Stability maintaining method and device for virtual inertia control and primary frequency modulation and medium

Abstract

The invention discloses a stability maintaining method and device for virtual inertia control and primary frequency modulation and a medium, and the method comprises the steps: if a frequency deviation occurs in a power system where a wind turbine generator set is located, starting the wind turbine generator set when the frequency deviation is equal to a frequency lower limit, so as to reduce the frequency deviation; if the power system does not have the frequency deviation or the frequency deviation is reduced, converting the proportionality coefficient for adjusting the power output of the fan into the optimal proportionality coefficient; the working point of the wind turbine generator is kept on the maximum power point tracking curve by performing primary frequency adjustment on the wind turbine generator. According to the virtual inertia control and primary frequency modulation stability maintaining method and device and the medium, through timely adjustment of the proportionality coefficient and accurate primary frequency adjustment, it can be ensured that a wind turbine generator stably operates near the maximum power point, meanwhile, step changes of active power are reduced, and the stability of the wind turbine generator is improved. The problem that impact caused by active power step is difficult to avoid and effective stability maintenance is carried out on a power system can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine control, and in particular to a virtual inertia control and primary frequency modulation stabilization method, device and medium. Background Art

[0002] Doubly fed induction generator (DFIG) has become the main model of large wind farms. DFIG can flexibly adjust active power and reactive power through power electronic converters, track the maximum power point trajectory, improve wind energy utilization, and reduce harmonic pollution of wind power grid operation. With the construction and development of new power systems in various regions, the penetration rate of wind power will be further improved in the future. When doubly fed induction generators are connected to the grid, the stability of their feeders is directly related to the stability of the entire power system. Traditional feeder maintenance is to ensure the normal operation of power equipment through regular inspection and maintenance, and to establish a complete power grid event monitoring and prediction system to monitor each key node of the power grid in real time, timely discover potential fault hazards and conduct predictive analysis, and reduce the impact of equipment failures on feeder voltage stability.

[0003] However, in traditional feeders, due to the influence of small voltage fluctuations, voltage control equipment for feeders with large voltage fluctuations is often not equipped; and due to the characteristics of distributed power sources and charging piles, the influence of the grid access level, the limitations of voltage control equipment, the increase in system complexity and technical challenges and other factors, when the number of adjustable sources and loads connected to the grid increases rapidly, it is easy to cause large fluctuations in feeder voltage, making it difficult to ensure the stability of power system operation. Summary of the invention

[0004] The present invention provides a virtual inertia control and primary frequency modulation stabilization method, device and medium to solve the problem of difficult to avoid impact caused by active power step and effectively maintain stability of power system.

[0005] If a frequency deviation occurs in the power system where the wind turbine generator set is located, the frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit;

[0006] If the power system does not have a frequency deviation or after the frequency deviation is reduced, the proportional coefficient for adjusting the wind turbine power output is transformed into an optimal proportional coefficient; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine;

[0007] By performing a frequency adjustment on the wind turbine generator set, the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

[0008] In the present invention, the starting process of the wind turbine generator set itself is a smooth power output process, rather than a sudden, step-like power change. Therefore, starting the wind turbine generator set when the frequency deviation reaches the lower limit can gradually and smoothly increase the active power output of the power system, thereby avoiding the impact of the active power step change on the power system. In the case that the wind turbine generator set has no frequency deviation or the frequency deviation has been reduced, by adjusting the proportional coefficient to the optimal value, the output power of the wind turbine generator set can be optimized, so that it can be connected to the power system more smoothly, and the step change of active power can be reduced. This smooth power output helps to reduce the impact on the power system and improve the stability of the power system. The primary frequency adjustment can quickly respond to the frequency change of the power system. Therefore, the frequency of the power system is stabilized by adjusting the output power of the wind turbine generator set, which not only helps to maintain the stability of the power system, but also improves the anti-interference ability of the power system.

[0009] Compared with the prior art, the present invention can ensure the stable operation of the wind turbine near the maximum power point by timely adjusting the proportional coefficient and precise primary frequency adjustment, while reducing the step change of active power. Therefore, it can solve the problem of the impact caused by the active power step that is difficult to avoid and effectively maintain the stability of the power system.

[0010] As a preferred solution, if a frequency deviation occurs in the power system where the wind turbine generator set is located, the frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit, specifically:

[0011] If the frequency deviation occurs in the power system where the wind turbine generator set is located, a dynamic proportional coefficient is set in the controller of the wind turbine generator set according to the deviation between the input frequency and the set frequency, so that the output power of the wind turbine generator set changes linearly;

[0012] The frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the frequency lower limit.

[0013] This preferred solution sets a dynamic proportional coefficient according to the deviation between the input frequency and the set frequency, and can adjust the output power of the wind turbine in real time, so that it can quickly respond to the frequency deviation, thereby improving the response speed of the system; and the linear change of the output power helps to more accurately control the operating state of the wind turbine and reduce the system instability caused by the sudden change of the output power. When the frequency deviation is equal to the lower frequency limit, the wind turbine is started, and the frequency deviation is reduced by dynamically adjusting the output power, which helps to maintain the frequency stability of the power system.

[0014] As a preferred solution, the dynamic proportional coefficient is specifically:

[0015] Calculating the optimal proportional coefficient according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine generator set;

[0016] Calculating a maximum proportionality coefficient according to the wind speed and the rotor speed of the wind turbine generator set;

[0017] The weights of the optimal scale factor and the maximum scale factor are adjusted based on a dynamic factor to establish the dynamic scale factor.

[0018] This preferred solution can ensure that the wind turbine operates in the optimal state by considering the maximum wind energy utilization coefficient and the optimal tip speed ratio, thereby maximizing the capture and utilization of wind energy. The calculation and application of the optimal proportional coefficient helps to reduce energy waste and improve the power generation efficiency of the wind turbine. By adjusting the weights of the optimal proportional coefficient and the maximum proportional coefficient based on dynamic factors, the wind turbine can be adaptively adjusted according to changes in real-time wind speed and rotor speed; this dynamic adjustment strategy helps wind turbines maintain efficient and stable operation in complex and changeable wind energy environments, and improves their adaptability and flexibility to the environment.

[0019] As a preferred solution, if the power system does not have a frequency deviation or after the frequency deviation is reduced, the proportional coefficient for adjusting the wind turbine power output is transformed to an optimal proportional coefficient, specifically:

[0020] If the power system has no frequency deviation, the control proportional coefficient is transformed into the optimal proportional coefficient; wherein the proportional coefficient is used to adjust the wind turbine power output;

[0021] After the frequency deviation decreases, the proportional coefficient is controlled to change from the set maximum proportional coefficient to the optimal proportional coefficient.

