CN101719662B - Fault line selection device for distribution line of small-current grounding system - Google Patents
Fault line selection device for distribution line of small-current grounding system Download PDFInfo
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- CN101719662B CN101719662B CN2009102369734A CN200910236973A CN101719662B CN 101719662 B CN101719662 B CN 101719662B CN 2009102369734 A CN2009102369734 A CN 2009102369734A CN 200910236973 A CN200910236973 A CN 200910236973A CN 101719662 B CN101719662 B CN 101719662B
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Abstract
The invention provides a fault line selection device for a distribution line of a small-current grounding system. The fault line selection device comprises a converter, a data collector, a central processing unit and a communication interface device, wherein the converter is connected with a zero-sequence current transformer and used for converting large current from the zero-sequence current transformer into analog voltage signals having predetermined values and outputting the analog voltage signals to the data collector; the data collector is used for converting the analog voltage signals from the converter into digital signals, storing the digital signals in a data memory and outputting the digital signals to the central processing unit after a fault occurs; the central processing unit is used for processing the digital signals from the data collector, judging the fault line and outputting judgment results to the communication interface device; and the communication interface device is used for outputting the judgment results.
Description
Technical field
The present invention relates to electric power system fault route selection technical field, relate in particular to the fault line selection device of distribution line of small-current grounding system.
Background technology
It is a difficult problem of relay protection of power system theory and technology that small current system single-phase earth fault detects always.During small current system generation single phase ground fault, the power frequency fault current is a circuit direct-to-ground capacitance Leakage Current, and current value is little, and fault signature is not obvious.And small current system is when normally moving, and unsymmetrical current is relatively large.Therefore, existing fault-line selecting method based on power current is difficult to accurately distinguish fault current and unsymmetrical current, correctly route selection.But on the one hand, the single-phase earthing transient process has comprised abundant fault message, and the transient state travelling wave electric current can correctly reflect fault time, faulty line and abort situation.On the other hand, the unsymmetrical current when system normally moves is a steady-state current, and it can separate the natural region with fault transient.So, utilize the route selection research of transient state travelling wave electric current to open up a new way for carrying out the small current system single-phase earth fault detection.
Existing capable ripple line selection apparatus receives the travelling wave signal from current transformer; Monitor the current traveling wave on each loop line road; According to the current traveling wave of faulty line greater than non-fault line; Opposite polarity principle is selected faulty line, and judged result is uploaded to the control room through signal cable or point-to-point communication protocol.In addition, for interference in the compartment system and fault, existing capable ripple line selection apparatus also utilizes signal cable to introduce the open delta side voltage of the voltage transformer on the bus.Conventional device can satisfy the application requirements of traditional transformer station; But development along with transformer station's technology; The appearance of digital transformer substation and popularization; Communication in the transformer station adopts public serial ports network service to replace existing privately owned point-to-point communication, and existing capable ripple line selection apparatus can not satisfy the requirement of digital transformer substation.
Summary of the invention
The objective of the invention is to propose a kind of capable ripple line selection apparatus, solve the failure line selection problem of small current neutral grounding system, and satisfy the communicating requirement of digital transformer substation based on digital transformer substation.The present invention adopts the transient state travelling wave electric current that produces after the fault to select faulty line, and maximum based on the capable wave amplitude of faulty line, polarity and non-fault line contrary principles realize.The present invention has realized a kind of communication of the IEC61850 of meeting standard, satisfies the requirement of digital transformer substation automated system.
The invention provides a kind of fault line selection device of distribution line of small-current grounding system; Comprise: converter; Be connected with zero sequence current mutual inductor; To change the analog voltage signal of predetermined value from the big electrorheological of said zero sequence current mutual inductor into, and said analog voltage signal will be exported to data acquisition unit; Data acquisition unit will change into digital signal from the said analog voltage signal of said converter, and said digital signal will be stored in the data storage, after fault takes place, said digital signal exported to central processing unit; Said central processing unit is used for the said digital signal from said data acquisition unit is handled, and carries out faulty line and judges, and judged result is exported to communication interface, by said communication interface output; Said communication interface is used to export said judged result.
In technique scheme, preferably, said central processing unit adopts the wavelet transformation analysis travelling wave signal, extracts travelling wave signal amplitude Characteristics and polarity, and will go the wave amplitude maximum, and the circuit that polarity and All other routes are opposite is chosen as faulty line.
