JP2001264356A - Monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer data by measuring/weighing electric quantities around a transformer using a power line carriage technology, and to assure information at a switcher wherein a power must be supplied from a post stage of a switching mechanism. SOLUTION: A CPU of a switcher 5 is provided with a backup power source while power source monitoring devices 7 and 8 are provided to a high-voltage side and low-voltage side of a transformer 2, respectively, for measuring/ weighing electric quantities around the transformer while power-source monitoring devices are cascaded for communication with power line carriage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the measurement and measurement of various quantities of electricity in a distribution substation system or the monitoring of equipment status, transmission of such information to a higher-level device, and the higher-level device performs predetermined processing. Related to monitoring systems.

[0002]

2. Description of the Related Art In a power distribution monitoring system for a distribution substation, various measurement sensors and meters are used in a system to measure and measure various electric quantities and to monitor or control on / off information and the like. Information management is performed by recording and storing measurement / weighing results, monitoring information results, and control results.

FIG. 7 shows an example of a conventional power distribution monitoring system for a distribution substation. 1 is the power receiving side main line of the power receiving and distribution system,
2 is a transformer, 3 is a main line on the distribution side, 4 is a distribution side bus, 5 is a switch, and 6 is a load. The power receiving side main line 1 of the power receiving and distribution system is provided with a current transformer (CT sensor) 20 as a sensor for capturing a current signal and a transformer (VT sensor) 21 as a sensor for capturing a voltage signal. Device 11
Connected to. The power supply monitoring device 11 includes a communication unit.
In addition, 22 is an ammeter. In the switch 5 of each load 6,
It measures and measures the amount of electricity of the load and has a communication unit. A communication line 13 is provided to cascade-connect each of the above communication units, and each measurement result is transmitted to the host device 10. In addition, 14 is a signal converter. As described above, even in the same premises, the power supply monitoring device 11 and the switch 5 are installed in a remote location and measure the amount of electricity and detect the open / closed state of the circuit. It is connected and forms a monitoring system. Further, the switch 5 has a function of automatically shutting off a circuit in response to an overcurrent, for example.

[0004] In such a monitoring system, there is a problem that the number of wirings for connecting the constituent devices, devices, and the like increases, and the workability is poor and uneconomical.

In recent years, proposals have been made to solve this main problem. For example, Japanese Patent Application Laid-Open No. 05-174693 has been proposed.
In Japanese Patent Application Laid-Open No. Hei 8-226940, a sensor and a data transmission circuit are incorporated, and information is transmitted to a host device via a communication line to reduce the number of wirings.

Further, there is a method for further reducing the number of wiring steps by using a power distribution line to eliminate the communication line as described above and using a power line transportation technique. There is a problem that a communication signal is obstructed or cut off by a transformer in the inside, and as known examples of solving this problem, Japanese Patent Application Laid-Open Nos. 62-35724 and 1-276.
No. 933 has been proposed and solved by a device for bypassing between transformers.

Japanese Patent Laid-Open Publication No. Sho 62-104231 is an example in which a bypass device (slave station) has a function of monitoring a terminal device.

[0008]

In each of the examples using the power line carrier technique, the communication signal at the transformer is bypassed, and various electric quantities around the transformer are measured and measured. Has to be provided with a terminal device, which is uneconomical.

In addition, when a switch has an electronic circuit such as a transmission unit, power supply is indispensable.
That is, in consideration of shutting off when an overcurrent occurs at the subsequent stage of the opening / closing mechanism, power must be supplied from the stage subsequent to the opening / closing mechanism. There is a problem that the information is interrupted or incorrect. The present invention is to solve these problems.

[0010]

According to the present invention, signal transmission between devices is carried out by power line communication.
A small computer equipped with a CPU having a necessary processing program and a necessary memory is arranged in each device, and signals required for each device are collectively processed by the computer. Further, the computer is provided with a power supply unit for supplying power from a power line so that signals can be transmitted and received for a short time even if power is shut off.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG.

FIG. 1 shows a configuration diagram of a monitoring system according to an embodiment of the present invention. 1 is a power receiving side main line of a power distribution system, 2 is a transformer, 3 is a power distribution side main line, 4 is a power distribution side bus, and 5 is a switch according to the present invention, which will be described later. Reference numeral 6 denotes a load, which schematically shows a load connected to a distribution line provided through the switch 5. Reference numerals 7 and 8 denote power supply monitoring devices provided on the load side and the power supply side, respectively. Reference numeral 10 denotes a host device, which uses a general-purpose personal computer having a necessary processing program. 9 is a signal converter, as described later,
It is provided to transmit a signal from the power monitoring devices 7 and 8 and each switch 5 to the host device 10, or conversely, to transmit a signal from the host device 10 to the power monitoring devices 7 and 8 and each switch 5. The general-purpose personal computer 10 communicates with R
S-232C is common, and the signal converter 9 is R
The connection is made with an S232C cable.

