CN201307149Y - System for monitoring temperature of cable head and automatically positioning line fault of ring main unit - Google Patents

Abstract

The cable head temperature monitoring and line fault automatic positioning system of the ring network cabinet belongs to the automatic monitoring device of the remote monitoring system. Including the monitoring center, transmission network and field equipment, the comprehensive monitoring device is installed in the ring network cabinet, the fault indicator is installed on the cable, the output signal of the fault indicator is connected to the digital input terminal of the comprehensive monitoring device, the cable temperature probe and the integrated The monitoring device is connected, and the comprehensive monitoring device is connected to the monitoring center through a wired transmission network/GPRS. It can monitor various indicators of the operating environment of distribution network equipment in real time, and can record, query, and automatically and quickly alarm in case of emergency situations such as excessive cable temperature. When the line fails, it can automatically report the fault location, and the system can automatically locate it through software analysis, quickly find the fault section, isolate the fault, and restore power supply as soon as possible.

Description

Cable Head Temperature Monitoring and Line Fault Automatic Locating System of Ring Network Cabinet

technical field

The cable head temperature monitoring and line fault automatic positioning system of the ring network cabinet belongs to the automatic monitoring device of the remote monitoring system.

Background technique

With the progress of society and the continuous improvement of informatization and automation, people's dependence on the power industry has further deepened, and higher requirements have been placed on the reliability of the power supply system. However, due to the complexity of the power distribution network and long line distances, line faults are inevitable. After a fault occurs, the ability to quickly restore power supply has become an important concern of the power supply department.

In addition, with the increase of power consumption, the phenomenon of overheating of many cable joints in the distribution network occurs from time to time due to problems such as long running time and manufacturing process. Such as ring network cabinets, box transformers and other operating environments are harsh and unattended, and it is not easy to be found after local overheating of the cables. The accident spread will cause major accidents, affect normal production, and cause major economic and reputation losses to power companies. Therefore, the prevention of accidents is the foundation of safe production, and the next step in the development of automation is from troubleshooting to condition-based maintenance.

At present, fault indicators are widely used in power distribution lines, but once a line fault occurs, the indicators in the fault area will flip, requiring line maintenance personnel to patrol the line to determine the location of the fault, making the fault treatment not timely enough.

Utility model content

The technical problem to be solved by the utility model is: in order to ensure the safe and normal operation of the distribution network, real-time monitoring of various indicators of the operating environment of the distribution network equipment, in case of emergency accidents such as high cable temperature, timely recording, query and automatic rapid alarm . When the line fails, it can automatically report the fault location, and the system can automatically locate it through software analysis, quickly find the fault section, isolate the fault, and restore the power supply as soon as possible. The cable head temperature monitoring and line fault automatic positioning system of the ring network cabinet.

plan

The technical scheme adopted by the utility model to solve its technical problems is: the cable head temperature monitoring and line fault automatic positioning system of the ring network cabinet, which is characterized in that: it includes a monitoring center, a transmission network and field equipment, and the comprehensive monitoring device is installed in the ring network cabinet. In the network cabinet, the fault indicator is installed on the cable, the output signal of the fault indicator is connected to the digital input terminal of the comprehensive monitoring device, the cable temperature probe is connected to the comprehensive monitoring device, and the comprehensive monitoring device is connected to the monitoring center through the wired transmission network/GPRS connected.

The comprehensive monitoring device includes CPU and peripheral expansion circuit, RAM; switching value input circuit and conditioning circuit connected with the switching value input circuit, clock circuit, communication circuit, CPU and peripheral expansion circuit are respectively connected with analog quantity input circuit and analog quantity input circuit The connected conditioning circuit and A/D conversion circuit; the switching value input circuit and the conditioning circuit connected to the switching value input circuit, the clock circuit, the communication circuit and the RAM are connected.

The network short message server is connected with the database server through the local area network.

The fault indicator uses the electromagnetic field change generated by the fault current to generate a pulse signal to stimulate the circuit to work without affecting the normal operation of the power grid.

working principle

The monitoring device adopts a low-power microcontroller, which monitors the operating status of the cable in real time by collecting the temperature of the probe installed on the cable, and confirms whether there is a temperature rise accident by comparing and judging, and judges by collecting the signal of the sensor Whether there is a line failure. Once an alarm occurs, the monitoring device will immediately start the sending process and send the alarm information to the monitoring center. The monitoring center notifies relevant personnel through text messages or screen prompts, etc., and immediately handles the fault, thus ensuring the safe operation of the distribution network.

