CN112217237A - Active damping control method for direct-drive wind power grid-connected system under asymmetric fault - Google Patents

Active damping control method for direct-drive wind power grid-connected system under asymmetric fault Download PDF

Info

Publication number
CN112217237A
CN112217237A CN202011149760.0A CN202011149760A CN112217237A CN 112217237 A CN112217237 A CN 112217237A CN 202011149760 A CN202011149760 A CN 202011149760A CN 112217237 A CN112217237 A CN 112217237A
Authority
CN
China
Prior art keywords
power grid
positive
direct
wind power
drive wind
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202011149760.0A
Other languages
Chinese (zh)
Other versions
CN112217237B (en
Inventor
于海
徐贵
张瑞强
姚骏
郝文海
陈诗玥
原帅
黄森
韩硕
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baotou Power Supply Bureau Of Inner Mongolia Power Group Co ltd
Chongqing University
Original Assignee
Baotou Power Supply Bureau Of Inner Mongolia Power Group Co ltd
Chongqing University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Baotou Power Supply Bureau Of Inner Mongolia Power Group Co ltd, Chongqing University filed Critical Baotou Power Supply Bureau Of Inner Mongolia Power Group Co ltd
Priority to CN202011149760.0A priority Critical patent/CN112217237B/en
Publication of CN112217237A publication Critical patent/CN112217237A/en
Application granted granted Critical
Publication of CN112217237B publication Critical patent/CN112217237B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • 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
    • H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
    • 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
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • 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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/76—Power conversion electric or electronic aspects
    • 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
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/40—Arrangements for reducing harmonics

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

The invention discloses an active damping control method of a direct-drive wind power grid-connected system under an asymmetric fault, which is used for improving the dynamic stability of the direct-drive wind power grid-connected system during the asymmetric short-circuit fault of a power grid; the method considers the interaction between the positive and negative sequence current loops of the grid-side converter of the direct-drive wind power grid-connected system and the grid impedance under the asymmetric fault of the grid, introduces active damping through the high-pass filter and the virtual resistor to inhibit the positive and negative sequence harmonic current of the grid, and improves the dynamic stability of the system. On the basis of not changing parameters and structures of an internal controller, the dynamic stability of the direct-drive wind power grid-connected system under the asymmetric fault of the power grid can be obviously improved only by adding the high-pass filter and introducing the virtual impedance.

