CN108879752A - A kind of parameter optimization method based on current limiting low-voltage link - Google Patents
A kind of parameter optimization method based on current limiting low-voltage link Download PDFInfo
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- CN108879752A CN108879752A CN201810769012.9A CN201810769012A CN108879752A CN 108879752 A CN108879752 A CN 108879752A CN 201810769012 A CN201810769012 A CN 201810769012A CN 108879752 A CN108879752 A CN 108879752A
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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]
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Abstract
The invention discloses a kind of parameter optimization methods based on low pressure switch-over unit, include the following steps：Voltage limitation under normal operating conditions remains as rectification side (0.1,0.7), inverter side (0.15,0.8)；It should judge whether to enter parameter optimization program according to receiving end alternating voltage situation of change after failure；This four inverter side alternating voltage, current reference value, actual current, the effective short-circuit ratio ESCR of system amounts are introduced as variable is calculated, calculate the UD_HIGH_INV of Inverter Station；By UD_HIGH_INV to wait slope ratios principle that UD_HIGH_REC is calculated；The voltage-current curve expression formula of rectification side and inverter side is calculated；Formula and actual DC voltage measuring value are expressed according to voltage and current, obtains DC current upper limit value, completes the control in system recovery procedure to system.The present invention can effectively avoid the generation of thread-changing failure in failover procedure under receiving end weak AC system, improve the stability of ac and dc systems operation.
Description
Technical field
The invention belongs to the control technology fields of Operation of Electric Systems, and in particular to a kind of ginseng based on voltage current limit link
Number optimization method.
Background technique
Direct current receiving end accesses weak pattern system, and the single-phase transient earthing of inverter side AC system occurs for the biggish operating condition of transmission power
After failure, in system recovery procedure, direct current is risen rapidly, and weak receiving end alternating voltage may be caused to decline, cause to occur again
Commutation failure.In response to this, the recovery situation of direct current system can be improved by optimizing the parameter of current limiting low-voltage link,
Avoid the generation of subsequent thread-changing failure.But if using a set of fixation current limiting low-voltage parameter, although can be to a certain extent
Inhibit the generation of subsequent commutation failure, but will affect steady state operating condition.Therefore consider from two side of Steady-state Parameters and transient state parameter
Face all carries out related optimization.
Current-order final output value is determined by current limiting low-voltage link, and wherein the upper limit of DC voltage determines that electric current refers to
The upper limit value of order.Upper voltage limit is too high, and virtual voltage slightly declines the decline that will result in current-order；Upper voltage limit is too low,
Electric current rises meeting quickly in voltage recovery process after a failure, larger to the impact of system.At present in fortune DC engineering low pressure limit
Flow the upper voltage limit that generally uses for：Rectification side (0.1,0.7), inverter side (0.15,0.8), two of them station current-order
The difference of an about 0.1pu can be retained always, realize current margins control.
AC system stronger for receiving end power grid, this set parameter have general applicability, but when receiving end power grid is very weak
When, quickly biggish impact is caused to AC system, it is possible to cause receiving end voltage abnormal in recovery process after DC system fault
Become and commutation failure even occurs, the stable operation of ac and dc systems is caused to seriously affect.If according to the intensity of receiving end power grid
And malfunction, the upper voltage limit of current limiting low-voltage link is accordingly optimized, control DC current instruction, it is possible to keep away
Exempt from the generation of commutation failure.
Summary of the invention
Goal of the invention：For the inherent limitation of above-mentioned existing current limiting low-voltage link parameter setting, the present invention provides one kind
Parameter optimization method based on current limiting low-voltage link.
Technical solution：For achieving the above object, the technical solution adopted by the present invention is a kind of based on current limiting low-voltage ring
The parameter optimization method of section, includes the following steps：
The parameter objectives of optimization are two station current limiting low-voltage link voltage upper limit values：UD_HIGH_REC and UD_HIGH_
INV。
(1) voltage limitation remains as rectification side (0.1,0.7) under normal operating conditions, inverter side (0.15,0.8)；
(2) should judge whether to enter parameter optimization program according to receiving end alternating voltage situation of change after failure；
(3) this four inverter side alternating voltage, current reference value, actual current, the effective short-circuit ratio ESCR of system amounts are introduced
As variable is calculated, the UD_HIGH_INV of Inverter Station is calculated；
(4) by UD_HIGH_INV to wait slope ratios principle that UD_HIGH_REC is calculated；
(5) the voltage-current curve expression formula of rectification side and inverter side is calculated；
(6) formula and actual DC voltage measuring value are expressed according to voltage and current, obtains DC current upper limit value I_ORD_
LIM completes the control in system recovery procedure to system.
