Summary of the invention
The technical problem to be solved in the present invention provides a kind of wind energy turbine set AVC powerless control system and method that reduces the wind energy turbine set power loss, purpose is to make it take full advantage of the blower fan reactive power capability, realize the coordination control between wind energy turbine set reactive-load compensation equipment and the unit operation, and make the wind energy turbine set internal power proportion of goods damageds reduce to minimum degree.
The technical solution adopted in the present invention is:
Reduce the wind energy turbine set AVC powerless control system of wind energy turbine set power loss, comprising: wind energy turbine set AVC substation, wind-driven generator and reactive power compensator SVC; Tool originally is to be connected with wind-driven generator server, wind energy turbine set AGC, reactive power compensator SVC and scheduling station respectively by wind energy turbine set AVC substation.
Reduce the control method of the wind energy turbine set AVC powerless control system of wind energy turbine set power loss, comprise wind energy turbine set AVC substation, wind-driven generator and reactive power compensator SVC; Also comprise processor, memory module, input/output module, MODBUS (TCP/IP) communication interface, detection module, server; Processor is carried out control algolithm, and memory module and input/output module are called; Input/output module is communicated by letter with detection module by MODBUS (TCP/IP) communication interface, and communicates by the SCADA of server and wind turbine.
The information of the existing energy management platform of described wind energy turbine set AVC substation and wind energy turbine set exchange comprises state information and the control command of wind energy turbine set information, wind energy turbine set SVC equipment, comprises each blower fan real-time status information and control command with the information of blower fan server exchange; Wind energy turbine set AVC substation is idle or voltage-target directly is handed down to wind energy turbine set SVC, and SVC regulates and control by wind energy turbine set; The AVC substation system possesses communication, collection, control, calculating, storage, supervision, parameter function is set etc.; Wind-driven generator possesses idle fan-out capability, and blower fan SCADA can be controlled by the AVC system; Reactive power compensator is mainly SVC or SVG, and SVC and SVG all can be by issuing smooth adjustment idle or that the voltage instruction realization is idle to controller; The main transformer tap can be regulated high voltage bus voltage.
The wind energy turbine set AVC powerless control system of described reduction wind energy turbine set power loss, step is as follows:
The first step, AVC control system judge whether the voltage deviation value is out-of-limit, also site real-time voltage U
_{Mean}The point target voltage U of assigning with the control centre that is incorporated into the power networks
_{Target}Compare, obtain the voltage deviation value:
ΔU＝|U
_{mean}-U
_{target}| （1）；
In order to prevent the frequent adjusting of equipment, the voltage dead zone range is set, the scope of setting is Δ U≤0.01, wherein Δ U is
Amplitude; If voltage deviation value Δ U during greater than the threshold value of error dead band module, then carries out the idle of next step and adjusts;
In second step, at first survey the meritorious output valve P of current each blower fan
_{Gen}, the real-time maximum fan-out capability Q of the every typhoon machine of restriction relation of and idle output meritorious by blower fan
_{Reg (i)}=λ P
_{Gen (i)}, the idle reference value of wind-powered electricity generation unit of AVC default is total up to Q then
_{Wref}, namely blower fan total idle exert oneself given
Wherein the maximum idle constraints of blower fan is:
${P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}---\left(2\right);$
λ is the power factor of blower fan in the formula, and the power factor scope under the blower fan normal operation is λ
_{L}≤ λ≤λ
_{H}, by formula (2) as can be seen, when blower fan is completely sent out, will lose idle regulating power;
