A wind farm power generation capacity dynamic evaluation method and system

Abstract

The application discloses a kind of wind farm power generation capacity dynamic evaluation method and system, the wind farm power generation capacity dynamic evaluation method, according to historical data, the wind speed of next time is predicted;Current time MPPT power is calculated, and compared with current time actual power, and the load reduction rate is calculated;According to the wind speed predicted, the MPPT power of next time wind turbine unit is calculated, and the predicted power of next time is calculated by multiplying load reduction rate;According to the wind speed predicted, the maximum mechanical power of next time is calculated, and by comparing with the predicted power of next time, the speed prediction value of next time, pitch angle prediction value is calculated;Solving wind turbine unit single machine regulating process differential equation, obtain the trial power generation power, and the active adjustable upper limit and lower limit of the wind turbine unit are obtained;According to the size of the wind turbine unit terminal voltage, the reactive power adjustable upper limit and lower limit of the wind turbine unit are calculated;Active power generation capacity of wind farm is calculated;Field station reactive power correction coefficient is calculated, and the reactive power generation capacity of the wind farm is calculated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy power generation capacity dynamic evaluation, in particular to a wind farm power generation capacity dynamic evaluation method and system. BACKGROUND

[0002] In the power system, wind farms as an important form of new energy power generation, its output is affected by weather conditions, equipment performance and other factors, showing significant intermittency and volatility. In the process of power dispatching, automatic generation control (AGC) and automatic voltage control (AVC) have become the key means to maintain the stable operation of the system. However, due to the output characteristics of wind power, its AGC / AVC regulation capacity is not infinite, but there is a certain limit. The output limit of the wind farm is subject to its physical characteristics, for example, the output of the wind turbine is limited by wind speed, wind wheel diameter and generator efficiency and other factors. These physical characteristics determine the maximum and minimum output limits of the wind farm, limiting its output adjustment range in the AGC / AVC regulation process. The safe and stable operation of the power system also requires the AGC / AVC regulation limit of the wind farm. In the process of power system operation, it is necessary to maintain a certain frequency and voltage stability margin to ensure the normal operation of the system. Therefore, when designing the AGC / AVC regulation strategy of the wind farm, the safety constraints and stability requirements of the system must be considered to avoid excessive regulation leading to system instability. With the large-scale grid-connected operation of renewable energy, the output fluctuation of the wind farm has a significant impact on the power system. In order to cope with such fluctuations, reasonable AGC / AVC regulation limits need to be established to balance the access of renewable energy and the stable operation of the power system. SUMMARY

[0003] The present application aims to provide a wind farm power generation capacity dynamic evaluation method that can evaluate the upper and lower limits of the active and reactive power generation capacity of the wind farm to ensure the stability and reliability of the AGC / AVC regulation process of the power grid. Another object of the present application is to provide a wind farm power generation capacity dynamic evaluation system.

[0004] Technical scheme: The wind farm power generation capacity dynamic evaluation method of the present application comprises the following steps:

[0005] (1) Obtain the current time t-0 minute history sampling data v(t-0)~v(t-f+1) of the wind turbine of the wind farm;

[0006] (2) Predict the wind speed v(t+1) at the next time, respectively determine the active power of the wind turbine MPPT corresponding to the wind speed at t-0 and t+1; calculate the load reduction rate μ according to the active power P MPPT(t-0) and the actual active power P (t-0) of the wind turbine MPPT at t-0.

[0007] (3) Based on the active power P of the wind turbine generator set MPPT at time t+1 MPPT(t+1) Calculate the predicted active power at time t+1 using the load reduction rate μ in step (2); if P (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, calculate the propeller pitch angle β at time t+1. (t+1) If P (t+1) Greater than P m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, calculate the fan speed ω at time t+1. (t+1) ;

[0008] (4) Repeat steps (2)-(3) to obtain the predicted values ​​of wind speed, wind turbine speed, pitch angle and active power of wind turbine generator MPPT at future times t+1 to t+g;

