Wind power grid-connected system adaptive transient stability control method and device based on angular frequency offset, storage medium and equipment

Abstract

The application discloses a wind power grid-connected system adaptive transient stability control method and device based on angular frequency offset, a storage medium and equipment, obtains a virtual voltage through a negative feedback loop pre-set in a phase-locked loop according to an angular frequency offset in the system, adaptively controls the wind power grid-connected system based on the virtual voltage, remodels a phase-locked loop synchronization characteristic equation, and makes the inverter in the wind power grid-connected system keep synchronization with the power grid in a transient process. In different fault depths, the virtual voltage component can adjust a virtual electromagnetic torque of the wind power grid-connected system, remodel the phase-locked loop synchronization characteristic, adaptively offset the imbalance of the synchronization torque, make the wind power grid-connected system independently search for a balance point in the transient process, and effectively enhance the transient stability of the wind power grid-connected system. The application does not need to increase hardware equipment, is not limited by factors such as a disturbance type, system parameters and a converter capacity, and has strong adaptability.

Description

Technical Field

[0001] This invention relates to an adaptive transient stability control method, device, storage medium, and equipment for wind power grid-connected systems based on angular frequency offset, belonging to the field of transient stability technology in new energy power generation. Background Technology

[0002] With the rapid development of new energy power generation technologies, the installed capacity of new energy sources, represented by wind power, in the power system is constantly increasing. However, because the distribution of wind energy resources is opposite to the distribution of electricity load, wind power grid-connected systems require large-scale long-distance transmission, resulting in the grid exhibiting weakly synchronous grid characteristics. When a short-circuit fault occurs in the grid, the wind power grid-connected system may experience transient instability during low-voltage ride-through, which poses a serious threat to the safe and stable operation of the power system. Therefore, improving the transient stability of wind power grid-connected systems during grid faults is a crucial issue for current wind power development. However, existing control strategies are limited by converter capacity, making it difficult to solve the transient stability problem of wind power grid-connected systems during faults, and they cannot achieve adaptive adjustment under transient conditions. Summary of the Invention

[0003] The purpose of this invention is to provide an adaptive transient stability control method, device, storage medium, and equipment for wind power grid-connected systems based on angular frequency offset. This method does not require additional hardware; it only changes the control structure of the phase-locked loop (PLL) in the wind power grid-connected system by adding a negative feedback loop to the PLL. By negatively feeding the angular frequency offset to the PLL input, the synchronization characteristics are reshaped to improve the transient synchronization stability of the wind power grid-connected system during faults.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.

[0005] In a first aspect, the present invention provides an adaptive transient stability control method for a wind power grid-connected system based on angular frequency offset, comprising:

[0006] The angular frequency offset is obtained from the output angular frequency of the phase-locked loop in the wind power grid-connected system and the grid angular frequency.

[0007] Based on the angular frequency offset, a virtual voltage is obtained through a negative feedback loop pre-set in the phase-locked loop, and the virtual voltage is fed back to the input terminal of the phase-locked loop;

[0008] Based on the aforementioned virtual voltage adaptive control wind power grid-connected system, the phase-locked loop synchronization characteristic equation is reshaped to ensure that the inverter in the wind power grid-connected system remains synchronized with the grid during transient processes.

[0009] In conjunction with the first aspect, the negative feedback loop further includes an integral loop K / s, where K is a user-defined control parameter and s is a complex variable parameter.

[0010] In conjunction with the first aspect, further, the angular frequency offset Δω pll An additional virtual voltage ΔU is generated after passing through the integrator circuit of the negative feedback loop. tq and the virtual voltage ΔU tq Feedback is sent to the input of the phase-locked loop via the virtual voltage ΔU. tq Adaptive compensation of the error between the inverter output phase angle and the grid phase angle in a wind power grid-connected system.

[0011] In conjunction with the first aspect, the reshaped phase-locked loop synchronization characteristic equation is as follows:

[0012]

[0013] Among them, J v The moment of inertia coefficient, To achieve the virtual prime mover torque after adaptive control, T v To achieve the virtual electromagnetic torque after adaptive control, D v The damping coefficient is... This represents the proportional control coefficient of the phase-locked loop. This is the inductance value on the grid side. This is the d-axis current command value. These are the integral control coefficients for the phase-locked loop. This is the output angular frequency of the phase-locked loop. The angular frequency of the power grid. This is the q-axis current command value. For line resistance, This is the grid voltage. Let K be the angle difference between the grid voltage and the inverter output voltage, and K be the adaptive control parameter.