The limit computing formula of separate unit blower fan output reactive power is:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}\mathrm{max}}=\sqrt{\frac{{|U}_{1}|{X}_{m}^{2}}{{X}_{1}^{2}}{I}_{r\mathrm{max}}^{2}-{P}_{k}^{2}}-\frac{\left|{U}_{1}\right|}{{X}_{1}^{2}}\\ {Q}_{\mathrm{reg}\mathrm{min}}=\frac{\left|{U}_{1}\right|}{{X}_{1}^{2}}-\sqrt{\frac{{|U}_{1}|{X}_{m}^{2}}{{X}_{1}^{2}}{I}_{r\mathrm{max}}^{2}-{P}_{k}^{2}}\end{array}\right.---\left(3\right);$
U in the formula
_{1}Be blower fan stator terminal voltage, P
_{k}Be blower fan outlet active power, X
_{1}Be stator leakage reactance and excitation reactance sum, I
_{Rmax}Be the current transformer current limit value, be generally 1.5 times of current transformer rated current;
In the 3rd step, by voltage and idle relation, calculate the reactive power compensation amount:
ΔU＝ΔQ/S
_{sc} （4）；
S
_{sc}＝(U
_{now}-U
_{last})/(ΣQ
_{now}/U
_{now}-ΣQ
_{last}/U
_{last}) （5）；
In formula (4), (5), Δ Q is the reactive power variable quantity, S
_{Sc}Be the capacity of short circuit of system busbar side, Σ Q
_{Now}, Σ Q
_{Last}For last time total idle and current always idle, U
_{Last}, U
_{Now}Last time busbar voltage, current busbar voltage.If total reactive power demand Δ Q is greater than the overall idle fan-out capability Q of blower fan
_{Wref}, then entered for the 4th step; If Δ Q≤Q
_{Wref}, required idlely all sent out by blower fan then, at this moment, the idle set-point of separate unit blower fan is Q
_{Reg}(i)=Δ Q * Q
_{Reg (i)}/ Q
_{Wref}
If | Q
_{SVCmax}+ Q
_{Wref}|≤| Δ Q|, then the AVC system will provide the alarm prompt of regulating the main transformer tap;
The 4th step, wind energy turbine set inside causes the main air box change of power loss, current collection circuit, main transformer and concentrated reactive power compensator, and under certain wind speed, blower fan active power is fixed, in order to make the Power Output for Wind Power Field maximization, need make total active power loss minimum in the wind energy turbine set field, total-power loss:
${\mathrm{\ΔP}}_{\mathrm{\Σ}}(S,V)={P}_{0}\left(V\right)+{P}_{S}(S,V)+{P}_{\mathrm{LL}}(S,V)+{P}_{\mathrm{svc}}={\left(\frac{V}{{V}_{N}}\right)}^{2}\·{P}_{N0}+{\left(\frac{S}{{S}_{N}}\right)}^{2}\·\left(\frac{{V}_{N}}{V}\right)\·{P}_{\mathrm{NS}}+{\left(\frac{S}{{S}_{N}}\right)}^{2}\·\left(\frac{{V}_{N}}{V}\right)\·{P}_{\mathrm{NL}}+{P}_{\mathrm{svc}}---\left(6\right)$
Δ P in the formula
_{Σ}Be the total power loss of wind energy turbine set, P
_{0}Be transformer noload losses, P
_{S}Be transformer short-circuit loss, P
_{LL}Be line loss, V is transformer working voltage value, V
_{N}Be the transformer load voltage value, S is transformer operation apparent power value, S
_{N}Be the specified apparent power value of transformer, P
_{N0}Be the specified no-load loss of transformer, P
_{NS}Be the specified short circuit loss of transformer, P
_{NL}Be the loss of circuit rated power, P
_{Svc}Power loss for reactive power compensator;
Set wind energy turbine set total-power loss Δ P
_{Σ}Be target function, because all are connected in a plant capacity loss on the current collection circuit:
$P={I}^{2}R={({S}_{N}/\sqrt{3}{U}_{N})}^{2}R={({P}_{\mathrm{gen}}\×n/\mathrm{cos}\mathrm{\φ}/k/\sqrt{3}{U}_{N})}^{2}R---\left(7\right);$
Cos φ=λ wherein, n is the total platform number of blower fan, k is the percentage that actual electrical covers rated voltage;
The power loss P of reactive power compensator
_{Svc}Comprise the loss of reactor in the fixed loss of fixed capacitor group and the TCR branch road, in the practice, the loss of reactor changes with voltage, but change little, TCR type SVC for 10Mvar-50Mvar, its loss is about the 0.5%-0.7% of capacity, can be set at known quantity according to the wind energy turbine set actual conditions;
So wind energy turbine set total-power loss Δ P by formula (5)-(7) as can be known,
_{Σ}Only with the reactive power Q of each wind-driven generator
_{W}Relevant, formula (6) is converted to blower fan is idle to have the target function of distribution to be most:
T＝ΔP
_{Σ}(S,V)＝ΔP
_{Σ}(Q
_{gen}) （8）；
In the 5th step, to the target function T processing of minimizing, wind-force is sent out the reactive power value of machine when obtaining target function and having minimum value
The overall fan-out capability of wind-powered electricity generation unit is
And this process need be considered the constraints of reactive power equilibrium in the wind energy turbine set:
$\left\{\begin{array}{c}{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ {Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\end{array}\right.---\left(9\right);$
