Oscillation suppression method and device of wind storage combined grid-connected system and control equipment

Abstract

The invention provides an oscillation suppression method and device of a wind storage combined grid-connected system and control equipment, and relates to the technical field of power system control. According to the specific technical scheme, two stable controllers are additionally arranged in the wind storage combined grid-connected system and act on a wind turbine generator system and an energy storage system respectively, and the total equivalent damping of the wind storage combined grid-connected system is controlled to be larger than a preset value by setting stable control gains of the wind turbine generator system and the energy storage system. Therefore, the wind storage combined grid-connected system is prevented from oscillation and instability; by adopting the scheme, when the wind-storage combined grid-connected system has an oscillation trend, unbalanced torque in the system can be counteracted through the stability controller, low-frequency oscillation is effectively suppressed, the operation stability and reliability of the wind-storage combined grid-connected system in a complex power grid environment are improved, and the risk of off-network is reduced.

Description

Technical Field

[0001] This application relates to the field of power system control technology, and in particular to an oscillation suppression method, apparatus and control equipment for a wind-storage combined grid-connected system. Background Technology

[0002] With global ecological and environmental issues becoming increasingly prominent, wind power generation has experienced rapid development worldwide due to its significant advantages such as abundant resources, environmental friendliness, and renewability. To improve the flexibility and controllability of wind power grid connection, wind-storage integrated grid connection systems have emerged and become the mainstream trend in current new energy development.

[0003] However, while wind-storage combined systems enhance system flexibility, they also introduce new stability issues. Wind turbines and energy storage systems are typically connected to the grid via power electronic converters. Their complex dynamic characteristics interact adversely with grid impedance, resulting in the loss of the inertial response and damping characteristics of traditional synchronous generators. When a wind-storage combined system is connected to the grid, the system's damping distribution changes significantly, easily leading to stability problems such as low-frequency oscillations. Summary of the Invention

[0004] This application provides a method, apparatus, and control device for oscillation suppression in a wind-storage combined grid-connected system. Two stability controllers are added to the system, acting on the wind turbine system and the energy storage system respectively. By adjusting the stability control gains of the wind turbine system and the energy storage system, the total equivalent damping of the combined system is controlled, thereby suppressing oscillations. This solution can achieve oscillation suppression in the combined wind-storage grid-connected system, improving its operational stability and reliability in complex grid environments and reducing the risk of grid disconnection.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: Firstly, a method for suppressing oscillations in a wind-storage grid-connected system is provided. This system includes a wind turbine system and an energy storage system connected in parallel. Unlike conventional wind-storage grid-connected systems, the system provided in this application adds two stability controllers, one for the wind turbine system and the other for the energy storage system. Specifically, the first stability controller operates on the wind turbine system, and the second stability controller operates on the energy storage system. The input signal to the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilizer is the DC voltage U of the energy storage system. esThe first and second stabilizing controllers perform preset processing on the input signals to obtain the output signals. This preset processing may include high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilizing controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, and the output signal of the second stabilizing controller acts on the outer loop of the DC voltage of the energy storage converter of the energy storage system.

[0006] In this method, the stability control gain K1 of the wind turbine system and the stability control gain K2 of the energy storage system can be adjusted until the total equivalent damping D of the wind-storage grid-connected system is greater than a preset value. The preset value is greater than zero. If D is less than zero, the wind-storage grid-connected system will oscillate and become unstable. D = D A +D B +D C K1 affects the first equivalent damping D A K2 affects the second equivalent damping D B .

[0007] Among them, the first equivalent damping D A The self-damping coefficient of the wind turbine system under the action of the first stabilizer controller reflects the ability of the wind turbine system's closed-loop control to suppress voltage fluctuations under the action of the first stabilizer controller. The second equivalent damping coefficient is D. B This represents the self-damping coefficient of the energy storage system under the action of the second stabilizing controller, reflecting the ability of the energy storage system's closed-loop control to suppress voltage fluctuations under the action of the second stabilizing controller. Coupling damping D C This is the mutual damping coefficient between the wind turbine system and the energy storage system.

[0008] In this scheme, a stability controller is added to the wind turbine system and the energy storage system respectively. By adjusting the stability control gain of the wind turbine system and the energy storage system, the total equivalent damping of the wind-storage grid-connected system can be adjusted until the total equivalent damping is greater than a preset value, thus ensuring that the wind-storage grid-connected system will not oscillate and become unstable. In other words, when the wind-storage grid-connected system shows an oscillating tendency, the stability controller can offset the unbalanced torque in the system, fully utilize the rapid response advantage of the energy storage system, and effectively suppress low-frequency oscillations. This achieves oscillation suppression of the wind-storage grid-connected system, improves the operational stability and reliability of the wind-storage grid-connected system in complex grid environments, and reduces the risk of grid disconnection.

[0009] In one possible implementation of the first aspect, the method further includes: obtaining the first transfer function G. s1 Second transfer function G s2 ; Obtain the third transfer function G A Fourth transfer function G B and the fifth transfer function G C ; Using GA +G s1 =D A + (K) A / s), for G A +G s1 Decompose to obtain D A Using G B +G s2 =D B + (K) B / s), for G B +G s2 Decompose to obtain D B Using G C =D C + (K) C / s), for G C Decompose to obtain D C .

[0010] Among them, G s1 This reflects the control characteristics of the first stable controller during the dynamic response process. s2 This reflects the control characteristics of the second stabilizing controller during the dynamic response process. A This reflects the control characteristics of the wind turbine system under the action of the first stabilizing controller during its dynamic response process in cooperation with the energy storage system. B This reflects the control characteristics of the energy storage system during its dynamic response process in cooperation with the wind turbine system under the action of the second stabilizing controller. C This reflects the coupling relationship between the wind turbine system and the energy storage system during collaborative operation. Here, s is the Laplace operator; K... A K B K C This is the synchronization coefficient. K1 affects D. A Specifically, K1 affects G s1 K2 affects D B Specifically, K2 affects G s2 .

[0011] In this wind-storage integrated grid-connected system, the transfer functions of the control characteristics of each component (such as the first stability controller, the second stability controller, the wind turbine system, and the energy storage system) during the operation of the system, as well as the transfer function reflecting the coupling relationship between the turbine system and the energy storage system during collaborative operation, are related to the equivalent damping of the corresponding components. In this scheme, the equivalent damping D of the turbine system in the wind-storage integrated grid-connected system can be calculated using the transfer functions reflecting the control characteristics of each component (such as the first stability controller, the second stability controller, the wind turbine system, and the energy storage system) during the operation of the system, and the transfer functions reflecting the coupling relationship between the turbine system and the energy storage system during collaborative operation.A The equivalent damping D of the energy storage system B and coupling damping D C .

[0012] In another possible implementation of the first aspect, the above-mentioned acquisition of the first transfer function G s1 Second transfer function G s2 The third transfer function G A Fourth transfer function G B and the fifth transfer function G C This includes: based on the DC voltage dynamic characteristics of wind turbine systems and energy storage systems, abstracting the wind turbine systems and energy storage systems into single-input single-output systems, and obtaining G. s1 G s2 G A G B and G C .

