CN105356522A - Enhancing method of direct-current feed-in weak alternating-current system - Google Patents
Enhancing method of direct-current feed-in weak alternating-current system Download PDFInfo
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- CN105356522A CN105356522A CN201510713384.6A CN201510713384A CN105356522A CN 105356522 A CN105356522 A CN 105356522A CN 201510713384 A CN201510713384 A CN 201510713384A CN 105356522 A CN105356522 A CN 105356522A
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- weak
- direct current
- current feed
- short circuit
- effective short
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J5/00—Circuit arrangements for transfer of electric power between ac networks and dc 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
- H02H7/261—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 involving signal transmission between at least two stations
- H02H7/262—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 involving signal transmission between at least two stations involving transmissions of switching or blocking orders
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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
- H02H7/267—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 parallel lines and wires
-
- 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
Abstract
The invention relates to an enhancing method of a direct-current feed-in weak alternating-current system. The method comprises the steps of: calculating an effective short-current ratio of each converter station of each direct-current feed-in alternating-current system, and determining that the direct-current feed-in alternating-current system, which is characterized in that the effective short-current ratios of the converter stations are no higher than an effective short-current ratio reference value, is a direct-current feed-in weak alternating-current system; then successively switching off N lines in the direct-current feed-in weak alternating-current system, obtaining N effective short-current ratios by calculation, and ordering the effective short-current ratios, wherein the N-1 lines corresponding to the lowest effective short-current ratio are weak points of the direct-current feed-in weak alternating-current system; and then adopting a line adding series compensation device or a line adding mode to enhance the weak points of the direct-current feed-in weak alternating-current system, repeating the above steps and enhancing the direct-current feed-in weak alternating-current system until the effective short-current ratios of all the converter stations are respectively larger than the effective short-current ratio reference value. By adopting the enhancing method of a direct-current feed-in weak alternating-current system, the safety stability of a direct-current power transmission system is effectively enhanced.
Description
Technical field
The present invention relates to power system safety and stability control field, particularly relate to a kind of Enhancement Method of direct current feed-in weak AC system.
Background technology
In order to meet the demand of energy transfer, DC transmission engineering voltage is more and more higher, transmission capacity is increasing, fed distance is more and more far away, especially the huge electrical network of complexity of alternating current-direct current mixing transmission of electricity, send direct current, the impact of receiving end AC system and interconnected network is also increasing.When after the sending end current conversion station and receiving end current conversion station incoming transport electrical network of DC transmission system, the material impact that can produce existing AC system; Add, large hydropower station is usually located at remote mountain area, and these regional geologies, geographical conditions are severe, cause the addressing of sending end current conversion station comparatively difficult; Simultaneously, electric network composition is weaker, sending end current conversion station incoming transport system is more weak, especially a basin water power station forms a sending end electrical network, multiple direct current is sent outside simultaneously, so, the influencing each other of many direct currents of sending end direct current feed-in AC system directly affects the safe and stable operation of electric power system.Moreover, for making full use of the channel resource of direct current feed-in AC system, receiving end current conversion station also may drop on the more weak province of AC system (district) and exchange section entry and exit place, fall into the AC system that the more weak province of AC system (district) exchanges section entry and exit place, be direct current feed-in AC system.
Direct current feed-in weak AC system is in running, there is direct current feed-in weak AC system voltage collapse, harmonic instability, overvoltage exceed standard, sub-synchronous oscillation, inverter continue a series of potential risks such as commutation failure can not recover, the weak spot that these easily cause direct current feed-in weak AC system voltage collapse, harmonic instability, overvoltage exceeds standard, sub-synchronous oscillation, inverter continue a series of potential risks such as commutation failure can not recover circuit is referred to as direct current feed-in weak AC system.
These weak spots once there is the situation such as voltage collapse, harmonic instability, will cause unpredictable consequence to DC transmission system, seriously have impact on the security and stability of DC power transmission line in running.
Summary of the invention
Based on this, be necessary the technical problem of the security and stability deficiency for DC transmission system, a kind of Enhancement Method of direct current feed-in weak AC system is provided.