Beneficial effect：Current limiting low-voltage link parameter is one of the important parameter for guaranteeing ac and dc systems stable operation, is needed
Accordingly optimized according to access system condition and malfunction.It is proposed by the present invention with DC current reference value, actual current,
The calculating side of effective short-circuit ratio, commutation voltage distortion parameter as design conditions optimization current limiting low-voltage link DC voltage upper limit value
Method avoids the subsequent commutation failure in direct current recovery process to friendship to improve the recovery characteristics after DC transmission system failure
The disturbance of galvanic electricity pressure and frequency.It is calculated according to actual emulation：According to inverter side AC system voltage distortion situation, two are calculated in real time
The upper voltage limit of side current limiting low-voltage function can effectively avoid receiving end weak AC system feelings to inhibit the DC current rate of climb
Under condition in failover procedure commutation failure generation, improve the operation stability of ac and dc systems.
Detailed description of the invention
Fig. 1 is the method for the present invention flow chart；
Fig. 2 is the voltage and current external characteristic curve of the current limiting low-voltage link after optimization；
Fig. 3 is AC_DIP_ON decision logic figure；
Fig. 4 is to take before optimization method converting plant DC voltage, direct current under the single wink failure in Inverter Station change of current bus proximal end
Stream and triggering angular curve；
Fig. 5 is to take after optimization method converting plant DC voltage, direct current under the single wink failure in Inverter Station change of current bus proximal end
Stream and triggering angular curve.
Specific embodiment
Combined with specific embodiments below to further detailed description of the invention.
Fig. 2 is the optimum results curve finally realized, wherein bold curve indicates rectification side, and thin curve is inverter side；It is real
Line indicates that current limiting low-voltage link original parameter, dotted line indicate current limiting low-voltage node optimization parameter under failure.
Particular content is as follows：
(1) according to DC current upper lower limit value (0.345,1.0) and voltage upper lower limit value, when obtaining two stations normal operations
The expression formula of DC voltage and electric current：
I=1.0920U+0.2358 (1)
I=1.0077U+0.1938 (2)
Formula (1) is converting plant expression formula, and formula (2) is Inverter Station expression formula.
(2) according at present in the Control protection system of fortune DC engineering, introducing UAC_MIN_HOLDAmount is that converter power transformer is star-like
The minimum value of three line voltage maximum absolute value values is surveyed with the net of delta windings.For this value by calculating, change rate is more than limit
After degree, AC_DIP_ON signal becomes 1, starts current limiting low-voltage node optimization program.
Wherein, Ua、Ub、UcRespectively change of current bus three-phase phase voltage, is obtained by calculation UAC_MIN_HOLDAmount, passes through with it
The result that the filtering link of one large time constant obtains is divided by, and obtains working as UAC_MIN_HOLDAC_DIP_ON when temporal variations.
(3) inverter side alternating voltage calculation amount U is introducedAC_MIN_HOLD, current reference value, actual current, system short-circuit ratio SCR
This four amounts calculate the UD_HIGH_INV of Inverter Station as variable is calculated.Wherein, UAC_MIN_HOLDIt is inverse ratio with UD_HIGH_INV
The difference and UD_HIGH_INV of relationship, current reference value and actual current are proportional relation, system short-circuit ratio SCR and UD_
HIGH_INV is inverse relation, and the calculating formula for finally obtaining UD_HIGH_INV is as follows：
Wherein U 'INVFor the optimization UD_HIGH_INV, U being calculatedINVFor stable state UD_HIGH_INV, value 0.8,
IrefFor current reference value, IdFor actual DC electric current, UminFor UAC_MIN_HOLD, k is adjustable proportionality coefficient.
