A method for improving the moment of inertia of a wind turbine simulator based on feedforward bias suppression

Abstract

The present invention aims at the abnormal speed fluctuation phenomenon of wind turbine simulators using existing inertia compensation strategies when simulating large inertia wind turbines, and proposes a method for improving the rotational inertia of wind turbine simulators based on feedforward deviation suppression. First, a discrete mathematical model of the wind turbine simulator is constructed, and the characteristic equation of the model is used to determine the torque deviation component generated by the wind turbine simulator transmission system due to system delay. Then, a torque deviation suppressor is designed for the torque deviation component, and the feedforward torque deviation suppressor is used to scale the torque component in advance, thereby eliminating the unbalanced torque generated in the torque compensation loop. The present invention solves the problem of abnormal speed fluctuation in the simulator by improving the inertia compensation strategy, and breaks through the existing wind turbine simulator that can only simulate the mechanical dynamics of more than ten times the actual wind turbine, and can accurately simulate the mechanical dynamics of a wind turbine with a rotational inertia that is a hundred times greater than its own, greatly improving the simulation multiple of the simulator and making it easy to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of wind turbine simulation experiments, and in particular relates to a method for improving the rotational inertia of a wind turbine simulator based on feedforward deviation suppression. Background Art

[0002] Wind turbine simulators are used to simulate the wind turbine characteristics of actual wind turbines, including the slow mechanical dynamic characteristics and electromagnetic dynamic characteristics of actual wind turbines. As the capacity of wind turbines increases, wind power companies must conduct sufficient condition verification and performance testing to develop wind turbines of different models and for different scenarios.

[0003] However, relying on actual wind farms to carry out relevant wind turbine tests not only increases costs, but also has problems such as low safety factor, long test cycle, restrictions by the natural environment, and difficulty in ensuring system stability control. Although some scientific research institutions and laboratories have facilities for wind power system development and testing, they are also limited by climatic conditions, sites, funds and other issues, and have almost no ability to build actual wind turbine experimental systems, or even WM-class large wind turbine test systems. Therefore, it is usually necessary to build a complete set of wind turbine simulators to replace actual wind turbine generators and carry out testing and research on actual wind turbines, which not only ensures the safety of researchers and reduces development costs, but also enables wind turbine power generation, grid-connected control and other functional tests to be realized in the laboratory, greatly facilitating the technical development and research of scientific researchers in the fields of wind turbine control and wind turbine power generation.

[0004] The inertia compensation strategy that the existing wind turbine simulator should have is to add an inertia compensation loop in the transmission chain and use the differential method to obtain the speed acceleration to calculate the compensation torque. However, since there is a one-step acceleration lag in the acceleration calculation and there is also a communication lag in the actual experimental system, the inertia compensation strategy of the k0+1 order filter is used to suppress the delay effect. Considering the existing wind turbines, especially the MW-class full-power wind turbines of wind power companies, their rotational inertia has exceeded 1000kgm 2 , its moment of inertia will be scaled up to a hundred times on a KW-class low-power dynamic model platform. However, although the wind turbine simulator using this inertia compensation strategy can simulate the mechanical dynamics of an actual wind turbine with a certain multiple of its own moment of inertia, the simulators including all existing inertia compensation strategies cannot accurately simulate the mechanical dynamics of a wind turbine with a moment of inertia a hundred times greater than its own. Therefore, it is urgent to propose a compensation method that can significantly increase the multiple of the simulated moment of inertia of the simulator. Summary of the invention

[0005] Aiming at the problem that the wind turbine simulator with inertia compensation strategy adopted in the prior art is difficult to accurately simulate the mechanical dynamics of a large inertia wind turbine, the present invention proposes a method for improving the rotational inertia of a wind turbine simulator based on feedforward deviation suppression.

[0006] The technical solution to achieve the purpose of the present invention is: a method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression, comprising the following steps:

[0007] Step 1, construct a discrete mathematical model of a wind turbine simulator including system delay;

[0008] Step 2, solving the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator;

[0009] Step 3, determining the torque deviation component of the wind turbine simulator transmission system caused by system delay;

[0010] Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention only improves the inertia compensation strategy, adds a torque deviation inhibitor on the basis of the existing inertia compensation strategy, and utilizes the advance scaling torque component of the feedforward torque deviation inhibitor to eliminate the unbalanced torque generated in the torque compensation loop, thereby solving the problem of abnormal speed fluctuations in the simulator and is easy to operate.

