CN202178583U - Reactive power control system of wind power station - Google Patents

Abstract

The utility model discloses a reactive power control system of a wind power station. A voltage of a high-voltage-side bus of the wind power station is taken as a control target. A reactive power is taken as a regulation volume. According to a fluctuation range and power factors of the voltage of the high-voltage-side bus of the wind power station, a voltage control strategy and a power factor control strategy of the wind power station are selected, or the control system is forced to output a constant value. And according to a reactive power reference value needed to the output in the wind power station, reactive power output values of each fan and centralized reactive-load compensation device in the wind power station are determined. By adopting the technical scheme in the utility model, the need of the system is met by utilizing the reactive output of inter-connected points of the wind power station, so as to inhibit the fluctuation of the bus voltage and regulate the power factors of the wind power station, and coordinately control the reactive output of each fan unit and centralized reactive-load compensation device in the wind power station.

Description

A kind of wind energy turbine set power reactive power control system

Technical field

The utility model relates to technical field of wind power generation, relates in particular to a kind of wind energy turbine set power reactive power control system.

Background technology

Wind energy is at random with uncontrollable, and the power and the also random fluctuation of voltage of blower fan output are interference sources to metastable electric power system.The large-scale wind power field is concentrated to be incorporated into the power networks and has been brought a series of far-reaching influences to the safe operation and the economic dispatch of electric power system, and wherein voltage-idle problem of causing of wind energy turbine set is to cause concern the earliest, also is one of problem the most common in the actual motion.

Early stage wind energy turbine set is carried out idle control through opening-closing capacitor bank to wind energy turbine set.Under the more weak situation of electric network composition, receive the influence of wind energy change at random, only lean on these capacitor groups can not catch up with the influence of wind speed to electrical network.At present, newly-built wind energy turbine set has mostly disposed dynamic reactive compensation device, like SVC, SVG etc., to improve the dynamic responding speed that reactive power is regulated.Wind energy turbine set disposes the reactive power compensator of suitable capacity, and controls and manage according to system requirements, can effectively improve the stable of wind energy turbine set output voltage, reduces the disturbance of wind-powered electricity generation to electrical network, and improves the fault ability of reply wind energy turbine set.

Development along with wind power technology; Variable speed constant frequency wind-powered electricity generation unit becomes (mainly comprising variable speed constant frequency doubly-fed unit and total power converter blower fan) mainstream model of grid connected wind power field gradually; These types adopt four-quadrant high-power electric and electronic current transformer to be connected with electrical network; Control through current transformer can realize gaining merit, idle decoupling zero is controlled, and possesses the ability of the idle output of dynamic adjustments.Aspect double-fed variable speed constant frequency wind-powered electricity generation unit, the GE company of the U.S. has developed the idle control product of wind energy turbine set " WindVAR ", the electronic-controlled installation through WindVAR system and unit self cooperate the voltage of control wind energy turbine set.

The WindVAR system is to be control unit with GE wind-powered electricity generation unit; Through the point voltage that is incorporated into the power networks in the collection of unit line attachment; Compare with the reference voltage of setting and to obtain the real-time voltage deviation, ask for real-time reactive power compensation amount through the PI controller again, compensation rate is handed down to the wind-powered electricity generation unit.The WindVAR system of GE can guarantee the output reactive power real-time tracking access point change in voltage of wind-powered electricity generation unit; But it is a control unit with the wind-powered electricity generation unit; Shortage is to the idle unified planning of whole wind electric field, and the autonomous control of wind-powered electricity generation unit may form bigger reactive power trend between the wind-powered electricity generation unit; Even some unit reactive power fan-out capability is reached capacity, reduce the stable of windfarm system.

Application number is that 201010172546.7 Chinese utility application " control method for coordinating of wind energy turbine set reactive voltage " discloses a kind of wind energy turbine set reactive power method; This method serves as the adjustment reference quantity with wind farm grid-connected some reactive power, but does not provide the computational methods of reactive power reference quantity.In addition, it does not consider the centralized reactive-load compensation equipment in the wind energy turbine set on the command assignment of reactive power, if unit output reactive power is only arranged, possibly can't satisfy the needs of system, and cause the waste of equipment.

