CN107294127A - A kind of adaptive HVDC emergency DC power support methods - Google Patents
A kind of adaptive HVDC emergency DC power support methods Download PDFInfo
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- CN107294127A CN107294127A CN201710691043.2A CN201710691043A CN107294127A CN 107294127 A CN107294127 A CN 107294127A CN 201710691043 A CN201710691043 A CN 201710691043A CN 107294127 A CN107294127 A CN 107294127A
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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
- 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]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Abstract
The present invention proposes a kind of adaptive emergency DC power support methods of HVDC estimated in real time based on imbalance power in alternating current-direct current interconnected electric power system region, to solve alternating current-direct current interconnected electric power system caused generator's power and angle oscillation problem in the case of failure or disturbance.The present invention is configured by setting up the extended state observer of imbalance power in region under system disturbance to observer parameter, realizes the real-time accurate estimation of imbalance power.Limiting factor is supported to direct-current emergency power to analyze, and then emergency DC power support amount is optimized, final power support capacity is formed, and then, ladder is supported based on power and is incremented by principle, the target that power is supported finally is realized.The present invention is compared to traditional definite value emergency DC power support method, due to being capable of the imbalance power of estimating system in real time, so that power support capacity is adjusted in real time, therefore, it is possible to realize dynamic optimal power support target.
Description
Technical field
The present invention relates to the technical field of D.C. high voltage transmission additional transient control, and in particular to a kind of adaptive HVDC
Emergency DC power support method.
Background technology
Transferring electricity from the west to the east, the on national network general layout of north and south supply mutually have been preliminarily formed.Interconnection makes power network locally hair to power network on a large scale
Raw disturbance, neighbouring broad area will be fed through to quickly.At present, it is to send a telegram here in recent years to carry out regional power grid interconnection with HVDC
The principal mode of development is netted, due to the quick regulation characteristic and overload capacity of direct current, so as to the additional control of carry out to direct current
System, suppresses grid disturbance, improves the security and stability of interconnected network.Domestic and international substantial amounts of experts and scholars are carried out for this aspect
It is widely studied.Emergency DC power support is to be directed to interconnected electric power system, due to failure or disturbance, larger power surplus or work(occurs
The emergent control measure of rate vacancy.By the fast lifting of direct current or drop function is returned, suppress the first pendulum of generator's power and angle and follow-up
The stabilization of pendulum.As can be seen that the lifting capacity and Hui Jiangliang of existing emergency DC power support, are mainly according to warp from existing research
Test to determine, circular is not provided, and when emergency DC power support, support amount is essentially all fixed
Value.And in real system, imbalance power is due to system itself adjustment effect, the factor, the injustice of power such as load responding effect
Weighing apparatus is real-time dynamic change.
The content of the invention
For the lifting capacity and Hui Jiangliang of existing emergency DC power support, mainly rule of thumb determine, do not provide
Circular；And when emergency DC power support, support amount is essentially all fixed value, it is impossible to completely adaptive
Realize the technical problem that dynamic optimal power is supported, the present invention provides a kind of adaptive HVDC emergency DC power support methods.
In order to solve the above-mentioned technical problem, the technical solution adopted in the present invention is as follows：
A kind of adaptive HVDC emergency DC power support methods, step is as follows：
S1, asks for the equivalent angular velocity omega in the system equivalent center of inertia in power system regionCOI, calculation formula is：
Wherein, MJTFor whole generator inertia time constant sums, M in power system regionJiFor i-th generator
Inertia time constant；And the relation of system inertia center angular frequency and system inertia centre frequency is ωCOI=2 π fCOI。
S2, sets up the relationship of center of inertia unit frequency change rate and power variation；
Wherein,For center of inertia unit frequency change rate；PmFor the mechanical output of equivalent unit；PeFor equivalent unit
Electromagnetic power；f0For systematic steady state frequency, size is 50Hz；Δ P is region internal power amount of unbalance.
S3, by step S2It is considered as the disturbance quantity of power system, is designated as w (t), then center of inertia unit frequency
The relationship of rate rate of change and power variation is expressed as：
Formula 4 represents that 0 input system, i.e. controlled quentity controlled variable u are 0.
