Multi-scale energy storage system control method and system

Abstract

The invention belongs to the technical field of energy storage systems, and provides a multi-scale energy storage system control method and system, and the technical scheme is that a centralized access mode is adopted, an energy storage device is connected to a wind power grid-connected bus, damping control is adopted, a power oscillation damper is additionally arranged, and damping is increased by controlling the output of a DFIG; mode damping, filtering and phase compensation are improved through a POD control structure installed on the machine side; low-frequency oscillation is suppressed through energy storage, positive damping is provided for frequency oscillation of the system, when low-frequency oscillation occurs in the frequency of the system, the energy storage dynamically adjusts the active output according to the frequency change of the system, the control modes mainly include droop control, inertia control and nonlinear control, power compensation and peak load shifting are achieved, the energy storage utilization rate is high, and the energy storage efficiency is high. Damping control is adopted for a multi-scale energy storage system and a new energy system, a power oscillation damper is additionally arranged, and the small disturbance stability of a high-permeability regional power grid is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage systems, and in particular relates to a multi-scale energy storage system control method and system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] There are two ways to connect wind turbines to the grid: distributed and centralized. Distributed access means that each wind turbine is equipped with a storage device. The required storage capacity is small and the compensation is flexible, but it requires multiple control devices and is complex to install. Centralized access means that a set of storage devices is installed at the access point. The required storage capacity is large, but only one control device is needed, which is easier to control centrally. Moreover, the output of each wind power is not exactly the same, and there is partial complementarity. The utilization rate of energy storage in centralized access is higher. At present, the control efficiency of wind turbines connected to the grid is low, the delay of receiving signals is large, which is easy to cause asynchrony and inconvenient to adjust active power. Summary of the invention

[0004] In order to solve at least one technical problem existing in the above-mentioned background technology, the present invention provides a multi-scale energy storage system control method and system, which adopts a centralized access mode, connects the energy storage device to the busbar of the wind power grid, realizes power compensation and peak shaving, and makes the energy storage utilization rate high.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A first aspect of the present invention provides a multi-scale energy storage system control method, comprising the following steps:

[0007] Determine the control system scheme of the multi-scale energy storage system; the control system scheme of the multi-scale energy storage system is: adopt a centralized access method, connect the energy storage system to the busbar of the wind power grid, and install a power oscillation damper on the doubly-fed asynchronous wind turbine generator;

[0008] Based on the determined multi-scale energy storage system control structure scheme, the active power of the energy storage system is dynamically adjusted by utilizing the frequency change of the energy storage system; specifically, it includes:

[0009] During the off-peak load phase, damping is increased by controlling the output of the doubly-fed asynchronous wind turbine generator, and the frequency information of the coupling node port of the wind-storage system is used as the input of the power oscillation damper instead of the angular frequency of the traditional synchronous generator to modulate the output active power of the energy storage system.

[0010] Furthermore, a power oscillation damper is installed in the active control loop of the machine-side converter, including four modules, namely, an amplifier gain unit, a DC isolation link, a leading module and a lagging module. The frequency information of the coupling node port of the wind-storage system passes through the amplifier gain unit, the DC isolation link, the leading module and the lagging module in sequence. The signal is amplified by the amplifier gain unit, the mode damping is enhanced by the gain unit, the steady-state component is filtered out by the DC isolation link, and the phase compensation is performed through the leading module and the lagging module before output.

[0011] Furthermore, the output formula of the power oscillation damper is:

[0012]

[0013] Among them, K POD , T h , T d1 , T d2 , T d3 and T d4 is the control parameter, T D is the sensor time constant, s is the Laplace operator, G POD is the transfer function of POD, f PCC It is the frequency information of the coupling node port of the wind-storage system.

[0014] Furthermore, in the control system scheme of the multi-scale energy storage system, a dual PWM controller is used to control the bidirectional flow of energy, the output active power and reactive power are decoupled and controlled by RSC, and the input power factor is controlled by GSC. When the doubly fed asynchronous wind generator operates in a subsynchronous state, energy flows from the grid side to the rotor side of the doubly fed asynchronous wind generator; when the doubly fed asynchronous wind generator operates in a supersynchronous state, energy flows from the rotor side of the doubly fed asynchronous wind generator to the grid side.

[0015] Furthermore, droop control, inertia control and nonlinear control are used to dynamically adjust the output active power of the energy storage system. For the low-frequency oscillation of the power grid, the inertia level of the power system is enhanced by adjusting the inertia control. The droop control mode enhances the positive damping of the power system. When the unbalanced power in the energy storage system is greater than the set value, the nonlinear control mode is used to make the energy storage output at maximum power.

[0016] Furthermore, the active output current formula of the energy storage system is:

[0017] I d * =(K p +sK d )(ω0-ω)=(K p +sK d )Δω,

[0018] In the formula, K p ,K d is the gain of the PD controller in the speed loop, ω0 is the synchronous angular frequency, ω is the measured grid angular frequency, and Δω is the difference between the measured grid angular frequency and the synchronous angular frequency.

