Power-optimized resonance ride-through control method and system for wind turbine generators

Abstract

The application discloses a wind turbine resonance crossing control method and system based on power optimization. First, the average wind speed and the average pitch angle of the current external wind turbine are obtained, the tip speed ratio of the wind turbine running on the upper and lower boundaries of the speed forbidden zone under the average wind speed is calculated, then the wind energy utilization coefficient corresponding to the tip speed ratio of the speed forbidden zone upper and lower boundaries under the average pitch angle is obtained by table lookup, the difference of the wind energy utilization coefficient when running on the upper and lower boundaries under the average wind speed is calculated, when the wind energy utilization coefficient of the wind turbine running on the upper boundary of the speed forbidden zone is larger and itself is maintained on the lower boundary of the forbidden zone, the wind turbine up-crossing is triggered, when the wind energy utilization coefficient of the wind turbine running on the lower boundary of the speed forbidden zone is larger and itself is maintained on the upper boundary of the lower forbidden zone, the wind turbine down-crossing is triggered, thereby optimizing the power generation of the wind turbine in the resonance interval wind speed section.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, in particular to a wind turbine resonance crossing control method and system based on power optimization, a storage medium and a computing device. BACKGROUND

[0002] For many wind turbines, when the frequency of the blade sweeping across the tower is close to the natural frequency of the tower itself, there is a risk of resonance, which will seriously threaten the safety of the unit. We also call this operating speed of the unit as the resonance speed.

[0003] Currently, there are two common methods to avoid the resonance of the unit: one is to set the cut-in speed of the unit above the resonance speed; the other is to draw a speed forbidden zone near the resonance speed, maintain the speed outside the speed forbidden zone through torque control, and complete the rapid passing of the speed on both sides of the forbidden zone through the judgment of the external wind conditions, which is commonly known as the resonance crossing strategy, as shown in FIG. 1. Resonance crossing is also a more commonly used method to deal with tower resonance. Generally, in order to ensure that the speed of the unit can cross quickly, the power at point B is higher than that at point C, and the speed is allowed to cross upwards; the power at point D is lower than that at point A, and the speed is allowed to cross downwards. Figure 1

[0004] However, resonance crossing has an unavoidable defect, that is, for the wind speed interval that should originally run in the speed forbidden zone, the speed is forcibly maintained outside the speed forbidden zone, and the unit cannot run at the optimal speed, so the power generation of the unit will inevitably suffer losses. With the continuous increase of the single capacity of wind turbines, the speed of the unit is also continuously increased, and the power generation loss caused by setting the speed forbidden zone is increasingly significant. Moreover, the loss of power generation is proportional to the width of the speed forbidden zone, so the power generation loss of high-speed wind turbines is significantly increased than that of low-speed wind turbines. In addition, the degree of deviation of high-speed units from the optimal tip speed ratio on the speed boundary is also increasing, which will increase the possibility of stall of the unit.

[0005] Currently, there are very few power generation optimization methods for resonance crossing, and an effective control means is in urgent need. SUMMARY

[0006] The first purpose of the present application is to optimize the power generation loss problem caused by the speed forbidden zone set by the wind turbine due to resonance, especially for large-capacity high-speed wind turbines, to provide a wind turbine resonance crossing control method based on power optimization, which can effectively optimize the conditions of resonance crossing in real time, so as to better adjust the switching of the speed of the unit on the resonance boundary and improve the power generation of the wind turbine in the wind speed segment in the resonance interval.

[0007] ​The second object of the present application is to provide a power-optimal wind turbine resonance crossing control system.

[0008] The third object of the present application is to provide a storage medium.

[0009] The fourth object of the present application is to provide a computing device.

[0010] The first object of the present application is achieved by the following technical solution: a power-optimal wind turbine resonance crossing control method, first, obtaining the current average wind speed and average pitch angle of the wind turbine, calculating the tip speed ratio of the wind turbine running at the upper and lower boundaries of the speed forbidden zone at the average wind speed, then looking up the table to obtain the wind energy utilization coefficient corresponding to the tip speed ratio of the upper and lower boundaries of the speed forbidden zone at the average pitch angle, calculating the difference of the wind energy utilization coefficient when running at the upper and lower boundaries at the average wind speed, triggering the wind turbine up-crossing when the wind energy utilization coefficient of the wind turbine running at the upper boundary of the speed forbidden zone is greater and itself is maintained at the lower boundary of the forbidden zone, triggering the wind turbine down-crossing when the wind energy utilization coefficient of the wind turbine running at the lower boundary of the speed forbidden zone is greater and itself is maintained at the upper boundary of the lower forbidden zone, thereby optimizing the power generation of the wind turbine in the resonance interval wind speed section.