Description

Active damping control method for direct-drive wind power grid-connected system under asymmetric fault
Technical Field
The invention relates to an improved active damping control method for a direct-drive wind power grid-connected system, which is suitable for a direct-drive wind power grid-connected system grid-side converter under an asymmetric fault of an alternating current power grid.
Background
With the gradual increase of the permeability of new energy power generation in a power system, a power grid has the characteristics of low inertia, weak synchronization and the like. In addition, a large wind power plant is usually connected to a power grid through a long transmission line and a high impedance, when a short-circuit fault occurs in the power grid, interaction between output current of a direct-drive wind power grid-connected system and line impedance is intensified, dynamic stability of the system during low-voltage ride-through is deteriorated, even large-interference instability of the system is caused, and low-voltage ride-through cannot be successfully realized. Considering that asymmetric faults are most common in power grid faults, the dynamic stability problem of the direct-drive wind power grid-connected system under the condition of the asymmetric faults of the power grid is more severe. Therefore, the capability of safe and stable operation of the power grid can be effectively improved by improving the dynamic stability of the direct-drive wind power grid-connected system under the asymmetric short-circuit fault. Relevant studies have been carried out by scholars at home and abroad, such as the following published documents:
[1]Yipeng Song,Xiongfei Wang,Frede Blaabjerg.High Frequency Resonance Damping of DFIG based Wind Power System under Weak Network[J].IEEE Trans.Power Electron.2017,32(3):1927–1940.
[2]Jintao Guo,Tao Jin,Mengqi Wang.A coordinated controlling strategy in current and power quality for grid-connected inverter under unbalanced grid voltage[C].2019IEEE Sustainable Power and Energy Conference(iSPEC).IEEE,2019:1183-1188.
document [1] proposes damping control based on virtual positive capacitance or virtual negative inductance, and the damping control is added to a current control loop to suppress harmonic current so as to improve the dynamic stability of the new energy grid-connected inverter, but the active damping control method depends on accurate resonance frequency detection, does not consider a control strategy of a negative sequence current control loop in an asymmetric fault scene, and cannot be applied in the asymmetric fault scene. Document [2] proposes a flexible control strategy to suppress power oscillation and current harmonics of the grid-connected inverter under the asymmetric grid fault, but the document ignores the influence of PLL dynamics on system stability under the asymmetric grid fault condition, and actually, as the grid impedance increases, the interaction between the PLL and the current control loop increases, further deteriorating the small signal stability of the grid-connected inverter under the grid fault.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an active damping control method of a direct-drive wind power grid-connected system under an asymmetric short-circuit fault.
The technical scheme of the invention is realized as follows:
an active damping control method of a direct-drive wind power grid-connected system under an asymmetric fault is used for improving the dynamic stability of the direct-drive wind power grid-connected system during an asymmetric short-circuit fault of a power grid; the method considers the interaction between the positive and negative sequence current loops of the grid-side converter of the direct-drive wind power grid-connected system and the grid impedance under the asymmetric fault of the grid, introduces active damping through the high-pass filter and the virtual resistor to inhibit the positive and negative sequence harmonic current of the grid, and improves the dynamic stability of the system.
The method comprises the following specific steps;
A1) during the asymmetrical fault of the power grid, a direct-drive wind power grid-connected system grid-side converter adopts a positive sequence current control loop and a negative sequence current control loop, and positive sequence control voltage V and negative sequence control voltage V are calculated according to the following formuladq+And Vdq-：
Figure BDA0002740813500000021
In the formula (I), the compound is shown in the specification,
Figure BDA0002740813500000022
is a positive sequence current reference value under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric fault,
Figure BDA0002740813500000023
is a negative sequence current reference value I under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric faultdq+And Idq-Inputting three-phase current through positive and negative sequence current k of coordinate transformation for collected direct-drive wind power grid-connected systemp1And ki1Proportional and integral coefficients, K, of the current loop PI controller, respectivelydqIs a coupling coefficient, s is a differential operator;
A2) on the basis of the step A1), the positive sequence current I is converted into the negative sequence current Idq+And negative sequence current Idq-Obtaining positive and negative sequence harmonic currents through a high-pass filter, amplifying the positive and negative sequence harmonic currents through a virtual resistor, respectively feeding forward to positive and negative sequence control voltages of a grid-side converter, restraining output current harmonics of a direct-drive wind power grid-connected system, and feeding forward the positive and negative sequence control voltages V after compensationdq+_reAnd Vdq-_reThe following formula is satisfied:
Figure BDA0002740813500000024
in the formula, ZvIs a virtual impedance to achieve active damping;
A3) virtual impedance ZvIs composed of a virtual resistor and a high-pass filter according to the following formulaAnd (3) calculating:
Zv(s)＝Rv·Hfilter(s)
in the formula RvIs a virtual resistance; hfilter(s) is the high pass filter transfer function, Hfilter(s)＝s/(s+2πfcut) (ii) a s is a differential operator, fcutIs the cut-off frequency of the high-pass filter;