[0013] (2) The present invention breaks through the problem that existing wind turbine simulators can only simulate the mechanical dynamics of an actual wind turbine at a dozen times, and can accurately simulate the mechanical dynamics of a wind turbine with a rotational inertia that is a hundred times greater than its own, greatly improving the simulation multiple of the simulator.

[0014] The present invention will be further described below in conjunction with specific implementations and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the transmission chain structure in a wind turbine simulator with system delay in an embodiment of the present invention.

[0016] Figure 2 Schematic diagram of the monotonicity of the function y′(r) in an embodiment of the present invention.

[0017] Figure 3 Schematic diagram of a wind turbine simulator model using a feedforward torque deviation inhibitor in an embodiment of the present invention.

[0018] Figure 4The structure diagram of the dynamic model experimental system of the wind turbine used in the embodiment of the present invention.

[0019] Figure 5 Schematic diagram of the speed curve measured by the existing inertia compensation strategy.

[0020] Figure 6 It is a schematic diagram of a rotation speed curve after applying a method for increasing the rotational inertia of a wind turbine simulator based on feedforward deviation suppression in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] A method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression comprises the following steps:

[0022] Step 1, construct a discrete mathematical model of a wind turbine simulator including system delay;

[0023] The actual wind turbine generator set is a complex system of pneumatic-mechanical-electrical coupling, which can be mainly divided into three parts: pneumatic part, mechanical structure part and electromagnetic dynamic part. However, the wind turbine simulator does not have a wind rotor, and mainly includes three parts: wind rotor simulation system, power generation grid connection system and PLC-based digital control system. The wind turbine simulator system is designed to simulate the process of wind turbines converting wind energy into electrical energy, mainly realizing the electromechanical dynamic simulation of wind speed model, wind rotor aerodynamic model, transmission chain model and grid connection model, while ignoring mechanical structure models such as blades and towers.

[0024] The present invention focuses on the simulation of the mechanical dynamics of the actual wind turbine by the wind turbine simulator, and therefore does not consider the electromagnetic dynamics, specifically:

[0025] Step 1-1, the wind turbine simulator adopts the blade element-momentum theory and realizes the modeling of the wind wheel aerodynamic model based on the wind energy utilization coefficient curve (Cp-λ curve) model;

[0026] Build the aerodynamic model:

[0027] T a =0.5ρπR 2 v 3 C p (λ) / ω

[0028] λ=ωR / v

[0029] Where ρ is the air density, R is the radius of the wind wheel, v is the wind speed, C p (λ) represents the wind energy utilization coefficient, and its value is related to the blade tip speed ratio λ and the pitch angle β. a represents the aerodynamic torque input to the simulator system, ω represents the angular velocity of the wind wheel;

[0030] Step 1-2: Build the transmission chain model:

[0031] The wind turbine simulator has almost the same topology as the actual wind turbine, but the moment of inertia J s Much smaller than the actual wind turbine's moment of inertia J t In order to make the output speed of the transmission chains of the two the same, the fan model is simplified and the output torque expression of the fan simulator is obtained:

[0032]

[0033] This expression consists of two parts. The first part is T a The second part (J t -J s )ω g It represents the compensation torque calculated according to the acceleration of the transmission chain of the experimental system, that is, the goal of inertia compensation is achieved through torque compensation.

[0034] The wind turbine controller adopts the optimal torque method to realize the MPPT control of the wind turbine set.

[0035] However, the actual wind turbine simulator needs to communicate data through the field bus to achieve stable control of the wind turbine. Although the field bus communication is stable, its communication delay is still a multiple of the calculation time of the transmission control system. Assuming that the delay is an integer-order delay of the system discrete time step T, that is:

[0036] τ=k0·T

[0037]

[0038] Where Ts is the output torque of the wind turbine simulator, J s To simulate the moment of inertia, J t is the actual moment of inertia, is the simulator speed acceleration, which is calculated by differentiating the speed after acquisition; τ represents the communication time lag of the wind turbine simulator, T represents the control period of the wind turbine simulator, k0 represents the order of the communication time lag, k0 = 1, 2, 3…;

[0039] In order to suppress the influence of one-step acceleration delay caused by communication delay and acceleration calculation, the system has a k0+1-order system delay. Therefore, a k0+1-order filter is used to ensure system stability. N(z) is the k0+1-order filter in the transmission chain, α d represents the k0+1 order filter parameters in the wind turbine simulator.

