CN1250978C - Passive earth detecting method and device for main circuit of ac-dc electric locomotive - Google Patents
Passive earth detecting method and device for main circuit of ac-dc electric locomotive Download PDFInfo
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- CN1250978C CN1250978C CN 200410009602 CN200410009602A CN1250978C CN 1250978 C CN1250978 C CN 1250978C CN 200410009602 CN200410009602 CN 200410009602 CN 200410009602 A CN200410009602 A CN 200410009602A CN 1250978 C CN1250978 C CN 1250978C
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02T90/10—Technologies relating to charging of electric vehicles
- Y02T90/16—Information or communication technologies improving the operation of electric vehicles
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Abstract
The present invention relates to a method and a device for detecting passive ground detecting which are applied to a main circuit of an AC/DC electric locomotive. The device comprises a main controller, a voltage collecting unit, a warning unit and an upper machine, wherein the voltage collecting unit is connected with divider resistors R1, R1', R2, and R2' between a DC positive bus and a DC negative bus, the R1' and the R2' are respectively connected in parallel with a isolated operational amplifier, and voltage to ground V1, V2 of the positive bus and the negative bus of the main circuit is divided by the resistors, then enters the isolated operational amplifier, and is inputted into the main controller through an A/D port of the main controller as input data of fault judgment. The passive detecting method utilizes the characteristics that a silicon controlled rectifier generates voltage spikes during conducting every time when the locomotive runs with loading to judge working conditions of the main circuit; whether a DC side of the main circuit has a ground fault is judged by computing voltage ratio changes of the positive bus and the negative bus; fast Fourier transform is carried out on the sampled voltage of the positive bus and the negative bus to compute the values of 50Hz of voltage components, the value of the voltage components is compared with corresponding warning valve values which are set in different working conditions, and thus, whether an AC ground fault of the main circuit occurs is judged.
Description
Technical field
The present invention relates to a kind of ground detecting method that is used for main circuit of electric locomotive, especially relate to a kind of ground detecting method that is used for AC-DC electric locomotive main circuit.
Background technology
The main circuit of electric locomotive of AC-DC electric locomotive is by traction motor and be attached thereto the electrical equipment and the lead that connect and form, main circuit is the high-power drive road of high voltage in the electric locomotive, big electric current, power transmission by main circuit, the electric energy of electric substation can be transformed into and be applicable to the needed tractive force of locomotive traction, be the electric locomotive most important component.Main circuit earth fault mainly is because the damage in insulation of electrical equipment or lead causes, be " dead ground connection " with steel structure of car body directly contacts, the nuditing wire part by air to the steel construction discharge or by the insulant surface to steel construction creepage be " swinging earth ".Earth point occurs will causing short trouble and burning apparatus or lead more than 2, so sensitive ground detection device reliably must be installed on main circuit of electric locomotive.
Existing AC-DC electric locomotive main circuit ground detection device is active ground connection detection mode; this detection mode need be injected the signal of 110V control circuit; when earth fault appears in certain node; the signal of 110V can constitute the loop by resistance and relay; the detection relay has big electric current and flows through, and makes relay tripping protection.
There are some shortcomings in active ground detecting method and device: at first, this method need be received 110V control circuit voltage negative pole on the locomotive shell, promptly with the 25KV electrical network altogether, control circuit is directly scurried in the interference that electric connection will cause electrical network and main circuit thyristor conducting shutoff to bring, on the design locomotive, have to increase extra filtering measures during other control panel and reduce interference, especially under the increasing situation of control panel on the locomotive, the interference that is caused altogether by control circuit and main circuit has become the bottleneck that improves the control panel reliability; Secondly, during locomotive operation vibrations bigger, detect relay contact mistake tripping can take place, false alarm takes place easily; At last, checkout equipment is more, has comprised absorption circuit of grounding relay, current-limiting resistance, relay etc., and workload is big during maintenance.
Some other earth-fault detecting method as the detection methods to the additional AC test signals of straight-flow system injection that adopt in the electric system, can bring certain influence to straight-flow system itself more, is difficult to electric locomotive.