The system consists of three parts, one is the monitoring center, the other is the transmission network, and the third is the field equipment. The monitoring center is equipped with data servers, front workstations, browsing terminals, network SMS servers, etc. It is mainly responsible for receiving data from each monitoring point, and realizing functions such as data storage, analysis, judgment, and alarm, and reminding relevant staff in different ways Work on site. The transmission network adopts the local area network within the system, or if the conditions are not met, the GPRS communication network is used to mainly complete the data transmission function.

The comprehensive monitoring device is installed in the ring network cabinet to monitor the temperature of the cable head, the fault indicator is installed on the cable, and the output signal of the fault indicator is connected to the digital input terminal of the comprehensive monitoring device. General-purpose products are selected for the fault indicator, but it must have an alarm information output interface for easy access to the comprehensive monitoring device.

The system mainly uses technologies such as computer, communication, network, telemetry, and remote signaling to form an integrated network monitoring system. The information of monitoring points can be seen on the computer screen, which improves the reliable operation of the distribution network, improves maintenance efficiency, and reduces Maintenance cost and labor intensity make the gradual transition from "regular maintenance" to "conditional maintenance".

Through the implementation of this system, the temperature rise of the cables in the ring network cabinet and the alarm of the fault indicator can be found in time. When the temperature rises to a certain limit, the alarm will be issued immediately to remind the user to take measures to avoid accidents. The safety of the distribution network operation is greatly improved, and when the line fails, the fault information can be automatically reported. The system automatically determines the fault location through software analysis, quickly finds the fault, restores the power supply in time, and improves the reliability of the power supply.

Compared with the existing technology, the beneficial effects of the cable head temperature monitoring and line fault automatic positioning system of the ring network cabinet are: the temperature measurement unit adopts the latest microelectronic technology, and the microcontroller is used to measure the temperature. The construction is simple and the operation is easy. Reliable; multi-point measurement at the same time, high sensitivity;

The data transmission channel adopts mature GPRS network or TCP/IP network, as long as it has GSM signal, it can realize reliable communication.

The temperature limit alarm adopts the method of relative comparison, which solves the difference of temperature alarm limit caused by different line loads and different seasons (winter and summer), which greatly facilitates the use of users.

Multiple ways of alarm: After the system detects the alarm information, it will immediately start the alarm program, including local sound and light alarm, network client alarm, SMS alarm, telephone voice alarm, etc. No matter where you are, you will receive the alarm information at the fastest speed.

The fault indicator has strong anti-interference ability, is not subject to any interference from surrounding electromagnetic fields, and does not have the problem of insulation breakdown. The fault indicator is a new generation of distribution line fault addressing product designed with advanced MCU technology, A/D sampling technology and low power consumption technology. The fault indicator has the characteristics of reliable action, stable performance, and easy judgment. The fault indicator has the ability to detect the magnitude of the load current, identify the surge current change at the moment of line load input, the change rule of the line short-circuit current, and judge the reclosing function. It has the function of accurately judging the line short-circuit fault.

Since the failure is sporadic, the MCU and related circuits enter a sleep energy-saving state under normal conditions; once a failure signal occurs, the micro-control chip and related circuits are immediately awakened, and the setting program is started. After the failure is recovered, the micro-control chip and related circuits re-enter the dormant energy-saving state.

The sensor is passive and detects the signal directly online, and uses the electromagnetic field change generated by the fault current to generate a pulse signal to stimulate the circuit to work without affecting the normal operation of the power grid.

Description of drawings

Fig. 1 is the structure diagram of the cable head temperature monitoring and line fault automatic positioning system of the utility model ring network cabinet;

Fig. 2 is a functional block diagram of the comprehensive monitoring device;

Fig. 3 is a schematic diagram of line fault location;

Fig. 4 is a schematic diagram of the comprehensive monitoring device CPU and peripheral expansion circuit;

Fig. 5 is a schematic diagram of the analog quantity acquisition circuit of the comprehensive monitoring device;

Fig. 6 is a schematic diagram of the switching value acquisition circuit of the comprehensive monitoring device.

