CN112924784A - Method, system and diagnosis device for judging commutation failure of direct-current power transmission system - Google Patents
Method, system and diagnosis device for judging commutation failure of direct-current power transmission system Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Abstract
The invention relates to safety and stability analysis and control of a power system, and provides a method, a system and a diagnosis device for judging commutation failure of a direct-current power transmission system aiming at the problem of insufficient accuracy of voltage criterion of commutation failure of the direct-current power transmission system. Obtaining the critical voltage V representing the stable state of the DC power transmission system after the AC system failsHAnd a critical voltage V characterizing an unstable state of the DC transmission systemL(ii) a Will VHAnd VLThe formed voltage interval is used as a voltage risk band of commutation failure to judge the commutation failure of the direct current transmission system, and when the alternating current voltage is higher than VHThe DC power transmission system will not have phase change failure, when the AC voltage is lower than VLIf the alternating-current voltage falls into the risk zone, indicating that the risk of the commutation failure of the direct-current power transmission system is higher; compared with the prior art, the method can be more accurateAnd judging the commutation failure condition of the direct current power transmission system according to the alternating current voltage state.
Description
Technical Field
The invention relates to safety and stability analysis and control of a power system, in particular to a method, a system and a diagnosis device for judging commutation failure of a direct-current power transmission system.
Background
The energy center and the load gravity center in China are geographically reversely distributed, and in order to effectively solve the problem of trans-regional transmission of energy, a high-voltage direct-current power transmission system based on a power grid commutation converter type is widely applied due to the advantages of the high-voltage direct-current power transmission system on large-capacity long-distance transmission. Commutation failure is one of the most common faults of a direct current transmission system, and causes adverse effects on aspects such as direct current line power transmission, reactive voltage stability, transient stability and the like, so whether the first commutation failure after the alternating current system fault can be accurately judged is an important problem in the field of safety and stability analysis and control of a power system. However, the direct current, the alternating voltage and other electrical quantities are used as criteria for the commutation failure, and the mutual influence and transient change of the electrical quantities among the alternating current and direct current power transmission systems are not fully considered, so that the accuracy of the commutation failure judgment is questioned, and the criteria do not have a corresponding relation.
Disclosure of Invention
The invention provides a method, a system and a diagnosis device for judging commutation failure of a direct current power transmission system aiming at the problem of insufficient accuracy of current commutation failure criterion of the direct current power transmission system.
In some disclosures, the invention provides a method for judging the commutation failure of the direct-current power transmission system, and compared with the existing method, the method can judge the commutation failure condition of the direct-current power transmission system more accurately according to the alternating-current voltage state.
The technical scheme adopted by the invention is as follows:
as shown in fig. 1, a method for determining a commutation failure of a dc power transmission system includes the following steps: when the AC system fails, the critical voltage V representing the stable state of the DC power transmission system after the AC system fails is obtainedHAnd a critical voltage V characterizing an unstable state of the DC transmission systemL；
The V is put intoHAnd said VLThe formed voltage interval is used as a voltage risk band of phase commutation failure, and the phase commutation failure of the direct current transmission system is judged;
when the AC voltage is higher than VHIf the direct current transmission system fails to change the phase, the direct current transmission system does not fail to change the phase; when the AC voltage is lower than VLIf so, the direct current transmission system must have phase commutation failure; and when the alternating voltage falls in the risk band, indicating that the commutation of the direct current transmission system has failure risk.
In some disclosures, the critical voltage V characterizing steady state of a dc power transmission systemHThe specific method comprises the following steps:
the expression of the extinction angle of the direct-current power transmission system is shown as the formula (1):
in the formula: k is the transformation ratio of the converter transformer; i isdIs direct current; xcIs a commutation reactance; u shapeLLThe voltage effective value of the inversion side commutation bus is obtained; beta is a trigger lead angle;
representing the commutation voltage zero crossing offset angle.
According to the equivalent circuit of the direct current transmission system, the direct current can be represented by equation (2):
in the formula: u shapedr0And Udi0Respectively representing ideal no-load direct-current voltage of a rectifying side and an inverting side; rLIs a direct current resistance; rcrAnd RciRespectively representing equivalent phase change resistances of a rectifying side and an inverting side; α represents a commutation side firing angle; γ represents the inversion side arc-quenching angle.
The relationship between the voltages of the alternating current system and the direct current transmission system is shown in formula (3):
in the formula: u shapediAnd IdDirect current voltage and current respectively; u shapedi0Is an ideal no-load direct current voltage; b is the number of bridges connected in series; k is the transformation ratio of the converter transformer; u shapeLLAnd the effective value of the voltage of the converter bus is represented.
When the AC system is in fault, if the trigger advance angle is not changed in a short time, substituting the expressions (2) and (3) into the expression (1) and substituting the limit extinction angle to obtain a voltage value VHShould be above the true threshold voltage causing phase commutation failure.
