CN109494722A - Grid side equivalent impedance modeling method and system - Google Patents

Grid side equivalent impedance modeling method and system Download PDF

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Publication number
CN109494722A
CN109494722A CN201811385751.4A CN201811385751A CN109494722A CN 109494722 A CN109494722 A CN 109494722A CN 201811385751 A CN201811385751 A CN 201811385751A CN 109494722 A CN109494722 A CN 109494722A
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grid
model
voltage
impedance
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CN109494722B (en
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朱淼
徐莉婷
侯川川
蔡旭
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Shanghai Jiaotong University
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Shanghai Jiaotong University
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/10Flexible AC transmission systems [FACTS]

Abstract

The present invention provides a kind of grid side equivalent impedance modeling method and systems, it include: polymerization equivalent step: using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling unit, the grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;Equivalent impedance model foundation step: using the grid-connected admittance model of voltage-source type Static Var Compensator and the coupling of line admittance model and impedance relationship, the grid side equivalent impedance model run containing multiple voltage-source type Static Var Compensator is established.Accurate, highly linearized admittance model is established, the validity of the grid-connected admittance model of multiple VSC type STATCOM is demonstrated from theoretical method;The meter obtained using the numerical relation of admittance and impedance and the grid side equivalent impedance of multiple VSC type STATCOM operation, are had modified the impedance operator of existing line model, are conducive to provide impedance reference for the stability problem of new-energy grid-connected.

Description

Grid side equivalent impedance modeling method and system
Technical field
The present invention relates to exchange transmission & distribution electrical domains, and in particular, to meter and voltage-source type (VSC) Static Var Compensator (STATCOM) grid side equivalent impedance modeling method and system.
Background technique
With the serious environmental problems that are increasingly depleted, and being caused of the traditional energies such as coal, petroleum, natural gas, promote Development and utilization renewable energy has become the important means for solving energy problem at this stage.China has built more in " three Norths " area Locate ten million multikilowatt wind-powered electricity generation/photovoltaic base, and is sent out using extra-high voltage direct-current and develop benefit as the current renewable energy in China Leading form.Renewable energy power generation base direct current delivery system includes wind light generation, reactive compensation, direct current transportation, same The diversification equipment such as generator is walked, power electronics equips capacity and is much larger than synchronous generator capacity, and system effective inertia mass is low, short-circuit Than small, this makes system that the several hundred Hz oscillation problems of several Hz- repeatedly occur.The Xinjiang renewable energy source base direct current to have put into operation at present Has there are many problems due to system oscillation in sending end wind power base, even results in fired power generating unit chaser.
The scale and capacity of distributed generation system are constantly expanding, control strategy more sophisticated, between diversification equipment Voltage angle coupling, renewable energy power generation equipment dynamic characteristic and the conventional synchronization generator that Multiple Time Scales are presented are totally different, These features cause the transient behavior Evolution of renewable energy power generation base direct current delivery system to complicate.At this point, grid-connected Reciprocation between inverter and gird-connected inverter, between gird-connected inverter and power grid can become readily apparent from, and be also easier to Cause complicated oscillation problem, threat is generated to the stable operation of network system.
It is led to the problem of new-energy grid-connected, current strategy is to change vibration by the output impedance characteristic of control equipment Machine-net total impedance at frequency is swung, is optimized including new energy base polymorphic type equipment impedance operator more with Active control device Equipment is coordinated oscillation and is inhibited.Impedance analysis method, will when studying the impedance stability of gird-connected inverter and power grid interactive system The two is considered as two independent subsystems, establishes impedance model respectively according to respective control structure and parameter attribute, utilizes line Property network structure indicates the equivalent circuit of the interactive system, then using impedance stability criterion come analysis system stability.It is existing Grid-connected system impedance analysis research grid side impedance is directly equivalent to line reactance Zg, grid-connected system impedance analysis principle As shown in Figure 1.This grid side equivalent impedance ignores reactive power compensator (such as VSC type STATCOM) during line transmission Bring impedance variations, equivalent model have deviateed actual condition.In equipment control mode multiplicity, the network architecture is complicated, equips Between there are in the case where dynamic interaction, there is an urgent need to improve for traditional power grid side equivalent impedance model.
To sum up, since new energy has extensive distributivity, there is longer transmission lines between source-net-lotus With necessary potential device, reactive power compensator (such as VSC type STATCOM), from the point of view of new-energy grid-connected side, net side impedance becomes An important factor for can not ignore.