[0022] This preferred solution adjusts the proportional coefficient to the optimal proportional coefficient when there is no frequency deviation in the power system, which can ensure that the wind turbines operate in the optimal state, thereby maximizing the use of wind energy. After the frequency deviation is reduced, the proportional coefficient is adjusted back to the optimal proportional coefficient in a timely manner, which helps the wind turbines to quickly restore a stable state and improve the overall stability of the system.

[0023] As a preferred solution, the frequency of the wind turbine generator set is adjusted once so that the working point of the wind turbine generator set is kept on the maximum power point tracking curve, specifically:

[0024] By adjusting the pitch angle of the wind turbine generator set, the size of the pitch static adjustment coefficient in the wind turbine generator set is adjusted and the change in the output power of the wind turbine generator set is controlled, so that the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

[0025] This preferred solution can effectively control the output power of the wind turbine by adjusting the pitch angle when the wind speed changes, so as to keep it near the rated power and avoid drastic fluctuations in the output power, thereby improving the stability of the power output.

[0026] As a preferred solution, the pitch static adjustment difference coefficient is specifically:

[0027] Based on the coefficient calculation formula, the pitch static adjustment error coefficient is calculated according to the pitch angle of the wind turbine when entering the constant power region and the pitch angle during load reduction operation;

[0028] The coefficient calculation formula is:

[0029]

[0030] Where Δf is the frequency deviation of the power system, σ β is the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the unit is operating at reduced load, β0 is the pitch angle of the wind turbine when it is operating at reduced load, and K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, and T1 is the time constant of the pitch angle regulator.

[0031] The present application also provides a virtual inertial control and primary frequency modulation stabilization device, including a deviation module, a coefficient module and a curve module;

[0032] The deviation module is used to reduce the frequency deviation by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit if the power system where the wind turbine generator set is located has a frequency deviation;

[0033] The coefficient module is used to transform the proportional coefficient for adjusting the wind turbine power output into an optimal proportional coefficient if the power system does not have a frequency deviation or after the frequency deviation is reduced; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine group;

[0034] The curve module is used to make the working point of the wind turbine set remain on the maximum power point tracking curve by performing a frequency adjustment on the wind turbine set.

[0035] As a preferred solution, the deviation module includes a linear unit and a deviation unit;

[0036] Wherein, the linear unit is used to set a dynamic proportional coefficient according to the deviation between the input frequency and the set frequency in the controller of the wind turbine set if the frequency deviation occurs in the power system where the wind turbine set is located, so that the output power of the wind turbine set changes linearly;

[0037] The deviation unit is used to reduce the frequency deviation by starting the wind turbine generator set when the frequency deviation is equal to the frequency lower limit.

[0038] As a preferred solution, the dynamic proportional coefficient is specifically:

[0039] Calculating the optimal proportional coefficient according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine generator set;

[0040] Calculating a maximum proportionality coefficient according to the wind speed and the rotor speed of the wind turbine generator set;

[0041] The weights of the optimal scale factor and the maximum scale factor are adjusted based on a dynamic factor to establish the dynamic scale factor.

[0042] As a preferred solution, the coefficient module includes a transform unit and a coefficient unit;

[0043] Wherein, the conversion unit is used to control the proportional coefficient to be converted into the optimal proportional coefficient if there is no frequency deviation in the power system; wherein the proportional coefficient is used to adjust the power output of the wind turbine;

[0044] The coefficient unit is used to control the proportional coefficient to change from the set maximum proportional coefficient to the optimal proportional coefficient after the frequency deviation is reduced.

[0045] As a preferred solution, the curve module is specifically:

[0046] By adjusting the pitch angle of the wind turbine generator set, the size of the pitch static adjustment coefficient in the wind turbine generator set is adjusted and the change in the output power of the wind turbine generator set is controlled, so that the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

[0047] As a preferred solution, the pitch static adjustment difference coefficient is specifically:

[0048] Based on the coefficient calculation formula, the pitch static adjustment error coefficient is calculated according to the pitch angle of the wind turbine when entering the constant power region and the pitch angle during load reduction operation;

[0049] The coefficient calculation formula is:

[0050]

[0051] Where Δf is the frequency deviation of the power system, σ β is the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the unit is operating at reduced load, β0 is the pitch angle of the wind turbine when it is operating at reduced load, and K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, and T1 is the time constant of the pitch angle regulator.

[0052] The present application also provides a storage medium, on which a computer program is stored. The computer program is called and executed by a computer to implement the above-mentioned virtual inertia control and primary frequency modulation stabilization method. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flow chart of a virtual inertial control and primary frequency modulation stabilization method provided in an embodiment of the present application;

[0054] Figure 2 is a dynamic factor characteristic diagram provided by an embodiment of the present application;

[0055] Figure 3 is a schematic diagram of a virtual inertia control strategy provided in an embodiment of the present application;

[0056] Figure 4 is a static frequency characteristic diagram of a wind turbine generator set provided in an embodiment of the present application;

[0057] Figure 5 This is a primary frequency modulation control structure diagram provided in an embodiment of the present application;

[0058] Figure 6 is a control flow chart provided in an embodiment of the present application;

[0059] Figure 7 is a structural diagram of a wind farm control system provided in an embodiment of the present application;

[0060] Figure 8 It is a structural diagram of the wind farm frequency regulation coordinated control strategy provided in the embodiment of the present application;

[0061] Fig. 9 It is a frequency change waveform diagram of the three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application;

[0062] Fig.10 It is a waveform diagram of system speed change of three control methods after a sudden load increase of 50MW provided in the embodiment of the present application;

[0063] Fig.11It is a waveform diagram of active output change of three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application;

[0064] Fig.12 is a random wind speed diagram provided in an embodiment of the present application;

[0065] Fig.13 is a frequency variation waveform diagram under continuous disturbance provided by an embodiment of the present application;

[0066] Fig.14 is a waveform diagram of speed change under continuous disturbance provided in an embodiment of the present application;

[0067] Fig.15 is a waveform diagram of active output variation under continuous disturbance provided by an embodiment of the present application;

[0068] Fig.16 It is a structural schematic diagram of a virtual inertial control and primary frequency modulation stabilization device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0070] In the description of this application, it should be understood that the term "first" is used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "several" means two or more.

[0071] A stabilization method of virtual inertia control and primary frequency modulation provided in an embodiment of the present application is mainly used in situations where a comprehensive control method based on the combination of primary frequency modulation and virtual inertia control is needed to avoid the impact of active power steps on the power system and effectively stabilize the power system.

[0072] Embodiment 1:

[0073] See also Figure 1 The embodiment of the present application provides a method for maintaining stability by virtual inertia control and primary frequency modulation, including S1 to S3, and the specific implementation steps are as follows:

[0074] S1. If a frequency deviation occurs in the power system where the wind turbine generator set is located, the frequency deviation can be reduced by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit.