[0013] Based on the dynamic DC voltage characteristics of the wind turbine system and energy storage system, the complex wind-storage grid-connected system is simplified into a single-input single-output wind turbine system and a single-input single-output energy storage system. Simultaneously, the interaction between the wind turbine system and the energy storage system is simplified, with the interaction relationship between them represented by a single-input single-output system. This modeling and simplification reduces the system's complexity and facilitates quantitative data-driven assessment of system stability.

[0014] In another possible implementation of the first aspect, based on the dynamic DC voltage characteristics of the wind turbine system and the energy storage system, the wind turbine system and the energy storage system are abstracted into a single-input single-output system, resulting in G. s1 G s2 G A G B and G C This can include: constructing a damping torque model for a wind-storage grid-connected system based on the DC voltage dynamic characteristics of the wind turbine system and the energy storage system; and using a modular analysis approach, abstracting the wind turbine system and the energy storage system into a single-input single-output system in the damping torque model to obtain G. s1 G s2 G A G B and G C .

[0015] By constructing a damping torque model for a wind-storage grid-connected system, we can accurately quantify the damping torque of each system, including the wind turbine system, the energy storage system, and the interaction between the wind turbine system and the energy storage system. This will clearly reveal the variation law of the damping characteristics of each system. By analyzing the damping changes of the system, we can determine whether there is an oscillation risk in the DC voltage loop of the wind turbine system and the energy storage system.

[0016] In another possible implementation of the first aspect, the aforementioned G A G B and G C They are respectively: , , ; Where C1 is the DC capacitor of the wind turbine system, C2 is the DC capacitor of the energy storage system; s is the Laplace operator; G a G represents the self-damping transfer function formed by the dynamic adjustment of the wind turbine system's power and voltage under the action of the first stabilizer controller, reflecting the ability of the wind turbine system's closed-loop control to suppress internal disturbances under the action of the first stabilizer controller; d G is the self-damping transfer function of the energy storage system under the action of the second stability controller; c G represents the mutual damping transfer function of the wind turbine system to the energy storage system, reflecting the dynamic impact of DC voltage fluctuations in the wind turbine system on the energy storage system. b PI is the mutual damping transfer function of the energy storage system on the wind turbine system, reflecting the reaction of the energy storage system on the wind turbine system. A For the PI parameters of the DC voltage loop of the wind turbine system, I w1 U represents the steady-state current value of the turbine-side converter in the wind turbine system under the action of the first stability controller. dcw1 PI represents the steady-state value of the DC voltage of the wind turbine system under the action of the first stabilizer controller. B For the PI parameters of the energy storage system, U esw2 This represents the steady-state value of the power supply voltage of the energy storage system under the action of the second stabilization controller.

[0017] This method establishes mathematical models of the transfer functions of each component in a wind-storage grid-connected system, including the wind turbine system, the energy storage system, and the interaction between the wind turbine system and the energy storage system. This allows the parameters of each component to be obtained both theoretically and through actual measurement, facilitating a quantitative assessment of system stability.

[0018] In another possible implementation of the first aspect, the aforementioned K1 influences G. s1 K2 affects G s2 Specifically: , ; Among them, T1, T2 and T3 are all time constants, and T1, T2 and T3 are set based on the potential oscillation frequency of the wind-storage integrated grid-connected system.

[0019] In this method, the high-pass filter in the DC blocking stage acts as a filter, processing the signal and selectively allowing voltage signals of specific frequency bands to pass through, thus eliminating the influence of steady-state signals on the stabilizer. The phase compensation stage compensates for the phase deviation between the controller's input and output signals, and the control gain stage amplifies and adjusts the signal. K1 affects G. s1 K2 affects G s2 When a small signal disturbance occurs, the control gain K is adjusted. 1、 K2 influences the system function G of the stability controller. s1 G s2 This can enhance the damping coefficient of wind turbine systems and energy storage systems, thereby suppressing oscillations in wind-storage grid-connected systems.

[0020] Secondly, an oscillation suppression device for a wind-storage combined grid-connected system is provided. This device includes a wind turbine system and an energy storage system connected in parallel. Furthermore, the wind-storage combined grid-connected system also includes a first stability controller and a second stability controller. The input signal of the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilizer is the DC voltage U of the energy storage system. es The first and second stabilizing controllers perform preset processing on the input signals to obtain the output signals. This preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilizing controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, while the output signal of the second stabilizing controller acts on the outer loop of the DC voltage controlled by the energy storage converter of the energy storage system. The device includes a tuning module.

[0021] The tuning module is used to tune the stability control gain K1 of the wind turbine system and the stability control gain K2 of the energy storage system until the total equivalent damping D of the wind-storage grid-connected system is greater than a preset value. The preset value is greater than zero. When D is less than zero, the wind-storage grid-connected system will oscillate and become unstable. D=D A +D B +D C K1 affects the first equivalent damping D A K2 affects the second equivalent damping D B Among them, D A D B and D CFor a detailed introduction, please refer to the first aspect and its possible implementation methods, which will not be repeated here.

[0022] Thirdly, a control device for a wind-storage combined grid-connected system is provided. This control device includes a wind turbine system and an energy storage system connected in parallel. Furthermore, the control device also includes a first stability controller and a second stability controller. The input signal to the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilizer is the DC voltage U of the energy storage system. es The first and second stabilizing controllers perform preset processing on the input signals to obtain the output signals. This preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilizing controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, while the output signal of the second stabilizing controller acts on the outer loop of the DC voltage controlled by the energy storage converter of the energy storage system.

[0023] The control device includes a memory and at least one processor, as well as related devices / equipment for combined wind and energy storage grid connection. The memory is communicatively connected to the processor and stores computer program code, including computer instructions. When the processor executes the computer instructions, it causes the control device to perform a method as described in the first aspect and any of its possible implementations.

[0024] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer instructions. When these computer instructions are executed by a processor, they are used to implement the method as described in the first aspect and any possible implementation thereof.

[0025] Fifthly, embodiments of this application provide a computer program product that, when running on a computer or executed by the computer's processor, implements the method described in the first aspect and any possible design of the method.