[0009] (5) Based on the predicted values ​​of wind speed, turbine speed, pitch angle, and active power of the wind turbine generator set at times t+1 to t+g obtained in step (4), construct a single-unit regulation model of the wind turbine generator set, and use the bisection method to solve for the state variable Ω(t=T end )=Ω set The test increase in power P at that time over And the current active power up-regulation capacity P of wind turbines up and the ability to reduce P down ;

[0010] (6) Determine the reactive power up-regulation capability Q of a single wind turbine generator unit based on the current terminal voltage U of the wind turbine generator unit. up And the ability to reduce reactive power Q down ;

[0011] (7) Calculate the active power up-regulation capacity P of the wind farm at the site level. up The ability to reduce P is positive. down and reactive power regulation capability correction term ΔQ l According to the grid connection voltage U of the wind farm pcc Determine the reactive power upscaling capacity Q of the wind farm at the site level. up And the ability to reduce reactive power Q down .

[0012] Furthermore, taking f = 30, the wind speed v(t+1) at the next moment is:

[0013] v(t+1)=a0×1.0+a1×v(t-0)+a2×v(t-1)+L+a 30 ×v(t-29) (1)

[0014] wherein a0-a 30 are coefficients.

[0015] Further, the wind turbine MPPT active power, the wind turbine speed and the pitch angle at the time t-0 and t+1 corresponding to the wind turbine MPPT state are determined, which are as follows:

[0016] If the current wind speed v < 4 m / s or v > 20 m / s, then the wind turbine MPPT wind turbine speed ω MPPT = 0, the active power P MPPT = 0, and the pitch angle β MPPT = 90.

[0017] If the current wind speed v > 4 m / s and v < 12 m / s, then the wind turbine MPPT pitch angle β MPPT = 0, the wind turbine speed ω MPPT and the active power P MPPT are the wind turbine speed ω and the mechanical power P m maximum when the pitch angle β = 0 and the wind turbine speed ω is in the interval [0.7, 1.25]. m

[0018]

[0019] wherein c1-c8 are fitting parameter constants; K m is a mechanical power coefficient constant; and R is the impeller radius.

[0020] If the current wind speed v > 12 m / s and v < 20 m / s, then the wind turbine MPPT wind turbine speed ω MPPT = 1.25, the active power P MPPT = 1.0, and the pitch angle β MPPT is the pitch angle β when the wind turbine speed ω = 1.25 and the mechanical power P m = 1.0.

[0021] Further, according to the active power P MPPT(t-0) and the actual active power P (t-0) at the time t-0 corresponding to the wind turbine MPPT state, the load reduction rate μ is

[0022]

[0023] Further, the active power prediction value P (t+1) at the time t+1 is obtained by multiplying P MPPT(t+1) by the load reduction rate μ.

[0024] ​Further, the single-machine regulation model of the wind turbine generator unit is

[0025]

[0026] The initial state of the state variable is

[0027]

[0028] wherein J WTG is the rotational inertia of the wind turbine; T end is the support end time; λ β is a constant, Ω(t) is the state variable, 0≤t≤T end , P m is the mechanical power, P over is the trial power increase, and β MPPT is the MPPT pitch angle.

[0029] Further, when the trial power increase P over is in the range 0≤P over ≤1, the active power up-regulation capability P up and the active power down-regulation capability P down of the wind turbine generator unit are calculated according to the trial power increase P over when the state variable Ω(t=T end ) = Ω set ;

[0030]

[0031] wherein S is the rated capacity of the calculation unit; Ω set is the set minimum rotational speed of the wind turbine; P is the current active power of the wind turbine generator unit; and Q is the current reactive power of the wind turbine generator unit.

[0032] Further, according to the current single-machine terminal voltage U of the wind turbine generator unit, the reactive power up-regulation capability Q up and the reactive power down-regulation capability Q down of the wind turbine generator unit are determined as follows:

[0033] If the current single-machine terminal voltage U of the wind turbine generator unit is U≥0 and U<0.9, the reactive power up-regulation capability Q up and the reactive power down-regulation capability Q down of the wind turbine generator unit are

[0034]

[0035] wherein K1 is a coefficient.

[0036] If the current single-machine terminal voltage U of the wind turbine generator unit is U≥0.9 and U≤1.3, the reactive power up-regulation capability Q upand reactive down-regulation capability Q down For

[0037]

[0038] wherein P is the current active power of the wind turbine, and S is the rated capacity of the calculation unit.