[0075] Step S1 of the embodiment of the present application is specifically as follows:

[0076] Based on the power tracking curve of the wind turbine, the optimal proportional coefficient k is calculated according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine. opt ;

[0077] According to the wind speed and the rotor speed of the wind turbine, the maximum proportionality coefficient k is calculated. max ;

[0078] Adjusting the optimal proportional coefficient k based on the dynamic factor γ opt and the maximum proportionality factor k max weight, establish the dynamic proportional coefficient k v .

[0079] If the power system where the wind turbine is located has a frequency deviation, the wind turbine controller will use the set dynamic proportional coefficient k v , so that the output power of the wind turbine changes linearly; among them, "frequency deviation" refers to the deviation between the frequency of the power system and its working frequency;

[0080] By setting the frequency lower limit Δf l and upper frequency limit Δf h The controller is set to operate at a frequency deviation equal to the lower frequency limit Δf l The wind turbine is started at the right time to reduce the frequency deviation; the "controller" refers to the controller of the wind turbine, which is responsible for monitoring and controlling the operating status of the wind turbine, including parameters such as output power, speed and pitch angle.

[0081] Among them, the optimal proportional coefficient is:

[0082]

[0083] The maximum scale factor is:

[0084]

[0085] The dynamic scaling factor is:

[0086] k v =(1-γ)k opt +γk max

[0087] For the intermediate parameters λ' and γ:

[0088]

[0089] Where ρ is the air density, R is the length of the fan blade, C pmax is the maximum wind energy utilization coefficient, λ opt is the optimal tip speed ratio;

[0090] ω min is the minimum rotor speed; v' w To predict the rising wind speed, this embodiment is set to 12m / s;

[0091] γ is the dynamic factor, n is a positive integer, Δf l and Δf h are the set frequency deviation lower limit and frequency deviation upper limit respectively, Δf is the frequency deviation of the power system;

[0092] To apply the embodiments of this application, please refer to Figure 2 , Figure 2 It is a dynamic factor characteristic diagram provided in an embodiment of the present application, which shows the characteristics of the dynamic factor γ.

[0093] It should be noted that in this embodiment S1, the wind turbine generator system is set to operate when the system frequency deviation is close to Δf l When starting, the frequency drop is closer to Δf h , dynamic proportionality coefficient k v The closer it is to the maximum proportionality factor k max , the greater the active output of the fan is; therefore, it is equivalent to switching the proportional coefficient of the fan power output to the maximum proportional coefficient k when the frequency deviation occurs and the frequency deviation does not decrease. max ; Wherein, the proportionality coefficient refers to the proportionality coefficient used to dynamically adjust the power tracking curve to optimize the performance of the wind turbine;

[0094] When the frequency deviation decreases, the dynamic proportional coefficient k v Will gradually return to the optimal proportional coefficient k opt , so that the wind turbine can run on the MPPT curve (maximum power point tracking curve) again.

[0095] In this embodiment S1, the dynamic proportional coefficient is set according to the deviation between the input frequency and the set frequency, and the output power of the wind turbine can be adjusted in real time, so that it can quickly respond to the frequency deviation, thereby improving the response speed of the system; and the linear change of the output power helps to more accurately control the operating state of the wind turbine and reduce the system instability caused by the sudden change of the output power. When the frequency deviation is equal to the lower frequency limit, the wind turbine is started, and the frequency deviation is reduced by dynamically adjusting the output power, which helps to maintain the frequency stability of the power system;

[0096] For the dynamic proportional coefficient, by considering the maximum wind energy utilization coefficient and the optimal tip speed ratio, it is possible to ensure that the wind turbine operates in the optimal state, thereby maximizing the capture and utilization of wind energy. The calculation and application of the optimal proportional coefficient helps to reduce energy waste and improve the power generation efficiency of wind turbines. By adjusting the weights of the optimal proportional coefficient and the maximum proportional coefficient based on dynamic factors, the wind turbine can be adaptively adjusted according to the changes in real-time wind speed and rotor speed; this dynamic adjustment strategy helps wind turbines maintain efficient and stable operation in complex and changeable wind energy environments, and improves their adaptability and flexibility to the environment.

[0097] S2. If there is no frequency deviation in the power system or after the frequency deviation is reduced, the proportional coefficient for adjusting the wind turbine power output is transformed into an optimal proportional coefficient; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine.

[0098] Step S2 of the embodiment of the present application is specifically as follows:

[0099] If there is no frequency deviation in the power system, the control proportional coefficient is transformed into the optimal proportional coefficient k opt ;

[0100] After the frequency deviation decreases, the control proportional coefficient changes from the set maximum proportional coefficient k max Transformed into the optimal scale factor k opt .

[0101] To apply the embodiments of this application, please refer to Figure 3 , Figure 3 : is a schematic diagram of a virtual inertia control strategy provided by an embodiment of the present application, which shows the frequency modulation process of the virtual inertia control strategy; specifically, it includes:

[0102] ① When the wind speed is fixed at v1, the doubly fed wind turbine operates stably at point A under the MPPT working state;

[0103] ② If a large disturbance occurs in the power system, causing the frequency to drop rapidly, k opt will quickly increase to k max The electromagnetic power of the fan is changed from P A Surge to P B ;

[0104] ③ Since the electromagnetic power output by the fan is greater than the captured mechanical power, the rotor slows down and the fan operating point decreases along the BC curve until the fan runs stably at point C.

[0105] It should be noted that, combined with Figure 3 From the above-mentioned embodiment, at the end of steps S1 to S2, the fan is running at Figure 3Point C has not recovered to the MPPT curve of point A; therefore, it is necessary to subsequently change the operating point from point C to point A through a frequency modulation process in step S3 to restore to MPPT operation, that is, the pitch angle gradually decreases to move the wind turbine operating point upward, the operating point changes from C to A, the wind turbine speed increases, and the MPPT state is restored after inertial response.

[0106] In this embodiment S2, when there is no frequency deviation in the power system, the proportional coefficient is adjusted to the optimal proportional coefficient, which can ensure that the wind turbine operates in the optimal state, thereby maximizing the use of wind energy. After the frequency deviation is reduced, the proportional coefficient is adjusted back to the optimal proportional coefficient in a timely manner, which helps the wind turbine to quickly restore a stable state and improve the overall stability of the system.

