CN106655203A - Sensitivity-based reactive power regulation priority selection method of wind farms - Google Patents

Abstract

The invention discloses a sensitivity-based reactive power regulation priority selection method of wind farms. The method mainly comprises the step of solving the sensitivity between grid connection point voltage of one wind farm and output reactive power of the adjacent wind farm through reactive power-voltage sensitivity matrixes and a node power balance equation, thereby obtaining a priority sequence of actions of the wind farms for large-scale on-site reactive power voltage regulation and mutual compensation. Therefore, the problems of on-site reactive power control disorder, delay and the like of a wind farm group in the prior art can be solved.

Description

A kind of wind energy turbine set Reactive-power control priority system of selection based on sensitivity

Technical field

The present invention relates to reactive voltage regulation technology field in the extensive access system of new forms of energy, in particular it relates to a kind of Wind energy turbine set Reactive-power control priority system of selection based on sensitivity.

Background technology

China's new forms of energy large-scale cluster formula development, brings many challenges for electrical network.In recent years with wind Electric grid connection capacity is ramped, and the operation of thing followed reactive voltage and control problem are also more complicated.By to different wind-powered electricity generations The reactive voltage characteristic research of unit and various reactive-load compensation equipments can be seen that the nothing of the electrical network accessed for large-scale wind power The control of work(voltage needs the mutual cooperation of wind energy turbine set.

During the present invention is realized, inventor has found at least there is following defect in prior art:Firstly for big The system that scale wind-powered electricity generation is incorporated to, when reactive voltage is controlled on the spot, reactive-load compensation equipment tends not to meet voltage stabilization operation Require；Secondly in addition to squirrel-cage Wind turbines, other Wind turbines are respectively provided with good reactive power compensation planning, but idle benefit Repay capacity less；The system that large-scale wind power field cluster is connected to the grid, during many Wind turbines input reactive power/voltage controls one is needed badly Coordination control strategy is covered to realizing the mutual cooperation between wind energy turbine set.

The content of the invention

It is an object of the present invention to be directed to the problems referred to above, propose that a kind of wind energy turbine set Reactive-power control based on sensitivity is preferential Level system of selection, to obtaining the sensitivity system of certain wind farm grid-connected busbar voltage and the wind energy turbine set output reactive power of its phase Number, to realize the mutual cooperation when reactive voltage is controlled on the spot between wind energy turbine set.

For achieving the above object, the technical solution used in the present invention is：A kind of wind energy turbine set Reactive-power control based on sensitivity Priority system of selection, mainly includes：

Step 1：Calculate trend and list node power equilibrium equation；

Step 2：By to variable partitions in node power equation be disturbance variable, state variable, control variables, obtain spirit Sensitive matrix S_xu, S_xp；

Step 3：The voltage of wind energy turbine set i is tried to achieve with regard to wind energy turbine set j by sensitivity matrix and node power equilibrium equation The sensitivity S of output reactive power change₁With the voltage of wind energy turbine set j with regard to the sensitive of the output reactive power change of wind energy turbine set j Degree S₂；It is final to obtain large-scale wind power field by obtaining the sensitivity that wind farm grid-connected point voltage is adjacent between wind energy turbine set Reactive voltage is adjusted on the spot, mutually the priority orders of the wind energy turbine set action of compensation.

Further, in step 1, the calculation procedure of the node power equilibrium equation includes：

If the generator power of power system interior joint i is P_Gi+jQ_Gi, load power is P_LDi+jQ_LDi, with polar coordinates table When showing node voltage, the power balance equation of node is：

ΔP_i=P_Gi-P_LDi-U_i∑U_j(G_ijcosδ_ij+B_ijsinδ_ij)=0

ΔQ_i=Q_Gi-Q_LDi-U_i∑U_j(G_ijsinδ_ij-B_ijcosδ_ij)=0 (1)

In formula (1), Δ P_i,ΔQ_iTo inject the active power and reactive power of node i；