[0039] Further, the station-level active up-regulation capability P up and the active down-regulation capability P down of the wind farm are

[0040]

[0041] wherein P WTGup and P WTGdown represent the active up-regulation capability P up and the active down-regulation capability P down of the respective wind turbine generator unit in the wind farm, respectively.

[0042] The reactive regulation capability correction term AQ l is

[0043]

[0044] wherein P is the active power of the respective wind turbine in the wind farm, Q is the reactive power of the respective wind turbine in the wind farm, and X eq is a coefficient, and U PCC is the voltage at the point of interconnection of the wind farm.

[0045] If the voltage U pcc at the point of interconnection of the wind farm is ≥ 0 and U pcc < 0.9, then the station-level reactive up-regulation capability Q up and the reactive down-regulation capability Q down of the wind farm are

[0046]

[0047] wherein K1 is a coefficient, and U WTG is the voltage at the terminal of the respective wind turbine.

[0048] If the voltage U pcc at the point of interconnection of the wind farm is ≥ 0.9 and U pcc ≤ 1.3, then the station-level reactive up-regulation capability Q up and the reactive down-regulation capability Q down of the wind farm are

[0049]

[0050] wherein P WTG is the active power of the respective wind turbine, U WTG is the voltage at the terminal of the respective wind turbine, and SWTG This is the ratio of the actual rated capacity to the actual rated power of each wind turbine unit.

[0051] The wind farm power generation capacity dynamic evaluation system of the present invention includes

[0052] The data sampling module is used to acquire historical sampling data v(t-0)~v(t-f+1) of the wind turbine generators in the wind farm at the current time t, f minutes before the current time.

[0053] The calculation module is used to predict the wind speed v(t+1) at the next moment, and to determine the active power of the wind turbine generator set at the MPPT corresponding to the wind speed at t-0 and t+1, respectively; based on the active power P of the wind turbine generator set at the MPPT state at t-0... MPPT(t-0) and actual active power P (t-0) Calculate the load factor μ; based on the active power P of the wind turbine generator's MPPT at time t+1. MPPT(t+1) Given the load shedding rate μ, calculate the predicted active power at time t+1; if P (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, calculate the propeller pitch angle β at time t+1. (t+1) If P (t+1) Greater than P m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, calculate the fan speed ω at time t+1. (t+1) ; Obtain the predicted values ​​of wind speed, turbine speed, pitch angle, and active power of the wind turbine generator set at times t+1 to t+g in the future;

[0054] The model building module is used to build a single-unit regulation model of the wind turbine generator based on the wind speed, turbine speed, pitch angle and active power prediction values ​​of the wind turbine generator's MPPT at future times t+1 to t+g.

[0055] The dynamic capability solving module is used to solve for the state variable Ω (t = T) using the bisection method. end )=Ω set The test increase in power P at that time over And the current active power up-regulation capacity P of wind turbines up and the ability to reduce P down Based on the current terminal voltage U of the wind turbine generator set, determine the reactive power up-regulation capability Q of the wind turbine generator set. up And the ability to reduce reactive power Q down ; Calculate the active power up-regulation capacity P of the wind farm at the site level up The ability to reduce P is positive. down and reactive power regulation capability correction term ΔQ l According to the grid connection voltage U of the wind farmpcc Determine the reactive power upscaling capacity Q of the wind farm at the site level. up And the ability to reduce reactive power Q down .

[0056] Beneficial effects: Compared with the prior art, the significant advantages of this invention are: This invention predicts the wind speed, pitch angle, rotational speed and active power of each wind turbine in the next 16 minutes by using historical data from the previous 30 minutes. Based on this, it calculates the adjustable upper and lower limits of active power and reactive power of each wind turbine in the next 16 minutes, and finally predicts the power generation capacity of the entire wind farm in the next 16 minutes. This further improves the perception capability of the AGC / AVC regulation system and ensures the rationality and reliability of AGC / AVC regulation. Attached Figure Description

[0057] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0058] The invention will now be further described with reference to the accompanying drawings.

