Wind power system control method and system based on wind wheel virtual inertia

Abstract

The invention discloses a wind power system control method and system based on the virtual inertia of a wind wheel, and the method comprises the steps: obtaining equipment parameters of a wind turbine generator, and calculating the rotational inertia according to the equipment parameters; according to the rotational inertia and the energy capture power of the wind turbine generator, constructing an energy transfer relation of the wind turbine generator; constructing an equivalent inertia equation according to the rotational inertia and the energy transfer relation of the wind turbine generator; according to the equivalent inertia equation, determining equivalent inertia levels of the wind turbine generator in different working condition modes; and according to the equivalent inertia level, calculating a virtual inertia time constant under the corresponding working condition, and according to the virtual inertia time constant, controlling the wind power system. According to the method, different working condition modes of the system are comprehensively considered, and the calculation mode of the corresponding virtual inertia is obtained, so that the problem of inaccurate virtual inertia adjustment caused by different working conditions when the wind turbine generator provides inertia support is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power systems, and in particular relates to a wind power system control method and system based on wind rotor virtual inertia. Background Art

[0002] In traditional power systems, the mechanical inertia provided by large synchronous generators is critical to the stable operation of the power system. When the grid experiences frequency fluctuations, the inertia of the generators can help buffer these fluctuations until the regulation mechanism can respond. However, as more renewable energy sources (such as wind and solar) are connected to the grid, traditional synchronous generators are gradually reduced, and these renewable energy devices do not usually have the same mechanical inertia.

[0003] To address this issue, modern power electronic devices (such as inverters) can be programmed to simulate the inertial behavior of traditional generators, the so-called "virtual inertia". In this way, the power grid can maintain better frequency stability even with a high penetration of renewable energy. However, existing technical means have not fully considered the system's adaptive adjustment of different virtual inertia control strategies under different operating conditions. Summary of the invention

[0004] In response to the shortcomings of the prior art, the present application provides a wind power system control method and system based on the virtual inertia of the wind rotor. By comprehensively considering the different operating modes of the system, a corresponding method for calculating the virtual inertia is obtained, thereby solving the problem of inaccurate virtual inertia adjustment caused by different operating conditions when the wind turbine provides inertia support.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a wind power system control method based on wind rotor virtual inertia, comprising:

[0006] Obtain and calculate the moment of inertia based on the equipment parameters of the wind turbine;

[0007] constructing an energy transfer relationship of the wind turbine generator set according to the moment of inertia and the energy capture power of the wind turbine generator set;

[0008] Constructing an equivalent inertia equation according to the moment of inertia and the energy transfer relationship of the wind turbine generator set;

[0009] Determining the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation;

[0010] According to the equivalent inertia level, a virtual inertia time constant under a corresponding working condition is calculated, and according to the virtual inertia time constant, the wind power system is controlled.

[0011] Compared with the prior art, the embodiments of the present application have the following beneficial effects: by calculating the rotational inertia of the wind turbine and establishing an energy transfer relationship, it helps to optimize the energy conversion process and ensure that the wind turbine can work in the most efficient manner, thereby improving the overall efficiency of the system. Constructing an equivalent inertia equation helps to formulate a more reasonable inertia support strategy, analyze the equivalent inertia expression under different operating modes, allow the control system to be optimized for specific operating conditions, calculate the virtual inertia time constant, and adjust the system control accordingly. It can dynamically adjust its response speed according to the current operating conditions, achieve more precise frequency regulation, and improve the responsiveness and flexibility of the control system.

[0012] In some embodiments of the first aspect of the present application, the obtaining and calculating the moment of inertia according to the equipment parameters of the wind turbine generator set includes:

[0013] Obtain equipment parameters of wind turbine blades and hubs in wind turbines;

[0014] According to the equipment parameters, the moment of inertia is calculated, wherein the calculation formula is as follows:

[0015]

[0016]

[0017] Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wt Represents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

[0018] The above embodiment has the following beneficial effects: accurately calculating the moment of inertia through equipment parameters helps to accurately control the dynamic behavior of the wind turbine, and also provides a basis for establishing subsequent energy transfer relations and equivalent inertia expressions.

[0019] In some embodiments of the first aspect of the present application, constructing an energy transfer relationship of the wind turbine generator set according to the moment of inertia and the energy capture power of the wind turbine generator set includes:

[0020] Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of

[0021]

[0022]

[0023]

[0024] Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the radius of the wind rotor, v is the wind speed, ω is the angular velocity of the wind rotor, Cp is the wind energy utilization coefficient, ΔP ω is the change in power captured by the wind turbine, and A and B are functions of the tip speed ratio λ and the pitch angle β.