P_Gi,Q_GiTo inject the generator active power and reactive power of node i；

P_LDi,Q_LDiTo inject the load active power and reactive power of node i；

U_i,U_jFor the voltage of node i；

G_ij+jB_ijFor the admittance between node i, j；

δ_ijFor the phase difference of voltage between node i, j, δ_ij=δ_i-δ_j。

Further, in step 2, the S of sensitivity matrix is obtained_xu, S_xpCalculation procedure include：

If representing disturbance variable, control variables and state variable, power system node power equilibrium equation respectively with p, u, x It is represented by：

F (x, u, p)=0 (2)

P --- disturbance variable in formula (2)；

U --- control variables；

X --- state variable；

If comprising wind energy turbine set area operation under state (x (0), u (0), p (0)), as a certain wind energy turbine set is active fluctuation is gone out Δ p, conventional generator has been corresponding adjustment Δ u, and system accordingly there occurs that state deviates Δ x, then the power-balance side of system Cheng Yingwei：

f(x⁽⁰⁾+Δx,u⁽⁰⁾+Δu,p⁽⁰⁾+ Δ p)=0 (3)

X (0) in formula, u (0), p (0) --- system running state, bus run voltage, wind energy turbine set is active to exert oneself；

Δ x --- system state change amount；

Δ u --- voltage variety；

Δ p --- the active variable quantity of exerting oneself of wind energy turbine set；

Assume that each variable is varied less under stable situation, so that the items of negligible its second order and the above, then formula (3) can It is to launch abbreviation：

In formula (4)It is Jacobian matrix；

Will be based on state (x (0), u (0), p (0))Matrix,Matrix andMatrix is abbreviated as respectively J_x、J_u And J_p, then have

J_xΔx+J_uΔu+J_pΔ p=0 (5)

J in formula_x、J_u、J_pIt is Jacobian matrix；

Above formula (5) is referred to as sensitivity equation, and by the formula deviation value of state variable can be solved：

In formulaFor sensitivity matrix；

For sensitivity matrix.

Further, in step 3, the Calculation of Sensitivity step that wind farm grid-connected point voltage is adjacent between wind energy turbine set is obtained Suddenly include：

If J is the full rank Jacobian matrix of system polar form, Δ Y and Δ X is respectively system injection variable quantity and shape State variable quantity, is divided into two parts, i.e., by Δ Y：Δ Y=[Δ Y_IΔY_N]^T, corresponding Δ X is then changed into Δ X=[Δ X_IΔX_N]^T, phase Answer ground that J is divided into into 4 parts, i.e.,：

J in formula (7)_II、J_IN、J_NI、J_NN--- the full rank Jacobian matrix in part,

Relation between injection rate and amount of state variation is

In formula (8),

ΔY_I--- controlled wind energy turbine set accesses the injection variable quantity of regional node；

ΔX_I--- controlled wind energy turbine set accesses the amount of state variation of regional node；

ΔY_N--- the injection variable quantity of remaining node；

ΔX_N--- the amount of state variation of remaining node,

If Δ Y_N=0, that is, the amount of being actually implanted into only include Δ Y_I, then can be released by formula (8)：

Due to J_NNIt is nonsingular so as to can obtain：

To J_SIInvert：

Then the relation between the node of controlled wind energy turbine set access point area is

Δ U in formula_w--- the voltage of wind energy turbine set Egress node；

Δθ_w--- the phase angle change vector of wind energy turbine set Egress node；

ΔU_c--- the voltage of access point；

Δθ_c--- the phase angle change vector of access point；

ΔP_W--- wind energy turbine set Egress node injects active change vector；

ΔQ_W--- wind energy turbine set Egress node injects idle change vector；

ΔP_C--- access point injects active change vector；

ΔQ_C--- access point injects idle change vector,

Reactive power and the sensitivity relation of voltage, then can obtain the voltage of wind energy turbine set i with regard to wind by formula (12) and formula (13) Electric field j output reactive power change sensitivity relation be

S₁=A_2m+n+i,m+n+j (14)

S in formula (14)₁--- the sensitivity that the voltage of wind energy turbine set i changes with regard to the output reactive power of wind energy turbine set j.

The voltage of wind energy turbine set j with regard to wind energy turbine set j output reactive power change sensitivity relation be

S₂=A_m+j,m+n+j (15)

S in formula (15)₂--- the sensitivity that the voltage of wind energy turbine set j changes with regard to the output reactive power of wind energy turbine set j.