[0059] The dynamic evaluation method for wind farm power generation capacity described in this invention includes the following steps:

[0060] 1) Obtain the historical sampling data v(t-0)~v(t-29) of the wind turbine unit 30 minutes before the current moment, and predict the wind speed v(t+1) at the next moment.

[0061] 2) Calculate the MPPT state of the wind turbine unit corresponding to the wind speed v(t-0) at time t-0, including the MPPT power P. MPPT(t-0) MPPT rotational speed ω MPPT(t-0) MPPT pitch angle β MPPT(t-0) .

[0062] 3) Based on the active power P of the fan under MPPT state at time t-0 MPPT(t-0) and actual active power P (t-0) Calculate the load reduction rate μ.

[0063] 4) Based on the wind speed v(t+1) obtained in 1), calculate the active power P under MPPT state at time t+1. MPPT(t+1) The active power P under MPPT state at time t+1 MPPT(t+1) Multiply by the load reduction rate μ in 3) to calculate the predicted active power P at time t+1. (t+1) .

[0064] 5) Calculate the mechanical power P of the wind turbine at time t+1 under the following conditions: wind speed ω = 1.25, blade pitch angle β = 0, and wind speed v(t+1). m(t+1) .

[0065] If the predicted active power value P at time t+1 (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, active power P (t+1) Calculate the wind speed v(t+1) and the propeller pitch angle β at time t+1. (t+1) .

[0066] If the predicted active power value P at time t+1 (t+1) The mechanical power P of the wind turbine at time t+1 is greater than m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, active power P (t+1) Given the wind speed v(t+1), calculate the fan speed ω at time t+1. (t+1) .

[0067] 6) Take the predicted wind speed at time t+1 as the historical wind speed at time t+2, and repeat steps 1) to 5) above to obtain the predicted values ​​of wind speed v, turbine speed ω, blade pitch angle β, and active power P at times t+1 to t+16 in the future, for a total of 16 sets.

[0068] 7) Test the increase in power P over In the range 0≤P over In the case of ≤1, find the solution that makes the state variable Ω(t=T) end )=Ω set The test increase in power P at that time over Under this condition, the active power adjustment capacity P of the wind turbine is... up And the ability to reduce P down They are respectively:

[0069]

[0070] Where S is the rated capacity of the computing unit; Ω set P is the set minimum speed of the fan, P is the current active power of the fan, and Q is the current reactive power of the fan.

[0071] 8) If the fan terminal voltage U≥0 and U<0.9, then the reactive power adjustment capability Q of the fan in this state is... up And the ability to reduce reactive power Q down They are respectively:

[0072]

[0073] Where K1 is a coefficient.

[0074] If the turbine terminal voltage U ≥ 0.9 and U ≤ 1.3, then the reactive power up-adjustment capacity Q of the turbine under this condition is... up And the ability to reduce reactive power Qdown respectively.

[0075]

[0076] where P is the current active power of the wind turbine, and S is the rated capacity of the calculation unit.

[0077] 9) Calculate the station-level active power up-regulation capability P of the evaluated wind farm up and the station-level active power down-regulation capability P down .

[0078]

[0079] where P WTGup and P WTGdown are the active power up-regulation capability P up and the active power down-regulation capability P down of each wind turbine in the wind farm, respectively.

[0080] 10) Calculate the station-level reactive power regulation capability correction term AQ of the evaluated wind farm l .

[0081]

[0082] where P is the active power of each wind turbine in the wind farm, Q is the reactive power of each wind turbine in the wind farm, X eq is a coefficient, and U PCC is the grid-connection point voltage of the wind farm.

[0083] 11) If the grid-connection point voltage U pcc ≥ 0 and U pcc < 0.9, then the station-level reactive power up-regulation capability Q up and the station-level reactive power down-regulation capability Q down of the wind farm in this state are respectively:

[0084]

[0085] where K1 is a coefficient, and U WTG is the terminal voltage of each wind turbine unit.