In technique scheme, preferably, said communication interface converts the judged result that receives to meet the IEC61850 standard route selection result, and is uploaded to electric substation automation system through network.
In technique scheme, preferably, said converter is connected with 24 zero sequence current mutual inductors.
In technique scheme, preferably, said data acquisition unit comprises hardware-initiated unit of earth fault and data acquisition unit.The hardware-initiated unit of said earth fault is used for comparison input current and threshold value, if the component of the preset frequency in the said input current reaches said threshold value, then output low level in the judgement system ground connection has been taken place.Said data acquisition unit comprises: multicircuit switch, high-speed A/D converter and data storage.
In technique scheme; Preferably; Said communication interface is monitored the serial data that said central processing unit sends; After handling said serial data, search and whether break down and faulty line, and treated serial data is sent towards transformer substation case object message and manufacturing message specification message form through general.
In technique scheme; Preferably, said communication interface listens for network packet, when listen to send out to the SNTP of said communication interface to the time during message; Start-up system to the time module; The system that carries out said communication interface to the time, and through serial ports will to the time data send to said central processing unit, thereby realize said fault line selection device to the time function.
In technique scheme; Preferably, said communication interface adopts winpcap accesses network bottom, catches initial data; Resolve general towards transformer substation case object message; Realize information communication, adopt socket to realize the network data transmission, the manufacturing message specification message of accomplishing based on TCP/IP sends.
In technique scheme, preferably, said predetermined value is 5 volts.
Preferably, said central processing unit combines voltage signal to judge whether system fault has taken place, if fault has taken place, the result is exported to communication interface as a result.
Preferably, said central processing unit carries out Filtering Processing and wavelet conversion to the transient current from said data acquisition unit to be handled, the failure judgement circuit, and the result exported to said communication interface.And failure logging uploaded distant place control system.
Preferably, further comprise power supply, be used to said converter, said data acquisition unit, said central processing unit, the power supply of said communication interface.
Preferably, the said data acquisition unit image data constantly that circulates behind the hardware-initiated unit starting of said earth fault, reads 128 sampled points of the capable wave datum of zero-sequence current on every loop line road from circulating memory.
The present invention also provides a kind of distribution line of small-current grounding system fault line selection device, it is characterized in that this device comprises:
Converter plate, the secondary side of it and zero sequence current mutual inductor links, and the big electrorheological that will come from zero sequence current mutual inductor changes 5 volts voltage signal into, and this voltage signal is exported to data acquisition board;
Data acquisition board: it converts the analog voltage signal from converter plate to digital signal, and is stored in the data storage, and fault is exported to the central processing unit plate after taking place; Institute's data acquisition board of carrying is gathered current traveling wave;
The central processing unit plate: it handles the data from data acquisition board, carries out faulty line and judges, and judged result is exported to communication interface board; Institute's central processing unit plate of carrying adopts the wavelet transformation analysis travelling wave signal, extracts travelling wave signal amplitude Characteristics and polarity, and will go the wave amplitude maximum, and the circuit that polarity and All other routes are opposite is chosen as faulty line;
Communication interface board: this plate receives the route selection result from the central processing unit plate, is converted into the data that meet the IEC61850 standard, through network interface the route selection result is uploaded to electric substation automation system;
Power panel: for package unit provides working power.
Adopt technique scheme, can realize following technique effect:
1, can accurately select faulty line, no matter be metallicity fault or transient fault.
2, can select faulty line in real time, begin from earth fault, be selected out to faulty line, the time is no more than 50 milliseconds.
3, can monitor nearly 24 times distribution lines simultaneously.
4, can be applied to various earth neutral systems: isolated neutral system; The neutral by arc extinction coil grounding system; Neutral point is through the high resistance ground system; Hinder grounding system in the neutral point warp; Neutral point is through low-impedance earthed system system and solidly earthed neutral system.
5, can satisfy the requirement of the electric substation automation system of the digital transformer substation that meets the IEC61850 standard.
Description of drawings
Fig. 1 shows the block diagram of the fault line selection device of distribution line of small-current grounding system according to an embodiment of the invention;
Fig. 2 shows the structure chart of the fault line selection device of distribution line of small-current grounding system according to an embodiment of the invention;
The block diagram of the data acquisition unit that Fig. 3 is adopted in showing according to one embodiment of present invention; And
The block diagram of the central processing unit that Fig. 4 is adopted in showing according to one embodiment of present invention.