[0025] The above-mentioned embodiments have the following beneficial effects: by constructing an energy transfer relationship, one can better understand how wind turbines absorb energy from wind and convert it into electrical energy, which helps to optimize the energy conversion process and ensure that wind turbines can operate in the most efficient manner, thereby improving the overall efficiency of the system.

[0026] In some embodiments of the first aspect of the present application, constructing an equivalent inertia equation according to the moment of inertia and the energy transfer relationship of the wind turbine generator set includes:

[0027] According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows:

[0028] Construct the rotation equation:

[0029] When P ω When changes occur, there are: Where ω0 is the initial speed;

[0030] Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor;

[0031] According to the above formula, the expression of equivalent inertia is obtained:

[0032] The above embodiment has the following beneficial effects: the equivalent inertia equation provides a method to quantify the behavior of a wind turbine when providing inertia support. Through such quantification, the contribution of inertia can be taken into account when designing a controller, making the wind turbine closer to the behavior mode of a traditional generator.

[0033] In some embodiments of the first aspect of the present application, determining the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation includes:

[0034] Constructing virtual inertia in maximum power point tracking mode The expression is as follows:

[0035]

[0036] in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode;

[0037] Constructing virtual inertia in overspeed load reduction mode The expression is as follows:

[0038]

[0039] The above-mentioned embodiments have the following beneficial effects: analyzing the equivalent inertia under different operating modes allows the control system to be optimized for specific operating conditions. For example, in the maximum power point tracking mode (MPPT), the energy capture efficiency can be maximized, while in the overspeed load reduction mode, the equipment can be protected from overload damage.

[0040] In some embodiments of the first aspect of the present application, the calculating, according to the equivalent inertia level, a virtual inertia time constant under a corresponding working condition, and controlling the wind power system according to the virtual inertia time constant, includes:

[0041] When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows: Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency;

[0042] According to the wind wheel motion equation and the frequency response equation, it is calculated that:

[0043]

[0044] And get the virtual inertia time constant H v The expression is:

[0045] According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained;

[0046] The current wind power system is adjusted according to the virtual inertia time constant.

[0047] The above embodiment has the following beneficial effects: by calculating the virtual inertia time constant, the system can dynamically adjust its response speed according to the current working conditions. This dynamic adjustment helps to improve the flexibility and adaptability of the system and ensure that stable output can be maintained even when the grid conditions change.

[0048] In a second aspect, the embodiment of the present application further provides a wind power system control system based on wind rotor virtual inertia, including: a rotational inertia calculation module, an energy relationship construction module, an equivalent inertia construction module, an analysis module and an adjustment module;

[0049] Wherein, the rotational inertia calculation module is used to obtain and calculate the rotational inertia according to the equipment parameters of the wind turbine generator set;

[0050] The energy relationship building module is used to build an energy transfer relationship of the wind turbine generator set according to the rotational inertia and the energy capture power of the wind turbine generator set;

[0051] The equivalent inertia construction module is used to construct an equivalent inertia equation according to the rotational inertia and the energy transfer relationship of the wind turbine generator set;

[0052] The analysis module is used to determine the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation;

[0053] The adjustment module is used to calculate a virtual inertia time constant under a corresponding working condition according to the equivalent inertia level, and control the wind power system according to the virtual inertia time constant.

[0054] In some embodiments of the second aspect of the present application, the moment of inertia calculation module includes: a collection unit and a first calculation unit;

[0055] The acquisition unit is used to obtain equipment parameters of wind turbine blades and hubs in the wind turbine set;

[0056] The first calculation unit is used to calculate the moment of inertia according to the device parameters, wherein the calculation formula is as follows:

[0057]

[0058]

[0059] Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wtRepresents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

[0060] In some embodiments of the second aspect of the present application, the energy relationship building module includes:

[0061] Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of

[0062]

[0063] Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the radius of the wind rotor, v is the wind speed, ω is the angular velocity of the wind rotor, C p is the wind energy utilization coefficient, ΔP ω is the change in power captured by the wind turbine, and A and B are functions of the tip speed ratio λ and the pitch angle β.

