voltage upstream of the switch is transmitted to the master station. If no power failure occurs even after the elapse of x time period (about 10 seconds), each switch is automatically turned on as shown in (d).
[0011]
In contrast to the operations (a) to (d) according to the above automatic sequence, since each slave station has "information to be transmitted" called "switch-off state", all slave stations are subject to polling. As a result, the polling cycle becomes longer, and the master station cannot collect the "off" states of the switches (b) and (c) on the way.
[0012]
SUMMARY OF THE INVENTION An object of the present invention is to provide a remote monitoring control system capable of speeding up transmission processing of monitoring control information between a master station and a number of slave stations.
[0013]
[Means for Solving the Problems]
The present invention for solving the above problems has the following features.
[0014]
(1) In a remote monitoring control system for communicating between a master station and N slave stations via a multi-drop communication channel and transmitting information of the slave station having "information to be transmitted" to the master station,
A relay station having a communication function equivalent to the master station is arranged between the master station and the slave station,
Adjust the number of slave stations to be relayed by each relay station to an appropriate number,
Each relay station collects information on each slave station to be relayed in parallel in time,
The slave station sequentially transmits the slave station information collected by each relay station to the master station.
[0015]
(2) The relay stations are characterized in that the information of the slave stations to be relayed is summarized and edited to reduce the number of bits of the information and transmit the information to the master station.
[0016]
(3) The relay station is provided with a transmission path changeover switch therein, and by switching this switch, communication is enabled between the master station and each slave station without passing through the relay station.
[0017]
(4) The switching of the switch is performed by switching between a direct communication method between the master station and the slave station and a communication method between the master station and the relay station through the slave station and the relay station depending on the content of the communication. .
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a configuration diagram of a remote monitoring control system showing an embodiment of the present invention, and has the following configuration.
[0019]
(1) the master station 11 and the N base of the child station ₁₂ 1 _{to 12 5, 131-134 5,} 14 providing a plurality of relay stations ₁₅ 0 to 15 _m between 1-14 _5.
[0020]
(2) the relay station ₁₅ 1 to 15 _m makes it can communicate with the slave station ₁₂ 1 _{to 12 5, 131-134 5,} 14 1-14 ₅ plurality (five in the illustrated <N).
[0021]
(3) when viewed from the slave station, the relay station 15 ₁ to 15 _m is as having a communication function equivalent to that of conventional master station and without communicable distinguished from the master station.
[0022]
(4) relay station 15 ₁ to 15 _m, in place of the conventional master station communicates with each of the slave station, and transmits the contents through the relay station 15 ₀ to the master station.
[0023]
(5) between the relay station 15 ₁ to 15 _m and the master station 11 can communicate with high-speed transmission path than the transmission path between the master station and the slave station (transmission path A), or with the slave station In communication, it is assumed that the relay station can efficiently communicate at the same transmission speed as the transmission path between the master station and the slave station by editing and aggregating the information of the slave stations.
[0024]
(6) when the internal relay station 15 ₁ to 15 _m is provided with a cut switch the transmission path, an abnormality in the transmission path between the relay station or master station - repeater station (transmission line B) occurs this By switching the switch, the information can be transmitted between the master station and the slave stations through the transmission path A in the same communication procedure as before.
[0025]
The communication according to the present embodiment is, for example, as shown in FIG. The figure, the relay station 15 ₁ collects a plurality of slave stations 12 ₁ to 12 ₅ and the contents in the polling communication to be relayed, shows only the portion to be transmitted to the master station via the relay station 15 _0. Similarly, in another relay station 15 ₂ to 15 _m, each of which transmits the contents through the relay station 15 ₀ to the polling communication with the slave station and relayed to the master station. The collection of slave station information by each of the relay stations is performed in parallel in time, so that the time finally transmitted to the master station is polling communication for the number of slave stations per relay station (five in the figure). Is reduced to the same extent.
[0026]
Furthermore, in the communication with the slave station, if the relay station edits and aggregates the information of the slave station, the number of bits required to transmit information from the relay station to the master station can be reduced. Even with transmission lines of the same speed, the time can be further reduced.
[0027]
Further, by switching the transmission path separation switch inside the relay station, direct communication can be performed between the master station and the slave station, and when the relay station or the transmission path between the master station and the relay station is abnormal, the communication between the master station and the slave station is performed directly. Backup operation by communication is possible. Also, by switching the transmission path separation switch inside the relay station, depending on the communication content between the master station and the slave station, the direct communication method between the master station and the slave station and the master station to the relay station to the slave station can be used. The communication system via the relay station can be switched.
[0028]
【The invention's effect】
As described above, the present invention has the following effects.
[0029]
(1) Each relay station collects information on each slave station to be relayed in parallel in time, and sequentially transmits the slave station information collected by the relay station to the master station. Even though a simple polling communication method is used between relay stations, each relay station can collect information from all of the slave stations in a shorter time than the conventional method.
[0030]
(2) Since the relay station edits and aggregates information of a plurality of slave stations, the number of bits required for transmitting information from the relay station to the master station can be reduced. Data can be transmitted to the master station in a shorter time than in the conventional method.
[0031]
(3) Communication is performed between the relay station and the slave station using the same transmission method as in the related art. Therefore, the replacement and modification of the slave station is unnecessary, and the transmission path between the relay station and the slave station can be diverted from the conventional transmission path. The cost of replacement work can be reduced.
[0032]
(4) By switching the transmission path separation switch inside the relay station, direct communication can be performed between the master station and the slave station. Thus, when the relay station or the transmission path between the master station and the relay station is abnormal, the backup operation can be performed by directly communicating between the master station and the slave station.
[0033]
(5) By switching the transmission path separation switch inside the relay station, direct communication can be performed between the master station and the slave station. Thereby, it is possible to switch between the direct communication system between the master station and the slave station and the communication system via the relay station such as the master station to the relay station to the slave station according to the communication content between the master station and the slave station.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an embodiment of the present invention.
FIG. 2 is an information transmission time chart in the embodiment.
FIG. 3 is a system configuration diagram of a multi-drop system.
FIG. 4 is a time chart of a conventional polling process.
FIG. 5 is a time chart of a conventional group division.
FIG. 6 is a procedural diagram of a distribution line reclosing method.
[Explanation of symbols]
1 ... master station ₂ 1 to 2 N _... slave station 11 ... master station ₁₂ 1 _{to 12 5, 131-134} 5, ₁₄ 1-14 5 _... slave station ₁₅ 0-15 5 _... relay station

Claims (4)

In a remote monitoring control system for communicating between a master station and N slave stations via a multi-drop communication channel and transmitting information of the slave station having "information to be transmitted" to the master station,
A relay station having a communication function equivalent to the master station is arranged between the master station and the slave station,
Adjust the number of slave stations to be relayed by each relay station to an appropriate number,
Each relay station collects information on each slave station to be relayed in parallel in time,
A remote monitoring control system characterized by sequentially transmitting slave station information collected by each relay station to a master station. 2. The remote monitoring control system according to claim 1, wherein the relay stations collect and edit information on slave stations to be relayed, reduce the number of bits of information, and transmit the information to the master station. 3. 3. The relay station according to claim 1, wherein the relay station is provided with a transmission path changeover switch therein, and communication between the master station and each of the slave stations is enabled without a relay station by switching the switch. 4. The remote monitoring control system as described. The switching of the switch is performed by switching between a direct communication method between a master station and a slave station and a communication method via a master station, a relay station, and a slave station and a relay station depending on the content of communication. 3. The remote monitoring control system according to 1.

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