CN109586273A - Sub-synchronous oscillation appraisal procedure and system based on wind energy HVDC delivery system - Google Patents
Sub-synchronous oscillation appraisal procedure and system based on wind energy HVDC delivery system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
- H02J2003/365—Reducing harmonics or oscillations in HVDC
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
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- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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Abstract
The present invention provides sub-synchronous oscillation appraisal procedures and system based on wind energy HVDC delivery system, including building electric power system model based on the generating set model, farm model and HVDC circuit model that pre-establish；Based on electric power system model, subsynchronous oscillation of electrical power system risk is calculated.Assessment invention increases wind power plant to HVDC system generation sub-synchronous oscillation, expand the application range of original standard, more meet the actual conditions of current electric grid, it realizes when considering that HVDC conveys extensive wind energy, whether the complicated electric power system occurs the entry evaluation of sub-synchronous oscillation, large-scale wind electricity base and the HVDC influence caused by electric system can effectively be analyzed, can more accurately assessment system occur sub-synchronous oscillation a possibility that, have great significance to actual safe and stable operation of power system.
Description
Technical field
The invention belongs to Power System Planning and running technology field, in particular to based on wind energy HVDC delivery system
Sub-synchronous oscillation appraisal procedure and system.
Background technique
The characteristics of Base environment is gradually presented with the fast development of last decade in wind-powered electricity generation, scale, with load contrary distribution
Problem is than more serious.Since wind power resources integrated distribution is in economically underdeveloped area, wind energy this area of production can not all disappear
It receives, can only send outside to developed area, wind-powered electricity generation conveys contradiction than more prominent.D.C. high voltage transmission HVDC technology can be remote because of it
The characteristics of distance, loss small transmission of large capacity electric energy and by favor, but large capacity, remote energy transmission are to power grid
Stable operation is brought the problem of some column, and sub-synchronous oscillation is exactly one of them more distinct issues.Further, since extensive
The access of the large-capacity powers electronic equipment such as wind-powered electricity generation and HVDC, greatly changes the performance of power grid, so that sub-synchronous oscillation is asked
Topic shows new feature.In order to ensure the stable operation of power grid, need to receive the angle of wind-powered electricity generation capacity to send out system from system
The risk of raw sub-synchronous oscillation is assessed.
Currently, national standard GB/Z 20996.3 and IEC/TR 60919-3 standard give for HVDC access power grid and quantitatively comment
Estimate index, by the degree of strength that interacts between assessment generating set and HVDC system, filters out most strong with the HVDC degree of association
Generating set, come judge between generating set and HVDC occur sub-synchronous oscillation risk size, the standard since it is desired that
Capacity parameter is easy to get, and is compared and is suitble to use in the assessment planning at engineering construction initial stage.
But current, for large-scale wind power, by the sub-synchronous oscillation risk of HVDC conveying electric energy, there is presently no corresponding
Assess foundation.
Summary of the invention
To overcome above-mentioned the prior art does not consider that large-scale wind electricity base is to the sub-synchronous oscillation of the electric system containing HVDC
Influence it is insufficient, the present invention proposes a kind of sub-synchronous oscillation appraisal procedure and system based on wind energy HVDC delivery system.
Realize solution used by above-mentioned purpose are as follows:
A kind of sub-synchronous oscillation appraisal procedure based on wind energy HVDC delivery system, thes improvement is that:
Electric power system model is built based on the generating set model, farm model and HVDC circuit model pre-established；
Based on the electric power system model, subsynchronous oscillation of electrical power system risk is calculated.
First optimal technical scheme provided by the invention, it is improved in that described build electric power system model and institute
It states and calculates between subsynchronous oscillation of electrical power system risk, further includes:
Based on the electric power system model, the generator under wind power plant short-circuit conditions with sub-synchronous oscillation risk is selected
Group.
Second optimal technical scheme provided by the invention, it is improved in that described based on the generator pre-established
Group model, farm model and HVDC circuit model build electric power system model and include:
Increase after the farm model and the HVDC circuit model are combined according to the actual condition of transmission line of electricity
Add generating set model；
The farm model uses two close cycles PI control model, comprising: open sea wharf and inner ring current control；
The HVDC circuit model is built according to the control strategy of HVDC and the parameter of protective module.
Third optimal technical scheme provided by the invention, it is improved in that under the selection wind power plant short-circuit conditions
Generating set with sub-synchronous oscillation risk, comprising:
The UIF value of generating set under wind power plant short-circuit conditions is calculated using unit function coefficient method；
Selecting generating set of the UIF value greater than 0.1 is the generating set with sub-synchronous oscillation risk.
