CN109638880A - Current transformer grid-connected system stability improvement method based on admittance shaping range - Google Patents

Current transformer grid-connected system stability improvement method based on admittance shaping range Download PDF

Info

Publication number
CN109638880A
CN109638880A CN201811569979.9A CN201811569979A CN109638880A CN 109638880 A CN109638880 A CN 109638880A CN 201811569979 A CN201811569979 A CN 201811569979A CN 109638880 A CN109638880 A CN 109638880A
Authority
CN
China
Prior art keywords
admittance
grid
generalized
vsc
stability
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
CN201811569979.9A
Other languages
Chinese (zh)
Other versions
CN109638880B (en
Inventor
辛焕海
董炜
杨超然
宫泽旭
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.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
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 Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201811569979.9A priority Critical patent/CN109638880B/en
Publication of CN109638880A publication Critical patent/CN109638880A/en
Application granted granted Critical
Publication of CN109638880B publication Critical patent/CN109638880B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • 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
    • H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Inverter Devices (AREA)

Abstract

本发明公开了一种基于导纳整形范围的变流器并网系统稳定性提高方法。建立变流器并网系统的等效原‑对偶复电路，得到广义导纳的模态功率；计算模态功率的实部虚部和变流器并网系统的特征值对广义导纳的变化倍数的灵敏度，利用灵敏度能反应该广义导纳对变流器并网系统振荡的影响程度；计算变流器广义导纳所需的改变量的相角范围和幅值范围，在系统稳定裕度确定情况下，根据改变量的相角范围和幅值范围确定改变量，用改变量调整广义导纳，从而提高系统的稳定性，达到振荡抑制的效果。本发明提出的变流器并网系统阻抗整形分析方法能够有效提高系统稳定性或稳定裕度，抑制系统振荡，保证系统的安全稳定运行。The invention discloses a method for improving the stability of a grid-connected system of a converter based on an admittance shaping range. Establish the equivalent original-dual complex circuit of the grid-connected converter system to obtain the modal power of the generalized admittance; calculate the real and imaginary parts of the modal power and the change of the eigenvalues of the grid-connected converter system to the generalized admittance The sensitivity of multiples can be used to reflect the degree of influence of the generalized admittance on the oscillation of the converter grid-connected system; In the case of determination, the change amount is determined according to the phase angle range and amplitude range of the change amount, and the generalized admittance is adjusted by the change amount, thereby improving the stability of the system and achieving the effect of oscillation suppression. The impedance shaping analysis method of the grid-connected system of the converter proposed by the invention can effectively improve the stability or stability margin of the system, suppress the oscillation of the system, and ensure the safe and stable operation of the system.