A kind of wind energy turbine set Reactive-power control priority system of selection based on sensitivity of various embodiments of the present invention, due to main Including：Wind farm grid-connected point voltage is tried to achieve by idle-voltage sensibility matrix and node power equilibrium equation and is adjacent wind Sensitivity between electric field, you can obtain large-scale wind power field reactive voltage and adjust on the spot, the wind energy turbine set action for compensating mutually Priority orders；Such that it is able to overcome the problems such as prior art wind electric field group is idle to control on the spot unordered, delayed.

Other features and advantages of the present invention will be illustrated in the following description, also, the partly change from specification Obtain it is clear that or being understood by implementing the present invention.

Below by embodiment, technical scheme is described in further detail.

Specific embodiment

Below in conjunction with illustrating to the preferred embodiments of the present invention, it will be appreciated that preferred embodiment described herein The present invention is merely to illustrate and is explained, is not intended to limit the present invention.

Specifically, based on the wind energy turbine set priority back-and-forth method of sensitivity be due to it is different perform that stations send it is idle to grid-connected Point voltage response characteristic is different.Therefore, the core of system voltage control can be quickly and accurately participated in as far as possible in order to allow perform to stand The heart is exactly can to estimate the interdependent node voltage change that the change of wind energy turbine set output reactive power causes, i.e., spirit between the two Sensitivity relation.After calculating sensitivity coefficient, selection performs station to grid entry point busbar voltage sensitivity highest.Mainly include：

The first step：Node power equilibrium equation；If the generator power of power system interior joint i is P_Gi+jQ_Gi, load work( Rate is P_LDi+jQ_LDi, during with polar coordinate representation node voltage, the power balance equation of node is

ΔP_i=P_Gi-P_LDi-U_i∑U_j(G_ijcosδ_ij+B_ijsinδ_ij)=0

ΔQ_i=Q_Gi-Q_LDi-U_i∑U_j(G_ijsinδ_ij-B_ijcosδ_ij)=0 (1)

In formula：

ΔP_i,ΔQ_i--- the active power and reactive power of injection node i；

P_Gi,Q_Gi--- the generator active power and reactive power of injection node i；

P_LDi,Q_LDi--- the load active power and reactive power of injection node i；

U_i,U_j--- the voltage of node i；

G_ij+jB_ij--- the admittance between node i, j；

δ_ij--- the phase difference of voltage between node i, j, δ_ij=δ_i-δ_j。

Second step：Sensitivity equation, obtains sensitivity matrix；If with p, u, x represent respectively disturbance variable, control variables and State variable.Power system node power equilibrium equation is represented by：

F (x, u, p)=0 (2)

P in formula --- disturbance variable；

U --- control variables；

X --- state variable.

If comprising wind energy turbine set area operation under state (x (0), u (0), p (0)), as a certain wind energy turbine set is active fluctuation is gone out Δ p, conventional generator has been corresponding adjustment Δ u, and system accordingly there occurs that state deviates Δ x, then the power-balance side of system Cheng Yingwei：

f(x⁽⁰⁾+Δx,u⁽⁰⁾+Δu,p⁽⁰⁾+ Δ p)=0 (3)

X (0) in formula, u (0), p (0) --- system running state, bus run voltage, wind energy turbine set is active to exert oneself；

Δ x --- system state change amount；

Δ u --- voltage variety；

Δ p --- the active variable quantity of exerting oneself of wind energy turbine set.

Assume that each variable is varied less under stable situation, so that the items of negligible its second order and the above, then formula 3-10 Abbreviation can be launched is：

In formula--- Jacobian matrix.

Such as will be based on state (x (0), u (0), p (0))Matrix is abbreviated as respectively J_x、J_u、 J_p, then have

J_xΔx+J_uΔu+J_pΔ p=0 (5)

J in formula_x、J_u、J_p--- Jacobian matrix.

Above formula is referred to as sensitivity equation, and by the formula deviation value of state variable can be solved：

In formula--- sensitivity matrix；

--- sensitivity matrix.