Embodiment
To combine accompanying drawing below, specifically describe the present invention.
Fig. 1 shows the block diagram of distribution line failure line selection apparatus according to an embodiment of the invention.
The distribution line failure line selection apparatus 100 that is used for distribution line of small-current grounding system comprises converter 102, data acquisition unit 104, central processing unit 106 and communication interface 108.Converter 102 is connected with zero sequence current mutual inductor 1022, will change analog voltage signal into from the big electrorheological of said zero sequence current mutual inductor 1022, and said analog voltage signal is exported to data acquisition unit 104.Data acquisition unit 104 is used for converting the said analog voltage signal from said converter to digital voltage signal, and is stored in the data storage, after fault takes place, exports to central processing unit 106.Central processing unit 106 is used to handle the digital signal from said data acquisition unit 104, carries out faulty line and judges, and judged result is exported to communication interface 108, by communication interface 108 outputs.Communication interface 108 converts the judged result that receives to meet the IEC61850 standard route selection result, and is uploaded to electric substation automation system through network.Preferably, said predetermined value is 5 volts.Preferably, said central processing unit adopts the wavelet transformation analysis travelling wave signal, extracts travelling wave signal amplitude Characteristics and polarity, and will go the wave amplitude maximum, and the circuit that polarity and All other routes are opposite is chosen as faulty line.
Preferably, said central processing unit 106 combines voltage signal to judge whether system fault has taken place, if fault has taken place, the result is exported to communication interface 108.
Preferably, said data acquisition unit 104 comprises hardware-initiated unit 1042 of earth fault and data acquisition unit 1044.The hardware-initiated unit 1042 of said earth fault is used for comparison input current and threshold value, if the component of the preset frequency in the said input current reaches said threshold value, then output low level in the judgement system ground connection has been taken place.
Preferably, said data acquisition unit 1044 comprises multicircuit switch, high-speed A/D converter and data storage.
Preferably, 106 pairs of transient currents from said data acquisition unit of said central processing unit carry out Filtering Processing and wavelet conversion to be handled, the failure judgement circuit, and the result exported to said communication interface, failure logging is uploaded distant place control system.
Preferably, distribution line failure line selection apparatus 100 further comprises power supply 110, is used to said converter 102, said data acquisition unit 104, said central processing unit 106,108 power supplies of said communication interface.
Preferably, said data acquisition unit 104 image data constantly that circulates behind the hardware-initiated unit starting of said earth fault, reads 128 sampled points of the capable wave datum of zero-sequence current on every loop line road from circulating memory.
Preferably; Said communication interface is monitored the serial data that said central processing unit sends; After handling said serial data; Search and whether break down and faulty line, and treated serial data is sent towards transformer substation case object message and manufacturing message specification message form through general.
Preferably; Said communication interface listens for network packet; When listen to send out to the SNTP of said communication interface to the time during message, start-up system to the time module, the system that carries out said communication interface to the time; And through serial ports will to the time data send to said central processing unit, thereby realize said fault line selection device to the time function.
Preferably, said communication interface adopts winpcap accesses network bottom, catches initial data; Resolve general towards transformer substation case object message; Realize information communication, adopt socket to realize the network data transmission, the manufacturing message specification message of accomplishing based on TCP/IP sends.
Fig. 2 shows the structure chart of low-current ground fault line selection device according to an embodiment of the invention.
This low-current ground fault line selection device comprises (not shown) such as converter plate 202, data acquisition board 204, central processing unit plate 206, communication interface board 208, power panel 210 and power panel, buzzer, LCD screen, and is as shown in Figure 2.
The composition of each plank be connected as follows:
1. converter plate: its changes the big electrorheological that comes from zero sequence current mutual inductor into 5 volts analog voltage signal, can connect 24 zero sequence current mutual inductors at most, and this analog signal is offered the data acquisition board use.
2. data acquisition board: its converts all 5 volts of analog voltage signals that come from converter plate 21 to digital signal, and is stored in the data storage;
This plank is made up of two unit: hardware-initiated unit I of earth fault and data acquisition unit II, and like Fig. 3.