Description

Current transformer grid-connected system stability improvement method based on admittance shaping range
Technical field
The present invention relates to a kind of current transformer grid-connected system stability improvement methods, especially by the equivalent original-of computing system Mode oscillation under dual circuit, determines the calculating side of the stable generalized admittance of raising system or current transformer admittance knots modification range Method, and then adjust system parameter optimization or compensation tache is added to inhibit the method for system oscillation, realize that stability improves.
Background technique
As the renewable and clean energy resources such as wind, light access AC network, the power electronics degree of AC network on a large scale It is continuously improved, due to the coupling between current transformer and power grid, system is easy to produce complicated oscillation problem, renewable energy The grid-connected safety and stability to system propose new challenge.Instability problem caused by current transformer is grid-connected seriously constrains can be again The development and large scale investment of the raw energy, it is therefore proposed that reliable efficient oscillation, which inhibits strategy also, becomes urgently to be resolved important Problem.
The impedance model of current transformer grid-connected system is established using generalized impedance theory, and equivalent former-right by computing system The mode power of even compound circuit, can analyze the small signal stability of system.But this method does not shake to mode power and system The relationship of swinging is described in detail, and provides the admittance change direction for inhibiting system oscillation and shaping range, therefore cannot specifically give The system oscillation based on compound circuit mode power analysis inhibits strategy out.
Summary of the invention
To solve the above problems, the invention proposes a kind of current transformer grid-connected system stability based on admittance shaping range Improvement method, Physical Mechanism are clear, it is intended to identify in current transformer grid-connected system and act on apparent position, optimization to system oscillation Relevant parameter introduces compensation tache change current transformer admittance, to make the equivalent original of system-all generalized admittances of antithesis compound circuit Mode power it is the sum of useful be positive, system small interference stability.
Technical solution of the present invention uses following steps:
1) the equivalent original-antithesis compound circuit for establishing current transformer grid-connected system, obtains generalized admittance YeiMode power Oei；
2) the real part imaginary part of mode power and the characteristic value s of current transformer grid-connected system are calculated to generalized admittance YeiVariation times Number keiSensitivity, the influence degree that the generalized admittance vibrates current transformer grid-connected system can be reacted using sensitivity；
The characteristic value s of current transformer grid-connected system is the characteristic root of the state equation of current transformer grid-connected system.
3) knots modification △ Y needed for calculating current transformer generalized admittancee1_VSC、△Ye2_VSCWith △ Ye3_VSCPhase angle range and Amplitude range determines knots modification according to the phase angle range of knots modification and amplitude range under system stability margin certain situation, uses Knots modification adjusts generalized admittance, to improve the stability of system, achievees the effect that oscillation inhibits.
In the present invention, the imaginary part of the mode power, i.e. mode power are idle Im (Oei) it is timing, it is considered as oscillation energy storage member Part is not controlled；Active Re (the O of the real part of the mode power, i.e. mode powerei) when being negative, it is considered as oscillation energy source member Part need to be controlled.
The step 1) specifically:
Using the equivalent original-antithesis compound circuit for establishing current transformer grid-connected system based on generalized impedance modeling method, according to change The voltage equation at equivalent original-antithesis compound circuit interior joint of device grid-connected system is flowed, each generalized admittance Y is obtainedeiThe electricity at both ends Pressure difference UeiWith flow through generalized admittance YeiElectric current Iei, then by voltage difference UeiConjugation and electric current IeiConjugation and mode power because Sub- oeiMultiplication obtains generalized admittance YeiMode power Oei；It is specifically calculated using the following equation and obtains each generalized admittance Yei? Mode power O under External forcing frequency of oscillationei(s1):
Y (s)=Ye_VSC(s)+Ye_L(s)+Ye_C(s)
Wherein, UeiFor circuit voltage vector U component in i-th of generalized admittance YeiThe voltage at both ends, circuit voltage vector U=[UP,UD]T, T representing matrix transposition, UPAnd UDIndicate equivalent original-antithesis compound circuit primary voltage and dual voltage；YeiIt indicates I-th of generalized admittance, IeiTo pass through i-th of generalized admittance YeiElectric current；Arg () expression takes phase angle, and subscript " * " expression takes Conjugation；Subscript " ' " indicate partial derivative,Expression asks Y (s) in s=s1The partial derivative at place, Y (s) indicate to become The sum of the admittance matrix of device grid-connected system is flowed, s indicates system features value, s1Indicate that Oscillatory mode shape, j indicate imaginary number, oeFor mode function The rate factor；Ye_VSC(s)、Ye_L(s) and Ye_CIt (s) is respectively current transformer, power grid inductance and the filtering in equivalent original-antithesis compound circuit The admittance matrix of capacitor can be directly obtained from the equivalent original-dual circuit of system.