Summary of the invention
For the defects in the prior art, the object of the present invention is to provide a kind of grid side equivalent impedance modeling method and it is System.
A kind of grid side equivalent impedance modeling method provided according to the present invention, comprising:
It polymerize equivalent step: single using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling Member, the grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model foundation step: it is led using grid-connected admittance model and the route of voltage-source type Static Var Compensator Receive model coupling and impedance relationship, establish the grid side equivalent impedance mould that runs containing multiple voltage-source type Static Var Compensator Type.
Preferably, the polymerization equivalent step includes:
Harmonic wave is carried out to the phaselocked loop of the small signal of voltage-source type Static Var Compensator, current loop control circuit in frequency domain Linearisation obtains current-responsive caused by grid disturbances under operating status using the result of harmonic linearization, and then calculates The grid-connected admittance model of voltage-source type Static Var Compensator out.
Preferably, the polymerization equivalent step further include:
The grid-connected admittance model of n voltage-source type Static Var Compensator is polymerize equivalent, n voltage-source type static reacance The polymerization equivalence principle of compensator are as follows: the capacity of polymerization model is the summation of n voltage-source type Static Var Compensator, after polymerization Output electric current expand n times;Filter inductance reduces n times;Current controller PI parameter reduces n times;Phaselocked loop input and output amount is poly- Constant before and after closing, control parameter is set still according to single voltage-source type Static Var Compensator.
Preferably, the equivalent impedance model foundation step includes:
Existing net side impedance model is reduced to equivalent circuit, network voltage source VgIt is converted into current source Ig, using more The grid-connected admittance model analytic value Y of a voltage-source type Static Var CompensatorSTATCOMIt is closed with the numerical value of existing electric network impedance model System can obtain:
Y in formulageFor the form of admittance of grid side equivalent impedance, write as impedance manner are as follows:
Z in formulageFor meter and the grid side equivalent impedance of multiple voltage-source type Static Var Compensator operation.
A kind of grid side equivalent impedance modeling provided according to the present invention, comprising:
It polymerize equivalent modules: single using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling Member, the grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model building module: it is led using grid-connected admittance model and the route of voltage-source type Static Var Compensator Receive model coupling and impedance relationship, establish the grid side equivalent impedance mould that runs containing multiple voltage-source type Static Var Compensator Type.
Preferably, the polymerization equivalent modules include:
Harmonic wave is carried out to the phaselocked loop of the small signal of voltage-source type Static Var Compensator, current loop control circuit in frequency domain Linearisation obtains current-responsive caused by grid disturbances under operating status using the result of harmonic linearization, and then calculates The grid-connected admittance model of voltage-source type Static Var Compensator out.
Preferably, the polymerization equivalent modules further include:
The grid-connected admittance model of n voltage-source type Static Var Compensator is polymerize equivalent, n voltage-source type static reacance The polymerization equivalence principle of compensator are as follows: the capacity of polymerization model is the summation of n voltage-source type Static Var Compensator, after polymerization Output electric current expand n times;Filter inductance reduces n times;Current controller PI parameter reduces n times;Phaselocked loop input and output amount is poly- Constant before and after closing, control parameter is set still according to single voltage-source type Static Var Compensator.
Preferably, the equivalent impedance model building module includes:
Existing net side impedance model is reduced to equivalent circuit, network voltage source VgIt is converted into current source Ig, using more The grid-connected admittance model analytic value Y of a voltage-source type Static Var CompensatorSTATCOMIt is closed with the numerical value of existing electric network impedance model System can obtain:
Y in formulageFor the form of admittance of grid side equivalent impedance, write as impedance manner are as follows:
Z in formulageFor meter and the grid side equivalent impedance of multiple voltage-source type Static Var Compensator operation.
Compared with prior art, the present invention have it is following the utility model has the advantages that
It 1, is minimum modeling unit, meter and phaselocked loop, current loop control ginseng with the grid-connected admittance of single VSC type STATCOM Number establishes accurate, highly linearized admittance model, the grid-connected admittance of multiple VSC type STATCOM is demonstrated from theoretical method The validity of model;
2, the grid-connected admittance model of VSC type STATCOM and the coupling of existing grid side impedance model are considered, admittance is utilized The meter obtained with the numerical relation of impedance and the grid side equivalent impedance of multiple VSC type STATCOM operation, have modified existing line The impedance operator of model is conducive to provide impedance reference for the stability problem of new-energy grid-connected.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, other feature of the invention, Objects and advantages will become more apparent upon:
Fig. 1 is grid-connected system impedance analysis schematic diagram;
Fig. 2 is meter and the grid side equivalent impedance schematic diagram of STATCOM;
Fig. 3 is phase lock control circuit diagram;
Fig. 4 is current control loop block diagram;
Fig. 5 is multiple grid-connected admittance principle figures of VSC type STATCOM;
Fig. 6 is meter and the grid side equivalent impedance schematic diagram of multiple STATCOM;
Fig. 7 is existing grid side impedance model frequency characteristic;
Fig. 8 is the grid-connected admittance model frequency characteristic of VSC type STATCOM;
Fig. 9 is meter and the grid-connected grid side impedance model frequency characteristic of multiple VSC type STATCOM.