The utility model content

The purpose of the utility model is to propose a kind of wind energy turbine set power reactive power control system; Make the idle output of wind farm grid-connected point satisfy the demand of system; With the fluctuation that suppresses busbar voltage with regulate the wind energy turbine set power factor, and coordinate the idle output of every typhoon group of motors and centralized reactive-load compensation equipment in the control wind energy turbine set.

For reaching this purpose, the utility model adopts following technical scheme:

A kind of wind energy turbine set power reactive power control system; Comprise the given module of reference value, the dotted state that is incorporated into the power networks acquisition module, reactive source state acquisition module, wind energy turbine set control mode decision-making module, the wind energy turbine set level is idle allocation strategy module, wind mill group is idle allocation strategy module, reactive-load compensation equipment is idle allocation strategy module, blower fan, centralized reactive-load compensation equipment and and the site; Wherein, The given module of reference value is connected with the dispatching of power netwoks communication interface; The dotted state that is incorporated into the power networks acquisition module with and the site be connected; The given module of reference value, the dotted state that is incorporated into the power networks acquisition module and reactive source state acquisition module are connected with wind energy turbine set control mode decision-making module respectively; Wind energy turbine set control mode decision-making module is connected with the idle allocation strategy module of wind energy turbine set level; Allocation strategy module that the wind energy turbine set level is idle is connected with the idle allocation strategy module of reactive-load compensation equipment with the idle allocation strategy module of wind mill group respectively, allocation strategy module that wind mill group is idle be no less than 1 blower fan and be connected, allocation strategy module that reactive-load compensation equipment is idle is connected with centralized reactive-load compensation equipment; Blower fan and centralized reactive-load compensation equipment respectively with and the site be connected, blower fan also is connected with the reactive source state acquisition module respectively with centralized reactive-load compensation equipment.

Adopted the technical scheme of the utility model; Can be controlled target with wind energy turbine set high-voltage side bus voltage; With reactive power as adjustment amount; Select wind energy turbine set voltage control strategy, power factor controlling strategy or force the idle steady state value that is output as of control system according to the fluctuation range of wind energy turbine set busbar voltage and power factor, and according to the reactive power reference qref of wind energy turbine set needs output, confirm the reactive power output valve of every typhoon machine and centralized reactive-load compensation equipment in the wind energy turbine set.The utility model technical scheme can suppress the wind energy turbine set voltage fluctuation that the one's respective area load causes; Regulate the requirement that power factor satisfies electrical network; Reactive power output in the unified control wind energy turbine set; And the running status of coordination wind-powered electricity generation unit and reactive-load compensation equipment, fully play the stable effect of windfarm system of keeping.It is relevant with the running status of unit that the utility model technical scheme has fully taken into account the idle output characteristic of unit; Idle output maximum with unit is that every typhoon machine distributes the reactive power instruction as foundation; Given full play to the idle fan-out capability of each unit, the fail safe that has improved equipment.

Description of drawings

Fig. 1 is the structural representation of wind energy turbine set power reactive power control system in the utility model embodiment.

Fig. 2 is a wind energy turbine set power reactive power control system control flow chart in the utility model embodiment.

Embodiment

Further specify the technical scheme of the utility model below in conjunction with accompanying drawing and through embodiment.

Fig. 1 is the structural representation of wind energy turbine set power reactive power control system in the utility model embodiment.As shown in Figure 1, allocation strategy module 105 that this wind energy turbine set power reactive power control system comprises the given module of reference value 101, the dotted state that is incorporated into the power networks acquisition module 102, reactive source state acquisition module 103, wind energy turbine set control mode decision-making module 104, the wind energy turbine set level is idle, wind mill group is idle allocation strategy module 106, reactive-load compensation equipment is idle allocation strategy module 107, blower fan 108, centralized reactive-load compensation equipment 109 and and site 110.

