Primary frequency modulation relaxation control method and system for wind generating set

Abstract

The invention discloses a primary frequency modulation relaxation control method and system for a wind generating set, and the method comprises the steps: 1) detecting an externally input frequency modulation flag bit, calculating the active power variation if the frequency modulation flag bit needs to be entered, and sequentially executing the step 2) and the step 3); if not, the active power variable quantity is directly given by external input, and the step 4) is executed; (2) variable-speed variable-pitch control in a conventional mode is switched to variable-speed variable-pitch control in a frequency modulation mode; (3) judging whether frequency modulation is completed or whether the request flag bit exits, if so, executing the step (4), otherwise, still executing variable-speed variable-pitch control in the frequency modulation mode; and 4) executing variable-speed variable-pitch control in a conventional mode. The method can effectively restrain the problems of power drop and blade stall of primary frequency modulation of the wind power plant.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a primary frequency modulation relaxation control method, system, storage medium and computing device for a wind power generator set. Background Art

[0002] In recent years, wind power generation has become the main force in the renewable energy industry. With the large-scale grid connection of wind power, it has reached the stage where primary frequency regulation technology is adapted to wind turbine generator sets. The "Test Procedure for Grid Adaptability of Wind Turbine Generator Sets" (GB / T36994-2018) stipulates that wind turbine generator sets must have inertia response and primary frequency regulation capabilities, and must respond quickly to the grid frequency change rate and frequency deviation, participate in system frequency regulation, and support system frequency recovery. Due to the instability and volatility of wind energy and the large inertia of the unit itself, during the frequency regulation process, the power needs to reach the target value quickly, accurately, and stably, which is a great test for single-machine control. In addition, existing control technology means cannot effectively solve problems such as power drop and blade stall during primary frequency regulation. Therefore, an improved power control method is needed to meet the above and other requirements. Summary of the invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a relaxation control method for the primary frequency regulation of a wind turbine generator set. The method performs self-judgment based on the operating status of the set itself (information such as pitch angle and power). If the capacity limit is reached, the method will no longer respond quickly and will flexibly transition to a normal operating state, thereby effectively suppressing the power drop and blade stall problems of the primary frequency regulation of the wind farm.

[0004] A second object of the present invention is to provide a primary frequency modulation relaxation control system for a wind turbine generator set.

[0005] A third object of the present invention is to provide a storage medium.

[0006] A fourth object of the present invention is to provide a computing device.

[0007] The first object of the present invention is achieved by the following technical solution: A method for primary frequency modulation relaxation control of a wind turbine generator set, comprising the following steps:

[0008] 1) Detect the frequency modulation flag of the external input. If it is necessary to enter, calculate the active power change, and execute steps 2) and 3) in sequence; if it is not necessary to enter, the active power change is directly given by the external input, and execute step 4);

[0009] 2) The variable speed and pitch control in the normal mode is switched to the variable speed and pitch control in the frequency modulation mode;

[0010] 3) Determine whether the frequency modulation is completed or whether the request flag is exited. If so, execute step 4); otherwise, still execute the variable speed and variable pitch control in the frequency modulation mode;

[0011] 4) Execute the normal mode of variable speed and variable pitch control.

[0012] Further, in step 1), the active power change is calculated as follows:

[0013]

[0014] Where: ΔP t is the change in active power of the wind farm; K f is the active frequency modulation coefficient; Δf is the power system frequency deviation; f N is the rated frequency of the power system; P t is the active power of the wind farm.

[0015] Further, in step 2), compared with the variable speed and pitch control in the conventional mode, the variable speed and pitch control in the frequency modulation mode is different in the calculation method of the speed setting value and the output lower limit. The variable speed and pitch control in the frequency modulation mode includes torque control and pitch control, which are as follows:

[0016] a. The torque control process during frequency modulation is as follows: the measured speed of the generator is filtered and compared with the set speed, the deviation obtained by comparison is used for PI control with the torque offset, and the output is obtained after limiting; when the unit changes from normal mode to frequency modulation mode, the calculation method of the speed set value and the torque lower limit is adjusted, as follows:

[0017] ①Switch of speed setting value:

[0018] The speed setting value is switched by adjusting the gain value KoptFre of the unit operation, and the calculation formula is as follows:

[0019] KoptFre=Kopt×MovAv(FCKoptRatio,Step)

[0020] In the formula, Kopt represents the theoretical optimal gain value, MovAv represents the sliding average filter, FCKoptRatio represents the scaling factor, and Step represents the step size;

[0021] When frequency modulation is required, the gain value KoptFre of the unit operation is scaled based on the theoretical optimal gain value Kopt, and the scaling factor FCKoptRatio is processed by average moving filter; compared with the normal mode, the speed setting value of the low power range (0-2500kW) in the frequency modulation mode is higher, aiming to ensure that the unit stores sufficient rotational inertia;

[0022] ② Switch the calculation method of the torque lower limit:

[0023] The calculation process of the torque lower limit output during frequency modulation is as follows: when the rated flag is true, the torque lower limit TorqueMin is calculated based on the deviation PitchDiff between the current pitch angle and the minimum pitch angle limit, the set margin value PitchMargin and the torque demand increment TorqueDemand. The calculation formula is as follows:

[0024]

[0025] In the formula, TorqueMinLast is the torque lower limit output of the previous cycle, and the torque demand increment TorqueDemand is actually the difference between the power setting and the actual speed ratio of the previous and next two cycles; when the rated flag is false, the torque lower limit transitions to the optimal torque TorqueOpt within the set time with the current lower limit value; the rated flag is whether the current power reaches 90% of the set power, which is true if it reaches, otherwise false;

[0026] The optimal torque TorqueOpt is calculated as follows:

[0027] TorqueOpt=Kopt×GenSpeed 2

[0028] Where, GenSpeed ​​is the generator speed;

[0029] b. The variable pitch control process during frequency modulation is as follows: the measured speed of the generator is compared with the set speed after filtering, the deviation obtained by comparison is used for PID control with the variable pitch offset, and the given blade angle setting output is obtained after limiting; when the unit changes from normal mode to frequency modulation mode, the calculation method of adjusting the speed setting value and the variable pitch lower limit is as follows:

[0030] ①Switch of speed setting value:

[0031] The mapping relationship between the set speed and power is consistent with the above torque control;

[0032] ② Switch the calculation method of the lower limit of pitch change:

[0033] Reduce the rate limit of the pitch angle and adjust the value to half of the original value to allow the unit to absorb wind energy as quickly as possible.

[0034] Further, regarding whether the frequency modulation in step 3) is completed, that is, whether the unit speed enters the set speed deviation band. Let P1, P2, and P3 represent the power equivalent curves, that is, the power values on the same curve are equal, and there is a relationship P1 < P2 < P3. Let A1, B1, A2, and B2 represent the speed and torque values of the unit operation. When the active power change is positive, assume the unit operates at a limited power at point A1, that is, the power value of P1. Now, when the grid frequency is disturbed downward and the power needs to reach the power value of P2, through the switching of torque control, the unit quickly runs from point A1 to point B1. Subsequently, the unit operates on the equal-power curve P2. If the speed enters the set speed deviation band through pitch PID (Proportional-Integral-Derivative) control, the torque PI (Proportional-Integral) control can take over, and the fluctuation amplitudes of the unit speed and torque at the takeover time can be adjusted by setting the size of the deviation band. When the active power change is negative, assume the unit operates at a limited power at point A2, that is, the power value of P3. Now, when the grid frequency is disturbed upward and the power needs to reach the power value of P2, through the switching of torque control, the unit quickly runs from point A2 to point B2. Subsequently, the unit operates on the equal-power curve P2. If the speed enters the set speed deviation band through pitch PID (Proportional-Integral-Derivative) control, the torque PI (Proportional-Integral) control can take over.

[0035] Further, in step 4), when it is detected that the frequency modulation flag bit input externally is FALSE or the frequency modulation execution is completed, the variable speed and variable pitch control is adjusted to the normal mode.