[0040] Step 2: Solve the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator, specifically:

[0041] Step 2-1, determine the transfer function of the wind turbine simulator transmission system:

[0042]

[0043] Among them, α d represents the filter parameters, J s To simulate the moment of inertia, J t is the actual moment of inertia, k0 represents the order of communication delay, k0 = 1, 2, 3…;

[0044] Step 2-2, determine the characteristic equation of the transfer function:

[0045]

[0046] It has k0+1 poles in the complex plane distributed at:

[0047]

[0048] Let z = re jθ ,r∈R,θ∈[0,2π], perform polar coordinate transformation, and substitute it into the above formula to obtain:

[0049]

[0050] is equivalent to:

[0051]

[0052] |z|<1 is equivalent to |r|<1, and the necessary and sufficient conditions for the stability of the wind turbine simulator transmission system with system delay using the equivalent k0+1 order filter are obtained: All real solutions of the equation system (10) |r|<1;

[0053] Let the function To find out whether the real number solution of the equation when y(r)=0 is in the interval [-1,1], take the derivative of y(r) and get:

[0054]

[0055] Let y′(r)=0, and we get that the equation has only one pole 0. In the interval [-1,1], the monotonic characteristics of the above equation are as follows:

[0056] When r>0, the original function is monotonically increasing;

[0057] When r<0, and k0 is an odd number, the equation is monotonically decreasing;

[0058] When r>0, if k0 is an even number, the equation is monotonically increasing.

[0059] The simulator system is stable and all solutions in the complex plane satisfy |r|<1.

[0060] get:

[0061]

[0062] Combined with the system stability condition, we get:

[0063]

[0064] Step 2-3: According to the symmetric characteristics of the original function, the value of the filter coefficient is related to the odd and even value of k0, thereby determining the filter parameter α of the wind turbine simulator d :

[0065]

[0066] Step 3: Determine the torque deviation component of the wind turbine simulator transmission system caused by system delay, specifically:

[0067] Step 3-1: The transfer function H″ of the wind turbine simulator transmission system imp_wts (z) Perform inverse z transformation to obtain the time domain response expression of the simplified transmission model of the wind turbine simulator using the k0+1 order filter:

[0068]

[0069] Where a′ wts (k) is the output acceleration of the transmission chain, a wt (k), a′ d (k) are the response components of the output acceleration, where:

[0070]

[0071] It can be seen that the existing wind turbine simulator still has a new deviation component a′ compared with the actual wind turbine d , causing abnormal speed fluctuations in the simulator.

[0072] However, since the system delay occurs in the feedback loop of the transmission chain, it is necessary to further analyze the specific factors that cause abnormal speed fluctuations; therefore, the transmission chain feedback loop expression of the wind turbine simulator is analyzed:

[0073]

[0074] It can be seen that the deviation of the torque output in its feedback loop is related to both the communication time lag and the simulation multiple;

[0075] Step 3-2: Perform an inverse z transform on the transmission chain feedback loop of step 3-1 to obtain the time domain expression of the feedback loop of the wind turbine simulator, thereby determining the torque deviation component caused by the system delay:

[0076]

[0077] Among them, f2(k) is the torque deviation component between the feedback loop of the wind turbine simulator model and the actual wind turbine. The torque deviation is expressed as acceleration r(k), that is, the speed acceleration of the simulator. As an input, the simulator will experience abnormal speed fluctuations when simulating the mechanical dynamics of a wind turbine simulator with a large moment of inertia.