$\mathrm{\ΔQ}={Q}_{\mathrm{Wref}}^{*}+{Q}_{\mathrm{SVC}}-\mathrm{\Δ}{Q}_{\mathrm{\Σ}}---\left(10\right);$
Wherein:
Be the overall fan-out capability of wind energy turbine set wind-powered electricity generation unit;
Δ Q is the reactive power variable quantity, i.e. the scheduling value of the total reactive power of wind energy turbine set;
Δ Q
_{Σ}Be the total reactive loss of wind energy turbine set, can represent with blower fan is idle;
The 6th step is by to Q
_{Wref}With
Compare, if
The idle Q that is given as of blower fan then
_{Reg}, concentrate the idle Q that is given as of reactive power compensator
_{Svc}=Δ Q-Q
_{Wref}-Q
_{T}-Q
_{LL}If
Then blower fan is idle is given as
Concentrate that reactive power compensator is idle to be given as this moment
Q wherein
_{T}And Q
_{LL}Be respectively transformer and circuit reactive loss.
The control method of the wind energy turbine set AVC powerless control system of described reduction wind energy turbine set power loss, described step is as follows:
The first step is by the voltage U of real-time measurement and site
_{Mean}The point target voltage U of assigning with the control centre that is incorporated into the power networks
_{Target}Compare, with U
_{Mean}With U
_{Target}Compare, judge whether the voltage deviation value is out-of-limit,
ΔU＝|U
_{mean}-U
_{target}| （1）；
In order to prevent the frequent adjusting of equipment, the voltage dead zone range is set, the scope of setting is Δ U≤0.01, wherein Δ U is
Amplitude; , carries out voltage deviation value Δ U a moment set-point in the idle maintenance of wind energy turbine set if, then ending this secondary program less than the threshold value of dead band module; If voltage deviation value Δ U during greater than the threshold value of error dead band module, then carries out the idle of next step and adjusts;
In second step, calculate the real-time idle fan-out capability of blower fan:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}}=\mathrm{\λ}{P}_{\mathrm{gen}}\\ {Q}_{\mathrm{Wref}}={\mathrm{\Σ}}_{k=1}^{n}{Q}_{\mathrm{reg}}\end{array}\right.---\left(2\right);$
Q wherein
_{Reg}Constraints be:
$\left\{\begin{array}{c}{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ {Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\end{array}\right.---\left(3\right);$
In the 3rd step, calculate the reactive power compensation amount:
ΔU＝ΔQ/S
_{sc} （4）；
S
_{sc}＝(U
_{now}-U
_{last})/(ΣQ
_{now}/U
_{now}-ΣQ
_{last}/U
_{last}) （5）；
In the formula, Δ Q is S
_{Sc}Be the capacity of short circuit of system busbar side, Σ Q
_{Now}, Σ Q
_{Last}For last time total idle and current always idle, U
_{Last}, U
_{Now}Last time busbar voltage, current busbar voltage.If total reactive power demand Δ Q is greater than the overall idle fan-out capability Q of blower fan
_{Wref}, then entered for the 4th step; If Δ Q≤Q
_{Wref}, required idlely all sent out by blower fan then; If | Q
_{SVCmax}+ Q
_{Wref}|≤| Δ Q|, then the AVC system will provide the alarm prompt of regulating the main transformer tap;
In the 4th step, set up the target function between wind turbine generator reactive power and the wind energy turbine set loss:
T＝ΔP
_{Σ}(S,V)＝P
_{0}(V)+P
_{S}(S,V)+P
_{LL}(S,V)+P
_{svc}＝ΔP
_{Σ}(Q
_{gen}) （6）；
Constraints:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\\ {P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ \mathrm{\ΔQ}={Q}_{\mathrm{Wref}}^{*}+{Q}_{\mathrm{SVC}}-\mathrm{\Δ}{Q}_{\mathrm{\Σ}}\end{array}\right.---\left(7\right);$
Target function is asked local derviation, carry out minimization, total idle the exerting oneself of the blower fan of wind energy turbine set loss minimum during acquisition
The 5th step is by to Q
_{Wref}With
Compare, if
The idle Q that is given as of blower fan then
_{Reg}, concentrate the idle Q that is given as of reactive power compensator
_{Svc}=Δ Q-Q
_{Wref}-Q
_{T}-Q
_{LL}If
Then blower fan is idle is given as
Concentrate that reactive power compensator is idle to be given as this moment
Q wherein
_{T}And Q
_{LL}Be respectively transformer and circuit reactive loss;
In the 6th step, the AVC substation as control command, is sent to each wind-powered electricity generation unit and SVC with the reactive power setting value of wind turbine and concentrated reactive power compensator, finishes the idle control of wind energy turbine set.