An Enhancement Method for direct current feed-in weak AC system, comprises the steps:
S1, calculates effective short circuit ratio of each current conversion station of direct current feed-in AC system, if effective short circuit ratio of described current conversion station is not higher than effective short circuit ratio reference value, judges that described direct current feed-in AC system is as direct current feed-in weak AC system;
S2, for the N bar circuit in described direct current feed-in weak AC system, first disconnects arbitrary circuit wherein, calculates effective short circuit ratio of now described direct current feed-in weak AC system; Wherein, N is the number of lines of direct current feed-in weak AC system;
S3, disconnect arbitrary circuit in remaining N-1 bar circuit in described direct current feed-in weak AC system again, calculate effective short circuit ratio of now described direct current feed-in weak AC system, until disconnected by the N bar circuit in described direct current feed-in weak AC system successively, and calculate N number of effective short circuit ratio of described direct current feed-in weak AC system;
S4, sorts to described effective short circuit ratio, the N-1 bar circuit that minimum effective short circuit ratio is corresponding, is the weak spot of described direct current feed-in weak AC system;
S5, adopts the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional to strengthen;
S6, repeated execution of steps S1 to S5, strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.
The Enhancement Method of direct current feed-in weak AC system of the present invention, by calculating effective short circuit ratio of each current conversion station of direct current feed-in AC system, the effective short circuit ratio judging current conversion station not higher than the direct current feed-in AC system of effective short circuit ratio reference value as direct current feed-in weak AC system; Disconnect the N bar circuit in described direct current feed-in weak AC system more successively, calculate N number of effective short circuit ratio, and described effective short circuit ratio is sorted, wherein, the N-1 bar circuit that minimum effective short circuit ratio is corresponding is the weak spot of described direct current feed-in weak AC system; Then, the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional is adopted to strengthen, repeat above-mentioned steps to strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.Adopt the Enhancement Method of direct current feed-in weak AC system of the present invention, the probability that the weak spot greatly reducing direct current feed-in weak AC system breaks down, effectively enhance the stability of direct current feed-in weak AC system, further ensure the security and stability of DC transmission system.
Accompanying drawing explanation
Fig. 1 is the Enhancement Method flow chart of the direct current feed-in weak AC system of one embodiment of the present of invention.
Embodiment
In order to further set forth the technological means that the present invention takes and the effect obtained, below in conjunction with accompanying drawing and preferred embodiment, to technical scheme of the present invention, carry out clear and complete description.
As shown in Figure 1, Fig. 1 is the Enhancement Method flow chart of the direct current feed-in weak AC system of one embodiment of the present of invention.
An Enhancement Method for direct current feed-in weak AC system, can comprise the steps:
Step S1, calculates effective short circuit ratio of each current conversion station of direct current feed-in AC system, if effective short circuit ratio of described current conversion station is not higher than effective short circuit ratio reference value, judges that described direct current feed-in AC system is as direct current feed-in weak AC system;
In this step, by calculating effective short circuit ratio of each current conversion station of direct current feed-in AC system, if effective short circuit ratio of current conversion station is not higher than effective short circuit ratio reference value, then judge that this direct current feed-in AC system is as direct current feed-in weak AC system, in subsequent step, the direct current feed-in weak AC system judged is strengthened; If effective short circuit ratio of current conversion station is higher than effective short circuit ratio reference value, so, this direct current feed-in AC system is non-dc feed-in weak AC system, in the present invention, does not strengthen non-dc feed-in weak AC system.
Step S2, for the N bar circuit in direct current feed-in weak AC system, first disconnects arbitrary circuit wherein, calculates effective short circuit ratio of now described direct current feed-in weak AC system; Wherein, N is the number of lines of direct current feed-in weak AC system;
In this step, for the N bar circuit in direct current feed-in weak AC system, need arbitrary the circuit first disconnected wherein, calculate effective short circuit ratio of the direct current feed-in weak AC system current conversion station of remaining N-1 circuit.
Step S3, disconnect arbitrary circuit in remaining N-1 bar circuit in described direct current feed-in weak AC system again, calculate effective short circuit ratio of now described direct current feed-in weak AC system, until disconnected by the N bar circuit in described direct current feed-in weak AC system successively, and calculate N number of effective short circuit ratio of described direct current feed-in weak AC system;
In this step, first to connect that circuit that step S2 disconnects, disconnect arbitrary circuit in remaining N-1 bar circuit in addition again, calculate effective short circuit ratio of the direct current feed-in weak AC system current conversion station of N-1 circuit remaining in this step, until disconnected by the N bar circuit in this direct current feed-in weak AC system successively, and calculate N number of effective short circuit ratio of this direct current feed-in weak AC system.
It should be noted that, when calculating effective short circuit ratio of direct current feed-in weak AC system current conversion station, only have a circuit to be disconnected, and each circuit disconnected is different at every turn.
