CN105720585A - Reactive power control method and reactive power control system for wind farm clusters - Google Patents

Abstract

The invention discloses a reactive power control method and a reactive power control system for wind farm clusters. The method comprises the following steps: a wind farm cluster control device extracts the target grid-connection point voltage of each wind farm in a wind farm cluster from a voltage instruction issued by a dispatching center; the wind farm cluster control device detects a preset range to which the current grid-connection point voltage uploaded by each wind farm belongs; if the current grid-connection point voltage uploaded by any wind farm is within a normal operation range, the AVC substation of the wind farm enters a local control mode under control; if the current grid-connection point voltage uploaded by any wind farm is within an abnormal operation range, the AVC substation of the wind farm enters a coordinated control mode under control, a coordinated AVC substation is chosen from the wind farm cluster according to the sensitivity of reactive voltage and the reactive power adjustable capacity of each wind farm to assist in making the grid-connection point voltage of the wind farm in a coordinated control mode achieve the target voltage; and if the current grid-connection point voltage uploaded by any wind farm is within an emergency operation range, the AVC substation of the wind farm enters an emergency control mode under control, and the grid-connection point voltage of the wind farm is controlled through generator tripping, load shedding or wind farm cutting-off.

Description

The reactive power control method of wind power plant cluster and system

Technical field

The present invention relates to wind power plant cluster and control technical field, particularly relate to reactive power control method and the system of a kind of wind power plant cluster.

Background technology

At present, due to the impact by hierarchical balance local compensation viewpoint, the most research emphasis for wind energy turbine set has all concentrated on the reactive power and voltage control to single wind energy turbine set both at home and abroad, it is considered to the research of the cooperation between close wind energy turbine set is fewer.

China's wind energy turbine set often concentrates construction, forms large-scale wind power plant cluster, and multiple wind energy turbine set are concentrated and accessed same transformer station formation wind power plant cluster, difficulty is brought to traffic department, with regard to idle aspect, due to the undulatory property of wind-powered electricity generation, strong impact area voltage levvl.

In the area that wind energy turbine set is more, for this on geographical position contiguous, have identical characteristics and access the wind power plant cluster of same transformer station, using wind energy turbine set as elementary cell, the reactive power/voltage control pattern of local compensation is not optimum, wind single game carries out alone the mode of reactive voltage adjustment can not meet the requirement of electrical network, reactive power distribution in region can be made improper, and area global voltage level declines.

Summary of the invention

The invention provides the reactive power control method of a kind of wind power plant cluster and system, at least to solve the Reactive Power Control problem of wind power plant cluster.

According to an aspect of the present invention, provide the reactive power control method of a kind of wind power plant cluster, wind power plant cluster controls device and receives the voltage instruction that control centre issues, and from described voltage instruction, extract the grid-connected point voltage of target of each wind energy turbine set in wind power plant cluster, wherein, described wind power plant cluster control device is arranged on the transformer station that each wind energy turbine set described is collected；Described wind power plant cluster controls device and receives the current grid-connected point voltage that each wind energy turbine set described is uploaded, and described current grid-connected point voltage and pre-set interval is compared, and detects the interval at described current grid-connected point voltage place；If described current grid-connected point voltage is in properly functioning interval, described wind power plant cluster controls device and controls the AVC substation (automatism voltage control of this wind energy turbine set, AutomaticVoltageControl) local control model is entered, and issuing the grid-connected point voltage of described target to described AVC substation, the grid-connected point voltage being controlled described wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of described target；If described current grid-connected point voltage is in misoperation interval, described wind power plant cluster controls device and controls the AVC substation entrance coordination control model of this wind energy turbine set, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in described wind power plant cluster, control described coordination AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target；If described current grid-connected point voltage is in urgent traffic coverage, described wind power plant cluster controls device and controls the AVC substation entrance emergent control pattern of this wind energy turbine set, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

In one embodiment, described pre-set interval divides according to wind farm grid-connected point voltage, and properly functioning interval is $V_{i-\min }^I<V_i<V_{i-\max }^I,$ Misoperation interval is $V_{i-\min }^{\mathrm{II}}\&le;V_i\&le;V_{i-\min }^I$ Or $V_{i-\max }^I\&le;V_i\&le;V_{i-\max }^{\mathrm{II}},$ Urgent traffic coverage isOrWherein, i represents the numbering of wind energy turbine set, V_iRepresent wind farm grid-connected point voltage, $V_{i-\min }^{\mathrm{II}}<V_{i-\min }^I{<V}_{i-\max }^I<V_{i-\max }^{\mathrm{II}}.$

In one embodiment, in described wind power plant cluster, select to coordinate AVC substation according to the idle variable capacity of reactive voltage sensitivity and each wind energy turbine set to include: adopt below equation to calculate all wind energy turbine set reactive voltage sensitivity coefficient matrix S:S=-(B ") to being in the wind energy turbine set i coordinating control model in described wind power plant cluster^-1V^-1, wherein, the element S in reactive voltage sensitivity coefficient matrix S_ijThe sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes for wind energy turbine set i；B is " for the admittance matrix of circuit, matrix's reversibility in described wind power plant cluster；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；By the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small, and selected and sorted coordinates AVC substation in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as described.