[0011] Further, assuming that the resonance speed of the wind turbine is ω0, the lower boundary of the speed forbidden zone is ω1, and the upper boundary is ω2, and ω1=(1-a)*ω0, ω2=(1+a)*ω0, a is a coefficient, 0

[0012] Obtaining the current external wind speed of the wind turbine, and obtaining the average wind speed U by sliding average filtering;

[0013] Calculating the tip speed ratio λ1 of the wind turbine running at the lower boundary ω1 and the tip speed ratio λ2 of the wind turbine running at the upper boundary ω2 at the average wind speed U;

[0014] Obtaining the pitch angle of each blade of the wind turbine, and calculating the average pitch angle Ω;

[0015] According to the Cp-Lambda performance curve of the blade, looking up the table to obtain the wind energy utilization coefficient Cp1 running at the lower boundary ω1 corresponding to the tip speed ratio λ1 and the wind energy utilization coefficient Cp2 running at the upper boundary ω2 corresponding to the tip speed ratio λ2 at the average pitch angle Ω;

[0016] Calculating the difference of the wind energy utilization coefficients Cp1 and Cp2, denoted as Cp bias ;

[0017] As the average wind speed U increases, when Cp biasWhen the difference is greater than a preset threshold alpha, alpha>0, and the rotating speed of the wind turbine is maintained at the lower boundary omega1, the wind turbine up-passing is triggered to lift the rotating speed of the wind turbine to the upper boundary omega2;

[0018] When the average wind speed U decreases, when Cp bias When the difference is less than a preset threshold -alpha, alpha>0, and the rotating speed of the wind turbine is maintained at the upper boundary omega2, the wind turbine down-passing is triggered to lower the rotating speed of the wind turbine to the lower boundary omega1.

[0019] Further, the calculation formula of the tip speed ratio lambda1 is as follows:

[0020] lambda1=omega1*R / (U*G)

[0021] In the formula, R is the impeller radius, and G is the transmission ratio.

[0022] Further, the calculation formula of the tip speed ratio lambda2 is as follows:

[0023] lambda2=omega2*R / (U*G)

[0024] In the formula, R is the impeller radius, and G is the transmission ratio.

[0025] Further, the Cp-Lambda performance curve can be updated in real time online through system identification.

[0026] Further, the calculation formula of the difference Cp bias is as follows:

[0027] Cp bias =Cp2-Cp1.

[0028] Further, the current external wind speed of the wind turbine is acquired through a wind speed sensor, the average value of a plurality of wind speed sensors is taken, and a sliding average filtering is performed to obtain the average wind speed U.

[0029] Further, the pitch angle of each blade of the wind turbine is acquired through a pitch angle sensor, the average value of the pitch angles of all the blades is taken to obtain the average pitch angle Omega.

[0030] The second object of the application is achieved by the following technical scheme: a wind turbine resonance passing control system based on power optimization, used for implementing the wind turbine resonance passing control method based on power optimization, comprising:

[0031] An average wind speed acquisition module, used for acquiring the current external wind speed of the wind turbine and obtaining the average wind speed U through sliding average filtering;

[0032] A first calculation module, used for calculating the tip speed ratio lambda1 when the wind turbine runs at the lower boundary omega1 and the tip speed ratio lambda2 when the wind turbine runs at the upper boundary omega2 under the average wind speed U.

[0033] an average pitch angle obtaining module, configured to obtain the pitch angle of each blade of the wind turbine and calculate an average pitch angle Omega;

[0034] a wind energy utilization coefficient obtaining module, configured to obtain, according to the Cp-Lambda performance curve of the blade, a wind energy utilization coefficient Cp1 corresponding to a tip speed ratio lambda1 running at a lower boundary omega1 and a wind energy utilization coefficient Cp2 corresponding to a tip speed ratio lambda2 running at an upper boundary omega2 under the average pitch angle Omega;

[0035] a second calculating module, configured to calculate the difference between the wind energy utilization coefficients Cp1 and Cp2, denoted as Cp bias ;

[0036] a crossing judgment module, configured to judge whether a crossing action needs to be performed, with the average wind speed U increasing, when Cp bias is greater than a preset threshold alpha, alpha>0, and the rotating speed of the wind turbine is maintained at the lower boundary omega1, triggering the wind turbine to up-cross, and lifting the rotating speed of the wind turbine to the upper boundary omega2; with the average wind speed U decreasing, when Cp bias is less than the preset threshold -alpha, alpha>0, and the rotating speed of the wind turbine is maintained at the upper boundary omega2, triggering the wind turbine to down-cross, and lowering the rotating speed of the wind turbine to the lower boundary omega1.