Advantage of the present invention and good effect are as follows:
Control system of the present invention is foundation with wind energy turbine set power loss minimum, distribute the idle of every typhoon machine to exert oneself, satisfy under the prerequisite of electrical network requirement guaranteeing the control point, improved the generating efficiency of system, and guaranteed that every unit sends or the reactive power that absorbs in the allowed band of unit, guaranteed the safe operation of equipment.The present invention has brought into play the idle fan-out capability of blower fan to greatest extent owing to taken into full account the meritorious and idle relation of exerting oneself of blower fan, has reduced concentrated reactive power compensator switching frequency simultaneously, has improved it and has utilized benefit.
Embodiment
The present invention proposes the idle control strategy of wind energy turbine set AVC and is based on: in conjunction with the idle ability of exerting oneself of blower fan, control wind energy turbine set voltage control point (being that line port is sent in the transformer station high-pressure side) voltage in allowed limits, and make wind energy turbine set internal power loss minimum.
Basic ideas of the present invention are: wind energy turbine set AVC control system serves as the control target with wind energy turbine set high-voltage side bus voltage, take into account the blower fan set end voltage simultaneously in acceptable ranges, the idle fan-out capability of maximization blower fan reduces the SVC switching frequency, and maximization wind energy turbine set power loss.
As shown in fig. 1, wind energy turbine set AVC substation directly links to each other with scheduling station, wind energy turbine set AGC, blower fan supervisory control system and reactive power compensator SVC respectively, wind energy turbine set AVC substation and each several part exchange message are as shown in the figure, wherein wind energy turbine set AVC substation obtains each blower fan real-time status information from the blower fan supervisory control system, and carry out idle given calculating by wind energy turbine set AVC control unit, the result is that each power of fan factor is issued to blower fan by the blower fan supervisory control system again, realizes control on the spot; Wind energy turbine set AVC substation can be directly with Q in addition
_{Svc}Give wind energy turbine set SVC, SVC regulates and control by wind energy turbine set.
The set end voltage of the blower fan of all operations is all under the situation in acceptability limit in wind energy turbine set, after the scheduling controlling instruction is received in wind energy turbine set AVC substation, analyze by its COMPREHENSIVE CALCULATING, producing drift gage according to the control target calculates and reaches the needed total idle value of high-voltage side bus control desired value, then according to the present variable capacity of SVC/SVG, the variable capacity of whole classifications and the variable capacity of capacitor/reactor, coordinate control blower fan and concentrated reactive power compensator, follow the wind field high-voltage side bus voltage control instruction that scheduling station issues, the control time constant is about second-minute level.
As shown in Figure 2, a kind of wind energy turbine set AVC powerless control system that reduces the wind energy turbine set power loss comprises: AVC substation, wind power generation machine controller, reactive power compensator SVC, main transformer tap; Wind energy turbine set AVC substation is connected with blower fan server, wind energy turbine set AGC, wind energy turbine set SVC and scheduling station respectively, the information of the existing energy management platform of wind energy turbine set AVC substation and wind energy turbine set exchange comprises state information and the control command of wind energy turbine set information, SVC equipment, comprises each blower fan real-time status information and control command with the information of blower fan server exchange; Wind energy turbine set AVC substation is idle or voltage-target directly is handed down to wind energy turbine set SVC, and SVC regulates and control by wind energy turbine set.Wind energy turbine set SVC(Static Var Compensator)-and Static Var Compensator, can change idle that it sends fast, have stronger idle regulating power, can be electric power system the dynamic reactive power supply is provided.