In one embodiment, control described coordination AVC substation output reactive power, include to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target: the difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculate the idle adjustment amount that described coordination AVC substation needs to provide；The idle coordination control instruction carrying described idle adjustment amount is issued to described coordination AVC substation, described coordination AVC substation, according to described idle adjustment amount output reactive power, makes the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of described target；Wherein, described coordination AVC substation is according to after described idle adjustment amount output reactive power, and the described grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

In one embodiment, difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculating described AVC substation of coordinating needs the idle adjustment amount provided to include: adopt below equation to calculate the described idle adjustment amount Δ Q coordinating AVC substation_i: Δ V_j=S Δ Q_i, wherein, Δ V_jThe difference of current grid-connected point voltage with the grid-connected point voltage of described target for being in the wind energy turbine set j coordinating control model, idle adjustment amount Δ Q_iWithin the scope of the described variable capacity coordinating AVC substation.

In one embodiment, machine is cut in employing, the mode of removal of load or wind cutting field controls the grid-connected point voltage of this wind energy turbine set and includes: the AVC substation being in emergent control pattern issues Reactive-power control instruction to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, described wind power plant cluster controls device detection and reaches deliberate action delay time, the AVC substation then controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, described deliberate action delay time is more than the action cycle of the described AVC substation being in emergent control pattern, the described action cycle is that Reactive-power control sent instructions to the time of Wind turbines or reactive-load compensation equipment execution action from the described AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.

According to another aspect of the present invention, provide the power reactive power control system of a kind of wind power plant cluster, including: control centre, wind power plant cluster control device and wind power plant cluster, wherein, described wind power plant cluster includes the AVC substation of at least two wind energy turbine set and correspondence, and described wind power plant cluster controls device and is arranged on the transformer station that described at least two wind energy turbine set is collected；Described wind power plant cluster controls device and includes: acquisition module, detection module and control module；Described acquisition module, for receiving the voltage instruction that described control centre issues, and extracts the grid-connected point voltage of target of described at least two wind energy turbine set from described voltage instruction；Described detection module, for receiving the current grid-connected point voltage that described at least two wind energy turbine set is uploaded, and compares described current grid-connected point voltage and pre-set interval, detects the interval at described current grid-connected point voltage place；Described control module, for when described current grid-connected point voltage is in properly functioning interval, the AVC substation controlling this wind energy turbine set enters local control model, and issuing the grid-connected point voltage of described target to described AVC substation, the grid-connected point voltage being controlled described wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of described target；When described current grid-connected point voltage is in misoperation interval, the AVC substation controlling this wind energy turbine set enters coordination control model, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in described wind power plant cluster, control described coordination AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target；And when described current grid-connected point voltage is in urgent traffic coverage, the AVC substation controlling this wind energy turbine set enters emergent control pattern, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

In one embodiment, described control module includes: the first control unit, for adopting below equation to calculate all wind energy turbine set reactive voltage sensitivity coefficient matrix S:S=-(B ") to being in the wind energy turbine set i coordinating control model in described wind power plant cluster^-1V^-1, wherein, the element S in reactive voltage sensitivity coefficient matrix S_ijThe sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes for wind energy turbine set i；B is " for the admittance matrix of circuit, matrix's reversibility in described wind power plant cluster；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；By the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small；Selected and sorted coordinates AVC substation in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as described.

In one embodiment, described control module includes: the second control unit, for the difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculate the idle adjustment amount that described coordination AVC substation needs to provide；The idle coordination control instruction carrying described idle adjustment amount is issued to described coordination AVC substation, described coordination AVC substation, according to described idle adjustment amount output reactive power, makes the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of described target；Wherein, described coordination AVC substation is according to after described idle adjustment amount output reactive power, and the described grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

In one embodiment, described control module includes: the 3rd control unit, for issuing Reactive-power control instruction in the AVC substation being in emergent control pattern to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, detection reaches deliberate action delay time, the AVC substation controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, described deliberate action delay time is more than the action cycle of the described AVC substation being in emergent control pattern, the described action cycle is to issue the Reactive-power control instruction time to Wind turbines or reactive-load compensation equipment execution action from the described AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.

By the reactive power control method of the wind power plant cluster of the present invention and system, traffic coverage is preset for wind farm grid-connected point voltage, corresponding different control models, wind power plant cluster is set in the transformer station that each wind energy turbine set is collected and controls device, control centre is assisted jointly to complete the control to wind power plant cluster, coordinate to control that each wind energy turbine set is idle exerts oneself, reducing on the basis of reactive reserve, ensure that the voltage of each wind energy turbine set remains stable for, improve area voltage levvl, optimize the reactive power of large-scale wind power field group.Further, the mode cutting machine, removal of load or wind cutting field is adopted to carry out emergent control, it is to avoid to cause the serious consequences such as the extensive off-grid of wind power plant cluster, system unstability, area power grid collapse of voltage.