Summary of the invention
The technical problem to be solved in the present invention:
Overcoming existing active ground detecting method needs additional signal to inject, control circuit 110V signal and ground can not be kept apart, the electromagnetic interference (EMI) of control circuit is bigger, can not accurately judge shortcomings such as earth fault particular location, a kind of Intelligent Passive ground detecting method and device that is used for AC-DC electric locomotive main circuit is provided, effectively solves the difficult problem of main circuit Earth Fault Detection.
The technical scheme that the present invention takes:
The Intelligent Passive ground detection device that is used for AC-DC electric locomotive main circuit, master controller are connected with voltage acquisition unit, alarm unit and host computer respectively.Voltage acquisition unit is gathered main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2And send master controller to, as the input data of fault diagnosis; Alarm unit control fault pilot lamp and main circuit breaker of railway engine are realized fault-signal output; Failure message when host computer is used for noting operation; Master controller is realized the algorithm routine of detection method, the work of management voltage acquisition unit, alarm unit, host computer.
Passive ground detection device is installed in the DC side after each the traction winding rectification of AC-DC electric locomotive main circuit, and interface circuit is voltage acquisition unit, as shown in Figure 2.Between the direct current positive and negative busbar, insert and detect divider resistance R
1, R
1', R
2', R
2, choose resistance R
1=R
2, R
1'=R
2', R
1' and R
2' between receive on the locomotive shell, promptly be communicated with the earth.R
1', R
2' in parallel with an isolation amplifier respectively.Main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Through behind the electric resistance partial pressure, enter and isolate the A/D mouth input master controller that amplifier is passed through master controller again, as the input data of fault judgement.
The passive ground detecting method that the present invention adopts may further comprise the steps:
1, judge the locomotive operating mode:
Main circuit of electric locomotive exists unloaded and band carries two kinds of operating modes, should be distinguished when detecting main circuit AC side earth fault, when utilizing the locomotive run with load, the present invention can produce the characteristics of due to voltage spikes during the each conducting of controllable silicon, by to main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Carry out quick sampling, judge whether to exist the periodic due to voltage spikes of 50Hz, if any, then main circuit is operated in band and carries operating mode, the interchange alarming threshold value when using band to carry; As do not have, then be operated in idle condition, the interchange alarming threshold value when using zero load, determining with concrete conditions such as vehicles of alarming threshold value is relevant.
2, judge the main circuit DC ground fault:
To V
1, V
2Carry out continuous quick sampling, definition V
0=V
1+ V
2, calculate V respectively by master controller
0, and V
1And V
2Mean value separately
,
,
When master controller is judged inequality
Set up, judge that then earth fault has taken place direct current negative pole "-".When master controller is judged inequality
Set up, judge that then earth fault has taken place direct-flow positive pole "+".
3, judge main circuit AC side earth fault:
Ground connection for the main circuit AC side is judged, the present invention proposes the detection method that the corresponding frequencies that adopts fast fourier transform FFT to calculate sampled voltage judges whether to exist earth fault.The main circuit direct current positive bus voltage V over the ground that has sampled when utilizing DC side ground connection to judge
1With direct current negative busbar voltage V over the ground
2, by the algorithm routine of master controller to magnitude of voltage V
1, V
2Carry out fast fourier transform, calculate V
1And V
2The 50Hz component of voltage.
Because during the main circuit operate as normal is single-phase bridge rectification, the voltage after the rectification on the dc bus should be the steamed bun ripple of 100Hz, promptly samples the voltage V of master controller
1And V
2The main frequency signal be 100Hz, the amplitude of other frequency signal is very little.And when main circuit AC side generation earth fault, main circuit is equivalent to have one road thyristor by short circuit, and then equivalent electrical circuit becomes single phase half wave rectification by single-phase bridge rectification, so sampling obtains voltage V
1And V
2Main component of voltage become 50Hz, all there is obvious increase in the 50Hz component of two-way voltage, can calculate the 50Hz component of voltage of two-way sampled voltage like this by master controller,, then can judge to have main circuit AC side earth fault if the 50Hz component of two-way voltage all surpasses alarming threshold value.