Also comprise processor, memory module, input/output module, MODBUS (TCP/IP) communication interface, detection module, server; Processor is carried out control algolithm, and memory module and input/output module are called; Input/output module is communicated by letter with detection module by MODBUS (TCP/IP) communication interface, and communicates by the SCADA of server and wind turbine.
As shown in Figure 2, a kind of control method that reduces the wind energy turbine set AVC powerless control system of wind energy turbine set power loss as mentioned above, step is as follows:
The first step, AVC control system judge whether the voltage deviation value is out-of-limit, also site real-time voltage U
_{Mean}The point target voltage U of assigning with the control centre that is incorporated into the power networks
_{Target}Compare, obtain the voltage deviation value:
ΔU＝|U
_{mean}-U
_{target}| （1）
In order to prevent the frequent adjusting of equipment, the voltage dead zone range is set, the scope of setting is Δ U≤0.01, wherein Δ U is
Amplitude; If voltage deviation value Δ U during greater than the threshold value of error dead band module, then carries out the idle of next step and adjusts;
In the 3rd step, at first survey the meritorious output valve P of current each blower fan
_{Gen}, the real-time maximum fan-out capability Q of the every typhoon machine of restriction relation of and idle output meritorious by blower fan
_{Reg (i)}=λ P
_{Gen (i)}, the idle reference value of wind-powered electricity generation unit of AVC default is total up to Q then
_{Wref}, namely blower fan total idle exert oneself given
Wherein the maximum idle constraints of blower fan is:
${P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}---\left(2\right)$
λ is the power factor of blower fan in the formula, and the power factor scope under the blower fan normal operation is λ
_{L}≤ λ≤λ
_{H}, by formula (2) as can be seen, when blower fan is completely sent out, will lose idle regulating power.
The limit computing formula of separate unit blower fan output reactive power is:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}\mathrm{max}}=\sqrt{\frac{{|U}_{1}|{X}_{m}^{2}}{{X}_{1}^{2}}{I}_{r\mathrm{max}}^{2}-{P}_{k}^{2}}-\frac{\left|{U}_{1}\right|}{{X}_{1}^{2}}\\ {Q}_{\mathrm{reg}\mathrm{min}}=\frac{\left|{U}_{1}\right|}{{X}_{1}^{2}}-\sqrt{\frac{{|U}_{1}|{X}_{m}^{2}}{{X}_{1}^{2}}{I}_{r\mathrm{max}}^{2}-{P}_{k}^{2}}\end{array}\right.---\left(3\right)$
U in the formula
_{1}Be blower fan stator terminal voltage, P
_{k}Be blower fan outlet active power, X
_{1}Be stator leakage reactance and excitation reactance sum, I
_{Rmax}Be the current transformer current limit value, be generally 1.5 times of current transformer rated current
In second step, by voltage and idle relation, calculate the reactive power compensation amount:
ΔU＝ΔQ/S
_{sc} （4）
S
_{sc}＝(U
_{now}-U
_{last})/(ΣQ
_{now}/U
_{now}-ΣQ
_{last}/U
_{last}) （5）
In formula (4), (5), Δ Q is the reactive power variable quantity, S
_{Sc}Be the capacity of short circuit of system busbar side, Σ Q
_{Now}, Σ Q
_{Last}For last time total idle and current always idle, U
_{Last}, U
_{Now}Last time busbar voltage, current busbar voltage.If total reactive power demand Δ Q is greater than the overall idle fan-out capability Q of blower fan
_{Wref}, then entered for the 4th step; If Δ Q≤Q
_{Wref}, required idlely all sent out by blower fan then, at this moment, the idle set-point of separate unit blower fan is Q
_{Reg}(i)=Δ Q * Q
_{Reg (i)}/ Q
_{Wref}
If | Q
_{SVCmax}+ Q
_{Wref}|≤| Δ Q|, then the AVC system will provide the alarm prompt of regulating the main transformer tap.