[0086] If the grid-connection point voltage U pcc ≥ 0.9 and U pcc ≤ 1.3, then the station-level reactive power up-regulation capability Q up and the station-level reactive power down-regulation capability Q down of the wind farm in this state are respectively:

[0087]

[0088] where P WTG is the active power of each wind turbine unit, and UWTG S represents the terminal voltage of each wind turbine unit. WTG This is the ratio of the actual rated capacity to the actual rated power of each wind turbine unit.

[0089] The wind farm power generation capacity dynamic evaluation system of the present invention includes

[0090] The data sampling module is used to acquire historical sampling data v(t-0)~v(t-f+1) of the wind turbine generators in the wind farm at the current time t, f minutes before the current time.

[0091] The calculation module is used to predict the wind speed v(t+1) at the next moment, and to determine the active power of the wind turbine generator set at the MPPT corresponding to the wind speed at t-0 and t+1, respectively; based on the active power P of the wind turbine generator set at the MPPT state at t-0... MPPT(t-0) and actual active power P (t-0) Calculate the load factor μ; based on the active power P of the wind turbine generator's MPPT at time t+1. MPPT(t+1) Given the load shedding rate μ, calculate the predicted active power at time t+1; if P (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, calculate the propeller pitch angle β at time t+1. (t+1) If P (t+1) Greater than P m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, calculate the fan speed ω at time t+1. (t+1) ; Obtain the predicted values ​​of wind speed, turbine speed, pitch angle, and active power of the wind turbine generator set at times t+1 to t+g in the future;

[0092] The model building module is used to build a single-unit regulation model of the wind turbine generator based on the wind speed, turbine speed, pitch angle and active power prediction values ​​of the wind turbine generator's MPPT at future times t+1 to t+g.

[0093] The dynamic capability solving module is used to solve for the state variable Ω (t = T) using the bisection method. end )=Ω set The test increase in power P at that time over And the current active power up-regulation capacity P of wind turbines up and the ability to reduce P down Based on the current terminal voltage U of the wind turbine generator set, determine the reactive power up-regulation capability Q of the wind turbine generator set. up And the ability to reduce reactive power Q down ; Calculate the active power up-regulation capacity P of the wind farm at the site level up The ability to reduce P is positive. down and reactive power regulation capability correction term ΔQl ; determining the field station level reactive power up-regulation capability Q of the wind farm according to the wind farm point of common coupling voltage Upcc up and the reactive power down-regulation capability Q down .

[0094] Those skilled in the art will understand that embodiments of the present application can be provided as methods, systems, or computer program products. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code thereon. Embodiments of the present application can be implemented in various computer languages, including, for example, the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0095] The present application is described in reference to the flow diagrams and / or block diagrams of the methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flow diagrams and / or block diagrams, and combinations of blocks in the flow diagrams and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing device or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 one or more flow or flow processes and / or blocks Figure 1 means for carrying out the function specified by the flow or flow processes and / or block or blocks.

[0096] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions means which implement the function specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 one or more flow or flow processes and / or blocks Figure 1 means for carrying out the function specified by the flow or flow processes and / or block or blocks.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 one or more flow or flow processes and / or blocks Figure 1 means for carrying out the function specified by the flow or flow processes and / or block or blocks.

Claims

1. A method for dynamically evaluating the power generation capacity of a wind farm, characterized in that, Includes the following steps: (1) Obtain historical sampling data v(t-0)~v(t-f+1) of the wind turbine generator set at the wind farm at the current time t, f minutes before the current time; (2) Predict the wind speed v(t+1) at the next moment. Determine the wind turbines with the corresponding wind speeds at t-0 and t+1 respectively. The active power of the wind turbine generator set under MPPT conditions at time t-0; based on the active power P of the wind turbine generator set under MPPT conditions. MPPT(t-0) and actual active power P (t-0) Calculate the load reduction rate μ; (3) Based on the active power P of the wind turbine generator set MPPT at time t+1 MPPT(t+1) Calculate the predicted active power at time t+1 using the load reduction rate μ in step (2); if P (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, calculate the propeller pitch angle β at time t+1. (t+1) If P (t+1) Greater than P m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, calculate the fan speed ω at time t+1. (t+1) ; (4) Repeat steps (2)-(3) to obtain the predicted values ​​of wind speed, wind turbine speed, pitch angle and active power of wind turbine generator MPPT at future times t+1 to t+g; (5) Based on the predicted values ​​of wind speed, turbine speed, pitch angle, and active power of the wind turbine generator set at times t+1 to t+g obtained in step (4), construct a single-unit regulation model of the wind turbine generator set, and use the bisection method to solve for the state variable Ω(t=T end )=Ω set The test increase in power P at that time over And the current active power up-regulation capacity P of wind turbines up and the ability to reduce P down ; (6) Determine the reactive power up-regulation capability Q of a single wind turbine generator unit based on the current terminal voltage U of the wind turbine generator unit. up And the ability to reduce reactive power Q down ; (7) Calculate the active power up-regulation capacity P of the wind farm at the site level. up The ability to reduce P is positive. down and reactive power regulation capability correction term ΔQ l According to the grid connection voltage U of the wind farm pcc Determine the reactive power upscaling capacity Q of the wind farm at the site level. up And the ability to reduce reactive power Q down .

