Adaptive coordinated frequency support control method considering disturbance event severity

Abstract

The application discloses an adaptive cooperative frequency support control method considering disturbance event severity, and belongs to the field of power safe operation, and comprises the following steps: S1, determining an initial cooperative coefficient based on capacity proportion and a comprehensive frequency modulation margin factor; S2, judging an operation scene based on a comparison result of allocated frequency modulation power of each wind farm and a sum of maximum allowed output power of all wind turbines in the wind farm; S3, modifying the cooperative coefficient of the wind turbine group in a conventional scene; S4, secondary modification of the cooperative coefficient of part of the wind farms in an extreme operation scene; and S5, the modified cooperative coefficient of all the wind farms. The adaptive cooperative frequency support control method considering disturbance event severity is used to quantitatively evaluate the severity of the disturbance event and the difference in frequency modulation capacity, realize adaptive dynamic adjustment of the cooperative coefficient in the conventional to extreme scenes, and improve the frequency stability and anti-disturbance capacity of the high-proportion wind power system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power safe operation, and particularly relates to an adaptive cooperative frequency support control method considering the severity of disturbance events. BACKGROUND

[0002] In a power system with high proportion of wind power, the scale of wind farm group is large and the operating states of internal units are significantly different. The traditional frequency modulation control mode is insufficient to deal with extreme disturbance. When a large power shortage (such as 540 MW load surge) occurs in the system, the traditional strategy lacks a secondary adjustment mechanism, which easily leads to simultaneous over-limit of multiple wind farms and aggravates the risk of frequency collapse. At the same time, there is a lack of quantitative evaluation of the boundary of wind turbine frequency modulation capacity, which cannot define the applicable range of the cooperative coefficient, resulting in reduced reliability of the control strategy under large disturbance. SUMMARY

[0003] The purpose of the present application is to provide an adaptive cooperative frequency support control method considering the severity of disturbance events, which solves the above technical problems.

[0004] To achieve the above purpose, the present application provides an adaptive cooperative frequency support control method considering the severity of disturbance events, comprising the following steps:

[0005] S1, obtaining the comprehensive frequency modulation margin factor proportion, capacity information, disturbance power and critical disturbance power of each wind farm, and determining the initial cooperative coefficient based on the capacity proportion and the comprehensive frequency modulation margin factor;

[0006] S2, judging the operating scenario based on the comparison result of the frequency modulation power allocated to each wind farm and the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints;

[0007] When the frequency modulation power allocated to each wind farm is less than or equal to the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined as a normal scenario, and step S3 is executed;

[0008] When the frequency modulation power allocated to part of the wind farms is greater than the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined as an extreme operating scenario, and step S4 is executed;

[0009] When the frequency modulation power allocated to all wind farms is greater than the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined as a full extreme scenario, and step S5 is executed;

[0010] S3, correction of the cooperative coefficient of the wind turbine group in the normal scenario;

[0011] S31, calculate the safe operation margin factor of each wind turbine group in the wind farm, and determine whether each wind turbine group has the ability to perform frequency modulation task according to the comparison result of the safe operation margin factor and the initial coordination coefficient, if yes, determine that the current wind turbine group is an un-limited wind turbine group, and control according to the initial coordination coefficient, otherwise, determine that the current wind turbine group is a limited wind turbine group, and execute step S32;

[0012] S32, set the output power of one of the limited wind turbine groups as the maximum allowed output power, output the maximum allowed coordination coefficient, and update the remaining frequency modulation power;

[0013] S33, the remaining limited wind turbine group re-distributes the remaining frequency modulation power according to the capacity proportion, and corrects the initial coordination coefficient;

[0014] S34, determine the rationality of the corrected initial coordination coefficient, if yes, output the corrected initial coordination coefficient, otherwise, return to step S32, and set the output power of another limited wind turbine group as the maximum allowed output power;

[0015] S4, secondary correction of the coordination coefficient of part of the wind farm under extreme operating scenario;