S4, according to step S3, draws the equation of state of center of inertia unit frequency change rate and power variation；
Wherein, x1(t)=f,
S5, according to step S4 and extended state observer principle, obtains center of inertia unit frequency change rate and becomes with power
The extended state observer equation of change amount；
Wherein, f is power system frequency；z1For f estimate；For z1Derivative；z2For the expansion state of system, i.e.,Estimate；For z2Derivative；β1、β2For extended state observer parameter；E is system frequency estimate and reality
The difference of value；α is the parameter more than 0 less than or equal to 1；D is the parameter relevant with sampling step length；Fal (e, α/2, d) it is Non-smooth surface letter
Number, when | e |>δ, fal (e, α/2, d) it is equal to | e |αSign (e), when | e |≤δ, fal (e, α/2, d) it is equal to e/ δ1-α/2；
S6, according to step S5 and with reference to Active Disturbance Rejection Control principle, obtains the pseudo- controlled quentity controlled variable Δ P of extended state observerm0。
Wherein,For region internal power amount of unbalance Δ P real-time estimation；b0For control input coefficient.
As control input coefficient b0During equal to 1, then Δ Pm0Size is equal toClaim Δ Pm0It is because actual for pseudo- controlled quentity controlled variable
Carry out power support when, due to by power support limiting factor influenceed, power support capacity is not necessarily equal to Δ Pm0,
And should be with Δ Pm0With certain relation.
S7, according to step S6, obtains the straight-flow system actual control variable Δ P of extended state observerm；
ΔPm=k Δs Pm0, 0≤k≤1 (8)；
Wherein, k is that power supports coefficient, and k is relevant with emergency DC power support limiting factor, the emergency DC power support limit
Factor processed includes ability to transmit electricity AC system busbar voltage level and straight-flow system in itself.
Due to being supported many influences such as limiting factor by power network adjustment effect itself, part throttle characteristics and power,
ΔPmNeed not be equal to Δ Pm0, and k values are optimized according to emergency DC power support limiting factor.
S8, according to the horizontal restrictive condition of AC system busbar voltage, calculates k values.
Concretely comprise the following steps：S8.1, defines voltage-sensitive level of factor FVSF, for assessing AC system busbar voltage level
Limitation to power ascension amount；
Wherein, Δ U is ac bus Voltage Drop amount caused by unit dc power lifting capacity；UNFor AC system bus
Voltage rating.
S8.2, according to step S8.1, obtains working as power ascension k Δs Pm0When, voltage-sensitive level of factor is changed into：
S8.3, according to step S8.2, compares k Δs Pm0*FVSFValue whether in voltage allow fluctuation range in, when k Δs
Pm0*FVSFValue be in voltage allow fluctuation range in, then k values be 1；Conversely, then according to the maximum of admissible voltage fluctuation
Calculate k values now.
S9, limits according to the ability to transmit electricity of straight-flow system in itself, sets up actual control variable Δ PmConstraints, further
Secondary calculating k values.
The ability to transmit electricity limitation of straight-flow system, HVDC transmission system in itself generally has 1.1 times of long-term overload
1.5 times of short-time overload capacities of ability and 3s, in addition to overlond running, DC transmission system also has minimum power limitation, this be by
Straight-flow system has what minimum current limit factor was determined, when electric current is less than limit value, will cause DC current cutout phenomenon.
So the constraints set up is：
ΔPmin≤kΔPm0≤ΔPmax(11)；
Wherein, Δ PminFor the minimum power of DC transmission system, Δ PmaxFor the peak power of DC transmission system.
S10, the k values that step S8 is obtained take common factor with the obtained k values of step S9, obtain final k values, and then obtain direct current
System actual control variable Δ Pm。
S11, principle is incremented by according to step S10 and based on ladder, is supported the factor using many feed-in power and is handed over directly from many drop points
Flow and an optimal DC transmission system progress power support is chosen in transmission system.
When reality is supported in power, typically system power lifting just once will not be arrived into k Δs Pm0, so operation is to system
Impulse ratio it is larger, therefore power need to be stepped up, finally realize the target that power is supported.For many drop point AC-HVDC systems
System, in theory during failure, every DC transmission system can reach realization interconnection by lifting the quantity of power of oneself
The balance of ac and dc systemses power, but the additional control effect of different DC transmission systems has certain difference, therefore adopt
The factor, which is supported, with many feed-in power carries out power ascension to choose an optimal straight-flow system.
The calculation procedure that many feed-in power support the factor is as follows：
S11.1, calculates many feed-in interaction factor FMIIF,ji, calculation formula is：
Wherein, j, i are variable, Δ UiIt is female in its current conversion station change of current for a certain straight-flow system run under nominal power
One parallel reactive power leg of switching, causes the variable quantity of the change of current busbar voltage on line；ΔUjIt is expressed as to be seen straight
Flow the voltage variety of current conversion station bus.