2. The method for dynamic evaluation of wind farm power generation capacity according to claim 1, characterized in that, Let f = 30, then the wind speed at the next moment v(t+1) is: v(t+1)=a0×1.0+a1×v(t-0)+a2×v(t-1)+L+a 30 ×v(t-29) (1) Where a0~a 30 is a coefficient.

3. The method for dynamic evaluation of wind farm power generation capacity according to claim 2, characterized in that, The MPPT active power, turbine speed, and pitch angle of the wind turbine generator at times t-0 and t+1 are determined as follows: If the current wind speed v < 4 m / s or v > 20 m / s, then the MPPT wind turbine speed ω of the wind turbine unit at that moment is... MPPT =0, active power P MPPT =0, pitch angle β MPPT =90; If the wind speed at the current moment is v > 4 m / s and v < 12 m / s, then the MPPT pitch angle β of the wind turbine at that moment is... MPPT =0, fan speed ω MPPT and active power P MPPT Let P be the mechanical power when the pitch angle β = 0 and the turbine speed ω is in the interval [0.7, 1.25]. m The maximum fan speed ω and mechanical power P m Maximum value; Where c1 to c8 are constant fitting parameters; K m R is the mechanical power coefficient constant; R is the impeller radius; If the current wind speed v > 12 m / s and v < 20 m / s, then the MPPT wind turbine speed ω of the wind turbine generator set at that moment is... MPPT =1.25, active power P MPPT =1.0, pitch angle β MPPT For the fan speed ω=1.25 and the mechanical power P m The pitch angle β when = 1.

0.

4. The method for dynamic evaluation of wind farm power generation capacity according to claim 3, characterized in that, Based on the active power P of the wind turbine generator under MPPT state at time t-0 MPPT(t-0) and actual active power P (t-0) The load reduction rate μ is 5. The method for dynamic evaluation of wind farm power generation capacity according to claim 4, characterized in that, Predicted active power P at time t+1 (t+1) By P MPPT(t+1) It is obtained by multiplying by the load reduction rate μ.

6. The method for dynamic evaluation of wind farm power generation capacity according to claim 5, characterized in that, The single-unit regulation model of wind turbine generator is The initial state of the state variable is Ω(t=0)=ω (5) Among them, J WTG T is the moment of inertia of the fan. end Support end time; λ β Let Ω(t) be a constant, and 0 ≤ t ≤ T be a state variable. end P m For mechanical power, P over To test the increased power output, β MPPT This is the MPPT pitch angle.

7. The method for dynamic evaluation of wind farm power generation capacity according to claim 6, characterized in that, When testing the increased power P over In the range 0≤P over ≤1, according to the state variable Ω(t=T) end )=Ω set The test increase in power P at that time over Calculate the active power up-regulation capacity P of the wind turbine generator set. up And the ability to reduce P down ; Where S is the rated capacity of the computing unit, Ω set P is the minimum speed of the wind turbine, Q is the current active power of the wind turbine generator set, and Q is the current reactive power of the wind turbine generator set.