[0064] In some embodiments of the second aspect of the present application, the equivalent inertia building block includes:

[0065] According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows:

[0066] Construct the rotation equation:

[0067] When P ω When changes occur, there are: Where ω0 is the initial speed;

[0068] Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor;

[0069] According to the above formula, the expression of equivalent inertia is obtained:

[0070] In some embodiments of the second aspect of the present application, the analysis module includes: a first analysis module and a second analysis module;

[0071] The first analysis module is used to construct the virtual inertia in the maximum power point tracking mode The expression of is constructed as follows:

[0072]

[0073] in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode;

[0074] The second analysis module is used to construct the virtual inertia in the overspeed load reduction mode The expression of is constructed as follows:

[0075] In some embodiments of the second aspect of the present application, the adjustment module includes: a virtual inertia calculation unit and a control unit;

[0076] The virtual inertia calculation unit is used to calculate the virtual inertia time constant of the wind turbine under the current working condition, wherein the calculation method is as follows:

[0077] When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows: Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency;

[0078] According to the wind wheel motion equation and the frequency response equation, it is calculated that:

[0079]

[0080] And get the virtual inertia time constant H v The expression is:

[0081] According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained;

[0082] The control unit is used to adjust the current wind power system according to the virtual inertia time constant.

[0083] Compared with the prior art, the above embodiments have the following beneficial effects: by calculating the rotational inertia of the wind turbine and establishing an energy transfer relationship, it helps to optimize the energy conversion process and ensure that the wind turbine can work in the most efficient manner, thereby improving the overall efficiency of the system; constructing an equivalent inertia equation helps to formulate a more reasonable inertia support strategy, analyze the equivalent inertia expression under different operating modes, allow the control system to be optimized for specific operating conditions, calculate the virtual inertia time constant, and adjust the system control accordingly, and can dynamically adjust its response speed according to the current operating conditions, achieve more precise frequency regulation, and improve the responsiveness and flexibility of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 : A flow chart of a wind power system control method based on wind rotor virtual inertia provided in some embodiments of the present invention.

[0085] Figure 2 : A structural schematic diagram of a wind power system control system based on wind rotor virtual inertia provided in some embodiments of the present invention.

[0086] Figure 3 : A diagram of the main structural parameters of a wind turbine generator set provided in some embodiments of the present invention.

[0087] Figure 4 : A mapping diagram of wind energy utilization coefficient and blade tip speed ratio provided in some embodiments of the present invention. DETAILED DESCRIPTION

[0088] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0089] Embodiment 1:

[0090] Please refer to Figure 1 , a wind power system control method based on wind rotor virtual inertia provided by an embodiment of the present invention, comprising steps S1 to S5:

[0091] Step S1: Obtain and calculate the moment of inertia according to the equipment parameters of the wind turbine generator set;

[0092] In some embodiments of the present application, step S1 can be implemented by the following preferred implementations:

[0093] S11: Obtain equipment parameters of wind turbine blades and hubs in the wind turbine generator set;

[0094] S12: Calculate the moment of inertia according to the device parameters, wherein the calculation formula is as follows:

[0095]

[0096]

[0097] Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wt Represents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

[0098] For example, Figure 3 The main structural parameters of a wind turbine generator set are shown in FIG.

[0099] M blade =5530*3=16590kg, M rotor =13850kg, R blade =37.3m,

[0100] R rotor =3.73 / 2=1.865m, Ω0=1.8117rad / s; calculated =T J =16.88s.

[0101] In this embodiment, accurately calculating the moment of inertia through equipment parameters helps to accurately control the dynamic behavior of the wind turbine generator set, and also provides a basis for establishing subsequent energy transfer relations and equivalent inertia expressions.

[0102] Step S2: constructing an energy transfer relationship of the wind turbine generator set according to the moment of inertia and the energy capture power of the wind turbine generator set;

[0103] In some embodiments of the present application, step S2 can be implemented by the following preferred implementations:

[0104] Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of

[0105]

[0106]

[0107]

[0108] Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the rotor radius, v is the wind speed, ω is the rotor angular velocity, and Cp is the wind energy utilization coefficient, which is related to the pitch angle β and the blade tip speed ratio λ of the generator. According to the Betz theory, its maximum value is 0.593. Under different pitch angles, the mapping diagram of wind energy utilization coefficient Cp and blade tip speed ratio λ is as follows: Figure 4 As shown, ΔP ω is the change in power captured by the wind turbine. A and B are functions of the tip speed ratio λ and the pitch angle β, which can be calculated by the following formula:

[0109]

[0110]

[0111] In this embodiment, by constructing an energy transfer relationship, we can better understand how wind turbines absorb energy from wind and convert it into electrical energy, which helps to optimize the energy conversion process and ensure that wind turbines can work in the most efficient manner, thereby improving the overall efficiency of the system.

