Adaptive control method and device for parameters of frequency modulation participated by network construction type wind power plant

Abstract

The invention discloses a parameter adaptive control method and device for frequency modulation participation of a network construction type wind power plant. The method comprises the following steps: respectively establishing an inertia adaptive curve model and a droop adaptive curve model of each wind turbine generator set; distributing a corresponding cooperative control coefficient for each droop adaptive curve model to obtain a droop adaptive curve cooperative control model of each wind turbine generator set; in the frequency modulation process from power disturbance to maximum frequency deviation of the system, the inertia coefficient and the droop coefficient of each wind turbine generator set are respectively changed according to the corresponding inertia adaptive curve model and the corresponding droop adaptive curve cooperative control model; in the frequency modulation recovery process after the system has the maximum frequency deviation, the inertia coefficient of each wind turbine generator set is maintained at the set minimum inertia coefficient, and the droop coefficient of each wind turbine generator set continues to change according to the corresponding droop adaptive curve cooperative control model; therefore, cooperative control of each wind power set in the wind power plant participating in system frequency modulation is completed.

Description

Technical Field

[0001] The present invention relates to the field of wind power technology, and in particular to a parameter adaptive control method and device for a grid-type wind farm participating in frequency modulation. Background Art

[0002] With the rapid development of new energy and the gradual expansion of installed capacity, the strength of the power grid has gradually decreased. Grid-following wind farms based on phase-locked loop operation are difficult to adapt to the weak power grid structure dominated by new energy. For this reason, relevant researchers have proposed grid-type control of wind turbines. Grid-type wind turbines can actively participate in the construction of grid frequency and voltage, and then actively respond to system frequency changes. However, in the common fixed parameter frequency regulation method, the frequency regulation capability of a single unit in a grid-type wind farm is relatively weak and cannot achieve coordinated control between wind turbines. At present, a variety of solutions have been proposed for the research on improving the frequency regulation capability of grid-type wind farms, such as:

[0003] 1. Related research disclosed "Virtual synchronous generator control strategy based on adaptive inertia damping integrated control algorithm". This method designed an adaptive inertia damping integrated control (SA-RIDC) algorithm, which optimized the frequency regulation capability of wind turbines through the staggered control of virtual rotational inertia and virtual damping. However, this method can only improve the frequency regulation capability of a single unit, and cannot achieve coordinated control between units in the station, making it impossible for units with different frequency regulation capabilities to fully exert their frequency regulation capabilities. The overall frequency regulation capability of the wind farm needs to be improved.

[0004] 2. Related research also disclosed "Cooperative frequency support control of wind farms taking into account differences in wind turbine operating status". This method uses a leaderless consistency algorithm in the frequency support stage to enable wind turbines to exchange status information with adjacent wind turbines in real time, realize power distribution, and improve the frequency regulation capability of wind farms; however, the consistency algorithm used in this method is relatively difficult and difficult to apply to actual projects.

[0005] 3. Related research also disclosed a "virtual inertia multi-machine collaborative control strategy for wind farms considering frequency regulation capability". This method introduces a collaborative control coefficient to achieve coordinated allocation of frequency regulation auxiliary power between low wind speed wind farms; however, this method does not consider the impact of communication delay between wind farms and wind turbines on power allocation, resulting in low accuracy of collaborative regulation allocation.

[0006] In summary, most of the existing parameter adaptive control strategies for grid-type wind farms participating in frequency regulation only adopt station-level control or unit-level control, and lack consideration of the droop coefficient in frequency regulation control; when it comes to station-level control, although the leaderless consistency algorithm can realize the distribution of frequency regulation power within the station, this strategy does not consider the impact of station delay on power distribution and lacks practical engineering considerations; therefore, the current ability of grid-type wind farms to participate in frequency regulation needs to be further optimized. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the present invention provides a parameter adaptive control method and device for a grid-type wind farm participating in frequency regulation. By combining station-level control with unit-level control, the frequency regulation effect of inertia control and droop control of the wind farm is improved, the frequency support capability of the grid-type wind farm is enhanced, and the frequency safety of the power grid operation is ensured.

[0008] The present invention adopts the following technical solution.

[0009] In a first aspect, the present invention provides a parameter adaptive control method for a grid-type wind farm participating in frequency modulation, the method comprising the following steps:

[0010] S1. Establishing the inertia adaptive curve model and droop adaptive curve model of each wind turbine in the wind farm respectively;

[0011] S2. Determine the frequency regulation potential of each wind turbine generator set according to the operating status of each wind turbine generator set when a power disturbance occurs in the system, so as to assign a corresponding coordinated control coefficient to each of the droop adaptive curve models, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine generator set;

[0012] S3. During the frequency modulation process from the occurrence of power disturbance in the system to the occurrence of the maximum frequency deviation, the inertia coefficient and droop coefficient of each wind turbine unit are changed according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model;

[0013] S4. During the frequency recovery process after the system has the maximum frequency deviation, the inertia coefficient of each wind turbine is maintained at the set minimum inertia coefficient, and the droop coefficient of each wind turbine continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine in the wind farm participating in the system frequency regulation.