[0026] It is understood that the beneficial effects achieved by the oscillation suppression device of the wind-storage combined grid-connected system described in the second aspect above, the control equipment of the wind-storage combined grid-connected system described in the third aspect, the computer-readable storage medium described in the fourth aspect, and the computer program product described in the fifth aspect can be referred to as the beneficial effects in the first aspect and any possible implementation thereof, and will not be repeated here. Attached Figure Description

[0027] Figure 1 A schematic diagram of the system architecture of a wind-storage integrated grid-connected system provided in this application embodiment; Figure 2A schematic diagram of another wind-storage integrated grid-connected system provided in this application embodiment; Figure 3 This application provides a schematic diagram of the internal structure of a wind turbine system stability controller. Figure 4 A schematic diagram of the internal structure of an energy storage system stability controller provided in an embodiment of this application; Figure 5A A flowchart illustrating an oscillation suppression method for a wind-storage integrated grid-connected system provided in this application embodiment; Figure 5B Flowchart of another oscillation suppression method for a wind-storage combined grid-connected system provided in this application embodiment; Figure 6 A schematic diagram of the damping torque model of a wind-storage combined grid-connected system provided in this application embodiment; Figure 7 A graph showing the damping coefficient of a wind-storage combined grid-connected system as a function of the grid-connected power of the wind turbine system, provided for embodiments of this application; Figure 8A Flowchart of another oscillation suppression method for a wind-storage combined grid-connected system provided in this application embodiment; Figure 8B Flowchart of another oscillation suppression method for a wind-storage combined grid-connected system provided in this application embodiment; Figure 9 A schematic diagram of the damping torque model of another wind-storage combined grid-connected system provided in this application embodiment; Figure 10 A schematic diagram of an oscillation suppression device for a wind-storage combined grid-connected system provided in this application embodiment; Figure 11 A schematic diagram of another oscillation suppression device for a combined wind and energy storage grid-connected system provided in this application embodiment; Figure 12 This is a schematic diagram of the internal structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0028] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this embodiment, unless otherwise stated, "a plurality of" means two or more.

[0029] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0030] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0031] To improve the stability of wind turbine grid connection, energy storage systems are often introduced for coordinated control, achieving smooth output of wind power. Please refer to [reference needed]. Figure 1 This illustrates a schematic diagram of the system architecture of a wind-storage integrated grid-connected system provided in an embodiment of this application. Figure 1 As shown, the wind-storage grid-connected system 100 may include a wind turbine system 110 and an energy storage system 120 connected in parallel.

[0032] The wind turbine system 110 and the energy storage system 120 are connected in parallel. The wind turbine system 110 includes a permanent magnet synchronous generator, a machine-side converter, and a grid-side converter. The permanent magnet synchronous generator converts wind energy into frequency-converted AC power, which is first rectified into DC power by the machine-side converter and then converted into grid-compatible AC power by the grid-side converter. The energy storage system 120 includes bidirectional converters (electromagnetic-side converter and grid-side converter) to realize the charging and discharging control of the energy storage system and regulate the power flow of the energy storage system.

[0033] The wind turbine system 110 converts wind energy into electrical energy to supply the power grid, while the energy storage system 120 absorbs excess power or supplements grid deficits in real time. When wind speed is high and the power generation exceeds the grid's capacity or actual demand, the energy storage system can store the excess electrical energy through battery charging. Conversely, when wind speed weakens and power generation is insufficient, the energy storage system releases the stored electrical energy to supplement the grid, thus smoothing the power output curve of wind power. This wind-storage combined grid-connected system 100 effectively solves the stability and reliability issues arising from wind power grid connection and improves power quality.

[0034] The aforementioned wind turbine system 110 is connected to the power grid via a power electronic converter. This connection method causes the rotor speed to decouple from the grid frequency, resulting in the loss of the inertial response and damping characteristics of a traditional synchronous generator. When the wind turbine system is connected to the grid, the system's damping distribution changes significantly, easily leading to stability problems such as low-frequency oscillations.

[0035] In conventional techniques, detailed models encompassing wind turbines, energy storage systems, and the power grid are constructed. Time-domain simulations are then used to observe the system's dynamic response to disturbances, thereby analyzing the damping characteristics of the wind-storage integrated grid-connected system. Simultaneously, regarding oscillation suppression, eigenvalue analysis and other methods are employed to reveal stability issues arising from the coupling between the wind turbine system's converter control strategy and the energy storage system. Virtual impedance or adaptive damping controllers are introduced into the converter control loop to reshape the system's impedance characteristics.

[0036] However, there are many limitations in the research techniques for the stability of wind-storage integrated grid-connected systems. Traditional methods for evaluating the damping and stability of wind turbines are insufficient to deeply and accurately analyze the damping characteristics of wind turbines under complex operating conditions, and cannot provide sufficiently detailed and accurate data support for the formulation of oscillation suppression strategies. In terms of oscillation suppression, focusing only on the adjustment of the wind turbine's own control parameters ignores the complex interaction between the wind turbine, the energy storage system, and the power grid, resulting in poor oscillation suppression effects.

[0037] To address the aforementioned issues, this application's embodiments introduce two stability controllers into the wind-storage integrated grid-connected system to suppress oscillations and enhance its operational stability. Please refer to... Figure 2 This illustrates a schematic diagram of the system architecture of another wind-storage combined grid-connected system provided in an embodiment of this application.

[0038] like Figure 2 As shown, the wind-storage grid-connected system 200 includes a wind turbine system 210 and an energy storage system 220. Unlike the wind-storage grid-connected system 100, as... Figure 2 As shown, the wind-storage grid-connected system 200 also includes a first stability controller 211 and a second stability controller 221.

[0039] The first stability controller 211 operates on the wind turbine system 210. For example... Figure 2 As shown, the input terminal of the first stability controller 211 is connected to the turbine-side converter of the wind turbine system 210, that is, the input signal of the first stability controller 211 is the DC voltage U of the wind turbine system 210. dc The output terminal of the first stabilization controller 211 is connected to the grid-side converter of the wind turbine system 210, that is, the output signal of the first stabilization controller 211 acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system 210.

[0040] The second stability controller 221 operates on the energy storage system 220. For example... Figure 2As shown, the input terminal of the second stability controller 221 is connected to the battery-side converter of the energy storage system 220, that is, the input signal of the second stability controller 221 is the DC voltage U of the energy storage system 220. es The output terminal of the second stability controller 221 is connected to the grid-side converter of the energy storage system 220, that is, the output signal of the second stability controller 221 acts on the DC voltage outer loop of the grid-side converter of the energy storage system 220.

[0041] In this embodiment, the first stabilizing controller 211 and the second stabilizing controller 221 perform preset processing on the input signal to obtain the output signal. This preset processing may include high-pass filtering with DC blocking, phase compensation, and gain amplification.

[0042] For example, Figure 3 This diagram illustrates the internal structure of a wind turbine system stability controller according to an embodiment of this application, corresponding to the first stability controller. Figure 3 As shown, the first control stabilization controller 211 may include a high-pass filter 212, a phase compensation circuit 213, and a gain amplification circuit 214. Figure 4 This diagram illustrates the internal structure of an energy storage system stability controller according to an embodiment of this application, corresponding to a second control stability controller, such as... Figure 4 As shown, the second stabilization controller 221 may include a high-pass filter 222, a phase compensation stage 223, and a gain amplification stage 224.

[0043] In this embodiment, the first stabilization controller 211 and the second stabilization controller 221 are used to suppress oscillations in the wind-storage combined grid-connected system. Specifically, by implementing this scheme, the total equivalent damping D of the wind-storage combined grid-connected system 200 can be controlled to be greater than a preset value, which is greater than zero, by adjusting the stability control gain of the wind turbine system 210 and the energy storage system 220. When the total equivalent damping D of the wind-storage combined grid-connected system 200 is less than zero, the wind-storage combined grid-connected system 200 will oscillate and become unstable. When the total equivalent damping D of the wind-storage combined grid-connected system 200 is greater than the preset value, oscillation and instability of the wind-storage combined grid-connected system 200 can be avoided. In summary, this scheme can suppress oscillations in the wind-storage combined grid-connected system 200.