[0107] S3. By adjusting the frequency of the wind turbine generator set once, the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

[0108] Step S3 of the embodiment of the present application is specifically as follows:

[0109] Integral link is introduced into the controller. Based on the coefficient calculation formula, according to the pitch angle of the wind turbine when entering the constant power area and the pitch angle during load reduction operation, the switch control signal S1 is used to select and configure the pitch static adjustment coefficient σ β ;

[0110] Based on the pitch static adjustment error coefficient σ β The static differential coefficient σ of the wind turbine is calculated by the first formula based on the actual operating conditions of the wind turbine and the reserved frequency regulation capacity. f ;

[0111] According to the first formula, the static adjustment coefficient σ of the wind turbine group f And the change of unit output power ΔP G The mutual influence relationship between them can be obtained to obtain the change of pitch angle and unit output power ΔP G The first change relationship between them.

[0112] Based on the first variation relationship, the pitch static adjustment error coefficient σ in the wind turbine is adjusted by reducing the pitch angle of the wind turbine (including the pitch angle β during normal operation and the pitch angle β0 during load reduction operation). β The size of the wind turbine output power and the change in the output power of the wind turbine generator set ΔP G , so that the fan operating point moves up, and the fan operating point rises smoothly along curve CA to point A, and the fan speed increases, so that the working point of the wind turbine set remains on the MPPT curve.

[0113] Among them, the first change relationship is specifically: pitch static adjustment difference coefficient σ βAs an intermediate parameter, since this coefficient satisfies the transformation formula and the frequency deviation Δf of the power system cannot be directly controlled, but the pitch angle can be directly adjusted, σ can be adjusted by adjusting the pitch angle. β The size of the static adjustment coefficient σ of the wind turbine can be determined according to the first formula f The size of the static adjustment coefficient σ of the wind turbine f The value of will affect the change in the unit output power ΔP G Therefore, mechanical power control can be achieved by adjusting the pitch angle to improve its power-frequency-static characteristics.

[0114] The coefficient calculation formula is:

[0115]

[0116] Furthermore, since in steady state, β, β ω and β0 remain unchanged, so the wind turbine pitch static adjustment coefficient can be expressed as a transformation formula, that is:

[0117]

[0118] The first formula is:

[0119]

[0120] Among them, for the parameter σ βn and σ βd have:

[0121]

[0122]

[0123] Where Δf is the frequency deviation of the power system, σ β is the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the wind turbine is operating at reduced load; β0 is the pitch angle of the wind turbine when it is operating at reduced load, and when S1=0, β0 is 0; K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, T1 is the time constant of the pitch angle regulator;

[0124] f1 and f0 are the frequency and power frequency of the power system, respectively; P1 and P0 are the output power and standard output power of the wind turbine at a certain time t, respectively; and f1, f0, P1 and P0 are related to the following Figure 4 The parameters in are corresponding;

[0125] σ βnis the static adjustment error coefficient of the variable speed wind turbine during normal operation, σ βd It is the static adjustment error coefficient of the pitch when the variable speed wind turbine is running at reduced load.

[0126] To apply the embodiments of this application, please refer to Figure 4 , Figure 4 is a static frequency characteristic diagram of a wind turbine generator set provided in an embodiment of the present application, which represents the static frequency characteristic of the wind turbine generator set;

[0127] The following combination Figure 4 To illustrate the static frequency characteristics of wind turbines:

[0128] ①When the system frequency is the industrial frequency f0, the output power is P0;

[0129] ② When the system load increases and the frequency drops to f1, the unit can increase the wind energy captured by reducing the pitch angle to β1, such as Figure 4 (b) and (c); the mechanical power is continuously increased to P1, and the frequency modulation is performed, such as Figure 4 (a) shown.

[0130] To apply the embodiments of this application, please refer to Figure 5 , Figure 5 is a primary frequency modulation control structure diagram provided in an embodiment of the present application, indicating that in this embodiment S3, in order to realize the setting of the static frequency characteristics of the wind turbine generator set, the controller introduces an integral link, and the corresponding pitch control structure;

[0131] exist Figure 5 In the figure, S1 is the switch control signal, which is used to control whether the unit is to operate with reduced load.

[0132] To apply the embodiments of this application, please refer to Figure 6-8 , Figure 6 is a control flow chart provided in an embodiment of the present application, which shows the general process of performing data control at different links in the first embodiment of the present invention to restore the wind turbine of the wind turbine set to the MPPT operation mode;

[0133] Figure 7 is a structural diagram of a wind farm control system provided in an embodiment of the present application, showing a control system where a wind turbine generator set in the first embodiment of the present application is located;

[0134] Figure 8 It is a structural diagram of the wind farm frequency coordination control strategy provided in the embodiment of the present application, which represents the strategy structure of data regulation in different links of the first embodiment of the present application.

[0135] The control scheme proposed in S3 of this embodiment complies with Figure 4The pitch angle-frequency response characteristics shown in the figure are shown, and the power is adjusted according to the first change relationship, so that the wind turbine can effectively cope with the drop or rise of the system frequency, thereby showing a power-frequency static characteristic similar to that of a conventional power generation unit, and performing a frequency adjustment. In addition, when the wind speed changes, by adjusting the pitch angle, the output power of the wind turbine can be effectively controlled to keep it near the rated power, avoiding drastic fluctuations in the output power, thereby improving the stability of the power output;

[0136] In addition, the primary frequency regulation control strategy can adjust the static power frequency characteristics of the wind turbine by setting the pitch static adjustment coefficient, which can meet the requirements of the wind turbine to participate in the primary frequency regulation of the system, thereby reducing the steady-state frequency deviation of the system. The comprehensive control strategy combining virtual inertia and primary frequency regulation enables the wind turbine to not only have a controllable inertial response, but also perform primary frequency regulation according to the static frequency characteristics of the unit, improving the wind farm's ability to support the system frequency, giving full play to the frequency regulation capability of the wind farm and effectively supporting the grid frequency.

[0137] In order to verify the feasibility of the frequency support control method proposed in this application, the wind turbine does not participate in frequency regulation (method 1), virtual inertia control (method 2), and the control strategy proposed in this application (method 3) are compared under the condition of sudden load increase, as follows:

[0138] To apply the embodiments of this application, please refer to Figure 9-11 , Fig. 9 This is a frequency change waveform diagram of the three control methods after a sudden load increase of 50MW provided in the embodiment of the present application. Fig.10 The system speed change waveform diagram of the three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application is shown in FIG. Fig.11 It is a waveform diagram of active output change of three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application;

[0139] At 15 seconds, the system load increases by 50MW and the wind speed is fixed at 11m / s. Fig. 9 , Fig.10 and Fig.11 As shown in the figure, when method 1 is used, there is almost no response to the change of system frequency; when method 2 is used, the rate of change of system frequency is reduced, but the change is not obvious enough; when method 3 is used, power can be quickly increased for frequency support, with a high response speed, the minimum frequency value is increased from 49.44Hz to 49.85Hz, and the drop amplitude is reduced by 73.2%. In addition, the speed of the wind turbine is reduced during the frequency dynamic process, which releases kinetic energy and plays a certain inertial support role for the system. The effect is significantly better than virtual inertial control.