Step S4, sorts to above-mentioned effective short circuit ratio, the N-1 bar circuit that minimum effective short circuit ratio is corresponding, is the weak spot of described direct current feed-in weak AC system;
In this step, N number of effective short circuit ratio that step S3 obtains sorted, so, N-1 bar circuit corresponding to minimum short circuit ratio is the weak spot of described direct current feed-in weak AC system.
It should be noted that, those easily cause direct current feed-in weak AC system voltage collapse, harmonic instability, weak spot that overvoltage exceeds standard, sub-synchronous oscillation, inverter continue a series of potential risks such as commutation failure can not recover circuit is direct current feed-in weak AC system.
Step S5, adopts the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional to strengthen;
In this step, strengthen by adopting the weak spot of mode to the direct current feed-in weak AC system judged in step S4 that circuit installs series compensation device or newly-increased circuit additional, the probability that the weak spot of direct current feed-in weak AC system is broken down reduces greatly, effectively ensure that the security and stability of DC transmission system.
Certainly, also two kinds of modes can be combined the weak spot be applied to direct current feed-in weak AC system flexibly to strengthen.
Step S6, repeated execution of steps S1 to S5, strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.
In this step, by repeating the above-mentioned step strengthened the weak spot of direct current feed-in weak AC system, direct current feed-in weak AC system is strengthened, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system, this assures the security and stability of whole direct current feed-in weak AC system.
The Enhancement Method of direct current feed-in weak AC system of the present invention, by calculating effective short circuit ratio of each current conversion station of direct current feed-in AC system, the effective short circuit ratio judging current conversion station not higher than the direct current feed-in AC system of effective short circuit ratio reference value as direct current feed-in weak AC system; Disconnect the N bar circuit in described direct current feed-in weak AC system more successively, calculate N number of effective short circuit ratio, and described effective short circuit ratio is sorted, wherein, the N-1 bar circuit that minimum effective short circuit ratio is corresponding is the weak spot of described direct current feed-in weak AC system; Then, the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional is adopted to strengthen, repeat above-mentioned steps to strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.Adopt the Enhancement Method of direct current feed-in weak AC system of the present invention, the probability that the weak spot greatly reducing direct current feed-in weak AC system breaks down, effectively enhance the stability of direct current feed-in weak AC system, further ensure the security and stability of DC transmission system.
Wherein in an embodiment, the Enhancement Method of direct current feed-in weak AC system of the present invention, can also comprise the steps:
Simulation calculation is carried out to the direct current feed-in weak AC system after strengthening, checks the direct current after generation three phase short circuit fault of the direct current feed-in weak AC system after strengthening and can recover normal operation;
If the direct current after generation three phase short circuit fault of the direct current feed-in weak AC system after strengthening can not recover normal operation, repeat above-mentioned steps, the direct current feed-in weak AC system after described enhancing is strengthened again.
In the huge electrical network of complexity of alternating current-direct current mixing transmission of electricity, when after the sending end current conversion station and receiving end current conversion station incoming transport electrical network of DC transmission system, the material impact that can produce existing AC system, such as, the change of direct current transmission power, the transfer of AC system trend can be caused or give, the imbalance of receiving-end system power; AC network, by disturbance or after breaking down, equally also can affect the normal work of DC converter, once cause commutation failure, can react on AC network, forms the interaction between ac and dc systems.
By above-mentioned steps, effectively ensure that the direct current after generation three phase short circuit fault of the direct current feed-in weak AC system after enhancing can recover normal operation, efficiently avoid influencing each other of ac and dc systems, ensure that the safe and stable operation of DC transmission system.
Wherein in an embodiment, the Enhancement Method of direct current feed-in weak AC system of the present invention, can adopt electromagnetic transient state procedure EMTDC to carry out simulation calculation to the direct current feed-in weak AC system after enhancing.
Wherein in an embodiment, the Enhancement Method of direct current feed-in weak AC system of the present invention, effective short circuit ratio reference value is 2.