[0044] The methods of this application are described below with reference to the accompanying drawings and specific embodiments.

[0045] This application provides an embodiment of a method for suppressing oscillations in a wind-storage combined grid-connected system, applicable to... Figure 2 The wind-storage combined grid-connected system 200 is shown. The entity executing the oscillation suppression method of this wind-storage combined grid-connected system can be the oscillation suppression device of the wind-storage combined grid-connected system, or it can be the control equipment of the wind-storage combined grid-connected system; this application does not limit this. For example... Figure 5AAs shown, the method in this application embodiment may include S501-S503.

[0046] S501, setting the stability control gain K1 of the wind turbine system 210 and the stability control gain K2 of the energy storage system 220; K1 affects D A K2 affects D B .

[0047] Among them, D A Called the first equivalent damping, it is the self-damping coefficient of the wind turbine system 210, reflecting the ability of the wind turbine system 210's closed-loop control to suppress voltage fluctuations. B It is called the second equivalent damping, which is the self-damping coefficient of the energy storage system 220, reflecting the ability of the closed-loop control of the energy storage system 220 to suppress voltage fluctuations.

[0048] It should be noted that the above-mentioned first equivalent damping D A It is the equivalent damping of the wind turbine system 210 under the action of the first stability controller 211. That is to say, D A This is the self-damping coefficient of the wind turbine system 210 under the action of the first stabilizer controller 211, reflecting the ability of the wind turbine system 210 to suppress voltage fluctuations through its own closed-loop control under the action of the first stabilizer controller 211. The aforementioned second equivalent damping D... B It is the equivalent damping of the energy storage system 220 under the action of the second stability controller 221. That is to say, D B It is the self-damping coefficient of the energy storage system 220 under the action of the second stabilizing controller 221, reflecting the ability of the energy storage system 220 to suppress voltage fluctuations through its own closed-loop control under the action of the second stabilizing controller 221.

[0049] Among them, K1 affects the first equivalent damping D A K2 affects the second equivalent damping D B It should be understood that, with the addition of the first stabilizer 211 and the second stabilizer 221, the first stabilizer 211 and the second stabilizer 221 can respectively control the DC voltage U of the wind turbine system 210. dc and the DC voltage U of the energy storage system 220 es The signal is then processed. Specifically, it first passes through a high-pass filter in the DC blocking stage. The high-pass filter acts as a filter, selectively allowing voltage signals of specific frequency bands to pass through, thus eliminating the influence of steady-state signals on the stabilizer. Next, the signal is processed through a phase compensation stage to compensate for the phase deviation between the controller's input and output signals. Further amplification and adjustment are performed through control gain, and finally, the signals are superimposed onto the outer loops of the DC voltage control for the wind turbine system's 210 grid-side converter and the energy storage system's 220 grid-side converter.

[0050] Thus, the equivalent damping D of the wind turbine system 210 A (i.e., the first equivalent damping D) A The equivalent damping of wind turbine system 210 differs from that of wind turbine system 110. The equivalent damping D of wind turbine system 210... A It will also be affected by the first stability controller 211. Similarly, the equivalent damping D of the energy storage system 220... B (i.e., the second equivalent damping D) B The equivalent damping of energy storage system 220 differs from that of energy storage system 120. The equivalent damping D of energy storage system 220... B It is also affected by the second stabilization controller 221. Specifically, the high-pass filter attenuates low-frequency signals in advance, which is equivalent to adding positive damping at high frequencies and suppressing low-frequency oscillations. The phase compensation stage generates a positive damping torque opposite to the negative damping source, offsetting its adverse effects and causing the overall damping to recover. The gain amplification stage also increases the damping coefficient, accelerating the oscillation decay rate. Therefore, the equivalent damping of the wind turbine system 210 and energy storage system 220 under the action of the stabilization controller will be higher than that of the wind turbine system 110 and energy storage system 120.

[0051] S502, Calculate the total equivalent damping D of the wind-storage integrated grid-connected system 200, D=D A +D B +D C .

[0052] S503. Determine whether the total equivalent damping D is greater than the preset value.

[0053] The preset value of the total equivalent damping D is greater than zero, which can ensure that the wind-storage grid-connected system 200 will not oscillate and become unstable.

[0054] After S503, if the total equivalent damping D is less than or equal to the preset value, then S501 continues; if the total equivalent damping D is greater than the preset value, then the oscillation suppression process ends. For example, the preset value can be 0.25. Of course, the preset value can also be any value greater than zero. For example, the preset value can also be any value such as 0.26, 0.27, 0.3, or 0.4. This preset value can be obtained by testing the critical total equivalent damping for oscillation instability in the wind-storage integrated grid-connected system 200.

[0055] Among them, such as Figure 5B As shown, after S501 and before S502, the method of this application embodiment may also include S500.

[0056] S500, Obtain the first equivalent damping D A Second equivalent damping D B and coupling damping D C .

[0057] Among them, DC This represents the mutual damping coefficient between the wind turbine system 210 and the energy storage system 220. Note that the coupling damping D... C It is generated by the interaction between the wind turbine system 210 under the action of the first stabilizing controller 211 and the energy storage system 220 under the action of the second stabilizing controller 221. However, its value can be equal to or equivalent to the coupling damping generated by the interaction between the wind turbine system 110 and the energy storage system 120 when not under the action of the stabilizing controller. That is, the coupling damping between the wind turbine system and the energy storage system remains unchanged before and after the addition of the stabilizing controller in the wind-storage grid-connected system.

[0058] For ease of understanding, the embodiments of this application are described here first. Figure 1 The equivalent damping of the wind turbine system 110 and the energy storage system 120 in the wind-storage grid-connected system 100 (without a stability controller) is shown below; further details are provided. Figure 2 The equivalent damping of the wind turbine system 210 and the energy storage system 220 in the wind-storage grid-connected system 200 (after adding the first stability controller 211 and the second stability controller 221).

[0059] (1) The equivalent damping of the wind turbine system 110 (referred to as equivalent damping D) a The equivalent damping of the energy storage system 120 (referred to as equivalent damping D) b The coupling damping D of the wind turbine system 110 and the energy storage system 120 c .

[0060] Among them, the equivalent damping D is obtained. a Equivalent damping D b and coupling damping D C This can include S601-S602.

[0061] S601: Based on the DC voltage dynamic characteristics of the wind turbine system 110 and the energy storage system 120, the wind turbine system 110 and the energy storage system 120 are abstracted as a single-input single-output system, resulting in G. 1 A G 1 B and G 1 C .

[0062] Among them, G 1 A G represents the input-output transfer function of the wind turbine system 110, reflecting the control characteristics of the wind turbine system 110 during dynamic response, including the combined effects of converter control and power regulation; 1 B G represents the input-output transfer function of the energy storage system 120, reflecting the converter control and power supply charging and discharging process of the energy storage system 120 in dynamic response;1 C It is the input-output transfer function for the interaction between the wind turbine system 110 and the energy storage system 120, reflecting the coupling relationship between the wind turbine system 110 and the energy storage system 120 during operation.