[0037] A third object of the present application is achieved by the following technical solution: a storage medium, storing a program, the program being executed by a processor to implement the wind turbine resonance crossing control method based on power optimization.

[0038] A fourth object of the present application is achieved by the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, the processor executing the program stored in the memory to implement the wind turbine resonance crossing control method based on power optimization.

[0039] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0040] The present application effectively optimizes the resonance crossing conditions in real time through reliable observation data and algorithm analysis, thereby better adjusting the switching of the rotating speed of the wind turbine on the resonance boundary and improving the power generation of the wind turbine in the resonance interval wind speed section, and effectively optimizing the power generation loss of the wind turbine in the resonance interval wind speed section. The wind speed condition for triggering the crossing is actually weakened, so the degree of deviation from the optimal tip speed ratio on the rotating speed boundary is reduced, thereby reducing the possibility of stall of the wind turbine. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1is a resonance crossing demonstration diagram; in the diagram, Generator Speed is the generator speed, Generator Torque is the generator torque, Optimal Trajectory is the optimal trajectory, Resonance Point is the resonance point, and Crossing Trajectory is the crossing trajectory.

[0042] Figure 2 is a flow chart of the method of the present application.

[0043] Figure 3 is a power comparison curve diagram of a certain unit when the method of the present application is used.

[0044] Figure 4 is a speed comparison curve diagram of a certain unit when the method of the present application is used.

[0045] Figure 5 is an architecture diagram of the system of the present application. DETAILED DESCRIPTION

[0046] The present application will be further described in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present application are not limited thereto.

[0047] Embodiment 1

[0048] As shown in Figure 2 , the embodiment discloses a wind turbine resonance crossing control method based on power optimization. First, the average wind speed and average pitch angle of the current external environment of the wind turbine are obtained, the tip speed ratio of the wind turbine running on the upper and lower boundaries of the speed forbidden zone at the average wind speed is calculated, and then the wind energy utilization coefficient corresponding to the tip speed ratio of the upper and lower boundaries of the speed forbidden zone at the average pitch angle is obtained by looking up the table. The difference of the wind energy utilization coefficient when running on the upper and lower boundaries at the average wind speed is calculated. When the wind energy utilization coefficient of the wind turbine running on the upper boundary of the speed forbidden zone is greater and itself is maintained on the lower boundary of the forbidden zone, the wind turbine up-crossing is triggered. When the wind energy utilization coefficient of the wind turbine running on the lower boundary of the speed forbidden zone is greater and itself is maintained on the upper boundary of the forbidden zone, the wind turbine down-crossing is triggered, thereby optimizing the power generation of the wind turbine in the resonance interval wind speed section.

[0049] Specifically, assuming that the resonance speed of the wind turbine is ω0, the lower boundary of the speed forbidden zone is ω1, and the upper boundary is ω2, and ω1=(1-a)*ω0, ω2=(1+a)*ω0, a is a coefficient, 0

[0050] The current external wind speed of the wind turbine is obtained by a wind speed sensor, the average value of multiple wind speed sensors is taken, and a sliding average filter is performed thereon to obtain the average wind speed U.

[0051] The tip speed ratio λ1 when the wind turbine operates at the lower boundary ω1 and the tip speed ratio λ2 when the wind turbine operates at the upper boundary ω2 at the average wind speed U are calculated according to the following formulas:

[0052] λ1 = ω1 * R / (U * G)

[0053] λ2 = ω2 * R / (U * G)

[0054] wherein R is the impeller radius and G is the gear ratio.

[0055] The pitch angle of each blade of the wind turbine is obtained by a pitch angle sensor, and the average pitch angle Ω is obtained by averaging the pitch angles of all the blades.

[0056] According to the Cp-Lambda performance curve of the blade (the Cp-Lambda performance curve can be updated in real time online through system identification), the wind energy utilization coefficient Cp1 corresponding to the tip speed ratio λ1 when operating at the lower boundary ω1 and the wind energy utilization coefficient Cp2 corresponding to the tip speed ratio λ2 when operating at the upper boundary ω2 at the average pitch angle Ω are obtained by table lookup.

[0057] The difference between the wind energy utilization coefficients Cp1 and Cp2 is calculated and denoted as Cp bias , and the calculation formula is as follows:

[0058] Cp bias = Cp2 - Cp1

[0059] As the average wind speed U increases, when Cp bias is greater than the preset threshold α, α > 0, and the speed of the wind turbine is maintained at the lower boundary ω1, the wind turbine is triggered to up-pass, and the speed of the wind turbine is lifted to the upper boundary ω2.

[0060] As the average wind speed U decreases, when Cp bias is less than the preset threshold -α, α > 0, and the speed of the wind turbine is maintained at the upper boundary ω2, the wind turbine is triggered to down-pass, and the speed of the wind turbine is lowered to the lower boundary ω1.

[0061] As Figure 3 and Figure 4 show, the power and speed comparison curve of the wind turbine when a certain unit uses the above-mentioned method of the embodiment is shown, and it can be seen from the figure that the experimental group effectively changes the state of the wind turbine maintained at the speed forbidden zone boundary, and obtains higher power generation through this.

[0062] Embodiment 2

[0063] The embodiment discloses a wind turbine resonance crossing control system based on power optimization, which is used to realize the wind turbine resonance crossing control method based on power optimization described in embodiment 1, as Figure 5As shown, the system comprises the following functional modules:

[0064] An average wind speed acquisition module is configured to acquire the current external wind speed of the wind turbine and obtain the average wind speed U through a sliding average filter.

[0065] A first calculation module is configured to calculate the tip speed ratio λ1 of the wind turbine when operating at the lower boundary ω1 and the tip speed ratio λ2 of the wind turbine when operating at the upper boundary ω2 under the average wind speed U.

[0066] An average pitch angle acquisition module is configured to acquire the pitch angle of each blade of the wind turbine and calculate the average pitch angle Ω.

[0067] A wind energy utilization coefficient acquisition module is configured to acquire the wind energy utilization coefficient Cp1 corresponding to the tip speed ratio λ1 when operating at the lower boundary ω1 and the wind energy utilization coefficient Cp2 corresponding to the tip speed ratio λ2 when operating at the upper boundary ω2 according to the Cp-Lambda performance curve of the blade under the average pitch angle Ω.

[0068] A second calculation module is configured to calculate the difference between the wind energy utilization coefficients Cp1 and Cp2, denoted as Cp. bias ;

[0069] A crossing judgment module is configured to judge whether the crossing action needs to be performed. As the average wind speed U increases, when Cp bias is greater than a preset threshold α, α>0, and the rotational speed of the wind turbine is maintained at the lower boundary ω1, the wind turbine is triggered to up-cross, and the rotational speed of the wind turbine is lifted to the upper boundary ω2. As the average wind speed U decreases, when Cp bias is less than a preset threshold -α, α>0, and the rotational speed of the wind turbine is maintained at the upper boundary ω2, the wind turbine is triggered to down-cross, and the rotational speed of the wind turbine is lowered to the lower boundary ω1.

[0070] Embodiment 3

[0071] The embodiment discloses a storage medium, which stores a program. When the program is executed by a processor, the power-optimal wind turbine resonance crossing control method in embodiment 1 is realized.

[0072] The storage medium in the embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a U disk, a mobile hard disk, and the like.

[0073] Embodiment 4

[0074] The embodiment discloses a computing device, comprising a processor and a memory for storing a processor-executable program, when the processor executes the program stored in the memory, the power-optimal wind turbine resonance ride-through control method described in embodiment 1 is realized.

[0075] The computing device described in the embodiment can be a desktop computer, a notebook computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC) or other terminal devices with processor functions.

[0076] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and are all included in the protection scope of the present application.

Claims

1. A wind turbine resonance ride-through control method based on power optimization is characterized by: First, the current average wind speed and average pitch angle of the wind turbine generator set are obtained, and the tip speed ratio of the wind turbine generator set operating at the upper and lower boundaries of the speed forbidden zone at the above average wind speed is calculated. Then, the wind energy utilization coefficient corresponding to the tip speed ratio of the upper and lower boundaries of the speed forbidden zone at the above average pitch angle is obtained by looking up the table. The difference between the wind energy utilization coefficients when the wind turbine generator set operates at the upper and lower boundaries at the above average wind speed is calculated. When the wind energy utilization coefficient of the wind turbine generator set operating at the upper boundary of the speed forbidden zone is greater and the wind turbine generator set itself is maintained at the lower boundary of the forbidden zone, the wind turbine generator set is triggered to cross over. When the wind energy utilization coefficient of the wind turbine generator set operating at the lower boundary of the speed forbidden zone is greater and the wind turbine generator set itself is maintained at the upper boundary of the lower forbidden zone, the wind turbine generator set is triggered to cross over, thereby optimizing the power generation of the wind turbine generator set within the wind speed segment of the resonance range. Assume that the resonant speed of the wind turbine is , the lower boundary of the speed restricted zone is , the upper boundary is ,and , do the following: Get the current external wind speed of the wind turbine and get the average wind speed through sliding average filtering ; Calculate the average wind speed of wind turbines Running below the lower boundary Tip speed ratio and runs on the upper boundary Tip speed ratio ; Get the pitch angle of each blade of the wind turbine and calculate the average pitch angle ; According to the Cp-Lambda performance curve of the blade, the average pitch angle is obtained by looking up the table. Tip speed ratio The corresponding operation is at the lower boundary Wind energy utilization coefficient and tip speed ratio The corresponding operation is at the upper boundary Wind energy utilization coefficient ; Calculating wind energy utilization coefficient and The difference is recorded as ; With the average wind speed Increase, when Greater than the preset threshold , and the speed of the wind turbine is maintained at the lower boundary When the wind turbine is triggered to cross over, the wind turbine speed is raised to the upper limit ; With the average wind speed Decline, when Less than the preset threshold , and the wind turbine speed is maintained at the upper limit When the wind turbine is triggered to cross over, the wind turbine speed is reduced to the lower boundary .

2. The wind turbine resonance ride-through control method based on power optimization according to claim 1 is characterized in that: The tip speed ratio The calculation formula is as follows: ； Where, is the impeller radius, is the transmission ratio.

3. The wind turbine resonance ride-through control method based on power optimization according to claim 1, characterized in that: The tip speed ratio The calculation formula is as follows: ； Where, is the impeller radius, is the transmission ratio.

4. The wind turbine resonance ride-through control method based on power optimization according to claim 1, characterized in that: The Cp-Lambda performance curve can be updated online in real time through system identification.

5. The wind turbine resonance ride-through control method based on power optimization according to claim 1, characterized in that: The difference The calculation formula is as follows: 。 6. The wind turbine resonance ride-through control method based on power optimization according to claim 1, characterized in that: The wind speed sensor is used to obtain the current external wind speed of the wind turbine. The average value of multiple wind speed sensors is taken and a sliding average filter is performed on it to obtain the average wind speed. .

7. The wind turbine resonance ride-through control method based on power optimization according to claim 1, characterized in that: The pitch angle of each blade of the wind turbine is obtained through the pitch angle sensor, and the average pitch angle of all blades is taken to obtain the average pitch angle .

8. A wind turbine resonance ride-through control system based on power optimization is characterized by: A wind turbine resonance ride-through control method based on power optimization for implementing any one of claims 1 to 7, comprising: The average wind speed acquisition module is used to obtain the current external wind speed of the wind turbine and obtain the average wind speed through sliding average filtering. ; The first calculation module is used to calculate the average wind speed of the wind turbine Running below the lower boundary Tip speed ratio and runs on the upper boundary Tip speed ratio ; The average pitch angle acquisition module is used to obtain the pitch angle of each blade of the wind turbine and calculate the average pitch angle ; The wind energy utilization coefficient acquisition module obtains the average pitch angle based on the Cp-Lambda performance curve of the blade by looking up the table. Tip speed ratio The corresponding operation is at the lower boundary Wind energy utilization coefficient and tip speed ratio The corresponding operation is at the upper boundary Wind energy utilization coefficient ; The second calculation module is used to calculate the wind energy utilization coefficient and The difference is recorded as ; The crossing judgment module is used to judge whether the crossing action needs to be executed. Increase, when Greater than the preset threshold , and the speed of the wind turbine is maintained at the lower boundary When the wind turbine is triggered to cross over, the wind turbine speed is raised to the upper limit ; With the average wind speed Decline, when Less than the preset threshold , and the wind turbine speed is maintained at the upper limit When the wind turbine is triggered to cross over, the wind turbine speed is reduced to the lower boundary .

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