[0014] The reshaped phase-locked loop synchronization characteristic equation shows that the damping coefficient of the system is significantly increased after adopting adaptive transient control, resulting in stronger anti-interference and disturbance suppression capabilities, thereby improving the reliability and stability of the wind power grid-connected system. More importantly, the introduction of adaptive transient control allows the virtual electromagnetic torque Tv to adaptively adjust based on the angular frequency offset, enabling the system to automatically find a balanced operating point after experiencing large disturbances such as load changes and grid faults, maintaining synchronization with the grid.

[0015] In conjunction with the first aspect, further, obtaining the optimal value of the adaptive control parameter K through an iterative algorithm includes:

[0016] The adaptive control parameter K is initialized; the real-time power angle under the current adaptive control parameters is obtained by solving the second-order synchronization equation of the phase-locked loop using the MATLAB command "ode45". Determine the angle of work Does it exceed the set maximum overshoot? ;if If so, the adaptive control parameter will be increased by 0.01, and the real-time power angle will be recalculated based on the updated adaptive control parameter K until... ;if The iteration terminates, and the optimal value K of the adaptive control parameter K is output. cr .

[0017] The method of this invention can achieve better transient performance and asymptotic stability by designing and optimizing the adaptive control parameters.

[0018] Secondly, the present invention provides an adaptive transient stability control device for a wind power grid-connected system based on angular frequency offset, comprising:

[0019] The data acquisition module is used to obtain the angular frequency offset based on the angular frequency output by the phase-locked loop in the wind power grid-connected system and the grid angular frequency;

[0020] The negative feedback module is used to obtain a virtual voltage based on the angular frequency offset through a negative feedback loop pre-set in the phase-locked loop, and to feed the virtual voltage back to the input terminal of the phase-locked loop;

[0021] The transient stability control module is used to adaptively control the wind power grid-connected system based on the virtual voltage, reshape the phase-locked loop synchronization characteristic equation, and enable the inverter in the wind power grid-connected system to remain synchronized with the grid during transient processes.

[0022] In conjunction with the second aspect, the negative feedback loop further includes an integral loop K / s, where K is a user-defined control parameter and s is a complex variable parameter;

[0023] The negative feedback is specifically used to: adjust the angular frequency offset Δω pll An additional virtual voltage ΔU is generated after passing through the integrator circuit of the negative feedback loop. tq and the virtual voltage ΔU tq Feedback is sent to the input of the phase-locked loop.

[0024] In conjunction with the second aspect, furthermore, in the transient stability control module, the reshaped phase-locked loop synchronization characteristic equation is as follows:

[0025]

[0026] Among them, J v The moment of inertia coefficient, To achieve the virtual prime mover torque after adaptive control, T v To achieve the virtual electromagnetic torque after adaptive control, D v The damping coefficient is... This represents the proportional control coefficient of the phase-locked loop. This is the inductance value on the grid side. This is the d-axis current command value. These are the integral control coefficients for the phase-locked loop. This is the output angular frequency of the phase-locked loop. The angular frequency of the power grid. This is the q-axis current command value. For line resistance, This is the grid voltage. Let K be the angle difference between the grid voltage and the inverter output voltage, and K be the adaptive control parameter.

[0027] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the adaptive transient stability control method for wind power grid-connected systems as described in the first aspect.

[0028] Fourthly, the present invention provides an apparatus comprising:

[0029] Memory, used to store instructions;

[0030] A processor is configured to execute the instructions, causing the device to perform operations that implement the adaptive transient stability control method for wind power grid-connected systems as described in the first aspect.

[0031] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0032] This invention proposes an adaptive transient stability control method, device, storage medium, and equipment for wind power grid-connected systems based on angular frequency offset. A negative feedback loop is added to the phase-locked loop (PLL), and the angular frequency offset is used as the negative feedback quantity introduced into the PLL input terminal. Then, the wind power grid-connected system is adaptively adjusted according to the angular frequency offset, reshaping the dynamic characteristics of the PLL. Without increasing the hardware of the equipment, the inverter can remain synchronized with the grid during transient processes, ensuring the safe and stable operation of the power system. Attached Figure Description

[0033] Figure 1 The diagram shown is a schematic of a direct-drive wind power grid-connected system.

[0034] Figure 2 This is a schematic diagram of the wind power grid-connected system structure after adding a negative feedback loop in an embodiment of the present invention;

[0035] Figure 3 This is a flowchart illustrating the steps of the adaptive transient stability control method for wind power grid-connected systems based on angular frequency offset of the present invention.