Figure 1-6 is the best embodiment of the cable head temperature monitoring and line fault automatic location system of the utility model ring network cabinet.

In Figure 4-6: U1 CPU U2 real-time clock U3 latch U4 RAM U5 decoder U6, U15 bus driver U7 RS232 level converter U8-U10 multi-channel switch U11 operational amplifier U12A\D converter U13, U14 photoelectric Coupler RP1-RP3 Switch N1 Reference Voltage Source R1-R43 Resistor C1-C19 Capacitor J1-J2 Jumper Terminal X1-X9 Terminal RW1 Potentiometer V1-V2 Diode V3 Regulator Tube BAT1 Button Battery.

Detailed ways

The following is a further description of the cable head temperature monitoring and line fault automatic positioning system of the utility model ring network cabinet in conjunction with Figures 1-6:

Referring to Figure 1:

The cable head temperature monitoring and line fault automatic positioning system of the utility model ring network cabinet is composed of three parts: monitoring center, transmission network and field equipment. The monitoring center is composed of database server, browsing terminal, operating terminal, local area network, network short message server, pre- Composed of workstations, the transmission network is a wired transmission network/GPRS, the comprehensive monitoring device is installed in the ring network cabinet, the fault indicator is installed on the cable, the output signal of the fault indicator is connected to the digital input terminal of the comprehensive monitoring device, and the cable temperature probe Connected with integrated monitoring device. The comprehensive monitoring device is connected with the front workstation of the monitoring center through the wired transmission network/GPRS.

Referring to Figure 2:

The comprehensive monitoring device includes CPU and peripheral expansion circuit, RAM; switching value input circuit and conditioning circuit connected with the switching value input circuit, clock circuit, communication circuit, CPU and peripheral expansion circuit are respectively connected with analog quantity input circuit and analog quantity input circuit The connected conditioning circuit and A/D conversion circuit; the switching value input circuit and the conditioning circuit connected to the switching value input circuit, the clock circuit, the communication circuit and the RAM are connected.

Referring to Figure 3:

The method of automatic fault location: Substation A sends out a distribution network line through outlet circuit breaker B, and installs fault indicators 1, 2, 3, 4, 5, 6, 7, 8, etc. in different sections of the line. If a short-circuit fault occurs between the fault indicators 5 and 8, the fault indicators 1, 2, 4, and 5 all have alarm outputs, while the other fault indicators have no alarm output. The monitoring center automatically locates the fault point between the fault indicators 5 and 8 through software analysis and judgment based on the received alarm information of the fault indicators 1, 2, 4, and 5.

Referring to Figure 4:

The CPU and peripheral expansion circuit are composed of CPU U1, crystal oscillator XT1, latch U3, decoder U5, bus driver U6, dial switch SW1, resistor row RP1, RP2, the data lines AD0-AD7 of CPU U1 and the latch U3, the B0-B7 of the bus driver U6, and the resistance bank RP1 are connected; the 2 and 3 pins of the decoder U5 are respectively connected with the 12 and 7 pins of the CPU U1, and the 14 and 13 pins of the decoder U5 are connected with the 9 pins of the CPU U1 respectively. , 8 pins are connected, A0-A7 of the bus driver U6 is connected with the dial switch SW1 and the resistance bank RP2, the other end of the dial switch SW1 is grounded, and the crystal oscillator XT1 is connected with the 20 and 21 pins of the CPU U1; the models used by each chip are : CPU U1 STC89C54-PLCC44, real-time clock U2 PCF8563T, latch U3 74HCT573, RAM U4 HM62256BLFP, decoder U5 74HCT139, bus driver U6, U15 74HCT245, U7 RS232 converter multi-channel switch U8-U10 is 4051, U11 MCP6002 , A/D conversion U12 MCP3221 U13, U14 are optocoupler TLP521.