In the formula: k is the transformation ratio of the converter transformer, Udr0Representing an ideal no-load DC voltage, X, at the rectifying sideciIs an equivalent phase-change reactance of the inversion side, alpharIndicating commutation side firing angle, betaiIndicating the inverse side trigger advance angle, gammaminFor the inversion side limit extinction angle, B represents the number of series bridges, ReqRepresents the equivalent resistance, Req＝Rcr+RL-RciAnd has Rcr＝(3/π)Xcr；Rci＝(3/π)Xci。
In some disclosures, the characterizationCritical voltage V of DC power transmission system in unstable stateLThe specific method comprises the following steps:
when an alternating current system fails, if the amplitude of the alternating current voltage drops rapidly, the trigger advance angle can be considered not to change suddenly in a short time, and the changed direct current is as shown in a formula (5)
In the formula: u'LRepresenting the effective value of the voltage of the current conversion bus line after the change; γ' represents the changed extinction angle.
From this, the relationship before and after the change of the DC current can be obtained, as shown in the formula (6)
Assuming that the influence of the ac voltage drop on the dc current rise after the fault is simplified to a linear relationship, it can be expressed as:
I′d＝UdiId/U′di (7)
in the formula: u shapediAnd IdThe direct current voltage and the direct current before the fault are obtained; u'diAnd l'dThe direct current voltage and the direct current after the fault.
The equations of the coupling type (5), (6) and (7) can be obtained as follows
Substituting the limit extinction angle to obtain a voltage value VHShould be below the true threshold voltage causing commutation failure:
in some disclosures, the voltage risk band of commutation failure is specifically as follows:
in order to determine the voltage risk band of phase commutation failure, the zero crossing point offset angle of the phase commutation voltage needs to be further acquired. When an asymmetric fault occurs, the relation between the amplitude drop of the phase voltage of the commutation bus and the zero crossing point offset angle is given by related research as shown in the formula (10):
in the equation, Δ U represents a drop in the phase voltage amplitude.
And the line voltage of the converter bus after the fault can be obtained by the formula (11):
therefore, the line voltage amplitude drop of the commutation bus can be obtained by (12):
where Δ V represents the line voltage amplitude droop.
The phase voltage amplitude droop in equation (10) can be represented by the line voltage amplitude droop:
therefore, the line voltage amplitude dip can be used to characterize the phase-change voltage offset angle, and the left side of the equations (4) and (9) can be expressed as 1- Δ V.
The critical voltage V considering the phase-change voltage offset angle can be estimated by numerical analysis based on the formulas (4), (9), (10) and (13)LAnd VHWhen the AC voltage is higher than VHThe DC power transmission system will not have phase change failure, when the AC voltage is lower than VLThe direct current transmission system must have phase commutation failure and will be in the interval(VL，VH) Defined as the voltage risk band for phase commutation failure. When the alternating voltage falls in the risk band, the risk of commutation failure of the direct current transmission system is high. In particular, when three-phase symmetrical fault occurs in AC system, commutation voltage is deviated by angle
Is 0, the accurate threshold voltage can be obtained at this time, as shown in equation (13):
in some disclosures, the invention provides a system for judging the commutation failure of a direct-current power transmission system, and compared with the existing method, the system can judge the commutation failure condition of the direct-current power transmission system more accurately according to the alternating-current voltage state.
The technical scheme adopted by the invention is as follows:
a discrimination system for commutation failure of a direct current transmission system comprises a commutation failure critical voltage acquisition module and a commutation failure on-line monitoring module;
the commutation failure critical voltage acquisition module is used for acquiring current operation state data of a power grid, executing the method and acquiring a commutation failure risk zone;
the online commutation failure monitoring module is used for monitoring the real-time commutation bus voltage condition of the alternating current system and judging, and when the alternating current voltage is higher than the highest critical value of the commutation failure risk band, the direct current transmission system cannot generate commutation failure; when the alternating-current voltage is lower than the lowest critical value of the phase failure risk band, the direct-current power transmission system is bound to have phase change failure; and when the alternating voltage falls in the risk band, indicating that the commutation of the direct current transmission system has failure risk.
And establishing a unique mapping relation between the judgment index of the commutation failure of the direct-current power transmission system and the stable state of the direct-current power transmission system instead of the commutation failure event, thereby representing the stable state and the commutation failure risk of the direct-current power transmission system more accurately.
In some disclosures, the invention provides a device for diagnosing commutation failure of a direct-current power transmission system, and compared with the existing method, the device can judge the commutation failure condition of the direct-current power transmission system more accurately according to the alternating-current voltage state.
The technical scheme adopted by the invention is as follows:
a device for diagnosing commutation failure in a dc power transmission system, comprising a storage medium having stored thereon an acquirer program which when read causes a processor to perform the method disclosed above.