[0016] S41, when there is at least one wind farm allocated with frequency modulation power exceeding the upper limit of the frequency modulation capacity of the wind farm under the current operating condition, the wind farm reaching the upper limit of the frequency modulation capacity outputs the maximum power, and uses the corrected coordination coefficient described in S33 to calculate the secondary allocated frequency modulation power and the relative safe operation margin of the wind farm not reaching the upper limit of the frequency modulation capacity;

[0017] S42, sort the relative safe operation margins in descending order, and select the wind farm corresponding to the safe operation margin in descending order as the standby station to bear the secondary allocated frequency modulation power, and calculate the secondary correction value of the coordination coefficient;

[0018] S43, compare the safe operation margin with the secondary correction value of the coordination coefficient, if the safe operation margin is greater than or equal to the secondary correction value of the coordination coefficient, output the secondary correction value of the coordination coefficient, otherwise, execute step S44;

[0019] S44, use step S33 to correct the secondary correction value of the coordination coefficient again, and compare the secondary correction value of the coordination coefficient corrected again with the safe operation margin, if the safe operation margin is greater than or equal to the secondary correction value of the coordination coefficient corrected again, output the secondary correction value of the coordination coefficient corrected again, otherwise, execute step S5;

[0020] S5, under the whole extreme scenario, all wind farms use the corrected coordination coefficient described in S33, and output according to the maximum allowed output power.

[0021] In actual frequency support control, the disturbance power is generally unknown, and the disturbance power can be estimated by the system average frequency change rate. Therefore, the adaptive cooperative frequency support control method considering the severity of disturbance events has the beneficial effects of:

[0022] 1. Extreme disturbance response capability: Through the scene (regular / extreme / full extreme) cooperative coefficient adjustment mechanism, the problem of simultaneous over-limit of multiple wind farms at large power shortage in traditional strategy is solved, and the risk of frequency collapse is reduced;

[0023] 2. Accurate evaluation of frequency regulation capability: The safety operation margin factor (SOF) is introduced to quantify the frequency regulation capability boundary of the wind turbine group, and the unreasonable wind turbine over-limit operation caused by the cooperative coefficient is avoided;

[0024] 3. Dynamic adaptive adjustment based on the severity of disturbance events: Based on the disturbance power estimation of the system average frequency change rate, the cooperative coefficient is corrected by cyclic evaluation in the regular scene, and the power is redistributed according to the relative safety margin in the extreme scene, so as to ensure efficient use of frequency regulation resources;

[0025] 4. System stability improvement: Through the safety margin constraint of the wind turbine group and the dynamic correction of the cooperative coefficient, the frequency secondary drop is reduced, and the safe operation of the power system is ensured.

[0026] The technical solutions of the present application will be further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The flow chart of the adaptive cooperative frequency support control method considering the severity of disturbance events described in the present application;

[0028] Figure 2 The improved 4-machine 13-node example topology structure of the verification example of the present application contains multiple wind farms;

[0029] Figure 3 The simulation results of load surge of 432MW under different criteria (WF1-[75, 75, 150]) described in the verification example of the present application, wherein (a) is the system frequency change curve, (b) is the total output change curve of each wind farm, and (c) is the wind turbine group speed result graph in each wind farm;

[0030] Figure 4 The simulation results of load surge of 432MW under different criteria (WF1-[25, 25, 250]) described in the verification example of the present application, wherein (a) is the system frequency change curve, (b) is the total output change curve of each wind farm, and (c) is the wind turbine group speed result graph in each wind farm. DETAILED DESCRIPTION

[0031] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present application and should not be used to limit the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout.

[0032] It should be noted that the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or server comprising a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0033] The embodiments of the present application are described in detail below with reference to the drawings.

[0034] As shown in Figure 1 The adaptive coordinated frequency support control method considering disturbance event severity includes the following steps:

[0035] S1, obtain the comprehensive frequency modulation margin factor proportion, capacity information, disturbance power and critical disturbance power of each wind farm, and determine the initial coordination coefficient based on the capacity proportion and the comprehensive frequency modulation margin factor;

[0036] The initial coordination coefficient expression of step S1 is as follows:

[0037]

[0038] In the formula, represents the initial coordination coefficient of the i th wind turbine group in the j th wind farm; OMF FM,j represents the j th comprehensive frequency modulation margin factor; C represents the coordination distribution coefficient of the wind farm cluster; represents the rated capacity of the wind turbine group in the j th wind farm; N sum represents the total number of wind farms participating in coordinated frequency modulation.