[0112] Step S3: constructing an equivalent inertia equation according to the rotational inertia and the energy transfer relationship of the wind turbine generator set;

[0113] In some embodiments of the present application, step S3 can be implemented by the following preferred implementations:

[0114] According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows:

[0115] Construct the rotation equation:

[0116] When P ω When changes occur, there are: Where ω0 is the initial speed;

[0117] Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor;

[0118] According to the above formula, the expression of equivalent inertia is obtained:

[0119] In this embodiment, the equivalent inertia equation provides a method to quantify the behavior of the wind turbine when providing inertia support. Through such quantification, the contribution of inertia can be taken into account when designing the controller, making the wind turbine closer to the behavior mode of a traditional generator.

[0120] Step S4: determining the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation;

[0121] In some embodiments of the present application, step S4 can be implemented by the following preferred implementations:

[0122] S41: Constructing virtual inertia in maximum power point tracking mode The expression is as follows:

[0123]

[0124] in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode;

[0125] S42: Constructing virtual inertia in overspeed load reduction mode The expression is as follows:

[0126]

[0127] For example: In the maximum power point tracking mode (MPPT) mode, when λ = λ opt When the wind turbine does not provide inertia support, if the additional inertia support control causes the wind turbine to start to reduce the speed, then T in the expression J ω decreases as the speed decreases; It starts to increase from 0, which is related to the rate of change of the wind rotor speed and the value of the variable A(λ). Obviously, there is a moment t=t p , corresponding to the fan speed ω p Make =0. If the wind speed continues to decrease, the energy support provided by the release of the wind rotor inertia will be completely covered by the wind energy capture loss, which is not worth the loss. It can be seen that in the MPPT mode, when the wind turbine rotor provides inertia support, the speed should be reduced to ω p Stop inertia support before the frequency drops. At the same time, consider restoring the rotor speed in time to reduce wind energy capture losses while avoiding secondary frequency drops.

[0128] In the overspeed load reduction mode, the speed of the wind wheel is greater than the speed in the MPPT mode, so that λ>λ optWhen the wind turbine senses that the system frequency is decreasing, it reduces the tip speed ratio λ by reducing the rotor speed, thereby increasing the wind energy utilization coefficient Cp, and increasing the wind turbine capture power. Considering that the decrease in rotor speed will release some kinetic energy, before reaching the maximum power operating point, as the speed ω decreases, Continue to increase until ω=ω opt .

[0129] In this embodiment, the equivalent inertia under different operating modes is analyzed, allowing the control system to be optimized for specific operating conditions. For example, in the maximum power point tracking mode (MPPT), the energy capture efficiency can be maximized, while in the overspeed load reduction mode, the equipment can be protected from overload damage.

[0130] Step S5: Calculate a virtual inertia time constant under a corresponding working condition according to the equivalent inertia level, and control the wind power system according to the virtual inertia time constant.

[0131] In some embodiments of the present application, step S5 can be implemented by the following preferred implementations:

[0132] S51: When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows:

[0133] Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency;

[0134] According to the wind wheel motion equation and the frequency response equation, it is calculated that:

[0135]

[0136] And get the virtual inertia time constant H v The expression is:

[0137] According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained;

[0138] S52: Adjusting the current wind power system according to the virtual inertia time constant.

[0139] For example: Figure 3 The main structural parameters of a wind turbine generator set shown in the figure are as follows:

[0140] Take T J =18s, dω / dt max = ±0.2pu / s,ω opt =1.8071rad / s, when the frequency change rate df / dt is -0.1Hz / s, the wind wheel speed changes from the initial value 1.1ω opt Down to 0.95ω opt When H v The value of is 2.6147s, where When df / dt=-0.1Hz / s,ω changes from 1.0ω opt Down to 0.95ω opt When H v The value of is 1.2089s, where

[0141] It can be seen that the time constant of virtual inertia control of wind turbines mainly depends on the inertia time constant T of the wind rotor. J , wind rotor speed ω, and the ratio of speed change rate dω / dt and frequency change rate df / dt. When the maximum value of the wind turbine speed change rate dω / dtmax is used as the inertia support index, the speed will drop excessively at low frequency change rate and the wind rotor virtual inertia time constant will be too large. Therefore, considering the change of system frequency, dω / df can be defined as the speed-frequency sensitivity index of the wind turbine.