Specific embodiment
The present invention is described in detail combined with specific embodiments below.Following embodiment will be helpful to the technology of this field Personnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill of this field For personnel, without departing from the inventive concept of the premise, several changes and improvements can also be made.These belong to the present invention Protection scope.
As shown in Fig. 2, a kind of grid side equivalent impedance modeling method provided by the invention, comprising:
It polymerize equivalent step: single using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling Member, the grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model foundation step: it is led using grid-connected admittance model and the route of voltage-source type Static Var Compensator Receive model coupling and impedance relationship, establish the grid side equivalent impedance mould that runs containing multiple voltage-source type Static Var Compensator Type.
In Fig. 2, ZgFor the equivalent grid side impedance of conventional method, numerical value is equal with transmission line reactance;YSTATCOMIt is more The grid-connected admittance of a VSC type STATCOM, numerical value is by the quantity of STATCOM and the grid-connected modulus of admittance of single VSC type STATCOM Type determines;VgFor network voltage;IgFor power network current;ZgeFor meter and the equivalent resistance of grid side of multiple VSC type STATCOM operation It is anti-.
Compared with existing electric network impedance equivalent method, it is evident that applied grid side of this patent etc. from Fig. 2 Resistance technique scheme is imitated in traditional power grid side line impedance ZgOn the basis of, it is modeling basis with power grid actual operating mode, examines The admittance Y of the grid-connected introducing of multiple VSC type STATCOM is consideredSTATCOM, so that grid side equivalent impedance model and true grid side hinder It is anti-to be more nearly, reduce the deviation of model and actual electric network operating condition.Specific implementation means are as follows:
A. the grid-connected admittance model of single VSC type STATCOM
The single grid-connected admittance model of VSC type STATCOM is the minimum modeling unit of this programme, STATCOM in modeling process In steady-working state, to each controlling unit of the small signal of STATCOM (phaselocked loop, current loop control circuit) in frequency domain Harmonic linearization is carried out, electric current caused by grid disturbances under STATCOM operating status is obtained using the result of linearisation and rings It answers, and then calculates the grid-connected admittance model of STATCOM.
Phase lock control circuit as shown in figure 3, when input fundamental voltage include positive sequence harmonic disturb when, (by taking A phase as an example) Its input voltage can be written as
Wherein vaFor A phase voltage instantaneous value, V1For fundamental voltage amplitude, ω1For fundamental voltage angular frequency, VpFor harmonic wave electricity Pressure amplitude value, ωpFor harmonic voltage angular frequency,For harmonic voltage initial phase.Control loop shows that phaselocked loop output phase angle is θPLL, coordinate transform output v when phase angle perturbation is not consideredd0、vq0Only by fundamental positive sequence voltage phase angle θ0It constitutes, meter and harmonic voltage When the corresponding perturbation phase angle Δ θ of component, θPLLIt is represented by
θPLL0+Δθ
It will perturbation phase angle Δ θ and fundamental wave phase angle theta0Separation can obtain
Wherein
The influence for ignoring higher-order shear deformation nonlinear component can obtain perturbation phase angle Δ θ approximation under frequency domain
cos(θPLL) [f]=cos (θ0)[f]-(Δθ·sinθ0)[f]
Wherein [f] be frequency domain mark (similarly hereinafter), then by phase lock control circuit it is found that meter and perturbation phase angle Δ θ when, ignore The influence of higher-order shear deformation nonlinear component, the q shaft voltage that coordinate transform exports are in frequency domain lower aprons
Wherein VqFor voltage q axis component, GpIt (s) is harmonic voltage disturbance and the transmission function between perturbation phase angle Δ θ, fpFor harmonic frequency, f1For fundamental frequency.In addition, can be seen that by phase lock control circuit
Δ θ [f]=HPLL(s) Vq[f]
Wherein, HPLLPLL transfer function is represented, is
HPLL(s)=(kpp+kpi/s)/s
K in formulappFor phaselocked loop proportionality coefficient, kpiFor phaselocked loop integral coefficient.In conjunction with the above expression formula, it is humorous positive sequence can be obtained Wave voltage disturbance and the transmission function G between perturbation phase angle Δ θp(s) it is
Wherein D (s) is carry-over factor, can be written as