[0036] The second object of the present invention is achieved by the following technical solution: A primary frequency modulation relaxation control system for a wind turbine generator set is used to implement the above-mentioned primary frequency modulation relaxation control method for a wind turbine generator set, and includes:

[0037] A first judgment module, which is used to detect the externally input frequency modulation flag bit. If it is necessary to enter, it calculates the active power change amount and sequentially executes the frequency modulation control module and the second judgment module; otherwise, the active power change amount is directly given externally, and the normal execution module is executed;

[0038] A frequency modulation control module, which is used to switch the variable speed and variable pitch control in the normal mode to the variable speed and variable pitch control in the frequency modulation mode;

[0039] A second judgment module, which judges whether the frequency modulation is completed or whether the request flag bit exits. If so, the normal execution module is executed; otherwise, the variable speed and variable pitch control in the frequency modulation mode is still executed;

[0040] A normal execution module, which is used to execute the variable speed and variable pitch control in the normal mode.

[0041] The third object of the present invention is achieved through the following technical solution: a storage medium stores a program, and when the program is executed by a processor, the above-mentioned primary frequency modulation relaxation control method of the wind turbine generator set is implemented.

[0042] The fourth objective of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, wherein when the processor executes the program stored in the memory, the above-mentioned primary frequency modulation relaxation control method of the wind turbine generator set is implemented.

[0043] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0044] 1. In the unit performance curve, the operating point during frequency modulation is biased to the right of the optimal operating point. On the one hand, it can ensure that it stores enough kinetic energy. On the other hand, if the wind speed drops, the operating point can be closer to the optimal operating point instead of gradually deviating from it, thus avoiding the occurrence of unit stall.

[0045] 2. Compared with the conventional mode, the variable speed and variable pitch control in the frequency modulation mode adjusts the speed setting value, pitch angle, and the calculation method of the lower limit of the torque output, so that the unit can make a transient response of frequency modulation according to the target output requirements and its own conditions.

[0046] 3. Adaptive control is performed based on the unit's own operating status, such as pitch angle, power and other information. For example, under the current wind conditions, the output limit has been reached and the unit will no longer forcibly respond to the frequency regulation requirements. It will flexibly transition to normal operating status to avoid a sharp drop in power due to overdraft.

[0047] 4. The present invention can effectively suppress the power drop and blade stall problems of primary frequency modulation in wind farms. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Flow chart of the method of the present invention.

[0049] Figure 2 This is the torque control logic flow chart.

[0050] Figure 3 This is the logic flow chart of pitch control.

[0051] Figure 4 This is the calculation flow chart of the minimum torque limit during primary frequency modulation.

[0052] Figure 5 This is a mapping diagram of power-speed setting values ​​during frequency modulation.

[0053] Figure 6 This is the speed-torque curve of the unit during frequency modulation.

[0054] Figure 7Schematic diagram of the system of the present invention. DETAILED DESCRIPTION

[0055] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0056] Example 1

[0057] like Figure 1 As shown, this embodiment discloses a primary frequency modulation relaxation control method for a wind turbine generator set, and the specific situation is as follows:

[0058] 1) Detect the frequency modulation flag of the external input. If it is necessary to enter, calculate the active power change, and execute steps 2) and 3) in sequence; if it is not necessary to enter, the active power change is directly given by the external input, and execute step 4); wherein, the active power change is calculated as follows:

[0059]

[0060] Where: ΔP t is the change in active power of the wind farm, in MW; K f is the active frequency modulation coefficient; Δf is the frequency deviation of the power system, in Hz; f N is the rated frequency of the power system, in Hz; P t is the active power of the wind farm, in MW.

[0061] 2) The variable speed and pitch control in the normal mode is switched to the variable speed and pitch control in the frequency modulation mode;

[0062] Compared with the variable speed and pitch control in the conventional mode, the variable speed and pitch control in the frequency modulation mode is different in the calculation method of the speed setting value and the output lower limit. The variable speed and pitch control in the frequency modulation mode includes torque control and pitch control, as follows:

[0063] a. Figure 2 As shown in the figure, the torque control process during frequency modulation is as follows: the measured speed of the generator is filtered and compared with the set speed, the deviation obtained by comparison is used for PI control with the torque offset, and the output is obtained after limiting; when the unit changes from normal mode to frequency modulation mode, the calculation method of the speed set value and the torque lower limit is adjusted, as follows:

[0064] ①Switch of speed setting value:

[0065] The speed setting value is switched by adjusting the gain value KoptFre of the unit operation, and the calculation formula is as follows:

[0066] KoptFre=Kopt×MovAv(FCKoptRatio,Step)

[0067] In the formula, Kopt represents the theoretical optimal gain value, MovAv represents the sliding average filter, FCKoptRatio represents the scaling factor, and Step represents the step size, which is generally 0.01;

[0068] When frequency modulation is required, the unit operation gain value KoptFre is scaled based on the theoretical optimal gain value Kopt, and the scaling factor FCKoptRatio is processed by average moving filter; Figure 5 As shown, compared with the normal mode, the speed setting value of the low power range (0-2500kW) in the frequency modulation mode is higher, in order to ensure that the unit stores sufficient rotational inertia;

[0069] ② Switch the calculation method of the torque lower limit:

[0070] like Figure 4 As shown in the figure, the calculation process of the torque lower limit output during frequency modulation is as follows: when the rated flag is true, the torque lower limit TorqueMin is calculated based on the deviation PitchDiff between the current pitch angle and the minimum pitch angle limit, the set margin value PitchMargin and the torque demand increment TorqueDemand. The calculation formula is as follows:

[0071]

[0072] In the formula, TorqueMinLast is the torque lower limit output of the previous cycle, and the torque demand increment TorqueDemand is actually the difference between the power setting and the actual speed ratio of the previous and next two cycles; when the rated flag is false, the torque lower limit transitions to the optimal torque TorqueOpt within the set time with the current lower limit value; the rated flag is whether the current power reaches 90% of the set power, which is true if it reaches, otherwise false;

[0073] The optimal torque TorqueOpt is calculated as follows:

[0074] TorqueOpt=Kopt×GenSpeed 2

[0075] Where, GenSpeed ​​is the generator speed;

[0076] b. Figure 3 As shown in the figure, the variable pitch control process during frequency modulation is as follows: the measured speed of the generator is compared with the set speed after filtering, the deviation obtained by comparison is PID controlled with the variable pitch offset, and the given blade angle setting output is obtained after limiting; when the unit changes from the normal mode to the frequency modulation mode, the calculation method of adjusting the speed setting value and the variable pitch lower limit is as follows:

[0077] ①Switch of speed setting value:

[0078] Set the mapping relationship between the set rotational speed and power to be consistent with the above torque control, and according to Figure 5 the following

[0079] ② Calculation method switching of the pitch lower limit:

[0080] Reduce the rate limit of the pitch angle, and adjust the value to half of the original value to enable the unit to absorb wind energy as soon as possible.

[0081] 3) Determine whether the frequency modulation is completed or whether the request flag bit exits. If so, execute step 4). Otherwise, still execute the variable speed and variable pitch control in the frequency modulation mode;

[0082] Regarding whether the frequency modulation in step 3) is completed, that is, whether the unit rotational speed enters the set rotational speed deviation band, Figure 6 is the rotational speed - torque curve diagram of the unit during frequency modulation. Let P1, P2, P3, P4, P5 represent the power equal - value curves, that is, the power values on the same curve are equal, and there is a relationship P1 < P2 < P3 < P4 < P5. Let A1, B1, C1, A2, B2, C2 represent the rotational speed and torque values of the unit operation. When the change in active power is positive, assume the unit operates at a limited power at point A1, that is, the power value of P1. Now, when the grid frequency is disturbed downward and the power needs to reach the P2 power value, through the switching of torque control, the unit quickly runs from point A1 to point B1. Subsequently, the unit operates on the equal - power curve P2. If the rotational speed enters the set rotational speed deviation band through pitch PID (Proportional - Integral - Derivative) control, as shown at point C1, the torque PI (Proportional - Integral) control can take over, and the fluctuation amplitude of the rotational speed and torque of the unit at the takeover time can be adjusted by setting the size of the deviation band; when the change in active power is negative, assume the unit operates at a limited power at point A2, that is, the power value of P3. Now, when the grid frequency is disturbed upward and the power needs to reach the P2 power value, through the switching of torque control, the unit quickly runs from point A2 to point B2. Subsequently, the unit operates on the equal - power curve P2. If the rotational speed enters the set rotational speed deviation band through pitch PID (Proportional - Integral - Derivative) control, as shown at point C2, the torque PI (Proportional - Integral) control can take over.