[0140] To apply the embodiments of this application, please refer to Figure 12-15 , Fig.12is a random wind speed diagram provided in the embodiment of the present application, Fig.13 is a frequency change waveform diagram under continuous disturbance provided in an embodiment of the present application, Fig.14 is a waveform diagram of speed change under continuous disturbance provided in an embodiment of the present application, Fig.15 is a waveform diagram of active output variation under continuous disturbance provided by an embodiment of the present application;

[0141] In order to further verify the effectiveness of the strategy proposed in this application in actual operation, a white noise sequence is used to simulate random wind speed, such as Fig.12 As shown;

[0142] The system load is set to increase by 50MW at 15s and 25MW at 25s to verify the effect of the comprehensive control strategy proposed in this invention under continuous disturbance. The simulation results are shown in Fig.13 , Fig.14 and Fig.15 ;Depend on Fig.13 It can be seen that after the first load disturbance, the comprehensive control has the best effect on improving the lowest point of the system frequency; after the second load disturbance, the virtual inertia control has the most obvious effect on improving the lowest point of the system frequency, but an obvious second drop occurs at 32.46s. Fig.14 and Fig.15 It can be seen that the comprehensive control releases the most rotor kinetic energy and increases the active power to the maximum. In general, the comprehensive control strategy proposed in this application can quickly respond to frequency changes under continuous disturbances. The frequency drop after two disturbances has been significantly weakened, avoiding the second drop in frequency, and the speed also shows a downward trend in the frequency dynamic process, releasing the rotor kinetic energy and rapidly increasing the active power, playing a good inertial support role.

[0143] Overall, this embodiment has the following beneficial effects:

[0144] In the present application, the starting process of the wind turbine itself is a smooth power output process, rather than a sudden, step-like power change. Therefore, starting the wind turbine when the frequency deviation reaches the lower limit can gradually and smoothly increase the active power output of the power system, thereby avoiding the impact of the step change in active power on the power system. In the case where there is no frequency deviation in the wind turbine or the frequency deviation has been reduced, by adjusting the proportional coefficient to the optimal value, the output power of the wind turbine can be optimized so that it can be connected to the power system more smoothly and the step change in active power can be reduced. This smooth power output helps to reduce the impact on the power system and improve the stability of the power system. A single frequency adjustment can quickly respond to the frequency change of the power system. Therefore, finally stabilizing the frequency of the power system by adjusting the output power of the wind turbine not only helps to maintain the stability of the power system, but also improves the anti-interference ability of the power system.

[0145] In addition, the virtual inertia control based on the dynamic power tracking proportional coefficient in the scheme can avoid the impact caused by active power steps, and can quickly increase the electromagnetic power for frequency support when the frequency drops deeply, which can effectively improve the degree of frequency drop and ensure the operating stability of the power system.

[0146] Embodiment 2:

[0147] See also Fig.16 , the embodiment of the present application provides a virtual inertial control and primary frequency modulation stabilization device, including a deviation module 10, a coefficient module 20 and a curve module 30;

[0148] The deviation module 10 is used to reduce the frequency deviation by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit if the power system where the wind turbine generator set is located has a frequency deviation;

[0149] The coefficient module 20 is used to convert the proportional coefficient for adjusting the wind turbine power output into an optimal proportional coefficient if there is no frequency deviation in the power system or after the frequency deviation is reduced; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine;

[0150] The curve module 30 is used to make the working point of the wind turbine generator set remain on the maximum power point tracking curve by performing a frequency adjustment on the wind turbine generator set.

[0151] In one embodiment, the deviation module 10 includes a linear unit and a deviation unit;

[0152] Among them, the linear unit is used to calculate the optimal proportional coefficient k based on the power tracking curve of the wind turbine, according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine. opt ;

[0153] The linear unit is also used to calculate the maximum proportionality coefficient k according to the wind speed and the rotor speed of the wind turbine. max ;

[0154] Linear unit, also used to adjust the optimal scaling factor k based on the dynamic factor γ opt and the maximum proportionality factor k max weight, establish the dynamic proportional coefficient k v .

[0155] Linear unit, used in the wind turbine controller, if the power system where the wind turbine is located has frequency deviation, according to the set dynamic proportional coefficient k v , so that the output power of the wind turbine changes linearly; among them, "frequency deviation" refers to the deviation between the frequency of the power system and its working frequency;

[0156] Deviation unit, used to set the lower frequency limit Δf l and upper frequency limit Δf h The controller is set to operate at a frequency deviation equal to the lower frequency limit Δf l The wind turbine is started at the right time to reduce the frequency deviation; the "controller" refers to the controller of the wind turbine, which is responsible for monitoring and controlling the operating status of the wind turbine, including parameters such as output power, speed and pitch angle.

[0157] Among them, the optimal proportional coefficient is:

[0158]

[0159] The maximum scale factor is:

[0160]

[0161] The dynamic scaling factor is:

[0162] k v =(1-γ)k opt +γk max

[0163] For the intermediate parameters λ' and γ:

[0164]

[0165] Where ρ is the air density, R is the length of the fan blade, C pmax is the maximum wind energy utilization coefficient, λ opt is the optimal tip speed ratio;

[0166] ω min is the minimum rotor speed; v' w To predict the rising wind speed, this embodiment is set to 12m / s;

[0167] γ is the dynamic factor, n is a positive integer, Δf l and Δf h are the set frequency deviation lower limit and frequency deviation upper limit respectively, Δf is the frequency deviation of the power system;

[0168] To apply the embodiments of this application, please refer to Figure 2 , Figure 2 It is a dynamic factor characteristic diagram provided in an embodiment of the present application, which shows the characteristics of the dynamic factor γ.

[0169] It should be noted that the deviation module 10 of this embodiment enables the wind turbine to generate a frequency deviation close to Δf l When starting, the frequency drop is closer to Δf h , dynamic proportionality coefficient k vThe closer it is to the maximum proportionality factor k max , the greater the active output of the fan is; therefore, it is equivalent to switching the proportional coefficient of the fan power output to the maximum proportional coefficient k when the frequency deviation occurs and the frequency deviation does not decrease. max ; Wherein, the proportionality coefficient refers to the proportionality coefficient used to dynamically adjust the power tracking curve to optimize the performance of the wind turbine;

[0170] When the frequency deviation decreases, the dynamic proportional coefficient k v Will gradually return to the optimal proportional coefficient k opt , so that the wind turbine can run on the MPPT curve (maximum power point tracking curve) again.