[0014] Optionally, in step S1, the expression of the inertia adaptive curve model of each wind turbine generator set established is as follows:

[0015]

[0016] In the formula, is the inertia coefficient of the i-th wind turbine in the wind farm; is the current speed of the i-th wind turbine; is the inertia coefficient protection increment of the i-th wind turbine; is the inertia adaptive curve of the i-th wind turbine; ω N is the rated speed of the wind turbine.

[0017] Optionally, the expression of the inertia adaptive curve of the i-th wind turbine set is as follows:

[0018]

[0019] In the formula, is the inertia coefficient corresponding to the i-th wind turbine unit during steady-state operation, is the absolute value of the system frequency change rate, J max is the maximum value of the inertia coefficient of the wind turbine, is the dead zone of the inertia adaptive curve of the i-th wind turbine.

[0020] Optionally, the inertia coefficient protection increment of the i-th wind turbine group The calculation formula is as follows:

[0021]

[0022] In the formula, Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding inertia coefficient, J min is the minimum inertia coefficient of the wind turbine.

[0023] Optionally, in step S1, the expression of the droop adaptive curve model of each wind turbine generator set established is as follows:

[0024]

[0025] In the formula, is the droop coefficient of the i-th wind turbine unit, is the current speed of the i-th wind turbine, is the droop coefficient protection increment of the i-th wind turbine unit, is the droop adaptive curve of the i-th wind turbine, ω N is the rated speed of the wind turbine.

[0026] Optionally, the expression of the droop adaptive curve of the i-th wind turbine generator set is as follows:

[0027]

[0028] In the formula, is the droop coefficient corresponding to the i-th wind turbine unit in steady-state operation, Δf is the absolute value of the system frequency deviation, D max is the maximum droop coefficient of the wind turbine, is the dead zone of the droop adaptive curve of the i-th wind turbine.

[0029] Optionally, the droop coefficient protection increment of the i-th wind turbine generator set is The calculation formula is as follows:

[0030]

[0031] In the formula, Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding droop coefficient, D min is the minimum droop coefficient of the wind turbine.

[0032] Optionally, in step S2, the step of allocating a corresponding collaborative control coefficient to each of the droop adaptive curve models includes:

[0033] S2.1. For wind turbines that use overspeed load shedding control, the maximum rotor kinetic energy that can be used by the wind turbine under the current disturbance is calculated to characterize its frequency regulation potential, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use overspeed load shedding control is used as the coordinated control coefficient of its droop adaptive curve model;

[0034] S2.2. For wind turbines that use pitch angle load reduction control, their frequency regulation potential is characterized by calculating the maximum output power that the wind turbine can call under the current disturbance, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use pitch angle load reduction control is used as the collaborative control coefficient of its droop adaptive curve model.

[0035] Optionally, in step S2, for a wind turbine generator system adopting overspeed load reduction control, the expression of the droop adaptive curve collaborative control model is as follows:

[0036]

[0037] In the formula, is the droop adaptive curve collaborative control model of the vth wind turbine using overspeed load reduction control; k v_down k represents the coordinated control coefficient of the droop coefficient distribution for the vth wind turbine using overspeed load reduction when a sudden load disturbance occurs, v_up represents the coordinated control coefficient of the droop coefficient allocation for the vth wind turbine using overspeed load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the vth wind turbine generator set.

[0038] Optionally, in step S2, for a wind turbine generator system using pitch angle load reduction control, the expression of the droop adaptive curve collaborative control model is as follows:

[0039]

[0040] In the formula, is the droop adaptive curve collaborative control model of the u-th wind turbine using pitch angle load reduction control; h u_down It represents the coordinated control coefficient of the droop coefficient distribution of the u-th propeller using pitch angle load reduction control when a sudden load disturbance occurs, h u_up represents the coordinated control coefficient of the droop coefficient allocation for the u-th wind turbine using pitch angle load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the u-th wind turbine.

[0041] In a second aspect, the present invention provides a parameter adaptive control device for a grid-type wind farm participating in frequency modulation, which runs the steps of any method described in the first aspect of the present invention, and the device comprises:

[0042] Establishing a module for respectively establishing an inertia adaptive curve model and a droop adaptive curve model for each wind turbine in the wind farm;

[0043] An allocation module is used to determine the frequency regulation potential of each wind turbine group according to the operating state of each wind turbine group when a power disturbance occurs in the system, so as to allocate a corresponding coordinated control coefficient to each droop adaptive curve model, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine group;

[0044] The first frequency modulation module is used to change the inertia coefficient and droop coefficient of each wind turbine unit according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model during the frequency modulation process from power disturbance to maximum frequency deviation;

[0045] The second frequency regulation module is used to maintain the inertia coefficient of each wind turbine set at the set minimum inertia coefficient during the frequency recovery process after the system has the maximum frequency deviation, and the droop coefficient of each wind turbine set continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine set in the wind farm participating in the system frequency regulation.