4th optimal technical scheme provided by the invention, it is improved in that the application unit function coefficient method meter
Calculate the UIF value such as following formula of generating set under wind power plant short-circuit conditions:
UIFi=SHVDC/Si[1-SCi/SCTOT]2 (1)
Wherein, UIFiFor the UIF value of i-th generator, SHVDCFor the rated capacity of D.C. high voltage transmission, SiIt is sent out for i-th
The rated capacity of motor, SCiRefer to the three-phase shortcircuit capacity at HVDC Inverter Station ac bus, is not wrapped when calculating the capacity of short circuit
The contribution of i-th generating set is included, while also not including the effect of alternating current filter, SCTOTRefer to HVDC converting plant ac bus
Place includes the three-phase shortcircuit capacity of i-th generating set contribution, does not consider the effect of alternating current filter when calculating the capacity of short circuit.
5th optimal technical scheme provided by the invention, it is improved in that the SCiAnd SCTOTCalculation method
Are as follows:
Using the electric power system model, using time-domain-simulation, by calculating system short-circuit under Wind turbines short-circuit conditions
The method of capacity calculates the electric power system model within the scope of 5~45Hz, SCiAnd SCTOTValue.
6th optimal technical scheme provided by the invention, it is improved in that the subsynchronous oscillation of electrical power system wind
Danger such as following formula:
W=SHVDC/Swind[1-SCwind/SCTOT-wind]2 (2)
Wherein, W is subsynchronous oscillation of electrical power system risk assessment index, SHVDCFor the rated capacity of D.C. high voltage transmission,
SwindFor the rated capacity of wind power plant, SCwindFor the three-phase shortcircuit capacity at HVDC converting plant ac bus, short circuit appearance is calculated
Do not include the capacity of generating set when amount, while not including the effect of alternating current filter, SC yetTOT-windFor the exchange of HVDC converting plant
Include the three-phase shortcircuit capacity of generating set contribution at bus, includes the effect of wind power plant when calculating the capacity of short circuit.
7th optimal technical scheme provided by the invention, it is improved in that the SCwindAnd SCTOT-windCalculating
Method are as follows:
Held using time-domain-simulation by computing system short circuit using the D.C. high voltage transmission HVDC delivery system model
The method of amount calculates the electric power delivery system model within the scope of 5~45Hz, SCwindAnd SCTOT-windValue.
A kind of sub-synchronous oscillation assessment system based on wind energy HVDC delivery system, it is improved in that including electric power
System modeling module and Study of Risk Evaluation Analysis for Power System module；
The power system modeling module is used for based on the generating set model, farm model and HVDC line pre-established
Road model buildings electric power system model；
The Study of Risk Evaluation Analysis for Power System module is for subsynchronous oscillation of electrical power system risk after calculating.
8th optimal technical scheme provided by the invention, it is improved in that further including generating set risk assessment mould
Block；
The generating set risk evaluation module is used to be based on the electric power system model, selects under wind power plant short-circuit conditions
Generating set with sub-synchronous oscillation risk.
9th optimal technical scheme provided by the invention, it is improved in that the power system modeling module includes
Farm model subelement, HVDC circuit model subelement and electric power system model subelement；
The HVDC circuit model subelement is used to build HVDC according to the control strategy of HVDC and the parameter of protective module
Circuit model；
The farm model subelement uses two close cycles PI control model, comprising: open sea wharf and interior circular current
Control；
The electric power system model subelement is used for the farm model and the HVDC circuit model according to transmission of electricity
The actual condition of route increases generating set model after being combined.
Compared with the immediate prior art, the excellent effect that the present invention has is as follows:
The present invention is to increase wind on the basis of original assessment generating set and HVDC system interaction degree of strength
Electric field connects the assessment that sub-synchronous oscillation system occurs after people, expands the application range of original standard, more meets current electricity
The actual conditions of net are realized when considering that HVDC conveys extensive wind energy, whether which are occurred secondary
The entry evaluation of synchronized oscillation can effectively analyze large-scale wind electricity base and the HVDC influence caused by electric system, can be more
Accurately a possibility that sub-synchronous oscillation, occurs for assessment system, there is important meaning to actual safe and stable operation of power system
Justice.
The frequency range that present invention combination sub-synchronous oscillation occurs, increases the examination under different frequency scope to index,
Keep index value more comprehensive and accurate.
The present invention compares double-fed fan motor unit and equivalent electricity of the directly driven wind-powered unit in the case where sub-synchronous oscillation frequency occurs
The difference that sub-synchronous oscillation mechanism occurs for the two is evaded on road, from the phenomenon that causing, is proposed the index, is made it have extensively
Applicability.