The Enhancement Method of direct current feed-in weak AC system of the present invention, by calculating effective short circuit ratio of each current conversion station of direct current feed-in AC system, the effective short circuit ratio judging current conversion station not higher than the direct current feed-in AC system of effective short circuit ratio reference value as direct current feed-in weak AC system; Disconnect the N bar circuit in described direct current feed-in weak AC system more successively, calculate N number of effective short circuit ratio, and described effective short circuit ratio is sorted, wherein, the N-1 bar circuit that minimum effective short circuit ratio is corresponding is the weak spot of described direct current feed-in weak AC system; Then, the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional is adopted to strengthen, repeat above-mentioned steps to strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.Adopt the Enhancement Method of direct current feed-in weak AC system of the present invention, the probability that the weak spot greatly reducing direct current feed-in weak AC system breaks down, effectively enhance the stability of direct current feed-in weak AC system, further ensure the security and stability of DC transmission system.
Each technical characteristic of the above embodiment can combine arbitrarily, for making description succinct, the all possible combination of each technical characteristic in above-described embodiment is not all described, but, as long as the combination of these technical characteristics does not exist contradiction, be all considered to be the scope that this specification is recorded.
The above embodiment only have expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but can not therefore be construed as limiting the scope of the patent.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.
Claims (4)
1. an Enhancement Method for direct current feed-in weak AC system, is characterized in that, comprises the steps:
S1, calculates effective short circuit ratio of each current conversion station of direct current feed-in AC system, if effective short circuit ratio of described current conversion station is not higher than effective short circuit ratio reference value, judges that described direct current feed-in AC system is as direct current feed-in weak AC system;
S2, for the N bar circuit in described direct current feed-in weak AC system, first disconnects arbitrary circuit wherein, calculates effective short circuit ratio of now described direct current feed-in weak AC system; Wherein, N is the number of lines of direct current feed-in weak AC system;
S3, disconnect arbitrary circuit in remaining N-1 bar circuit in described direct current feed-in weak AC system again, calculate effective short circuit ratio of now described direct current feed-in weak AC system, until disconnected by the N bar circuit in described direct current feed-in weak AC system successively, and calculate N number of effective short circuit ratio of described direct current feed-in weak AC system;
S4, sorts to described effective short circuit ratio, the N-1 bar circuit that minimum effective short circuit ratio is corresponding, is the weak spot of described direct current feed-in weak AC system;
S5, adopts the weak spot of mode to described direct current feed-in weak AC system that circuit installs series compensation device or newly-increased circuit additional to strengthen;
S6, repeated execution of steps S1 to S5, strengthen direct current feed-in weak AC system, until effective short circuit ratio of all current conversion stations is all greater than described effective short circuit ratio reference value in direct current feed-in weak AC system.
2. the Enhancement Method of direct current feed-in weak AC system according to claim 1, is characterized in that, also comprise:
Simulation calculation is carried out to the direct current feed-in weak AC system after strengthening, checks the direct current after generation three phase short circuit fault of the direct current feed-in weak AC system after strengthening and can recover normal operation;
If the direct current after generation three phase short circuit fault of the direct current feed-in weak AC system after strengthening can not recover normal operation, repeated execution of steps S1 to S6, the direct current feed-in weak AC system after described enhancing is strengthened again.
3. the Enhancement Method of direct current feed-in weak AC system according to claim 2, is characterized in that: adopt electromagnetic transient state procedure EMTDC to carry out simulation calculation to the direct current feed-in weak AC system after enhancing.
4. the Enhancement Method of direct current feed-in weak AC system according to claim 1, is characterized in that, described effective short circuit ratio reference value is 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510713384.6A CN105356522A (en) | 2015-10-27 | 2015-10-27 | Enhancing method of direct-current feed-in weak alternating-current system |
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| CN201510713384.6A CN105356522A (en) | 2015-10-27 | 2015-10-27 | Enhancing method of direct-current feed-in weak alternating-current system |
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| CN105356522A true CN105356522A (en) | 2016-02-24 |
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| CN201510713384.6A Pending CN105356522A (en) | 2015-10-27 | 2015-10-27 | Enhancing method of direct-current feed-in weak alternating-current system |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013027177A (en) * | 2011-07-21 | 2013-02-04 | Sumitomo Electric Ind Ltd | Electricity distribution system |
| CN103094905A (en) * | 2013-01-07 | 2013-05-08 | 广东电网公司电网规划研究中心 | Selection method of dynamic reactive power compensation configuration point |
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- 2015-10-27 CN CN201510713384.6A patent/CN105356522A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013027177A (en) * | 2011-07-21 | 2013-02-04 | Sumitomo Electric Ind Ltd | Electricity distribution system |
| CN103094905A (en) * | 2013-01-07 | 2013-05-08 | 广东电网公司电网规划研究中心 | Selection method of dynamic reactive power compensation configuration point |
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Application publication date: 20160224 |