[0078] Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator, specifically:

[0079] A torque deviation suppressor Z(k) is constructed at the driving torque input end of the wind turbine simulator system. In order to make the wind turbine simulator with the torque deviation suppressor have the same speed dynamics as the actual wind turbine, the transmission chains of the two need to have the same topological structure model, which are as follows:

[0080] H1(k)=1 / J t

[0081] H2(k)=Z(k)·h(k)

[0082]

[0083] Among them, H1(k) is the actual wind turbine transmission chain model, and H2(k) is the wind turbine simulator transmission chain model using the feedforward torque bias suppression strategy;

[0084] Let H1(k)=H2(k), we get:

[0085]

[0086] In order to make the system respond as quickly as possible, the poles of the system are configured at the origin of the z plane, and the filter coefficient α of the high-order filter is obtained. d Take the best:

[0087] Then the filter parameter α d The optimal value of α d opt for:

[0088]

[0089] At this time, the poles of the wind turbine simulator model considering the system delay are all located at the origin, and its transfer function is consistent with the transfer function of the actual wind turbine system.

[0090] A wind turbine simulator rotation inertia enhancement system based on feedforward deviation suppression includes the following modules:

[0091] Model building module: used to build a discrete mathematical model of a wind turbine simulator including system delay;

[0092] Parameter determination module: used to determine the filter parameters of the wind turbine simulator;

[0093] Torque deviation component module: used to determine the torque deviation component of the wind turbine simulator transmission system caused by system delay;

[0094] Torque deviation suppression module: used to construct a torque deviation suppressor according to the determined torque deviation component, so as to increase the moment of inertia multiple of the wind turbine simulator.

[0095] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the following steps are implemented:

[0096] Step 1, construct a discrete mathematical model of a wind turbine simulator including system delay;

[0097] Step 2, solving the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator;

[0098] Step 3, determining the torque deviation component of the wind turbine simulator transmission system caused by system delay;

[0099] Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator.

[0100] A computer storable medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0101] Step 1, construct a discrete mathematical model of a wind turbine simulator including system delay;

[0102] Step 2, solving the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator;

[0103] Step 3, determining the torque deviation component of the wind turbine simulator transmission system caused by system delay;

[0104] Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator.

[0105] Example

[0106] A method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression comprises the following steps:

[0107] Step 1, construct a discrete mathematical model of a wind turbine simulator including system delay;

[0108] The actual wind turbine generator set is a complex system of pneumatic-mechanical-electrical coupling, which can be mainly divided into three parts: pneumatic part, mechanical structure part and electromagnetic dynamic part. However, the wind turbine simulator does not have a wind rotor, and mainly includes three parts: wind rotor simulation system, power generation grid connection system and PLC-based digital control system. The wind turbine simulator system is designed to simulate the process of wind turbines converting wind energy into electrical energy, mainly realizing the electromechanical dynamic simulation of wind speed model, wind rotor aerodynamic model, transmission chain model and grid connection model, while ignoring mechanical structure models such as blades and towers.

[0109] The present invention focuses on the simulation of the mechanical dynamics of the actual wind turbine by the wind turbine simulator, and therefore does not consider the electromagnetic dynamics, specifically:

[0110] Step 1-1, the wind turbine simulator adopts the blade element-momentum theory and realizes the modeling of the wind wheel aerodynamic model based on the wind energy utilization coefficient curve (Cp-λ curve) model;

[0111] Build the aerodynamic model:

[0112] T a =0.5ρπR 2 v 3 C p (λ) / ω

[0113] λ=ωR / v

[0114] Where ρ is the air density, R is the radius of the wind wheel, v is the wind speed, C p (λ) represents the wind energy utilization coefficient, and its value is related to the blade tip speed ratio λ and the pitch angle β. a represents the aerodynamic torque input to the simulator system, ω represents the angular velocity of the wind wheel;

[0115] Step 1-2: Build the transmission chain model:

[0116] The wind turbine simulator has almost the same topology as the actual wind turbine, but the moment of inertia J s Much smaller than the actual wind turbine's moment of inertia J t In this embodiment, let J s =0.72, J t=72, that is, the simulation multiple is 100. In order to make the output speed of the transmission chains of the two the same, the fan model is simplified and the output torque expression of the fan simulator is obtained:

[0117]

[0118] This expression consists of two parts. The first part is T a The second part (J t -J s )ω g It represents the compensation torque calculated according to the acceleration of the transmission chain of the experimental system, that is, the goal of inertia compensation is achieved through torque compensation.