[0046] In a third aspect, the present invention provides a terminal, including a processor and a storage medium;

[0047] The storage medium is used to store instructions;

[0048] The processor is used to operate according to the instructions to execute the steps of any one of the methods described in the first aspect of the present invention.

[0049] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods described in the first aspect of the present invention.

[0050] The beneficial effects of the present invention are as follows:

[0051] 1. In view of the defect that the existing research on the control strategy for improving the frequency regulation capability of wind farms only adopts station-level control or unit-level control alone, and lacks the coordinated optimization and regulation of station-level control and unit-level control; the present invention proposes a wind farm frequency regulation parameter adaptive control strategy combining station-level control and unit-level control; in station-level control, the present invention calculates the maximum frequency regulation potential of wind turbines of different load reduction types, and gives the wind turbine droop parameter coordination coefficient to adapt to the operating conditions of wind turbines under different wind speeds, so as to achieve that the wind turbines with stronger frequency regulation capability in the wind farm can better exert their own frequency regulation performance, so that each unit with different frequency regulation capability can give full play to its frequency regulation capability, and improve the overall frequency regulation capability of the wind farm; in unit-level control, the present invention sets an inertia / droop adaptive curve model to control the adaptive change of frequency regulation parameters, and further improves the frequency regulation capability of a single unit.

[0052] 2. Considering that the main purpose of the system inertia response is to reduce the maximum rate of change of the system frequency, and there is a communication delay between the station controller and the unit controller, the time when the maximum rate of change of the system frequency occurs is faster than the time when the station sends the coordination signal to the unit; and the main purpose of the droop response of the grid-type wind turbine unit is to reduce the maximum deviation of the system frequency and the transient frequency deviation of the system, both of which appear slower than the time when the station sends the coordination signal to the unit; therefore, in order to save the communication cost of the station, the present invention does not send the coordination coefficient for the inertia at the station level control, but only sends the droop coordination coefficient to each unit in the wind farm, so as to improve the accuracy of the coordinated regulation allocation.

[0053] 3. The inertia adaptive curve model and droop adaptive curve model established in the present invention can achieve the control target that the larger the system frequency change rate is, the larger the inertia coefficient and the droop coefficient are, thereby improving the frequency regulation efficiency of the inertia response and the droop response; in addition, the present invention also designs a droop / inertia coefficient protection increment to reduce the frequency regulation power increase of the wind turbine when it is running at a low speed, and effectively avoid the wind turbine running at a low speed from stalling and disconnecting from the grid due to excessive output of the increased frequency regulation power.

[0054] 4. Experimental results show that the present invention improves the frequency regulation effect of inertia control and droop control of the wind farm by combining station-level control with unit-level control, enhances the frequency support capability of the grid-type wind farm, and improves the frequency stability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a flow chart of the parameter adaptive control method of the grid-type wind farm participating in frequency modulation in the present invention;

[0056] Figure 2 It is a schematic diagram of the structure of a wind power grid-connected simulation model in an embodiment of the present invention;

[0057] Figure 3 The wind speed distribution diagram of the wind farm in the simulation system according to the embodiment of the present invention is shown in FIG.

[0058] Figure 4 This is a simulation result diagram of a grid-type wind turbine generator system in a low wind speed scenario when a sudden load increase disturbance occurs in an embodiment of the present invention;

[0059] Figure 5 The simulation result diagram of the grid-type wind turbine in the embodiment of the present invention when a sudden load increase disturbance occurs in a high wind speed scenario

[0060] Figure 6 It is a structural principle block diagram of a parameter adaptive control device for a grid-type wind farm participating in frequency modulation in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in the present invention are only part of the embodiments of the present invention, not all of the embodiments. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0062] Embodiment 1:

[0063] Reference Figure 1 The embodiment of the present invention provides a parameter adaptive control method for a grid-type wind farm participating in frequency modulation, which specifically includes the following steps:

[0064] S1. Establishing the inertia adaptive curve model and droop adaptive curve model of each wind turbine in the wind farm respectively;

[0065] S2. Determine the frequency regulation potential of each wind turbine generator set according to the operating status of each wind turbine generator set when a power disturbance occurs in the system, so as to assign a corresponding coordinated control coefficient to each of the droop adaptive curve models, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine generator set;

[0066] S3. During the frequency modulation process from the occurrence of power disturbance in the system to the occurrence of the maximum frequency deviation, the inertia coefficient and droop coefficient of each wind turbine unit are changed according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model;

[0067] S4. During the frequency recovery process after the system has the maximum frequency deviation, the inertia coefficient of each wind turbine is maintained at the set minimum inertia coefficient, and the droop coefficient of each wind turbine continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine in the wind farm participating in the system frequency regulation.