[0171] The deviation module 10 of this embodiment sets a dynamic proportional coefficient according to the deviation between the input frequency and the set frequency, and can adjust the output power of the wind turbine in real time, so that it can quickly respond to the frequency deviation, thereby improving the response speed of the system; and the linear change of the output power helps to more accurately control the operating state of the wind turbine and reduce the system instability caused by the sudden change of the output power. When the frequency deviation is equal to the lower frequency limit, the wind turbine is started, and the frequency deviation is reduced by dynamically adjusting the output power, which helps to maintain the frequency stability of the power system;

[0172] For the dynamic proportional coefficient, by considering the maximum wind energy utilization coefficient and the optimal tip speed ratio, it is possible to ensure that the wind turbine operates in the optimal state, thereby maximizing the capture and utilization of wind energy. The calculation and application of the optimal proportional coefficient helps to reduce energy waste and improve the power generation efficiency of wind turbines. By adjusting the weights of the optimal proportional coefficient and the maximum proportional coefficient based on dynamic factors, the wind turbine can be adaptively adjusted according to the changes in real-time wind speed and rotor speed; this dynamic adjustment strategy helps wind turbines maintain efficient and stable operation in complex and changeable wind energy environments, and improves their adaptability and flexibility to the environment.

[0173] In one embodiment, the coefficient module 20 includes a transform unit and a coefficient unit;

[0174] The conversion unit is used to control the proportional coefficient to be converted to the optimal proportional coefficient k if there is no frequency deviation in the power system. opt ;

[0175] The coefficient unit is used to control the proportional coefficient from the set maximum proportional coefficient k after the frequency deviation decreases. max Transformed into the optimal scale factor k opt .

[0176] To apply the embodiments of this application, please refer to Figure 3 , Figure 3: is a schematic diagram of a virtual inertia control strategy provided by an embodiment of the present application, which shows the frequency modulation process of the virtual inertia control strategy; specifically, it includes:

[0177] ① When the wind speed is fixed at v1, the doubly fed wind turbine operates stably at point A under the MPPT working state;

[0178] ② If a large disturbance occurs in the power system, causing the frequency to drop rapidly, k opt will quickly increase to k max The electromagnetic power of the fan is changed from P A Surge to P B ;

[0179] ③ Since the electromagnetic power output by the fan is greater than the captured mechanical power, the rotor slows down and the fan operating point decreases along the BC curve until the fan runs stably at point C.

[0180] It should be noted that, combined with Figure 3 From the above-mentioned embodiment, when the deviation module 10 and the coefficient module 20 are finished, the fan is running at Figure 3 Point C has not recovered to the MPPT curve of point A; therefore, it is necessary to subsequently change the operating point from point C to point A through a frequency modulation process of the curve module 30 to restore to MPPT operation, that is, the pitch angle gradually decreases to move the wind turbine operating point upward, the operating point changes from C to A, the wind turbine speed increases, and the MPPT state is restored after inertial response.

[0181] In this embodiment, the coefficient module 20 adjusts the proportional coefficient to the optimal proportional coefficient when there is no frequency deviation in the power system, which can ensure that the wind turbine generator set operates in the optimal state, thereby maximizing the use of wind energy. After the frequency deviation is reduced, the proportional coefficient is adjusted back to the optimal proportional coefficient in a timely manner, which helps the wind turbine generator set to quickly restore a stable state and improve the overall stability of the system.

[0182] In one embodiment, the curve module 30 is specifically:

[0183] Integral link is introduced into the controller. Based on the coefficient calculation formula, according to the pitch angle of the wind turbine when entering the constant power area and the pitch angle during load reduction operation, the switch control signal S1 is used to select and configure the pitch static adjustment coefficient σ β ;

[0184] Based on the pitch static adjustment error coefficient σ β The static differential coefficient σ of the wind turbine is calculated by the first formula based on the actual operating conditions of the wind turbine and the reserved frequency regulation capacity. f ;

[0185] According to the first formula, the static adjustment coefficient σ of the wind turbine group f And the change of unit output power ΔPG The mutual influence relationship between them can be obtained to obtain the change of pitch angle and unit output power ΔP G The first change relationship between them.

[0186] Based on the first variation relationship, the pitch static adjustment error coefficient σ in the wind turbine is adjusted by reducing the pitch angle of the wind turbine (including the pitch angle β during normal operation and the pitch angle β0 during load reduction operation). β The size of the wind turbine output power and the change in the output power of the wind turbine generator set ΔP G , so that the fan operating point moves up, and the fan operating point rises smoothly along curve CA to point A, and the fan speed increases, so that the working point of the wind turbine set remains on the MPPT curve.

[0187] Among them, the first change relationship is specifically: pitch static adjustment difference coefficient σ β As an intermediate parameter, since this coefficient satisfies the transformation formula and the frequency deviation Δf of the power system cannot be directly controlled, but the pitch angle can be directly adjusted, σ can be adjusted by adjusting the pitch angle. β The size of the static adjustment coefficient σ of the wind turbine can be determined according to the first formula f The size of the static adjustment coefficient σ of the wind turbine f The value of will affect the change in the unit output power ΔP G Therefore, mechanical power control can be achieved by adjusting the pitch angle to improve its power-frequency-static characteristics.

[0188] The coefficient calculation formula is:

[0189]

[0190] Furthermore, since in steady state, β, β ω and β0 remain unchanged, so the wind turbine pitch static adjustment coefficient can be expressed as a transformation formula, that is:

[0191]

[0192] The first formula is:

[0193]

[0194] Among them, for the parameter σ βn and σ βd have:

[0195]

[0196] Where Δf is the frequency deviation of the power system, σ βis the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the wind turbine is operating at reduced load; β0 is the pitch angle of the wind turbine when it is operating at reduced load, and when S1=0, β0 is 0; K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, T1 is the time constant of the pitch angle regulator;

[0197] f1 and f0 are the frequency and power frequency of the power system, respectively; P1 and P0 are the output power and standard output power of the wind turbine at a certain time t, respectively; and f1, f0, P1 and P0 are related to the following Figure 4 The parameters in are corresponding;

[0198] σ βn is the static adjustment error coefficient of the variable speed wind turbine during normal operation, σ βd It is the static adjustment error coefficient of the pitch when the variable speed wind turbine is running at reduced load.

[0199] To apply the embodiments of this application, please refer to Figure 4 , Figure 4 is a static frequency characteristic diagram of a wind turbine generator set provided in an embodiment of the present application, which represents the static frequency characteristic of the wind turbine generator set;

[0200] The following combination Figure 4 To illustrate the static frequency characteristics of wind turbines:

[0201] ①When the system frequency is the industrial frequency f0, the output power is P0;

[0202] ② When the system load increases and the frequency drops to f1, the unit can increase the wind energy captured by reducing the pitch angle to β1, such as Figure 4 (b) and (c); the mechanical power is continuously increased to P1, and the frequency modulation is performed, such as Figure 4 (a) shown.