Accompanying drawing explanation

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, and the schematic description and description of the present invention is used for explaining the present invention, is not intended that limitation of the invention.In the accompanying drawings:

Fig. 1 is the flow chart of the reactive power control method of the wind power plant cluster of the embodiment of the present invention；

Fig. 2 is the structured flowchart of the power reactive power control system of the wind power plant cluster of the embodiment of the present invention.

Detailed description of the invention

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 clearly and completely described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on embodiments of the invention, the every other embodiment that those of ordinary skill in the art obtain under not making creative work premise, broadly fall into protection scope of the present invention.

Embodiments providing the reactive power control method of a kind of wind power plant cluster, Fig. 1 is the flow chart of the reactive power control method of the wind power plant cluster of the embodiment of the present invention.As it is shown in figure 1, the method comprises the following steps:

Step S101, wind power plant cluster controls device and receives the voltage instruction that control centre issues, and extracts the grid-connected point voltage of target of each wind energy turbine set in wind power plant cluster from voltage instruction.Wherein, wind power plant cluster controls device and is arranged on the transformer station that each wind energy turbine set is collected, and assists control centre jointly to complete the control to wind power plant cluster.In wind power plant cluster, the grid-connected point voltage of target of each wind energy turbine set is identical.

Step S102, wind power plant cluster controls device and receives the current grid-connected point voltage that each wind energy turbine set is uploaded, and current grid-connected point voltage and pre-set interval is compared, and detects the interval at current grid-connected point voltage place.To each wind energy turbine set, detect the pre-set interval at its current grid-connected point voltage place respectively, to determine the control model of correspondence.

Step S103, if current grid-connected point voltage is in properly functioning interval, wind power plant cluster controls device and controls the local control model of AVC substation entrance of this wind energy turbine set, and the grid-connected point voltage of target is issued to AVC substation, the grid-connected point voltage being controlled wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of target.Current grid-connected point voltage is in properly functioning interval, represents that wind energy turbine set can be exported by own reactive, makes grid-connected point voltage reach target voltage.

Step S104, if current grid-connected point voltage is in misoperation interval, wind power plant cluster controls device and controls the AVC substation entrance coordination control model of this wind energy turbine set, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in wind power plant cluster, control to coordinate AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of target.Current grid-connected point voltage is in misoperation interval, represents the idle deficiency of wind energy turbine set, grid-connected point voltage out-of-limit entrance misoperation district, is difficult to make grid-connected point voltage reach target voltage by own reactive output, it is necessary to the assistance of other measures.Select suitable wind energy turbine set to coordinate current grid-connected point voltage in wind power plant cluster and be in the wind energy turbine set that misoperation is interval, carry out reactive power output so that it is target voltage can be reached.

Step S105, if current grid-connected point voltage is in urgent traffic coverage, wind power plant cluster controls device and controls the AVC substation entrance emergent control pattern of this wind energy turbine set, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

Reactive power control method by the wind power plant cluster of the embodiment of the present invention, traffic coverage is preset for wind farm grid-connected point voltage, corresponding different control models, wind power plant cluster is set in the transformer station that each wind energy turbine set is collected and controls device, control centre is assisted jointly to complete the control to wind power plant cluster, coordinate to control that each wind energy turbine set is idle exerts oneself, reducing on the basis of reactive reserve, ensure that the voltage of each wind energy turbine set remains stable for, improve area voltage levvl, optimize the reactive power of large-scale wind power field group.Further, the mode cutting machine, removal of load or wind cutting field is adopted to carry out emergent control, it is to avoid to cause the serious consequences such as the extensive off-grid of wind power plant cluster, system unstability, area power grid collapse of voltage.

Above-mentioned pre-set interval divides according to wind farm grid-connected point voltage, and properly functioning interval is $V_{i-\min }^I<V_i<V_{i-\max }^I,$ Misoperation interval is $V_{i-\min }^{\mathrm{II}}\&le;V_i\&le;V_{i-\min }^I$ Or $V_{i-\max }^I\&le;V_i\&le;V_{i-\max }^{\mathrm{II}},$ Urgent traffic coverage isOrWherein, i represents the numbering of wind energy turbine set, and Vi represents wind farm grid-connected point voltage,Demarcation interval, it is possible to make full use of the voltage regulation capability of each wind energy turbine set substation self in cluster, contributes to according to different modes the output reactive power of wind energy turbine set and grid-connected point voltage being control effectively, and improves efficiency.

Wind farm grid-connected point voltage is distinctly claimed by " State Grid Corporation of China wind energy turbine set access electric power network technique regulation ", it is stipulated that in require that grid-connected point voltage can only fluctuate in-the 3% of rated voltage～7% scope.Therefore, it can arrangeP.u. it is perunit value, represents the multiple of rated voltage.According to power system inverse regulation voltage thought, in order to ensure that wind farm grid-connected point voltage is stable, when output of wind electric field is bigger, its voltage is setWhen output of wind electric field is less, its voltage is set

The interval residing for current grid-connected point voltage according to wind energy turbine set, it is possible to the control of wind energy turbine set AVC substation is divided into following three kinds of control models:

(1) local control model: now wind farm grid-connected point voltage is in properly functioning interval, wind energy turbine set AVC substation performs wind power plant cluster and controls the voltage instruction that device issues.