The 4th step, wind energy turbine set inside causes the main air box change of power loss, current collection circuit, main transformer and concentrated reactive power compensator, and under certain wind speed, blower fan active power is fixed, in order to make the Power Output for Wind Power Field maximization, need make total active power loss minimum in the wind energy turbine set field, total-power loss:
${\mathrm{\ΔP}}_{\mathrm{\Σ}}(S,V)={P}_{0}\left(V\right)+{P}_{S}(S,V)+{P}_{\mathrm{LL}}(S,V)+{P}_{\mathrm{svc}}={\left(\frac{V}{{V}_{N}}\right)}^{2}\·{P}_{N0}+{\left(\frac{S}{{S}_{N}}\right)}^{2}\·\left(\frac{{V}_{N}}{V}\right)\·{P}_{\mathrm{NS}}+{\left(\frac{S}{{S}_{N}}\right)}^{2}\·\left(\frac{{V}_{N}}{V}\right)\·{P}_{\mathrm{NL}}+{P}_{\mathrm{svc}}---\left(6\right)$
Δ P in the formula
_{Σ}Be the total power loss of wind energy turbine set, P
_{0}Be transformer noload losses, P
_{S}Be transformer short-circuit loss, P
_{LL}Be line loss, V is transformer working voltage value, V
_{N}Be the transformer load voltage value, S is transformer operation apparent power value, S
_{N}Be the specified apparent power value of transformer, P
_{N0}Be the specified no-load loss of transformer, P
_{NS}Be the specified short circuit loss of transformer, P
_{NL}Be the loss of circuit rated power, P
_{Svc}Power loss for reactive power compensator.
Set wind energy turbine set total-power loss Δ P
_{Σ}Be target function, because all are connected in a plant capacity loss on the current collection circuit:
$P={I}^{2}R={({S}_{N}/\sqrt{3}{U}_{N})}^{2}R={({P}_{\mathrm{gen}}\×n/\mathrm{cos}\mathrm{\φ}/k/\sqrt{3}{U}_{N})}^{2}R---\left(7\right)$
Cos φ=λ wherein, n is the total platform number of blower fan, k is the percentage that actual electrical covers rated voltage.
The power loss P of reactive power compensator
_{Svc}Comprise the loss of reactor in the fixed loss of fixed capacitor group and the TCR branch road, in the practice, the loss of reactor changes with voltage, but change little, TCR type SVC for 10Mvar-50Mvar, its loss is about the 0.5%-0.7% of capacity, can be set at known quantity according to the wind energy turbine set actual conditions.
So wind energy turbine set total-power loss Δ P by formula (5)-(7) as can be known,
_{Σ}Only with the reactive power Q of each wind-driven generator
_{W}Relevant, formula (6) is converted to blower fan is idle to have the target function of distribution to be most:
T＝ΔP
_{Σ}(S,V)＝ΔP
_{Σ}(Q
_{gen}) （8）
In the 5th step, to the target function T processing of minimizing, wind-force is sent out the reactive power value of machine when obtaining target function and having minimum value
The overall fan-out capability of wind-powered electricity generation unit is
And this process need be considered the constraints of reactive power equilibrium in the wind energy turbine set:
$\left\{\begin{array}{c}{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ {Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\end{array}\right.---\left(9\right)$
$\mathrm{\ΔQ}={Q}_{\mathrm{Wref}}^{*}+{Q}_{\mathrm{SVC}}-\mathrm{\Δ}{Q}_{\mathrm{\Σ}}---\left(10\right)$
Wherein:
Be the overall fan-out capability of wind energy turbine set wind-powered electricity generation unit;
Δ Q is the reactive power variable quantity, i.e. the scheduling value of the total reactive power of wind energy turbine set;
Δ Q
_{Σ}Be the total reactive loss of wind energy turbine set, can represent with blower fan is idle;
The 6th step is by to Q
_{Wref}With
Compare, if
The idle Q that is given as of blower fan then
_{Reg}, concentrate the idle Q that is given as of reactive power compensator
_{Svc}=Δ Q-Q
_{Wref}-Q
_{T}-Q
_{LL}If
Then blower fan is idle is given as
Concentrate that reactive power compensator is idle to be given as this moment
Q wherein
_{T}And Q
_{LL}Be respectively transformer and circuit reactive loss.
Embodiment 1:
As shown in Figure 1, the idle given calculation process in wind energy turbine set AVC substation divides following steps:
The first step is by the voltage U of real-time measurement and site
_{Mean}The point target voltage U of assigning with the control centre that is incorporated into the power networks
_{Target}Compare, with U
_{Mean}With U
_{Target}Compare, judge whether the voltage deviation value is out-of-limit,
ΔU＝|U
_{mean}-U
_{target}| （1）；
In order to prevent the frequent adjusting of equipment, the voltage dead zone range is set, the scope of setting is Δ U≤0.01, wherein
Amplitude; , carries out voltage deviation value Δ U a moment set-point in the idle maintenance of wind energy turbine set if, then ending this secondary program less than the threshold value of dead band module; If voltage deviation value Δ U during greater than the threshold value of error dead band module, then carries out the idle of next step and adjusts.