A4) step A2) and step A3) apply a virtual impedance ZvAfter a direct-drive wind power grid-connected system is introduced, positive and negative sequence remodeling impedance Z of a grid-side converter of the direct-drive wind power grid-connected systemvsc_reThe following formula is satisfied:
Figure BDA0002740813500000031
the active damping control of the direct-drive wind power grid-connected system during the asymmetric fault can be realized, so that the dynamic stability of the system during the asymmetric fault is improved; in the formula Vvsc_re,pnPositive and negative sequence voltage, I, of grid-connected point of direct-drive wind power grid-connected systemvsc_re,pnOutputting positive and negative sequence current for a direct-drive wind power grid-connected system; the remodelling impedance satisfies the following equation:
Figure BDA0002740813500000032
wherein, each element of the remolding impedance matrix is respectively:
Figure BDA0002740813500000033
Figure BDA0002740813500000034
Figure BDA0002740813500000035
Figure BDA0002740813500000041
Figure BDA0002740813500000042
Figure BDA0002740813500000043
Figure BDA0002740813500000044
Figure BDA0002740813500000045
wherein the content of the first and second substances,
Figure BDA0002740813500000046
Figure BDA0002740813500000047
Figure BDA0002740813500000048
N(s)＝HPLL(s)HPLL(s±j4πf1)；La、Lb、Lceach is ABC three-phase line inductance, and alpha is operator alpha ═ ej2/3π，I1、I2Respectively a positive-sequence fundamental frequency current component and a negative-sequence fundamental frequency current component of the power grid, I1'、I2' Positive-sequence fundamental current conjugate and negative-sequence fundamental current conjugate, V, respectively1、V2A positive-sequence fundamental frequency voltage component and a negative-sequence fundamental frequency voltage component, V, of a grid-connected point respectively1' and V2' Positive-sequence fundamental frequency voltage conjugation and negative-sequence fundamental frequency voltage conjugation, respectively, f1Is electricityThe frequency of the fundamental wave of the network,
Figure BDA0002740813500000049
and
Figure BDA00027408135000000410
the primary phase angles of the positive sequence fundamental frequency current and the negative sequence fundamental frequency current of the power grid are respectively; hi(s)＝kp1+ki1/s，kp1And ki1Respectively is a proportional coefficient and an integral coefficient of the current loop PI controller;
Figure BDA00027408135000000411
kppand kpiProportional and integral coefficients, omega, of the phase-locked loop, respectively1At angular frequency of fundamental frequency, zeta is damping ratio, omeganIs the natural oscillation angular frequency; s is the differential operator and j is the imaginary unit.
According to the active damping control method of the direct-drive wind power grid-connected system under the asymmetric short-circuit fault, the dynamic stability of the direct-drive wind power grid-connected system under the asymmetric fault of a power grid can be obviously improved only by introducing the virtual impedance based on the addition of the high-pass filter on the basis of not changing the parameters and the structure of an internal controller. The method can inhibit the current harmonic wave of the direct-drive grid-connected system during the asymmetrical short-circuit fault of the power grid, thereby improving the small signal stability of the system.
Drawings
FIG. 1 is a schematic diagram of a direct-drive wind power grid-connected system structure.
Fig. 2 is a schematic diagram of an active damping control method according to the present invention.
Fig. 3 is a simulation waveform diagram before and after the active damping control strategy provided by the invention is adopted when the two-phase short circuit ground fault occurs in the power grid, the positive sequence voltage of the power grid drops to 52% and 62% respectively, and the voltage unbalance coefficients are 61% and 45%.
Detailed Description
The following detailed description of specific embodiments of the invention refers to the accompanying drawings.
The method is used for improving the small signal stability of the direct-drive wind power grid-connected system under the power grid asymmetric short-circuit fault. Fig. 1 is a schematic diagram of a direct-drive wind power grid-connected system structure, and fig. 2 is a schematic diagram of an active damping control method provided by the invention. During the asymmetrical short circuit fault of the power grid, the suppression of the positive and negative sequence harmonic waves of the output current of the direct-drive wind power grid-connected system can be realized by adopting an active damping control strategy, so that the small signal stability of the direct-drive wind power grid-connected system is improved.
The method comprises the following specific implementation steps:
A1) during the asymmetrical fault of the power grid, a direct-drive wind power grid-connected system grid-side converter adopts a positive sequence current control loop and a negative sequence current control loop, and positive sequence control voltage V and negative sequence control voltage V are calculated according to the following formuladq+And Vdq-：
Figure BDA0002740813500000051
In the formula (I), the compound is shown in the specification,
Figure BDA0002740813500000052
is a positive sequence current reference value under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric fault,
Figure BDA0002740813500000053
is a negative sequence current reference value I under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric faultdq+And Idq-Inputting three-phase current through positive and negative sequence current k of coordinate transformation for collected direct-drive wind power grid-connected systemp1And ki1Proportional and integral coefficients, K, of the current loop PI controller, respectivelydqIs a coupling coefficient, s is a differential operator;
