CN110535104A - A kind of DC line fast protection method and system - Google Patents
A kind of DC line fast protection method and system Download PDFInfo
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- CN110535104A CN110535104A CN201910666471.9A CN201910666471A CN110535104A CN 110535104 A CN110535104 A CN 110535104A CN 201910666471 A CN201910666471 A CN 201910666471A CN 110535104 A CN110535104 A CN 110535104A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0092—Details of emergency protective circuit arrangements concerning the data processing means, e.g. expert systems, neural networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
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Abstract
The invention discloses a kind of DC line fast protection method and systems, comprising: when the corresponding dual-tree complex wavelet transform decomposition amount of the DC voltage of acquisition meets preset highly sensitive protection start-up criterion, starts highly sensitive protection；If current DC voltage, which meets preset exception, counts greatly locking criterion, latch-up protection；If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets preset failure criterion, protection act outlet.The present invention is after high sensitivity protection starting, if meeting the sub- criterion of bipolar failure, selects extremely sub- criterion, bipolar protection direct action without failure；If meeting failure selects extremely sub- criterion, after determining failure extremely, failure pole protection act；If being judged to abnormal big number, direct latch-up protection；The present invention can identify internal fault external fault fast and reliablely, have higher sensitivity to high resistance earthing fault, while being suitable for LCC and VSC system, meet various demands.
Description
Technical field
The present invention relates to technical field of relay protection, and more particularly, to a kind of DC line fast protection method
And system.
Background technique
The protection being equipped in DC transmission engineering at present mainly makees main protection with traveling-wave protection, under-voltage differential protection appts, with electricity
Stream differential protection makees back-up protection, and part engineering is also equipped with under-voltage protection.
In terms of traveling-wave protection, under-voltage differential protection appts, ABB traveling-wave protection criterion energy protection circuit overall length, but anti-interference energy
Power and tolerance transition resistance ability are weaker.SIEMENS improves the anti-interference ability of criterion, but time delay of action by way of integral
It is longer compared with ABB traveling-wave protection time delay of action.Under-voltage differential protection appts are aided with electric current using voltage derivative and under-voltage criterion as main criterion
Variable quantity and jump-value of current criterion exclude back side failure, protect generally as the standby of DC line main protection and traveling-wave protection
Shield.Protection Principle of Travelling Wave based on pole wave used by ABB, SIEMENS extracts the backward-travelling wave in voltage traveling wave by pole wave,
Breakdown judge is carried out by micro- grading mode again, and under-voltage differential protection appts then directly carry out breakdown judge according to voltage change ratio,
Therefore, there is a problem of that movement speed is slow, sensitivity is low in engineer application at present.
Summary of the invention
The present invention proposes a kind of DC line fast protection method and system, how in high sensitivity to solve in cog region
Outer failure, the problem of to be protected.
To solve the above-mentioned problems, according to an aspect of the invention, there is provided a kind of DC line fast protection method,
The described method includes:
When the corresponding dual-tree complex wavelet transform decomposition amount of the DC voltage of acquisition meets preset highly sensitive protection starting
When criterion, start highly sensitive protection；
If current DC voltage, which meets preset exception, counts greatly locking criterion, latch-up protection；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets preset failure criterion, protection is dynamic
For export.
Preferably, wherein the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset spirit
Sensitivity threshold value.
Preferably, wherein the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integration method, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference of DC voltage
Value.
Preferably, wherein the preset failure criterion includes: that the sub- criterion of bipolar failure and failure select extremely sub- criterion,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；
If λ5> WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；
λ7For preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
Preferably, if wherein the current corresponding dual-tree complex wavelet transform decomposition amount of DC voltage meets preset event
Hinder criterion, then protection act exports, comprising:
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets the sub- criterion of bipolar failure, bipolar guarantor
Shield movement outlet；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage, which meets failure, selects extremely sub- criterion, failure pole
Protection act outlet.