(2) control model is coordinated: now wind farm grid-connected point voltage is in misoperation interval, wind energy turbine set AVC substation performs wind power plant cluster and controls the idle adjustment instruction that device issues, reactive power support is provided, until all wind energy turbine set substations are in local control model for wind power plant cluster regional power grid.Take into account the coordination of reactive power between wind energy turbine set.

(3) emergent control pattern: now wind farm grid-connected point voltage is in urgent traffic coverage, namely the voltage of wind energy turbine set controls through this locality and coordinates to control still to can not get there is efficient recovery (reactive power compensation planning is used up), worsen further and enter urgent traffic coverage, now wind energy turbine set should be carried out emergent control.

Under normal circumstances, each AVC substation in wind power plant cluster region operates in local control model, relies on AVC substation to automatically control grid-connected point voltage near target voltage values.When the substation i that Reactive-power control ability in cluster is more weak cannot meet local reactive requirement, voltage that voltage collects transformer station at desired value and wind farm grid-connected point voltage or cluster changes beyond the properly functioning interval of voltage to rely on our station to control to maintain, voltage out-of-limit enters during misoperation interval (this AVC substation can be described as out-of-limit substation), out-of-limit substation sends warning message and controls device to wind power plant cluster, and enters coordination control model.Wind power plant cluster controls device and issues idle coordination control instruction to the relevant substation participating in coordinating to control, and utilizes reactive power compensation planning more than needed in cluster regions to provide reactive power support for wind energy turbine set i, makes the grid-connected point voltage of wind energy turbine set i recover normal level.

Under local control model, wind energy turbine set AVC substation receives wind power plant cluster and controls the grid-connected point voltage desired value that device issues, and monitor the current grid-connected point voltage (i.e. actual value) of wind energy turbine set in real time, obtain the difference of desired value and actual value, wind energy turbine set is optimized by the optimisation strategy adopting substation, ensureing on the basis that wind farm grid-connected point voltage follows the tracks of target voltage, wind energy turbine set builtin voltage is made to obtain optimum.

When in cluster regions certain wind energy turbine set idle not enough time, during the out-of-limit entrance misoperation interval of wind farm grid-connected point voltage, this wind energy turbine set substation enters coordinates control model.The variable capacity of the reactive apparatus in field is uploaded to wind power plant cluster and controls device by wind energy turbine set, wind power plant cluster controls the substation that device selects to participate in coordinating to control according to the idle variable capacity of reactive voltage sensitivity and each wind energy turbine set, calculated the idle adjustment amount coordinating substation by the voltage deviation value of out-of-limit substation, then issue idle adjustment amount to coordinating substation.

Coordinating choosing for large-scale wind power field cluster of substation, control target makes the voltage collecting transformer station meet on the basis of scheduling requirement, and region interior nodes voltage meets requirement and also optimized.Due to the randomness of wind energy, the wind energy turbine set in the cluster of large-scale wind power field is meritorious exerts oneself and can be continually changing, and so can cause that each wind farm grid-connected point voltage ceaselessly fluctuates.When carrying out Load flow calculation, for the high-tension line of large-scale wind power field cluster, its reactance value, often much larger than its resistance value, can obtain according to PQ decomposition method:

Δ Q=-VB " Δ V (1)

In formula (1), Δ Q is the reactive power changing value of wind farm grid-connected output；" for the admittance matrix of circuit in the cluster of large-scale wind power field, matrix's reversibility, matrix belongs to sparse type matrix to B；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；Δ V is each node voltage variable quantity of region.Can be obtained by formula (1):

Δ V=-(B ")^-1V^-1ΔQ(2)

Then in wind power plant cluster, the reactive voltage sensitivity coefficient matrix S (being alternatively referred to as voltage to idle sensitivity coefficient matrix S) being in the wind energy turbine set coordinating control model is by all wind energy turbine set:

S=-(B ")^-1V^-1(3)

Element S in reactive voltage sensitivity coefficient matrix S in formula (3)_ijFor the sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes (being alternatively referred to as the i-th point voltage change sensitivity coefficient to the jth idle change of point) of wind energy turbine set i, its size is relevant with electrical network each node voltage value and network architecture parameters；S_iiFor our station voltage, our station is adjusted idle sensitivity.

The selection gist coordinating substation is wind energy turbine set substation size of numerical value in sensitivity coefficient matrix, the preferential substation selecting sensitivity big.Concrete, it is possible to by the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small, and selected and sorted in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as coordinate AVC substation.For preventing certain wind energy turbine set from the situation that Reactive-power control ability is used up occur, the coordination substation being selected all should participate in coordinating control as far as possible.According to practical situation, one or more coordination substation can be selected, choose the big conduct of sensitivity and coordinate substation, it is possible to quickly respond, be in the idle of the substation of coordinating control model to adjust so that it is reach the grid-connected point voltage of target.If the idle variable capacity of the substation that sensitivity is maximum is not enough, under the premise leaving certain nargin for it, the substation of sensitivity second or less is used to also serve as coordination substation.