The communication circuit includes RS232 level converter U7, DB9 head XS1, and capacitor C3-C7; pins 11 and 13 of CPU U1 are connected to pins 12 and 11 of RS232 level converter U7; pins 1 and 3 of RS232 level converter U7 Connect a capacitor C3 between pins, connect a capacitor C4 between pins 4 and 5, connect a capacitor C5 between pins 2 and 16, connect a capacitor C6 between pins 6 and 15; RS232 level converter U7 14, The 13 pins are respectively connected to the 3rd and 2nd pins of the DB9 header XS1, and the 5th pin of the DB9 header XS1 is grounded;

The clock circuit includes real-time clock U2, crystal oscillator XT2, diodes V1 and V2, button battery BAT1, and resistors R1-R3; pins 1 and 2 of real-time clock U2 are connected to both ends of crystal oscillator XT2, and pins 3, 6, and 5 are each connected to an upper Pull resistors R1, R2, and R3 are respectively connected to pins 14, 17, and 23 of CPU U1;

RAM includes RAM U4; data lines AD0～AD7 of CPU U1 are connected with data lines D0～D7 of RAM U4; address bus A8～A15 of CPUU1 is connected with A8～A14 and /CE of RAM U4; Q0～ Q7 is connected to A0~A7 of RAMU4; /RD and /WR of CPU U1 are connected to /OE and /WE of RAM U4 respectively.

Referring to Figure 5:

The analog quantity input circuit is composed of multi-way switch U8-U10, operational amplifier U11, A\D converter U12, reference voltage source N1, resistors R7-R35, capacitor C7-C11, regulator tube V3, multi-way switch U8-U10 The ABC terminals are respectively connected to pins 15, 16, and 6 of the CPU U1, the INH terminals of the multi-way switch U8-U10 are respectively connected to pins 4, 5, and 6 of the decoder U5, and the X terminals of the multi-way switches U8-U10 are connected to Connect to pin 3 of operational amplifier U11 together, pin 1 and pin 2 of operational amplifier U11 are connected, and connect to pin 3 of A\D converter U12 through resistor R33, pin 5 and pin 4 of A\D converter U12 are connected to CPU Pin 17 and pin 23 of U1; pin 2 of reference voltage source N1 is connected to pin 1 of A\D converter U12; X0-X7 of multi-way switch U8-U10 is the signal input terminal, connected to 18-way temperature acquisition signal, 2 channel analog signal.

Each channel of temperature acquisition signal is connected to terminal X1-X8 through a resistor, and each channel is connected to ground through a resistance-capacitance network composed of a resistor and a capacitor connected in parallel.

Referring to Figure 6:

The switching value input circuit is composed of photocoupler U13, U14, bus driver U15, resistors R36-R43, capacitors C12-C19, resistor row RP3, terminal X9, X10, and pin 1 of terminal X9 is connected to the photoelectric coupler through resistor R36

Pin 2 of photocoupler U13, pin 1 of optocoupler U13 is connected to the power supply, pin 1 and pin 2 of photocoupler U13 are connected in parallel with capacitor C12, pin 16 of optocoupler U13 is connected to pin 2 of bus driver U15, pull up The resistor bank RP2 is respectively connected to A0-A7 of the bus driver U15, and B0-B7 of the bus driver U15 is connected to the data bus AD0-AD7 of the CPU U1.

There are 8 switch input circuits.

work process

The temperature probe is installed on the cable, and as the temperature changes, the output signal of the temperature probe changes accordingly. The signal enters the multi-way switch U8-U10 through the conditioning circuit, and is controlled by CPU U1 to select one way for A/D conversion, read the converted data, and obtain the actual temperature value through conversion. The program judges whether the temperature exceeds the limit by analysis. Once the temperature exceeds the limit, the sending process is started immediately, and the alarm information is sent to the monitoring center through the communication channel. After the alarm signal of the fault indicator is isolated by the photocoupler U13\U14, it is read by the CPU U1, and the program compares and judges whether there is an alarm. Once an alarm is found, the sending process is started immediately, and the alarm information is sent to the monitoring center through the channel.

After the monitoring center receives the alarm information, it will automatically analyze and judge. If it is a high temperature alarm, the alarm information will be sent to the mobile phone of the relevant personnel through the network short message server immediately, indicating that there is an alarm, please deal with it immediately. If it is fault information, it will analyze and judge according to the topology of the fault line, automatically locate the fault section, and send the judgment result to the mobile phone of the relevant personnel to prompt an alarm. In addition, the IE browser terminal in the system can also receive the alarm information and prompt it on the computer screen. So far, an alarm message has been processed.