S11.2, calculates many effective short-circuit ratio K of feed-inMESCRi, calculation formula is：
Wherein, SaciFor three-phase shortcircuit capacity at current conversion station i change of current bus；QCNiTo be filtered at current conversion station i ac bus
The reactive power that ripple device and shunt capacitor are provided；PdNiFor straight-flow system i rated capacity, PdNjFor the specified of straight-flow system j
Capacity.
S11.3, according to step S11.1 and step S11.2, calculates many feed-in power and supports factor lambdaj,i, calculation formula is：
λj,i=FADIF,ji×KMESCRi (14)。
S11.4, obtains the peak power support factor from step S11.3, then peak power supports the corresponding direct current of the factor
Transmission system is optimal DC transmission system.
The present invention is joined by setting up the extended state observer of imbalance power in region under system disturbance to observer
Number is configured, and realizes the real-time accurate estimation of imbalance power.Limiting factor is supported to direct-current emergency power to analyze, and is entered
And emergency DC power support amount is optimized, final power support capacity is formed, then, supporting ladder based on power is incremented by principle,
It is final to realize the target that power is supported.For many drop point DC transmission systems, predictor selection is supported based on power and carried for power
The optimal direct current risen.Three infeed HVDC Systems are built in PSCAD, simulation analysis have been carried out to institute's extracting method, as a result table
Understand the validity of this method.Improving transient stability to alternating current-direct current interconnected electric power system emergency DC power support has stronger ginseng
Examine value.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the accompanying drawing used required in technology description to be briefly described, it should be apparent that, drawings in the following description are only this
Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, can be with
Other accompanying drawings are obtained according to these accompanying drawings.
Fig. 1 is extended state observer structure chart of the invention.
Fig. 2 is emergency DC power support additional controller structure chart of the present invention.
Fig. 3 is that emergency DC power support ladder of the present invention is incremented by schematic diagram.
Fig. 4 is the DC transmission system structure chart of three machine three.
System state amount-power system frequency value of observer estimation when Fig. 5 is systematic steady state.
System output quantity-Power System Disturbances value of observer estimation when Fig. 6 is systematic steady state.
When Fig. 7 whether there is emergency DC power support when being system disturbance, the change of system amount of unbalance.
When Fig. 8 whether there is emergency DC power support when being system disturbance, generator's power and angle change curve.
When Fig. 9 whether there is emergency DC power support when being system disturbance, HVDC3 power response figures.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is based on
Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not paid
Embodiment, belongs to the scope of protection of the invention.
In power system transient stability problem under studying failure, system is usually equivalent to two-shipper Failure Model.I.e.
System is divided into Critical Group S and remaining group A, therefore system angle stability sex chromosome mosaicism is the phase for being changed into Critical Group S to remaining group A
To flapping issue.Critical Group S and remaining group A transient motion equation is：
Wherein
In formula,MAFor Critical Group S and remaining group A equivalent inertia time constant；Respectively S's and A is used
Generator rotor angle under property center；Angular frequency under the respectively S and A center of inertia；I-th in respectively S
The mechanical output and electromagnetic power of unit；ForIn the equivalent mechanical output of jth platform unit and electromagnetic power.
Critical Group S and remaining group A transient motion equation are merged, then two group of planes transient motion state equations can be with equivalent
For one-of-a-kind system, equivalent one-of-a-kind system equation of rotor motion is
In formula, δSA=δS-δA, ωSA=ωS-ωA.For above-mentioned equivalent one-of-a-kind system, when normal table is run, thenFor 0.When internal system breaks down, then due to the effect of generator amature inertia, it is impossible to instantaneously ensure mechanical output
It is equal with electromagnetic power, then due to being added in the effect of unbalanced moments on generator amature, rotor acceleration or deceleration will be caused, this
WhenIt is not 0, if can not timely and effectively apply control measure, δ can be causedSAIncrease, beyond the operating point model that system is stable
Enclose, ultimately result in system unstability.
By cut caused by Critical Group S internal generator sudden catastrophic failures machine or power very big load in traffic control in terms of
Draw exemplified by outer unexpected startup, such case will cause the instantaneous vacancy of Critical Group S area powers, then the machine in Critical Group S
Group is less than electromagnetic power due to mechanical output, then rotor will slow down.If power is supported and is equivalent to mechanical output, equivalent
One-of-a-kind system by additional emergency power support measure, then be changed into
In formula, Δ PmAs direct-current emergency power support capacity.As can be seen from the above equation, the additional emergency power of direct current is passed through
Support measure, it is possible to achieve reduction rotor frequency is poor, so as to realize the purpose of stable generator rotor angle.