In one embodiment, step S104 controls coordinate AVC substation output reactive power, may include that the difference according to the current grid-connected point voltage with the grid-connected point voltage of target being in the wind energy turbine set coordinating control model to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of target, calculate and coordinate the idle adjustment amount that AVC substation needs to provide；Issue, to coordinating AVC substation, the idle coordination control instruction carrying idle adjustment amount, coordinate AVC substation according to idle adjustment amount output reactive power, make the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of target；Wherein, coordinating AVC substation according to after idle adjustment amount output reactive power, the grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

Preferably, it is possible to adopt below equation to calculate the idle adjustment amount Δ Q coordinating AVC substation i_i:

ΔV_j=S Δ Q_i(4)

In formula (4), Δ V_jThe difference (i.e. the voltage deviation amount of out-of-limit substation) of current grid-connected point voltage with the grid-connected point voltage of target for being in the wind energy turbine set j coordinating control model；Being handed down to the idle adjustment amount coordinating AVC substation i should within the scope of the variable capacity coordinating AVC substation i.

Constraints is as follows:

1) wind power plant cluster controls the idle adjustment amount Δ Q that device issues to substation_iShould at the variable capacity scope Q of substation_avaIn:

0<ΔQ_i<Q_ava(5)

2) substation adjust idle after, substation voltage V_i ^newShould be maintained in permission range of operation:

$V_i^{\mathrm{new}}=V_i^{\mathrm{old}}+{\mathrm{\&Delta;Q}}_i{S}_{\mathrm{ii}}---\left(6\right)$

$V_{i-\min }^I<V_i^{\mathrm{new}}<V_{i-\max }^I---\left(7\right)$

In one embodiment, step S105 adopts and cuts machine, the mode of removal of load or wind cutting field controls the grid-connected point voltage of this wind energy turbine set and may include that the AVC substation being in emergent control pattern issues Reactive-power control instruction to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, wind power plant cluster controls device detection and reaches deliberate action delay time, the AVC substation then controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, deliberate action delay time is more than the action cycle of the AVC substation being in emergent control pattern, action cycle is the Reactive-power control instruction time to Wind turbines or reactive-load compensation equipment execution action that issues from the AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time (such as, 30 minutes) always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.

Arranging action delay is that the Reactive-power control ability making AVC system is fully used, and when reactive power capability is used up, just carries out the emergent control such as machine of cutting, wind cutting field.The action cycle of wind energy turbine set AVC substation is the time sent instructions from substation to blower fan or reactive-load compensation equipment action, the action cycle of AVC substation is general≤and 30 seconds.For example, it is possible to deliberate action delay time is set to 45 seconds.

Under extreme wind weather condition, meritorious the exerting oneself of wind power plant cluster may be significantly high even close to nominal output, and System Reactive Power loss substantially increases, and system voltage is degradation because of idle deficiency, far below rated voltage.In cluster regions during electrical network generation large disturbances, wind energy turbine set collects transformer station and regional power grid will dramatic drop-off or rising, if taking effective control measure not in time, it is possible to cause the serious consequences such as the extensive off-grid of wind farm group, system unstability, area power grid collapse of voltage.When operation of power networks is under minimum mode, wind farm grid-connected point, wind power plant cluster critical point and region voltage may be seriously higher, it could even be possible to exceed voltage to run the permission upper limit.

When wind farm grid-connected point, wind energy turbine set collect substation bus bar voltage beyond its normal control ability, it is necessary to carry out the emergent control of reactive voltage.When carrying out emergent control, it is considered as arranging action delay, makes the Reactive-power control ability of AVC substation be fully used, when reactive power capability is used up, just carry out the emergent control such as machine of cutting, removal of load, wind cutting field.The setting of action delay should be greater than the action cycle of wind energy turbine set AVC substation.The action delay of emergent control can be set as the Δ t=45 second.

The machine of cutting refers to part regulating power deficiency or distance transformer station Wind turbines farther out in excision wind power plant cluster.Removal of load, namely relies primarily on low-voltage load sheding device cut-away area grid parts load, preferentially excises inessential load in voltage minimum point.When having power load in regional power grid, cut-out Wind turbines or cut-out power load both modes can be adopted.Time in the electrical network of cluster regions without power load, can only take to cut machine mode and carry out emergent control.

When large-scale wind power field cluster wind-force is less, the meritorious possibility of exerting oneself of certain wind energy turbine set in region is only small, the charge power of such circuit may make wind farm grid-connected point voltage raise, it could even be possible to the scope being automatically adjusted beyond wind energy turbine set, when wind farm grid-connected point voltage is for a long time higher than the peak set, it is necessary to excise this wind energy turbine set.The voltage of the bus collecting transformer station when wind energy turbine set is higher thanTime, confirm, when Reactive-power control equipment is used up, to excise a certain wind energy turbine set and send circuit.

Based on same inventive concept, the embodiment of the present invention additionally provides the power reactive power control system of a kind of wind power plant cluster, it is possible to for realizing the method described by above-described embodiment, such as the following examples.Owing to the principle of the power reactive power control system solution problem of wind power plant cluster is similar to the reactive power control method of wind power plant cluster, therefore the enforcement of the power reactive power control system of wind power plant cluster may refer to the enforcement of the reactive power control method of wind power plant cluster, repeats part and repeats no more.