3rd step：The sensitivity of grid-connected point voltage and reactive source output reactive power

For the control variables or disturbance variable of any given variable quantity, the change of each state variable can be tried to achieve using above formula Change amount.

Said method is applied to into power system, idle-voltage sensibility matrix is tried to achieve.Part of nodes is only focused on herein, By the reactive-load compensation mount point in power system, load bus and generator node as injection node, by full rank Jacobi square Battle array carries out depression of order, and specific acquiring method is as follows：

If J is the full rank Jacobian matrix of system polar form, Δ Y and Δ X is respectively system injection variable quantity and shape State variable quantity, is divided into two parts, i.e., by Δ Y：Δ Y=[Δ Y_IΔY_N]^T, corresponding Δ X is then changed into Δ X=[Δ X_IΔX_N]^T.Phase Answer ground that J is divided into into 4 parts, i.e.,：

J in formula_II、J_IN、J_NI、J_NN--- the full rank Jacobian matrix in part.

Relation between injection rate and amount of state variation is

Δ Y in formula_I--- controlled wind energy turbine set accesses the injection variable quantity of regional node；

ΔX_I--- controlled wind energy turbine set accesses the amount of state variation of regional node；

ΔY_N--- the injection variable quantity of remaining node；

ΔX_N--- the amount of state variation of remaining node.

If Δ Y_N=0, that is, the amount of being actually implanted into only include Δ Y_I, then can be released by formula 3-15：

Due to J_NNIt is nonsingular so as to can obtain：

To J_SIInvert：

Then the relation between the node of controlled wind energy turbine set access point area is

Δ U in formula_w--- the voltage of wind energy turbine set Egress node；

Δθ_w--- the phase angle change vector of wind energy turbine set Egress node；

ΔU_c--- the voltage of access point；

Δθ_c--- the phase angle change vector of access point；

ΔP_W--- wind energy turbine set Egress node injects active change vector；

ΔQ_W--- wind energy turbine set Egress node injects idle change vector；

ΔP_C--- access point injects active change vector；

ΔQ_C--- access point injects idle change vector.

The sensitivity relation of reactive power and voltage is only studied herein, then wind energy turbine set i can be obtained by formula (12) and formula (13) Voltage with regard to wind energy turbine set j output reactive power change sensitivity relation be

S₁=A_2m+n+i,m+n+j (14)

S in formula₁--- the sensitivity that the voltage of wind energy turbine set i changes with regard to the output reactive power of wind energy turbine set j.

The voltage of wind energy turbine set j with regard to wind energy turbine set j output reactive power change sensitivity relation be

S₂=A_m+j,m+n+j (15)

S in formula₂--- the sensitivity that the voltage of wind energy turbine set j changes with regard to the output reactive power of wind energy turbine set j.

Following beneficial effect can at least be reached：First when certain Reactive Compensation in Wind Farm equipment is used up, can also utilize Wind turbines carry out reactive-load compensation, used as the last line of defense of reactive power/voltage control；Secondly by the wind-powered electricity generation based on sensitivity Field Reactive-power control priority system of selection, reactive voltage between a set of wind energy turbine set is proposed to large-scale wind power field group and coordinates control Method, to reaching high efficiency and the rapidity that wind power plant reactive voltage is controlled on the spot.

Finally it should be noted that：The preferred embodiments of the present invention are the foregoing is only, the present invention is not limited to, Although being described in detail to the present invention with reference to the foregoing embodiments, for a person skilled in the art, it still may be used To modify to the technical scheme described in foregoing embodiments, or equivalent is carried out to which part technical characteristic. All any modification, equivalent substitution and improvements within the spirit and principles in the present invention, made etc., should be included in the present invention's Within protection domain.