Based on above-mentioned theory, the present invention provides a kind of adaptive HVDC emergency DC power support methods, as Figure 1-3,
Step is as follows：
S1, asks for the equivalent angular velocity omega in the system equivalent center of inertia in power system regionCOI, calculation formula is：
Wherein, MJTFor whole generator inertia time constant sums, M in power system regionJiFor i-th generator
Inertia time constant；And the relation of system inertia center angular frequency and system inertia centre frequency is ωCOI=2 π fCOI。
S2, sets up the relationship of center of inertia unit frequency change rate and power variation；
Wherein,For center of inertia unit frequency change rate；PmFor the mechanical output of equivalent unit；PeFor equivalent unit
Electromagnetic power；f0For systematic steady state frequency, size is 50Hz；Δ P is region internal power amount of unbalance.
S3, by step S2It is considered as the disturbance quantity of power system, is designated as w (t), then center of inertia unit frequency
The relationship of rate rate of change and power variation is expressed as：
Formula 4 represents that 0 input system, i.e. controlled quentity controlled variable u are 0.
S4, according to step S3, draws the equation of state of center of inertia unit frequency change rate and power variation；
Wherein, x1(t)=f,
S5, according to step S4 and extended state observer principle, obtains center of inertia unit frequency change rate and becomes with power
The extended state observer equation of change amount；
Wherein, f is power system frequency；z1For f estimate；For z1Derivative；z2For the expansion state of system, i.e.,Estimate；For z2Derivative；β1、β2For extended state observer parameter；E is system frequency estimate and reality
The difference of value；α is the parameter more than 0 less than or equal to 1；D is the parameter relevant with sampling step length；Fal (e, α/2, d) it is Non-smooth surface letter
Number, when | e |>δ, fal (e, α/2, d) it is equal to | e |αSign (e), when | e |≤δ, fal (e, α/2, d) it is equal to e/ δ1-α/2；
S6, according to step S5 and with reference to Active Disturbance Rejection Control principle, obtains the pseudo- controlled quentity controlled variable Δ P of extended state observerm0。
Wherein,For region internal power amount of unbalance Δ P real-time estimation；b0For control input coefficient.
As control input coefficient b0During equal to 1, then Δ Pm0Size is equal toClaim Δ Pm0It is because actual for pseudo- controlled quentity controlled variable
Carry out power support when, due to by power support limiting factor influenceed, power support capacity is not necessarily equal to Δ Pm0,
And should be with Δ Pm0With certain relation.
S7, according to step S6, obtains the straight-flow system actual control variable Δ P of extended state observerm；
ΔPm=k Δs Pm0, 0≤k≤1 (8)；
Wherein, k is emergency DC power support coefficient, and k is relevant with emergency DC power support limiting factor, the urgent power branch
Help the ability to transmit electricity that limiting factor includes AC system busbar voltage level and straight-flow system in itself.
Due to being supported many influences such as limiting factor by power network adjustment effect itself, part throttle characteristics and power,
ΔPmNeed not be equal to Δ Pm0, and k values are optimized according to emergency DC power support limiting factor.
S8, according to the horizontal restrictive condition of AC system busbar voltage, calculates k values.
Concretely comprise the following steps：S8.1, defines voltage-sensitive level of factor FVSF, for assessing AC system busbar voltage level
Limitation to power ascension amount；
Wherein, Δ U is ac bus Voltage Drop amount caused by unit dc power lifting capacity；UNFor AC system bus
Voltage rating.
S8.2, according to step S8.1, obtains working as power ascension k Δs Pm0When, voltage-sensitive level of factor is changed into：
S8.3, according to step S8.2, compares k Δs Pm0*FVSFValue whether in voltage allow fluctuation range in, when k Δs
Pm0*FVSFValue be in voltage allow fluctuation range in, then k values be 1；Conversely, then according to the maximum of admissible voltage fluctuation
Calculate k values now.
S9, limits according to the ability to transmit electricity of straight-flow system in itself, sets up actual control variable Δ PmConstraints, further
Secondary calculating k values.
The ability to transmit electricity limitation of straight-flow system, HVDC transmission system in itself generally has 1.1 times of long-term overload
1.5 times of short-time overload capacities of ability and 3s, in addition to overlond running, DC transmission system also has minimum power limitation, this be by
Straight-flow system has what minimum current limit factor was determined, when electric current is less than limit value, will cause DC current cutout phenomenon.
So the constraints set up is：
ΔPmin≤kΔPm0≤ΔPmax(11)；
Wherein, Δ PminFor the minimum power of DC transmission system, Δ PmaxFor the peak power of DC transmission system.
