CN106771842A - A kind of fuse on-line monitoring system - Google Patents

Abstract

The invention discloses a fuse online monitoring system, which includes a detection terminal, a communication terminal and a system master station, and the detection terminal includes a first main processing unit, an electromagnetic field induction unit, and a current and voltage detection unit connected to the first main processing unit , a location information collection unit, a first local communication unit and a first display unit, the electromagnetic field induction unit is connected to the current and voltage detection unit; the communication terminal includes a second main processing unit, and a second main processing unit connected to the second main processing unit Two local communication units, a remote communication unit, and a second display unit; the detection terminal is fixedly installed on each melting tube of the fuse; the detection terminal passes the parameters of the detected fuse through the first local communication unit, the second The two local communication units send it to the second main processing unit of the communication terminal, and the second main processing unit sends it to the system main station through the remote communication unit.

Description

A Fuse Online Monitoring System

technical field

The invention relates to an online monitoring system for a fuse, which belongs to the field of power grid monitoring.

Background technique

At present, fuses have been widely used in medium-voltage distribution lines. The principle mainly depends on the selection of fuses with different rated currents to limit the line current. When a large current fault occurs, the current exceeds the rated current of the fuse, and the fuse The wire fuse cuts off the fault and realizes the protection of the distribution line. These fuses are mainly used for high-current fault protection of power distribution networks and do not have intelligent functions. During the working process of these fuses, the operating status data of the fuse cannot be collected in real time, so it is difficult to judge the performance and quality of the fuse itself, and it is also impossible to grasp the opening and closing status of the fuse and the power-off status of the load carried by it in time. It is also impossible to realize condition-based maintenance according to the operating parameters of the circuit where the fuse is located and the load it carries.

In view of this, the inventor conducted research on this, and specially developed an online monitoring system for fuses, and this case arose from it.

Contents of the invention

The purpose of the present invention is to provide a fuse on-line monitoring system, which can realize the real-time on-line detection of the operating status and parameters of the fuse itself, the line where it is located and the load, and has the characteristics of simple structure, low cost, convenient installation, and flexible communication networking. , which helps to improve the level of condition-based maintenance of equipment, and can also effectively shorten the time for fault finding and improve the reliability of power supply by obtaining the fault location in time.

In order to achieve the above object, the solution of the present invention is:

A fuse online monitoring system, including a detection terminal, a communication terminal and a system master station, the detection terminal includes a first main processing unit, an electromagnetic field induction unit, a current and voltage detection unit connected to the first main processing unit, and a position information An acquisition unit, a first local communication unit and a first display unit, the electromagnetic field induction unit is connected to the current and voltage detection unit; the communication terminal includes a second main processing unit, and a second local communication unit connected to the second main processing unit unit, a remote communication unit, and a second display unit; the detection terminal is fixedly installed on each fuse tube of the fuse; the detection terminal passes the detected parameters of the fuse through the first local communication unit and the second local communication unit The unit is sent to the second main processing unit of the communication terminal, and the second main processing unit sends it to the system main station through the remote communication unit.

Preferably, the first main processing unit and the second main processing unit are controlled by a microprocessor.

Preferably, the electromagnetic field sensing unit adopts a magnetic field sensor, and the position information collecting unit adopts a magnetoresistive sensor.

Preferably, the current and voltage detection unit includes a fault current judgment module and a ground voltage change measurement module. The current and voltage detection unit calculates the size of the AC component and DC component flowing through the fuse based on the induced current; through the fault current judgment module, it automatically detects whether the current change of the short circuit flowing through the fuse or the lightning flash exceeds the fault threshold value , and automatically detect whether the transient capacitive current when grounding exceeds the fault threshold value; through the measurement of the ground voltage change measurement module to measure the discharge current of the wire and the fuse to the ground, the line-to-ground voltage change is calculated.

Preferably, the fault current judgment module includes a signal amplification circuit connected to the induced current, the output terminals of the signal amplification circuit are respectively connected to a DC detection circuit and an AC detection circuit, and the output terminals of the DC detection circuit are connected to a DC component judgment circuit , through the DC detection circuit and the DC component judgment circuit to realize the judgment output of the transient capacitive current threshold; the output terminals of the AC detection circuit are respectively connected to the power frequency signal high current amplitude judgment circuit and the high frequency signal high current amplitude judgment circuit, wherein The AC detection circuit and the power frequency signal large current amplitude judgment circuit realize the power frequency large current sudden change threshold judgment output, and the AC detection circuit and the high frequency signal high current amplitude judgment circuit realize the high frequency high current sudden change threshold judgment output.

Preferably, the ground-to-ground voltage change measurement module includes a capacitance circuit connected to a high-voltage wire, a discharge current measurement circuit for measuring the capacitance current of the capacitance circuit, and an average value sampling circuit connected to the discharge current measurement circuit. The change measurement module obtains the change value of the voltage of the high-voltage wire to the ground.