Detailed description of the invention
Fig. 1 is that a kind of process of the sub-synchronous oscillation appraisal procedure based on wind energy HVDC delivery system provided by the invention is shown
It is intended to；
Fig. 2 is rotor-side frequency converter RSC typical case's control block diagram；
Fig. 3 is provided by the invention a kind of based on wind energy HVDC delivery system simplified model schematic diagram；
Fig. 4 is a kind of sub-synchronous oscillation methods of risk assessment apoplexy based on wind energy HVDC delivery system provided by the invention
Subsynchronous oscillation of electrical power system computation model schematic diagram under electric field short-circuit conditions；
Fig. 5 is double-fed fan motor unit power frequency equivalent circuit schematic diagram；
Fig. 6 is the equivalent circuit under the subsynchronous frequency fssr of double-fed fan motor unit；
Fig. 7 is HVDC delivery system system simulation model topology diagram.
Specific embodiment
There are mainly three types of dividing according to Wind turbines initiation sub-synchronous oscillation phenomenon: IGE (induction generator
Effect, IGE), SSCI (subsynchronous control interaction, SSCI) and SSTI
Three kinds of (subsynchronous torsional interaction, SSTI).Theoretically in addition to magneto alternator group does not have
There is shafting system, can exclude completely outside SSTI phenomenon, Wind turbines are because the construction of itself blower shafting is so that shafting is turned round naturally
Vibration frequency is lower, so that the route series compensation degrees for causing sub-synchronous oscillation are higher, up to 70% or more, is less likely in actual circuit
There are so high series compensation degrees, so SSTI phenomenon is generally not as research emphasis.IGE phenomenon be under a certain frequency system etc.
When effect impedance value is negative value, the lasting diverging of line current under secondary frequencies can be caused even to will increase；SSCI phenomenon is wind turbine
What group caused, the pure electrical resonance unrelated with generator unit shaft system system is joined with blower access capacity, wind speed, frequency converter
It counts related with factors such as line topological parameters.Studies have shown that SSCI be because frequency converter of wind power unit control system participation and
The sub-synchronous oscillation phenomenon of initiation is when having oscillating component in the line, in rectification and the reversals for passing through fan frequency converter
Afterwards, it generates new oscillating current to form positive feedback with original current perturbation and constantly increase, then it is assumed that sub-synchronous oscillation phenomenon hair
It is raw.SSCI part generation " path " is overlapped with IGE phenomenon, is that IGE phenomenon passes through the effect after frequency converter of wind power unit acts on.
Since wind energy is larger in partial electric grid proportion, SSCI is distinctive a kind of oscillation form after wind power integration, so this patent
It is when progress sub-synchronous oscillation model is equivalent, the function and effect of fan frequency converter are equivalent into blower model emulation.
Because being completely to be electrically connected with electric system, total power Frequency Converter Control hinders magneto alternator group completely
Broken blower and the direct electrical link of power grid, and the mechanism study that sub-synchronous oscillation occurs in it is not very perfect, and existing research is general
It is equivalent to be regarded as negative impedance progress, and it is close to think that magneto alternator generation sub-synchronous oscillation problem has with its external electrical network
The relationship cut, thus it is similar with double-fed fan motor unit equivalent also being used to permanent-magnet synchronous Wind turbines, and double-fed fan motor machine
Group is wider in China's application, and for the popularity for guaranteeing application, this patent is equivalent as Wind turbines using double-fed fan motor unit
Universal model.
Existing research shows that HVDC contacted in AC network with Turbo-generator Set very weak, HVDC converting plant with
Between the Turbo-generator Set distance it is close and conveying rated power and the Turbo-generator Set rated power same
On the order of magnitude, the probability that HVDC causes sub-synchronous oscillation is higher.Trace it to its cause is because of the fast of HVDC own power electronic device
Fast turn-off capacity can make quick reaction for the disturbance in electric system, can have enhancing to disturbance under certain conditions
Effect and cause the sub-synchronous oscillation phenomenon of system.
In order to just avoid causing the condition vibrated establishment as far as possible in the construction plan stage, HVDC is occurred in national standard subsynchronous
Oscillation provides a screening index.Data needed for this screening index are less, can be simply and effectively by investigating capacity of short circuit
Method come filter out power grid using HVDC cause sub-synchronous oscillation a possibility that.But the index, which does not account for large-scale wind electricity, to be connect
Enter the influence caused by power grid, can no longer meet the actual demand of current electric grid, so needing to carry out existing evaluation index
It is perfect.
Wind turbines cause sub-synchronous oscillation phenomenon using HVDC route conveying wind energy also generation in practice, how right
System sub-synchronous oscillation occurrence risk proposes easy method to assess be a critical problem.HVDC and Wind turbines cause secondary
The principle of synchronized oscillation is different, so New Set needs comprehensive two sub-synchronous oscillations of HVDC and Wind turbines to cause factor.
Further, since Wind turbines are the generators for having Frequency Converter Control, the power of output is by Frequency Converter Control, with conventional hair
Motor group is different, so carrying out being also required to consider Wind turbines and the feature of generating set respectively when model is equivalent.
A specific embodiment of the invention is described in further detail with reference to the accompanying drawing.