[0063] For example, S601 above may include S601a-S601b. S601a: Constructing a damping torque model for the wind-storage combined grid-connected system 100; S601b: Using a modular analysis approach, abstracting the wind turbine system 110 and energy storage system 120 into a single-input single-output system in the damping torque model, obtaining G... 1 A G 1 B and G 1 C Please refer to this. Figure 6 This illustration shows a schematic diagram of the damping torque model of a wind-storage combined grid-connected system 100 provided in an embodiment of this application. Figure 6 As shown, in the damping torque model 600, the wind turbine system 110 and energy storage system 120 of the wind-storage grid-connected system 100 can be abstracted as single-input single-out (SISO) systems, resulting in G. 1 A G 1 B and G 1 C .

[0064] Among them, G 1 A G 1 B and G 1 C This can be expressed through the individual damping transfer functions, mutual damping transfer functions, and other relevant devices or parameters in the damping torque model 600. Specifically: ; ; .

[0065] Where C1 is the DC capacitor of the wind turbine system 110, C2 is the DC capacitor of the energy storage system 120, and s is the Laplace operator.

[0066] G 1 a G represents the self-damping transfer function formed by the dynamic regulation of power and voltage of the wind turbine system 110, reflecting the ability of the closed-loop control of the wind turbine system 110 to suppress internal disturbances. 1d G is the self-damping transfer function of energy storage system 120; c G represents the mutual damping transfer function of the wind turbine system 110 to the energy storage system 120, reflecting the dynamic impact of DC voltage fluctuations in the wind turbine system 110 on the energy storage system 120. b This is the mutual damping transfer function of the energy storage system 120 to the wind turbine system 110, reflecting the reaction of the energy storage system 120 to the wind turbine system 110.

[0067] PI A These are the PI parameters for the DC voltage loop of the wind turbine system 110. 1 w1 This represents the steady-state current value of the generator-side converter in wind turbine system 110. 1 dcw1 PI is the steady-state value of the DC voltage of the wind turbine system 110. B For the PI parameters of the energy storage system 120, U 1 esw2 This is the steady-state value of the power supply voltage for the energy storage system 120.

[0068] The construction of this damping torque model not only simplifies the complex wind-storage grid-connected system into a single-input, single-output wind turbine system and a single-input, single-output energy storage system, but also simplifies the interaction between the wind turbine system and the energy storage system, representing their interaction relationship as a single-input, single-output system. This model construction and simplification allows the parameters of each component to be both theoretically derived and obtained through actual measurements, facilitating quantitative evaluation of the system's stability through data.

[0069] S602: Adopts G 1 A =D a + (K) A / s), for G 1 A Decompose to obtain D A ; Using G 1 B =D b + (K) B / s), for G 1 B Decompose to obtain D b ; Using G 1 C =D c + (K) C / s), for G 1 C Decompose to obtain D C .

[0070] According to the above formula, we know that: Da =G 1 A -(K A / s), D b =G 1 B -(K B / s), D c =G 1 C -(K C / s).

[0071] Where s is the Laplace operator; D a The self-damping coefficient of the wind turbine system 110, i.e., the equivalent damping D. a D b The self-damping coefficient of the energy storage system 120 is called the equivalent damping D. b D c The mutual damping coefficient, i.e., the coupling damping D, is generated by the interaction between the wind turbine system 110 and the energy storage system 120. c K A K B K C This is the synchronization coefficient.

[0072] The equivalent damping of the wind-storage grid-connected system 100 can be decomposed into three key parts: the first being the self-damping coefficient D of the wind turbine system 110. a This reflects the ability of the wind turbine system's closed-loop control to suppress voltage fluctuations; secondly, it reflects the self-damping coefficient D of the energy storage system. b The third aspect is the mutual damping coefficient D between the wind turbine system 110 and the energy storage system 120, which reflects the ability of the energy storage system 120 to suppress voltage fluctuations through its own closed-loop control. c The transfer function originates from the interaction between the wind turbine system 110 and the energy storage system 120. Therefore, the total damping D′ of the wind-storage combined grid-connected system 100 is: .

[0073] When the total damping of the wind-storage grid-connected system is less than 0, the system will oscillate and become unstable. Figure 7 This diagram illustrates the damping coefficient of a wind-storage combined grid-connected system 100 provided in an embodiment of this application, as a function of the grid-connected power of the wind turbine system 110. (See diagram below.) Figure 7 As shown, as the per-unit output power of the wind turbine system 110 increases, the self-damping coefficient D of the wind turbine system 110 also increases. a The energy storage system 120 requires frequent charging and discharging to mitigate wind power fluctuations. During high-speed power switching, the dynamic response of its converter control loop introduces negative damping due to phase delay. This reduces the self-damping coefficient D of the energy storage system 120. bThe mutual damping coefficient D decreases due to the system operating point offset. The power coupling between wind turbine system 110 and energy storage system 120 intensifies, significantly enhancing the negative damping effect generated by their interaction. c If the damping decreases, the total damping D′ of the wind-storage grid-connected system 100 will decrease, leading to a decline in the stability of the system.

[0074] To enhance the equivalent damping of the wind-storage grid-connected system and suppress oscillations, thereby improving the stability of the system, embodiments of this application propose... Figure 2 The wind-storage combined grid-connected system 200 is shown below. The equivalent damping calculation method of the wind-storage combined grid-connected system 200 is introduced below.

[0075] (2) The equivalent damping of the wind turbine system 210 (referred to as the first equivalent damping D) A The equivalent damping of the energy storage system 120 (referred to as the first equivalent damping D) and the energy storage system 120 B ).

[0076] like Figure 2 As shown, the wind-storage integrated grid-connected system 200 includes a first stability controller 211 and a second stability controller 221. The first stability controller 211 operates on the wind turbine system 210, and the second stability controller 221 operates on the energy storage system 220. Furthermore, as described in the above embodiments, the first stability controller 211 and the second stability controller 221 have the ability to perform preset processing on the input signal to obtain the output signal. This preset processing may include high-pass filtering with DC blocking, phase compensation, and gain amplification. Please refer to... Figure 3 and Figure 4 The diagrams show the structural schematics of the first stabilizing controller 211 and the second stabilizing controller 221, respectively.

[0077] It should be understood that, with the addition of the first stabilizer 211 and the second stabilizer 221, the first stabilizer 211 and the second stabilizer 221 can respectively control the DC voltage U of the wind turbine system 210. dc and the DC voltage U of the energy storage system 220 es The signal is then processed. Specifically, it first passes through a high-pass filter in the DC blocking stage. The high-pass filter acts as a filter, selectively allowing voltage signals of specific frequency bands to pass through, thus eliminating the influence of steady-state signals on the stabilizer. Next, the signal is processed through a phase compensation stage to compensate for the phase deviation between the controller's input and output signals. Further amplification and adjustment are performed through control gain, and finally, the signals are superimposed onto the outer loops of the DC voltage control for the wind turbine system's 210 grid-side converter and the energy storage system's 220 grid-side converter.