Reference numerals 7-1 and 8-1 denote current transformers (CT sensors) for capturing current signals, and reference numerals 7-2 and 8-2 denote transformers (VT sensors) for capturing voltage signals. The power supply monitoring devices 7 and 8 are provided to introduce current and voltage signals on the load side and the power supply side provided with the power supply monitoring devices 7 and 8 to the power supply monitoring devices 7 and 8, respectively. Reference numeral 7-11 denotes a carrier unit for injecting and extracting a power line carrier signal, and is provided for coupling a load side and a power supply side by a signal, as described later.

FIG. 2 is a block diagram showing an example of a specific configuration of the switch 5 according to the embodiment of the present invention. Reference numeral 5-2 denotes a terminal block for connection to the power receiving side, that is, each branch line branched from the bus 4, and reference numeral 5-3 denotes a load side terminal block. 5-1 is an opening / closing control unit, and 5-100 is an opening / closing mechanism unit. 5-101 is a plurality of CT sensors, 5-102 is a rectifier circuit for rectifying a current signal, 5-103 is a current / power supply circuit for detecting overcurrent and supplying necessary power to the switching control unit 5-1. , 5
Reference numeral -104 denotes an opening / closing mechanism unit 5 when a predetermined overcurrent is detected.
An instantaneous trip circuit for driving a tripping device for instantaneously tripping 100; 5-105, a tripping device;
Reference numeral 06 denotes a time limit for driving a trip device for tripping the opening / closing mechanism unit 5-100 by a predetermined time characteristic when a current smaller than the predetermined overcurrent but exceeding a preset overcurrent is detected. A trip circuit unit, 5-107 is a time limit characteristic setting unit for setting a time limit characteristic, and 5-108 is an alarm display unit for notifying outside when an overcurrent or the like occurs.
Furthermore, 5-4 is a plurality of VT sensors for measurement, 5-5 is a plurality of CT sensors for measurement, and 5-6 is a power supply circuit unit. Reference numeral 5-7 denotes a current / voltage measurement circuit for measuring current / voltage based on the current signal from the CT sensor 5-5 and the voltage signal from the transformer 5-4. 5-15 is a switch monitoring device. Reference numeral 5-8 denotes a CPU unit having a necessary processing program, which has a central function of the switch monitoring device 5-15, and has the following functions. Calculation of electric power and electric energy from the value measured by the current / voltage measurement circuit section 5-7, capture of a signal output from the alarm display section 5-108, the instantaneous trip circuit section 5-104 and the timed trip Taking in the signal output from the circuit unit 5-107, exchanging a signal with the transmission / reception unit 5-12 that converts a power line carrier signal described later into a signal suitable for the internal electronic circuit, and giving a signal to the time limit characteristic setting unit 5-107 , Etc. The CPU unit 5-8 includes a storage unit 5-20, and can store necessary data such as electric power and electric energy. The CPU unit 5-8 is supplied with necessary power from a power supply circuit 5-6. The power supply circuit 5-6 has a super capacitor 5-
9 so that the internal power supply can be backed up when the opening / closing mechanism 5-100 is shut off. The backup time only needs to be at least as long as the communication information immediately before the power interruption and the retransmission information and the power interruption information when a communication failure occurs can be communicated with the host device 10. Naturally, a unique address is set in the CPU section 5-8 of each switch, and the host apparatus 10 and the CPU section 5-8 of each switch communicate using this address. The setting of the unique address can be performed from the host device 10 and, if necessary, can also be performed on site by the setting unit 5-21 provided in the switch 5.
When the setting unit 5-21 is provided, the time-limit characteristic setting unit 5
The setting of -107 can also be performed on site.

Immediately after the terminal block 5-2 on the power receiving side, the transport section 5-
The transport unit 5-13 is provided closer to the terminal block 5-2 than the opening / closing mechanism unit 5-100. Therefore, even if the opening / closing mechanism section 5-100 is disconnected, communication with the power supply monitoring device 7 on the load side can be performed. The transport section 5-13 is connected to the transmission / reception section 5-12. The transmission / reception unit 5-12 converts the power line carrier signal into a signal suitable for the CPU unit and
The signal is introduced into the U section, or the signal of the CPU section is converted into a signal suitable for the power line carrier signal and sent to the carrier section 5-13.