Functions realized by the system:

a. Temperature acquisition function

By installing probes for continuous temperature measurement on cables and cable joints, the running status of cables and cable heads can be monitored in real time, and the measurement results can be uploaded to the monitoring center database server through the communication network, and the early overheating of cables can be predicted in advance through software analysis Phenomenon, realize the early prediction of cable faults, prevent problems before they happen, and achieve the function of early warning.

b. Line fault automatic location function

When a short-circuit fault occurs on the line, the fault indicator quickly judges and outputs an indication signal, and the signal is sent to the monitoring device. The monitoring device detects the signal and immediately sends it to the monitoring center. Through the analysis and judgment of the monitoring center, the faulty section of the line can be quickly found , isolate the fault, and restore power as soon as possible.

c. Communication function

The monitoring device is connected with the monitoring center through the GPRS channel, and the GPRS is provided by a professional operator to ensure reliable communication.

d. Data processing function

The comprehensive monitoring device judges whether there is a temperature rise by comparing the collected data of the three phases A, B, and C, thereby avoiding the problem of different temperature limits caused by different seasons and different ambient temperatures. By comparing with historical data, determine whether there is a line fault alarm. System configuration data, alarm information, etc. are all stored in the database, which is convenient for statistical analysis; various statistical reports and charts can be generated according to user requirements. According to the different topological locations and alarm types of the alarm, it provides data analysis function to determine the cause and location of the fault.

e.Alarm function

When a line fails or the temperature of the cable or cable head rises and exceeds the set alarm limit for some reason, the monitoring device immediately starts the sending process and sends the alarm information to the monitoring center. The monitoring center will send out alarms in different ways, including network alarm client, SMS, etc., and display the location of the alarm point and record the time when the alarm occurred, so as to guide the maintenance and fault finding work in a timely and accurate manner.

f. System management function

The main control unit, acquisition equipment, monitoring points, operators, system functions, etc. can be configured; the system log records the system status and personnel operations in detail.

g. Historical alarm search function

The system provides a convenient historical alarm search function, the user can query the database according to the line or time, and the query result can be converted into an EXCEL form, which is convenient for the user.

h.WEB publishing function

At any place and any time, as long as you can access the Internet and have the corresponding authority, you can monitor the operating status of the system. The control right can only be in the local monitoring center to ensure safe operation.

i. Security management function

User management: add or delete the list of management personnel, management authority settings, etc.; the system divides users into system administrators, general operators, line maintenance personnel, browsing users, etc. according to different functions, and sets different user settings for different users. Permissions, only certain permissions can perform certain operations. Operation log: record the operation events and time of each log-in person; modify password: allow the logged-in user to modify his password; log-in and logout: the user exits the monitoring software.

Claims (8)

1, monitoring of the cable head temperature of ring main unit and line fault automatic station-keeping system, it is characterized in that: comprise Surveillance center, transmission network and field apparatus, integrated monitoring apparatus is installed in the ring main unit, fault detector is installed on the cable, the output signal of fault detector is connected to the switching value input end of integrated monitoring apparatus, the cable temperature probe links to each other with integrated monitoring apparatus, and integrated monitoring apparatus links to each other with Surveillance center by wire transmission network/GPRS.

2, the cable head temperature of ring main unit according to claim 1 monitoring and line fault automatic station-keeping system is characterized in that: integrated monitoring apparatus comprises CPU and peripheral expansion circuit, RAM; Switching value input circuit and the modulate circuit, clock circuit, the telecommunication circuit that link to each other with the switching value input circuit, CPU and peripheral expansion circuit reach modulate circuit, the A/D change-over circuit that links to each other with simulated measurement input circuit with simulated measurement input circuit respectively; Switching value input circuit and the modulate circuit that links to each other with the switching value input circuit, clock circuit, telecommunication circuit, RAM link to each other.

3, monitoring of the cable head temperature of ring main unit according to claim 1 and line fault automatic station-keeping system, it is characterized in that: the network and short message server of Surveillance center links to each other with database server by LAN (Local Area Network).