[0078] Thus, the equivalent damping D of the wind turbine system 210A (i.e., the first equivalent damping D) A The equivalent damping D of the wind turbine system 110 a The difference lies in the equivalent damping D of the wind turbine system 210. A It will also be affected by the first stability controller 211. Similarly, the equivalent damping D of the energy storage system 220... B (i.e., the second equivalent damping D) B The equivalent damping D of the energy storage system 120 b The difference lies in the equivalent damping D of the energy storage system 220. B It will also be affected by the second stabilizing controller 221. Specifically, such as Figure 8A As shown, S500 may include S801-S802: S801, Obtain the first transfer function G s1 Second transfer function G s2 The third transfer function G A Fourth transfer function G B and the fifth transfer function G C .

[0079] Among them, the above G A This reflects the control characteristics of the wind turbine system 210 under the action of the first stabilizing controller during its dynamic response process in cooperation with the energy storage system 220. B This reflects the control characteristics of the energy storage system 220 during its dynamic response process in cooperation with the wind turbine system 210 under the action of the second stabilizing controller. C This reflects the coupling relationship between the wind turbine system 210 and the energy storage system 220 during their collaborative operation. This G s1 This reflects the control characteristics of the first stabilizing controller 211 during the dynamic response process. (The last part, "G," appears to be a fragment and doesn't translate directly.) s2 It reflects the control characteristics of the second stabilizing controller 221 during the dynamic response process.

[0080] In this embodiment, based on the DC voltage dynamic characteristics of the wind turbine system 210 and the energy storage system 220, the wind turbine system 210 and the energy storage system 220 can be abstracted into a single-input single-output system, thus obtaining G. s1 G s2 G A G B and G C Specifically, such as Figure 8B As shown, S801 may include S801a-S801b.

[0081] S801a, Construct a damping torque model for a wind-storage integrated grid-connected system 200.

[0082] S801b: Using a modular analysis approach, the wind turbine system 210 and energy storage system 220 are abstracted into single-input single-output systems in the damping torque model, resulting in G. s1 G s2 G A G B and G C .

[0083] Please refer to Figure 9 This illustrates a schematic diagram of the damping torque model of a wind-storage integrated grid-connected system 200 provided in an embodiment of this application. Figure 9 As shown, in the damping torque model 900, the wind turbine system 210 and energy storage system 220 of the wind-storage grid-connected system 200 can be abstracted as a single-input single-output system (SISO), resulting in G. s1 G s2 G A G B and G C Among them, G A G B and G C The calculation method is the same as Figure 6 G shown 1 A G 1 B and G 1 C The details are as follows: ; ; .

[0084] Where C1 is the DC capacitor of the wind turbine system 210, C2 is the DC capacitor of the energy storage system 220, and s is the Laplace operator.

[0085] G a G represents the self-damping transfer function formed by the dynamic adjustment of the wind turbine system 210's power and voltage under the action of the first stabilizer controller, reflecting the ability of the wind turbine system 210's closed-loop control to suppress internal disturbances under the action of the first stabilizer controller. d G is the self-damping transfer function of the energy storage system 220 under the action of the second stability controller; c G represents the mutual damping transfer function of the wind turbine system 210 to the energy storage system 220, reflecting the dynamic impact of DC voltage fluctuations in the wind turbine system 210 on the energy storage system 220. b This is the mutual damping transfer function of the energy storage system 220 on the wind turbine system 210, reflecting the reaction of the energy storage system 220 on the wind turbine system 210.

[0086] PI A These are the PI parameters for the DC voltage loop of the wind turbine system 210. w1 U represents the steady-state current value of the turbine-side converter in the wind turbine system 210 under the action of the first stability controller. dcw1 PI is the steady-state value of the DC voltage of the wind turbine system 210 under the action of the first stabilizer controller. B For the PI parameters of the energy storage system 220, U esw2 This is the steady-state value of the power supply voltage of the energy storage system 220 under the action of the second stability controller.

[0087] The transfer function (i.e., the first transfer function G) of the first stability controller 211 in the wind-storage grid-connected system 200 s1 ) and the transfer function of the second stable controller 221 (i.e., the second transfer function G) s2 They are respectively: , .

[0088] Where T1, T2, and T3 are time constants, set based on the potential oscillation frequency of the wind-storage integrated grid-connected system 200. K1 is the stability control gain of the wind turbine system 210, and K2 is the stability control gain of the energy storage system 220. The aforementioned K1 affects G... s1 K2 affects G s2 .

[0089] The transfer function of the wind turbine system 210 under the action of the first stabilizing controller 211 is G. A +G s1 The transfer function of the energy storage system 220 under the action of the second stability controller 221 is G. B +G S2 The input-output transfer function of the interaction between the two systems is G. C .

[0090] S802, adopts G A +G s1 =D A + (K) A / s), for G A +G s1 Decompose to obtain D A ; Using G B +G s2 =D B + (K) B / s), for G B +G s2 Decompose to obtain D B ; Using G C=D C + (K) C / s), for G C Decompose to obtain D C .

[0091] According to the above formula, we can see that: , , .

[0092] The first equivalent damping D of the wind turbine system 210 under the action of the first stabilizing controller 211 can be obtained. A、 The second equivalent damping D of the energy storage system 220 under the action of the second stability controller 221 B and the coupling damping of the two systems D c They are respectively: , , .

[0093] In the above method, the value of the stability control gain K1 of the wind turbine system 210 affects the transfer function G of the first stability controller 211. s1 This, in turn, affects the equivalent damping of the wind turbine system 210; the value of the stability control gain K2 of the energy storage system 220 affects the transfer function G of the second stability controller 221. s2 This, in turn, affects the equivalent damping of the energy storage system 220.

[0094] This scheme establishes a system model of a wind-storage integrated grid-connected system with a stability controller, accurately quantifies the damping torque of each system, and thus reveals the variation law of the system's damping characteristics. Based on this, according to the damping calculation results, when the system exhibits an oscillation trend, the gain of the stability controller is tuned. By changing the gain of the stability controller, the unbalanced torque in the system is quickly offset, effectively suppressing low-frequency oscillations.

[0095] This application provides an oscillation suppression device for a wind-storage combined grid-connected system, comprising a wind turbine system and an energy storage system connected in parallel. The device also includes a first stability controller and a second stability controller. The input signal to the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilizer is the DC voltage U of the energy storage system. esThe first and second stabilizing controllers perform preset processing on the input signals to obtain the output signals. This preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. Specifically, the output signal of the first stabilizing controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, while the output signal of the second stabilizing controller acts on the outer loop of the DC voltage controlled by the energy storage converter of the energy storage system. Figure 10 This is a schematic diagram of the structure of an oscillation suppression device 1000 for a wind-storage combined grid-connected system provided in an embodiment of this application, as shown below. Figure 10 As shown, the oscillation suppression device 1000 of the wind-storage combined grid-connected system includes a setting module 1001.

[0096] The tuning module 1001 is used to tune the stability control gain K1 of the wind turbine system and the stability control gain K2 of the energy storage system until the total equivalent damping D of the wind-storage grid-connected system is greater than a preset value. The preset value is greater than zero. When D is less than zero, the wind-storage grid-connected system will oscillate and become unstable. D=D A +D B +D C K1 affects the first equivalent damping D A K2 affects the second equivalent damping D B .