Wherein:
Hardware-initiated unit is an input current and a threshold value (definite value) relatively, if when the 3～10Khz transient state component in the input current reaches threshold value, and the comparator output low level.Ground connection has been taken place in the judgement system.
Data acquisition unit is made up of multicircuit switch, high-speed AD converter chip, data storage and correspondent control circuits.(analog-to-digital conversion) 24 tunnel current data are ceaselessly gathered in the high-speed AD converter circulation, and store in the data storage.
8 AD803 that the analog to digital converter chip adopts AD company to produce, the AD9300 that 8 variable connectors (each variable connector is connected four tunnel analog signal timesharing to 8 AD) adopt the said firm to produce.The loop-around data memory adopts dual port RAM.
3. central processing unit plate: its carries out Filtering Processing and wavelet transform process to the transient current travelling waves data that come from data acquisition board, the failure judgement circuit, and judged result exported to communication interface board, like Fig. 4.
This plate is made up of DSP chip and correspondent peripheral circuit.It mainly carries out wavelet transform process, obtains the capable wave amplitude of zero-sequence current and the polar character on 24 loop line roads, and will go the wave amplitude maximum, and the circuit that polarity and All other routes are opposite is chosen as faulty line.
Digital signal processor adopts the TMS320C32 DSP chip of TI company.Among Fig. 4, RAM is a data storage, and Flash is a program storage.16D, 32D represent 16, or 32 data/address bus or program bus respectively.
4. communication interface board: this plate receives the route selection result from the central processing unit plate, is converted into the data that meet the IEC61850 standard, through network interface fail result is uploaded to electric substation automation system.
In the present embodiment, this plate adopts and grinds auspicious industrial computer mainboard EC5-1714CLDNA.Central processing unit adopts Intel ULV Celeron-M super low-power consumption processor, dominant frequency 600MHz; Chipset adopts Intel 852GM+82801DB chipset; Internal memory adopts 2GB DDR internal memory.This plate and Central Processing Board communicate through serial ports, communicate through Ethernet with external equipment.This plate is monitored the serial data that Central Processing Board sends; After the deal with data; Search and whether break down and faulty line, and data are sent through GOOSE (Generic Object Oriented Substation Event is general in the transformer substation case object) message and MMS (Manufacturing Message Specification makes message specification) message form.Simultaneously; This plate listens for network packet; When listen to send out to own SNTP (Simple Network Time Protocol SNTP) to the time during message, start-up system to the time module, the system of completion communication interface board to the time; And through serial ports will to the time data be sent to Central Processing Board, thereby realize single unit system to the time function.
This plate adopts Winpcap accesses network bottom, catches raw data packets, resolves the GOOSE message, realizes information communication; Adopt Socket to realize the network data transmission, the MMS message of accomplishing based on TCP/IP (Transmission Control Protocol/Internet Protocol) sends.
5. power panel: the working power of package unit is provided, and power module adopts the Shanghai weighing apparatus to inspire confidence in the Switching Power Supply that Industrial Co., Ltd. produces.
The course of work according to technical scheme of the present invention is following:
The course of work of the present invention:
If one single-phase earthing has taken place circuit, this device will start work, and its course of work is following:
1. through being installed on the zero sequence current mutual inductor on every loop line road, the zero-sequence current on every loop line road (can reach the electric current on 24 loop line roads) is introduced into converter plate;
2. each converter electrorheological about 5 amperes (or 1 amperes) coming from current transformer changes 5 volts analog voltage signal into;
3. the start unit of data acquisition board front will detect the disturbance generation, hardware-initiated unit starting, output triggering level;
4. the data acquisition board continuous image data that circulates, hardware-initiated element reads 128 sampled points of the capable wave datum of zero-sequence current on every loop line road after starting from circulating memory;
5. these every time 128 capable wave datum that reach 24 times are carried out wavelet transformation;
6. the wavelet transformation characteristic value corresponding according to every loop line road relatively selected faulty line.
7. output to communication interface board to selection result (digital quantity, 0 representative is not a fault wire, 1 represents fault wire).
8. communication interface board converts the route selection result who receives into meet the IEC61850 standard data, is uploaded to electric substation automation system through network.
Adopt technique scheme, can realize following technique effect:
1, can accurately select faulty line, no matter be metallicity fault or transient fault.
2, can select faulty line in real time, begin from earth fault, be selected out to faulty line, the time is no more than 50 milliseconds.