4, monitoring of the cable head temperature of ring main unit according to claim 2 and line fault automatic station-keeping system, it is characterized in that: CPU and peripheral expansion circuit are made up of CPU U1, crystal oscillator XT1, latch U3, code translator U5, bus driver U6, toggle switch SW1, resistor chain RP1, RP2, and the data line AD0-AD7 of CPU U1 links to each other with B0-B7, the resistor chain RP1 of latch U3, bus driver U6; 2,3 pin of code translator U5 link to each other with 12,7 pin of CPU U1 respectively, 14,13 pin of code translator U5 link to each other with 9,8 pin of CPU U1 respectively, the A0-A7 of bus driver U6 links to each other with toggle switch SW1, resistor chain RP2, the other end ground connection of toggle switch SW1, crystal oscillator XT1 links to each other with 20,21 pin of CPU U1;

Telecommunication circuit comprises RS232 level translator U7, a DB9 XS1, capacitor C 3-C7; 11,13 pin of CPU U1 link to each other with 12,11 pin of RS232 level translator U7; Connect between 1,3 pin of RS232 level translator U7 to connect between capacitor C 3,4,5 pin to connect between capacitor C 4,2,16 pin and connect a capacitor C 6 between capacitor C 5,6,15 pin; 14,13 pin of RS232 level translator U7 are connected respectively to 3,2 pin of DB9 XS1, the 5 pin ground connection of DB9 XS1;

Clock circuit comprises real-time clock U2, crystal oscillator XT2, diode V1, V2, button cell BAT1, resistance R 1-R3; 1,2 pin of real-time clock U2 are connected to the two ends of crystal oscillator XT2, and 3,6,5 pin respectively are connected respectively to 14,17,23 pin of CPU U1 by pull-up resistor R1, R2, a R3;

RAM comprises RAM U4; Data line AD0～AD7 of CPU U1 links to each other with data line D0～D7 of RAM U4; Address bus A8～A15 of CPUU1 and A8～A14 of RAM U4 ,/CE links to each other; Q0～Q7 of latch U3 links to each other with A0～A7 of RAMU4; CPU U1 /RD ,/WR respectively with RAM U4 /OE ,/WE links to each other.

5, the cable head temperature monitoring and the line fault automatic station-keeping system of ring main unit according to claim 2, it is characterized in that: simulated measurement input circuit is by multi-way switch U8-U10, operational amplifier U11, A D converter U12, reference voltage source N1, resistance R 7-R35, capacitor C 7-C11, stabilivolt V3, the ABC end of multi-way switch U8-U10 is connected respectively to 15 of CPU U1,16,6 pin, the INH end of multi-way switch U8-U10 is connected respectively to 4 of code translator U5,5,6 pin, the X end of multi-way switch U8-U10 also is connected to 3 pin of operational amplifier U11 together, 1 of operational amplifier U11,2 pin link to each other, and by resistance R 33 be connected to A 3 pin of D converter U12, A D converter U12 5,4 pin are connected to 17 of CPU U1,23 pin; 2 pin of reference voltage source N1 be connected to A 1 pin of D converter U12; The X0-X7 of multi-way switch U8-U10 is a signal input part, inserts 18 road temperature acquisition signals, 2 tunnel simulating signals.

6, monitoring of the cable head temperature of ring main unit according to claim 5 and line fault automatic station-keeping system, it is characterized in that: each road temperature acquisition signal is connected on the connection terminal X1-X8 by a resistance, and each road all is connected to ground by the resistance-capacitance network that a resistance and electric capacity compose in parallel.

7, the cable head temperature monitoring and the line fault automatic station-keeping system of ring main unit according to claim 2, it is characterized in that: the switching value input circuit is by photoelectrical coupler U13, U14, bus driver U15, resistance R 36-R43, capacitor C 12-C19, resistor chain RP3, connection terminal X9, X10 forms, 1 pin of connection terminal X9 is connected to 2 pin of photoelectrical coupler U13 by resistance R 36,1 pin of photoelectrical coupler U13 connects power supply, 1 of photoelectrical coupler U13, between 2 pin and connect capacitor C 12,16 pin of photoelectrical coupler U13 are connected to 2 pin of bus driver U15, pull-up resistor row RP2 is connected respectively to the A0-A7 of bus driver U15, and the B0-B7 of bus driver U15 is connected to the data bus AD0-AD7 of CPU U1.

8, monitoring of the cable head temperature of ring main unit according to claim 7 and line fault automatic station-keeping system, it is characterized in that: the switching value input circuit is 8 the tunnel.

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