[0097] Among them, D A D B and D C For the specific meaning and detailed explanation of , please refer to the relevant content in the method embodiments, which will not be repeated here.

[0098] In other embodiments, such as Figure 10 As shown, the oscillation suppression device 1000 of the wind-storage combined grid-connected system may further include: an acquisition module 1002 and a decomposition module 1003. The acquisition module 1002 can be used to acquire the first transfer function G. s1 Second transfer function G s2 The third transfer function G A Fourth transfer function G B and the fifth transfer function G C .

[0099] Among them, G s1 G s2 G A G B and G C For the specific meaning and detailed introduction of , please refer to the relevant content in the method embodiment, which will not be repeated here.

[0100] Decomposition module 1003 can be used to employ G A +G s1 =D A+ (K) A / s), for G A +G s1 The decomposition process yields D. A Using G B +G s2 =D B + (K) B / s), for G B +G s2 Decompose to obtain D B Using G C =D C + (K) C / s), for G C Decompose to obtain D C Where s is the Laplace operator, K A K B K C This is the synchronization coefficient. K1 affects D. A Specifically, K1 affects G s1 K2 affects D B Specifically, K2 affects G s2 .

[0101] In other embodiments, the acquisition module 1002 described above is specifically used to abstract the wind turbine system and energy storage system into a single-input single-output system based on the dynamic characteristics of the DC voltage of the wind turbine system and the energy storage system, and obtain G. s1 G s2 G A G B and G C .

[0102] In other embodiments, such as Figure 11 As shown, the acquisition module 1002 may include: a construction submodule 1002a and an analysis submodule 1002b.

[0103] Submodule 1002a is constructed to build a damping torque model for a wind-storage grid-connected system based on the dynamic characteristics of DC voltage of the wind turbine system and the energy storage system.

[0104] Analysis submodule 1002b is used to abstract the wind turbine system and energy storage system into a single-input single-output system in the damping torque model using a modular analysis approach, to obtain G. s1 G s2 G A G B and G C .

[0105] In other embodiments, the analysis submodule 1002b is specifically used to calculate G using the following formula. A GB and G C : , , .

[0106] Among them, C1, C2, s, G a G d G c G b PI A I w1 U dcw1 U esw2 and PI B For the specific meaning and detailed introduction of , please refer to the relevant content in the method embodiment, which will not be repeated here.

[0107] In other embodiments, the analysis submodule 1002b is specifically used to calculate G using the following formula. s1 and G s2 : , .

[0108] Wherein, T1, T2, and T3 are all time constants, and are set based on the potential oscillation frequency of the wind-storage combined grid-connected system. The oscillation suppression device for a wind-storage combined grid-connected system provided in this application embodiment can execute the method shown in the above method embodiment. Its implementation principle and beneficial effects can be found in the relevant descriptions in the method embodiment, and will not be repeated here. Furthermore, each module in the above-mentioned oscillation suppression device for the wind-storage combined grid-connected system can be implemented entirely or partially through software, hardware, or a combination thereof. Each of the above modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0109] In other embodiments, a computer device is provided. This computer device may be the wind-storage grid-connected system described in the above method embodiments, used to execute the method steps performed by the control device or the oscillation suppression device of the wind-storage grid-connected system in the above method flow. The internal structure of the computer device may be as follows: Figure 12 As shown, it includes a processor, memory, input / output interfaces (I / O), and communication interfaces.

[0110] The processor, memory, and input / output interface are connected via a system bus, and the communication interface is also connected to the system bus via the input / output interface. The processor of this computer device provides computing and control capabilities. The memory of this computer device includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of this computer device is used to store data. The input / output interface of this computer device is used for exchanging information between the processor and external devices. The communication interface of this computer device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements an oscillation suppression method for a wind-storage integrated grid-connected system.

[0111] Those skilled in the art will understand that Figure 12 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0112] In some embodiments, a computer device includes a memory, a processor, and a communication interface. The communication interface is used to interact with other devices to transmit and receive data. For example, in this embodiment, the communication interface can specifically be used to transmit damping information of each part of a wind-storage grid-connected system, as well as the total damping information of the system. The memory is used to store computer program code, which includes computer instructions. These computer instructions run in the computer device to implement the method shown in the above-described method embodiments. For example, the memory may include high-speed random access memory (RAM), and may also include non-volatile memory (NVM), such as at least one disk storage device, or a USB flash drive, portable hard drive, read-only memory, disk, or optical disk, etc.

[0113] The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The processor can also be other general-purpose processors. A general-purpose processor can be a microprocessor or any conventional processor.

[0114] Memory, communication interfaces, and processor communication connections. For example, memory and communication interfaces can connect to the processor via the system bus and communicate with each other. The system bus can be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, an Industry Standard Architecture (ISA) bus, etc. The system bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0115] Alternatively, the memory can be either standalone or integrated with the processor. When the memory is set up independently, it is connected to the processor via the system bus.

[0116] This application also provides a chip for executing instructions, which is used to implement the technical solution of the oscillation suppression method for a wind-storage combined grid-connected system described in the above embodiments.

[0117] This application also provides a computer-readable storage medium storing computer instructions. When these computer instructions are executed by a processor, they are used to implement the technical solution of the oscillation suppression method for a wind-storage combined grid-connected system described in the above embodiments. Specifically, when the computer instructions are executed by a processor, the control device or the oscillation suppression device of the wind-storage combined grid-connected system can execute the technical solution of the oscillation suppression method for a wind-storage combined grid-connected system described in the above embodiments.

[0118] This application also provides a computer program product, which includes a computer program stored in a computer-readable storage medium. At least one processor can read the computer program from the computer-readable storage medium. When the at least one processor executes the computer program, it can implement the technical solution of the oscillation suppression method of the wind-storage combined grid-connected system described in the above embodiments.

[0119] The aforementioned computer-readable storage media can be implemented using any type of volatile or non-volatile storage device or a combination thereof. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), etc.

[0120] Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). Computer-readable storage media may be any available medium accessible to general-purpose or special-purpose computers.

[0121] An exemplary computer-readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the computer-readable storage medium can also be a component of the processor. The processor and the computer-readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor and the computer-readable storage medium can exist as discrete components in an electronic control unit or main control device; this application does not limit this.

[0122] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0123] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0124] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit composed of the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0125] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods of the various embodiments of this application.