Fig. 2 is the structured flowchart of the power reactive power control system of the wind power plant cluster of the embodiment of the present invention, as shown in Figure 2, this system includes: control centre 10, wind power plant cluster control device 20 and wind power plant cluster 30, wind power plant cluster 30 includes the AVC substation 32 of at least two wind energy turbine set 31 and correspondence, and wind power plant cluster controls device 20 and is arranged on the transformer station that at least two wind energy turbine set is collected.Below this structure is specifically described.

Wind power plant cluster controls device 20 and includes: acquisition module 21, detection module 22 and control module 23.

Acquisition module 21, for receiving the voltage instruction that control centre issues, and extracts the grid-connected point voltage of target of at least two wind energy turbine set from voltage instruction.

Detection module 22, is connected to acquisition module 21, for receiving the current grid-connected point voltage that at least two wind energy turbine set is uploaded, and current grid-connected point voltage and pre-set interval is compared, detects the interval at current grid-connected point voltage place.

Control module 23, it is connected to detection module 22, for when current grid-connected point voltage is in properly functioning interval, the AVC substation controlling this wind energy turbine set enters local control model, and the corresponding grid-connected point voltage of target is issued to AVC substation, the grid-connected point voltage being controlled wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of target；When current grid-connected point voltage is in misoperation interval, the AVC substation controlling this wind energy turbine set enters coordination control model, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in wind power plant cluster, control to coordinate AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of target；And when current grid-connected point voltage is in urgent traffic coverage, the AVC substation controlling this wind energy turbine set enters emergent control pattern, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

Power reactive power control system by the wind power plant cluster of the embodiment of the present invention, traffic coverage is preset for wind farm grid-connected point voltage, corresponding different control models, wind power plant cluster is set in the transformer station that each wind energy turbine set is collected and controls device, control centre is assisted jointly to complete the control to wind power plant cluster, coordinate to control that each wind energy turbine set is idle exerts oneself, reducing on the basis of reactive reserve, ensure that the voltage of each wind energy turbine set remains stable for, improve area voltage levvl, optimize the reactive power of large-scale wind power field group.Further, the mode cutting machine, removal of load or wind cutting field is adopted to carry out emergent control, it is to avoid to cause the serious consequences such as the extensive off-grid of wind power plant cluster, system unstability, area power grid collapse of voltage.

Reactive-load compensation equipment can also be set in each wind energy turbine set, for instance SVG or SVC etc..

In one embodiment, control module 23 and include: the first control unit, for adopting below equation to calculate all wind energy turbine set reactive voltage sensitivity coefficient matrix S to being in the wind energy turbine set i coordinating control model in wind power plant cluster:

S=-(B ")^-1V^-1

Wherein, the element S in reactive voltage sensitivity coefficient matrix S_ijThe sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes for wind energy turbine set i；B is " for the admittance matrix of circuit, matrix's reversibility in wind power plant cluster；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；By the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small；Selected and sorted in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as coordinate AVC substation.

In one embodiment, control module 23 and include: the second control unit, for the difference according to the current grid-connected point voltage with the grid-connected point voltage of target that are in the wind energy turbine set coordinating control model, calculate and coordinate the idle adjustment amount that AVC substation needs to provide；Issue, to coordinating AVC substation, the idle coordination control instruction carrying idle adjustment amount, coordinate AVC substation according to idle adjustment amount output reactive power, make the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of target；Wherein, coordinating AVC substation according to after idle adjustment amount output reactive power, the grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

In one embodiment, control module 23 to include: the 3rd control unit, for issuing Reactive-power control instruction in the AVC substation being in emergent control pattern to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, detection reaches deliberate action delay time, the AVC substation controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, deliberate action delay time is more than the action cycle of the AVC substation being in emergent control pattern, action cycle is the Reactive-power control instruction time to Wind turbines or reactive-load compensation equipment execution action that issues from the AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.

Used above, term " unit " or " module " can realize the software of predetermined function and/or the combination of hardware.Although the system described by following example preferably realizes with software, but hardware, or the realization of the combination of software and hardware is also likely to and is contemplated.Certainly, the simply one signal of above-mentioned Module Division divides, and the invention is not limited in this.As long as the Module Division of the purpose of the present invention can be realized, protection scope of the present invention all should be belonged to.

The Reactive Power Control of wind power plant cluster be divided into two-stage, one be this region control, wind energy turbine set substation individually complete.Two is coordinate control, wind power plant cluster each wind energy turbine set controlled in device coordination region completes.Wind power plant cluster controls the control object of device and mainly includes each wind energy turbine set that wind energy turbine set is collected in transformer station and region, substation bus bar voltage-tracing scheduling voltage instruction is collected for target with wind energy turbine set, coordinate the idle output of each wind energy turbine set in region, make full use of the reactive power of wind energy turbine set, it is ensured that the voltage stabilization of cluster regions, large-scale wind power field.Wind power plant cluster control device with the active power and reactive power of the connecting line of higher level load-center substation for controlling target, receive the control command that main website of control centre is assigned, it is achieved active power in region within the jurisdiction and reactive power equilibrium.