[0119] The wind turbine controller adopts the optimal torque method to realize the MPPT control of the wind turbine set.

[0120] However, the actual wind turbine simulator needs to communicate data through the field bus to achieve stable control of the wind turbine. Although the field bus communication is stable, its communication delay is still a multiple of the calculation time of the transmission control system. Assuming that the delay is an integer-order delay of the system discrete time step T, that is:

[0121] τ=k0·T

[0122]

[0123] Where Ts is the output torque of the wind turbine simulator, J s To simulate the moment of inertia, J t is the actual moment of inertia, is the simulator speed acceleration, which is calculated by differentiating the speed after acquisition; τ represents the communication time lag of the wind turbine simulator, T represents the control period of the wind turbine simulator, k0 represents the order of the communication time lag, k0 = 1, 2, 3…;

[0124] In this embodiment, the actual measurement shows that the communication delay τ is 120-140ms, and the simulator is set to control the cycle of 40ms, so k0=3;

[0125] In order to suppress the influence of one-step acceleration delay caused by communication delay and acceleration calculation, the system has a k0+1-order system delay. Therefore, a k0+1-order filter is used to ensure system stability. N(z) is the k0+1-order filter in the transmission chain, α d represents the k0+1 order filter parameters in the wind turbine simulator.

[0126] Thus, a discrete mathematical model of the wind turbine simulator is obtained. The schematic diagram of the transmission chain structure in the wind turbine simulator in this embodiment is shown in FIG. Figure 1 shown.

[0127] The aerodynamic model of the wind turbine simulator calculates its aerodynamic torque. The aerodynamic torque is used as input in the transmission chain model, and the operating speed of the simulator is output. Since the simulator's moment of inertia is much smaller than that of the actual wind turbine, in order to obtain the same operating dynamics as the actual wind turbine, the input aerodynamic torque needs to be compensated so that the speed output by the simulator's transmission chain remains consistent with that of the actual wind turbine.

[0128] Step 2: Solve the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator, specifically:

[0129] Step 2-1, determine the transfer function of the wind turbine simulator transmission system:

[0130]

[0131] Among them, α d represents the filter parameters, J s To simulate the moment of inertia, J t is the actual moment of inertia, k0 represents the order of communication delay, k0 = 1, 2, 3…;

[0132] Step 2-2, determine the characteristic equation of the transfer function:

[0133]

[0134] It has k0+1 poles in the complex plane distributed at:

[0135]

[0136] Let z = re jθ ,r∈R,θ∈[0,2π], perform polar coordinate transformation, and substitute it into the above formula to obtain:

[0137]

[0138] is equivalent to:

[0139]

[0140] |z|<1 is equivalent to |r|<1, and the necessary and sufficient conditions for the stability of the wind turbine simulator transmission system with system delay using the equivalent k0+1 order filter are obtained: All real solutions of the equation system (10) |r|<1;

[0141] Let the function To find out whether the real number solution of the equation when y(r)=0 is in the interval [-1,1], take the derivative of y(r) and get:

[0142]

[0143] Let y′(r)=0, and we get that the equation has only one pole 0. In the interval [-1,1], the monotonic characteristics of the above equation are as follows:

[0144] When r>0, the original function is monotonically increasing;

[0145] When r<0, and k0 is an odd number, the equation is monotonically decreasing;

[0146] When r>0, if k0 is an even number, the equation is monotonically increasing.

[0147] like Figure 2 As shown;

[0148] The simulator system is stable and all solutions in the complex plane satisfy |r|<1.

[0149] get:

[0150]

[0151] Combined with the system stability condition, we get:

[0152]

[0153] Step 2-3: According to the symmetric characteristics of the original function, the value of the filter coefficient is related to the odd and even value of k0, thereby determining the filter parameter α of the wind turbine simulator d :

[0154]

[0155] In this embodiment, k0 is 3, and the k0+1-order filter parameter α is obtained under the condition of system stability. d Selection rules:

[0156]

[0157] Since the experiment uses a wind turbine simulator with 100 times the moment of inertia, the filter parameter is 0.98<α d <1.