Sub-synchronous oscillation appraisal procedure process proposed by the present invention based on wind energy HVDC delivery system is as shown in Figure 1, packet
It includes
Step 1 builds electric system based on the generating set model, farm model and HVDC circuit model pre-established
Model；
Step 2 is based on the electric power system model, calculates subsynchronous oscillation of electrical power system risk.
Further, step 1 includes:
1-1, the control module for selecting Wind turbines, build the generalization model of Wind turbines；
Since the inertia coeffeicent of double-fed fan motor unit shafting is lower, need there are very high series compensation degrees to be possible to draw on circuit
Sub-synchronous oscillation is sent out, the probability that such case occurs in actual power grid is lower, and also there is no wind in actual items
The example of electric shaft system of unit oscillation, to Wind turbines shafting not as primary study, so Wind turbines shafting uses two mass
Block models simulation.
The Frequency Converter Control of wind turbine model use compared with frequently with two close cycles PI control model, respectively exterior ring power
Control and inner ring current control, the function of rotor-side frequency converter are mainly the decoupling control realized to active power and reactive power
System, the major function of net side frequency converter are to maintain the stabilization of frequency converter DC voltage, and in this patent, net side frequency converter does not do imitative
Very.Rotor-side frequency converter typical case control is as shown in Fig. 2.Due to the limitation of research, the crowbar protection of Wind turbines, mistake
Voltage protection etc. is also not as the research contents of this patent.
1-2, according to the control strategy of HVDC and the parameter of protective module, build HVDC circuit model；
The controller of HVDC route, in rectification side using circuit control strategy is determined, inverter side, which uses, determines gamma kick
To guarantee commutation success.It is all made of existing classic control module parameter, I will not elaborate.
1-3, by the generalization model of the Wind turbines and the HVDC circuit model according to the practical need of transmission line of electricity
It is combined, and increases generating set model, form HVDC delivery system model.
During HVDC delivery system model buildings, increase generating set model, and by farm model and HVDC line
Road model is combined according to the actual needs of route.It is as shown in Fig. 3 that HVDC delivery system conveys model simplification figure.
Existing research shows that the small interference that the reason of HVDC initiation sub-synchronous oscillation is primarily due to electric system is quick
Caused by reaction, so can be using the interaction of HVDC and generating set as main production in carrying out sub-synchronous oscillation research
Reason is given birth to study.Double-fed asynchronous Wind turbines are substantially the asynchronous electricity that rotor-side has installed electronic frequency convertor control additional
Machine, stator and rotor are to realize flexible synchronous by the control of electronic frequency convertor；Directly driven wind-powered unit is using total power
Frequency converter is isolated by synchronous machine with power grid, and the power of output is controlled using total power frequency converter；Its wind on other occasions
Negative resistance character is presented in machine equivalent impedance, the unstable of system is caused, to cause the sub-synchronous oscillation phenomenon of system, so wind
The addition of machine will increase the risk that sub-synchronous oscillation occurs for system in some cases.
Wind turbines cause the sub-synchronous oscillation and wind that the mechanism of sub-synchronous oscillation is different, and Wind turbines occur from generator
The shafting of motor group is not related, is a kind of pure electrical oscillation, and the sub-synchronous oscillation that generating set generates is the vibration in system
It swings and is overlapped with generator shafting natural mode and causes.Secondly, the operation mechanism of Wind turbines and common generating set is not
Together, Wind turbines are the motors using Frequency Converter Control, and the active and reactive power of output can be adjusted by frequency converter to be realized
Decoupling control.Because the sub-synchronous oscillation of Wind turbines shows the characteristic different from common generating set, carrying out
The two is separated into consideration in sub-synchronous oscillation assessment.
IEC/TR 60919-3 standard, which gives, is quantitatively evaluated generating set and HVDC system interaction degree of strength
Numerical indication, that is, find out with the strongest generating set of the HVDC degree of association, calculate the relevance between this generating set and HVDC,
If coupling index is below 0.1, then it is assumed that this generating set does not interact significantly with HVDC system, does not need pair
This generating set carries out sub-synchronous oscillation research, conversely, then there may be sub-synchronous oscillation risk, need to carry out deeper into
Research.
Between step 1 and step 2 further include: be based on the electric power system model, select to have under wind power plant short-circuit conditions
There is the generating set of sub-synchronous oscillation risk.Specifically:
It is screened using generating set of the unit function coefficient method UIF to the HVDC delivery system model, UIF value is big
Generating set in 0.1 has sub-synchronous oscillation risk；
Under Wind turbines short-circuit conditions, HVDC delivery system is equivalent to generating set is equivalent to G shown in attached drawing 4i
With G two parts, wherein GiFor i-th unit, at this point, other units are equivalent to G.According to attached drawing 4, i-th unit is calculated
To the unit function coefficient UIF of HVDCiAre as follows:
UIFi=SHVDC/Si[1-SCi/SCTOT]2 (1)
Wherein, SHVDCRefer to the rated capacity of D.C. high voltage transmission, unit: MVA；
SiRefer to the rated capacity of i-th generator, unit: MVA；
SCiRefer to the three-phase shortcircuit capacity at HVDC Inverter Station ac bus, does not include i-th when calculating the capacity of short circuit
The contribution of generating set, while also not including the effect of alternating current filter, unit: MVA；
SCTOTRefer to include at HVDC converting plant ac bus i-th generating set contribution three-phase shortcircuit capacity, calculate
The effect of alternating current filter, unit: MVA are not considered when the capacity of short circuit.