3, can monitor nearly 24 times distribution lines simultaneously.
4, can be applied to various earth neutral systems: isolated neutral system; The neutral by arc extinction coil grounding system; Neutral point is through the high resistance ground system; Hinder grounding system in the neutral point warp; Neutral point is through low-impedance earthed system system and solidly earthed neutral system.
5, can satisfy the requirement of the electric substation automation system of the digital transformer substation that meets the IEC61850 standard.
The above is merely the preferred embodiments of the present invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1. the fault line selection device of a distribution line of small-current grounding system is characterized in that, comprising:
Converter is connected with zero sequence current mutual inductor, will change the analog voltage signal of predetermined value from the big electrorheological of said zero sequence current mutual inductor into, and said analog voltage signal is exported to data acquisition unit;
Data acquisition unit will change into digital signal from the said analog voltage signal of said converter, and said digital signal will be stored in the data storage, after fault takes place, said digital signal exported to central processing unit;
Said central processing unit is used for the said digital signal from said data acquisition unit is handled, and carries out faulty line and judges, and judged result is exported to communication interface, by said communication interface output; And
Said communication interface; Monitor the serial data that said central processing unit sends; After handling said serial data; Search and whether break down and faulty line, and treated serial data is sent towards transformer substation case object message and manufacturing message specification message form through general.
2. fault line selection device according to claim 1; It is characterized in that said central processing unit adopts the wavelet transformation analysis travelling wave signal, extract travelling wave signal amplitude Characteristics and polarity; And will go the wave amplitude maximum, the circuit that polarity and All other routes are opposite is chosen as faulty line.
3. fault line selection device according to claim 1 is characterized in that, said communication interface converts the judged result that receives to meet the IEC61850 standard route selection result, and is uploaded to electric substation automation system through network.
4. fault line selection device according to claim 1 is characterized in that, said converter is connected with 24 zero sequence current mutual inductors.
5. fault line selection device according to claim 1 is characterized in that, said data acquisition unit comprises hardware-initiated unit of earth fault and data acquisition unit.
6. fault line selection device according to claim 5; It is characterized in that the hardware-initiated unit of said earth fault is used for comparison input voltage and threshold value, if the component of the preset frequency in the said input voltage reaches said threshold value; Then ground connection has taken place in the judgement system in output low level.
7. fault line selection device according to claim 5 is characterized in that, said data acquisition unit comprises: multicircuit switch, high-speed A/D converter and data storage.
8. according to each described fault line selection device in the claim 1 to 7; It is characterized in that, said communication interface listens for network packet, when listen to send out to the SNTP of said communication interface to the time during message; Start-up system to the time module; The system that carries out said communication interface to the time, and through serial ports will to the time data send to said central processing unit, thereby realize said fault line selection device to the time function.
9. according to each described fault line selection device in the claim 1 to 7; It is characterized in that said communication interface adopts winpcap accesses network bottom, catches initial data; Resolve general towards transformer substation case object message; Realize information communication, adopt socket to realize the network data transmission, the manufacturing message specification message of accomplishing based on TCP/IP sends.
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| CN102280866A (en) * | 2011-02-10 | 2011-12-14 | 清华大学 | Traveling wave data acquisition and processing device |
| CN102221662A (en) * | 2011-03-29 | 2011-10-19 | 深圳市索图科技有限公司 | Small current grounding system single phase earth fault traveling wave line selection and distance measurement apparatus |
| CN102497029B (en) * | 2011-12-27 | 2014-03-26 | 思源电气股份有限公司 | Parallel medium resistance line selection apparatus based on IEC 61850 standard and method thereof |
| CN103278733B (en) * | 2013-05-30 | 2016-08-10 | 国家电网公司 | A kind of cable grounding remote monitoring method and Long-Range Surveillance System |
| CN104698369B (en) * | 2015-03-19 | 2017-10-17 | 西电通用电气自动化有限公司 | A kind of analog link hardware failure detection circuit and method |
| CN105158641A (en) * | 2015-09-18 | 2015-12-16 | 合肥海畅电气技术有限公司 | Small-current grounding line selection device line-outgoing system |
| CN108957248A (en) * | 2018-10-09 | 2018-12-07 | 国网河南省电力公司洛阳供电公司 | A kind of positioning of power distribution network primary fault and method for early warning |
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