8. The method for dynamic evaluation of wind farm power generation capacity according to claim 7, characterized in that, Based on the current terminal voltage U of the wind turbine generator set, determine the reactive power up-regulation capacity Q of the wind turbine generator set. up And the ability to reduce reactive power Q down Specifically as follows: If the current single-unit terminal voltage of the wind turbine generator is U≥0 and U<0.9, then the reactive power up-regulation capability Q of the single-unit wind turbine generator is... up And the ability to reduce reactive power Q down for Where K1 is the coefficient; If the current single-unit terminal voltage of the wind turbine generator is U≥0.9 and U≤1.3, then the reactive power up-regulation capability Q of the single-unit wind turbine generator is... up And the ability to reduce reactive power Q down for Where P is the current active power of the wind turbine, and S is the rated capacity of the calculation unit.

9. The method for dynamic evaluation of wind farm power generation capacity according to claim 8, characterized in that, The active power up-regulation capacity P of wind farms at the site level up And the ability to reduce P down for Among them, P WTGup and P WTGdown P represents the active power up-regulation capacity P of each wind turbine generator in the wind farm. up And the ability to reduce P down ; Reactive power regulation capability correction term ΔQ l for Where P represents the active power of each wind turbine in the wind farm, Q represents the reactive power of each wind turbine in the wind farm, and X... eq U is a coefficient. PCC This refers to the voltage at the wind farm's grid connection point. If the grid connection voltage of the wind farm is U pcc ≥0 and U pcc If the value is less than 0.9, then the reactive power up-regulation capacity Q of the wind farm at the site level is... up And the ability to reduce reactive power Q down for Where K1 is the coefficient, U WTG This refers to the terminal voltage of each wind turbine unit; If the grid connection voltage of the wind farm is U pcc ≥0.9 and U pcc If the reactive power up-regulation capacity Q of the wind farm is ≤1.3, then... up And the ability to reduce reactive power Q down for Among them, P WTG For the active power of each wind turbine unit, U WTG S represents the terminal voltage of each wind turbine unit. WTG This is the ratio of the actual rated capacity to the actual rated power of each wind turbine unit.

10. A dynamic evaluation system for the power generation capacity of a wind farm, characterized in that, include The data sampling module is used to acquire historical sampling data v(t-0)~v(t-f+1) of the wind turbine generators in the wind farm at the current time t, f minutes before the current time. The calculation module is used to predict the wind speed v(t+1) at the next moment, and to determine the active power of the wind turbine generator set at the MPPT corresponding to the wind speed at t-0 and t+1, respectively; based on the active power P of the wind turbine generator set at the MPPT state at t-0... MPPT(t-0) and actual active power P (t-0) Calculate the load reduction rate μ; Based on the active power P of the wind turbine generator's MPPT at time t+1 MPPT(t+1) Given the load shedding rate μ, calculate the predicted active power at time t+1; if P (t+1) The mechanical power P of the wind turbine at time t+1 is less than or equal to that at time t+1. m(t+1) Then the fan speed ω at time t+1 (t+1) =1.25, calculate the propeller pitch angle β at time t+1. (t+1) If P (t+1) Greater than P m(t+1) Then the propeller pitch angle β at time t+1 (t+1) =0, calculate the fan speed ω at time t+1. (t+1) ; Obtain the predicted values ​​of wind speed, turbine speed, pitch angle, and active power of the wind turbine generator set at times t+1 to t+g in the future; The model building module is used to build a single-unit regulation model of the wind turbine generator based on the wind speed, turbine speed, pitch angle and active power prediction values ​​of the wind turbine generator's MPPT at future times t+1 to t+g. The dynamic capability solving module is used to solve for the state variable Ω (t = T) using the bisection method. end )=Ω set The test increase in power P at that time over And the current active power up-regulation capacity P of wind turbines up and the ability to reduce P down Based on the current terminal voltage U of the wind turbine generator set, determine the reactive power up-regulation capability Q of the wind turbine generator set. up And the ability to reduce reactive power Q down ; Calculate the active power up-regulation capacity P of the wind farm at the site level up The ability to reduce P is positive. down and reactive power regulation capability correction term ΔQ l According to the grid connection voltage U of the wind farm pcc Determine the reactive power upscaling capacity Q of the wind farm at the site level. up And the ability to reduce reactive power Q down .

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