If UIF at this timei< 0.1, then it is assumed that unit i and HVDC system does not interact significantly, but because does not examine
The effect for considering Wind turbines, so also step 3 is needed to distinguish again；It is on the contrary then need further to verify subsynchronous concussion risk.
This step is screening early period, selects itself big generating set of sub-synchronous oscillation risk before wind power plant accesses.If generating set
The subsynchronous risk of itself is big, illustrates that the unit region is not suitable for increasing wind power plant, it is proposed that separately addressing or change are local
Electric network composition.
UIF can be expressed as to the form of system equivalent impedance according to formula (3) according to attached drawing 4,
S=U2/Z (3)
Wherein, S represents power, and Z represents the impedance of the branch；
Formula (1) can be equivalent to
UIFi=SHVDC/Si[1-(Zi//ZGi)/ZGi]2 (4)
Wherein, ZiFor the equivalent impedance of i-th generator, ZGiFor the equivalent of remaining generating set in addition to the i-th generator
Impedance, Zi//ZGiIndicate ZiWith ZGiImpedance value after parallel connection.
In actually calculating, it is contemplated that the equivalent impedance of generator can not obtain easily, and in order to realize to system
Comprehensive investigation of sub-synchronous oscillation frequency, using system short circuit capacity under calculating different frequency in sub-synchronous oscillation risk assessment
Method realize.Using D.C. high voltage transmission HVDC delivery system model under Wind turbines short-circuit conditions, i.e., by such as Fig. 4
Shown in model different frequency (5 by the method for computing system capacity of short circuit, constantly calculated using the method for time-domain-simulation
~45Hz) under SCiAnd SCTOTValue, and then by formula (1) calculate UIFi。
Step 2 includes:
Calculate the risk of the HVDC delivery system sub-synchronous oscillation after large-scale wind electricity base is accessed, sub-synchronous oscillation risk
Evaluation index W needs to carry out sub-synchronous oscillation research when being greater than 0.1.
Equivalent circuit of the 2-1 Wind turbines under sub-synchronous oscillation frequency:
Attached drawing 5 is double-fed fan motor unit in power frequency equivalent circuit.From attached drawing 5 as can be seen that the equivalent circuit turns blower
The equivalent characteristic for arriving stator side, reflecting double-fed fan motor unit i.e. and have as power supply in sub- side, and have the characteristic as asynchronous machine.
Power grid rated frequency is f=50Hz, RrAnd XrRespectively rotor side resistance and reactance, RsAnd XsRespectively stator side resistance and electricity
It is anti-, XmFor rotor mutual inductance equivalent reactance.Assuming that frequency when sub-synchronous oscillation occurs for system is fssr, frequency range is generally 5
~45Hz.
Rotor-side frequency converter typical case's control block diagram shown in 2 with reference to the accompanying drawings, double-fed fan motor unit are real by two-stage PI control
Now to the control of the decoupling control and output voltage of active power and reactive power；The control block diagram be divided into power outer loop control and
Current inner loop control ignores exterior ring power control since the reaction speed of power outer loop control is greater than the speed of current control inner ring
System only considers inner ring current control.In the control block diagram, PrefAnd QrefThe respectively reference value of active power and reactive power,
Id and iq is that electric current is divided into input dq shaft current amount, UrdAnd UrqFor UrVoltage after voltage dq decoupler shaft, kpdAnd kidFor d
The proportionality coefficient and integral coefficient of axis PI control；kpqAnd kiqFor the proportionality coefficient and integral coefficient of q axis PI control.
It intercepts double-fed fan motor unit to occur in the sub-synchronous oscillation very short current oscillation time, it is assumed that double-fed fan motor unit turns
There is Δ i in sub- siderCurrent disturbing ignore power outer loop control after attached rotor-side Frequency Converter Control shown in Fig. 2
Effect, can obtain rotor voltage UrFluctuation Δ UrIt indicates, is shown below.
ΔUr=-KpΔir+ΔUr′ (5)
In formula, KpK for the proportionality coefficient of rotor-side frequency converter RSC current control, in respective figure 2pdAnd kpqVector.Δ
Ur' for the variation of output voltage caused by cross decoupling item and integration control etc., this patent is ignored.