For above-mentioned on geographical position contiguous, have identical characteristics and access the wind power plant cluster of same transformer station, carry out unified coordinated management, the randomness of single wind energy turbine set, undulatory property and intermittence can be effectively improved, make it close with normal power supplies in installation scale and outside modulating properties, be conducive to improving responsive electricity grid scheduling and the ability controlled.

In sum, the reactive power control method of the wind power plant cluster of the present invention and system, manage for being collected the region voltage accessing the large-scale wind power field group that same transformer station form by multiple wind energy turbine set.To collect substation bus bar voltage-tracing dispatch command for target, coordinate to control the reactive power of each wind energy turbine set in cluster regions, make full use of the idle resource of each wind energy turbine set, each wind energy turbine set can be supported mutually, make reactive power in region mutually coordinated, while trace scheduling instruction, wind farm grid-connected point voltage is made to be optimized.Collecting transformer station in wind energy turbine set sets up wind power plant cluster to control device, and auxiliary dispatching center carries out cluster regions power coordination control, optimizes area voltage.

Describe in flow chart or in this any process described otherwise above or method and be construed as, represent and include the module of code of executable instruction of one or more step for realizing specific logical function or process, fragment or part, and the scope of the preferred embodiment of the present invention includes other realization, wherein can not press order that is shown or that discuss, including according to involved function by basic mode simultaneously or in the opposite order, performing function, this should be understood by embodiments of the invention person of ordinary skill in the field.

In the description of this specification, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means in conjunction with this embodiment or example describe are contained at least one embodiment or the example of the present invention.In this manual, the schematic representation of above-mentioned term is not necessarily referring to identical embodiment or example.And, the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiments or example.

Particular embodiments described above; the purpose of the present invention, technical scheme and beneficial effect have been further described; it is it should be understood that; the foregoing is only specific embodiments of the invention; the protection domain being not intended to limit the present invention; all within the spirit and principles in the present invention, any amendment of making, equivalent replacement, improvement etc., should be included within protection scope of the present invention.

Claims (10)

1. the reactive power control method of a wind power plant cluster, it is characterised in that including:

Wind power plant cluster controls device and receives the voltage instruction that control centre issues, and from described voltage instruction, extract the grid-connected point voltage of target of each wind energy turbine set in wind power plant cluster, wherein, described wind power plant cluster control device is arranged on the transformer station that each wind energy turbine set described is collected；

Described wind power plant cluster controls device and receives the current grid-connected point voltage that each wind energy turbine set described is uploaded, and described current grid-connected point voltage and pre-set interval is compared, and detects the interval at described current grid-connected point voltage place；

If described current grid-connected point voltage is in properly functioning interval, described wind power plant cluster controls device and controls the local control model of AVC substation entrance of this wind energy turbine set, and issuing the grid-connected point voltage of described target to described AVC substation, the grid-connected point voltage being controlled described wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of described target；

If described current grid-connected point voltage is in misoperation interval, described wind power plant cluster controls device and controls the AVC substation entrance coordination control model of this wind energy turbine set, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in described wind power plant cluster, control described coordination AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target；

If described current grid-connected point voltage is in urgent traffic coverage, described wind power plant cluster controls device and controls the AVC substation entrance emergent control pattern of this wind energy turbine set, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

2. method according to claim 1, it is characterised in that described pre-set interval divides according to wind farm grid-connected point voltage, properly functioning interval isMisoperation interval is $V_{i-\min }^{\mathrm{II}}\&le;V_i\&le;V_{i-\min }^I$ Or $V_{i-\max }^I\&le;V_i\&le;V_{i-\max }^{\mathrm{II}},$ Urgent traffic coverage is $V_i<V_{i-\min }^{\mathrm{II}}$ Or $V_i>V_{i-\max }^{\mathrm{II}},$ Wherein, i represents the numbering of wind energy turbine set, V_iRepresent wind farm grid-connected point voltage,

3. method according to claim 1, it is characterised in that select to coordinate AVC substation in described wind power plant cluster according to the idle variable capacity of reactive voltage sensitivity and each wind energy turbine set and include:

Below equation is adopted to calculate all wind energy turbine set reactive voltage sensitivity coefficient matrix S to being in the wind energy turbine set i coordinating control model in described wind power plant cluster:

S=-(B ")^-1V^-1

Wherein, the element S in reactive voltage sensitivity coefficient matrix S_ijThe sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes for wind energy turbine set i；B is " for the admittance matrix of circuit, matrix's reversibility in described wind power plant cluster；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；

By the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small, and selected and sorted coordinates AVC substation in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as described.

4. method according to claim 1, it is characterised in that control described coordination AVC substation output reactive power, include to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target:

Difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculating described AVC substation of coordinating needs the idle adjustment amount of offer；

The idle coordination control instruction carrying described idle adjustment amount is issued to described coordination AVC substation, described coordination AVC substation, according to described idle adjustment amount output reactive power, makes the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of described target；Wherein, described coordination AVC substation is according to after described idle adjustment amount output reactive power, and the described grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

5. method according to claim 4, it is characterised in that the difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculating described AVC substation of coordinating needs the idle adjustment amount provided to include:

Below equation is adopted to calculate the described idle adjustment amount Δ Q coordinating AVC substation_i:

ΔV_j=S Δ Q_i

Wherein, Δ V_jThe difference of current grid-connected point voltage with the grid-connected point voltage of described target for being in the wind energy turbine set j coordinating control model, idle adjustment amount Δ Q_iWithin the scope of the described variable capacity coordinating AVC substation.