[0039] S2, based on the comparison result of the frequency modulation power allocated by each wind farm and the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, judge the operation scene;

[0040] When the frequency modulation power allocated to each wind farm is less than or equal to the sum of the maximum allowable output power of all wind turbines in the wind farm under physical constraints, it is determined to be a conventional scenario, and step S3 is performed;

[0041] When the frequency modulation power allocated to each wind farm is less than or equal to the sum of the maximum allowable output power of all wind turbines in the wind farm under physical constraints, it is determined to be a conventional scenario, and step S3 is performed;

[0042] When the frequency modulation power allocated to each wind farm is less than or equal to the sum of the maximum allowable output power of all wind turbines in the wind farm under physical constraints, it is determined to be a conventional scenario, and step S3 is performed;

[0043] S3, correction of the wind turbine group coordination coefficient in the conventional scenario;

[0044] S31, calculate the safe operation margin factor of each wind turbine group in the wind farm, and determine whether each wind turbine group has the ability to perform frequency modulation tasks according to the initial coordination coefficient according to the comparison result of the safe operation margin factor and the initial coordination coefficient. If yes, the current wind turbine group is determined to be an un-limited wind turbine group, and controlled according to the initial coordination coefficient; otherwise, the current wind turbine group is determined to be a limited wind turbine group, and step S32 is performed.

[0045] The safe operation margin factor calculation formula in step S31 is as follows:

[0046]

[0047] In the formula, represents the safe operation margin factor of the i th wind turbine group in the j th wind farm; represents the critical disturbance power of the i th wind turbine group in the j th wind farm corresponding to the maximum system frequency deviation; represents the expected minimum frequency deviation of the optimal system frequency trajectory;

[0048] and the disturbance power ΔP L is proportional to , and the ratio is set to κ, and formula (2) is rewritten as:

[0049]

[0050] In the formula, represents the maximum system frequency deviation of the i th wind turbine group in the j th wind farm;

[0051] When , the current wind turbine group is determined to be an un-limited wind turbine group; otherwise, the current wind turbine group is determined to be a limited wind turbine group.

[0052] S32, set the output power of one of the over-limit wind turbine groups to the maximum allowed output power, output the maximum allowed cooperation coefficient, and update the remaining frequency modulation power;

[0053] In step S32, the maximum allowed output power expression is as follows:

[0054]

[0055] In the formula, represents the maximum allowed output power of the i th wind turbine group in the j th wind farm; k F represents the feedback coefficient; H w represents the rotor inertia time constant of the wind turbine; ω r0 represents the rated speed of the rotor; s represents the complex frequency variable of Laplace transform; k m represents the mechanical power fitting coefficient; k t represents the electrical power fitting coefficient;

[0056] Maximum allowed cooperation coefficient The expression is as follows:

[0057]

[0058] The remaining frequency modulation power update expression is as follows:

[0059]

[0060] In which,

[0061]

[0062] In the formula, represents the updated remaining frequency modulation power of the j th wind farm in the conventional scenario; represents the capacity proportion of the remaining wind turbine group in the j th wind farm except the i th wind turbine group; represents the wind farm frequency modulation power instruction; represents the reference cooperation coefficient obtained by capacity allocation setting of each wind turbine group; represents the capacity proportion of the i th wind turbine group in the j th wind farm.

[0063] S33, the remaining over-limit wind turbine group re-allocates the remaining frequency modulation power according to the capacity proportion, and corrects the initial cooperation coefficient;

[0064] The initial cooperation coefficient correction formula in step S33 is as follows:

[0065]

[0066] In the formula, represents the corrected initial cooperation coefficient;

[0067] S34, judging the rationality of the modified initial synergy coefficient, if the modified initial synergy coefficient is rational, output the modified initial synergy coefficient, otherwise, return to step S32, set the output power of another ultra-limit wind turbine group as the maximum allowed output power;

[0068] In step S34, if the modified initial synergy coefficient is determined to be rational.