Pass through simplification, it can be deduced that:
Kp=-Δ Ur/Δir (6)
Assuming that it is f that revolving speed, which generates the sub-synchronous oscillation frequency that Δ ω disturbance generates,ssr, then it can be concluded that sub-synchronous oscillation frequency
The equivalent circuit of double-fed fan motor unit under rate, as shown in Fig. 6.
In sub-synchronous oscillation frequency fssrUnder, since double-fed fan motor unit is asynchronous machine, then rotor slippage SssrIt can be with table
It is shown as:
Sssr=(fssr-fr)/fssr (7)
Wherein, frFor rotor frequency, because of fssr<fr, so Sssr<0。
Additional description is needed,
X=j ω L；The π of ω=2 f
In above formula, X represents line reactance, and ω is angular speed, and f is frequency, and L represents line inductance.
So having: X=F (f)=j2 π fL, X is the function of frequency.
So according to attached drawing 6, in sub-synchronous oscillation frequency fssrUnder, the equivalent impedance of the external equivalent circuit of wind power plant
Zeq_ssrAre as follows:
Zeq_ssr=(R+KP)/Sssr+jfssrXr+(Zs_ssr//(jfssr Xm)) (8)
Zs_ssr=Rs+jfssrXs (9)
In formula, Zs_ssr//(jfssr Xm) mean ZsWith XmValue after parallel connection calculates under sub-synchronous oscillation frequency.
Re [Z at this timeeqssr] be negative value, be the equal of negative resistance, system be at this time it is unstable, this may result in line
The lasting diverging oscillation of road electric current.Wherein, KP/SssrIt is double-fed fan motor unit when sub-synchronous oscillation occurs, rotor-side frequency converter
Effect partial, in fssrThis lower value is negative, and is equivalent to power supply.In view of the electrical relation SC between capacity of short circuit and equivalent impedance
=U2/ Z, it is believed that be all the function of frequency using capacity of short circuit and equivalent impedance, and system short circuit capacity is easier to pass through
Software emulation obtains.
The assessment derivation of equation under 2-2 double-fed fan motor unit sub-synchronous oscillation frequency:
It is same by using for reference synchronous motor initiation time because of a kind of asynchronous generator of the double-fed fan motor unit as flexible synchronous
The engineering reasonability for walking oscillation, in conjunction with the characteristics of Wind turbines itself, the HVDC after proposing Wind turbines access transmits electric power
The sub-synchronous oscillation criterion of system.The index of sub-synchronous oscillation risk assessment at this time W may be expressed as: using impedance manner
W=SHVDC/Swind[1-(Zeq//ZG)/ZG]2 (10)
In formula, ZeqFor the external equivalent impedance of Wind turbines；ZGFor generator equivalent impedance.
According to attached drawing 3, formula (4) and formula (8) are it is found that because ZeqIt is negative under sub-synchronous oscillation frequency, i.e. Zeq_ssr<
0, it will cause [1- (Zeq//ZG)/ZG]2>1。
The stability criterion of reference formula (4) is it is found that if UIFiThe risk that sub-synchronous oscillation occurs for > 0.1 system is larger, root
The relativeness of each electrical quantity when accordingly, can be derived from, and in W > 0.1, then the wind of sub-synchronous oscillation occurs for whole system
Danger is larger, needs to carry out additional analytical calculation.
The directly driven wind-powered unit considered also can be equivalent to the form of Power supply belt negative resistance, institute under sub-synchronous oscillation frequency
There is similar conclusion for formula (10).So sub-synchronous oscillation risk assessment index W has broad applicability.
Assessment under 2-3 Wind turbines sub-synchronous oscillation frequency:
The equivalent impedance of the systems such as equivalent impedance, the equivalent impedance of generator in view of Wind turbines can not obtain easily
, and in order to realize comprehensive investigation to the sub-synchronous oscillation frequency of system, using calculating in sub-synchronous oscillation risk assessment
The method of system short circuit capacity is realized under different frequency.
Sub-synchronous oscillation wind occurs to investigate large-scale wind electricity unit comprehensively by the system that HVDC Transmission Corridor conveys wind energy
The assessment of danger, takes precautions against the generation of sub-synchronous oscillation, as shown in Fig. 7, imitative using time domain by building power system simulation model
Very, by the method for computing system capacity of short circuit, by the method for computing system capacity of short circuit, constantly 5~45Hz is calculated not
Sub-synchronous oscillation evaluation index under same frequency.