Claims (4)

1. a kind of wind energy turbine set Reactive-power control priority system of selection based on sensitivity, it is characterised in that comprise the following steps：

Step 1：Calculate trend and list node power equilibrium equation；

Step 2：By to variable partitions in node power equation be disturbance variable, state variable, control variables, obtain sensitivity Matrix S_xu, S_xp；

Step 3：The output of the voltage with regard to wind energy turbine set j of wind energy turbine set i is tried to achieve by sensitivity matrix and node power equilibrium equation The sensitivity S of reactive power change₁The sensitivity S changed with regard to the output reactive power of wind energy turbine set j with the voltage of wind energy turbine set j₂； It is final to obtain extensive by obtaining the sensitivity that wind farm grid-connected point voltage is adjacent between wind energy turbine set output reactive power Wind power plant reactive voltage is adjusted on the spot, mutually the priority orders of the wind energy turbine set action of compensation.

2. the wind energy turbine set Reactive-power control priority system of selection based on sensitivity according to claim 1, it is characterised in that In step 1, the calculation procedure of the node power equilibrium equation includes：

If the generator power of power system interior joint i is P_Gi+jQ_Gi, load power is P_LDi+jQ_LDi, with polar coordinate representation node During voltage, the power balance equation of node is：

ΔP_i=P_Gi-P_LDi-U_iΣU_j(G_ijcosδ_ij+B_ijsinδ_ij)=0

ΔQ_i=Q_Gi-Q_LDi-U_iΣU_j(G_ijsinδ_ij-B_ijcosδ_ij)=0 (1)

In formula (1), Δ P_i,ΔQ_iTo inject the active power and reactive power of node i；

P_Gi,Q_GiTo inject the generator active power and reactive power of node i；

P_LDi,Q_LDiTo inject the load active power and reactive power of node i；

U_i,U_jFor the voltage of node i；

G_ij+jB_ijFor the admittance between node i, j；

δ_ijFor the phase difference of voltage between node i, j, δ_ij=δ_i-δ_j。

3. the wind energy turbine set Reactive-power control priority system of selection based on sensitivity according to claim 2, it is characterised in that In step 2, the S of sensitivity matrix is obtained_xu, S_xpCalculation procedure include：

If representing disturbance variable, control variables and state variable respectively with p, u, x, power system node power equilibrium equation can table It is shown as：

F (x, u, p)=0 (2)

P --- disturbance variable in formula (2)；

U --- control variables；

X --- state variable；

If comprising wind energy turbine set area operation under state (x (0), u (0), p (0)), as a certain wind energy turbine set is active fluctuation Δ p is gone out, Conventional generator has been corresponding adjustment Δ u, and system accordingly there occurs that state deviates Δ x, then the power balance equation of system should For：

f(x⁽⁰⁾+Δx,u⁽⁰⁾+Δu,p⁽⁰⁾+ Δ p)=0 (3)

X (0) in formula, u (0), p (0) --- system running state, bus run voltage, wind energy turbine set is active to exert oneself；

Δ x --- system state change amount；

Δ u --- voltage variety；

Δ p --- the active variable quantity of exerting oneself of wind energy turbine set；

Assume that each variable is varied less under stable situation, so that the items of negligible its second order and the above, then formula (3) can be opened up Letter of becoming civilized is：

$\frac{\∂f}{\∂x}{|}_0\mathrm{\Δ}x+\frac{\∂f}{\∂u}{|}_0\mathrm{\Δ}u+\frac{\∂f}{\∂p}{|}_0\mathrm{\Δ}p=0---\left(4\right)$

In formula (4)It is Jacobian matrix；

Will be based on state (x (0), u (0), p (0))Matrix,Matrix andMatrix is abbreviated as respectively J_x、J_uWith J_p, then have

J_xΔx+J_uΔu+J_pΔ p=0 (5)

J in formula_x、J_u、J_pIt is Jacobian matrix；

Above formula (5) is referred to as sensitivity equation, and by the formula deviation value of state variable can be solved：

$\mathrm{\Δ}x=-J_x^{-1}(J_u\mathrm{\Δ}u+J_p\mathrm{\Δ}p)=S_{xu}\mathrm{\Δ}u+S_{xp}\mathrm{\Δ}p---\left(6\right)$

In formulaFor sensitivity matrix；

For sensitivity matrix.