Wherein, The given module of reference value is connected with dispatching of power netwoks communication interface 111; The dotted state that is incorporated into the power networks acquisition module with and the site be connected; The given module of reference value, the dotted state that is incorporated into the power networks acquisition module and reactive source state acquisition module are connected with wind energy turbine set control mode decision-making module respectively, and wind energy turbine set control mode decision-making module is connected with the idle allocation strategy module of wind energy turbine set level, and allocation strategy module that the wind energy turbine set level is idle is connected with the idle allocation strategy module of reactive-load compensation equipment with the idle allocation strategy module of wind mill group respectively; Allocation strategy module that wind mill group is idle be no less than 1 blower fan and be connected; Allocation strategy module that reactive-load compensation equipment is idle is connected with centralized reactive-load compensation equipment, blower fan and centralized reactive-load compensation equipment respectively with and the site be connected, blower fan also is connected with the reactive source state acquisition module respectively with centralized reactive-load compensation equipment.

Fig. 2 is a wind energy turbine set power reactive power control system control flow chart in the utility model embodiment.As shown in Figure 2, the control flow of this wind energy turbine set power reactive power control system may further comprise the steps:

Step 201, measure the voltage U of wind farm grid-connected point in real time _Mea, active power P _MeaAnd reactive power Q _Mea, and will measure the voltage U that obtains _MeaNominal voltage U with wind farm grid-connected some busbar voltage _RefDifference be set to voltage deviation Δ U, simultaneously according to active power P _MeaAnd reactive power Q _MeaCalculate the also actual power factor λ of site _Mea

Step 202, the requirement of voltage and power factor deviation is provided with the dead band threshold value of voltage deviation Δ U and the dead band threshold value of power factor deviation delta λ according to electrical network.

Step 203, at first judge that voltage deviation Δ U is whether in the dead band threshold range of voltage deviation Δ U; Next judges that power factor deviation delta λ is whether in the dead band threshold range of power factor deviation delta λ; If voltage deviation Δ U is not in the dead band threshold range of voltage deviation Δ U; Then go to step 204, if voltage deviation Δ U in the dead band threshold range of voltage deviation Δ U and power factor deviation delta λ not in the dead band threshold range of power factor deviation delta λ, then go to step 205; If voltage deviation Δ U in the dead band threshold range of voltage deviation Δ U and power factor deviation delta λ in the dead band threshold range of power factor deviation delta λ, then control the idle output of wind energy turbine set powerless control system Q _WFrefEqual detected and the site reactive power Q _Mea, and go to step 206.

Step 204, wind energy turbine set voltage control module are imported voltage deviation Δ U the proportionality coefficient K of regulation voltage deviation _SlopeModule obtains reactive power reference qref Q _Ref, reactive power reference qref Q _RefWith reactive power Q _MeaDifference handle total reactive power value Q that the back need be exported as wind energy turbine set through pi regulator _WFref, and go to step 206.Wherein, the proportionality coefficient K of regulation voltage deviation _SlopeModule is advanced to realize according to idle coefficient of sensitivity.

Step 205, wind energy turbine set power factor controlling module are according to the power factor of electrical network requirement and the active power P of actual measurement _Mea, obtain reactive power reference qref Q _Ref, reactive power reference qref Q _RefWith reactive power Q _MeaDifference handle total reactive power value Q that the back need be exported as wind energy turbine set through pi regulator _WFref, and go to step 206.

In step 204 and the step 205, the adjusting range K of pi regulator realizes according to response speed and control precision, satisfies following formula:

$Q_{\mathrm{WFref}}=K(\mathrm{\Δ\; Q}\left(t\right)+\frac{1}{T}\underset{0}{\overset{T}{\∫}}\mathrm{\Δ\; Q}\left(t\right)\mathrm{Dt}),$ Wherein T is an integration time constant.