When d axis is overlapped with network voltage fundamental positive sequence, converter d shaft current is watt current, and reference value is Idref;Q shaft current is reactive current, reference value Iqref, current loop control circuit is as shown in Figure 4.Consider lock perturbation phase angle Δ θ When, ignore higher-order shear deformation nonlinear component, Id、IqIt can be written as with different frequency component in a frequency domain
V in formulapFor disturbance voltage, I1For fundamental current, IpFor the harmonic current of VSC converter output, IdFor d shaft current, IqFor q shaft current,For power-factor angle.As shown in Figure 4, in steady-working state downconverter fundamental current output quantity and electricity It is equal to flow reference value, at this time H in current control loopi(s) go out values constant, d axis output steady-state value can use CdIt indicates, q axis is defeated Steady-state value can use C outqIt indicates.It is according to the output voltage that control loop can obtain converter
K in formuladqFor decoupling coefficient, EdFor the d shaft voltage of VSC converter output, EqFor the q axis electricity of VSC converter output Pressure, HiIt (s) is the PI transmission function of electric current loop.After above formula becomes three-phase coordinate form, by taking A phase as an example, converter output voltage It can be written as
EaFor the A phase voltage of VSC converter output, converter grid connection topology and current control loop H are utilizedi(s) number is exported Value can obtain
Then H when converter stable operationi(s) C is exportedd、CqFor
L is STATCOM filter inductance in formula.When network voltage injects forcing frequency, the grid-connected of VSC type STATCOM is utilized Topology, meter and positive sequence harmonic component, can obtain under the forcing frequency
Then the relationship between VSC type STATCOM positive sequence harmonic voltage, harmonic current can be abbreviated as
Ip=-YSTATCOM·Vp
Wherein YSTATCOMFor the grid-connected admittance model analytic value of VSC type STATCOM, it is
It can thus be concluded that the grid-connected admittance model of single VSC type STATCOM, the model consider steady-state operation value, current control Loop parameter, pll parameter, voltage harmonic component and current harmonics component, the grid-connected admittance model of single VSC type STATCOM Frequency-response analysis see implementation example 1.
B. the grid-connected admittance model of more a VSC type STATCOM
The capacity of single VSC type STATCOM is limited, and the grid-connected quantity by increasing VSC type STATCOM can promote idle benefit Capacity is repaid, the grid-connected admittance model of multiple VSC type STATCOM is necessarily influenced by the grid-connected quantity of VSC type STATCOM at this time.Fig. 5 is Multiple grid-connected admittance principle figures of VSC type STATCOM, it is assumed that have a VSC type STATCOM with model of n grid-connected, wherein YSTATCOM1It arrives YSTATCOMnFor the single machine admittance of each STATCOM, YSTATCOMFor the grid-connected admittance of totality of n VSC type STATCOM.This programme needle The influence that the control parameters such as phaselocked loop, electric current loop are considered to the grid-connected admittance model of multiple VSC type STATCOM, by multiple VSC Type STATCOM carries out model aggregation.N STATCOM polymerize constant value principle are as follows: polymerization model VSC converter capacity is n The summation of STATCOM, that is, STATCOM output electric current expands n times after polymerizeing;Filter inductance reduces n times;Current controller PI parameter Reduce n times;Phaselocked loop input and output amount polymerization front and back is constant, and control parameter is set still according to single VSC type STATCOM.Root According to the single grid-connected admittance model analytic value of VSC type STATCOM, then the harmonic voltage electric current of multiple VSC type STATCOM can after polymerizeing It is written as
λ is proportionality coefficient in formula, can obtain multiple grid-connected polymerization admittance model analytic value Y of VSC type STATCOMSTATCOMFor
Above formula shows grid-connected quantity n, the single VSC of multiple VSC type STATCOM grid-connected admittance and STATCOM in this programme The grid-connected admittance model of type STATCOM is related.It can be seen that from polymerization admittance model analytic expression, the grid-connected admittance of multiple VSC type STATCOM Model and the grid-connected admittance polymerization model of STATCOM are of equal value.This method meter and phaselocked loop, current loop control parameter, utilize single VSC Type STATCOM constructs the accurate admittance model of single machine grade, and it is grid-connected that multiple VSC type STATCOM are demonstrated from economics analysis formula The height equivalence of admittance polymerization model is incorporated into the power networks the quick calculating of admittance model convenient for multiple VSC type STATCOM.