[0068] Specifically, when power disturbance occurs in the power system, the inertia coefficient and droop coefficient of each wind turbine in the wind farm are changed according to the set adaptive curve; while the parameters of the wind turbine using overspeed load reduction control are adaptively changed, the wind farm terminal controller analyzes the frequency regulation potential of different wind turbines using overspeed load reduction control in the station, and allocates a coordinated control coefficient to the droop coefficient of each wind turbine using overspeed load reduction control; while the parameters of the wind turbine using pitch angle control are adaptively changed, the wind farm terminal controller analyzes the frequency regulation potential of different wind turbines using pitch angle control in the station, and allocates a coordinated control coefficient to the droop coefficient of each wind turbine using pitch angle control; when the system frequency is in the recovery process, in order to improve the frequency recovery speed, the inertia J of each wind turbine is reduced to J min , the droop coefficient D continues to change according to the specified adaptive curve.

[0069] Furthermore, the specific contents of step S1 include:

[0070] S1.1. The expression for setting the inertia adaptive curve of each wind turbine unit is as follows:

[0071]

[0072] In the formula, is the inertia coefficient corresponding to the i-th wind turbine unit during steady-state operation, is the absolute value of the system frequency change rate, J max is the maximum value of the inertia coefficient of the wind turbine, J max The value of is determined according to the onshore wind turbine grid connection standard (GB / T19963.1-2021). In this embodiment, J max =12. is the dead zone of the inertia adaptive curve of the i-th wind turbine. Value less than or equal to The inertia of the wind turbine remains unchanged. Value greater than The inertia coefficient of the wind turbine increases with gradually increases with the increase of According to (GB / T 19963.1-2021), in this embodiment It is 0.03Hz.

[0073] It is further explained that the inertia adaptive curve designed in this embodiment is different from the traditional linear curve in which the inertia coefficient J can only change linearly with the change of df / dt. The present invention introduces the use of an exponential function expression to achieve the control goal that the larger the df / dt is, the greater the rate of change of the inertia coefficient J is, thereby improving the efficiency of inertia response frequency modulation.

[0074] S1.2, considering that the wind turbine speed is less than 0.7ω N When the wind turbine generator set has a low speed, it will stall and disconnect from the grid. Therefore, in this embodiment, when the wind turbine generator set speed is less than 0.75ω N The inertia coefficient is reduced to ensure the stability of the wind turbine speed, so the expression of the inertia adaptive curve model in the speed protection process is as follows:

[0075]

[0076] In the formula, is the inertia coefficient of the i-th wind turbine in the wind farm; is the current speed of the i-th wind turbine; is the inertia coefficient protection increment of the i-th wind turbine; is the inertia adaptive curve of the i-th wind turbine, ω N is the rated speed of the wind turbine.

[0077] As a preferred but non-limiting embodiment of the present invention, the calculation formula for the inertia coefficient protection increment of the wind turbine set provided by the present invention is as follows:

[0078]

[0079] In the formula, Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding inertia coefficient, J min is the minimum inertia coefficient of the wind turbine, where J min The value of is determined according to the onshore wind turbine grid connection standard (GB / T 19963.1-2021). min =8.

[0080] It is further explained that when the speed of the wind turbine is less than 0.75ω NWhen the inertia coefficient protection increment designed by the embodiment of the present invention gradually reduces the inertia coefficient, so as to reduce the frequency regulation power increase of the wind turbine set and thus avoid the wind turbine set stalling and disconnecting from the grid due to excessive output of increased frequency regulation power.

[0081] S1.3. Set the droop adaptive curve expression of each wind turbine as follows:

[0082]

[0083] In the formula, is the droop coefficient corresponding to the i-th wind turbine unit in steady-state operation, Δf is the absolute value of the system frequency deviation, D max is the maximum droop coefficient of the wind turbine, D max The value of is determined according to the onshore wind turbine grid connection standard (GB / T19963.1-2021). In this embodiment, D max =50, is the dead zone of the droop adaptive curve of the i-th wind turbine. When the Δf value is less than or equal to When the wind turbine droop coefficient remains unchanged, the Δf value is greater than When Δf increases, the droop coefficient of the wind turbine increases gradually. According to (GB / T 19963.1-2021), It is 0.03Hz.

[0084] It is further explained that the droop adaptive curve designed in this embodiment is different from the traditional linear curve in which the droop coefficient D can only change linearly with the change of Δf. The present invention introduces the use of an exponential function expression to achieve the control goal that the larger the Δf, the greater the rate of change of the droop coefficient D, thereby improving the efficiency of the droop response frequency modulation.

[0085] S1.4, when the wind turbine speed is less than 0.75ω N At the same time, a rotor protection link is introduced into the droop coefficient adaptive control to ensure the stability of the wind turbine speed, so that the expression of the droop adaptive curve model in the speed protection process is as follows:

[0086]

[0087] In the formula, is the droop coefficient of the i-th wind turbine unit, is the current speed of the i-th wind turbine, is the droop coefficient protection increment of the i-th wind turbine unit, is the droop adaptive curve of the i-th wind turbine.

[0088] As a preferred but non-limiting embodiment of the present invention, the calculation formula for the droop coefficient protection increment of the wind turbine set provided by the present invention is as follows:

[0089]

[0090] In the formula, Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding droop coefficient, D min is the minimum droop coefficient of the wind turbine, D min The value of is determined according to the onshore wind turbine grid connection standard (GB / T19963.1-2021). In this embodiment, D min =10.