In this embodiment, the CT sensor 5-101 is used.
Have a good characteristic in a predetermined overcurrent region, and the CT sensor 5-5 has a good characteristic in a region below the rated current of the load. By doing so, the protection operation by the switching control unit 5-1 can be performed with high accuracy, and the load measurement can be performed with high accuracy.

FIG. 3 is a block diagram showing a specific configuration of the load-side power supply monitoring device 7 according to the embodiment of the present invention and an example of a connection relationship between the trunk lines 1, 3 and the transformer 2.

Reference numeral 7 denotes a power supply monitoring device main body, 7-1 denotes a CT sensor, 7-2 denotes a VT sensor, 7-3 denotes a power supply unit, and 7-4 measures current and voltage from signals from the CT sensor and VT sensor. Current / voltage measurement unit, 7-5 is a CPU unit, 7-6
Is a storage unit, 7-7 is a setting unit, 7-9 is a transmission / reception unit on the main line 1, 7-11 is a transmission unit for injecting and extracting a power line carrier signal on the main line 1, and 7-12 is a load unit on the load side. The transmission / reception unit of the trunk line 3, 7-14 is a carrier unit for injecting and extracting a power line carrier signal on the trunk line 3 side of the load side, and 7-15 is a super capacitor, and the circuit breakers 7-16 and 7-17 are shut off. Sometimes, this is to back up the internal power supply. The figure
In FIG. 1, the circuit breakers 7-16 and 7-17 are not displayed, but in general, a protection relay for the transformer (not shown) is provided to protect the transformer from an internal accident of the transformer itself. When this worked, the breaker 7-1
6, 7-17 are shut off.

The function of each component block of the power supply monitoring device 7 shown in FIG. 3 is to measure the current and voltage on the load side of the transformer 2 and to send data to the CPU unit 7-5 in the same manner as the switch 5. The passing point is not essentially different from that shown in FIG. However, the power supply monitoring device 7 is provided across the main line 1, the transformer 3, and the main line 3 on the load side, transfers a signal from the main line 1 to the switch 5, and transmits a signal from the switch 5 to the main line 1. Is essentially different from the switch 5 in that it has a function of transferring the data to the switch 5. Transmission / reception units 7-9 and 7-12 connected to the conveyance units 7-1 and 7-14 are provided for that purpose. In the illustrated embodiment, the signals received by the transmission / reception units 7-9 and 7-12 are temporarily sent to the CPU unit 7-5 to determine the signal content, and are then sent out again. The transmission / reception units 7-9 and 7-12 are integrated, and the signals on the main line 1 and the main line 3 on the load side are transferred to each other in response to reception, while being transferred by the CPU unit 7-5. Necessary processing for the signal may be performed. However, in this case, there is a possibility that the signals of the trunk line 1 and the load side of the trunk line 3 may simultaneously reach the transmission / reception unit and cause a signal collision. It is better to make the register for receiving the data independent.
Then, at that time, the CPU section 7-5 may determine the situation and perform necessary transfer control.

The power supply monitoring device 8 shown in FIG. 1 is essentially the same as the power supply monitoring device 7, but needs to have a function of connecting the main line 1 to the host device 10. Therefore, a contrivance is required to have the transport unit 7-11 that can be coupled to the signal converter 9. For this purpose, a transport unit 7-14 connected to the trunk line 1 is provided, and the transport unit 7-11 is provided on a power supply line that is an AC power supply of the host device 10. Then, it is convenient to transmit and receive signals by incorporating the carrier unit and the transmission / reception unit in the signal converter 9 and connecting the signal converter 9 to this power supply line.

The operation of the monitoring system will now be described with reference to FIGS. In the following description, it is assumed that addresses are set in advance for each switch 5 and power supply monitoring devices 7 and 8. If the system is in the initial state, the setting may be performed using the setting unit of each switch 5 and the power monitoring devices 7 and 8, or may be performed from the host device 10 using the setting function of the CPU unit of each. .