Equivalent original-antithesis compound circuit is mainly by three generalized admittance Y of current transformerei, power grid inductance two generalized admittances YeiWith two generalized admittance Y of filter capacitoreiIt constitutes, as shown in Figure 3.It is divided into primary circuit and dual circuit two parts, primary circuit Including the second generalized admittance of power grid inductance Ye2_L, the second generalized admittance of filter capacitor Ye2_C, the sub generalized admittance of current transformer and unsteady flow The second generalized admittance of device Ye2_VSCFour generalized admittances, dual circuit include power grid inductance third generalized admittance Ye3_L, filter capacitor Third generalized admittance Ye3_C, current transformer two generalized admittances, current transformer third generalized admittance Ye3_VSCFour generalized admittances；Power grid The second generalized admittance of inductance Ye2_L, the second generalized admittance of filter capacitor Ye2_CWith the second generalized admittance of current transformer Ye2_VSCIt is connected in parallel on change Between the one end and ground connection for flowing two generalized admittance of device, power grid inductance third generalized admittance Ye3_L, filter capacitor third broad sense leads Receive Ye3_CWith current transformer third generalized admittance Ye3_VSCIt is connected in parallel between one end and ground connection of the sub generalized admittance of current transformer, first It connects, and then goes here and there between the other end of a the first generalized admittance of current transformer and the other end of second the first generalized admittance of current transformer Connection constitutes the first generalized admittance of current transformer Ye1_VSC。
The current transformer grid-connected system ideally worked normally is not affected by interference (vibrating without External forcing)；Actually answer It only (is vibrated without External forcing) by small interference with the current transformer grid-connected system of middle normal work, therefore equivalent original-antithesis Compound circuit can be made to simplify processing, can ignore the second generalized admittance of power grid inductance Ye2_LExternal disturbance source original point between ground Measure Δ EPWith power grid inductance third generalized admittance Ye3_LExternal disturbance source between ground is to even component Δ ED。
Apparent generalized admittance Y is acted on to system oscillation according to the identification of the real and imaginary parts of mode powerei。
In the step 1):
1.1) the crucial oscillation energy-storage travelling wave tube of system is determined.Calculate generalized admittance YeiMode power imaginary part, i.e. mode Power is idle Im (Oei), if being positive, mean YeiIt plays and increases s1Imaginary part effect, be system oscillation energy-storage travelling wave tube, and | Im(Oei) | maximum system oscillation energy-storage travelling wave tube, to influence maximum crucial oscillation energy-storage travelling wave tube to system oscillation frequency of oscillation, Its generalized admittance YeiIt needs to adjust.
1.2) the crucial oscillation energy source element of system is determined.Calculate generalized admittance YeiMode power real part, i.e. mould Active Re (the O of state powerei), if the index is negative, mean YeiPlay the role of enhancing system oscillation, is the oscillation of system Energy source element, and | Re (Oei) | maximum oscillation energy source element, to influence maximum crucial oscillation vibration to system stability Swing source element, generalized admittance YeiIt needs to adjust.
1.3) according to generalized admittance YeiMost effective setting program is chosen in sensitivity to system stability.When broad sense is led It receives by YeiBecome (1+kei)YeiIn the process, then computing system characteristic value s is to generalized admittance YeiVariation coefficient keiSensitivity.
The step 2) specifically:
The real part imaginary part of mode power and the characteristic value s of system are to generalized admittance YeiVariation coefficient keiSensitivityExpression formula are as follows:
ko=| UTY′(s1)U|-1
Wherein, U=[UP,UD]T, s1Indicate Oscillatory mode shape,Expression asks Y (s) in s=s1That locates is inclined Derivative, Y (s) indicate the sum of the admittance matrix of current transformer grid-connected system, s1Indicate that Oscillatory mode shape, j indicate imaginary number, oeFor mode function The rate factor；Ye_VSC(s)、Ye_L(s) and Ye_CIt (s) is respectively current transformer, power grid inductance and the filtering in equivalent original-antithesis compound circuit The admittance matrix of capacitor.
Sensitivity reflects the relationship of characteristic value s variation with generalized admittance variation, and numerical value is bigger to represent generalized impedance YeiEvery increasing Add a fixed proportion kei, system features value variable quantity is bigger, i.e., brighter to system stability influence degree to the generalized admittance It is aobvious, it is preferentially considered as being adjusted.