[0091] It is further explained that when the speed of the wind turbine is less than 0.75ω N The droop coefficient protection increment designed by the embodiment of the present invention gradually reduces the droop coefficient to reduce the wind turbine frequency modulation power increase and thus prevent the wind turbine from stalling and disconnecting from the grid due to excessive output of increased frequency modulation power.

[0092] As an embodiment of the present invention, the content of step S2 includes:

[0093] S2.1. For wind turbines that use overspeed load shedding control, the maximum rotor kinetic energy that can be used by the wind turbine under the current disturbance is calculated to characterize its frequency regulation potential, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use overspeed load shedding control is used as the coordinated control coefficient of its droop adaptive curve model; specifically:

[0094] (1) When a sudden power surge occurs, the maximum rotor kinetic energy that can be used by a wind turbine using overspeed load reduction control is expressed as:

[0095]

[0096] In the formula, is the maximum rotor kinetic energy that can be used by the vth wind turbine in the wind farm using overspeed load reduction control, is the rotor inertia of the vth wind turbine, ω0 is the stable operating speed of the wind turbine, ω min It is the lower speed limit for stable operation of wind turbine.

[0097] Furthermore, when a sudden load disturbance occurs, the expression of the coordinated control coefficient of the droop coefficient distribution of the wind turbine using overspeed load reduction control is:

[0098]

[0099] In the formula, k v_downis the coordinated control coefficient for the droop coefficient of the wind turbine set that uses overspeed load reduction when a sudden load increase disturbance occurs at the vth station, n low_wind is the total number of wind turbines that adopt overspeed load reduction control strategy.

[0100] (2) When a sudden power reduction disturbance occurs, the maximum rotor kinetic energy that can be used by a wind turbine using overspeed load reduction control is expressed as:

[0101]

[0102] In the formula, It is the maximum rotor kinetic energy that can be called upon by the vth wind turbine in the wind farm that adopts overspeed load reduction control.

[0103] Furthermore, when a sudden load reduction disturbance occurs, the expression of the coordinated control coefficient of the droop coefficient distribution of the wind turbine using overspeed load reduction control is:

[0104]

[0105] In the formula, k v_up is the coordinated control coefficient for the droop coefficient of the wind turbine set that uses overspeed load reduction when a sudden load reduction disturbance occurs at the vth unit, n low_wind is the total number of wind turbines that adopt overspeed load reduction control strategy.

[0106] As an embodiment of the present invention, for a wind turbine generator set adopting overspeed load reduction control, the expression of the droop adaptive curve coordinated control model is as follows:

[0107]

[0108] In the formula, is the droop adaptive curve collaborative control model of the vth wind turbine using overspeed load reduction control; k v_down k represents the coordinated control coefficient of the droop coefficient distribution for the vth wind turbine using overspeed load reduction when a sudden load disturbance occurs, v_up represents the coordinated control coefficient of the droop coefficient allocation for the vth wind turbine using overspeed load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the vth wind turbine generator set.

[0109] S2.2. For wind turbines that use pitch angle load reduction control, their frequency regulation potential is characterized by calculating the maximum output power that the wind turbine can call under the current disturbance, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use pitch angle load reduction control is used as the collaborative control coefficient of its droop adaptive curve model.

[0110] (1) When a sudden power disturbance occurs, the maximum output power that can be used by a wind turbine using pitch angle load reduction control is expressed as:

[0111]

[0112] Where ρ is the air density, R is the blade radius of the wind turbine, v is the wind speed of the wind turbine, and C p is the wind energy utilization coefficient of the wind turbine, λ is the tip blade speed ratio of the wind turbine, β0 is the pitch angle corresponding to the steady-state operation of the wind turbine, P max is the maximum output power of the wind turbine, and P0 is the output power of the wind turbine during steady-state operation.

[0113] Furthermore, when a sudden load disturbance occurs, the expression of the coordinated control coefficient of the droop coefficient distribution of the wind turbine using pitch angle load reduction control is:

[0114]

[0115] In the formula, h u_down is the coordinated control coefficient of the droop coefficient of the wind turbine using pitch angle load reduction when a sudden load increase disturbance occurs at the uth wind turbine, n high_wind is the total number of wind turbines using the pitch angle load reduction control strategy, is the maximum power that the u-th wind turbine can output.

[0116] (2) When a sudden power reduction disturbance occurs, the total frequency modulation power that can be used by the wind turbine using pitch angle load reduction control is expressed as:

[0117]

[0118] In the formula, β max It is the rated maximum variation of the wind turbine pitch angle.

[0119] Furthermore, when a sudden load reduction disturbance occurs, the expression of the coordinated control coefficient of the droop coefficient distribution of the wind turbine using pitch angle load reduction control is:

[0120]

[0121] In the formula, h u_up is the coordinated control coefficient of the droop coefficient of the wind turbine using pitch angle load reduction when a sudden load reduction disturbance occurs at the uth wind turbine, n high_wind is the total number of wind turbines using the pitch angle load reduction control strategy, is the maximum power that the u-th wind turbine can output.