According to another aspect of the present invention, a kind of DC line rapid protection system is provided, the system comprises:
High sensitivity protection start unit is same as when the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage obtained is full
When the preset high sensitivity of foot protects start-up criterion, start highly sensitive protection；
Latch-up protection unit is latched guarantor if meeting preset exception for current DC voltage counts greatly locking criterion
Shield；
Protection act outlet port unit, if meeting for the current corresponding dual-tree complex wavelet transform decomposition amount of DC voltage pre-
If failure criterion, then protection act export.
Preferably, wherein the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset spirit
Sensitivity threshold value.
Preferably, wherein the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integrating system, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference of DC voltage
Value.
Preferably, wherein the preset failure criterion includes: that the sub- criterion of bipolar failure and failure select extremely sub- criterion,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；
If λ5> WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；
λ7For preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
Preferably, wherein the protection act outlet port unit, if the corresponding dual-tree complex wavelet transform of current DC voltage
Decomposition amount meets preset failure criterion, then protection act exports, comprising:
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets the sub- criterion of bipolar failure, bipolar guarantor
Shield movement outlet；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage, which meets failure, selects extremely sub- criterion, failure pole
Protection act outlet.
The present invention provides a kind of DC line fast protection method and systems, comprising: when the DC voltage of acquisition is corresponding
Dual-tree complex wavelet transform decomposition amount when meeting preset highly sensitive protection start-up criterion, start highly sensitive protection；If working as
Preceding DC voltage meets preset exception and counts locking criterion, then latch-up protection greatly；If the corresponding double trees of current DC voltage
Complex wavelet transform decomposition amount meets preset failure criterion, then protection act exports.The present invention high sensitivity protection starting after,
If meeting the sub- criterion of bipolar failure, extremely sub- criterion, bipolar protection direct action are selected without failure；If meeting failure selects pole
Sub- criterion, after determining failure extremely, failure pole protection act；If being judged to abnormal big number, direct latch-up protection；Energy of the present invention
It is enough to identify internal fault external fault fast and reliablely, there is higher sensitivity to high resistance earthing fault, while being suitable for LCC and VSC
System meets various demands.
Detailed description of the invention
By reference to the following drawings, exemplary embodiments of the present invention can be more fully understood by:
Fig. 1 is the flow chart according to the DC line fast protection method 100 of embodiment of the present invention；
Fig. 2 is the relay protective scheme figure according to embodiment of the present invention；
Fig. 3 is the schematic diagram according to the shifting window method of embodiment of the present invention；And
Fig. 4 is the structural schematic diagram according to the DC line rapid protection system 400 of embodiment of the present invention.
Specific embodiment
Exemplary embodiments of the present invention are introduced referring now to the drawings, however, the present invention can use many different shapes
Formula is implemented, and is not limited to the embodiment described herein, and to provide these embodiments be at large and fully disclose
The present invention, and the scope of the present invention is sufficiently conveyed to person of ordinary skill in the field.Show for what is be illustrated in the accompanying drawings
Term in example property embodiment is not limitation of the invention.In the accompanying drawings, identical cells/elements use identical attached
Icon note.
Unless otherwise indicated, term (including scientific and technical terminology) used herein has person of ordinary skill in the field
It is common to understand meaning.Further it will be understood that with the term that usually used dictionary limits, should be understood as and its
The context of related fields has consistent meaning, and is not construed as Utopian or too formal meaning.
Fig. 1 is the flow chart according to the DC line fast protection method 100 of embodiment of the present invention.As shown in Figure 1, this
The DC line fast protection method that the embodiment of invention provides is after high sensitivity protection starting, if meeting bipolar failure
Sub- criterion then selects extremely sub- criterion, bipolar protection direct action without failure；If meeting failure selects extremely sub- criterion, event is being determined
After hindering extremely, failure pole protection act；If being judged to abnormal big number, direct latch-up protection；The present invention can know fast and reliablely
Not Chu internal fault external fault, have higher sensitivity to high resistance earthing fault, while being suitable for LCC and VSC system, meet multi-party
The demand in face.The DC line fast protection method 100 that embodiments of the present invention provide is since step 101 place, in step
101 meet preset highly sensitive protection start-up criterion when the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage obtained
When, start highly sensitive protection.