S10, the k values that step S8 is obtained take common factor with the obtained k values of step S9, obtain final k values, and then obtain direct current
System actual control variable Δ Pm。
S11, principle is incremented by according to step S10 and based on ladder, is supported the factor using many feed-in power and is handed over directly from many drop points
Flow and an optimal DC transmission system progress power support is chosen in transmission system.
When reality is supported in power, typically system power lifting just once will not be arrived into k Δs Pm0, so operation is to system
Impulse ratio it is larger, therefore power need to be stepped up, finally realize the target that power is supported.For many drop point AC-HVDC systems
System, in theory during failure, every DC transmission system can reach realization interconnection by lifting the quantity of power of oneself
The balance of ac and dc systemses power, but the additional control effect of different DC transmission systems has certain difference, therefore adopt
The factor, which is supported, with many feed-in power carries out power ascension to choose an optimal straight-flow system.
The calculation procedure that many feed-in power support the factor is as follows：
S11.1, calculates many feed-in interaction factor FMIIF,ji, calculation formula is：
Wherein, j, i are variable, Δ UiIt is female in its current conversion station change of current for a certain straight-flow system run under nominal power
One parallel reactive power leg of switching, causes the variable quantity of the change of current busbar voltage on line；ΔUjIt is expressed as to be seen straight
Flow the voltage variety of current conversion station bus.
S11.2, calculates many effective short-circuit ratio K of feed-inMESCRi, calculation formula is：
Wherein, SaciFor three-phase shortcircuit capacity at current conversion station i change of current bus；QCNiTo be filtered at current conversion station i ac bus
The reactive power that ripple device and shunt capacitor are provided；PdNiFor straight-flow system i rated capacity, PdNjFor the specified of straight-flow system j
Capacity.
S11.3, according to step S11.1 and step S11.2, calculates many feed-in power and supports factor lambdaj,i, calculation formula is：
λj,i=FADIF,ji×KMESCRi (14)。
S11.4, obtains the peak power support factor from step S11.3, then peak power supports the corresponding direct current of the factor
Transmission system is optimal DC transmission system.
In order to verify effectiveness of the invention and robustness, the machine transmission system of three direct current three, topology knot are built in PSCAD
Structure is as shown in Figure 4.In the system, three DC lines use the CIGRE models of standard, and straight-flow system control mode is, whole
Stream side constant DC current control, inverter side determine hold-off angle control.Every time power of DC line is Pdc=1000MW, Vdc=
500kV.Generator model is using detailed six ranks model and all includes excitation and governing system, and all without power system stability
Device.Generator rated capacity G1And G3Equal is 700MVA, G2For 512MVA, three generator inertia time constants are H=
6.5s。
First, the parameter to Second Order Eso is adjusted, by parameter tuning separation property principle, with reference to warp
Parameter is tested, last Second Order Eso parameter tuning is that α/2 are that 0.5, d is 0.05, β1For 20, β2For 50.
During systematic steady state, Second Order Eso performance is tested, test result is as shown in Figure 5, Figure 6.From
As can be seen that by suitable parameter tuning, Second Order Eso can be realized to system state amount f on simulation result
Quick and precisely track, and system output is 0 during stable state, it was demonstrated that and the Second Order Eso is designed and parameter tuning is to close
Reason.
Feeder line branch road causes to lose load 652WM due to failure removal at disturbance emulation BUS2.Simulation result such as Fig. 7-9
It is shown.Fig. 7 is the system dynamic unbalance power that estimates of extended state observer, in Fig. 7 it can be seen from system injustice
Weighing apparatus power is the amount of dynamic change, a rather than steady state value.Dotted line is system when not putting into em ergency power support control device
Imbalance power, solid-line curve is the imbalance power for putting into em ergency power support control device.By contrast it can be found that input is tight
After anxious power controller, the purpose of system power balance can be realized with quick and stable.Fig. 8 be system in generator G1, G2 and
G3 power-angle curve, by contrasting same it can be found that putting into after urgent power controller, can effectively suppress generator's power and angle
Wave, generator rotor angle is relatively smooth transitioned into stable state.Fig. 9 is HVDC3 power response curves, puts into emergency DC power support
Afterwards, by the fast lifting and time drop function of dc power, the balance for maintaining system power can quickly be realized.
The present invention is joined by setting up the extended state observer of imbalance power in region under system disturbance to observer
Number is configured, and realizes the real-time accurate estimation of imbalance power.Limiting factor is supported to direct-current emergency power to analyze, and is entered
And emergency DC power support amount is optimized, final power support capacity is formed, then, supporting ladder based on power is incremented by principle,
It is final to realize the target that power is supported.For many drop point DC transmission systems, predictor selection is supported based on power and carried for power
The optimal direct current risen.Three infeed HVDC Systems are built in PSCAD, simulation analysis have been carried out to institute's extracting method, as a result table
Understand the validity of this method.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention
God is with principle, and any modification, equivalent substitution and improvements made etc. should be included in the scope of the protection.