Preferably, the first local communication unit and the second local communication unit adopt wireless communication or optical fiber communication to establish a data communication channel between the communication terminal and the detection terminal.

Preferably, the remote communication unit adopts SMS, GPRS, 3G or optical fiber communication to realize two-way communication between the communication terminal and the system master station.

Preferably, the communication terminal further includes a data interface unit, the data interface unit adopts one or more of Ethernet, RS232, and RS485, and the data interface unit is used to support local maintenance of equipment, external equipment data access and local data output etc.

The fuse online monitoring system described in the present invention can realize the real-time online detection of the operating status and parameters of the fuse itself, the line where it is located and the load, and has the following advantages:

1) The terminal device uses an analog circuit to detect the current and voltage changes of the power line, and automatically recognizes the fault current and corresponding voltage changes, thereby triggering the first main processor to perform fault analysis and judgment;

2) The terminal device adopts a miniaturized position information acquisition unit to detect the position status change of the terminal device, so as to obtain the position change of the fuse tube in time, judge the opening and closing status of the fuse, and obtain the power-off status of the line;

3) Using wireless or wired communication methods, establish an online fuse monitoring system to realize real-time collection of fuse fault information, operating data, and status data, and realize the intelligence of fuses;

4) The detection terminal is installed on the fuse without external power supply or other equipment, and has a simple structure and low overall power consumption, which can meet the requirements of miniaturization of the terminal device and simple and convenient installation; a short distance can be used between the detection terminal and the communication terminal Wireless communication meets the insulation requirements of lines and equipment.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the block diagram of the online fuse monitoring system of the present embodiment;

Fig. 2 is the detection terminal block diagram of the present embodiment;

Fig. 3 is the block diagram of the fault current judgment module of the present embodiment;

Fig. 4 is the block diagram of the ground voltage change measurement module of the present embodiment;

FIG. 5 is a block diagram of a communication terminal in this embodiment.

detailed description

As shown in Figure 1, a fuse online monitoring system includes a detection terminal 1, and a system master station 3 connected to the detection terminal 1 through a communication terminal 2. Three detection terminals 1 form a group, and use compression springs or cable ties Fixedly installed on the fuse tube of the fuse, respectively measure the change of current and voltage signals of phase A, phase B and phase C of the same group of fuses, so as to measure the line load current and fault current, detect line faults, and detect the melting of the fuse The position of the fuse can be used to judge the opening and closing state of the fuse; the data such as current data, fault type, and the opening and closing state of the fuse are transmitted to the local communication terminal 2 through short-distance wireless communication or optical fiber communication. The communication terminal 2 is used to receive the current data, fault information, fuse opening and closing status and other data of the local detection terminal 1, and transmit them to the system master station 3 through long-distance communication methods such as GPRS/3G wireless communication and optical fiber communication. The system master station 3 is used to receive and process various data uploaded by the communication terminal, and realize functions such as real-time online monitoring of the operating status of lines and fuses, statistical query of historical data, and equipment status maintenance. The detection terminal 1 is installed on the fuse without external power supply or other equipment, and has a simple structure and low overall power consumption, which can meet the requirements of miniaturization of the terminal device and simple and convenient installation; a short circuit can be used between the detection terminal 1 and the communication terminal 2. Distance wireless communication meets the insulation requirements of lines and equipment.

As shown in Figure 2, in this embodiment, the detection terminal 1 includes a first main processing unit 11, an electromagnetic field induction unit 12, a current and voltage detection unit 13 connected to the first main processing unit 11, and a position information acquisition unit 14. The first local communication unit 15, the first display unit 16, the first power supply unit 17, the first data storage unit 18 and the clock unit 19, wherein the electromagnetic field induction unit 12 is connected with the current and voltage detection unit 13, each unit The function is as follows:

1) The first main processing unit 11: based on the current and voltage detection unit 13 to detect the fuse to ground voltage change, fault current and other parameters, to determine the grounding, short circuit or lightning fault of the line; based on the clock unit 19, the event and data time Marking; through the first local communication unit 15, information such as fault type, measurement data, fuse position and opening and closing status are transmitted to the communication terminal 2 in a wireless or optical fiber manner; the first display unit 16 uses LED lights or color display windows Carry out local fault indication;

2) Electromagnetic field induction unit 12: use the high-voltage electromagnetic field around the fuse to obtain the induced current; use the voltage of the fuse to ground and the potential difference of the air medium to obtain the air discharge current of the wire;

3) Current and voltage detection unit 13: Based on the induced current, calculate the size of the AC component and the DC component flowing through the fuse; through the large current mutation judgment circuit, automatically detect whether the current change when the short circuit flowing through the fuse or lightning flashes Exceeds the fault threshold value; through the small current DC component judgment circuit, automatically detects whether the transient capacitive current when grounding exceeds the fault threshold value; calculates the line-to-ground voltage change by measuring the discharge current of the wire and the fuse to the ground quantity;