4. report to the police:
When master controller has been judged earth fault, send alerting signal to alarm unit, alarm unit is started working, and by control fault pilot lamp and main circuit breaker of railway engine, realizes fault-signal output.Failure message sends to host computer by serial communication, sets up fault file.
Beneficial effect of the present invention:
Passive ground detecting method that the present invention proposes and device do not need additional signal to inject, and control circuit and ground can be kept apart, and effectively reduce the electromagnetic interference (EMI) of control circuit; There is not the detection relay, can avoid owing to shake the false alarm that produces, checkout equipment is few, and maintenance workload is less ' to have adopted Digital Signal Processing, effectively avoid the big and influence of distributed capacitance over the ground of dc voltage ripple, solved the difficult problem of main circuit Earth Fault Detection.This detection method can also be told the Position Approximate of earth fault, as AC side, direct current positive bus or direct current negative busbar etc., can further improve the electric automatization level of electric locomotive.
Description of drawings
Fig. 1 is passive ground detection device structured flowchart.
Fig. 2 is the voltage acquisition unit of passive ground detection device.
Fig. 3 is passive ground detecting method program flow diagram.
Fig. 4 is in the actual service testing, positive and negative busbar voltage-to-ground waveform during the main circuit operate as normal, and waveform 1 is the positive bus-bar voltage-to-ground, waveform 2 is the negative busbar voltage-to-ground.
Fig. 5 is in the actual service testing, positive and negative busbar voltage-to-ground waveform during main circuit direct current positive bus ground connection, and waveform 1 is the positive bus-bar voltage-to-ground, waveform 2 is the negative busbar voltage-to-ground.
Fig. 6 is in the actual service testing, positive and negative busbar voltage-to-ground waveform during main circuit AC side ground connection, and waveform 1 is the positive bus-bar voltage-to-ground, waveform 2 is the negative busbar voltage-to-ground.
Fig. 7 is in the actual service testing, the due to voltage spikes waveform that band produces when carrying controllable silicon conducting that records under the operating mode, and oscillograph is made as ordinate 100/ lattice, horizontal ordinate 500s/ lattice.
Embodiment
Passive ground detection device is installed in the DC side after each traction winding rectification of main circuit, by detecting main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Judge earth fault.Interface circuit is a voltage acquisition unit shown in Figure 2, the detection divider resistance equal and opposite in direction that on the direct current positive and negative busbar, inserts, and the actual resistance value of choosing is R
1=R
2=360K Ω, R
1'=R
2'=15 Ω, resistance can suitably be adjusted R according to the variation of various vehicle main circuit magnitudes of voltage
1' and R
2' between receive on the locomotive shell, promptly be communicated with ground.Main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Through behind the electric resistance partial pressure, enter the isolation amplifier, that isolate that amplifier uses is the 7800A of Agilent company, can the electrical isolation main circuit and the control section of system, and voltage signal amplified.Positive and negative two-way voltage signal V
1, V
2Through behind the 7800A, the A/D mouth by master controller is sampled into master controller, as the input data of fault judgement.What master controller used is the l6 8-digit microcontroller of MOTORQLA company, and model is MC9S12A64CPV, and the microcontroller that function is close also can use with it.Master controller links to each other with voltage acquisition unit, alarm unit, host computer respectively and manages their work, carries out real-time fault diagnosis computing, Figure 3 shows that master controller realizes passive ground connection trace routine algorithm flow chart.
Main circuit of electric locomotive exists unloaded and band carries two kinds of operating modes, the interchange alarming threshold value difference of finding these two kinds of operating modes in actual detected is bigger, need set up different alarming threshold values, this just need at first judge the operating mode of main circuit of electric locomotive, and judging that by the signal that driver's handle provides main circuit is operated in zero load or band carries relatively difficulty of state, the present invention proposes to utilize the waveform of sampled voltage to judge.Controllable silicon needed conducting open when the main circuit band carried work, and can on dc voltage, produce a spike during the each conducting of controllable silicon, detect in the circulation earlier to 4 power frequency periods of voltage quick sampling at each, be 40ms, judged whether that by master controller periodically spike exists, if any, then main circuit is operated in band and carries operating mode, the interchange alarming threshold value when using band to carry; As do not have, then be operated in idle condition, the interchange alarming threshold value when using zero load.