[0142] In this embodiment, by calculating the virtual inertia time constant, the system can dynamically adjust its response speed according to the current working conditions. This dynamic adjustment helps to improve the flexibility and adaptability of the system and ensure that stable output can be maintained even when the grid conditions change.

[0143] In summary, compared with the prior art, the embodiments of the present application have the following beneficial effects: by calculating the rotational inertia of the wind turbine and establishing an energy transfer relationship, it helps to optimize the energy conversion process and ensure that the wind turbine can work in the most efficient manner, thereby improving the overall efficiency of the system. Constructing an equivalent inertia equation helps to formulate a more reasonable inertia support strategy, analyze the equivalent inertia expression under different operating modes, allow the control system to be optimized for specific operating conditions, calculate the virtual inertia time constant, and adjust the system control accordingly. It can dynamically adjust its response speed according to the current operating conditions, achieve more precise frequency regulation, and improve the responsiveness and flexibility of the control system.

[0144] Embodiment 2:

[0145] Please refer to Figure 2Based on the same inventive concept, an embodiment of the present invention discloses a wind power system control system based on wind wheel virtual inertia, including: a rotational inertia calculation module M1, an energy relationship construction module M2, an equivalent inertia construction module M3, an analysis module M4 and an adjustment module M5.

[0146] The moment of inertia calculation module M1 is used to obtain and calculate the moment of inertia according to the equipment parameters of the wind turbine generator set;

[0147] The moment of inertia calculation module M1 includes: a collection unit and a first calculation unit;

[0148] The acquisition unit is used to obtain equipment parameters of wind turbine blades and hubs in the wind turbine set;

[0149] The first calculation unit is used to calculate the moment of inertia according to the device parameters, wherein the calculation formula is as follows:

[0150]

[0151]

[0152] Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wt Represents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

[0153] The moment of inertia calculation module M1 of this embodiment accurately calculates the moment of inertia through equipment parameters, which helps to accurately control the dynamic behavior of the wind turbine and also provides a basis for establishing subsequent energy transfer relations and equivalent inertia expressions.

[0154] The energy relationship building module M2 is used to build an energy transfer relationship of the wind turbine generator set according to the rotational inertia and the energy capture power of the wind turbine generator set;

[0155] The energy relationship building module M2 includes:

[0156] Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of

[0157]

[0158]

[0159]

[0160] Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the radius of the wind rotor, v is the wind speed, ω is the angular velocity of the wind rotor, C p is the wind energy utilization coefficient, ΔP ω is the change in power captured by the wind turbine, and A and B are functions of the tip speed ratio λ and the pitch angle β.

[0161] The energy relationship construction module M2 of this embodiment can better understand how wind turbines absorb energy from wind and convert it into electrical energy by constructing energy transfer relationships, which helps to optimize the energy conversion process and ensure that wind turbines can work in the most efficient manner, thereby improving the overall efficiency of the system.

[0162] The equivalent inertia construction module M3 is used to construct an equivalent inertia equation according to the rotational inertia and the energy transfer relationship of the wind turbine generator set;

[0163] The equivalent inertia building block M3 includes:

[0164] According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows:

[0165] Construct the rotation equation:

[0166] When P ω When changes occur, there are: Where ω0 is the initial speed;

[0167] Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor;

[0168] According to the above formula, the expression of equivalent inertia is obtained:

[0169] The equivalent inertia construction module M3 of this embodiment provides a method for quantifying the behavior of the wind turbine when providing inertia support by constructing an equivalent inertia equation. Through such quantification, the contribution of inertia can be taken into account when designing the controller, making the wind turbine closer to the behavior mode of a traditional generator.

[0170] The analysis module M4 is used to determine the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation;

[0171] The analysis module M4 includes: a first analysis module and a second analysis module;

[0172] The first analysis module is used to construct the virtual inertia in the maximum power point tracking mode The expression of is constructed as follows:

[0173]

[0174] in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode;

[0175] The second analysis module is used to construct the virtual inertia in the overspeed load reduction mode The expression of is constructed as follows:

[0176] The analysis module M4 of this embodiment allows the control system to be optimized for specific operating conditions by analyzing the equivalent inertia under different operating modes. For example, in the maximum power point tracking mode (MPPT), the energy capture efficiency can be maximized, while in the overspeed load reduction mode, the equipment can be protected from overload damage.