[0069] S4, secondary modification of the synergy coefficient of part of the wind farms in the extreme operating scenario;

[0070] S41, when there is at least one wind farm allocated with frequency modulation power exceeding the upper limit of the frequency modulation capacity of the wind farm under the current operating condition, the wind farm reaching the upper limit of the frequency modulation capacity outputs the maximum power, and the secondary allocated frequency modulation power and the relative safe operating margin of the wind farm not reaching the upper limit of the frequency modulation capacity are calculated using the modified synergy coefficient described in S33;

[0071] In step S41, whether there is at least one wind farm allocated with frequency modulation power exceeding the upper limit of the frequency modulation capacity of the wind farm under the current operating condition is judged using the following formula:

[0072]

[0073] Secondary allocated frequency modulation power The calculation formula is as follows:

[0074]

[0075] wherein,

[0076]

[0077] In the formula, represents the updated remaining frequency modulation power of the jth wind farm under the extreme scenario;

[0078] Relative safe operating margin The expression is as follows:

[0079]

[0080] In the formula, represents the number of remaining wind turbine groups in the jth wind farm except the ith wind turbine group.

[0081] S42, sort the relative safe operating margins in descending order, and select the wind farms corresponding to the safe operating margins in descending order as the backup stations to bear the secondary allocated frequency modulation power, and calculate the secondary modification value of the synergy coefficient;

[0082] In step S42, the frequency modulation power allocated to the preparation yard L is distributed is:

[0083]

[0084] Substitute formula (11) into formula (13) to obtain the quadratic correction value of the synergy coefficient

[0085] S43, compare the safe operation margin with the quadratic correction value of the synergy coefficient, if the safe operation margin is greater than or equal to the quadratic correction value of the synergy coefficient, output the quadratic correction value of the synergy coefficient, otherwise execute step S44;

[0086] S44, the quadratic correction value of the synergy coefficient is corrected again by step S33, and the quadratic correction value of the synergy coefficient is compared with the safe operation margin, if the safe operation margin is greater than or equal to the quadratic correction value of the synergy coefficient, output the quadratic correction value of the synergy coefficient, otherwise, execute step S5;

[0087] S5, in the full extreme scenario, all wind farms use the corrected synergy coefficient described in S33, and output according to the maximum allowed output power.

[0088] In actual frequency support control, the disturbance power is generally unknown, so the disturbance power can be estimated by the system average frequency change rate. According to the optimal system frequency trajectory, the system frequency value corresponding to the time when the wind power participates in frequency modulation is the lowest point of the expected frequency, and the disturbance power is proportional to the system average frequency change rate. Therefore, in step S31, the disturbance power ΔP L The expression is as follows:

[0089]

[0090] In the formula, ΔP L and respectively, the disturbance power under the optimal system frequency trajectory and the deviation of the lowest point of the expected frequency estimated according to the system average frequency change rate; f i is the system frequency detected by the i th wind farm; t0 is the time when the disturbance occurs; ΔT is the time period length for detecting the average frequency change rate; t A is the time when the wind power participates in frequency modulation.

[0091] Verification example

[0092] In this verification example, based on the actual frequency support control system as shown in Figure 2The improved 4-machine 13-node example with multiple wind farms is shown to verify the effectiveness of the application. The system contains 3 synchronous machines and three wind farms WF1, WF2, WF3, wherein wind farm WF1 and wind farm WF3 are replaced by 3 wind turbine groups, and wind farm WF2 is replaced by 2 wind turbine groups. And the number of units in the three wind farms is: 300, 200, 100, and the unit parameters are shown in Table 1.