A2) on the basis of the step A1), the positive sequence current I is converted into the negative sequence current Idq+And negative sequence current Idq-Obtaining positive and negative sequence harmonic currents through a high-pass filter, amplifying the positive and negative sequence harmonic currents through a virtual resistor, respectively feeding forward to positive and negative sequence control voltages of a grid-side converter, restraining output current harmonics of a direct-drive wind power grid-connected system, and feeding forward the positive and negative sequence control voltages V after compensationdq+_reAnd Vdq-_reThe following formula is satisfied:
Figure BDA0002740813500000054
in the formula, ZvIs a virtual impedance to achieve active damping;
A3) virtual impedance ZvThe circuit consists of a virtual resistor and a high-pass filter, and is calculated according to the following formula:
Zv(s)＝Rv·Hfilter(s)
in the formula RvIs a virtual resistance; hfilter(s) is the high pass filter transfer function, Hfilter(s)＝s/(s+2πfcut) (ii) a s is a differential operator, fcutIs the cut-off frequency of the high-pass filter;
A4) step A2) and step A3) apply a virtual impedance ZvAfter a direct-drive wind power grid-connected system is introduced, positive and negative sequence remodeling impedance Z of a grid-side converter of the direct-drive wind power grid-connected systemvsc_reThe following formula is satisfied:
Figure BDA0002740813500000061
the active damping control of the direct-drive wind power grid-connected system during the asymmetric fault can be realized, so that the dynamic stability of the system during the asymmetric fault is improved; in the formula Vvsc_re,pnPositive and negative sequence voltage, I, of grid-connected point of direct-drive wind power grid-connected systemvsc_re,pnOutputting positive and negative sequence current for a direct-drive wind power grid-connected system; the remodelling impedance satisfies the following equation:
Figure BDA0002740813500000062
wherein, each element of the remolding impedance matrix is respectively:
Figure BDA0002740813500000063
Figure BDA0002740813500000064
Figure BDA0002740813500000065
;
Figure BDA0002740813500000072
Figure BDA0002740813500000073
Figure BDA0002740813500000074
Figure BDA0002740813500000075
Figure BDA0002740813500000076
wherein the content of the first and second substances,
Figure BDA0002740813500000077
Figure BDA0002740813500000078
Figure BDA0002740813500000079
N(s)＝HPLL(s)HPLL(s±j4πf1)；La、Lb、Lcrespectively ABC three-phase line inductance, alpha is an operatorα＝ej2/3π，I1、I2Respectively a positive-sequence fundamental frequency current component and a negative-sequence fundamental frequency current component of the power grid, I1'、I2' Positive-sequence fundamental current conjugate and negative-sequence fundamental current conjugate, V, respectively1、V2A positive-sequence fundamental frequency voltage component and a negative-sequence fundamental frequency voltage component, V, of a grid-connected point respectively1' and V2' Positive-sequence fundamental frequency voltage conjugation and negative-sequence fundamental frequency voltage conjugation, respectively, f1Is the frequency of the fundamental wave of the power grid,
Figure BDA00027408135000000710
and
Figure BDA00027408135000000711
the primary phase angles of the positive sequence fundamental frequency current and the negative sequence fundamental frequency current of the power grid are respectively; hi(s)＝kp1+ki1/s，kp1And ki1Respectively is a proportional coefficient and an integral coefficient of the current loop PI controller;
Figure BDA00027408135000000712
kppand kpiProportional and integral coefficients, omega, of the phase-locked loop, respectively1At angular frequency of fundamental frequency, zeta is damping ratio, omeganIs the natural oscillation angular frequency; s is the differential operator and j is the imaginary unit.
Description of the effects of the invention:
fig. 3 shows simulation waveforms before and after the active damping control strategy provided by the present invention is adopted when the positive sequence voltage of the power grid drops to 52% and 62%, respectively, and the voltage unbalance coefficients are 61% and 45%. The short-circuit ratio of the power grid is 2.3, two-phase short-circuit grounding faults occur in the power grid at the moment of 1.5s, the positive sequence voltage of the power grid falls to 52% of the rated voltage, the voltage unbalance coefficient is 61%, and t is t1The grid-side converter of the direct-drive wind power grid-connected system in the (1.5s-1.8s) stage is controlled only by adopting basic positive and negative sequence current loops, and active damping control provided by the invention is not adopted, so that the voltage V of the public connection point of the power grid can be seenPCCThe positive sequence current and the negative sequence current of the power grid contain a large amount of harmonic waves and have obvious oscillation; t is t2In the (1.8s-2.1s) stage, the invention proposesSource damping control, output positive and negative sequence current and common connection point voltage VpccIs significantly suppressed; t is t3In the (2.1s-2.4s) stage, the positive sequence voltage of the power grid rises to 62%, the voltage unbalance coefficient becomes 45%, and by adopting the active damping control strategy provided by the invention, the active damping control strategy provided by the invention can be clearly seen to effectively inhibit the oscillation problem caused by the asymmetrical short circuit fault of the power grid, and has good adaptability when the voltage shock and the voltage unbalance degree change.
Therefore, the active damping control strategy of the direct-drive wind power grid-connected system provided by the invention can obviously improve the dynamic stability of the direct-drive wind power grid-connected system under the asymmetric fault of the power grid and improve the safe and stable operation capability of the power grid.
Finally, it should be noted that the above-mentioned examples of the present invention are only examples for illustrating the present invention, and are not intended to limit the embodiments of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it will be apparent to those skilled in the art that other variations and modifications can be made based on the above description. Not all embodiments are exhaustive. All obvious changes and modifications of the present invention are within the scope of the present invention.