Wind turbines sub-synchronous oscillation risk assessment index are as follows:
W=SHVDC/Swind[1-SCwind/SCTOT-wind]2 (2)
SHVDCRefer to the rated capacity of D.C. high voltage transmission, unit: MVA；
SwindRefer to the rated capacity of Wind turbines, unit: MVA；
SCwindRefer to the three-phase shortcircuit capacity at HVDC converting plant ac bus, does not include hair when calculating the capacity of short circuit
The capacity of motor group, while also not including the effect of alternating current filter, unit: MVA；
SCTOT-windRefer to include at HVDC converting plant ac bus generating set contribution three-phase shortcircuit capacity, calculate should
The effect of Wind turbines, unit: MVA are considered when capacity of short circuit；
Within the scope of 5~45Hz, scanning calculates SCwindAnd SCtot-windValue, work as W > 0.1, it is believed that system can occur at this time
Sub-synchronous oscillation is very big, needs further to further investigate, as space is limited, this patent does not illustrate.
According to same inventive concept, the present invention also provides a kind of sub-synchronous oscillations based on wind energy HVDC delivery system to comment
Estimate system, including power system modeling module and electric system danger evaluation module；
The power system modeling module is used for based on the generating set model, farm model and HVDC line pre-established
Road model buildings electric power system model；
The Study of Risk Evaluation Analysis for Power System module is for calculating subsynchronous oscillation of electrical power system risk.
Further, which further includes generating set risk evaluation module；
The generating set risk evaluation module is used to be based on the electric power system model, selects under wind power plant short-circuit conditions
Generating set with sub-synchronous oscillation risk.
Further, power system modeling module includes farm model subelement, HVDC circuit model subelement and electric power
System model subelement；
The HVDC circuit model subelement is used to build HVDC according to the control strategy of HVDC and the parameter of protective module
Circuit model；
The farm model subelement uses two close cycles PI control model, comprising: open sea wharf and interior circular current
Control；
The electric power system model subelement is used for the farm model and the HVDC circuit model according to transmission of electricity
The actual condition of route increases generating set model after being combined.
Finally it should be noted that: above embodiments are merely to illustrate the technical solution of the application rather than to its protection scopes
Limitation, although the application is described in detail referring to above-described embodiment, those of ordinary skill in the art should
Understand: those skilled in the art read the specific embodiment of application can still be carried out after the application various changes, modification or
Person's equivalent replacement, but these changes, modification or equivalent replacement, are applying within pending claims.
Claims (11)
1. a kind of sub-synchronous oscillation appraisal procedure based on wind energy HVDC delivery system, it is characterised in that:
Electric power system model is built based on the generating set model, farm model and HVDC circuit model pre-established；
Based on the electric power system model, subsynchronous oscillation of electrical power system risk is calculated.
2. the method as described in claim 1, which is characterized in that described to build electric power system model and the calculating electric system
Between sub-synchronous oscillation risk, further includes:
Based on the electric power system model, the generating set under wind power plant short-circuit conditions with sub-synchronous oscillation risk is selected.
3. the method as described in claim 1, which is characterized in that described based on the generating set model pre-established, wind power plant
Model and HVDC circuit model build electric power system model and include:
Increase hair after the farm model and the HVDC circuit model are combined according to the actual condition of transmission line of electricity
Motor group model；
The farm model uses two close cycles PI control model, comprising: open sea wharf and inner ring current control；
The HVDC circuit model is built according to the control strategy of HVDC and the parameter of protective module.
4. method according to claim 2, which is characterized in that have sub-synchronous oscillation under the selection wind power plant short-circuit conditions
The generating set of risk, comprising:
The UIF value of generating set under wind power plant short-circuit conditions is calculated using unit function coefficient method；
Selecting generating set of the UIF value greater than 0.1 is the generating set with sub-synchronous oscillation risk.
5. method as claimed in claim 4, which is characterized in that the application unit function coefficient method calculates wind power plant short circuit feelings
The UIF value such as following formula of generating set under condition:
UIFi=SHVDC/Si[1-SCi/SCTOT]2 (1)
Wherein, UIFiFor the UIF value of i-th generator, SHVDCFor the rated capacity of D.C. high voltage transmission, SiFor i-th generator
Rated capacity, SCiRefer to the three-phase shortcircuit capacity at HVDC Inverter Station ac bus, does not include when calculating the capacity of short circuit
The contribution of i platform generating set, while also not including the effect of alternating current filter, SCTOTRefer to and is wrapped at HVDC converting plant ac bus
The three-phase shortcircuit capacity for including the contribution of i-th generating set, does not consider the effect of alternating current filter when calculating the capacity of short circuit.
6. method as claimed in claim 5, which is characterized in that the SCiAnd SCTOTCalculation method are as follows:
Using the electric power system model, using time-domain-simulation, by calculating system short circuit capacity under Wind turbines short-circuit conditions
Method, calculate the electric power system model within the scope of 5~45Hz, SCiAnd SCTOTValue.