Claims (3)
1. a kind of adaptive HVDC emergency DC power support methods, it is characterised in that step is as follows：
S1, asks for the equivalent angular velocity omega in the system equivalent center of inertia in power system regionCOI, calculation formula is：
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Wherein, MJTFor whole generator inertia time constant sums, M in power system regionJiFor the inertial time of i-th generator
Between constant；
S2, sets up the relationship of center of inertia unit frequency change rate and power variation；
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</mrow>
</msub>
</mfrac>
<mrow>
<mo>(</mo>
<msub>
<mi>P</mi>
<mi>m</mi>
</msub>
<mo>-</mo>
<msub>
<mi>P</mi>
<mi>e</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<msub>
<mi>f</mi>
<mn>0</mn>
</msub>
<msub>
<mi>M</mi>
<mrow>
<mi>J</mi>
<mi>T</mi>
</mrow>
</msub>
</mfrac>
<mi>&Delta;</mi>
<mi>P</mi>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>3</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein,For center of inertia unit frequency change rate；PmFor the mechanical output of equivalent unit；PeFor the electromagnetism of equivalent unit
Power；f0For systematic steady state frequency, size is 50Hz；Δ P is region internal power amount of unbalance；
S3, by step S2It is considered as the disturbance quantity of power system, is designated as w (t), then machine class frequency in the center of inertia becomes
Rate and the relationship of power variation are expressed as：
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<mover>
<mi>f</mi>
<mo>&CenterDot;</mo>
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<mo>=</mo>
<mi>w</mi>
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<mo>(</mo>
<mn>4</mn>
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</mrow>
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</mrow>
S4, according to step S3, draws the equation of state of center of inertia unit frequency change rate and power variation；
<mrow>
<mfenced open = "{" close = "">
<mtable>
<mtr>
<mtd>
<mrow>
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<mi>x</mi>
<mo>&CenterDot;</mo>
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<mi>x</mi>
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<mi>t</mi>
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</mrow>
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<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>5</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein, x1(t)=f,
S5, according to step S4, obtains the extended state observer equation of center of inertia unit frequency change rate and power variation
Formula；
<mrow>
<mfenced open = "{" close = "">
<mtable>
<mtr>
<mtd>
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<mi>e</mi>
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<mn>1</mn>
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<msub>
<mover>
<mi>z</mi>
<mo>&CenterDot;</mo>
</mover>
<mn>1</mn>
</msub>
<mo>=</mo>
<msub>
<mi>z</mi>
<mn>2</mn>
</msub>
<mo>-</mo>
<msub>
<mi>&beta;</mi>
<mn>1</mn>
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<mi>e</mi>
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<mi>z</mi>
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<mi>&beta;</mi>
<mn>2</mn>
</msub>
<mi>f</mi>
<mi>a</mi>
<mi>l</mi>
<mrow>
<mo>(</mo>
<mi>e</mi>
<mo>,</mo>
<mi>&alpha;</mi>
<mo>/</mo>
<mn>2</mn>
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<mi>d</mi>
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</mrow>
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<mo>-</mo>
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<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>6</mn>
<mo>)</mo>
</mrow>
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</mrow>
Wherein, f is power system frequency；z1For f estimate；For z1Derivative；z2For the expansion state of system, i.e.,Estimate；For z2Derivative；β1、β2For extended state observer parameter；E is system frequency estimate and reality
The difference of value；α is the parameter more than 0 less than or equal to 1；D is the parameter relevant with sampling step length；Fal (e, α/2, d) it is Non-smooth surface letter
Number, when | e |>δ, fal (e, α/2, d) it is equal to | e |αSign (e), when | e |≤δ, fal (e, α/2, d) it is equal to e/ δ1-α/2；
S6, according to step S5 and with reference to Active Disturbance Rejection Control principle, obtains the pseudo- controlled quentity controlled variable Δ P of extended state observerm0；
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<mi>&Delta;P</mi>
<mrow>
<mi>m</mi>
<mn>0</mn>
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<mo>-</mo>
<mi>&Delta;</mi>
<mover>
<mi>P</mi>
<mo>^</mo>
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<mi>b</mi>
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<mi>M</mi>
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<mi>J</mi>
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<msub>
<mi>f</mi>
<mn>0</mn>
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<mo>&times;</mo>
<msub>
<mi>b</mi>
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<mo>-</mo>
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1
Wherein,For region internal power amount of unbalance Δ P real-time estimation；b0For control input coefficient；
S7, according to step S6, obtains the straight-flow system actual control variable Δ P of extended state observerm；
ΔPm=k Δs Pm0, 0≤k≤1 (8)；
Wherein, k is emergency DC power support coefficient, and k is relevant with emergency DC power support limiting factor, the emergency DC power support limit
Factor processed includes ability to transmit electricity AC system busbar voltage level and straight-flow system in itself；
S8, according to the horizontal restrictive condition of AC system busbar voltage, calculates k values；
S9, limits according to the ability to transmit electricity of straight-flow system in itself, sets up actual control variable Δ PmConstraints, count again
Calculate k values；Constraints is：
ΔPmin≤kΔPm0≤ΔPmax(11)；
Wherein, Δ PminFor the minimum power of DC transmission system, Δ PmaxFor the peak power of DC transmission system；
S10, the k values that step S8 is obtained take common factor with the obtained k values of step S9, obtain final k values, and then obtain straight-flow system
Actual control variable Δ Pm；
S11, principle is incremented by according to step S10 and based on ladder, and it is defeated from many drop point alternating current-direct currents to support the factor using many feed-in power
An optimal DC transmission system is chosen in electric system and carries out power support.