Claims (1)

1. An active damping control method of a direct-drive wind power grid-connected system under an asymmetric fault is used for improving the dynamic stability of the direct-drive wind power grid-connected system during an asymmetric short-circuit fault of a power grid; the method is characterized in that: the method considers the interaction between the positive and negative sequence current loops of the direct-drive wind power grid-connected system grid-side converter and the grid impedance under the power grid asymmetric fault, introduces active damping through a high-pass filter and a virtual resistor to inhibit the positive and negative sequence harmonic current of the power grid, and improves the dynamic stability of the system; the method comprises the following specific steps;
A1) during the asymmetrical fault of the power grid, a direct-drive wind power grid-connected system grid-side converter adopts a positive sequence current control loop and a negative sequence current control loop, and positive sequence control voltage V and negative sequence control voltage V are calculated according to the following formuladq+And Vdq-：
Figure FDA0002740813490000011
In the formula (I), the compound is shown in the specification,
Figure FDA0002740813490000012
is a positive sequence current reference value under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric fault,
Figure FDA0002740813490000013
is a negative sequence current reference value I under a synchronous rotating coordinate system input to a power grid by a direct-drive wind power grid-connected system during an asymmetric faultdq+And Idq-Inputting three-phase current through positive and negative sequence current k of coordinate transformation for collected direct-drive wind power grid-connected systemp1And ki1Proportional and integral coefficients, K, of the current loop PI controller, respectivelydqIs a coupling coefficient, s is a differential operator;
A2) on the basis of step A1), Idq+And Idq-Obtaining positive and negative sequence harmonic currents through a high-pass filter, amplifying the positive and negative sequence harmonic currents through a virtual resistor, respectively feeding forward to positive and negative sequence control voltages of a grid-side converter, restraining output current harmonics of a direct-drive wind power grid-connected system, and feeding forward the positive and negative sequence control voltages V after compensationdq+_reAnd Vdq-_reThe following formula is satisfied:
Figure FDA0002740813490000014
in the formula, ZvIs a virtual impedance to achieve active damping;
A3) virtual impedance ZvThe circuit consists of a virtual resistor and a high-pass filter, and is calculated according to the following formula:
Zv(s)＝Rv·Hfilter(s)
in the formula RvIs a virtual resistance; hfilter(s) isHigh pass filter transfer function, Hfilter(s)＝s/(s+2πfcut) (ii) a s is a differential operator, fcutIs the cut-off frequency of the high-pass filter;
A4) step A2) and step A3) apply a virtual impedance ZvAfter a direct-drive wind power grid-connected system is introduced, positive and negative sequence remodeling impedance Z of a grid-side converter of the direct-drive wind power grid-connected systemvsc_reThe following formula is satisfied:
Figure FDA0002740813490000015
the active damping control of the direct-drive wind power grid-connected system during the asymmetric fault can be realized, so that the dynamic stability of the system during the asymmetric fault is improved; in the formula Vvsc_re,pnPositive and negative sequence voltage, I, of grid-connected point of direct-drive wind power grid-connected systemvsc_re,pnOutputting positive and negative sequence current for a direct-drive wind power grid-connected system; the remodelling impedance satisfies the following equation:
Figure FDA0002740813490000021
wherein, each element of the remolding impedance matrix is respectively:
Figure FDA0002740813490000022
Figure FDA0002740813490000023
Figure FDA0002740813490000024
Figure FDA0002740813490000025
Figure FDA0002740813490000026
Figure FDA0002740813490000031
Figure FDA0002740813490000032
Figure FDA0002740813490000033
wherein the content of the first and second substances,
Figure FDA0002740813490000034
Figure FDA0002740813490000035
Figure FDA0002740813490000037
N(s)＝HPLL(s)HPLL(s±j4πf1)；La、Lb、Lceach is ABC three-phase line inductance, and alpha is operator alpha ═ ej2/3π，I1、I2Respectively a positive-sequence fundamental frequency current component and a negative-sequence fundamental frequency current component, I'1、I′2Respectively positive-sequence fundamental frequency current conjugate and negative-sequence fundamental frequency current conjugate, V1、V2Are a grid-connected point positive-sequence fundamental frequency voltage component and a negative-sequence fundamental frequency voltage component, V'1And V'2Positive sequence fundamental frequency voltage conjugation and negative sequence fundamental frequency voltage conjugation respectively，f1Is the frequency of the fundamental wave of the power grid,
Figure FDA0002740813490000038
and
Figure FDA0002740813490000039
the primary phase angles of the positive sequence fundamental frequency current and the negative sequence fundamental frequency current of the power grid are respectively; hi(s)＝kp1+ki1/s，kp1And ki1Respectively is a proportional coefficient and an integral coefficient of the current loop PI controller;
Figure FDA0002740813490000036
kppand kpiProportional and integral coefficients, omega, of the phase-locked loop, respectively1At angular frequency of fundamental frequency, zeta is damping ratio, omeganIs the natural oscillation angular frequency; s is the differential operator and j is the imaginary unit.
CN202011149760.0A 2020-10-23 2020-10-23 Active damping control method for direct-driven wind power grid-connected system under asymmetric fault Active CN112217237B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011149760.0A CN112217237B (en) 2020-10-23 2020-10-23 Active damping control method for direct-driven wind power grid-connected system under asymmetric fault