4. the wind energy turbine set Reactive-power control priority system of selection based on sensitivity according to claim 3, it is characterised in that In step 3, the Calculation of Sensitivity step bag that wind farm grid-connected point voltage is adjacent between wind energy turbine set output reactive power is obtained Include：

If J is the full rank Jacobian matrix of system polar form, Δ Y and Δ X is respectively system injection variable quantity and state becomes Change amount, is divided into two parts, i.e., by Δ Y：Δ Y=[Δ Y_IΔY_N]^T, corresponding Δ X is then changed into Δ X=[Δ X_IΔX_N]^T, correspondingly J is divided into into 4 parts, i.e.,：

$J=\left[\begin{array}{cc}{J}_{II}& J_{IN}\\ J_{NI}& J_{NN}\end{array}\right]---\left(7\right)$

J in formula (7)_II、J_IN、J_NI、J_NN--- the full rank Jacobian matrix in part,

Relation between injection rate and amount of state variation is

$\left[\begin{array}{c}\mathrm{\Δ}{Y}_I\\ {\mathrm{\ΔY}}_N\end{array}\right]=\left[\begin{array}{cc}{J}_{II}& J_{IN}\\ J_{NI}& J_{NN}\end{array}\right]\left[\begin{array}{c}\mathrm{\Δ}{X}_I\\ \mathrm{\Δ}{X}_N\end{array}\right]---\left(8\right)$

In formula (8),

ΔY_I--- controlled wind energy turbine set accesses the injection variable quantity of regional node；

ΔX_I--- controlled wind energy turbine set accesses the amount of state variation of regional node；

ΔY_N--- the injection variable quantity of remaining node；

ΔX_N--- the amount of state variation of remaining node,

If Δ Y_N=0, that is, the amount of being actually implanted into only include Δ Y_I, then can be released by formula (8)：

$\left\{\begin{array}{c}{\mathrm{\ΔY}}_I=J_{II}\·{\mathrm{\ΔX}}_I+J_{IN}\·{\mathrm{\ΔX}}_N\\ 0=J_{NI}\·{\mathrm{\ΔX}}_I+J_{NN}{\mathrm{\ΔX}}_N\end{array}\right.---\left(9\right)$

Due to J_NNIt is nonsingular so as to can obtain：

${\mathrm{\ΔY}}_I=(J_{II}-J_{IN}\·J_{NN}^{-1}\·J_{NI})\·{\mathrm{\ΔX}}_I=J_{SI}\·{\mathrm{\ΔX}}_I---\left(10\right)$

$J_{SI}=J_{II}-J_{IN}\·J_{NN}^{-1}\·J_{NI}---\left(11\right)$

To J_SIInvert：

Then the relation between the node of controlled wind energy turbine set access point area is

${\[{\mathrm{\Δ\θ}}_w,{\mathrm{\Δ\θ}}_c,{\mathrm{\ΔU}}_w,{\mathrm{\ΔU}}_c\]}^T=J_{SI}^{-1}{\[{\mathrm{\ΔP}}_W,{\mathrm{\ΔP}}_C,{\mathrm{\ΔQ}}_W,{\mathrm{\ΔQ}}_C\]}^T---\left(13\right)$

Δ U in formula_w--- the voltage of wind energy turbine set Egress node；

Δθ_w--- the phase angle change vector of wind energy turbine set Egress node；

ΔU_c--- the voltage of access point；

Δθ_c--- the phase angle change vector of access point；

ΔP_W--- wind energy turbine set Egress node injects active change vector；

ΔQ_W--- wind energy turbine set Egress node injects idle change vector；

ΔP_C--- access point injects active change vector；

ΔQ_C--- access point injects idle change vector,

Reactive power and the sensitivity relation of voltage, then can obtain the voltage of wind energy turbine set i with regard to wind energy turbine set j by formula (12) and formula (13) Output reactive power change sensitivity relation be

S₁=A_2m+n+i,m+n+j (14)

S in formula (14)₁--- the sensitivity that the voltage of wind energy turbine set i changes with regard to the output reactive power of wind energy turbine set j.

The voltage of wind energy turbine set j with regard to wind energy turbine set j output reactive power change sensitivity relation be

S₂=A_m+j,m+n+j (15)

S in formula (15)₂--- the sensitivity that the voltage of wind energy turbine set j changes with regard to the output reactive power of wind energy turbine set j.