[0083] 4) Execute the variable speed and variable pitch control in the normal mode;

[0084] When it is detected that the externally input frequency modulation flag bit is FALSE or the frequency modulation execution is completed, the variable speed and variable pitch control is adjusted to the normal mode.

[0085] Embodiment 2

[0086] This embodiment discloses a primary frequency modulation relaxation control system for a wind turbine generator set, which is used to implement the primary frequency modulation relaxation control method of the wind turbine generator set described in Embodiment 1, as Figure 7 shown, including:

[0087] The first judgment module is used to detect the frequency modulation flag bit of the external input, and if it is necessary to enter, the active power change is calculated, and the frequency modulation control module and the second judgment module are executed in sequence; otherwise, the active power change is directly given by the outside, and the conventional execution module is executed;

[0088] A frequency modulation control module, used for switching the variable speed and pitch control in the conventional mode to the variable speed and pitch control in the frequency modulation mode;

[0089] The second judgment module judges whether the frequency modulation is completed or whether the request flag is exited. If so, the conventional execution module is executed; otherwise, the variable speed and variable pitch control in the frequency modulation mode is still executed;

[0090] The conventional execution module is used to execute the variable speed and variable pitch control in the conventional mode.

[0091] Example 3

[0092] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the primary frequency modulation relaxation control method of the wind turbine generator set described in Embodiment 1 is implemented.

[0093] The storage medium in this embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.

[0094] Example 4

[0095] This embodiment discloses a computing device, including a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the primary frequency modulation relaxation control method of the wind turbine generator set described in Embodiment 1 is implemented.

[0096] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0097] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A primary frequency modulation relaxation control method for a wind turbine generator set, characterized in that: The following steps are involved: 1) Detect the frequency modulation flag of the external input. If it is necessary to enter, calculate the active power change, and execute steps 2) and 3) in sequence; if it is not necessary to enter, the active power change is directly given by the external input, and execute step 4); 2) The variable speed and pitch control in the normal mode is switched to the variable speed and pitch control in the frequency modulation mode; 3) Determine whether the frequency modulation is completed or whether the request flag is exited. If so, execute step 4); otherwise, still execute the variable speed and variable pitch control in the frequency modulation mode; 4) Execute the normal mode of variable speed and variable pitch control.

2. A wind turbine primary frequency modulation relaxation control method according to claim 1, characterized in that: In step 1), the active power change is calculated as follows: Where: ΔP t is the change in active power of the wind farm; K f is the active frequency modulation coefficient; Δf is the frequency deviation of the power system; f N is the rated frequency of the power system; Pt is the active power of the wind farm.

3. A wind turbine primary frequency modulation relaxation control method according to claim 1, characterized in that: In step 2), compared with the variable speed and pitch control in the conventional mode, the variable speed and pitch control in the frequency modulation mode is different in the calculation method of the speed setting value and the output lower limit. The variable speed and pitch control in the frequency modulation mode includes torque control and pitch control, as follows: a. The torque control process during frequency modulation is as follows: the measured speed of the generator is filtered and compared with the set speed, the deviation obtained by comparison is used for PI control with the torque offset, and the output is obtained after limiting; when the unit changes from normal mode to frequency modulation mode, the calculation method of the speed set value and the torque lower limit is adjusted, as follows: ①Switch of speed setting value: The speed setting value is switched by adjusting the gain value KoptFre of the unit operation, and the calculation formula is as follows: KoptFre=Kopt×MovAv(FCKoptRatio,Step) In the formula, Kopt represents the theoretical optimal gain value, MovAv represents the sliding average filter, FCKoptRatio represents the scaling factor, and Step represents the step size; When frequency modulation is required, the unit operating gain value KoptFre is scaled based on the theoretical optimal gain value Kopt, and the scaling factor FCKoptRatio is processed by average moving filter; Compared with the normal mode, the speed setting value of the low power range, i.e. 0-2500kW, in the frequency modulation mode is higher, in order to ensure that the unit stores sufficient rotational inertia; ② Switch the calculation method of the torque lower limit: The calculation process of the torque lower limit output during frequency modulation is as follows: when the rated flag is true, the torque lower limit TorqueMin is calculated based on the deviation PitchDiff between the current pitch angle and the minimum pitch angle limit, the set margin value PitchMargin and the torque demand increment TorqueDemand. The calculation formula is as follows: In the formula, TorqueMinLast is the torque lower limit output of the previous cycle, and the torque demand increment TorqueDemand is actually the difference between the power setting and the actual speed ratio of the previous and next two cycles; when the rated flag is false, the torque lower limit transitions to the optimal torque TorqueOpt within the set time with the current lower limit value; the rated flag is whether the current power reaches 90% of the set power, which is true if it reaches, otherwise false; The optimal torque TorqueOpt is calculated as follows: TorqueOpt=Kopt×GenSpeed 2 Where, GenSpeed ​​is the generator speed; b. The pitch control process during frequency modulation is as follows: The generator measures the rotational speed, filters it, and compares it with the set rotational speed. The deviation obtained from the comparison is subjected to PID control with a pitch offset, and after amplitude limiting, the set output of the blade angle is obtained. When the unit changes from the normal mode to the frequency modulation mode, the calculation methods of the rotational speed set value and the pitch lower limit are adjusted as follows: ① Switching of the rotational speed set value: The mapping relationship between the set rotational speed and power is the same as that of the above torque control; ② Switching of the calculation method of the pitch lower limit: The rate limit for reducing the pitch angle is adjusted to half of the original value to enable the unit to absorb wind energy as soon as possible.