[0019] A second aspect of the present invention provides a multi-scale energy storage system control system, comprising:

[0020] A system installation scheme determination module is used to determine the control system scheme of the multi-scale energy storage system; wherein the control system scheme of the multi-scale energy storage system is: using a centralized access method, connecting the energy storage system to the busbar of the wind power grid, and installing a power oscillation damper on the double-fed asynchronous wind turbine generator;

[0021] The energy storage system control scheme is used to dynamically adjust the active power of the energy storage system by utilizing the frequency change of the energy storage system based on the determined multi-scale energy storage system control structure scheme; specifically includes:

[0022] During the off-peak load phase, damping is increased by controlling the output of the doubly-fed asynchronous wind turbine generator, and the frequency information of the coupling node port of the wind-storage system is used as the input of the power oscillation damper instead of the angular frequency of the traditional synchronous generator to modulate the output active power of the energy storage system.

[0023] A third aspect of the present invention provides a computer-readable storage medium.

[0024] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps in the multi-scale energy storage system control method as described above.

[0025] A fourth aspect of the present invention provides a computer device.

[0026] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in the multi-scale energy storage system control method as described above are implemented.

[0027] A fifth aspect of the present invention provides a program product, which is a computer program product, including a computer program, and when the computer program is executed by a processor, the steps in the multi-scale energy storage system control method as described above are implemented.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts a centralized access method to connect the energy storage device to the busbar of the wind power grid, realize power compensation and peak load shifting, and achieve high energy storage utilization rate.

[0030] 2. The present invention adopts the method of installing a power oscillation damper on the DFIG in the non-peak load stage to achieve a function similar to that of the SG-PSS, and to increase the damping by controlling the DFIG output. The rotor speed of the SG is closely related to the LFO mode, and the frequency information f of the coupling node port of the wind storage system is used. PCC Replace the traditional SG ω tn As the input of POD, it improves the synchronization accuracy of the speed signal received by the wide area measurement system and can efficiently modulate the output active power.

[0031] 3. The present invention adopts damping control for multi-scale energy storage systems and new energy systems, and installs power oscillation dampers. From the perspective of local system-level control, an equivalent model is formed according to the local quantity measurement of the power grid; on the basis of the equivalent model, a stability evaluation is performed to obtain a stability index; based on the stability index, the specific control quantity at the equipment level is calculated; based on the specific control quantity, the power oscillation damper is smoothly adjusted to enhance the small disturbance stability of the power grid in the high penetration area.

[0032] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 A schematic diagram of the wind energy storage system model structure provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of the control structure of a DFIG with an additional POD provided in an embodiment of the present invention;

[0036] Figure 3 A structural diagram of a POD controller installed in a generator-side converter provided in an embodiment of the present invention;

[0037] Figure 4 Schematic diagram of the control strategy for ESS to suppress low-frequency oscillation of the power grid in a wind-storage system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Explanation of terms

[0042] DFIG: Doubly fed Induction Generator (DFIG) is the most widely used wind turbine generator, which consists of a wound-type asynchronous generator with a stator winding directly connected to a fixed-frequency three-phase power grid and a bidirectional back-to-back IGBT voltage source converter installed on the rotor winding;

[0043] LFO: Low Frequency Oscillator (LFO), which is used to modulate other parameters in synthesizers and effects by generating a slowly oscillating signal;

[0044] RSC: Rotor Side Converter;

[0045] GSC: Grid Side Converter;

[0046] POD: power oscillation damper (POD);

[0047] ESS: Energy Storage System (ESS) is a system that can store electrical energy and supply power, with functions such as smooth transition, peak shaving and valley filling, frequency and voltage regulation, etc.

[0048] SG: synchronous generator (SG);

[0049] Figure 1 The schematic diagram of the wind storage system model is shown in Figure 2. Figure 1 The wind farm and energy storage system are connected to the grid. After the wind farm and energy storage system are connected to the grid, the wind and energy storage system are interconnected through the energy manager (EMS). W and energy storage system P ESS Joint decision, expressed as:

[0050] P PCC =P W +PESS ,

[0051] Among them, P ESS The positive and negative values ​​represent the charging and discharging status of the energy storage. A positive value represents energy storage discharging, and a negative value represents energy storage charging.

[0052] Embodiment 1

[0053] This embodiment provides a multi-scale energy storage system control method, comprising the following steps:

[0054] Step 1: Determine the control system solution for the multi-scale energy storage system;

[0055] In this embodiment, a centralized access method is adopted to connect the energy storage device to the busbar of the wind power grid, and a power oscillation damper is installed on the DFIG. Damping control is adopted to increase the damping by controlling the DFIG output.

[0056] Specifically, damping control is adopted for multi-scale energy storage systems and new energy systems, and power oscillation dampers (PODs) are installed to enhance the small disturbance stability of power grids in high penetration areas.

[0057] During the off-peak load period, part of the SG is replaced by wind power, and the original SG stability control strategy may not be available. For this reason, POD can be installed on the DFIG to achieve functions similar to SG-PSS, and increase damping by controlling the DFIG output.