Carry out the judgement of main circuit DC side ground connection, need V
1, V
2Several power frequency periods of continuous sampling have been gathered the magnitude of voltage of 256 points with the sample frequency of 1.28K in the real system, the sampling time is 200ms altogether, calculates V respectively by master controller
0, and V
1And V
2Mean value separately
,
,
, V wherein
0=V
1+ V
2When ground connection takes place in direct current positive bus, because resistance R
1' and R
1By short circuit, the busbar voltage of main circuit all is added in resistance R
2' and R
2On, i.e. the voltage V that sampling is returned
1Approximate 0, voltage V
2Approximate V
0In like manner, when ground connection takes place in the direct current negative busbar, resistance R
2' and R
2By short circuit, the busbar voltage of main circuit all is added in resistance R
1' and R
1On, the voltage V that sampling is returned
2Approximate 0, voltage V
1Should approximate V
0Work as master controller like this and determine inequality
Set up, can judge that then earth fault has taken place direct current negative pole "-".If inequality
Set up, can judge that then earth fault has taken place direct-flow positive pole "+".
For judging of main circuit AC side, the present invention proposes the detection method that the corresponding frequencies that adopts fast fourier transform FFT to calculate sampled voltage judges whether to exist earth fault by ground.The magnitude of voltage of 256 points of having sampled when utilizing DC side ground connection to judge, by the algorithm routine of master controller to main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Carry out fast fourier transform, calculate V
1And V
2The 50Hz component of voltage.Because during the main circuit operate as normal is single-phase bridge rectification, the voltage after the rectification on the dc bus should be the steamed bun ripple of 100Hz, promptly samples the voltage V of master controller
1And V
2The main frequency signal be 100Hz, the amplitude of other frequency is very little.And when main circuit AC side generation earth fault, main circuit is equivalent to have one road thyristor by short circuit, and equivalent electrical circuit becomes single phase half wave rectification by single-phase bridge rectification, so sample voltage V
1And V
2Main component of voltage become 50Hz.Can judge whether to exist main circuit AC side earth fault by the variation that master controller calculates the 50Hz component of voltage of two-way sampled voltage like this, then the earth fault of main circuit AC side has appearred in decidable when the 50Hz of two-way voltage component all surpasses the interchange alarming threshold value of determining.
When master controller has been judged earth fault, send alerting signal to alarm unit, alarm unit comprises three malfunction indicator lamp, indicating the earth fault of AC side, direct current positive bus and direct current negative busbar respectively, is green light during operate as normal, when earth fault occurs, corresponding malfunction indicator lamp becomes shiny red, and the alerting signal that provides one road 110V enters the logic control element LCU of locomotive, is used for jumping main disconnected, and locomotive is stopped.Failure message can pass to host computer by serial communication, sets up fault file.
Below in conjunction with accompanying drawing 4, Fig. 5, Fig. 6 and Fig. 7, provide the actual measurement waveform of the present invention when the enterprising luggage car of electric locomotive is tested.
DC side positive and negative busbar voltage waveform over the ground when Figure 4 shows that the main circuit operate as normal, wherein waveform 1 is the positive bus-bar voltage-to-ground, waveform 2 is the negative busbar voltage-to-ground.Be the 100Hz steamed bun ripple that single-phase bridge rectification comes out as can be seen, owing to there is the bus influence of distributed capacitance over the ground, positive and negative busbar voltage-to-ground waveform is very not symmetrical.
Figure 5 shows that direct current positive bus ground connection to positive and negative busbar voltage-to-ground waveform, waveform 1 is the positive bus-bar voltage-to-ground, and waveform 2 is the negative busbar voltage-to-ground.Can see significantly that positive bus-bar voltage has been 0 substantially, press the standard of the judgement DC side earth fault of the present invention's proposition, can report to the police exactly.
Positive and negative busbar voltage-to-ground waveform when Figure 6 shows that AC side ground connection, waveform 1 is the positive bus-bar voltage-to-ground, waveform 2 is the negative busbar voltage-to-ground.Can see significantly that the voltage waveform frequency is become based on 50Hz by original 100Hz, the judgement of using the present invention's proposition exchanges the standard and the method for side joint fault, can report to the police exactly.