2. adaptive HVDC emergency DC power support methods according to claim 1, it is characterised in that in step s 8,
Calculate concretely comprising the following steps for k values：
S8.1, defines voltage-sensitive level of factor FVSF, for assessing limit of the AC system busbar voltage level to power ascension amount
System；
<mrow>
<msub>
<mi>F</mi>
<mrow>
<mi>V</mi>
<mi>S</mi>
<mi>F</mi>
</mrow>
</msub>
<mo>=</mo>
<mfrac>
<mrow>
<mi>&Delta;</mi>
<mi>U</mi>
</mrow>
<msub>
<mi>U</mi>
<mi>N</mi>
</msub>
</mfrac>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>9</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein, Δ U is ac bus Voltage Drop amount caused by unit dc power lifting capacity；UNFor AC system busbar voltage
Rated value；
S8.2, according to step S8.1, obtains working as power ascension k Δs Pm0When, voltage-sensitive level of factor is changed into：
<mrow>
<msub>
<mi>k&Delta;P</mi>
<mrow>
<mi>m</mi>
<mn>0</mn>
</mrow>
</msub>
<mo>*</mo>
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<mi>F</mi>
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<mi>F</mi>
</mrow>
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<mi>k&Delta;P</mi>
<mrow>
<mi>m</mi>
<mn>0</mn>
</mrow>
</msub>
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<mi>&Delta;</mi>
<mi>U</mi>
</mrow>
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<mi>U</mi>
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<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>10</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
S8.3, according to step S8.2, compares k Δs Pm0*FVSFValue whether in voltage allow fluctuation range in, as k Δs Pm0*
FVSFValue be in voltage allow fluctuation range in, then k values be 1；Conversely, then according to the maximum meter of admissible voltage fluctuation
Calculate k values now.
3. adaptive HVDC emergency DC power support methods according to claim 1, it is characterised in that in step s 11,
The calculation procedure that many feed-in power support the factor is as follows：
S11.1, calculates many feed-in interaction factor FMIIF,ji, calculation formula is：
<mrow>
<msub>
<mi>F</mi>
<mrow>
<mi>M</mi>
<mi>I</mi>
<mi>I</mi>
<mi>F</mi>
<mo>,</mo>
<mi>j</mi>
<mi>i</mi>
</mrow>
</msub>
<mo>=</mo>
<mfrac>
<mrow>
<msub>
<mi>&Delta;U</mi>
<mi>j</mi>
</msub>
</mrow>
<mrow>
<msub>
<mi>&Delta;U</mi>
<mi>i</mi>
</msub>
</mrow>
</mfrac>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>12</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein, j, i are variable, Δ UiFor a certain straight-flow system run under nominal power, in its current conversion station change of current bus upslide
A parallel reactive power leg is cut, the variable quantity of the change of current busbar voltage is caused；ΔUjIt is expressed as DC converter to be seen
Stand the voltage variety of bus；
S11.2, calculates many effective short-circuit ratio K of feed-inMESCRi, calculation formula is：
<mrow>
<msub>
<mi>K</mi>
<mrow>
<mi>M</mi>
<mi>E</mi>
<mi>S</mi>
<mi>C</mi>
<mi>R</mi>
<mi>i</mi>
</mrow>
</msub>
<mo>=</mo>
<mfrac>
<mrow>
<msub>
<mi>S</mi>
<mrow>
<mi>a</mi>
<mi>c</mi>
<mi>i</mi>
</mrow>
</msub>
<mo>-</mo>
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<mi>Q</mi>
<mrow>
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<mi>i</mi>
</mrow>
</msub>
</mrow>
<mrow>
<msub>
<mi>P</mi>
<mrow>
<mi>d</mi>
<mi>N</mi>
<mi>i</mi>
</mrow>
</msub>
<mo>+</mo>
<munder>
<mo>&Sigma;</mo>
<mrow>
<mi>j</mi>
<mo>,</mo>
<mi>j</mi>
<mo>&NotEqual;</mo>
<mi>i</mi>
</mrow>
</munder>
<mrow>
<mo>(</mo>
<msub>
<mi>F</mi>
<mrow>
<mi>M</mi>
<mi>I</mi>
<mi>I</mi>
<mi>F</mi>
<mo>,</mo>