4. A wind turbine primary frequency modulation relaxation control method according to claim 1, characterized in that: Regarding whether the frequency modulation in step 3) is completed, that is, whether the rotational speed of the unit enters the set rotational speed deviation band, let P1, P2, and P3 represent the power equivalent curves, that is, the power values on the same curve are equal, and there is a relationship of P1 < P2 < P3. Let A1, B1, A2, and B2 represent the rotational speed and torque values of the unit during operation. When the change in active power is positive, assume the unit operates at a limited power at point A1, that is, the power value of P1. Now, when the grid frequency is disturbed downward, the power needs to reach the power value of P2. Through the switching of torque control, the unit quickly runs from point A1 to point B1. Subsequently, the unit operates on the constant power curve P2. If the rotational speed enters the set rotational speed deviation band through pitch PID (Proportional-Integral-Derivative) control, the torque PI (Proportional-Integral) control can take over, and the fluctuation amplitude of the rotational speed and torque of the unit at the takeover time can be adjusted by setting the size of the deviation band; when the change in active power is negative, assume the unit operates at a limited power at point A2, that is, the power value of P3. Now, when the grid frequency is disturbed upward, the power needs to reach the power value of P2. Through the switching of torque control, the unit quickly runs from point A2 to point B2. Subsequently, the unit operates on the constant power curve P2. If the rotational speed enters the set rotational speed deviation band through pitch PID control, the torque PI control can take over.

5. A wind turbine primary frequency modulation relaxation control method according to claim 1, characterized in that: In step 4), when it is detected that the externally input frequency modulation flag bit is FALSE or the frequency modulation execution is completed, the variable speed and variable pitch control is adjusted to the normal mode.

6. A primary frequency modulation relaxation control system for a wind turbine generator set, characterized in that: A program for implementing the primary frequency modulation relaxation control method of the wind turbine generator set according to any one of claims 1 to 5, comprising: A first judgment module for detecting the externally input frequency modulation flag bit. If it is necessary to enter, it calculates the change in active power and sequentially executes the frequency modulation control module and the second judgment module; otherwise, the change in active power is directly given externally, and the normal execution module is executed; A frequency modulation control module for switching the variable speed and variable pitch control in the normal mode to the variable speed and variable pitch control in the frequency modulation mode; A second judgment module for judging whether the frequency modulation is completed or whether the request flag bit exits. If so, the normal execution module is executed; otherwise, the variable speed and variable pitch control in the frequency modulation mode is still executed; A normal execution module for executing the variable speed and variable pitch control in the normal mode.

7. A storage medium storing a program, characterized in that: When the program is executed by a processor, it implements the primary frequency modulation relaxation control method of the wind turbine generator set according to any one of claims 1 to 5.

8. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the primary frequency modulation relaxation control method of the wind turbine generator set according to any one of claims 1 to 5 is implemented.

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