Preferably, wherein the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset spirit
Sensitivity threshold value.
In step 102, if current DC voltage meets preset exception and counts locking criterion, latch-up protection greatly.
Preferably, wherein the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integration method, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference of DC voltage
Value.
In step 103, if the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets preset failure and sentences
According to then protection act exports.
Preferably, wherein the preset failure criterion includes: that the sub- criterion of bipolar failure and failure select extremely sub- criterion,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；
If λ5> WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；
λ7For preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
Preferably, if wherein the current corresponding dual-tree complex wavelet transform decomposition amount of DC voltage meets preset event
Hinder criterion, then protection act exports, comprising:
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets the sub- criterion of bipolar failure, bipolar guarantor
Shield movement outlet；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage, which meets failure, selects extremely sub- criterion, failure pole
Protection act outlet.
Fig. 2 is the relay protective scheme figure according to embodiment of the present invention.As shown in Fig. 2, in embodiments of the present invention, therefore
It includes: that monopole selects pole criterion and monopole criterion that barrier, which selects extremely sub- criterion,；The sub- criterion of bipolar failure and failure select extremely sub- criterion be or
Relationship after high sensitivity protection starting, if meeting the sub- criterion of bipolar failure, selects pole without failure when being protected
Sub- criterion, bipolar protection direct action；If meeting failure selects extremely sub- criterion, after determining failure extremely, failure pole protection act；
If meeting abnormal big number locking criterion, direct latch-up protection.
In embodiments of the present invention, the quick fast protection method of direct current is completed based on dual-tree complex wavelet transform.In base
When dual-tree complex wavelet transform decomposes all sampled points, one layer is decomposed frequency is reduced to original half, and two
Layer decomposes and frequency is reduced to original a quarter, and so on.In order to which dual-tree complex wavelet transform to be applied in protection, need
Meet the requirement that the point-by-point sampling of protection calculates, and study the shifting window algorithm for being suitable for dual-tree complex wavelet transform, as shown in Figure 3.
When carrying out convolution algorithm due to discrete signal and wavelet basis, boundary valid data Chang Yinqi length is long not as good as wavelet basis
It spends and causes not carrying out effective operation, high fdrequency component and the effective length of low frequency component can be because of wavelet basis length after transformation
It is different and corresponding variation occurs.In embodiments of the present invention, the wavelet basis length used is 19 point, in order to have
The faults feature of effect, a length of 20 points of the data window used herein.It is one mobile every time with 20 sampled points for 1 window
Sampling interval is calculated, then integrating range is the region of current point and 19 points composition before, due to 20 sampled datas
Available 5 data after two layers of decomposition frequency reducing twice, therefore the every movement of data window can once calculate a 5x1's
Data column are used for Protection criteria.
When the highly sensitive protection start-up criterion of progress judges, WSU is two layers points of dual-tree complex wavelet transform of DC voltage
Xie Liang, λ1For initiation value, sensitive can start through 300 1 sampled point of Ω transition resistance ground fault according to monopole outside area
Adjusting.
When the abnormal big number locking criterion of progress judges, according to voltage comparison method, then after protection starts, into exception
Big number locking criterion logic, if meeting U > λ2, then latch-up protection, λ2To act definite value.For example, according to 500 Ω of end in area
Transition resistance protects action message to adjust, and choosing safety factor is 1.2, then thinks to break down lower than 300kV when voltage,
Carry out the judgement of failure criterion logic.Otherwise after protection starting, if voltage is higher than 300kV, then it is assumed that be abnormal data, close
Lock protection.