C. meter and the grid side equivalent impedance of multiple VSC type STATCOM grid-connected admittance and line impedance
From multiple grid-connected admittance Y of VSC type STATCOMSTATCOMModel analyzing expression formula from the point of view of, meter and multiple VSC types When STATCOM is incorporated into the power networks, YSTATCOMNumerical value can not ignore.In order to carry out Accurate Model to grid side equivalent impedance, according to Impedance analysis is theoretical, Fig. 2 can abbreviation be Fig. 6.Wherein existing net side impedance model is reduced to equivalent circuit, network voltage source VgIt is converted into current source Ig, the numerical relation of grid-connected admittance model and existing electric network impedance model using VSC type STATCOM can ?
Y in formulageFor the form of admittance of grid side equivalent impedance, being write as impedance manner is
Z in formulageFor meter and the grid side equivalent impedance of multiple VSC type STATCOM operation.Existing grid side impedance model The frequency characteristic comparative analysis of frequency characteristic and meter and the grid side equivalent impedance model of the grid-connected admittance of multiple VSC type STATCOM See implementation example 1.
Implementation example 1:
Existing grid side impedance model only accounts for line impedance, fills in the reactive compensation containing multiple VSC type STATCOM When setting grid-connected, grid side impedance model changes therewith.According to the present invention scheme draw respectively existing grid side impedance model, The frequency characteristic of the grid side model of the grid-connected admittance model of VSC type STATCOM, meter and multiple VSC type STATCOM operation, By analyzing these three frequency characteristics, amendment of the present invention program to existing grid side impedance model is verified.Due to this hair Bright purpose is to provide the reference of grid side impedance operator for new-energy grid-connected stability problem, therefore only compares in implementation example Low frequency characteristic (0~130Hz) in frequency curve.
According to existing grid side equivalent impedance modeling method, line reactance is equivalent impedance model, grid side impedance Model response curve is as shown in Figure 7.Under logarithmic coordinates, the increase proportional to frequency of grid side impedance magnitude, phase in figure Position is constant.Using the analytical expression of the grid-connected admittance model of VSC type STATCOM, the grid-connected admittance model of VSC type STATCOM is drawn Frequency characteristic, as shown in figure 8, the frequency characteristic of grid-connected admittance has apparent wave between 30Hz~130Hz in figure It is dynamic.
Fig. 9 is the grid side impedance model frequency characteristic of meter and multiple VSC type STATCOM operation, compared with Fig. 7, It is almost consistent with existing grid side impedance model in 0~30Hz.After considering that multiple VSC type STATCOM are incorporated into the power networks, by VSC type The influence of STATCOM self-characteristic, grid side impedance model frequency characteristic are fluctuated in 30Hz~130Hz.Modulus of impedance The frequency characteristic of type shows: after meter and VSC type STATCOM are grid-connected, the grid side impedance model of the present invention program is in part Frequency range reduces the deviation of conventional model.
On the basis of a kind of above-mentioned grid side equivalent impedance modeling method, the present invention also provides a kind of equivalent resistances of grid side Anti- modeling, comprising:
It polymerize equivalent modules: single using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling Member, the grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model building module: it is led using grid-connected admittance model and the route of voltage-source type Static Var Compensator Receive model coupling and impedance relationship, establish the grid side equivalent impedance mould that runs containing multiple voltage-source type Static Var Compensator Type.
One skilled in the art will appreciate that in addition to realizing system provided by the invention in a manner of pure computer readable program code It, completely can be by the way that method and step be carried out programming in logic come so that the present invention provides and its other than each device, module, unit System and its each device, module, unit with logic gate, switch, specific integrated circuit, programmable logic controller (PLC) and embedding Enter the form of the controller that declines etc. to realize identical function.So system provided by the invention and its every device, module, list Member is considered a kind of hardware component, and to include in it can also for realizing the device of various functions, module, unit To be considered as the structure in hardware component;It can also will be considered as realizing the device of various functions, module, unit either real The software module of existing method can be the structure in hardware component again.
Specific embodiments of the present invention are described above.It is to be appreciated that the invention is not limited to above-mentioned Particular implementation, those skilled in the art can make a variety of changes or modify within the scope of the claims, this not shadow Ring substantive content of the invention.In the absence of conflict, the feature in embodiments herein and embodiment can any phase Mutually combination.