[0122] As an embodiment of the present invention, for a wind turbine generator set adopting overspeed load reduction control, the expression of the droop adaptive curve coordinated control model is as follows:

[0123]

[0124] In the formula, is the droop adaptive curve collaborative control model of the vth wind turbine using overspeed load reduction control; k v_down k represents the coordinated control coefficient of the droop coefficient distribution for the vth wind turbine using overspeed load reduction when a sudden load disturbance occurs, v_up represents the coordinated control coefficient of the droop coefficient allocation for the vth wind turbine using overspeed load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the vth wind turbine generator set.

[0125] It is particularly noted that the parameter adaptive control method for grid-type wind farms participating in frequency modulation provided by the embodiment of the present invention has strong versatility and is not limited by wind turbine types such as double-fed and direct-drive.

[0126] In order to verify the effectiveness and practicality of the parameter adaptive control method for the grid-type wind farm participating in frequency modulation proposed in the present invention, the present invention has established the following based on Matlab / Simulink: Figure 2 The wind power grid-connected simulation model shown in the figure is Figure 2 Where T1 is the transformer on the synchronous machine side, T2 is the transformer on the wind farm side, Z1 is the transmission line impedance on the synchronous machine side, Z2 is the transmission line impedance on the wind farm side, L1 is the total system load, and L2 is the system variable load. The system parameters are shown in Table 1:

[0127] Table 1 Simulation system parameters

[0128]

[0129] In the design of the simulation environment, two simulation scenarios, low wind speed and high wind speed, are used to verify the effectiveness of the method proposed in the present invention. It should be noted that the operation state of the wind turbine corresponding to the low wind speed is to operate in an overspeed load reduction control mode; the operation state of the wind turbine corresponding to the high wind speed is to operate in a pitch angle load reduction control mode. Figure 3 The wind speed distribution diagram in the station is shown below. Figure 3 (a) is the wind speed distribution diagram in the low wind speed scenario, where there are 10 wind turbines with wind speeds of 6m / s-6.5m / s, 20 wind turbines with wind speeds of 6.5m / s-7m / s, 19 wind turbines with wind speeds of 7m / s-7.5m / s, and 11 wind turbines with wind speeds of 7.5m / s-8m / s. Figure 3(b) is the wind speed distribution diagram under the high wind speed scenario, where there are 10 wind turbines with wind speeds of 9m / s-9.5m / s, 20 wind turbines with wind speeds of 9.5m / s-10m / s, 17 wind turbines with wind speeds of 10m / s-10.5m / s, and 13 wind turbines with wind speeds of 0.5m / s-11m / s.

[0130] like Figure 4 As shown in the figure, it is the simulation result diagram of the grid-type wind turbine when a sudden load disturbance occurs in the low wind speed scenario; Figure 4 (a)(b) It can be seen that when power disturbance occurs, the output power of the wind turbine using the method proposed in the present invention is improved. Compared with the traditional adaptive control strategy, the maximum rate of change of system frequency of the method proposed in the present invention is reduced by 0.0014Hz / s, and the maximum deviation of system frequency is reduced by 0.001Hz. Figure 4 (c)(d) It can be seen that the method proposed in the present invention increases the output power of wind turbines with stronger frequency regulation capabilities, and correspondingly reduces the output power of wind turbines with weaker frequency regulation capabilities, thereby avoiding the risk of wind turbines stalling and disconnecting from the grid.

[0131] like Figure 5 As shown in the figure, it is the simulation result diagram of the grid-type wind turbine when a sudden load disturbance occurs in the high wind speed scenario; Figure 5 (a)(b) It can be seen that when power disturbance occurs, the output power of the wind turbine using the method proposed in the present invention is improved. Compared with the traditional adaptive control strategy, the maximum rate of change of system frequency of the method proposed in the present invention is reduced by 0.005Hz / s, and the maximum deviation of system frequency is reduced by 0.031Hz. Figure 5 (c)(d) It can be seen that the control strategy proposed in the present invention increases the output power of wind turbines with stronger frequency regulation capabilities, and correspondingly reduces the output power of wind turbines with weaker frequency regulation capabilities, thus avoiding the risk of wind turbines stalling and disconnecting from the grid.

[0132] The beneficial effects of the present invention are as follows:

[0133] 1. In view of the defect that the existing research on the control strategy for improving the frequency regulation capability of wind farms only adopts station-level control or unit-level control alone, and lacks the coordinated optimization and regulation of station-level control and unit-level control; the present invention proposes a wind farm frequency regulation parameter adaptive control strategy combining station-level control and unit-level control; in station-level control, the present invention calculates the maximum frequency regulation potential of wind turbines of different load reduction types, and gives the wind turbine droop parameter coordination coefficient to adapt to the operating conditions of wind turbines under different wind speeds, so as to achieve that the wind turbines with stronger frequency regulation capability in the wind farm can better exert their own frequency regulation performance, so that each unit with different frequency regulation capability can give full play to its frequency regulation capability, and improve the overall frequency regulation capability of the wind farm; in unit-level control, the present invention sets an inertia / droop adaptive curve model to control the adaptive change of frequency regulation parameters, and further improves the frequency regulation capability of a single unit.