[0158] Step 3: Determine the torque deviation component of the wind turbine simulator transmission system caused by system delay, specifically:

[0159] Step 3-1: The transfer function H″ of the wind turbine simulator transmission system imp_wts (z) Perform inverse z transformation to obtain the time domain response expression of the simplified transmission model of the wind turbine simulator using the k0+1 order filter:

[0160]

[0161] Where a′ wts (k) is the output acceleration of the transmission chain, a wt (k), a′ d (k) are the response components of the output acceleration, where:

[0162]

[0163] It can be seen that the existing wind turbine simulator still has a new deviation component a′ compared with the actual wind turbine d , causing abnormal speed fluctuations in the simulator.

[0164] However, since the system delay occurs in the feedback loop of the transmission chain, it is necessary to further analyze the specific factors that cause abnormal speed fluctuations; therefore, the transmission chain feedback loop expression of the wind turbine simulator is analyzed:

[0165]

[0166] It can be seen that the deviation of the torque output in its feedback loop is related to both the communication time lag and the simulation multiple;

[0167] Step 3-2: Perform an inverse z transform on the transmission chain feedback loop of step 3-1 to obtain the time domain expression of the feedback loop of the wind turbine simulator, thereby determining the torque deviation component caused by the system delay:

[0168]

[0169] Among them, f2(k) is the torque deviation component between the feedback loop of the wind turbine simulator model and the actual wind turbine. The torque deviation is expressed as acceleration r(k), that is, the speed acceleration of the simulator. As an input, the simulator will experience abnormal speed fluctuations when simulating the mechanical dynamics of a wind turbine simulator with a large moment of inertia.

[0170] Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator, specifically:

[0171] A torque deviation suppressor Z(k) is constructed at the driving torque input end of the wind turbine simulator system. In order to make the wind turbine simulator with the torque deviation suppressor have the same speed dynamics as the actual wind turbine, the transmission chains of the two need to have the same topological structure model, which are as follows:

[0172] H1(k)=1 / J t

[0173] H2(k)=Z(k)·h(k)

[0174]

[0175] Among them, H1(k) is the actual wind turbine transmission chain model, and H2(k) is the wind turbine simulator transmission chain model using the feedforward torque bias suppression strategy;

[0176] Let H1(k)=H2(k), we get:

[0177]

[0178] In order to make the system respond as quickly as possible, the poles of the system are configured at the origin of the z plane, and the filter coefficient α of the high-order filter is obtained. d Take the best:

[0179] Then the filter parameter α d The optimal value of α d opt for:

[0180]

[0181] That is, the filter coefficient α d opt =0.99, after applying this optimal value:

[0182]

[0183] At this time, the poles of the wind turbine simulator model considering the system delay are all located at the origin, and its transfer function is consistent with the transfer function of the actual wind turbine system. The wind turbine simulator model after the inertia compensation method of the invention is obtained as follows: Figure 3 shown.

[0184] In order to verify the effectiveness of the method for improving the simulation multiple of the moment of inertia of a wind turbine simulator based on feedforward deviation suppression torque compensation of the present invention, an experimental verification is carried out on a constructed wind turbine dynamic model experimental platform. The experimental platform structure is as follows: Figure 4 As shown in the figure, the wind turbine dynamic model experimental platform includes an asynchronous motor-permanent magnet generator towing platform, a motor drive device based on a frequency converter, and a permanent magnet generator converter. The system can simulate the dynamic characteristics of a single wind turbine, and based on the FAST software, by calling the aerodynamic loads calculated by it, it can accurately simulate the aerodynamic-elastic coupling characteristics of the wind turbine.

[0185] Set the simulation multiple to 100, i.e. Jt is 72kgm 2 , at this moment the filter parameter α d =0.99, the input wind speed is turbulent wind. Figure 5It can be seen that when simulating the speed dynamics of a wind turbine with 100 times the rotational inertia, the output speed obtained by testing with the existing inertia compensation method showed significant abnormal speed fluctuations.

[0186] The output speed obtained by testing the method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression of the present invention is as follows: Figure 6 As shown, it is possible to maintain the same dynamics as the simulation calculation speed and to match the simulation speed well, and to simulate the mechanical dynamics of a wind turbine with a rotational inertia one hundred times greater than its own, thus achieving the simulation of the mechanical dynamics of a megawatt-class wind turbine. The wind turbine simulator system using the inertia compensation method of the invention can not only ensure stability, but also suppress the influence of the torque deviation component, so that the simulator system no longer has abnormal speed fluctuations when simulating a wind turbine with a large rotational inertia.