By the generalized admittance Y for calculating crucial oscillation energy-storage travelling wave tube and crucial oscillation energy source elementeiTo system stability Sensitivity, according to the descending sequence of sensitivity to needing setting means to be ranked up.The maximum element of sensitivity is at this Weakest link under operating condition should consider to carry out it parameter optimization first or compensate, be insufficient for if adjusting it Stability margin requirement is considering the generalized admittance Y to next elementeiIt is adjusted, until system is met the requirements.
More each generalized admittance YeiSensitivity, sensitivity it is bigger to current transformer grid-connected system oscillation influence it is bigger, Peak response is taken to carry out admittance adjusting.
In the present invention, sensitivity and knots modification are directed to three current transformer generalized admittances.
The knots modification △ Y of three current transformer generalized admittances in the equivalent original-antithesis compound circuite1_VSC、△Ye2_VSCAnd △ Ye3_VSCPhase angle range specifically calculate separately are as follows:
Wherein, oeFor mode power factor, α indicates Oscillatory mode shape s1Phase angle；
The knots modification △ Y of three generalized admittances of three inversion elements in the equivalent original-antithesis compound circuite1_VSC、△ Ye2_VSCWith △ Ye3_VSCAmplitude range specifically calculate separately are as follows:
Wherein, s ' is the system features value considered after stability margin, oscillation mode when being critical state；OsumIt indicates to become Flow the sum of the mode power of all generalized admittances in device grid-connected system.
In the step 3), knots modification is set according to the phase angle range of knots modification and amplitude range, with knots modification to broad sense Admittance parameter optimizes adjustment or compensation tache is added in current transformer (inversion element) controller and is adjusted, and makes equivalent Original-all generalized admittances of antithesis compound circuit mode power is the sum of useful to be positive and meets certain nargin, reaches what oscillation inhibited Effect.
In the present invention, by the generalized admittance Y for changing inversion elemente1_VSC、Ye2_VSC、Ye3_VSCRealize that system oscillation inhibits Purpose, the parameter optimization of current transformer grid-connected system or the design of compensation tache can be instructed according to the knots modification, to improve The stability of system achievees the effect that oscillation inhibits.
The beneficial effects of the present invention are:
The method of the present invention passes through the equivalent original-of computing system based on the equivalent original of system-antithesis compound circuit mode power analysis The mode hunting power of antithesis compound circuit identifies the position in current transformer grid-connected system to stability high sensitivity, optimizes and revises Parameter introduces compensation tache change current transformer admittance, can effectively improve system stability or stability margin, inhibit system vibration It swings, guarantees the safe and stable operation of system.
Detailed description of the invention
Fig. 1 is the equivalent circuit diagram that current transformer is grid-connected in simulating, verifying of the embodiment of the present invention.
Fig. 2 is current transformer vector controlled block diagram in simulating, verifying of the embodiment of the present invention.
Fig. 3 is equivalent original-antithesis compound circuit of system in simulating, verifying of the embodiment of the present invention.
Fig. 4 is the oscillating curve in simulating, verifying of the embodiment of the present invention in primal system electromagnetic transient simulation.
Fig. 5 is system features value moving range schematic diagram in simulating, verifying of the embodiment of the present invention.
Fig. 6 is system balance Absent measures block diagram in simulating, verifying of the embodiment of the present invention.
Fig. 7 is the oscillating curve after compensating in simulating, verifying of the embodiment of the present invention in system electromagnetic transient simulation.
Specific embodiment
The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
The specific embodiment implemented according to the method for the present invention content intact is as follows:
Current transformer and pessimistic concurrency control are built in Matlab/Simulink software, as shown in Figure 1.Wherein current transformer uses base In the bicyclic vector control strategy of phaselocked loop, as shown in Fig. 2, and current transformer output power power factor be 1.In Fig. 1 and Fig. 2 Each variable physical meaning is as shown in table 1 below:
1 current transformer grid-connected system variable of table corresponds to table
The parameter value of variable is as shown in table 2 below in current transformer grid-connected system:
The parameter value of current transformer variable in 2 embodiment simulating, verifying of table