6. method according to claim 1, it is characterised in that adopt the grid-connected point voltage that the mode cutting machine, removal of load or wind cutting field controls this wind energy turbine set to include:

The AVC substation being in emergent control pattern issues Reactive-power control instruction to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, described wind power plant cluster controls device detection and reaches deliberate action delay time, the AVC substation then controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, described deliberate action delay time is more than the action cycle of the described AVC substation being in emergent control pattern, the described action cycle is that Reactive-power control sent instructions to the time of Wind turbines or reactive-load compensation equipment execution action from the described AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.

7. the power reactive power control system of a wind power plant cluster, it is characterized in that, including: control centre, wind power plant cluster control device and wind power plant cluster, wherein, described wind power plant cluster includes the AVC substation of at least two wind energy turbine set and correspondence, and described wind power plant cluster controls device and is arranged on the transformer station that described at least two wind energy turbine set is collected；

Described wind power plant cluster controls device and includes: acquisition module, detection module and control module；

Described acquisition module, for receiving the voltage instruction that described control centre issues, and extracts the grid-connected point voltage of target of described at least two wind energy turbine set from described voltage instruction；

Described detection module, for receiving the current grid-connected point voltage that described at least two wind energy turbine set is uploaded, and compares described current grid-connected point voltage and pre-set interval, detects the interval at described current grid-connected point voltage place；

Described control module, for when described current grid-connected point voltage is in properly functioning interval, the AVC substation controlling this wind energy turbine set enters local control model, and issuing the grid-connected point voltage of described target to described AVC substation, the grid-connected point voltage being controlled described wind energy turbine set by reactive power compensation reaches the grid-connected point voltage of described target；When described current grid-connected point voltage is in misoperation interval, the AVC substation controlling this wind energy turbine set enters coordination control model, idle variable capacity according to reactive voltage sensitivity and each wind energy turbine set selects to coordinate AVC substation in described wind power plant cluster, control described coordination AVC substation output reactive power, to assist the grid-connected point voltage controlling to be in the wind energy turbine set coordinating control model to reach the grid-connected point voltage of described target；And when described current grid-connected point voltage is in urgent traffic coverage, the AVC substation controlling this wind energy turbine set enters emergent control pattern, adopts the mode cutting machine, removal of load or wind cutting field to control the grid-connected point voltage of this wind energy turbine set.

8. system according to claim 7, it is characterised in that described control module includes:

First control unit, for adopting below equation to calculate all wind energy turbine set reactive voltage sensitivity coefficient matrix S to being in the wind energy turbine set i coordinating control model in described wind power plant cluster:

S=-(B ")^-1V^-1

Wherein, the element S in reactive voltage sensitivity coefficient matrix S_ijThe sensitivity coefficient that grid-connected point voltage changes wind energy turbine set j's and site reactive power changes for wind energy turbine set i；B is " for the admittance matrix of circuit, matrix's reversibility in described wind power plant cluster；V=diag (V₁,V₂,...,V_n) represent Wind turbines set end voltage, total n node；By the sensitivity coefficient S in reactive voltage sensitivity coefficient matrix S_ijAccording to being ranked up from big to small；Selected and sorted coordinates AVC substation in the AVC substation of the wind energy turbine set corresponding to sensitivity coefficient above as described.

9. system according to claim 7, it is characterised in that described control module includes:

Second control unit, for the difference according to the current grid-connected point voltage with the grid-connected point voltage of described target that are in the wind energy turbine set coordinating control model, calculates the idle adjustment amount that described coordination AVC substation needs to provide；The idle coordination control instruction carrying described idle adjustment amount is issued to described coordination AVC substation, described coordination AVC substation, according to described idle adjustment amount output reactive power, makes the grid-connected point voltage being in the wind energy turbine set coordinating control model reach the grid-connected point voltage of described target；Wherein, described coordination AVC substation is according to after described idle adjustment amount output reactive power, and the described grid-connected point voltage coordinating wind energy turbine set corresponding to AVC substation is in properly functioning interval.

10. system according to claim 7, it is characterised in that described control module includes:

3rd control unit, for issuing Reactive-power control instruction in the AVC substation being in emergent control pattern to the Wind turbines in this wind energy turbine set or after reactive-load compensation equipment, detection reaches deliberate action delay time, the AVC substation controlling to be in emergent control pattern carries out cutting machine, removal of load or wind cutting field, wherein, described deliberate action delay time is more than the action cycle of the described AVC substation being in emergent control pattern, the described action cycle is to issue the Reactive-power control instruction time to Wind turbines or reactive-load compensation equipment execution action from the described AVC substation being in emergent control pattern；Wherein, if wind farm grid-connected point voltage is in the given time always above the peak set, confirming that reactive power compensation planning is used up, that excises this wind energy turbine set sends circuit.