[0036] Figure 4This is a schematic diagram showing the spatial positional relationship of the output power angle of the phase-locked loop in an embodiment of the present invention;

[0037] Figure 5 This is a phase trajectory diagram of a wind power grid-connected system employing adaptive control in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the parameter design process for the adaptive control parameter K in an embodiment of the present invention. Detailed Implementation

[0039] It should be noted that existing direct-drive wind power grid-connected systems, such as Figure 1 As shown, the system mainly includes a permanent magnet synchronous generator, a machine-side converter, a grid-connected inverter, and a power grid. A phase-locked loop (PLL) can be set between the grid-connected inverter and the power grid in the wind power grid-connected system to control system synchronization. However, when a short-circuit fault occurs in the power grid, the dynamic characteristics of the PLL will be disrupted, and the transient synchronization stability of the wind power grid-connected system during the fault cannot be maintained. Therefore, this invention adds a negative feedback loop between the input and output terminals of the PLL. The negative feedback loop introduces the system angular frequency offset into the input terminal of the PLL, reshaping the dynamic characteristics of the PLL and obtaining a wind power grid-connected system with adaptive transient stability control capability, such as... Figure 2 As shown. In Figure 1 , 2 Middle,U dc L is the inverter input voltage. f C is the inverter filter inductor. f For inverter filter capacitors, These are the voltages of phase a, phase b, and phase c, respectively. For line resistance, For grid-side inductance, This is the input voltage of the phase-locked loop. This represents the proportional control coefficient of the phase-locked loop. Here, s represents the integral control coefficient of the phase-locked loop, s represents the complex parameter, and Δω represents the integral control coefficient of the phase-locked loop. pll This is the angular frequency offset. The angular frequency of the power grid. The phase angle is the output phase angle of the phase-locked loop, K is the adaptive control parameter, and ΔU is the phase angle of the phase-locked loop. tq For Δω pll The virtual voltage generated after integration at K / s.

[0040] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0041] Example 1

[0042] This embodiment introduces an adaptive transient stability control method for wind power grid-connected systems based on angular frequency offset. Figure 2 Adaptive transient stability control is applied to the system structure, such as... Figure 3 As shown, it specifically includes:

[0043] Step A: Obtain the angular frequency offset based on the output angular frequency of the phase-locked loop in the wind power grid-connected system and the grid angular frequency.

[0044] Step B: Based on the angular frequency offset, obtain the virtual voltage through the negative feedback loop pre-set in the phase-locked loop, and feed the virtual voltage back to the input terminal of the phase-locked loop.

[0045] Step C: Based on the virtual voltage adaptive control of the wind power grid-connected system, reshape the phase-locked loop synchronization characteristic equation to ensure that the inverter in the wind power grid-connected system remains synchronized with the grid during transient processes.

[0046] In the dq coordinate system, the characteristic equation of the phase-locked loop is:

[0047] (1)

[0048] in, U is the output voltage of the grid-connected inverter in the wind power grid-connected system. t In the phase-locked loop coordinate system, the d-axis component For U t In the phase-locked loop coordinate system, the q-axis component For U t with U g The angle difference is called the work angle. The output current is represented by the d-axis component in the phase-locked loop coordinate system. This is the output angular frequency of the phase-locked loop. The output current is represented by the q-axis component in the phase-locked loop coordinate system.

[0049] In wind power grid-connected control, the bandwidth of the current inner loop is much higher than that of the phase-locked loop (PLL), and the dynamic response of the current inner loop is much faster than that of the PLL. Therefore, the influence of the current loop dynamics on the PLL can be ignored. Hence:

[0050] (2)

[0051] in, This is the d-axis current command value. This is the q-axis current command value.

[0052] To accurately describe the synchronization characteristics between the inverter and the power grid, this invention defines the power angle. This is the difference between the phase angle of the phase-locked loop output and the phase angle of the power grid. According to... Figure 4The spatial relationship of the output power angle of the phase-locked loop can be used to determine the power angle. The expression is:

[0053] (3)

[0054] Based on formulas (1)-(3), the synchronization equations for the phase-locked loop inverter without adding a negative feedback loop are obtained, and the specific expressions are as follows:

[0055] (4)

[0056] As can be seen from formula (4), the synchronization equation of a phase-locked loop inverter is similar to that of a synchronous generator phase-locked loop inverter. When a phase-locked loop synchronous inverter experiences a fault, it may exhibit oscillating behavior similar to rotor swaying, resulting in loss of synchronization with the power grid.