System original-antithesis the compound circuit formed by generalized impedance theoretical modeling is as shown in Figure 3.It is calculated according to 2 data of table Each generalized admittance and current transformer admittance and its mode power are as shown in table 3 in acquisition system.Line inductance is further increased, it will be real The inductance Lg for applying alternating current net side in example 1 increases to 0.56p.u. by 0.55p.u., by the inductance of alternating current net side in embodiment 2 Lg increases to 0.41p.u. by 0.4p.u., and each generalized admittance and current transformer admittance and its mode power are as shown in table 4 in system, Since system mode power is by just becoming negative, system is changed into time-dependent system by stabilization, and the system is in electromagnetic transient simulation There is wild effect as shown in figure 4, as seen from the figure, system oscillation is changed into diverging by decaying in waveform.
Each generalized admittance and its mode watt level under 3 frequency of oscillation of table
Table 4 changes the generalized admittance and mode power after line inductance
The setting principle changes current transformer admittance Y according to the present inventiong11And Yg22, wherein Yg11And Yg22For current transformer admittance The diagonal element of matrix, there are relationships with current transformer generalized admittance:
Therefore, setting principle is consistent with current transformer generalized admittance setting principle, and the two is of equal value and can mutual inversion of phases.
The system features value moving range according to obtained by step 2.1) is as shown in Figure 5.
Respectively to Yg11And Yg22It is adjusted, takes the critical state for meeting a nargin, at this time Oscillatory mode shape knots modification Δ s1Phase angle beta=- π, compensation tache shown in Fig. 6, compensation tache input signal, output is added in current transformer shown in Fig. 1 control Signal application position and parameter are as shown in table 5.
5 compensation tache parameter of table
It is added before and after compensation tache, system converter admittance and its mode power are as shown in table 6.
The compensation of table 6 front and back system converter admittance and its mode power
As can be seen from Table 6:
1) for embodiment 1, Y is adjustedg11Afterwards, Og11After becoming -0.86-1.25i from -0.92-1.25i, system features value By horizontal left, system stability enhancing；Adjust Yg22Afterwards, Og22After becoming 0.89-1.31i from -0.95-1.31i, system features Value is -1.5891+89.1203i, system stability enhancing by -0.3230+89.1128i horizontal left.
2) for embodiment 2, adjust Yg11Afterwards, Og11After becoming -0.05+0.55i from -0.12+0.55i, system features value It is -1.43+68.79i, system stability enhancing by -0.07+68.94i horizontal left；Adjust Yg22Afterwards, Og22By -0.41+ After 0.82i becomes -0.35+0.82i, system features value is -1.36+68.80i by -0.07+68.94i horizontal left, and system is steady Qualitative enhancing.
It in summary it can be seen, for 2 two systems of embodiment 1 and embodiment, the setting method based on mode power changes Yg11Or Yg22Afterwards, system oscillation mode horizontal left can be made, enhance the stability of system.In addition, electromagnetic transient simulation As a result it can also illustrate above-mentioned conclusion:
1) for embodiment 1, in t=0.5s, the line inductance in AC network becomes 0.55p.u. from 0.54p.u., In t=4.5s, line inductance becomes 0.56p.u., adjusts Yg11And Yg22Afterwards, the end voltage oscillation curve of system is respectively such as Fig. 7 (a) and shown in Fig. 7 (b).Comparison diagram 5 (a) is as can be seen that adjusting Yg11Or Yg22Afterwards, when line inductance is 0.55p.u., in system Oscillation gradually decay, the rate of decay is significantly faster than that primal system, and when line inductance is increased to 0.56p.u., in system Oscillation still gradually decays, system small interference stability.This illustrates to adjust Yg11Or Yg22The stabilization of 1 system of embodiment is improved afterwards Property.
2) for embodiment 2, in t=0.5s, the line inductance in AC network becomes 0.4p.u. from 0.39p.u., In t=4.5s, line inductance becomes 0.41p.u., adjusts Yg11And Yg22Afterwards, end voltage oscillation curve such as Fig. 7 (c) of system With shown in Fig. 7 (d).Comparison diagram 5 (b) is as can be seen that adjusting Yg11Or Yg22Afterwards, when line inductance is 0.40p.u., in system Oscillation gradually decays, and the rate of decay is significantly faster than that primal system, and the vibration when line inductance is increased to 0.41p.u., in system It swings and still gradually decays, system small interference stability.This illustrates to adjust Yg11Or Yg22Improve the stability of 1 system of embodiment.
Therefore, the admittance shaping range computation method proposed by the invention based on mode power can pass through analysis system Equivalent original-antithesis compound circuit mode power, identifying system propose to improve system to the serious weak link of stability destroying infection The calculation method of the current transformer device admittance shaping range for stability of uniting, and then instruct the parameter optimization of system or setting for compensation tache Meter, to achieve the effect that inhibit system oscillation, can be seen that this method significant effect from specific implementation case and can quantitatively carve Draw the inhibitory effect of oscillation.
Above-mentioned specific embodiment is used to illustrate the present invention, rather than limits the invention, of the invention In spirit and scope of protection of the claims, to any modifications and changes that the present invention makes, protection model of the invention is both fallen within It encloses.