7. the method as described in claim 1, which is characterized in that the calculating subsynchronous oscillation of electrical power system risk such as following formula:
W=SHVDC/Swind[1-SCwind/SCTOT-wind] 2 (2)
Wherein, W is subsynchronous oscillation of electrical power system risk assessment index, SHVDCFor the rated capacity of D.C. high voltage transmission, SwindFor
The rated capacity of wind power plant, SCwindFor the three-phase shortcircuit capacity at HVDC converting plant ac bus, when calculating the capacity of short circuit not
Capacity including generating set, while also not including the effect of alternating current filter, SCTOT-windAt HVDC converting plant ac bus
Three-phase shortcircuit capacity including generating set contribution, includes the effect of wind power plant when calculating the capacity of short circuit.
8. the method for claim 7, which is characterized in that the SCwindAnd SCTOT-windCalculation method are as follows:
Using the electric power system model, the electric power is calculated by the method for computing system capacity of short circuit using time-domain-simulation
System model is within the scope of 5~45Hz, SCwindAnd SCTOT-windValue.
9. a kind of sub-synchronous oscillation assessment system based on wind energy HVDC delivery system, which is characterized in that including power train construction in a systematic way
Mould module and Study of Risk Evaluation Analysis for Power System module；
The power system modeling module is used for based on the generating set model, farm model and HVDC route mould pre-established
Type builds electric power system model；
The Study of Risk Evaluation Analysis for Power System module is used to be based on the electric power system model, calculates subsynchronous oscillation of electrical power system wind
Danger.
10. system as claimed in claim 9, which is characterized in that further include generating set risk evaluation module；
The generating set risk evaluation module is used to be based on the electric power system model, selects to have under wind power plant short-circuit conditions
The generating set of sub-synchronous oscillation risk.
11. system as claimed in claim 9, which is characterized in that the power system modeling module includes farm model
Unit, HVDC circuit model subelement and electric power system model subelement；
The HVDC circuit model subelement is used to build HVDC route according to the control strategy of HVDC and the parameter of protective module
Model；
The farm model subelement uses two close cycles PI control model, comprising: open sea wharf and inner ring current control；
The electric power system model subelement is used for the farm model and the HVDC circuit model according to transmission line of electricity
Actual condition be combined after increase generating set model.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110138009A (en) * | 2019-05-30 | 2019-08-16 | 国家电网公司西北分部 | A kind of HVDC transmission system simulation model sent outside with large-scale wind power |
| CN113852101A (en) * | 2021-09-26 | 2021-12-28 | 广东电网有限责任公司 | Method and device for determining risk of causing subsynchronous torsional vibration of steam turbine generator unit |
| CN114362210A (en) * | 2022-01-12 | 2022-04-15 | 全球能源互联网研究院有限公司 | Wind power plant oscillation risk assessment testing method, avoiding method and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104104097A (en) * | 2014-08-07 | 2014-10-15 | 国网吉林省电力有限公司 | Method for evaluating sub-synchronous oscillation of sending out system of wind power generation set |
| CN104578044A (en) * | 2015-01-14 | 2015-04-29 | 国网宁夏电力公司电力科学研究院 | Method for determining unit action coefficient based on subsynchronous oscillation analysis |
| EP3154147A1 (en) * | 2015-10-07 | 2017-04-12 | Siemens Aktiengesellschaft | Method and control device for controlling a power grid |
-
2017
- 2017-09-29 CN CN201710906443.0A patent/CN109586273A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104104097A (en) * | 2014-08-07 | 2014-10-15 | 国网吉林省电力有限公司 | Method for evaluating sub-synchronous oscillation of sending out system of wind power generation set |
| CN104578044A (en) * | 2015-01-14 | 2015-04-29 | 国网宁夏电力公司电力科学研究院 | Method for determining unit action coefficient based on subsynchronous oscillation analysis |
| EP3154147A1 (en) * | 2015-10-07 | 2017-04-12 | Siemens Aktiengesellschaft | Method and control device for controlling a power grid |
Non-Patent Citations (1)
| Title |
|---|
| 吕敬 等: "大型双馈风电场经MMC-HVDC并网的次同步振荡及其抑制", 《中国电机工程学报》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110138009A (en) * | 2019-05-30 | 2019-08-16 | 国家电网公司西北分部 | A kind of HVDC transmission system simulation model sent outside with large-scale wind power |
| CN113852101A (en) * | 2021-09-26 | 2021-12-28 | 广东电网有限责任公司 | Method and device for determining risk of causing subsynchronous torsional vibration of steam turbine generator unit |
| CN113852101B (en) * | 2021-09-26 | 2023-06-13 | 广东电网有限责任公司 | Determination method and device for triggering subsynchronous torsional vibration risk of steam turbine generator unit |
| CN114362210A (en) * | 2022-01-12 | 2022-04-15 | 全球能源互联网研究院有限公司 | Wind power plant oscillation risk assessment testing method, avoiding method and storage medium |
| CN114362210B (en) * | 2022-01-12 | 2023-11-21 | 全球能源互联网研究院有限公司 | Wind farm oscillation risk assessment test method, avoidance method and storage medium |
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