And establishing a unique mapping relation between the judgment index of the commutation failure of the direct-current power transmission system and the stable state of the direct-current power transmission system instead of the commutation failure event, thereby representing the stable state and the commutation failure risk of the direct-current power transmission system more accurately.
Advantageous effects
The method establishes a unique mapping relation between the judgment index and the stable state of the direct current power transmission system instead of the commutation failure event, thereby representing the stable state and the commutation failure risk of the direct current power transmission system more accurately.
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In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is a flow chart of a discrimination method of the present disclosure;
fig. 2 shows the risk band of commutation failure voltage for each dc return.
Detailed Description
The technical solutions provided by the present invention will be described in detail below with reference to specific examples, and it should be understood that the following specific embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention.
For evaluating the effectiveness of the proposed commutation failure voltage risk band, based on PSCAD/EMTDCThe CIGRE reference model of (1) is simulated. Based on the equations (4), (9), (10), (12), when the critical extinction angle is 7 °, the voltage index of the asymmetric fault can be estimated as VL＝0.950p.u.，VH0.974 p.u. For three-phase symmetry faults, the index V can be obtained by using the index (13)L0.940p.u. and VHThis is consistent with theoretical analysis that the higher indicators of theoretical analysis for asymmetric faults are from zero-crossing phase shift angles.
The critical voltage interval of the first commutation failure of each return direct current is obtained and obtained based on certain actual power grid operation mode data and is shown in fig. 2, and a commutation failure voltage risk zone formed by two voltage indexes can be clearly seen. The trigger advance angle and the extinction angle of different direct current transmission systems in steady state operation do not change greatly, so V is influencedLThe main factor of the size is the initial effective value of the voltage of the converter bus, which is related to the initial running state of the AC-DC hybrid power grid. And VHMainly depending on the intrinsic parameters of the dc transmission system. Therefore, when the grid structure or the operation mode of the alternating current power grid is changed, the critical voltage interval and the boundary value thereof cannot be greatly changed. According to the method, even if the accurate commutation failure critical voltage cannot be obtained, the stable state of the alternating current-direct current hybrid power grid can be accurately judged based on the corresponding assumed condition.
Claims (10)
1. A method for judging commutation failure of a direct current power transmission system is characterized by comprising the following steps:
when the AC system fails, the critical voltage V representing the stable state of the DC power transmission system after the AC system fails is obtainedHAnd a critical voltage V characterizing an unstable state of the DC transmission systemL；
The V is put intoHAnd said VLThe formed voltage interval is used as a voltage risk band of phase commutation failure, and the phase commutation failure of the direct current transmission system is judged;
when the AC voltage is higher than VHIf the direct current transmission system fails to change the phase, the direct current transmission system does not fail to change the phase; when the AC voltage is lower than VLIf the direct current transmission system is sure to transmitFailed in the original commutation; and when the alternating voltage falls in the risk band, indicating that the commutation of the direct current transmission system has failure risk.
2. The method according to claim 1, wherein the trigger advance angle is set to be constant in a short time after the ac system fails, and a critical voltage V representing the steady state of the dc power transmission system after the ac system fails is obtained based on the limit extinction angle of the dc systemH。
3. The method according to claim 2, wherein the threshold voltage V representing the steady state of the DC power transmission system is a voltage level that is lower than the threshold voltage V representing the steady state of the DC power transmission systemH，
In the formula: k is the transformation ratio of the converter transformer, Udr0Representing an ideal no-load DC voltage, X, at the rectifying sideciIs an equivalent phase-change reactance of the inversion side, alpharIndicating commutation side firing angle, betaiIndicating the inverse side trigger advance angle, gammaminFor the inversion side limit extinction angle, B represents the number of series bridges, ReqRepresents the equivalent resistance, Req＝Rcr+RL-RciAnd has Rcr＝(3/π)Xcr；Rci＝(3/π)Xci。
4. The method according to claim 1, wherein the method for determining the commutation failure of the dc power transmission system is characterized in that the critical voltage V representing the unstable state of the dc system is obtained based on the limit extinction angle of the dc system on the basis of the linear relationship between the ac voltage drop and the dc current rise when the ac system failsL。
5. A direct current according to claim 4The method for judging the commutation failure of the power transmission system is characterized in that the critical voltage V for representing the unstable state of the direct-current power transmission systemL，
Gamma-inverter side extinction angle; u shapeLLThe voltage effective value of the inversion side commutation bus is obtained; beta is a trigger lead angle;
representing the commutation voltage zero crossing offset angle.
6. The method for judging the commutation failure of the direct current transmission system according to claim 2 or 4, wherein when the alternating current system has a three-phase asymmetric fault, the amplitude change of the phase voltage takes the amplitude change of the line voltage as a reference to obtain the zero-crossing point offset angle of the commutation voltage.