Figure 7 shows that the due to voltage spikes waveform that produces when being with a controllable silicon conducting of carrying fault under the operating mode, the due to voltage spikes ascensional range is about 100V as can be seen, and the rise time is about 100us.Adopt in test the magnitude of voltage of 1000 points with the sampling period of 40us, can tell the periodic voltage spike of being with when carrying exactly, it is very reliable to judge that band carries with idle condition.
In whole service testing, all possible earth fault has all been carried out earth test, the errorless phenomenon that reports an error takes place, and it is reliable to report to the police.
Claims (1)
1. passive ground detecting method that is used for AC-DC electric locomotive main circuit, the passive ground detection device that is used for AC-DC electric locomotive main circuit, this device comprises master controller, voltage acquisition unit, alarm unit, host computer, the method includes the steps of: judge that main circuit is operated in band and carries still idle condition, determine to judge the alarming threshold value of main circuit AC side ground connection; Judge whether to exist main circuit DC side earth fault; Judge whether to exist main circuit AC side earth fault, it is characterized in that,
1. to main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Carry out quick sampling, when judging the main circuit operating mode, can produce the characteristics of due to voltage spikes when utilizing the locomotive run with load during the each conducting of controllable silicon, judge whether to exist 50Hz periodic voltage spike: if any 50Hz periodic voltage spike, then main circuit is operated in band and carries operating mode, the interchange alarming threshold value when using band to carry; As do not have 50Hz periodic voltage spike, then be operated in idle condition, the interchange alarming threshold value when using zero load;
2. main circuit direct current positive bus voltage V over the ground
1With direct current negative busbar voltage V over the ground
2Sum is defined as V
0, i.e. V
0=V
1+ V
2, calculate V respectively by master controller
0, and V
1And V
2Mean value separately
When master controller is judged inequality
Set up, judge that then earth fault has taken place direct current negative pole "-", when master controller is judged inequality
Set up, judge that then earth fault has taken place direct-flow positive pole "+";
When 3. judging main circuit AC side earth fault, utilize the main circuit direct current positive bus voltage-to-ground V that has sampled
1With direct current negative busbar voltage-to-ground V
2, to V
1, V
2Carry out fast fourier transform, calculate V
1And V
2The size of 50Hz component of voltage, according to the locomotive operation operating mode of 1. judging, compare with the corresponding alarming threshold value that configures, if the 50Hz component of two-way voltage all surpasses alarming threshold value, then can judge to have main circuit AC side earth fault, alarming threshold value is set according to the vehicle concrete condition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410009602 CN1250978C (en) | 2004-09-24 | 2004-09-24 | Passive earth detecting method and device for main circuit of ac-dc electric locomotive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410009602 CN1250978C (en) | 2004-09-24 | 2004-09-24 | Passive earth detecting method and device for main circuit of ac-dc electric locomotive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1598606A CN1598606A (en) | 2005-03-23 |
| CN1250978C true CN1250978C (en) | 2006-04-12 |
Family
ID=34662543
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410009602 Expired - Fee Related CN1250978C (en) | 2004-09-24 | 2004-09-24 | Passive earth detecting method and device for main circuit of ac-dc electric locomotive |
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|---|---|
| CN (1) | CN1250978C (en) |
Cited By (1)
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2004
- 2004-09-24 CN CN 200410009602 patent/CN1250978C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102565648A (en) * | 2012-02-17 | 2012-07-11 | 青岛四方车辆研究所有限公司 | DC600V main line on-line insulation monitoring device |
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|---|---|
| CN1598606A (en) | 2005-03-23 |
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Assignee: INNOVATION TECHNOLOGY CENTER OF BEIJING JIAOTONG UNIVERSITY Assignor: Beijing Jiaotong University Contract record no.: 2011110000044 Denomination of invention: Passive earth detecting method and device for main circuit of ac-dc electric locomotive Granted publication date: 20060412 License type: Exclusive License Open date: 20050323 Record date: 20110613 |
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Granted publication date: 20060412 Termination date: 20160924 |