(4) the inverter side voltage-current curve after having been optimized at present, according to slope equal proportion principle, after calculation optimization
Rectification side voltage-current curve slope.Slope equal proportion calculating formula is：
Enabling rectification side voltage-current curve slope after optimization is k 'REC, then：
Rectification side voltage-current curve mathematical expression is after order optimization：
I=k 'REC·U+a (6)
Wherein a brings formula into according to rectification side voltage-current curve after optimization there are point (0.1,0.345) for algebra constant
(6) it obtains：
A=0.345-0.1 × k 'REC (7)
U ' is obtained according to formula (4)RECWith U 'INVRelational expression be：
(5) finally obtaining rectification side voltage-current curve expression formula according to formula (6)-(8) is：
Inverter side voltage-current curve expression formula is after order optimization：
I=k 'INV·U+b (10)
Wherein b brings formula into according to rectification side voltage-current curve after optimization there are point (0.15,0.345) for constant to be asked
(10) it obtains：
Formula (11) is updated to formula (10) and obtains inverter side voltage-current curve expression formula：
(6) formula (9) and formula (12) finally obtained by the above calculating process is respectively rectification side and inverter side voltage and current
Curve representation formula, the actual DC voltage for obtaining and handling according to measurement in program, can be calculated current limit I_ORD_
LIM。
Actual emulation experiment：The control of direct current system bipolar power, transmission power 3000MW, Inverter Station exchange outlet proximal end hair
Raw single-phase transient fault, duration 80ms.
It is from top to bottom respectively converting plant DC voltage, DC current and Trigger Angle in Fig. 4.As shown in Figure 4, in exchange event
After barrier restores, 4 commutation failures are had occurred in direct current system in recovery process.
It is accordingly modified to the software program in practical control protective unit, is then carried out under identical operating condition again
Actual emulation experiment, as shown in Figure 5.It is from top to bottom respectively converting plant DC voltage, DC current, Trigger Angle and low in Fig. 5
Press current limit link DC voltage upper limit value.As seen from Figure 5, according to inverter side AC system voltage distortion situation, two are calculated in real time
The upper voltage limit of side current limiting low-voltage function can effectively avoid receiving end weak AC system feelings to inhibit the DC current rate of climb
Under condition in failover procedure commutation failure generation, improve ac and dc systems operation stability.
Claims (1)
1. a kind of parameter optimization method based on current limiting low-voltage link, includes the following steps：
(1) voltage limitation remains as rectification side (0.1,0.7) under normal operating conditions, inverter side (0.15,0.8)；
(2) should judge whether to enter parameter optimization program according to receiving end alternating voltage situation of change after failure；
(3) inverter side alternating voltage, current reference value, this four actual current, the effective short-circuit ratio ESCR of system amount conducts are introduced
Variable is calculated, the UD_HIGH_INV of Inverter Station is calculated；
(4) by UD_HIGH_INV to wait slope ratios principle that UD_HIGH_REC is calculated；
(5) the voltage-current curve expression formula of rectification side and inverter side is calculated；
(6) formula and actual DC voltage measuring value are expressed according to voltage and current, obtains DC current upper limit value, completed system and restore
In the process to the control of system.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110233490A (en) * | 2019-07-05 | 2019-09-13 | 重庆城市管理职业学院 | Avoid the direct current transportation fault recovery control method and system of continuous commutation failure |
| CN110994641A (en) * | 2019-11-13 | 2020-04-10 | 中国电力科学研究院有限公司 | Method for inhibiting large-amplitude power oscillation of direct-current transmission project |
-
2018
- 2018-07-13 CN CN201810769012.9A patent/CN108879752A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110233490A (en) * | 2019-07-05 | 2019-09-13 | 重庆城市管理职业学院 | Avoid the direct current transportation fault recovery control method and system of continuous commutation failure |
| CN110233490B (en) * | 2019-07-05 | 2020-11-10 | 重庆城市管理职业学院 | Direct-current transmission fault recovery control method and system for avoiding continuous commutation failure |
| CN110994641A (en) * | 2019-11-13 | 2020-04-10 | 中国电力科学研究院有限公司 | Method for inhibiting large-amplitude power oscillation of direct-current transmission project |
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Application publication date: 20181123 |