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011149760.0A CN112217237B (en) 2020-10-23 2020-10-23 Active damping control method for direct-driven wind power grid-connected system under asymmetric fault

Publications (2)

Publication Number Publication Date
CN112217237A true CN112217237A (en) 2021-01-12
CN112217237B CN112217237B (en) 2024-01-26

Family

ID=74055114

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011149760.0A Active CN112217237B (en) 2020-10-23 2020-10-23 Active damping control method for direct-driven wind power grid-connected system under asymmetric fault

Country Status (1)

Country Link
CN (1) CN112217237B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113162120A (en) * 2021-05-31 2021-07-23 重庆大学 Wind power grid-connected system transient stability control method based on automatic virtual resistance compensation
CN113904373A (en) * 2021-11-03 2022-01-07 重庆大学 Stability enhancement control method for grid-connected converter under different output working conditions
CN115207912A (en) * 2022-07-27 2022-10-18 重庆大学 Small signal stability enhancement control strategy for grid-connected converter under weak grid asymmetric voltage drop fault
CN115954927A (en) * 2022-09-23 2023-04-11 中国华能集团清洁能源技术研究院有限公司 Method and system for determining transient synchronous stability coefficient of phase-locked synchronous grid-connected converter

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108092302A (en) * 2017-11-20 2018-05-29 东南大学 Load virtual synchronous machine low voltage traversing control method
US20190190276A1 (en) * 2017-12-15 2019-06-20 Delta Electronics (Shanghai) Co., Ltd Method and device for controlling distribution of unbalanced and harmonic power among parallel inverters
CN111130142A (en) * 2020-01-19 2020-05-08 重庆大学 Virtual capacitance control method for double-fed wind power generation grid-connected system
US20200287410A1 (en) * 2017-12-28 2020-09-10 Beijing Etechwin Electric Co., Ltd. Microgrid control system and microgrid