[0093] Table 1 wind turbine parameters

[0094]

[0095] Table 2 wind speed and number of wind turbines of each wind farm

[0096]

[0097] The system is set to 2s, and a 432MW (24% of the total load) load surge event occurs, and the wind farm and the in-site unit power distribution is distributed according to the criteria shown in Table 3. The calculation results of the proportion of the frequency modulation power borne by each wind farm and the corresponding equivalent wind turbine coordination coefficient are shown in Table 4 and Table 5. It can be seen that part of the coordination coefficient (bold) is greater than the safety operation margin factor SOF, indicating that the corresponding equivalent wind turbine in the station will trigger the physical limit if it participates in frequency modulation according to the current distribution principle.

[0098] Table 3 description of different frequency modulation power distribution criteria

[0099]

[0100] Table 4 proportion of frequency modulation power borne by each wind farm under different distribution criteria

[0101] WF1 WF2 WF3 Criteria 1 0.5 0.333 0.167 Criteria 2 0.465 0.383 0.152 Criteria 3 0.514 0.270 0.216 Criteria 4 0.496 0.376 0.128

[0102] Table 5 equivalent wind turbine coordination coefficient (WF EQ1 , WF EQ2 and WF EQ3 represent the coordination coefficient of the first wind turbine group, the second wind turbine group and the third wind turbine group, respectively)

[0103]

[0104]

[0105] The simulation results are shown in Figure 3 , and it can be seen that in terms of safety, the coordination control strategy based on criterion 1 is used, and the WF EQ3The trigger speed protection control; the control strategy based on criterion 2 considers the rotor kinetic energy storage of each wind farm and wind turbine group in the field, and there is no frequency secondary drop phenomenon, but due to insufficient consideration of the frequency modulation capacity margin of the wind turbine, the equivalent wind turbine output power of some field stations triggers the frequency modulation power upper limit, and the frequency modulation capacity is limited; the control strategy based on criterion 3 considers the capacity and wind speed of each wind farm and wind turbine group in the field, but there is still an unreasonable power distribution situation, and WF EQ1 , WF EQ2 and WF EQ3 trigger the speed protection and frequency modulation power upper limit respectively. The adaptive adjustment criterion proposed in the application can ensure that each unit in the field station avoids triggering the physical limit. In addition, the wind turbine groups that may trigger the physical limit constraint under different criteria obtained by theoretical calculation are consistent with the simulation results, indicating that the rationality evaluation formula (formula (8)) proposed in the application can accurately judge the rationality of the coordination coefficient set according to different distribution criteria in advance.

[0106] As can be seen from Figure 3 , due to the difference in frequency modulation power distribution of the units in the field station under different criteria, the improvement effect on the system frequency is also different. The lowest point of the system frequency of criterion 1 is 49.489Hz, that of criterion 2 is 49.494Hz, that of criterion 3 is 49.505Hz, and that of the criterion 4 adopted in the application is improved to 49.513Hz, which is improved by 0.024Hz and 0.019Hz respectively relative to criterion 1 and criterion 2, and is improved by 0.008Hz relative to criterion 3. In summary, the frequency modulation effect and safety of the adaptive adjustment criterion proposed in the application are better.

[0107] Table 6 Maximum active power P we,max , electromagnetic torque T e,max and power P r,max of the machine side converter of the equivalent wind turbine under different criteria

[0108]

[0109] To further illustrate the superiority and robustness of the proposed criterion, the number of wind turbines under each wind speed in the test scene WF1 is modified to [25, 25, 250], and the operating condition of WF1 in this scene is more severe, mainly with low wind speed. When t=2s, the 432MW load surge event occurs, and the simulation results are shown in Figure 4 .

[0110] As can be seen from Figure 4It can be seen that, in terms of safety, the coordinated control based on other allocation criteria all have equivalent fan speed exceeding the safety threshold, resulting in frequency secondary drop phenomenon, while the criteria proposed in the application can ensure safe and stable operation of the unit. In terms of frequency modulation effect, the lowest system frequency of the criteria 1 is 49.455Hz, the criteria 2 is 49.442Hz, the criteria 3 is 49.482Hz, and the coordinated control strategy using the criteria proposed in the application can improve the lowest frequency point to 49.519Hz, which is 0.064Hz, 0.077Hz and 0.037Hz higher than the criteria 1, the criteria 2 and the criteria 3 respectively. It can be seen that the adaptive adjustment criteria proposed in the application can adjust the power allocation and set the coordination coefficient according to the operating condition of the wind farm, and fully exert the frequency modulation potential of the wind power to improve the system frequency response characteristics. The frequency improvement effect and safety are best in different scenarios, which verifies the effectiveness of the adaptive adjustment criteria and the coordinated control strategy proposed in the application.