<mi>j</mi>
<mi>i</mi>
</mrow>
</msub>
<mo>&times;</mo>
<msub>
<mi>P</mi>
<mrow>
<mi>d</mi>
<mi>N</mi>
<mi>j</mi>
</mrow>
</msub>
<mo>)</mo>
</mrow>
</mrow>
</mfrac>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>13</mn>
<mo>)</mo>
</mrow>
<mo>;</mo>
</mrow>
Wherein, SaciFor three-phase shortcircuit capacity at current conversion station i change of current bus；QCNiFor wave filter at current conversion station i ac bus
The reactive power provided with shunt capacitor；PdNiFor straight-flow system i rated capacity, PdNjFor straight-flow system j rated capacity；
S11.3, according to step S11.1 and step S11.2, calculates many feed-in power and supports factor lambdaj,i, calculation formula is：
λj,i=FADIF,ji×KMESCRi(14)；
S11.4, obtains the peak power support factor from step S11.3, then peak power supports the corresponding direct current transportation of the factor
System is optimal DC transmission system.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108879729A (en) * | 2018-07-24 | 2018-11-23 | 山东大学 | Direct current interacted system frequency Emergency Assistance and quick recovery control method and system |
| CN110492494A (en) * | 2019-08-30 | 2019-11-22 | 郑州轻工业学院 | Voltage source converter direct Power Control method based on the interior theory of modules |
| CN112366705A (en) * | 2020-11-16 | 2021-02-12 | 深圳供电局有限公司 | Flexible direct current converter station and backup power automatic switching device time sequence coordination method and system |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110492499B (en) * | 2019-09-11 | 2020-07-31 | 郑州轻工业学院 | Coordinated optimization control method for multi-feed-in direct-current auxiliary power/frequency combined controller |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035214A (en) * | 2010-12-15 | 2011-04-27 | 山东大学 | System operating mode selecting method in process of restoring direct current support weak receiving system |
| CN105207235A (en) * | 2015-09-11 | 2015-12-30 | 国网浙江省电力公司 | Electric power system wide-area PID damping controller with large-range-change time-lag self-adaptive ability and design method thereof |
-
2017
- 2017-08-14 CN CN201710691043.2A patent/CN107294127B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035214A (en) * | 2010-12-15 | 2011-04-27 | 山东大学 | System operating mode selecting method in process of restoring direct current support weak receiving system |
| CN105207235A (en) * | 2015-09-11 | 2015-12-30 | 国网浙江省电力公司 | Electric power system wide-area PID damping controller with large-range-change time-lag self-adaptive ability and design method thereof |
Non-Patent Citations (2)
| Title |
|---|
| L.A.S. PILOTTO AND .ETC: "《HIGH FREQUENCY EICENANALYSIS OF HVDC AND FACTS ASSISTED POWER SYSTEMS》", 《2000 POWER ENGINEERING SOCIETY SUMMER MEETING》 * |
| 姜素霞，李春文，崔光照，金楠: "《高压直流输电系统中换流器的非线性控制及仿真研究》", 《电气应用》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108879729A (en) * | 2018-07-24 | 2018-11-23 | 山东大学 | Direct current interacted system frequency Emergency Assistance and quick recovery control method and system |
| CN110492494A (en) * | 2019-08-30 | 2019-11-22 | 郑州轻工业学院 | Voltage source converter direct Power Control method based on the interior theory of modules |
| CN110492494B (en) * | 2019-08-30 | 2021-09-24 | 郑州轻工业学院 | Direct power control method of voltage source converter based on internal model theory |
| CN112366705A (en) * | 2020-11-16 | 2021-02-12 | 深圳供电局有限公司 | Flexible direct current converter station and backup power automatic switching device time sequence coordination method and system |
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