Just when carrying out abnormal big number locking criterion and judging, according to voltage differential integration method, then right after protecting starting
Voltage integrates after first doing difference, and Difference Calculation formula is f ' (n)=f (n)-f (n-1), if integrated value meets in 0.6ms
∫ f ' (n) > λ3, then it is judged as abnormal data；Conversely, being then judged as failure, wherein setting λ3It is -150.This method is in 0.6ms
The interior abnormal big number that can prevent continuous 4 points.
When carrying out failure criterion judgement, two layers of decomposition first are done to voltage difference score value after protection starting, if meeting WSU
> λ5, then it is judged to bipolar failure；If meeting λ5> WSU > λ4With Δ Ucom> λ6It sets up simultaneously, it is determined that be cathode failure；If full
Sufficient λ5> WSU > λ4With Δ Ucom< λ7It sets up simultaneously, it is determined that be positive electrode fault.Wherein, λ4For the first preset failure threshold value；λ5
For the second preset failure threshold value；λ6For preset cathode fault threshold；λ7For preset positive electrode fault threshold value；△UcomFor direct current
Press the common mode amount U of UcomCalculus of differences value.λ4To act definite value, adjusted according to reliably external area error is escaped.
Fig. 4 is the structural schematic diagram according to the DC line rapid protection system 400 of embodiment of the present invention.Such as Fig. 4 institute
Show, the DC line rapid protection system 400 that embodiments of the present invention provide, comprising: high sensitivity protection start unit
401, latch-up protection unit 402 and protection act outlet port unit 403.
Preferably, the highly sensitive protection start unit 401 is same as when the corresponding double trees of the DC voltage obtained are multiple small
When wave conversion decomposition amount meets preset highly sensitive protection start-up criterion, start highly sensitive protection.
Preferably, wherein the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset spirit
Sensitivity threshold value.
Preferably, the latch-up protection unit 402, if meeting the number locking greatly of preset exception for current DC voltage
Criterion, then latch-up protection.
Preferably, wherein the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integrating system, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference of DC voltage
Value.
Preferably, the protection act outlet port unit 403, if becoming for the current corresponding dual-tree complex wavelet of DC voltage
It changes decomposition amount and meets preset failure criterion, then protection act exports.
Preferably, wherein the preset failure criterion includes: that the sub- criterion of bipolar failure and failure select extremely sub- criterion,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；
If λ5> WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；
λ7For preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
Preferably, wherein the protection act outlet port unit 403, if the corresponding dual-tree complex wavelet of current DC voltage becomes
It changes decomposition amount and meets preset failure criterion, then protection act exports, comprising: if the corresponding double trees of current DC voltage are multiple small
Wave conversion decomposition amount meets the sub- criterion of bipolar failure, then bipolar protection act outlet；If the corresponding double trees of current DC voltage
Complex wavelet transform decomposition amount meets failure and selects extremely sub- criterion, then failure pole protection act exports.
The DC line rapid protection system 400 of the embodiment of the present invention and the AC line of another embodiment of the invention
Road fast protection method 100 is corresponding, and details are not described herein.
The present invention is described by reference to a small amount of embodiment.However, it is known in those skilled in the art, as
Defined by subsidiary Patent right requirement, in addition to the present invention other embodiments disclosed above equally fall in it is of the invention
In range.
Normally, all terms used in the claims are all solved according to them in the common meaning of technical field
It releases, unless in addition clearly being defined wherein.All references " one/described/be somebody's turn to do [device, component etc.] " are all opened ground
At least one example being construed in described device, component etc., unless otherwise expressly specified.Any method disclosed herein
Step need not all be run with disclosed accurate sequence, unless explicitly stated otherwise.