[0177] The adjustment module M5 is used to calculate the virtual inertia time constant under the corresponding working condition according to the equivalent inertia level, and control the wind power system according to the virtual inertia time constant;

[0178] The adjustment module M5 includes: a virtual inertia calculation unit and a control unit;

[0179] The virtual inertia calculation unit is used to calculate the virtual inertia time constant of the wind turbine under the current working condition, wherein the calculation method is as follows:

[0180] When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows: Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency;

[0181] According to the wind wheel motion equation and the frequency response equation, it is calculated that:

[0182]

[0183] And get the virtual inertia time constant H v The expression is:

[0184] According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained;

[0185] The control unit is used to adjust the current wind power system according to the virtual inertia time constant.

[0186] The adjustment module M5 of this embodiment calculates the virtual inertia time constant so that the system can dynamically adjust its response speed according to the current working conditions. This dynamic adjustment helps to improve the flexibility and adaptability of the system and ensure that stable output can be maintained even when the grid conditions change.

[0187] In summary, compared with the prior art, the embodiments of the present application have the following beneficial effects: by calculating the rotational inertia of the wind turbine and establishing an energy transfer relationship, it helps to optimize the energy conversion process and ensure that the wind turbine can work in the most efficient manner, thereby improving the overall efficiency of the system. Constructing an equivalent inertia equation helps to formulate a more reasonable inertia support strategy, analyze the equivalent inertia expression under different operating modes, allow the control system to be optimized for specific operating conditions, calculate the virtual inertia time constant, and adjust the system control accordingly. It can dynamically adjust its response speed according to the current operating conditions, achieve more precise frequency regulation, and improve the responsiveness and flexibility of the control system.

[0188] The specific working process of each module described above can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here. The module division is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules can be combined or integrated into another system.

[0189] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wind power system control method based on wind rotor virtual inertia, characterized in that: include: Obtain and calculate the moment of inertia based on the equipment parameters of the wind turbine; constructing an energy transfer relationship of the wind turbine generator set according to the moment of inertia and the energy capture power of the wind turbine generator set; Constructing an equivalent inertia equation according to the moment of inertia and the energy transfer relationship of the wind turbine generator set; Determining the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation; According to the equivalent inertia level, a virtual inertia time constant under a corresponding working condition is calculated, and according to the virtual inertia time constant, the wind power system is controlled.

2. A wind power system control method based on wind rotor virtual inertia according to claim 1, characterized in that: The step of obtaining and calculating the moment of inertia according to the equipment parameters of the wind turbine generator set includes: Obtain equipment parameters of wind turbine blades and hubs in wind turbines; According to the equipment parameters, the moment of inertia is calculated, wherein the calculation formula is as follows: Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wt Represents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

3. A wind power system control method based on wind rotor virtual inertia according to claim 2, characterized in that: The step of constructing an energy transfer relationship of the wind turbine generator set according to the moment of inertia and the energy capture power of the wind turbine generator set comprises: Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the radius of the wind rotor, v is the wind speed, ω is the angular velocity of the wind rotor, C p is the wind energy utilization coefficient, ΔP ω is the change in power captured by the wind turbine, and A and B are functions of the tip speed ratio λ and the pitch angle β.

4. A wind power system control method based on wind rotor virtual inertia according to claim 3, characterized in that: The constructing of an equivalent inertia equation according to the moment of inertia and the energy transfer relationship of the wind turbine generator set comprises: According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows: Construct the rotation equation: When P ω When changes occur, there are: Where ω0 is the initial speed; Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor; According to the above formula, the expression of equivalent inertia is obtained:

5. A wind power system control method based on wind rotor virtual inertia according to claim 4, characterized in that: Determining the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation includes: Constructing virtual inertia in maximum power point tracking mode The expression is as follows: in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode; Constructing virtual inertia in overspeed load reduction mode The expression is as follows:

6. A wind power system control method based on wind rotor virtual inertia according to claim 5, characterized in that: The step of calculating a virtual inertia time constant under a corresponding working condition according to the equivalent inertia level, and controlling a wind power system according to the virtual inertia time constant includes: When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows: Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency; According to the wind wheel motion equation and the frequency response equation, it is calculated that: And get the virtual inertia time constant H v The expression is: According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained; The current wind power system is adjusted according to the virtual inertia time constant.