4) Position information acquisition unit 14: can acquire the position change and position information of the detection terminal 1 fixed on the fuse tube. At present, many types of sensors have been put into commercial use, such as magnetoresistive sensors, which are suitable for devices with small size and high requirements for low power consumption. The terminal device adopts a miniaturized location information acquisition unit to detect the position status change of the terminal device, so as to obtain the position change of the fuse tube in time, judge the opening and closing status of the fuse, and obtain the power-off status of the line;

5) The first local communication unit 15: it can support short-distance wireless communication, optical fiber communication, etc., and provide a data communication channel for the fault detection terminal. Using wireless or wired communication, establish an online fuse monitoring system to realize real-time collection of fuse fault information, operating data, and status data, and realize the intelligence of fuses;

6) The first display unit 16: with LED lights or color display windows, which can be controlled by the main chip to display the corresponding fault status;

7) The first power supply unit 17: obtain electric energy by means of inductive power acquisition, solar power acquisition, backup battery, etc., and provide power for each functional unit;

8) The first data storage unit 18: store the detected relevant data, such as when the local communication is interrupted, it can support resuming or resending;

9) Clock unit 19: It can obtain the time synchronization instruction of the communication terminal 2, provide accurate time synchronization for the main chip of the first main processing unit 11, and ensure that the data collected and uploaded by the detection terminal 1 is synchronized with the system.

In this embodiment, the current and voltage detection unit 13 includes a fault current judgment module and a ground voltage change measurement module. The current and voltage detection unit 13 calculates the size of the AC component and the DC component flowing through the fuse based on the induced current; through the fault current judgment module, it automatically detects whether the current change of the short circuit flowing through the fuse or the lightning flash exceeds the fault threshold value, and automatically detect whether the transient capacitive current exceeds the fault threshold value when grounding; through the measurement of the ground voltage change measurement module to measure the discharge current of the wire and the fuse to the ground, the line-to-ground voltage change is calculated.

As shown in Figure 3, the fault current judgment module includes a signal amplification circuit 131 with an induced current, and the output terminals of the signal amplification circuit 131 are respectively connected with a DC detection circuit 132 and an AC detection circuit 133, and the DC detection circuit 132 The output end of the AC detection circuit 133 is connected to the DC component judgment circuit 134, and the transient capacitance current threshold judgment output is realized by the detection circuit 132 and the DC component judgment circuit 134; and the high-frequency signal high-current amplitude judgment circuit 136, wherein the AC detection circuit 133 and the power-frequency signal high-current amplitude judgment circuit 135 realize the judgment output of the power-frequency high-current sudden change threshold, and the AC detection circuit 133 and the high-frequency signal high-current The amplitude judging circuit 136 realizes the judgment output of the high frequency and large current sudden change threshold. The specific functions of each circuit are as follows:

1) Signal amplifying current 131: amplify the induced current obtained through the change of the electromagnetic field around the wire through a linear amplifier, and separate two channels for judgment by different methods;

2) DC detection circuit 132: through the waveform matching circuit, obtain the transient capacitive current signal component in the branch 1, and filter out power frequency, high frequency and other signal components;

3) DC component judging circuit 134: compare the amplitude of the obtained transient current current signal component, and judge whether the signal is a fault current signal;

4) AC detection circuit 133: through the waveform matching circuit, obtain the power frequency signal component and the high frequency signal component in the branch 2;

5) Power frequency signal judgment circuit 135: compare the amplitude of the obtained power frequency signal components, and judge whether the signal is a fault current signal;

6) High-frequency signal judging circuit 136: Performs amplitude comparison on the obtained high-frequency signal component, and judges whether the signal is a fault current signal.

As shown in Figure 4, described ground voltage variation measurement module comprises the capacitance circuit 137 that is connected with high-voltage wire, is used to measure the discharge current measurement circuit 138 of capacitance current size of capacitance circuit, and the average value sampling that is connected with discharge current measurement circuit 138 The circuit 139 obtains the voltage change value of the high-voltage wire to the ground through the ground voltage change measurement module. The specific functions of each circuit are as follows:

1) Capacitive circuit 137: the air medium between the high-voltage wire and the ground has a weak discharge current when the high-voltage wire and the ground have voltage, and the capacitor circuit is used to convert the alternating weak current into a capacitor discharge current, which is convenient for measurement;

2) Discharge current measurement circuit 138: measure the capacitive current through a high-precision current measurement circuit;

3) Average value sampling circuit 139: obtain the average amplitude of the capacitive current within the set period, and when the average amplitude change exceeds the set threshold, the first main processing unit calculates the change of the average amplitude of the capacitive current by the first main processing unit. The variation of ground voltage is used as one of the basis for fault judgment.