[0111] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. An adaptive coordinated frequency support control method taking into account the severity of disturbance events, characterized in that: The method comprises the following steps: S1, obtaining the comprehensive frequency modulation margin factor proportion, capacity information, disturbance power and critical disturbance power of each wind farm, and determining an initial cooperation coefficient based on the capacity proportion and the comprehensive frequency modulation margin factor; S2, judging the operation scene based on the comparison result of the frequency modulation power allocated to each wind farm and the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints; When the frequency modulation power allocated to each wind farm is less than or equal to the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined to be a normal scene, and step S3 is executed; When the frequency modulation power allocated to part of the wind farms is greater than the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined to be an extreme operation scene, and step S4 is executed; When the frequency modulation power allocated to all wind farms is greater than the sum of the maximum allowed output power of all wind turbines in the wind farm under physical constraints, it is determined to be a full extreme scene, and step S5 is executed; S3, wind turbine group cooperation coefficient correction in normal scene; S31, calculating the safe operation margin factor of each wind turbine group in the wind farm, and judging whether each wind turbine group has the ability to perform frequency modulation task according to the comparison result of the safe operation margin factor and the initial cooperation coefficient, if yes, it is determined that the current wind turbine group is an un-limited wind turbine group, and the control is performed according to the initial cooperation coefficient, otherwise, it is determined that the current wind turbine group is a limited wind turbine group, and step S32 is executed; S32, setting the output power of one of the limited wind turbine groups to the maximum allowed output power, and outputting the maximum allowed cooperation coefficient, and updating the remaining frequency modulation power; S33, the remaining limited wind turbine groups re-distribute the remaining frequency modulation power according to the capacity proportion, and correct the initial cooperation coefficient; S34, judging the rationality of the corrected initial cooperation coefficient, if yes, output the corrected initial cooperation coefficient, otherwise, return to step S32, and set the output power of another limited wind turbine group to the maximum allowed output power; S4, secondary correction of the cooperation coefficient of part of the wind farms in the extreme operation scene; S41, when there is at least one wind farm whose allocated frequency modulation power exceeds the upper limit of the frequency modulation capacity of the wind farm under the current operation condition, the wind farm station reaching the upper limit of the frequency modulation capacity outputs the maximum power, and the secondary allocated frequency modulation power and the relative safe operation margin of the wind farm not reaching the upper limit of the frequency modulation capacity are calculated by using the corrected cooperation coefficient in S33; S42, sorting the relative safe operation margins in descending order, and selecting the wind farms corresponding to the safe operation margins in descending order as the standby stations to bear the secondary allocated frequency modulation power, and calculating the secondary correction value of the cooperation coefficient; S43, comparing the safe operation margin with the secondary correction value of the cooperation coefficient, if the safe operation margin is greater than or equal to the secondary correction value of the cooperation coefficient, output the secondary correction value of the cooperation coefficient, otherwise, execute step S44; S44, using step S33 to correct the cooperative coefficient secondary correction value again, and comparing the corrected cooperative coefficient secondary correction value with the safe operation margin, if the safe operation margin is greater than or equal to the corrected cooperative coefficient secondary correction value, outputting the corrected cooperative coefficient secondary correction value, otherwise, executing step S5; S5, in the full extreme scenario, all wind farms use the corrected cooperative coefficient in step S33, and output according to the maximum allowed output power.

2. The method of adaptive co-ordinated frequency support control considering severity of disturbance event according to claim 1, characterized in that: The initial cooperative coefficient expression in step S1 is as follows: In the formula, represents the initial coordination coefficient of the i th wind turbine group in the j th wind farm; OMF FM,j represents the j th comprehensive frequency modulation margin factor; C represents the coordination distribution coefficient of the wind farm cluster; represents the rated capacity of the wind turbine group in the j th wind farm; N sum represents the total number of wind farms participating in coordinated frequency modulation.