In second step, calculate the real-time idle fan-out capability of blower fan:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}}=\mathrm{\λ}{P}_{\mathrm{gen}}\\ {Q}_{\mathrm{Wref}}={\mathrm{\Σ}}_{k=1}^{n}{Q}_{\mathrm{reg}}\end{array}\right.---\left(2\right);$
Q wherein
_{Reg}Constraints be:
$\left\{\begin{array}{c}{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ {Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\end{array}\right.---\left(3\right);$
In the 3rd step, calculate the reactive power compensation amount:
ΔU＝ΔQ/S
_{sc} （4）；
S
_{sc}＝(U
_{now}-U
_{last})/(ΣQ
_{now}/U
_{now}-ΣQ
_{last}/U
_{last}) （5）；
In the formula, Δ Q is S
_{Sc}Be the capacity of short circuit of system busbar side, Σ Q
_{Now}, Σ Q
_{Last}For last time total idle and current always idle, U
_{Last}, U
_{Now}Last time busbar voltage, current busbar voltage.If total reactive power demand Δ Q is greater than the overall idle fan-out capability Q of blower fan
_{Wref}, then entered for the 4th step; If Δ Q≤Q
_{Wref}, required idlely all sent out by blower fan then; If | Q
_{SVCmax}+ Q
_{Wref}|≤| Δ Q|, then the AVC system will provide the alarm prompt of regulating the main transformer tap.
In the 4th step, set up the target function between wind turbine generator reactive power and the wind energy turbine set loss:
T＝ΔP
_{Σ}(S,V)＝P
_{0}(V)+P
_{S}(S,V)+P
_{LL}(S,V)+P
_{svc}＝ΔP
_{Σ}(Q
_{gen}) （6）；
Constraints:
$\left\{\begin{array}{c}{Q}_{\mathrm{reg}\mathrm{min}}\≤{Q}_{\mathrm{reg}}\≤{Q}_{\mathrm{reg}\mathrm{max}}\\ {P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{L}^{2}}}{{\mathrm{\λ}}_{L}}\≤{Q}_{\mathrm{reg}}\≤{P}_{W}\frac{\sqrt{1-{\mathrm{\λ}}_{H}^{2}}}{{\mathrm{\λ}}_{H}}\\ \mathrm{\ΔQ}={Q}_{\mathrm{Wref}}^{*}+{Q}_{\mathrm{SVC}}-\mathrm{\Δ}{Q}_{\mathrm{\Σ}}\end{array}\right.---\left(7\right);$
Target function is asked local derviation, carry out minimization, total idle the exerting oneself of the blower fan of wind energy turbine set loss minimum during acquisition
The 5th step is by to Q
_{Wref}With
Compare, if
The idle Q that is given as of blower fan then
_{Reg}, concentrate the idle Q that is given as of reactive power compensator
_{Svc}=Δ Q-Q
_{Wref}-Q
_{T}-Q
_{LL}If
Then blower fan is idle is given as
Concentrate that reactive power compensator is idle to be given as this moment
Q wherein
_{T}And Q
_{LL}Be respectively transformer and circuit reactive loss.
In the 6th step, the AVC substation as control command, is sent to each wind-powered electricity generation unit and SVC with the reactive power setting value of wind turbine and concentrated reactive power compensator, finishes the idle control of wind energy turbine set.
This control module can realize that data handle, and the idle link of adjusting comprises that PI utilizes the voltage deviation value to calculate no-power vacancy, calculates the maximum output constraint of reactive power, the idle reference value Δ Q of gained is obtained the idle setting value Q of wind energy turbine set through the maximum idle output constraint of wind energy turbine set relatively after retraining with the wind energy turbine set power factor when regulating
_{Reg}No distribution of work link comprises that the loss of calculated field inner blower and the minimum idle size of exerting oneself of every typhoon machine namely utilize idle setting value to distribute according to the allocation strategy that the present invention proposes.