Claims (8)

1. a kind of grid side equivalent impedance modeling method characterized by comprising
It polymerize equivalent step: using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling unit, The grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model foundation step: the grid-connected admittance model and line admittance mould of voltage-source type Static Var Compensator are utilized The coupling of type and impedance relationship establish the grid side equivalent impedance model run containing multiple voltage-source type Static Var Compensator.
2. grid side equivalent impedance modeling method according to claim 1, which is characterized in that the polymerization equivalent step packet It includes:
Harmonic linear is carried out to the phaselocked loop of the small signal of voltage-source type Static Var Compensator, current loop control circuit in frequency domain Change, obtains current-responsive caused by grid disturbances under operating status using the result of harmonic linearization, and then calculate electricity The grid-connected admittance model of potential source type Static Var Compensator.
3. grid side equivalent impedance modeling method according to claim 2, which is characterized in that the polymerization equivalent step is also Include:
The grid-connected admittance model of n voltage-source type Static Var Compensator is polymerize equivalent, n voltage-source type static reactive The polymerization equivalence principle of device are as follows: the capacity of polymerization model is the summation of n voltage-source type Static Var Compensator, defeated after polymerization Electric current expands n times out;Filter inductance reduces n times;Current controller PI parameter reduces n times;Before the polymerization of phaselocked loop input and output amount Constant afterwards, control parameter is set still according to single voltage-source type Static Var Compensator.
4. grid side equivalent impedance modeling method according to claim 3, which is characterized in that the equivalent impedance model is built Vertical step includes:
Existing net side impedance model is reduced to equivalent circuit, network voltage source VgIt is converted into current source Ig, utilize multiple electricity The grid-connected admittance model analytic value Y of potential source type Static Var CompensatorSTATCOMNumerical relation with existing electric network impedance model can :
Y in formulageFor the form of admittance of grid side equivalent impedance, write as impedance manner are as follows:
Z in formulageFor meter and the grid side equivalent impedance of multiple voltage-source type Static Var Compensator operation.
5. a kind of grid side equivalent impedance modeling characterized by comprising
It polymerize equivalent modules: using the grid-connected admittance model of single voltage-source type Static Var Compensator as minimum modeling unit, The grid-connected admittance model polymerization of multiple voltage-source type Static Var Compensator is equivalent;
Equivalent impedance model building module: the grid-connected admittance model and line admittance mould of voltage-source type Static Var Compensator are utilized The coupling of type and impedance relationship establish the grid side equivalent impedance model run containing multiple voltage-source type Static Var Compensator.
6. grid side equivalent impedance modeling according to claim 5, which is characterized in that the polymerization equivalent modules packet It includes:
Harmonic linear is carried out to the phaselocked loop of the small signal of voltage-source type Static Var Compensator, current loop control circuit in frequency domain Change, obtains current-responsive caused by grid disturbances under operating status using the result of harmonic linearization, and then calculate electricity The grid-connected admittance model of potential source type Static Var Compensator.
7. grid side equivalent impedance modeling according to claim 6, which is characterized in that the polymerization equivalent modules are also Include:
The grid-connected admittance model of n voltage-source type Static Var Compensator is polymerize equivalent, n voltage-source type static reactive The polymerization equivalence principle of device are as follows: the capacity of polymerization model is the summation of n voltage-source type Static Var Compensator, defeated after polymerization Electric current expands n times out;Filter inductance reduces n times;Current controller PI parameter reduces n times;Before the polymerization of phaselocked loop input and output amount Constant afterwards, control parameter is set still according to single voltage-source type Static Var Compensator.
8. grid side equivalent impedance modeling according to claim 7, which is characterized in that the equivalent impedance model is built Formwork erection block includes:
Existing net side impedance model is reduced to equivalent circuit, network voltage source VgIt is converted into current source Ig, utilize multiple electricity The grid-connected admittance model analytic value Y of potential source type Static Var CompensatorSTATCOMNumerical relation with existing electric network impedance model can :
Y in formulageFor the form of admittance of grid side equivalent impedance, write as impedance manner are as follows:
Z in formulageFor meter and the grid side equivalent impedance of multiple voltage-source type Static Var Compensator operation.
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Cited By (2)

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CN110556854A (en) * 2019-08-12 2019-12-10 全球能源互联网研究院有限公司 Static harmonic analysis method and system for grid-connected point of flexible direct-current power transmission system
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