[0057] To address the aforementioned issues, this invention incorporates a negative feedback loop into the phase-locked loop (PLL). The negative feedback loop includes an integral loop K / s, through which the angular frequency offset can be introduced as a negative feedback quantity into the PLL input.

[0058] The basic idea of ​​this invention is that, under normal circumstances, the frequency and phase of the power grid should remain constant. At this time, the output angular frequency of the phase-locked loop (PLL) and the angular frequency of the power grid remain synchronized without deviation. If the power grid experiences a large disturbance, such as a short-circuit fault, the output angular frequency ω of the PLL will change. pll With the angular frequency ω of the power grid g An offset Δω will be generated between them. pll ,Δω pll = This leads to an error between the inverter output phase angle and the grid phase angle, causing transient instability in the wind power grid-connected system. To compensate for this phase error, the method of this invention uses the angular frequency offset Δω pll An additional virtual voltage ΔU is generated after passing through the integrator circuit. tq It is then negatively fed back to the input circuit of the phase-locked loop, with an additional virtual voltage ΔU. tq The inverter's output phase angle error can be adaptively offset based on the angular frequency deviation. The control strategy of this invention can adaptively adjust the balance of the virtual torque of the virtual synchronous generator, reshape the dynamic characteristics of the phase-locked loop, and enable the inverter to remain synchronized with the grid during transient processes.

[0059] In step C, using the above-mentioned adaptive transient control strategy, the reshaped phase-locked loop synchronization characteristic equation is shown below:

[0060] (5)

[0061] in, and Tv These are the virtual prime mover torque and the virtual electromagnetic torque after adaptive control, respectively. Maintaining their balance is crucial for maintaining transient synchronization stability. v and D v These are the rotational inertia coefficient and the damping coefficient, respectively.

[0062] Comparing formulas (4) and (5), it can be seen that the synchronization characteristics of the phase-locked loop have changed under the adaptive transient control strategy of this invention. The damping coefficient of the wind power grid-connected system is significantly increased, giving it stronger anti-interference and disturbance suppression capabilities, thereby improving the reliability and stability of the wind power grid-connected system. More importantly, the introduction of adaptive transient control increases the virtual electromagnetic torque T. v Based on adaptive adjustment of angular frequency offset, the system has the ability to automatically find a balanced operating point after being subjected to large disturbances such as load changes and power grid faults, thereby maintaining synchronization with the power grid.

[0063] In this embodiment of the invention, the effectiveness of the method of the present invention is further analyzed in conjunction with the following two situations:

[0064] 1) Virtual prime mover torque Virtual electromagnetic torque T v At that time, the wind power grid-connected system has excess torque, causing ω PLL >ω g At this time, the angular frequency offset Δω pll = If T is a positive number, v The virtual electromagnetic torque T will increase with the increase of angular frequency offset. Due to the effect of the integral controller in the negative feedback loop, as long as there is angular frequency deviation, the virtual electromagnetic torque T will increase. v It will keep increasing until the virtual prime mover torque... With virtual electromagnetic torque T v When equilibrium is reached, the system has a new equilibrium point, and the inverter remains synchronized with the power grid.

[0065] 2) Virtual prime mover torque Virtual electromagnetic torque T v At that time, the system has a torque deficit, causing ω PLL <ω g At this time, the angular frequency offset Δω pll = If it is negative, T v It will decrease as the angular frequency offset increases. Due to the effect of the integral controller in the negative feedback loop, as long as there is an angular frequency deviation, the virtual electromagnetic torque T will decrease. v It will continue to decrease until the virtual prime mover torque... With virtual electromagnetic torque T vWhen equilibrium is reached, the system has a new equilibrium point, and the inverter remains synchronized with the power grid.

[0066] Figure 5 The figure shows the phase trajectory of a wind power grid-connected system using adaptive control. As can be seen, the system can achieve stability under different control parameters. When a smaller control parameter (K=0.05) is used, the power angle will exceed the maximum allowable overshoot value and reach equilibrium point b after several periodic oscillations, resynchronizing with the grid. This is called non-asymptotic stability. When a larger control parameter (K=0.1) is used, the power angle does not exceed the maximum allowable value and converges directly to equilibrium point a. This is called asymptotic stability. Compared to asymptotic stability, non-asymptotic stability produces a larger power angle overshoot and requires more time to reach the equilibrium point.