7. A wind power system control system based on wind rotor virtual inertia, characterized in that: include: Rotational inertia calculation module, energy relationship building module, equivalent inertia building module, analysis module and adjustment module; Wherein, the rotational inertia calculation module is used to obtain and calculate the rotational inertia according to the equipment parameters of the wind turbine generator set; The energy relationship building module is used to build an energy transfer relationship of the wind turbine generator set according to the rotational inertia and the energy capture power of the wind turbine generator set; The equivalent inertia construction module is used to construct an equivalent inertia equation according to the rotational inertia and the energy transfer relationship of the wind turbine generator set; The analysis module is used to determine the equivalent inertia level of the wind turbine generator set under different operating modes according to the equivalent inertia equation; The adjustment module is used to calculate a virtual inertia time constant under a corresponding working condition according to the equivalent inertia level, and control the wind power system according to the virtual inertia time constant.

8. A wind power system control system based on wind rotor virtual inertia as claimed in claim 7, characterized in that: The moment of inertia calculation module includes: a collection unit and a first calculation unit; The acquisition unit is used to obtain equipment parameters of wind turbine blades and hubs in the wind turbine set; The first calculation unit is used to calculate the moment of inertia according to the device parameters, wherein the calculation formula is as follows: I wt =J blade +J rotor ; Among them, J blade and J rotor are the moments of inertia of the wind turbine blades and hub, M blade and M rotor are the masses of the wind turbine blades and hub, R blade and R rotor are the radii of the wind turbine blades and hub, J wt Represents the moment of inertia of the wind turbine rotor, T J is the inertia time constant of the wind turbine rotor, ω0 is the initial angular velocity of the wind rotor, S base is the rated power of the wind turbine.

9. A wind power system control system based on wind rotor virtual inertia as claimed in claim 8, characterized in that: The energy relationship building module includes: Building energy capture power P ω The energy transfer relationship of the wind turbine is obtained by using the expression of Among them, P B is the rated output power of the fan, P ω is the per-unit value of the power captured by the wind turbine, ρ is the air density, R is the radius of the wind rotor, v is the wind speed, ω is the angular velocity of the wind rotor, C p is the wind energy utilization coefficient, ΔP ω is the change in power captured by the wind turbine, and A and B are functions of the tip speed ratio λ and the pitch angle β.

10. A wind power system control system based on wind rotor virtual inertia according to claim 9, characterized in that: The equivalent inertia building blocks include: According to the energy transfer relationship between the moment of inertia and the wind turbine generator set, an equivalent inertia equation is constructed, and the construction formula is as follows: Construct the rotation equation: When P ω When changes occur, there are: Where ω0 is the initial speed; Construct the wind rotor motion equation: Among them, H equ is the equivalent inertia of the wind turbine rotor; According to the above formula, the expression of equivalent inertia is obtained:

11. A wind power system control system based on wind rotor virtual inertia according to claim 10, characterized in that: The analysis module comprises: a first analysis module and a second analysis module; The first analysis module is used to construct the virtual inertia in the maximum power point tracking mode The expression of is constructed as follows: in, is the virtual inertia in the maximum power point tracking mode, λ opt is the tip speed ratio of the wind turbine in the maximum power point tracking mode; The second analysis module is used to construct the virtual inertia in the overspeed load reduction mode The expression of is constructed as follows:

12. A wind power system control system based on wind rotor virtual inertia according to claim 11, characterized in that: The adjustment module includes: a virtual inertia calculation unit and a control unit; The virtual inertia calculation unit is used to calculate the virtual inertia time constant of the wind turbine under the current working condition, wherein the calculation method is as follows: When the virtual inertia control link is added to the machine side, the frequency response equation is obtained as follows: Where P ref is the active power reference value of the grid-side converter; H v is the virtual inertia time constant, P es is the DC power output by the machine-side converter, and f is the system frequency; According to the wind wheel motion equation and the frequency response equation, it is calculated that: And get the virtual inertia time constant H v The expression is: According to the actual parameters of the wind turbine and the equivalent inertia expression under the current working mode, substitute the virtual inertia time constant H v The expression of virtual inertia time constant of wind turbine under current working condition is obtained; The control unit is used to adjust the current wind power system according to the virtual inertia time constant.

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