Claims (4)

1.一种基于导纳整形范围的变流器并网系统稳定性提高方法，其特征在于包括以下步骤：1. a method for improving the stability of a converter grid-connected system based on an admittance shaping range, is characterized in that comprising the following steps: 1)建立变流器并网系统的等效原-对偶复电路，得到广义导纳Yei的模态功率Oei；1) Establish the equivalent original-dual complex circuit of the grid-connected converter system, and obtain the modal power O ei of the generalized admittance Ye ei ; 2)计算模态功率的实部虚部和变流器并网系统的特征值s对广义导纳Yei的变化倍数kei的灵敏度，利用灵敏度能反应该广义导纳对变流器并网系统振荡的影响程度；2) Calculate the real and imaginary parts of the modal power and the sensitivity of the eigenvalue s of the grid-connected converter system to the change factor ke ei of the generalized admittance Ye ei , and use the sensitivity to reflect the generalized admittance to the grid-connected converter. The degree of influence of system oscillation; 3)计算变流器广义导纳所需的改变量△Ye1_VSC、△Ye2_VSC和△Ye3_VSC的相角范围和幅值范围，在系统稳定裕度确定情况下，根据改变量的相角范围和幅值范围确定改变量，用改变量调整广义导纳，从而提高系统的稳定性，达到振荡抑制的效果。3) Calculate the phase angle range and amplitude range of the changes △Y e1_VSC , △Y e2_VSC and △Y e3_VSC required for the generalized admittance of the converter. When the system stability margin is determined, according to the phase angle range of the change and the amplitude range to determine the change amount, and use the change amount to adjust the generalized admittance, so as to improve the stability of the system and achieve the effect of oscillation suppression. 2.根据权利要求1所述的一种基于导纳整形范围的变流器并网系统稳定性提高方法，其特征在于：所述步骤1)具体为：2. The method for improving the stability of a grid-connected converter system based on an admittance shaping range according to claim 1, wherein the step 1) is specifically: 采用基于广义阻抗建模方法建立变流器并网系统的等效原-对偶复电路，根据变流器并网系统的等效原-对偶复电路中节点处的电压方程，得到各个广义导纳Yei两端的电压差Uei和流过广义导纳Yei的电流Iei，再将电压差Uei的共轭和电流Iei的共轭和模态功率因子oei相乘得到广义导纳Yei的模态功率Oei；具体是采用以下公式计算获得各广义导纳Yei在外界强迫振荡频率下的模态功率Oei(s1)：The equivalent original-dual complex circuit of the grid-connected converter system is established by using the generalized impedance modeling method. According to the voltage equation at the node in the equivalent original-dual complex circuit of the grid-connected converter system, each generalized admittance is obtained. The voltage difference U ei across Ye ei and the current I ei flowing through the generalized admittance Ye ei are multiplied by the conjugate of the voltage difference U ei and the conjugate of the current I ei and the modal power factor o ei to obtain the generalized admittance The modal power O ei of Ye ei ; specifically, the modal power O ei (s 1 ) of each generalized admittance Ye ei at the external forced oscillation frequency is obtained by calculating the following formula: Y(s)＝Ye_VSC(s)+Ye_L(s)+Ye_C(s)Y(s)=Y e_VSC (s)+Y e_L (s)+Y e_C (s) 其中，Uei为电路电压向量U的分量在第i个广义导纳Yei两端的电压，电路电压向量U＝[UP,UD]T，T表示矩阵转置，UP和UD表示等效原-对偶复电路的原电压和对偶电压；Yei表示第i个广义导纳，Iei为通过第i个广义导纳Yei的电流；arg(·)表示取相角，上标“*”表示取共轭；上标“'”表示偏导数，表示求Y(s)在s＝s1处的偏导数，Y(s)表示变流器并网系统的导纳矩阵之和，s表示系统特征值，s1表示振荡模态，j表示虚数，oe为模态功率因子；Ye_VSC(s)、Ye_L(s)和Ye_C(s)分别为等效原-对偶复电路中的变流器、电网电感和滤波电容的导纳矩阵。