[0067] To achieve better dynamic performance, this invention requires designing and optimizing the adaptive control parameter K in the negative feedback loop to achieve asymptotic stability. In practice, parameter K should not be too small, nor should it be too large, because an excessively large parameter K will lead to an increase in oscillation time. Therefore, the method of this invention needs to find a critical value for parameter K so that the system just reaches asymptotic stability.

[0068] In embodiments of the present invention, by means of... Figure 6 The iterative algorithm shown searches for the optimal design of the adaptive control parameter K:

[0069] The adaptive control parameter K is initialized to a small value (e.g., 0.01), i.e., K0. The power angle at different times is obtained by solving the second-order synchronization equation of the phase-locked loop using the MATLAB command "ode45". Determine the angle of work Does it exceed the set maximum overshoot? .like If so, proceed to the next iteration, increasing the adaptive control parameter by 0.01 in each iteration, and recalculating the real-time power angle; if If the iteration terminates, then K is the critical value, which is also the optimal value K in the method of this invention. cr .

[0070] Example 2:

[0071] Based on the same inventive concept as Embodiment 1, this embodiment introduces an adaptive transient stability control device for wind power grid-connected systems based on angular frequency offset, including a data acquisition module, a negative feedback module, and a transient stability control module.

[0072] The data acquisition module is mainly used to obtain the angular frequency offset based on the angular frequency output by the phase-locked loop in the wind power grid-connected system and the grid angular frequency.

[0073] The negative feedback module is mainly used to obtain a virtual voltage based on the angular frequency offset through a pre-set negative feedback loop in the phase-locked loop (PLL), and then feed the virtual voltage back to the PLL input. The negative feedback loop includes an integral loop K / s, where K is a user-defined control parameter and s is a complex variable parameter. Angular frequency offset Δω pll An additional virtual voltage ΔU can be generated after passing through the integrator circuit of the negative feedback loop. tq Additional virtual voltage ΔU tq It can adaptively compensate for the error between the inverter output phase angle and the grid phase angle based on the angular frequency deviation.

[0074] The transient stability control module is mainly used to adaptively control the wind power grid-connected system based on the virtual voltage, reshape the phase-locked loop synchronization characteristic equation, and enable the inverter in the wind power grid-connected system to remain synchronized with the grid during transient processes.

[0075] In the transient stability control module, the reshaped phase-locked loop synchronization characteristic equation is as follows:

[0076] (6)

[0077] Among them, J v The moment of inertia coefficient, To achieve the virtual prime mover torque after adaptive control, T v To achieve the virtual electromagnetic torque after adaptive control, D v The damping coefficient is... This represents the proportional control coefficient of the phase-locked loop. This is the inductance value on the grid side. This is the d-axis current command value. These are the integral control coefficients for the phase-locked loop. This is the output angular frequency of the phase-locked loop. The angular frequency of the power grid. This is the q-axis current command value. For line resistance, This is the grid voltage. Let K be the angle difference between the grid voltage and the inverter output voltage, and K be the adaptive control parameter.

[0078] Example 3:

[0079] Based on the same inventive concept as Embodiment 1, this embodiment introduces a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the adaptive transient stability control method for wind power grid-connected systems in Embodiment 1.

[0080] Example 4:

[0081] Based on the same inventive concept as Embodiment 1, this embodiment introduces a device, including: a memory for storing instructions; and a processor for executing the instructions, causing the device to perform operations that implement the adaptive transient stability control method for wind power grid-connected systems in Embodiment 1.

[0082] In summary, this invention addresses the problem that existing control strategies are limited by converter capacity and struggle to solve the transient stability problem of wind power grid-connected systems during faults. Based on a negative feedback loop, a new control strategy is proposed, which uses angular frequency offset as a negative feedback quantity introduced into the input of the phase-locked loop to reshape the dynamic characteristics of the phase-locked loop, thereby achieving synchronization between the inverter and the grid in the wind power grid-connected system during grid faults.

[0083] This invention possesses strong self-adaptive capabilities, unaffected by factors such as disturbance type, system parameters, and converter capacity, and requires no complex parameter adjustments. It is not only applicable to wind turbine current-source inverters but can also be widely applied to voltage-source inverters and multi-unit parallel systems.