[0134] 2. Considering that the main purpose of the system inertia response is to reduce the maximum rate of change of the system frequency, and there is a communication delay between the station controller and the unit controller, the time when the maximum rate of change of the system frequency occurs is faster than the time when the station sends the coordination signal to the unit; and the main purpose of the droop response of the grid-type wind turbine unit is to reduce the maximum deviation of the system frequency and the transient frequency deviation of the system, both of which appear slower than the time when the station sends the coordination signal to the unit; therefore, in order to save the communication cost of the station, the present invention does not send the coordination coefficient for the inertia at the station level control, but only sends the droop coordination coefficient to each unit in the wind farm, so as to improve the accuracy of the coordinated regulation allocation.

[0135] 3. The inertia adaptive curve model and droop adaptive curve model established in the present invention can achieve the control target that the larger the system frequency change rate is, the larger the inertia coefficient and the droop coefficient are, thereby improving the frequency regulation efficiency of the inertia response and the droop response; in addition, the present invention also designs a droop / inertia coefficient protection increment to reduce the frequency regulation power increase of the wind turbine when it is running at a low speed, and effectively avoid the wind turbine running at a low speed from stalling and disconnecting from the grid due to excessive output of the increased frequency regulation power.

[0136] 4. Experimental results show that the present invention improves the frequency regulation effect of inertia control and droop control of the wind farm by combining station-level control with unit-level control, enhances the frequency support capability of the grid-type wind farm, and improves the frequency stability of the power system.

[0137] Embodiment 2:

[0138] Reference Figure 6 The present invention provides a parameter adaptive control device for a grid-type wind farm participating in frequency modulation, the device is used to implement the steps of the method in the above embodiment 1, and the device specifically includes:

[0139] Establishing a module for respectively establishing an inertia adaptive curve model and a droop adaptive curve model for each wind turbine in the wind farm;

[0140] An allocation module is used to determine the frequency regulation potential of each wind turbine group according to the operating state of each wind turbine group when a power disturbance occurs in the system, so as to allocate a corresponding coordinated control coefficient to each droop adaptive curve model, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine group;

[0141] The first frequency modulation module is used to change the inertia coefficient and droop coefficient of each wind turbine unit according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model during the frequency modulation process from power disturbance to maximum frequency deviation;

[0142] The second frequency regulation module is used to maintain the inertia coefficient of each wind turbine set at the set minimum inertia coefficient during the frequency recovery process after the system has the maximum frequency deviation, and the droop coefficient of each wind turbine set continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine set in the wind farm participating in the system frequency regulation.

[0143] The parameter adaptive control device for the grid-type wind farm participating in frequency regulation provided in the embodiment of the present invention and the parameter adaptive control method for the grid-type wind farm participating in frequency regulation provided in Example 1 are based on the same technical concept, and can produce the beneficial effects as described in Example 1. For the contents not described in detail in this embodiment, please refer to Example 1.

[0144] Embodiment three:

[0145] A terminal provided by an embodiment of the present invention includes a processor and a storage medium;

[0146] The storage medium is used to store instructions;

[0147] The processor is used to operate according to the instruction to execute the steps of the method according to any one of the first embodiments.

[0148] Embodiment 4:

[0149] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of any method described in Embodiment 1 are implemented.

[0150] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0151] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0152] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0153] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A parameter adaptive control method for grid-type wind farms participating in frequency modulation, characterized in that: The method comprises the following steps: S1. Establishing the inertia adaptive curve model and droop adaptive curve model of each wind turbine in the wind farm respectively; S2. Determine the frequency regulation potential of each wind turbine generator set according to the operating status of each wind turbine generator set when a power disturbance occurs in the system, so as to assign a corresponding coordinated control coefficient to each of the droop adaptive curve models, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine generator set; S3. During the frequency modulation process from the occurrence of power disturbance in the system to the occurrence of the maximum frequency deviation, the inertia coefficient and droop coefficient of each wind turbine unit are changed according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model; S4. During the frequency recovery process after the system has the maximum frequency deviation, the inertia coefficient of each wind turbine is maintained at the set minimum inertia coefficient, and the droop coefficient of each wind turbine continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine in the wind farm participating in the system frequency regulation.

2. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 1 is characterized in that: In step S1, the expression of the inertia adaptive curve model of each wind turbine generator set is as follows: In the formula, is the inertia coefficient of the i-th wind turbine in the wind farm; ω i r is the current speed of the i-th wind turbine; J i ω is the inertia coefficient protection increment of the i-th wind turbine; J i proposed is the inertia adaptive curve of the i-th wind turbine; ω N is the rated speed of the wind turbine.

3. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 2 is characterized in that: The expression of the inertia adaptive curve of the i-th wind turbine set is as follows: In the formula, J i 0 is the inertia coefficient corresponding to the i-th wind turbine unit during steady-state operation, is the absolute value of the system frequency change rate, J max is the maximum value of the inertia coefficient of the wind turbine, λ i J is the dead zone of the inertia adaptive curve of the i-th wind turbine.

4. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 2 is characterized in that: The inertia coefficient protection increment J of the i-th wind turbine group i ω The calculation formula is as follows: In the formula, J i r Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding inertia coefficient, J min is the minimum inertia coefficient of the wind turbine.

5. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 1 is characterized in that: In step S1, the expression of the droop adaptive curve model of each wind turbine generator set is as follows: In the formula, is the droop coefficient of the i-th wind turbine, ω i r is the current speed of the i-th wind turbine, D i ω is the droop coefficient protection increment of the i-th wind turbine unit, D i proposed is the droop adaptive curve of the i-th wind turbine, ω N is the rated speed of the wind turbine.

6. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 5 is characterized in that: The expression of the droop adaptive curve of the i-th wind turbine generator set is as follows: Where D i 0 is the droop coefficient corresponding to the i-th wind turbine in steady-state operation, |Δf| is the absolute value of the system frequency deviation, D max is the maximum droop coefficient of the wind turbine, λ i D is the dead zone of the droop adaptive curve of the i-th wind turbine.

7. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 5 is characterized in that: The droop coefficient protection increment D of the i-th wind turbine generator set i ω The calculation formula is as follows: Where D i r Indicates that the speed of the i-th wind turbine unit drops to 0.75ω N The corresponding droop coefficient, D min is the minimum droop coefficient of the wind turbine.

8. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 5 is characterized in that: In step S2, the step of assigning a corresponding collaborative control coefficient to each of the droop adaptive curve models includes: S2.

1. For wind turbines that use overspeed load shedding control, the maximum rotor kinetic energy that can be used by the wind turbine under the current disturbance is calculated to characterize its frequency regulation potential, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use overspeed load shedding control is used as the coordinated control coefficient of its droop adaptive curve model; S2.

2. For wind turbines that use pitch angle load reduction control, their frequency regulation potential is characterized by calculating the maximum output power that the wind turbine can call under the current disturbance, and the ratio of the frequency regulation potential of the wind turbine to the average frequency regulation potential of all wind turbines that currently use pitch angle load reduction control is used as the collaborative control coefficient of its droop adaptive curve model.

9. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 8 is characterized in that: In step S2, for the wind turbine generator set adopting overspeed load reduction control, the expression of the droop adaptive curve collaborative control model is as follows: In the formula, is the droop adaptive curve collaborative control model of the vth wind turbine using overspeed load reduction control; k v_down represents the coordinated control coefficient of the droop coefficient distribution for the vth wind turbine using overspeed load reduction when a sudden load increase disturbance occurs, k v_up represents the coordinated control coefficient of the droop coefficient allocation for the vth wind turbine using overspeed load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the vth wind turbine generator set.

10. The parameter adaptive control method for grid-type wind farm participating in frequency modulation according to claim 8, characterized in that: In step S2, for a wind turbine using pitch angle load reduction control, the expression of the droop adaptive curve collaborative control model is as follows: In the formula, is the droop adaptive curve collaborative control model of the u-th wind turbine using pitch angle load reduction control; h u_down It represents the coordinated control coefficient of the droop coefficient distribution of the u-th propeller using pitch angle load reduction control when a sudden load disturbance occurs, h u_up represents the coordinated control coefficient of the droop coefficient allocation for the u-th wind turbine using pitch angle load reduction control when a sudden load reduction disturbance occurs; is the droop coefficient of the u-th wind turbine.

11. A parameter adaptive control device for a grid-type wind farm participating in frequency modulation, running the parameter adaptive control method for a grid-type wind farm participating in frequency modulation as claimed in any one of claims 1 to 10, characterized in that: The device includes: Establishing a module for respectively establishing an inertia adaptive curve model and a droop adaptive curve model for each wind turbine in the wind farm; An allocation module is used to determine the frequency regulation potential of each wind turbine group according to the operating state of each wind turbine group when a power disturbance occurs in the system, so as to allocate a corresponding coordinated control coefficient to each droop adaptive curve model, thereby obtaining a droop adaptive curve coordinated control model of each wind turbine group; The first frequency modulation module is used to change the inertia coefficient and droop coefficient of each wind turbine unit according to the corresponding inertia adaptive curve model and droop adaptive curve collaborative control model during the frequency modulation process from power disturbance to maximum frequency deviation; The second frequency regulation module is used to maintain the inertia coefficient of each wind turbine set at the set minimum inertia coefficient during the frequency recovery process after the system has the maximum frequency deviation, and the droop coefficient of each wind turbine set continues to change according to its corresponding droop adaptive curve collaborative control model to complete the collaborative control of each wind turbine set in the wind farm participating in the system frequency regulation.

12. A terminal comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1-10.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

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