It should be understood by those skilled in the art that, embodiments herein can provide as method, system or computer program
Product.Therefore, complete hardware embodiment, complete software embodiment or reality combining software and hardware aspects can be used in the application
Apply the form of example.Moreover, it wherein includes the computer of computer usable program code that the application, which can be used in one or more,
The computer program implemented in usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) produces
The form of product.
The application is referring to method, the process of equipment (system) and computer program product according to the embodiment of the present application
Figure and/or block diagram describe.It should be understood that every one stream in flowchart and/or the block diagram can be realized by computer program instructions
The combination of process and/or box in journey and/or box and flowchart and/or the block diagram.It can provide these computer programs
Instruct the processor of general purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices to produce
A raw machine, so that being generated by the instruction that computer or the processor of other programmable data processing devices execute for real
The device for the function of being specified in present one or more flows of the flowchart and/or one or more blocks of the block diagram.
These computer program instructions, which may also be stored in, is able to guide computer or other programmable data processing devices with spy
Determine in the computer-readable memory that mode works, so that it includes referring to that instruction stored in the computer readable memory, which generates,
Enable the manufacture of device, the command device realize in one box of one or more flows of the flowchart and/or block diagram or
The function of being specified in multiple boxes.
These computer program instructions also can be loaded onto a computer or other programmable data processing device, so that counting
Series of operation steps are executed on calculation machine or other programmable devices to generate computer implemented processing, thus in computer or
The instruction executed on other programmable devices is provided for realizing in one or more flows of the flowchart and/or block diagram one
The step of function of being specified in a box or multiple boxes.
Finally it should be noted that: the above embodiments are merely illustrative of the technical scheme of the present invention and are not intended to be limiting thereof, to the greatest extent
Invention is explained in detail referring to above-described embodiment for pipe, it should be understood by those ordinary skilled in the art that: still
It can be with modifications or equivalent substitutions are made to specific embodiments of the invention, and without departing from any of spirit and scope of the invention
Modification or equivalent replacement, should all cover within the scope of the claims of the present invention.
Claims (10)
1. a kind of DC line fast protection method, which is characterized in that the described method includes:
When the corresponding dual-tree complex wavelet transform decomposition amount of the DC voltage of acquisition meets preset highly sensitive protection start-up criterion
When, start highly sensitive protection；
If current DC voltage, which meets preset exception, counts greatly locking criterion, latch-up protection；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets preset failure criterion, protection act goes out
Mouthful.
2. the method according to claim 1, wherein the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset sensitivity
Threshold value.
3. according to the method described in claim 2, it is characterized in that, the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integration method, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference value of DC voltage.
4. according to the method described in claim 2, it is characterized in that, the preset failure criterion includes: that bipolar failure is sentenced
Extremely sub- criterion is selected according to failure,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；If λ5>
WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；λ7For
Preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
5. if according to the method described in claim 4, the it is characterized in that, corresponding dual-tree complex wavelet of the current DC voltage
Transformation decomposition amount meets preset failure criterion, then protection act exports, comprising:
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets the sub- criterion of bipolar failure, bipolar protection is dynamic
For export；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage, which meets failure, selects extremely sub- criterion, the protection of failure pole
Movement outlet.
6. a kind of DC line rapid protection system, which is characterized in that the system comprises:
High sensitivity protection start unit is same as when the corresponding dual-tree complex wavelet transform decomposition amount satisfaction of the DC voltage obtained is pre-
If highly sensitive protection start-up criterion when, start highly sensitive protection；
Latch-up protection unit, if meeting preset exception for current DC voltage counts greatly locking criterion, latch-up protection；
Protection act outlet port unit, if meeting for the current corresponding dual-tree complex wavelet transform decomposition amount of DC voltage preset
Failure criterion, then protection act exports.
7. system according to claim 6, which is characterized in that the preset highly sensitive protection start-up criterion are as follows:
If WSU > λ1It sets up, then starts highly sensitive protection；
Wherein, WSU is the corresponding dual-tree complex wavelet transform decomposition amount of DC voltage U；S is scaling function；λ1For preset sensitivity
Threshold value.