[0203] To apply the embodiments of this application, please refer to Figure 5 , Figure 5 It is a primary frequency modulation control structure diagram provided in an embodiment of the present application, which shows that the curve module 30 of the present embodiment introduces an integral link in the controller to achieve the setting of the static frequency characteristics of the wind turbine, and the corresponding pitch control structure;

[0204] exist Figure 5 In the figure, S1 is the switch control signal, which is used to control whether the unit is to operate with reduced load.

[0205] To apply the embodiments of this application, please refer to Figure 6-8 , Figure 6is a control flow chart provided in an embodiment of the present application, which shows the general process of performing data control in different links in the second embodiment to restore the wind turbine to the MPPT operation mode;

[0206] Figure 7 is a structural diagram of a wind farm control system provided in an embodiment of the present application, showing a control system where a wind turbine generator set in the second embodiment of the present application is located;

[0207] Figure 8 It is a structural diagram of the wind farm frequency coordination control strategy provided in the embodiment of the present application, which represents the strategy structure of data regulation in different links of the second embodiment of the present application.

[0208] The control scheme proposed in S3 of this embodiment complies with Figure 4 The pitch angle-frequency response characteristics shown in the figure are shown, and the power is adjusted according to the first change relationship, so that the wind turbine can effectively cope with the drop or rise of the system frequency, thereby showing a power-frequency static characteristic similar to that of a conventional power generation unit, and performing a frequency adjustment. In addition, when the wind speed changes, by adjusting the pitch angle, the output power of the wind turbine can be effectively controlled to keep it near the rated power, avoiding drastic fluctuations in the output power, thereby improving the stability of the power output;

[0209] In addition, the primary frequency regulation control strategy can adjust the static power frequency characteristics of the wind turbine by setting the pitch static adjustment coefficient, which can meet the requirements of the wind turbine to participate in the primary frequency regulation of the system, thereby reducing the steady-state frequency deviation of the system. The comprehensive control strategy combining virtual inertia and primary frequency regulation enables the wind turbine to not only have a controllable inertial response, but also perform primary frequency regulation according to the static frequency characteristics of the unit, improving the wind farm's ability to support the system frequency, giving full play to the frequency regulation capability of the wind farm and effectively supporting the grid frequency.

[0210] In order to verify the feasibility of the frequency support control method proposed in this application, the wind turbine does not participate in frequency regulation (method 1), virtual inertia control (method 2), and the control strategy proposed in this application (method 3) are compared under the condition of sudden load increase, as follows:

[0211] To apply the embodiments of this application, please refer to Figure 9-11 , Fig. 9 This is a frequency change waveform diagram of the three control methods after a sudden load increase of 50MW provided in the embodiment of the present application. Fig.10 The system speed change waveform diagram of the three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application is shown in FIG. Fig.11 It is a waveform diagram of active output change of three control methods after the load suddenly increases by 50MW provided in the embodiment of the present application;

[0212] At 15 seconds, the system load increases by 50MW and the wind speed is fixed at 11m / s. Fig. 9 , Fig.10 and Fig.11 As shown in the figure, when method 1 is used, there is almost no response to the change of system frequency; when method 2 is used, the rate of change of system frequency is reduced, but the change is not obvious enough; when method 3 is used, power can be quickly increased for frequency support, with a high response speed, the minimum frequency value is increased from 49.44Hz to 49.85Hz, and the drop amplitude is reduced by 73.2%. In addition, the speed of the wind turbine is reduced during the frequency dynamic process, which releases kinetic energy and plays a certain inertial support role for the system. The effect is significantly better than virtual inertial control.

[0213] To apply the embodiments of this application, please refer to Figure 12-15 , Fig.12 is a random wind speed diagram provided in the embodiment of the present application, Fig.13 is a frequency change waveform diagram under continuous disturbance provided in an embodiment of the present application, Fig.14 is a waveform diagram of speed change under continuous disturbance provided in an embodiment of the present application, Fig.15 is a waveform diagram of active output variation under continuous disturbance provided by an embodiment of the present application;

[0214] In order to further verify the effectiveness of the strategy proposed in this application in actual operation, a white noise sequence is used to simulate random wind speed, such as Fig.12 As shown;

[0215] The system load is set to increase by 50MW at 15s and 25MW at 25s to verify the effect of the comprehensive control strategy proposed in this invention under continuous disturbance. The simulation results are shown in Fig.13 , Fig.14 and Fig.15 ;Depend on Fig.13 It can be seen that after the first load disturbance, the comprehensive control has the best effect on improving the lowest point of the system frequency; after the second load disturbance, the virtual inertia control has the most obvious effect on improving the lowest point of the system frequency, but an obvious second drop occurs at 32.46s. Fig.14 and Fig.15 It can be seen that the comprehensive control releases the most rotor kinetic energy and increases the active power to the maximum. In general, the comprehensive control strategy proposed in this application can quickly respond to frequency changes under continuous disturbances. The frequency drop after two disturbances has been significantly weakened, avoiding the second drop in frequency, and the speed also shows a downward trend in the frequency dynamic process, releasing the rotor kinetic energy and rapidly increasing the active power, playing a good inertial support role.

[0216] Overall, this embodiment has the following beneficial effects:

[0217] In the present application, the starting process of the wind turbine itself is a smooth power output process, rather than a sudden, step-like power change. Therefore, starting the wind turbine when the frequency deviation reaches the lower limit can gradually and smoothly increase the active power output of the power system, thereby avoiding the impact of the step change in active power on the power system. In the case where there is no frequency deviation in the wind turbine or the frequency deviation has been reduced, by adjusting the proportional coefficient to the optimal value, the output power of the wind turbine can be optimized so that it can be connected to the power system more smoothly and the step change in active power can be reduced. This smooth power output helps to reduce the impact on the power system and improve the stability of the power system. A single frequency adjustment can quickly respond to the frequency change of the power system. Therefore, finally stabilizing the frequency of the power system by adjusting the output power of the wind turbine not only helps to maintain the stability of the power system, but also improves the anti-interference ability of the power system.

[0218] In addition, the virtual inertia control based on the dynamic power tracking proportional coefficient in the scheme can avoid the impact caused by active power steps, and can quickly increase the electromagnetic power for frequency support when the frequency drops deeply, which can effectively improve the degree of frequency drop and ensure the operating stability of the power system.