Among them, U ei is the voltage of the component of the circuit voltage vector U at both ends of the i-th generalized admittance Y ei , the circuit voltage vector U=[U P , U D ] T , T represents the matrix transpose, and U P and U D represent The original voltage and dual voltage of the equivalent original-dual complex circuit; Ye ei represents the ith generalized admittance, I ei is the current passing through the ith generalized admittance Ye ei ; arg( ) represents the phase angle, superscript "*" means taking conjugate; superscript "'" means partial derivative, represents the partial derivative of Y(s) at s=s 1 , Y(s) represents the sum of the admittance matrices of the grid-connected converter system, s represents the eigenvalue of the system, s 1 represents the oscillation mode, and j represents the imaginary number , o e is the modal power factor; Y e_VSC (s), Y e_L (s) and Y e_C (s) are the admittance matrices of the converter, grid inductance and filter capacitor in the equivalent original-dual complex circuit, respectively . 3.根据权利要求1所述的一种基于导纳整形范围的变流器并网系统稳定性提高方法，其特征在于：所述步骤2)具体为：3. The method for improving the stability of a grid-connected converter system based on an admittance shaping range according to claim 1, wherein the step 2) is specifically: 模态功率的实部虚部和系统的特征值s对广义导纳Yei的变化系数kei的灵敏度的表达式为：Sensitivity of the real and imaginary parts of the modal power and the eigenvalue s of the system to the coefficient of variation ke ei of the generalized admittance Ye ei The expression is: ko＝|UTY′(s1)U|-1 k o =|U T Y′(s 1 )U| -1 其中，U＝[UP,UD]T，s1表示振荡模态，表示求Y(s)在s＝s1处的偏导数，Y(s)表示变流器并网系统的导纳矩阵之和，s1表示振荡模态，j表示虚数，oe为模态功率因子；Ye_VSC(s)、Ye_L(s)和Ye_C(s)分别为等效原-对偶复电路中的变流器、电网电感和滤波电容的导纳矩阵。Among them, U=[U P , U D ] T , s 1 represents the oscillation mode, represents the partial derivative of Y(s) at s=s 1 , Y(s) represents the sum of the admittance matrix of the grid-connected system of the converter, s 1 represents the oscillation mode, j represents the imaginary number, and o e represents the mode Power factor; Y e_VSC (s), Y e_L (s) and Y e_C (s) are the admittance matrices of the converter, grid inductance and filter capacitor in the equivalent original-dual complex circuit, respectively. 4.根据权利要求1所述的一种基于导纳整形范围的变流器并网系统稳定性提高方法，其特征在于：所述等效原-对偶复电路中三个变流器广义导纳的改变量△Ye1_VSC、△Ye2_VSC和△Ye3_VSC的相角范围具体分别计算为：4. The method for improving the stability of a grid-connected converter system based on an admittance shaping range according to claim 1, wherein: the generalized admittance of three converters in the equivalent original-dual complex circuit The phase angle ranges of the changes △Y e1_VSC , △Y e2_VSC and △Y e3_VSC are calculated as: 其中，oe为模态功率因子，α表示振荡模态s1的相角；Among them, o e is the modal power factor, and α represents the phase angle of the oscillation mode s 1 ; 所述等效原-对偶复电路中三个逆变元件的三个广义导纳的改变量△Ye1_VSC、△Ye2_VSC和△Ye3_VSC的幅度范围具体分别计算为：The amplitude ranges of the three generalized admittance changes ΔY e1_VSC , ΔY e2_VSC and ΔY e3_VSC of the three inverter elements in the equivalent original-dual complex circuit are specifically calculated as: 其中，s′为考虑稳定裕度后的系统特征值，为临界状态时的振荡模式；Osum表示变流器并网系统中所有广义导纳的模态功率之和。Among them, s' is the eigenvalue of the system after considering the stability margin, which is the oscillation mode in the critical state; O sum is the sum of the modal powers of all generalized admittances in the grid-connected system of the converter.
CN201811569979.9A 2018-12-21 2018-12-21 Converter grid-connected system stability improving method based on admittance shaping range Active CN109638880B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811569979.9A CN109638880B (en) 2018-12-21 2018-12-21 Converter grid-connected system stability improving method based on admittance shaping range