8. system according to claim 7, which is characterized in that the preset exception counts greatly locking criterion, comprising:
When using voltage comparison method, if U > λ2It sets up；Or
When using voltage differential integrating system, if ∫ f ' (n) > λ3It sets up, it is determined that for abnormal big number, latch-up protection；
Wherein, λ2For the first default lock-in threshold；λ3For the second default lock-in threshold；F ' (n) is the difference value of DC voltage.
9. system according to claim 7, which is characterized in that the preset failure criterion includes: that bipolar failure is sentenced
Extremely sub- criterion is selected according to failure,
The sub- criterion of bipolar failure are as follows: if WSU > λ5It sets up, it is determined that be bipolar failure；
The failure selects extremely sub- criterion are as follows: if λ5> WSU > λ4And Δ Ucom> λ6It sets up, it is determined that be cathode failure；If λ5>
WSU > λ4And Δ Ucom< λ7It sets up, it is determined that be positive electrode fault；
Wherein, λ4For the first preset failure threshold value；λ5For the second preset failure threshold value；λ6For preset cathode fault threshold；λ7For
Preset positive electrode fault threshold value；△UcomFor the common mode amount U of DC voltage UcomCalculus of differences value.
10. system according to claim 9, which is characterized in that the protection act outlet port unit, if current direct current
Corresponding dual-tree complex wavelet transform decomposition amount is pressed to meet preset failure criterion, then protection act exports, comprising:
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage meets the sub- criterion of bipolar failure, bipolar protection is dynamic
For export；
If the corresponding dual-tree complex wavelet transform decomposition amount of current DC voltage, which meets failure, selects extremely sub- criterion, the protection of failure pole
Movement outlet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910666471.9A CN110535104B (en) | 2019-07-23 | 2019-07-23 | Direct-current line rapid protection method and system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910666471.9A CN110535104B (en) | 2019-07-23 | 2019-07-23 | Direct-current line rapid protection method and system |
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| Publication Number | Publication Date |
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| CN110535104A true CN110535104A (en) | 2019-12-03 |
| CN110535104B CN110535104B (en) | 2022-07-01 |
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| CN201910666471.9A Active CN110535104B (en) | 2019-07-23 | 2019-07-23 | Direct-current line rapid protection method and system |
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| CN112202149A (en) * | 2020-06-23 | 2021-01-08 | 中国电力科学研究院有限公司 | Method and system for processing abnormal large number of direct-current transmission line protection based on voltage comparison method |
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| WO2018094862A1 (en) * | 2016-11-25 | 2018-05-31 | 许继集团有限公司 | Method for identifying single pole ground fault in vsc-dc power distribution network, and single pole ground fault protection method for vsc-dc power distribution network |
| CN109038515A (en) * | 2018-07-09 | 2018-12-18 | 中国电力科学研究院有限公司 | A kind of Hybrid HVDC route traveling-wave protection method and system based on Dual Tree Complex Wavelet variation |
| CN109119977A (en) * | 2018-09-20 | 2019-01-01 | 山东大学 | Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage |
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| WO2018094862A1 (en) * | 2016-11-25 | 2018-05-31 | 许继集团有限公司 | Method for identifying single pole ground fault in vsc-dc power distribution network, and single pole ground fault protection method for vsc-dc power distribution network |
| CN109038515A (en) * | 2018-07-09 | 2018-12-18 | 中国电力科学研究院有限公司 | A kind of Hybrid HVDC route traveling-wave protection method and system based on Dual Tree Complex Wavelet variation |
| CN109119977A (en) * | 2018-09-20 | 2019-01-01 | 山东大学 | Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112202149A (en) * | 2020-06-23 | 2021-01-08 | 中国电力科学研究院有限公司 | Method and system for processing abnormal large number of direct-current transmission line protection based on voltage comparison method |
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