[0187] In summary, the method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression proposed in the present invention utilizes the advance scaling torque component of the feedforward torque deviation suppressor to eliminate the unbalanced torque generated in the torque compensation loop, which greatly facilitates the use of existing experimental platforms to accurately simulate the slow mechanical dynamics of an actual wind turbine with a hundred times its own moment of inertia.

Claims

1. A method for increasing the moment of inertia of a wind turbine simulator based on feedforward deviation suppression, characterized in that: The following steps are involved: Step 1: Construct a discrete mathematical model of a wind turbine simulator including system delay: Step 1-1: Build a pneumatic model: T a =0.5ρπR 2 v 3 C p (l) / h λ=ωR / v Where ρ is the air density, R is the radius of the wind wheel, v is the wind speed, C p (λ) represents the wind energy utilization coefficient, T a represents the aerodynamic torque input to the simulator system, ω represents the angular velocity of the wind wheel, and λ represents the tip speed ratio; Step 1-2: Build the transmission chain model: τ=k0·T Where Ts is the output torque of the wind turbine simulator, J s To simulate the moment of inertia, J t is the actual moment of inertia, is the simulator speed acceleration, τ represents the communication time lag of the wind turbine simulator, T represents the control period of the wind turbine simulator, k0 represents the order of the communication time lag, k0=1,2,3…, N(z) is the k0+1 order filter in the transmission chain, α d represents the k0+1 order filter parameters in the wind turbine simulator; Step 2: Solve the characteristic equation based on the discrete mathematical model of the wind turbine simulator to determine the filter parameters of the wind turbine simulator: Step 2-1, determine the transfer function of the wind turbine simulator transmission system: Among them, J s To simulate the moment of inertia, J t is the actual moment of inertia, k0 represents the order of communication delay, k0 = 1, 2, 3…; Step 2-2, determine the characteristic equation of the transfer function: Step 2-3: Determine the filter parameter α of the wind turbine simulator d : Step 3, determining the torque deviation component of the wind turbine simulator transmission system caused by system delay; Step 4: construct a torque deviation inhibitor according to the determined torque deviation component, thereby increasing the moment of inertia of the wind turbine simulator.

2. The method for improving the moment of inertia of a wind turbine simulator based on feedforward deviation suppression according to claim 1 is characterized in that: The torque deviation component caused by the system delay in step 3 is specifically determined as follows: Step 3-1, determine the transmission chain feedback loop expression of the wind turbine simulator: Step 3-2: Perform an inverse z transform on the transmission chain feedback loop of step 3-1 to obtain the time domain expression of the feedback loop of the wind turbine simulator, thereby determining the torque deviation component caused by the system delay: Among them, f2(k) is the torque deviation component between the feedback loop of the wind turbine simulator model and the actual wind turbine. The input of the torque deviation component is the acceleration r(k), that is, the speed acceleration of the simulator.

3. The method for increasing the moment of inertia of a wind turbine simulator based on feedforward deviation suppression according to claim 1 is characterized in that: The construction of the torque deviation inhibitor in step 4 is specifically as follows: A torque deviation suppressor Z(k) is constructed at the driving torque input end of the wind turbine simulator system:

4. The method for increasing the moment of inertia of a wind turbine simulator based on feedforward deviation suppression according to claim 1 or 3, characterized in that: The filter parameter α d The optimal value of α d opt for:

5. A wind turbine simulator rotation inertia enhancement system based on feedforward deviation suppression based on the method of claim 1, characterized in that: Includes the following modules: Model building module: used to build a discrete mathematical model of a wind turbine simulator including system delay; Parameter determination module: used to determine the filter parameters of the wind turbine simulator; Torque deviation component module: used to determine the torque deviation component of the wind turbine simulator transmission system caused by system delay; Torque deviation suppression module: used to construct a torque deviation suppressor according to the determined torque deviation component, so as to increase the moment of inertia multiple of the wind turbine simulator.

6. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer storable medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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