FIG. 4 shows the measurement and measurement of the address 03 of the switch 5.
It shows the flow of information when acquiring weighing data. First, the host device 10 requests (commands) data. At this time, a data request command including the address 03 is issued. That is, a request for data and address 0
This is a command indicating that the request is directed to No.3. This command is transmitted to all power supply monitoring devices 7 and 8 and each switch 5 as shown by the thick line in the figure. The power monitoring devices 7 and 8 and each switch 5 receiving this command check whether the address included in the command is their own address. If the address is their own, the measured / weighed value is used as response data (response). Return it to the host device 10. This is shown in FIG.

Next, the case where the measurement / weighing data of the power supply monitoring device 7 is acquired will be considered. Since the unique address is 02, the power supply monitoring device 7 issues a command including O2 in the command and transmits the command to all devices. This flow is the same as in FIG. Since the address included in the command matches its own unique address, the power supply monitoring device 7 returns the measurement / weighing data to the host device 10 as a response. This is shown in FIG.

Here, considering the response data (response), the measurement / weighing data has been described in the above description. However, the O of the contact (opening / closing mechanism section 5-100) of the switch 5 is described.
The N / OFF information and the information that can be obtained by the opening / closing control unit 5-1 such as the elapsed value leading to the overcurrent and the overcurrent value can also be sent to the higher order as a response.

In the power supply monitoring device 7 and the like, if the temperature of the transformer is measured, it can be sent to the host device 10 as a response.

[0026]

According to the present invention, even when the main circuit is disconnected via the circuit breaker, the signal link between the host device 10, the power monitoring devices 7, 8 and the switches 5 can be cut off by the power line carrier technology. Since there is no such system, it is possible to ensure system monitoring. In addition, since there is no need to connect each device with a communication line, construction is extremely simplified, and a monitoring system can be economically constructed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a monitoring system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a specific configuration of the switch according to the embodiment of the present invention.

FIG. 3 is a block diagram showing an example of a specific configuration of a load-side power supply monitoring device according to an embodiment of the present invention and an example of a connection relationship between a trunk line and a transformer.

FIG. 4 is a view showing a flow of information when acquiring measurement / weighing data at a switch address 03;

FIG. 5 is a diagram showing a flow of response data in FIG. 4;

FIG. 6 is a diagram showing a flow of response data of the power supply monitoring device.

FIG. 7 is a configuration diagram of a monitoring system for explaining a conventional technique.

[Explanation of symbols]

1: trunk line, 2: transformer, 3: load side trunk line, 4: distribution line, 5: switch, 5-1: switching control section, 5-2: terminal block, 5-3: terminal block, 5- 4: VT sensor, 5-5: C
T sensor, 5-6: power supply circuit, 5-7: current / voltage measurement circuit section, 5-8: CPU section, 5-12: transmission / reception section, 5-
13: transport unit, 5-15: switch monitoring device, 5-20:
Storage unit, 5-21: setting unit, 7, 8: power supply monitoring device, 7
-3: power supply unit, 7-4: current / voltage measurement unit, 7-5: C
PU section, 7-6: storage section, 7-7: setting section, 7-9: transmission / reception section, 7-1, 7-14: transport section, 7-12: transmission / reception section, 7-16, 7-17: Circuit breaker, 10: host device.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hisako Kimura 46-1 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata F-term in Nakajo Engineering Co., Ltd. (reference) 5G064 AA09 AC01 AC09 CA08 CB08 DA01

Claims (3)

[Claims] 1. A monitoring system for a power distribution system, comprising: a power receiving side main line, a transformer, a power distribution side main line, a power distribution side bus, and a switch connected to the power distribution side bus. A first power supply monitoring device provided, a second power supply monitoring device provided on the main line on the power distribution side, a switch monitoring device provided on the switch, and a higher-level device for controlling each of these monitoring devices Each monitoring device receives a current signal and a voltage signal from the monitored object, performs a predetermined calculation, has a CPU unit having a necessary processing program, and is processed by the CPU unit of the switch monitoring device. The signals thus transmitted can be communicated via the CPU section of the second power supply monitoring apparatus and the CPU section of the first power supply monitoring apparatus by power line transport using the electric path of the place where each monitoring apparatus is provided as a communication path. Features Monitoring system for. 2. The monitoring system according to claim 1, wherein the transmission and reception of the carrier signal by the CPU of the second power supply monitoring device is performed by power line carrier outside the circuit breaker of the transformer. 3. The driving power supply for the CPU section of each of the monitoring devices includes at least communication information immediately before the power supply is cut off when power is cut off with an electric circuit open, retransmission information when a communication failure occurs, and 2. The monitoring system according to claim 1, wherein the monitoring system is capable of supplying power required for a short period of time to notify power-off information to a host device.