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108092302A (en) * 2017-11-20 2018-05-29 东南大学 Load virtual synchronous machine low voltage traversing control method
US20190190276A1 (en) * 2017-12-15 2019-06-20 Delta Electronics (Shanghai) Co., Ltd Method and device for controlling distribution of unbalanced and harmonic power among parallel inverters
US20200287410A1 (en) * 2017-12-28 2020-09-10 Beijing Etechwin Electric Co., Ltd. Microgrid control system and microgrid
CN111130142A (en) * 2020-01-19 2020-05-08 重庆大学 Virtual capacitance control method for double-fed wind power generation grid-connected system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
黄守道;肖磊;黄科元;陈自强;熊山: "不对称电网故障下直驱型永磁风力发电***网侧变流器的运行与控制", 电工技术学报, vol. 26, no. 2 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113162120A (en) * 2021-05-31 2021-07-23 重庆大学 Wind power grid-connected system transient stability control method based on automatic virtual resistance compensation
CN113162120B (en) * 2021-05-31 2022-11-01 重庆大学 Wind power grid-connected system transient stability control method based on automatic virtual resistance compensation
CN113904373A (en) * 2021-11-03 2022-01-07 重庆大学 Stability enhancement control method for grid-connected converter under different output working conditions
CN113904373B (en) * 2021-11-03 2024-04-09 重庆大学 Stability enhancement control method for grid-connected converter under different output working conditions
CN115207912A (en) * 2022-07-27 2022-10-18 重庆大学 Small signal stability enhancement control strategy for grid-connected converter under weak grid asymmetric voltage drop fault
CN115207912B (en) * 2022-07-27 2024-03-29 重庆大学 Small signal stability enhancement control strategy for grid-connected converter under asymmetric voltage drop fault of weak power grid
CN115954927A (en) * 2022-09-23 2023-04-11 中国华能集团清洁能源技术研究院有限公司 Method and system for determining transient synchronous stability coefficient of phase-locked synchronous grid-connected converter

Also Published As

Publication number Publication date
CN112217237B (en) 2024-01-26

Similar Documents

Publication Publication Date Title
CN112217237A (en) Active damping control method for direct-drive wind power grid-connected system under asymmetric fault
CN112217236B (en) Virtual impedance control method for doubly-fed wind power grid-connected system under asymmetric fault
WO2021233190A1 (en) Dual-mode combined control method for multi-inverter system based on double split transformer
CN110190633B (en) Virtual synchronous machine control method under unbalanced network voltage condition
CN111130142B (en) Virtual capacitance control method for double-fed wind power generation grid-connected system
CN107732961B (en) Method for realizing subsynchronous oscillation suppression based on grid-connected converter control
CN111030139B (en) Series compensation power grid resonance suppression method based on virtual synchronous generator
CN111446716B (en) Harmonic voltage and harmonic current suppression method for VSG grid-connected system
CN113346559B (en) Low-voltage ride-through power switching control method for direct-drive wind power system under extremely weak grid
CN106972511B (en) Direct-drive wind power subsynchronous oscillation suppression method based on network side control loop optimization
CN112467785A (en) Method for improving photovoltaic fault voltage supporting capacity by using virtual impedance
WO2022022202A1 (en) Inductance current differential feedback-based virtual synchronous machine strong power grid stability control method
CN115995828A (en) Subsynchronous oscillation suppression method and system for virtual synchronous doubly-fed fan through series compensation grid-connected system
CN112467787B (en) Method for inhibiting sudden rise of voltage during photovoltaic grid-connected fault removal
CN110417059B (en) Transient stability control method for renewable energy power generation base
CN113241748A (en) Transient overvoltage suppression method and system for power electronic converter connected to weak power grid
CN115995813B (en) Grid-connected inverter oscillation suppression strategy based on hybrid damping
CN111313455B (en) Control method for suppressing commutation failure of energy storage STATCOM and inverter control method
CN114244173A (en) Grid voltage feedforward method for weak grid AC device, electronic equipment and medium
CN109861308B (en) Virtual synchronous generator fault ride-through control method
Li et al. Parallel impedance-reshaping control strategy for suppressing wide range high-frequency resonance of shunt compensated DFIG system
Hu et al. Stability analysis of DFIG system connected with high-frequency capacitive grid based on closed-loop current control and direct power control
Jin et al. Study on non-fundamental frequency components in the output current of DFIG-based wind turbines during faults
Hu et al. Impedance modeling and stability analysis of DFIG system based on direct power control without PLL
CN116667350B (en) Grid-connected harmonic current suppression method and device for grid-connected inverter based on phase compensation

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant