An overspeed suppression control method, device and system for a wind turbine

Abstract

The present invention discloses a method, device and system for controlling overspeed suppression of a wind turbine generator set. The method comprises the following steps: obtaining the generator speed ω of the wind turbine generator set; gen , will ω gen and the speed set point ω ref Subtract the speed error to get the pitch speed PID control output value θ pid ; Get the acceleration Acc of the wind turbine, multiply it by the tower resistance gain coefficient to get the tower resistance pitch angle value θ damp ; Get the pitch angle θ of the wind turbine mes and generator speed overspeed ratio ω OverSpeed After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value θ is obtained fuzzy ; Set θ pid ,θ damp and θ fuzzy The three are superimposed to obtain the pitch angle command value θ ref The present invention does not rely on an accurate model of the controlled object, can overcome the influence of complex multivariable nonlinear factors, has strong robustness and anti-interference capabilities, and does not require additional hardware costs.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of wind power generation, and in particular to a method, device and system for controlling overspeed suppression of a wind turbine generator set. Background Art

[0002] Large-capacity, long-blade units have large inertia and delayed response of the pitch system, making overspeed a particularly prominent problem. Overspeed shutdown of the unit is prone to extreme loads, which has a significant impact on the life of key components of the unit and the safety of the entire unit.

[0003] Overspeed suppression is primarily designed for pitch controllers. Current solutions for suppressing overspeed include: 1. Accelerating the unit's pitch response by dynamically adjusting the gain scheduling value of the pitch PID control loop; 2. Actively identifying characteristic wind conditions using characteristic variables such as generator speed, generator speed deviation, and generator speed change rate, superimposing nonlinear pitch terms to perform advance pitch control; and 3. Using lidar hardware to identify turbulent wind and gusts in advance for advance pitch control. The aforementioned solutions accelerate the unit's pitch response and, by superimposing nonlinear pitch terms, impact the unit's stability, making it prone to instability. Furthermore, the use of radar equipment increases hardware costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: in response to the technical problems existing in the prior art, the present invention provides a wind turbine overspeed suppression control method, device and system with strong robustness and anti-interference ability without increasing hardware costs.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A method for controlling overspeed suppression of a wind turbine generator system, comprising the steps of:

[0007] Get the generator speed ω of the wind turbine gen , the generator speed ω gen and the speed set point ω ref Subtract the speed error to get the pitch speed PID control output value θ pid ;

[0008] Get the acceleration Acc of the wind turbine and multiply it by the tower resistance gain coefficient to get the tower resistance pitch angle θ damp ;

[0009] Get the pitch angle θ of the wind turbine mes and generator speed overspeed ratio ω OverSpeed After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value θ is obtained fuzzy ;

[0010] The pitch speed PID control output value θpid , tower drag pitch angle value θ damp , adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy The three are superimposed to obtain the pitch angle command value θ ref , transmitted to the pitch actuator for pitch control.

[0011] As a further improvement of the above technical solution:

[0012] The specific process of adaptive fuzzy overspeed suppression is:

[0013] Generator speed overspeed ratio ω OverSpeed After filtering, the generator speed overspeed ratio filter value ω is obtained MovOvSpd ;

[0014] Generator speed overspeed ratio filter value ω MovOvSpd and pitch angle θ mes The input observation quantity of the fuzzy controller is fuzzified, and then fuzzy reasoning is performed according to the fuzzy control rule table, and then defuzzification is performed according to the center of gravity method to obtain the control quantity U of the fuzzy controller. The control quantity U is multiplied by the adaptive adjustment factor K. u Get the adaptive fuzzy overspeed suppression additional pitch rate v fuzzy , v fuzzy Multiply by the step size to convert into the adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy .

[0015] Regulation factor K u According to the generator speed overspeed ratio filter value ω MovOvSpd and the overspeed ratio change rate for adaptive adjustment.

[0016] Regulation factor K u The specific process of adaptive adjustment is as follows:

[0017] Generator speed overspeed ratio filter value ω MovOvSpd The k-th step updates the overspeed ratio to ω MovOvSpd (k), the k+1th step updates the overspeed ratio to ω MovOvSpd (k+1), calculate the overspeed ratio change rate ω MovOvSpd (k+1)-ω MovOvSpd (k) / ΔT, ΔT is the sampling period;

[0018] According to the overspeed ratio ω MovOvSpd (k) and the rate of change of the overspeed ratio ω MovOvSpd (k+1)-ω MovOvSpd (k) / ΔT, for the adjustment factor K u Perform adaptive adjustment.

[0019] According to the overspeed ratio ω MovOvSpd(k) and the rate of change of the overspeed ratio ω MovOvSpd (k+1)-ω MovOvSpd (k) / ΔT, for the adjustment factor K u The specific process of adaptive adjustment is: if the overspeed ratio ω MovOvSpd (k) is less than the threshold ω1, K u Set to 0; if the overspeed ratio ω MovOvSpd (k) is greater than or equal to the threshold ω1, according to ω MovOvSpd (k) and ω MovOvSpd (k+1)-ω MovOvSpd The product of (k) / ΔT is used to adaptively set K u value.

[0020] According to ω MovOvSpd (k) and ω MovOvSpd (k+1)-ω MovOvSpd The product of (k) / ΔT is used to adaptively set K u The specific process of the value is:

[0021] where ω MovOvSpd (k) is greater than the threshold ω2 and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is positive, K u The value is within a first preset threshold, wherein the threshold ω2 is greater than the threshold ω1;

[0022] where ω MovOvSpd (k) is less than the threshold ω2 and greater than the threshold ω1, and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is positive, K u The value is within a second preset threshold;

[0023] ω MovOvSpd (k) is greater than the threshold ω2 and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is negative, K u The value is within a second preset threshold;

[0024] ω MovOvSpd (k) is less than the threshold ω2 and greater than the threshold ω1, and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is negative, K u The value is within a third preset threshold; wherein the first preset threshold>the second preset threshold>the third preset threshold.

[0025] After obtaining the acceleration Acc of the wind turbine, it is processed by leading and lagging filtering, and then multiplied by the tower resistance gain coefficient to obtain the tower resistance pitch angle value θ damp .

[0026] After the speed error is calculated and limited by PID, the pitch speed PID control output value θ is obtained. pid .

[0027] The present invention also discloses a wind turbine overspeed suppression control device, which includes a speed error calculation module, a pitch speed PID module, a tower resistance module, an adaptive fuzzy overspeed suppression module and a pitch control module;

[0028] The speed error calculation module is used to obtain the generator speed ω of the wind turbine generator set. gen , the generator speed ω gen and the speed set point ω ref Subtract and get the speed error;

[0029] The pitch speed PID module is used to obtain the pitch speed PID control output value θ according to the speed error. pid ;

[0030] The tower resistance module is used to obtain the acceleration Acc of the wind turbine and multiply it by the tower resistance gain coefficient to obtain the tower resistance pitch angle value θ. damp ;

[0031] The adaptive fuzzy overspeed suppression module is used to obtain the pitch angle θ of the wind turbine mes and generator speed overspeed ratio ω OverSpeed After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value θ is obtained fuzzy ;

[0032] The variable pitch control module is used to control the pitch speed PID output value θ pid , tower drag pitch angle value θ damp , adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy The three are superimposed to obtain the pitch angle command value θ ref , transmitted to the pitch actuator for pitch control.

[0033] The present invention also discloses a wind turbine overspeed suppression control system, comprising a memory and a processor, wherein the memory stores a computer program, and the computer program executes the steps of the above method when executed by the processor.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] The present invention performs fuzzification and fuzzy rule design based on the generator speed overspeed ratio and pitch angle. Through fuzzy reasoning and defuzzification, the fuzzy control output value is obtained. The fuzzy control output value is multiplied by an adaptive adjustment factor to obtain an additional variable pitch rate value. The variable pitch rate is multiplied by the time step to convert it into an additional variable pitch angle. The additional additional variable pitch angle is superimposed on the traditional variable pitch closed-loop PID control to achieve the purpose of reducing the generator speed. The present invention does not rely on a precise controlled object model and can overcome the influence of complex multivariable nonlinear factors. It has strong robustness and anti-interference capabilities without increasing hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a control block diagram of a control device in an embodiment of the present invention.

[0037] Figure 2 This is a control block diagram of an embodiment of the control method of the present invention.

[0038] Figure 3 This is a control block diagram of an embodiment of the adaptive fuzzy overspeed suppression method of the present invention.

[0039] Figure 4 FIG. 4 is a flow chart of an embodiment of the adaptive factor adjustment method of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 2 As shown, the adaptive fuzzy overspeed suppression control method according to the embodiment of the present invention includes the following steps:

[0042] Get the generator speed ω gen , after filtering, and then compared with the speed setting point ω ref Subtract the speed error and use it as the input of the pitch speed PID controller. The pitch speed PID control output value θ is obtained after calculation and limiting by the PID controller. pid ;

[0043] The acceleration Acc measured by the vibration monitor is processed by lead-lag filtering and then multiplied by the tower drag gain coefficient to obtain the tower drag pitch angle value θ. damp ;

[0044] According to the measured pitch angle and the calculated generator speed overspeed ratio, the adaptive fuzzy overspeed suppression compensation pitch angle value θ is obtained after adaptive fuzzy overspeed suppression. fuzzy ;

[0045] The pitch speed PID control output value θ pid , tower drag pitch angle value θdamp and adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy The three are superimposed to obtain the pitch angle command value θ ref , is sent to the pitch actuator, which inputs the pitch command value θ ref Perform pitch control.

[0046] like Figure 3 As shown in Figure 2, the specific process of the adaptive fuzzy overspeed suppression method is as follows:

[0047] ω OverSpeed is the generator speed overspeed ratio, The generator speed overspeed ratio is obtained by filtering ω MovOvSpd ,θ mes is the measured pitch angle;

[0048] Generator speed overspeed ratio filter value ω MovOvSpd and pitch angle θ mes As the input observation of the fuzzy controller, v fuzzy is the control quantity of the fuzzy controller, and the input quantity is the generator speed overspeed ratio filter value ω MovOvSpd The domain is [0,20], and the fuzzy subset is {ZO, PS, PM, PB}, where ZO is 0, PS is positive small, PM is positive medium, and PB is positive large. The triangular membership function is used for fuzzification; the input quantity pitch angle θ mes The domain of the output pitch speed is [0, 3], the fuzzy subsets are {ZO, PS, PM, PB}, and the fuzzification is performed using a triangular membership function. The domain of the output pitch speed is [0, 3], the fuzzy subsets are {ZO, PS, PM, PB}, and the fuzzification is performed using a Gaussian membership function. A fuzzy rule table is developed based on engineering experience. Mamdani's Max-Min fuzzy reasoning and the center of gravity method are used for defuzzification to obtain the fuzzy controller control quantity U. The fuzzy control quantity U is multiplied by the adaptive adjustment factor K. u Get the adaptive fuzzy overspeed suppression additional pitch rate v fuzzy , v fuzzy Multiply by the step size to convert into the adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy .

[0049] The adjustment factor K u and the generator speed overspeed ratio filter value ω MovOvSpd Has a strong correlation, such as K u If the value is too small, the ability to suppress overspeed is weak, and overspeed faults are likely to occur in strong gust conditions; u If the value is too large, the output value of the fuzzy overspeed controller will be large, the overspeed suppression time will be too long, which will affect the power generation performance of the unit and increase the fatigue load on the bottom of the unit. uThe value of is crucial to control performance, and its specific adjustment method is as follows:

[0050] like Figure 4 As shown, the generator speed overspeed ratio ω OverSpeed After filtering, it is ω MovOvSpd , the kth step updates the overspeed ratio to ω MovOvSpd (k), the k+1th step updates the overspeed ratio to ω MovOvSpd (k+1), calculate the overspeed ratio change rate ω MovOvSpd (k+1)-ω MovOvSpd (k) / ΔT, ΔT is the sampling period; if the overspeed ratio ω MovOvSpd (k) is less than the threshold ω1, K u Set to 0; if the overspeed ratio ω MovOvSpd (k) is greater than or equal to the threshold ω1, according to ω MovOvSpd (k) and ω MovOvSpd (k+1)-ω MovOvSpd The product of (k) / ΔT is used to adaptively set K u value; where ω MovOvSpd (k) is large and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is positive, K u Increase the value to quickly suppress the speed increase; MovOvSpd (k) is smaller and greater than the threshold ω1, ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is positive, K u Moderate value; MovOvSpd (k) is large and ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is negative, K u Moderate value; MovOvSpd (k) is smaller and greater than the threshold ω1, ω MovOvSpd (k+1)-ω MovOvSpd When (k) / ΔT is negative, K u The value is smaller.

[0051] The present invention performs fuzzification and fuzzy rule design based on the generator speed overspeed ratio and pitch angle. Through fuzzy reasoning and defuzzification, the fuzzy control output value is obtained. The fuzzy control output value is multiplied by an adaptive adjustment factor to obtain an additional variable pitch rate value. The variable pitch rate is multiplied by the time step to convert it into an additional variable pitch angle. The additional additional variable pitch angle is superimposed on the traditional variable pitch closed-loop PID control to achieve the purpose of reducing the generator speed. The present invention does not rely on a precise controlled object model and can overcome the influence of complex multivariable nonlinear factors. It has strong robustness and anti-interference capabilities without increasing hardware costs.

[0052] This invention addresses extreme turbulence and gusty wind conditions by constructing a fuzzy overspeed suppression identification method using the generator speed overspeed ratio and pitch angle characteristic variables, effectively identifying overspeed conditions in the unit. This invention also designs an adaptive fuzzy overspeed suppression controller that adaptively adjusts the pitch angle according to different overspeed conditions defined by the unit, suppressing overspeed while simultaneously reducing the unit's ultimate load. This controller exhibits strong robustness and is suitable for complex nonlinear systems.

[0053] like Figure 1 As shown, an embodiment of the present invention further provides a wind turbine overspeed suppression control device, including a speed error calculation module, a pitch speed PID module, a tower resistance module, an adaptive fuzzy overspeed suppression module and a pitch control module;

[0054] Speed error calculation module, used to obtain the generator speed ω of the wind turbine gen , the generator speed ω gen and the speed set point ω ref Subtract and get the speed error;

[0055] Pitch speed PID module, used to obtain the pitch speed PID control output value θ based on the speed error pid ;

[0056] The tower resistance module is used to obtain the acceleration Acc of the wind turbine and multiply it by the tower resistance gain coefficient to obtain the tower resistance pitch angle value θ damp ;

[0057] Adaptive fuzzy overspeed suppression module, used to obtain the pitch angle θ of the wind turbine mes and generator speed overspeed ratio ω OverSpeed After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value θ is obtained fuzzy ;

[0058] The variable pitch control module is used to control the pitch speed PID output value θ pid , tower drag pitch angle value θ damp , adaptive fuzzy overspeed suppression compensation pitch angle value θ fuzzy The three are superimposed to obtain the pitch angle command value θ ref , transmitted to the pitch actuator for pitch control.

[0059] An embodiment of the present invention further provides a wind turbine overspeed suppression control system, comprising a memory and a processor. The memory stores a computer program that, when executed by the processor, executes the steps of the above-described method. The control device and control system of the present invention correspond to the above-described control method and similarly possess the advantages described above.

[0060] As shown in this disclosure and the claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not specifically refer to the singular, but also include the plural. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0061] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A wind turbine overspeed suppression control method, characterized in that: Including steps: Get the generator speed of the wind turbine , the generator speed and speed set point Subtract the speed error to get the pitch speed PID control output value. ; Get the acceleration of the wind turbine , multiplied by the tower drag gain coefficient to obtain the tower drag pitch angle value ; Get the pitch angle of the wind turbine and generator speed overspeed ratio After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value is obtained ; The pitch speed PID control output value , Tower drag pitch angle value , adaptive fuzzy overspeed suppression compensation pitch angle value The three are superimposed to obtain the pitch angle command value , transmitted to the pitch actuator for pitch control; The specific process of adaptive fuzzy overspeed suppression is: Generator speed overspeed ratio After filtering, the generator speed overspeed ratio filter value is obtained ; Generator speed overspeed ratio filter value With pitch angle The input observation quantity of the fuzzy controller is fuzzified, and then fuzzy reasoning is performed according to the fuzzy control rule table, and then defuzzification is performed according to the center of gravity method to obtain the control quantity of the fuzzy controller. , control quantity Multiply by the adaptive adjustment factor Get the adaptive fuzzy overspeed suppression additional pitch rate , Multiply by the step size to convert into the adaptive fuzzy overspeed suppression compensation pitch angle value ; Regulatory Factors According to the generator speed overspeed ratio filter value Perform adaptive adjustments; Regulatory Factors The specific process of adaptive adjustment is as follows: Generator speed overspeed ratio filter value The k-th step length updates the overspeed ratio as , the k+1th step length updates the overspeed ratio to , calculate the overspeed ratio change rate , is the sampling period; According to the overspeed ratio and overspeed ratio change rate , the regulatory factor Perform adaptive adjustments; According to the overspeed ratio and overspeed ratio change rate , the regulatory factor The specific process of adaptive adjustment is: if the overspeed ratio Less than threshold , Set to 0; if the overspeed ratio Greater than or equal to the threshold ,according to and Make adaptive settings value; according to and Make adaptive settings The specific process of the value is: in Greater than threshold and For the positive time, The value is within a first preset threshold, where the threshold Greater than threshold ; in Less than threshold and greater than the threshold ,and For the positive time, The value is within a second preset threshold; Greater than threshold and When it is negative, The value is within a second preset threshold; Less than threshold and greater than the threshold ,and When it is negative, The value is within a third preset threshold; wherein the first preset threshold>the second preset threshold>the third preset threshold.

2. The wind turbine overspeed suppression control method according to claim 1, characterized in that: According to the generator speed overspeed ratio filter value , pitch angle The adaptive fuzzy overspeed suppression control module is designed based on the overspeed ratio change rate to obtain the overspeed suppression compensation pitch angle value. .

3. A wind turbine overspeed suppression control device, used to execute the wind turbine overspeed suppression control method according to claim 1 or 2, characterized in that: It includes speed error calculation module, pitch speed PID module, tower resistance module, adaptive fuzzy overspeed suppression module and pitch control module; The speed error calculation module is used to obtain the generator speed of the wind turbine , the generator speed and speed set point Subtract and get the speed error; The pitch speed PID module is used to obtain the pitch speed PID control output value according to the speed error ; The tower resistance module is used to obtain the acceleration of the wind turbine , multiplied by the tower drag gain coefficient to obtain the tower drag pitch angle value ; The adaptive fuzzy overspeed suppression module is used to obtain the pitch angle of the wind turbine and generator speed overspeed ratio After adaptive fuzzy overspeed suppression, the adaptive fuzzy overspeed suppression compensation pitch angle value is obtained ; The variable pitch control module is used to control the pitch speed PID output value , Tower drag pitch angle value , adaptive fuzzy overspeed suppression compensation pitch angle value The three are superimposed to obtain the pitch angle command value , transmitted to the pitch actuator for pitch control.

4. A wind turbine overspeed suppression control system, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is run by the processor, the steps of the method according to any one of claims 1 to 2 are executed.

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