[0084] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0085] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0086] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0088] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An adaptive transient stability control method for a wind power grid-connected system based on angular frequency offset, characterized in that, include: The angular frequency offset is obtained from the output angular frequency of the phase-locked loop in the wind power grid-connected system and the grid angular frequency. Based on the angular frequency offset, a virtual voltage is obtained through a negative feedback loop pre-set in the phase-locked loop, and the virtual voltage is fed back to the input terminal of the phase-locked loop; Based on the aforementioned virtual voltage adaptive control wind power grid-connected system, the phase-locked loop synchronization characteristic equation is reshaped to enable the inverter in the wind power grid-connected system to remain synchronized with the grid during transient processes. The negative feedback loop includes an integral loop K / s, where K is a user-defined control parameter and s is a complex variable parameter; angular frequency offset Δω pll An additional virtual voltage ΔU is generated after passing through the integrator circuit of the negative feedback loop. tq and the virtual voltage ΔU tq Feedback is sent to the input of the phase-locked loop via the virtual voltage ΔU. tq Adaptive compensation of the error between the inverter output phase angle and the grid phase angle in a wind power grid-connected system; The reshaped phase-locked loop synchronization characteristic equation is as follows: ； Among them, J v The moment of inertia coefficient, To achieve the virtual prime mover torque after adaptive control, T v To achieve the virtual electromagnetic torque after adaptive control, D v The damping coefficient is... This represents the proportional control coefficient of the phase-locked loop. This is the inductance value on the grid side. This is the d-axis current command value. These are the integral control coefficients for the phase-locked loop. This is the output angular frequency of the phase-locked loop. The angular frequency of the power grid. This is the q-axis current command value. For line resistance, This is the grid voltage. Let K be the angle difference between the grid voltage and the inverter output voltage, and K be the adaptive control parameter.

2. The adaptive transient stability control method for wind power grid-connected systems based on angular frequency offset according to claim 1, characterized in that, Obtaining the optimal value of the adaptive control parameter K through an iterative algorithm includes: The adaptive control parameter K is initialized; the real-time power angle under the current adaptive control parameters is obtained by solving the second-order synchronization equation of the phase-locked loop using the MATLAB command "ode45". Determine the angle of work Does it exceed the set maximum overshoot? ;if If so, the adaptive control parameter will be increased by 0.01, and the real-time power angle will be recalculated based on the updated adaptive control parameter K until... ;if The iteration terminates, and the optimal value K of the adaptive control parameter K is output. cr .

3. An adaptive transient stability control device for a wind power grid-connected system based on angular frequency offset, characterized in that, include: The data acquisition module is used to obtain the angular frequency offset based on the angular frequency output by the phase-locked loop in the wind power grid-connected system and the grid angular frequency; The negative feedback module is used to obtain a virtual voltage based on the angular frequency offset through a negative feedback loop pre-set in the phase-locked loop, and to feed the virtual voltage back to the input terminal of the phase-locked loop; The transient stability control module is used to adaptively control the wind power grid-connected system based on the virtual voltage, reshape the phase-locked loop synchronization characteristic equation, and enable the inverter in the wind power grid-connected system to remain synchronized with the grid during transient processes. The negative feedback loop includes an integral loop K / s, where K is a user-defined control parameter and s is a complex variable parameter; The negative feedback module is specifically used to: adjust the angular frequency offset Δω pll An additional virtual voltage ΔU is generated after passing through the integrator circuit of the negative feedback loop. tq and the virtual voltage ΔU tq Feedback is sent to the input of the phase-locked loop via the virtual voltage ΔU. tq Adaptive compensation of the error between the inverter output phase angle and the grid phase angle in a wind power grid-connected system; In the transient stability control module, the reshaped phase-locked loop synchronization characteristic equation is as follows: ； Among them, J v The moment of inertia coefficient, To achieve the virtual prime mover torque after adaptive control, T v To achieve the virtual electromagnetic torque after adaptive control, D v The damping coefficient is... This represents the proportional control coefficient of the phase-locked loop. This is the inductance value on the grid side. This is the d-axis current command value. These are the integral control coefficients for the phase-locked loop. This is the output angular frequency of the phase-locked loop. The angular frequency of the power grid. This is the q-axis current command value. For line resistance, This is the grid voltage. Let K be the angle difference between the grid voltage and the inverter output voltage, and K be the adaptive control parameter.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the adaptive transient stability control method for wind power grid-connected systems as described in any one of claims 1-2.

5. A computer device, characterized in that, include: Memory, used to store instructions; A processor is configured to execute the instructions, causing the device to perform operations that implement the adaptive transient stability control method for wind power grid-connected systems as described in any one of claims 1-2.

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