The terminal device described in this embodiment uses analog circuits to detect changes in power line current and voltage, and automatically recognizes fault currents and corresponding voltage changes, thereby triggering the first main processor 11 to perform fault analysis and judgment.

The communication terminal 2 includes a second main processing unit 21, a second local communication unit 22 connected to the second main processing unit 21, a remote communication unit 23, a second display unit 24, a second data interface unit 25, a second A power supply unit 26 and a second data storage unit 27 . The functions of each unit are as follows:

1) The second main processing unit 21: through the second local communication unit 22, receive the fault information, measurement data, fuse action and opening and closing status uploaded by the detection terminal 1; through the remote communication unit 23, transmit the data to the system remotely The master station 3; the second display unit 24, which displays the working status of the communication terminal 2;

2) The second local communication unit 22: can support short-distance wireless communication, optical fiber communication, etc., and establish a data communication channel between the communication terminal 2 and the detection terminal 1;

3) Remote communication unit 23: It can support SMS, GPRS, 3G, optical fiber communication, etc., and realize two-way communication with the system master station;

4) The second data interface unit 25: has interfaces such as Ethernet and RS232/485, and supports functions such as local maintenance of equipment, data access of external equipment, and local data output;

5) The second power supply unit 26: use solar power, battery or external mains to obtain electric energy, and provide power for each functional unit;

6) The second data storage unit 27: store various data received from the detection terminal, such as when the remote communication is interrupted, it can support resuming transmission or retransmission.

The fuse online monitoring system described in this embodiment can realize the real-time online detection of the operating status and parameters of the fuse itself, the line where it is located, and the load. It has the characteristics of simple structure, low cost, convenient installation, and flexible communication networking. It helps to improve the level of condition-based maintenance of equipment, and can also effectively shorten the time for fault finding and improve the reliability of power supply by obtaining the fault location in time.

The above-mentioned embodiments and drawings do not limit the form and style of the product of the present invention, and any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims (9)

1. a kind of fuse on-line monitoring system, it is characterised in that：It is described including detection terminal, communication terminal and system main website Detection terminal includes the first Main Processor Unit, electromagnetic field inducing unit, and the Current Voltage being connected with the first Main Processor Unit Detection unit, positional information collecting unit, the first area communication units and the first display unit, the electromagnetic field inducing unit with Current Voltage detection unit is connected；The communication terminal includes the second Main Processor Unit, and is connected with the second Main Processor Unit The second area communication units, telecommunication unit, the second display unit；The detection terminal is fixedly mounted on each of fuse On individual fusion tube；The fuse parameters that the detection terminal will be detected locally are led to by the first area communication units, second Letter unit is sent to the Main Processor Unit of communication terminal second, and second Main Processor Unit is sent to by telecommunication unit again System main website.

2. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：First Main Processor Unit, Second Main Processor Unit is using microprocessor control.

3. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：The electromagnetic field inducing unit is adopted With magnetic sensors, the positional information collecting unit uses magnetoresistive transducer.

4. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：The Current Voltage detection unit Including fault current judging module and voltage-to-ground measure of the change module.

5. a kind of fuse on-line monitoring system as claimed in claim 4, it is characterised in that：The fault current judging module Including the signal amplification circuit being connected with induced-current, the output end of the signal amplification circuit connects direct current detecting circuit respectively With exchange detecting circuit, the output end connection DC component decision circuit of the direct current detecting circuit, by direct current detecting circuit Realize that transient state capacitance current thresholding judges output with DC component decision circuit；The output end of the exchange detecting circuit connects respectively Connect power frequency component high current amplitude decision circuit and high-frequency signal high current amplitude decision circuit, wherein, exchange detecting circuit and Power frequency component high current amplitude decision circuit realizes power frequency heavy-current mutation threshold judgement output, exchange detecting circuit and high frequency letter Number high current amplitude decision circuit realizes the mutation threshold judgement output of high frequency high current.

6. a kind of fuse on-line monitoring system as claimed in claim 4, it is characterised in that：The voltage-to-ground measure of the change Module includes the condenser network being connected with high-voltage conducting wires, and the discharge current for measuring condenser network capacitance current size measures electricity Road, and the average sample circuit being connected with discharge current measuring circuit, high pressure is obtained by voltage-to-ground measure of the change module Wire voltage-to-ground changing value.

7. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：First area communication units Radio communication or fiber optic communication are used with the second area communication units.

8. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：The telecommunication unit is used Short message, GPRS, 3G or fiber optic communication.

9. a kind of fuse on-line monitoring system as claimed in claim 1, it is characterised in that：The communication terminal also includes number According to interface unit, the data interface unit is using one or more in Ethernet, RS232, RS485.