In step 204 and the step 205, the maximum idle output valve of the expection of wind energy turbine set is Q under this operating condition in the pi regulator _WFmaxWith the expection minimum idle output valve be Q _WFmin, the idle reference value of wind energy turbine set is limited in the maximum idle output valve Q of expection _WFmaxWith the minimum idle output valve Q of expection _WFminBetween the two, Q wherein _WFmaxBe the maximum idle output of expection of all blower fans and the maximum idle output sum of expection of centralized reactive-load compensation equipment, Q _WFmaxBe the minimum idle output of expection of all blower fans and the minimum idle output sum of expection of centralized reactive-load compensation equipment.

Step 206, according to the P-Q characteristic of blower fan real time execution operating mode and blower fan, calculate total reactive power output stage limit value Q of wind energy turbine set inner blower _Max, and calculate total reactive power value Q that wind energy turbine set need be exported _WFrefWith total reactive power output stage limit value Q _MaxDifference DELTA Q _WFref, if difference DELTA Q _WFrefGreater than zero, the wind energy turbine set inner blower total idle command value Q that need export then _TrefBe set to total reactive power value Q that wind energy turbine set need be exported _WFrefIf difference DELTA Q _WFrefLess than zero, the blower fan total idle command value Q that need export then _TrefBe set to total reactive power output stage limit value Q _Max, the idle instruction of centralized reactive-load compensation equipment output is total reactive power value Q that wind energy turbine set need be exported in the wind energy turbine set _WFrefWith total reactive power output stage limit value Q _MaxDifference DELTA Q _WFref, and difference DELTA Q _WFrefBe no more than the centralized reactive-load compensation equipment capacity of being furnished with in the wind energy turbine set.

Step 207, wind mill group is idle allocation strategy module are distributed reactive power to every typhoon machine, wherein the blower fan reactive power of i platform output reference value Q _IrefComputing formula as shown in the formula:

$Q_{\mathrm{ifef}}=\frac{Q_{i\max }}{Q_{\max }}\·Q_{\mathrm{Tref}},$

Wherein Q _ImaxBe the maximum reactive power output valve of expection of i typhoon machine, Q _MaxBe the total reactive power output stage of wind energy turbine set limit value, Q _TrefBe the total idle command value that the wind energy turbine set inner blower need be exported, n is a wind electric field blower platform number.

The above; Be merely the preferable embodiment of the utility model; But the protection range of the utility model is not limited thereto; Anyly be familiar with this technological people in the technical scope that the utility model disclosed, the variation that can expect easily or replacement all should be encompassed within the protection range of the utility model.Therefore, the protection range of the utility model should be as the criterion with the protection range of claim.

Claims (1)

1. wind energy turbine set power reactive power control system; It is characterized in that; Comprise the given module of reference value, the dotted state that is incorporated into the power networks acquisition module, reactive source state acquisition module, wind energy turbine set control mode decision-making module, the wind energy turbine set level is idle allocation strategy module, wind mill group is idle allocation strategy module, reactive-load compensation equipment is idle allocation strategy module, blower fan, centralized reactive-load compensation equipment and and the site; Wherein, The given module of reference value is connected with the dispatching of power netwoks communication interface; The dotted state that is incorporated into the power networks acquisition module with and the site be connected; The given module of reference value, the dotted state that is incorporated into the power networks acquisition module and reactive source state acquisition module are connected with wind energy turbine set control mode decision-making module respectively, and wind energy turbine set control mode decision-making module is connected with the idle allocation strategy module of wind energy turbine set level, and allocation strategy module that the wind energy turbine set level is idle is connected with the idle allocation strategy module of reactive-load compensation equipment with the idle allocation strategy module of wind mill group respectively; Allocation strategy module that wind mill group is idle be no less than 1 blower fan and be connected; Allocation strategy module that reactive-load compensation equipment is idle is connected with centralized reactive-load compensation equipment, blower fan and centralized reactive-load compensation equipment respectively with and the site be connected, blower fan also is connected with the reactive source state acquisition module respectively with centralized reactive-load compensation equipment.

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