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811569979.9A CN109638880B (en) 2018-12-21 2018-12-21 Converter grid-connected system stability improving method based on admittance shaping range

Publications (2)

Publication Number Publication Date
CN109638880A true CN109638880A (en) 2019-04-16
CN109638880B CN109638880B (en) 2022-04-05

Family

ID=66076257

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811569979.9A Active CN109638880B (en) 2018-12-21 2018-12-21 Converter grid-connected system stability improving method based on admittance shaping range

Country Status (1)

Country Link
CN (1) CN109638880B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114552648A (en) * 2022-03-09 2022-05-27 浙江大学 A method and device for improving the stability of a grid-connected system of a new energy base

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106532685A (en) * 2016-10-26 2017-03-22 浙江大学 Generalized impedance criterion calculation method for stability analysis of grid-connected inverter and application
CN106786776A (en) * 2017-02-15 2017-05-31 云南电网有限责任公司 A kind of method using generalized impedance method analysis grid-connected inverter system stability is corrected
US20180131183A1 (en) * 2015-07-29 2018-05-10 Incheon University Industry Academic Cooperation Foundation System and method for controlling multi-frequencies of a microgrid
CN108509697A (en) * 2018-03-19 2018-09-07 浙江大学 A kind of converter system original-dual circuit modeling method considering disturbance

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180131183A1 (en) * 2015-07-29 2018-05-10 Incheon University Industry Academic Cooperation Foundation System and method for controlling multi-frequencies of a microgrid
CN106532685A (en) * 2016-10-26 2017-03-22 浙江大学 Generalized impedance criterion calculation method for stability analysis of grid-connected inverter and application
CN106786776A (en) * 2017-02-15 2017-05-31 云南电网有限责任公司 A kind of method using generalized impedance method analysis grid-connected inverter system stability is corrected
CN108509697A (en) * 2018-03-19 2018-09-07 浙江大学 A kind of converter system original-dual circuit modeling method considering disturbance

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
蒙志全等: "控制系统扰动下并网变流器广义阻抗测量方法", 《中国电机工程学报》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114552648A (en) * 2022-03-09 2022-05-27 浙江大学 A method and device for improving the stability of a grid-connected system of a new energy base

Also Published As

Publication number Publication date
CN109638880B (en) 2022-04-05

Similar Documents

Publication Publication Date Title
CN110365231B (en) Single-phase device multiplexing type active power decoupling cascade rectifier and control method thereof
CN109962495B (en) Method for positioning and restraining ultralow-frequency oscillation disturbance source
CN110492479B (en) A Moment of Inertia and Damping Identification Method for Distributed Grid-connected Equipment
CN112436537B (en) Broadband oscillation suppression method for offshore wind power plant through flexible direct current delivery system
CN113328447B (en) Method and system for determining key influence links and parameters of oscillation of direct-drive fan system
CN108199396A (en) The virtual excitation closed-loop control system of energy storage inverter and its design method
CN108880300B (en) Double-fed fan rectifier impedance calculation method based on double closed-loop control
CN105827133A (en) Distributed inverter resonance suppression method and system based on capacitor voltage prediction
CN111009921A (en) Oscillation analysis method of grid-connected DFIG based on Nyquist stability criterion
CN108767869A (en) A kind of static var compensator voltage adjusting method based on artificial neural network
CN111884259A (en) An adaptive equivalence method for site-level wind turbines considering the stability characteristics of small disturbances in the system
CN104362653A (en) Power system stabilizer
CN109638880A (en) Current transformer grid-connected system stability improvement method based on admittance shaping range
CN103501016B (en) TCSC (thyristor controlled series capacitor) control method and system based on process neural network
CN113241753B (en) An Improved Virtual Generator Control Method for DC Microgrid
Yan et al. Interaction analysis of multi VSCs integrated into weak grid in current control time-scale
CN110427734B (en) System side harmonic impedance estimation method and system based on variance minimum criterion
CN113346561B (en) Stability analysis method for energy storage droop compensation module
CN113708373B (en) A method and system for judging broadband oscillation stability of closed-loop power system
CN111525617A (en) VSG power decoupling control method and system based on excitation regulation
CN111030136A (en) Design method for power system stabilizer of speed regulator of hydroelectric generating set
CN115207988A (en) Control method and system for new energy power generation converter
CN110518625A (en) A kind of gird-connected inverter DC component suppressing method of variable learning rate BP-PID control
CN113346517B (en) A Damping Support Strategy for Virtual Synchronous Machines
CN116384032A (en) A damping path analysis method suitable for wind power transmission system through LCC-HVDC

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