3. The method for adaptive coordinated frequency support control considering severity of disturbance event according to claim 2, characterized in that: The safe operation margin factor calculation formula in step S31 is as follows: In the formula, denotes the safety operation margin factor of the i th wind turbine group in the j th wind farm; denotes the critical disturbance power of the i th wind turbine group in the j th wind farm corresponding maximum system frequency deviation; denotes the expected frequency minimum point deviation of the optimal system frequency trajectory; and the disturbance power ΔP from the optimal system frequency trajectory L is proportional to and the disturbance power ΔP from the optimal system frequency trajectory is proportional to and the disturbance power ΔP from the optimal system frequency trajectory is proportional to and the disturbance power ΔP from the optimal system frequency trajectory is proportional to and the disturbance power ΔP from the optimal system frequency trajectory is proportional to and the disturbance power ΔP from the optimal In the formula, represents the maximum system frequency deviation of the jth wind farm group in the ith wind turbine. When the current fan group is determined as an un-overlimited fan group; otherwise, the current fan group is determined as an overlimited fan group.

4. The method for adaptive coordinated frequency support control considering severity of disturbance event according to claim 3, characterized in that: In step S32, the maximum allowed output power expression is as follows: wherein represents the maximum allowed output power of the jth wind turbine group in the ith wind farm; k F represents a feedback coefficient; H w represents the rotor inertia time constant of the wind turbine; ω r0 represents the rated rotor speed; s represents the complex frequency variable of the Laplace transform; k m represents the mechanical power fitting coefficient; k t represents the electrical power fitting coefficient; Maximum allowed synergy coefficient The expression is as follows: The remaining frequency modulation power update expression is as follows: Wherein, In the formula, represents the updated remaining frequency modulation power of the jth wind farm in the conventional scenario; represents the capacity proportion of the remaining wind turbine group in the jth wind farm except the ith wind turbine group; represents the wind farm frequency modulation power instruction; represents the reference coordination coefficient obtained by distributing and setting according to the capacity of each wind turbine group; represents the capacity proportion of the ith wind turbine group in the jth wind farm.

5. The method for adaptive co-ordinated frequency support control considering severity of disturbance event according to claim 4, characterized in that: The initial cooperative coefficient correction formula in step S33 is as follows: In the formula, represents the modified initial synergy coefficient; In step S34, if the modified initial correlation coefficient is determined to be reasonable.

6. The method for adaptive co-ordinated frequency support control considering severity of disturbance event according to claim 5, characterized in that: In step S41, whether there is at least one wind farm allocated to the frequency modulation power exceeding the upper limit of the frequency modulation capacity of the wind farm under the current operating condition is judged by using the following formula: Secondary allocation of frequency modulation power The calculation formula is as follows: Wherein, In the formula, represents the updated remaining frequency modulation power of the jth wind farm in an extreme scenario. Relative safe operating margin The expression is as follows: In the formula, represents the number of the remaining wind turbines in the jth wind farm except for the ith wind turbine group.

7. The method of adaptive co-ordinated frequency support control considering severity of disturbance events according to claim 6, characterized in that: In step S42, the frequency modulation power allocated to the preparation yard L is distributed is: Substituting equation (11) into equation (13) gives the quadratic correction to the synergy coefficient 8. The method for adaptive co-ordinated frequency support control considering severity of disturbance event according to claim 7, characterized in that: In step S31, the perturbation power ΔP under the optimal system frequency trajectory is calculated. L The expression is as follows: where ΔP L and are the disturbance power and the deviation of the minimum point of the expected frequency, respectively, under the optimal system frequency trajectory estimated according to the system average frequency change rate; f i is the system frequency detected by the ith wind farm; t0 is the time when the disturbance occurs; ΔT is the time period for detecting the average frequency change rate; t A is the time when the wind power participates in frequency regulation.

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