[0126] It should be understood that the steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0127] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0128] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for oscillation suppression in a wind-storage grid-connected system, wherein the wind-storage grid-connected system comprises a wind turbine system and an energy storage system connected in parallel, characterized in that, The wind-storage integrated grid-connected system also includes a first stability controller and a second stability controller; the input signal of the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilization controller is the DC voltage U of the energy storage system. es The first and second stabilization controllers perform preset processing on the input signals to obtain output signals. This preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilization controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, and the output signal of the second stabilization controller acts on the outer loop of the DC voltage of the energy storage converter of the energy storage system. The method includes: Adjust the stability control gain K1 of the wind turbine system and the stability control gain K2 of the energy storage system until the total equivalent damping D of the wind-storage grid-connected system is greater than the preset value. Wherein, the preset value is greater than zero; where D is less than zero, the wind-storage combined grid-connected system oscillates and becomes unstable; D=D A +D B +D C The K1 affects the first equivalent damping D A The K2 affects the second equivalent damping D B The D A The self-damping coefficient of the wind turbine system under the action of the first stability controller reflects the ability of the wind turbine system's closed-loop control to suppress voltage fluctuations under the action of the first stability controller; the D B The self-damping coefficient of the energy storage system under the action of the second stabilizing controller reflects the ability of the energy storage system's closed-loop control to suppress voltage fluctuations under the action of the second stabilizing controller; coupling damping D C The mutual damping coefficient between the wind turbine system and the energy storage system is given.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the first transfer function G s1 The second transfer function G s2 The third transfer function G A Fourth transfer function G B and the fifth transfer function G C ; wherein, the G s1 The G reflects the control characteristics of the first stabilizing controller during the dynamic response process. s2 Reflecting the control characteristics of the second stabilizing controller during the dynamic response process; the G A The control characteristics of the wind turbine system under the action of the first stabilizing controller during the dynamic response process in cooperation with the energy storage system are reflected in the G. B The control characteristics of the energy storage system under the action of the second stability controller during the dynamic response process in cooperation with the wind turbine system are reflected in the G. C This reflects the coupling relationship between the wind turbine system and the energy storage system during their collaborative operation. Using G A +G s1 =D A + (K) A / s), for the G A +G s1 Decompose to obtain D A ; Using G B +G s2 =D B + (K) B / s), for the G B +G s2 Decompose to obtain D B ; Using G C =D C + (K) C / s), for the G C Decompose to obtain D C ; Wherein, s is the Laplace operator; K A The K B The K C Synchronization coefficient; The K1 affects the D A Specifically, K1 affects G s1 K2 affects the D B Specifically, K2 affects G s2 .

3. The method according to claim 2, characterized in that, The first transfer function G is obtained s1 The second transfer function G s2 The third transfer function G A Fourth transfer function G B and the fifth transfer function G C ,include: Based on the DC voltage dynamic characteristics of the wind turbine system and the energy storage system, the wind turbine system and the energy storage system are abstracted as a single-input single-output system, resulting in G. s1 The G s2 The G A The G B and the G C .

4. The method according to claim 3, characterized in that, Based on the DC voltage dynamic characteristics of the wind turbine system and the energy storage system, the wind turbine system and the energy storage system are abstracted into a single-input single-output system, resulting in G. s1 The G s2 The G A The G B and the G C ,include: Based on the DC voltage dynamic characteristics of the wind turbine system and the energy storage system, a damping torque model of the wind-storage grid-connected system is constructed. Using a modular analysis approach, the wind turbine system and the energy storage system are abstracted into a single-input single-output system in the damping torque model, resulting in the G... s1 The G s2 The G A The G B and the G C .

5. The method according to claim 4, characterized in that, ， ， ； Wherein, C1 is the DC capacitor of the wind turbine system, C2 is the DC capacitor of the energy storage system; s is the Laplace operator; The G a G represents the self-damping transfer function formed by the dynamic adjustment of the wind turbine system's power and voltage under the action of the first stabilizing controller, reflecting the ability of the wind turbine system's closed-loop control to suppress internal disturbances under the action of the first stabilizing controller; d G is the self-damping transfer function of the energy storage system under the action of the second stability controller; c The G is the mutual damping transfer function of the wind turbine system to the energy storage system, reflecting the dynamic impact of DC voltage fluctuations in the wind turbine system on the energy storage system; b The mutual damping transfer function of the energy storage system on the wind turbine system reflects the reaction of the energy storage system on the wind turbine system; The PI A The I represents the PI parameters of the DC voltage loop of the wind turbine system. w1 U is the steady-state current value of the turbine-side converter of the wind turbine system under the action of the first stability controller. dcw1 The PI is the steady-state value of the DC voltage of the wind turbine system under the action of the first stabilizing controller. B For the PI parameters of the energy storage system, the U esw2 The steady-state value of the power supply voltage of the energy storage system under the action of the second stabilization controller.

6. The method according to any one of claims 2-5, characterized in that, The K1 affects the G s1 Specifically: ; The K2 affects the G s2 Specifically: ; Wherein, T1, T2 and T3 are all time constants, and T1, T2 and T3 are set based on the potential oscillation frequency of the wind-storage integrated grid-connected system.

7. An oscillation suppression device for a wind-storage combined grid-connected system, the wind-storage combined grid-connected system comprising a wind turbine system and an energy storage system connected in parallel, characterized in that, The wind-storage integrated grid-connected system also includes a first stability controller and a second stability controller; the input signal of the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilization controller is the DC voltage U of the energy storage system. es The first and second stabilization controllers perform preset processing on the input signals to obtain output signals. This preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilization controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, and the output signal of the second stabilization controller acts on the outer loop of the DC voltage controlled by the energy storage converter of the energy storage system. The device includes: The tuning module is used to tune the stability control gain K1 of the wind turbine system and the stability control gain K2 of the energy storage system until the total equivalent damping D of the wind-storage grid-connected system is greater than a preset value; wherein, the preset value is greater than zero; if D is less than zero, the wind-storage grid-connected system oscillates and becomes unstable; D=D A +D B +D C The K1 affects the first equivalent damping D A The K2 affects the second equivalent damping D B The D A The self-damping coefficient of the wind turbine system under the action of the first stability controller reflects the ability of the wind turbine system's closed-loop control to suppress voltage fluctuations under the action of the first stability controller; the D B The self-damping coefficient of the energy storage system under the action of the second stabilizing controller reflects the ability of the energy storage system's closed-loop control to suppress voltage fluctuations under the action of the second stabilizing controller; coupling damping D C The mutual damping coefficient between the wind turbine system and the energy storage system is given.

8. A control device for a wind-storage combined grid-connected system, the wind-storage combined grid-connected system comprising a wind turbine system and an energy storage system connected in parallel, characterized in that, The wind-storage integrated grid-connected system also includes a first stability controller and a second stability controller; the input signal of the first stability controller is the DC voltage U of the wind turbine system. dc The input signal of the second stabilization controller is the DC voltage U of the energy storage system. es The first and second stabilization controllers perform preset processing on the input signals to obtain output signals. The preset processing includes high-pass filtering with DC blocking, phase compensation, and gain amplification. The output signal of the first stabilization controller acts on the outer loop of the DC voltage controlled by the grid-side converter of the wind turbine system, and the output signal of the second stabilization controller acts on the outer loop of the DC voltage of the energy storage converter of the energy storage system. The control device includes a memory and at least one processor, and also includes related devices / equipment for wind and energy storage grid connection. The memory is communicatively connected to the processor; the memory is used to store computer program code, the computer program code including computer instructions; when the processor executes the computer instructions, it causes the control device to perform the method as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, are used to implement the method as described in any one of claims 1-6.

10. A computer program product, characterized in that, When the computer program product is run on a computer / executed by the computer's processor, it implements the method as described in any one of claims 1-6.

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