7. The method according to claim 6, wherein the phase voltage amplitude changes
8. A method as claimed in claim 2 or 4, wherein the voltage offset angle is determined when a three-phase fault occurs in the AC system
0, the critical voltage V representing the unstable state of the direct current transmission systemLSaid critical voltage V characterizing the steady state of the DC transmission systemHComprises the following steps:
9. a discrimination system for commutation failure of a direct current transmission system is characterized by comprising a commutation failure critical voltage acquisition module and a commutation failure on-line monitoring module;
the commutation failure critical voltage acquisition module is used for acquiring current operation state data of a power grid, executing the method of any one of claims 1 to 8 and acquiring a commutation failure risk band;
the online commutation failure monitoring module is used for monitoring the real-time commutation bus voltage condition of the alternating current system and judging, and when the alternating current voltage is higher than the highest critical value of the commutation failure risk band, the direct current transmission system cannot generate commutation failure; when the alternating-current voltage is lower than the lowest critical value of the phase failure risk band, the direct-current power transmission system is bound to have phase change failure; and when the alternating voltage falls in the risk band, indicating that the commutation of the direct current transmission system has failure risk.
10. A device for diagnosing commutation failure in a dc power transmission system, comprising a storage medium having stored thereon an acquirer program, wherein the acquirer program, when read, causes a processor to perform the method of any one of claims 1-8.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113433426A (en) * | 2021-08-30 | 2021-09-24 | 国网江西省电力有限公司电力科学研究院 | Method and device for calculating critical fault position of converter bus of direct-current transmission system |
| CN113484578A (en) * | 2021-07-14 | 2021-10-08 | 南方电网科学研究院有限责任公司 | Commutation state detection method, device and equipment of high-voltage direct current system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104267288A (en) * | 2014-10-08 | 2015-01-07 | 国家电网公司 | HVDC commutation failure fault diagnosis method based on valve voltages or valve currents |
| CN104407195A (en) * | 2014-10-31 | 2015-03-11 | 广东电网有限责任公司电力调度控制中心 | Asymmetric fault short circuit current detection method for AC-DC hybrid system |
| CN109617107A (en) * | 2018-11-19 | 2019-04-12 | 国网浙江省电力有限公司电力科学研究院 | A kind of appraisal procedure of multi-infeed HVDC system DC support ability and commutation failure |
| CN110441658A (en) * | 2019-08-27 | 2019-11-12 | 国网新疆电力有限公司经济技术研究院 | A kind of high voltage direct current commutation failure method of discrimination considering DC current variation |
| CN111007360A (en) * | 2019-12-27 | 2020-04-14 | 新疆大学 | Extra-high voltage direct current transmission system commutation failure judgment method considering current change |
-
2021
- 2021-01-28 CN CN202110117455.1A patent/CN112924784A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104267288A (en) * | 2014-10-08 | 2015-01-07 | 国家电网公司 | HVDC commutation failure fault diagnosis method based on valve voltages or valve currents |
| CN104407195A (en) * | 2014-10-31 | 2015-03-11 | 广东电网有限责任公司电力调度控制中心 | Asymmetric fault short circuit current detection method for AC-DC hybrid system |
| CN109617107A (en) * | 2018-11-19 | 2019-04-12 | 国网浙江省电力有限公司电力科学研究院 | A kind of appraisal procedure of multi-infeed HVDC system DC support ability and commutation failure |
| CN110441658A (en) * | 2019-08-27 | 2019-11-12 | 国网新疆电力有限公司经济技术研究院 | A kind of high voltage direct current commutation failure method of discrimination considering DC current variation |
| CN111007360A (en) * | 2019-12-27 | 2020-04-14 | 新疆大学 | Extra-high voltage direct current transmission system commutation failure judgment method considering current change |
Non-Patent Citations (2)
| Title |
|---|
| 汤奕 等: ""抑制连续换相失败的直流功率控制策略"", 《电网技术》 * |
| 王璐 等: ""考虑直流电流变化的HVDC系统不对称故障换相失败分析"", 《电力系统保护与控制》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113484578A (en) * | 2021-07-14 | 2021-10-08 | 南方电网科学研究院有限责任公司 | Commutation state detection method, device and equipment of high-voltage direct current system |
| CN113484578B (en) * | 2021-07-14 | 2024-01-23 | 南方电网科学研究院有限责任公司 | Commutation state detection method, device and equipment for high-voltage direct-current system |
| CN113433426A (en) * | 2021-08-30 | 2021-09-24 | 国网江西省电力有限公司电力科学研究院 | Method and device for calculating critical fault position of converter bus of direct-current transmission system |
| CN113433426B (en) * | 2021-08-30 | 2021-12-31 | 国网江西省电力有限公司电力科学研究院 | Method and device for calculating critical fault position of converter bus of direct-current transmission system |
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