[0219] Embodiment three:

[0220] An embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the virtual inertia control and primary frequency modulation stabilization method;

[0221] Wherein, the virtual inertial control and primary frequency modulation stabilization method, if implemented in the form of a software functional unit and used as an independent product, can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0222] The above are preferred embodiments of the present invention. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A virtual inertial control and primary frequency modulation stabilization method, characterized in that: include: If a frequency deviation occurs in the power system where the wind turbine generator set is located, the frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit; If the power system does not have a frequency deviation or after the frequency deviation is reduced, the proportional coefficient for adjusting the wind turbine power output is transformed into an optimal proportional coefficient; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine; By performing a frequency adjustment on the wind turbine generator set, the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

2. A method for maintaining stability by virtual inertia control and primary frequency modulation as claimed in claim 1, characterized in that: If a frequency deviation occurs in the power system where the wind turbine generator set is located, the frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit, specifically: If the frequency deviation occurs in the power system where the wind turbine generator set is located, a dynamic proportional coefficient is set in the controller of the wind turbine generator set according to the deviation between the input frequency and the set frequency, so that the output power of the wind turbine generator set changes linearly; The frequency deviation is reduced by starting the wind turbine generator set when the frequency deviation is equal to the frequency lower limit.

3. A method for maintaining stability by virtual inertia control and primary frequency modulation as claimed in claim 2, characterized in that: The dynamic proportional coefficient is specifically: Calculating the optimal proportional coefficient according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine generator set; Calculating a maximum proportionality coefficient according to the wind speed and the rotor speed of the wind turbine generator set; The weights of the optimal scale factor and the maximum scale factor are adjusted based on a dynamic factor to establish the dynamic scale factor.

4. A method for maintaining stability by virtual inertia control and primary frequency modulation as claimed in claim 1, characterized in that: If the power system does not have a frequency deviation or after the frequency deviation is reduced, the proportional coefficient for adjusting the wind turbine power output is transformed to an optimal proportional coefficient, specifically: If the power system has no frequency deviation, the control proportional coefficient is transformed into the optimal proportional coefficient; wherein the proportional coefficient is used to adjust the wind turbine power output; After the frequency deviation decreases, the proportional coefficient is controlled to change from the set maximum proportional coefficient to the optimal proportional coefficient.

5. A virtual inertia control and primary frequency modulation stabilization method as claimed in claim 1, characterized in that: By performing a frequency adjustment on the wind turbine generator set, the working point of the wind turbine generator set is kept on the maximum power point tracking curve, specifically: By adjusting the pitch angle of the wind turbine generator set, the size of the pitch static adjustment coefficient in the wind turbine generator set is adjusted and the change in the output power of the wind turbine generator set is controlled, so that the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

6. A method for maintaining stability by virtual inertia control and primary frequency modulation as claimed in claim 5, characterized in that: The pitch static adjustment difference coefficient is specifically: Based on the coefficient calculation formula, the pitch static adjustment error coefficient is calculated according to the pitch angle of the wind turbine when entering the constant power region and the pitch angle during load reduction operation; The coefficient calculation formula is: Where Δf is the frequency deviation of the power system, σ β is the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the unit is operating at reduced load, β0 is the pitch angle of the wind turbine when it is operating at reduced load, and K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, and T1 is the time constant of the pitch angle regulator.

7. A virtual inertial control and primary frequency modulation stabilization device, characterized in that: Includes deviation module, coefficient module and curve module; The deviation module is used to reduce the frequency deviation by starting the wind turbine generator set when the frequency deviation is equal to the lower frequency limit if the power system where the wind turbine generator set is located has a frequency deviation; The coefficient module is used to transform the proportional coefficient for adjusting the wind turbine power output into an optimal proportional coefficient if the power system does not have a frequency deviation or after the frequency deviation is reduced; wherein the optimal proportional coefficient is calculated based on the power tracking curve of the wind turbine group; The curve module is used to make the working point of the wind turbine set remain on the maximum power point tracking curve by performing a frequency adjustment on the wind turbine set.

8. A virtual inertia control and primary frequency modulation stabilization device as claimed in claim 7, characterized in that: The deviation module includes a linear unit and a deviation unit; Wherein, the linear unit is used to set a dynamic proportional coefficient according to the deviation between the input frequency and the set frequency in the controller of the wind turbine set if the frequency deviation occurs in the power system where the wind turbine set is located, so that the output power of the wind turbine set changes linearly; The deviation unit is used to reduce the frequency deviation by starting the wind turbine generator set when the frequency deviation is equal to the frequency lower limit.

9. A virtual inertia control and primary frequency modulation stabilization device as claimed in claim 8, characterized in that: The dynamic proportional coefficient is specifically: Calculating the optimal proportional coefficient according to the maximum wind energy utilization coefficient and the optimal blade tip speed ratio of the wind turbine generator set; Calculating a maximum proportionality coefficient according to the wind speed and the rotor speed of the wind turbine generator set; The weights of the optimal scale factor and the maximum scale factor are adjusted based on a dynamic factor to establish the dynamic scale factor.

10. A virtual inertia control and primary frequency modulation stabilization device as claimed in claim 7, characterized in that: The coefficient module includes a transform unit and a coefficient unit; Wherein, the conversion unit is used to control the proportional coefficient to be converted into the optimal proportional coefficient if there is no frequency deviation in the power system; wherein the proportional coefficient is used to adjust the power output of the wind turbine; The coefficient unit is used to control the proportional coefficient to change from the set maximum proportional coefficient to the optimal proportional coefficient after the frequency deviation is reduced.

11. A virtual inertia control and primary frequency modulation stabilization device as claimed in claim 7, characterized in that: The curve module is specifically: By adjusting the pitch angle of the wind turbine generator set, the size of the pitch static adjustment coefficient in the wind turbine generator set is adjusted and the change in the output power of the wind turbine generator set is controlled, so that the working point of the wind turbine generator set is kept on the maximum power point tracking curve.

12. A virtual inertia control and primary frequency modulation stabilization device as claimed in claim 11, characterized in that: The pitch static adjustment difference coefficient is specifically: Based on the coefficient calculation formula, the pitch static adjustment error coefficient is calculated according to the pitch angle of the wind turbine when entering the constant power region and the pitch angle during load reduction operation; The coefficient calculation formula is: Where Δf is the frequency deviation of the power system, σ β is the pitch static adjustment error coefficient to be solved, β is the pitch angle of the wind turbine when it is operating normally, S1 is the switch control signal that controls whether the unit is operating at reduced load, β0 is the pitch angle of the wind turbine when it is operating at reduced load, and K δ is the frequency magnification, s is the complex number in Laplace transform, β ω is the pitch angle of the wind turbine when it enters the constant power region, and T1 is the time constant of the pitch angle regulator.

13. A storage medium, characterized in that: The storage medium stores a computer program, which is called and executed by a computer to implement a virtual inertia control and primary frequency modulation stabilization method as described in any one of claims 1 to 6 above.

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