[0058] The rotor speed of the SG is closely related to the LFO mode, with the frequency information f of the wind-storage system coupling node port PCC Replace the traditional SG rotor speed ω in As the input of POD, it reduces the synchronization problem of the wide area measurement system receiving the speed signal and modulates the output active power.

[0059] POD controller gain factor K POD It directly affects the damping effect of the controller. When selecting, the output compensation power capacity constraint should be considered so that it does not exceed the total output of the wind power system. At the same time, the impact of the controller output power on the terminal voltage of the synchronous machine should be considered so that its fluctuation value does not exceed the limit. Therefore, under these two constraints, the control coefficient with the most obvious damping effect can be selected through frequency domain analysis.

[0060] According to the control object, POD can be divided into active control, reactive control and active / reactive mixed control.

[0061] POD can achieve different functions and obtain different oscillation suppression effects when installed in different positions. It can suppress the oscillation amplitude when installed in the rotor-side converter (RSC).

[0062] Installed in the grid-side converter (GSC), it can speed up the oscillation convergence. s The sensitivity is higher than Q s , U dc or Q g Stronger.

[0063] In this embodiment, the POD is installed in the active power control loop of the RSC.

[0064] Among them, the POD control structure installed on the machine side is as follows Figure 3 As shown in the figure, it consists of four modules. The first module is the POD amplifier gain unit, the second module is the DC isolation link, and the third and fourth modules are the lead and lag modules respectively. Among them, the gain unit is used to enhance the mode damping; the DC isolation link is used for filtering to filter out the steady-state component. When the signal changes to a steady state, the POD output is zero; the lead and lag module is used for phase compensation to compensate for the phase shift of the frequency measurement and filtering links in the low-frequency band without the need for external power grid information.

[0065] The corresponding output power of the power oscillation damper is shown as follows:

[0066]

[0067] Among them, K POD , T h , T d1 , T d2 , T d3 and T d4 is the control parameter, T D is the sensor time constant, s is the Laplace operator, G POD is the transfer function of POD.

[0068] The POD control structure installed on the machine side can improve mode damping, filtering and phase compensation.

[0069] Step 2: Based on the determined multi-scale energy storage system control structure scheme, the active power of the energy storage system is dynamically adjusted by utilizing the frequency change of the energy storage system;

[0070] Damping control is adopted for multi-scale energy storage systems and new energy systems, and power oscillation dampers (PODs) are installed to enhance the small disturbance stability of power grids in high penetration areas. During the off-peak load phase, some SGs are replaced by wind power, and the original SG stability control strategy may not be available. For this reason, PODs can be installed on DFIGs to achieve functions similar to SG-PSS, and damping can be increased by controlling the DFIG output.

[0071] like Figure 2 As shown, the dual PWM controller is used to realize the bidirectional flow of energy. When the DFIG works in the subsynchronous state, the energy flows from the grid side to the DFIG rotor side; when the DFIG works in the supersynchronous state, the energy flows from the DFIG rotor side to the grid side.

[0072] The RSC is used to realize the decoupling control of the output active power and reactive power, and the GSC is used to realize the control of the input power factor and the DC voltage regulation.

[0073] In this embodiment, droop control, inertia control and nonlinear control are used to dynamically adjust the output active power of the energy storage system. For low-frequency oscillations of the power grid, inertia control is adjusted to enhance the inertia level of the power system. The droop control mode enhances the positive damping of the power system. When the unbalanced power in the energy storage system is greater than the set value, the nonlinear control mode is used to enable the energy storage to output at maximum power.

[0074] Specifically include:

[0075] By suppressing low-frequency oscillations through energy storage, positive damping is provided for the frequency oscillation of the system. When the system frequency undergoes low-frequency oscillations, the energy storage dynamically adjusts its active output according to the frequency changes of the system. The control methods mainly include droop control, inertia control and nonlinear control.

[0076] 1. ESS control structure: Energy storage suppresses low-frequency oscillations by providing positive damping for the system's frequency oscillations. When the system frequency undergoes low-frequency oscillations, its active output is dynamically adjusted according to the frequency changes of the energy storage system. Its control methods mainly include droop control, inertia control (damping control) and nonlinear control (maximum power output in local time periods).

[0077] Figure 4 It is an application scenario for the grid-connected wind energy storage system, which mainly includes synchronous generators, doubly-fed wind turbines, ESS and infinite power grid. e is the electromagnetic power of the synchronous machine; P W is the active power output of the doubly-fed wind turbine; P ESS is the active power output by ESS; I d ,I q are the d-axis and q-axis output currents in the dq coordinate system respectively; They are the command values ​​of the d-axis and q-axis output currents respectively.

[0078] Depend on Figure 4 The active output current of the ESS output

[0079]

[0080] In the formula, K p ,K dis the gain of the PD controller in the speed loop. For the low-frequency oscillation of the power grid, the existing control strategies mainly include inertia control and droop control; ω0 is the synchronous angular frequency, and ω is the measured grid angular frequency. Assume that ESS only provides active support and does not consider the impact of reactive power on the system. Set the reactive current set value I q * Always zero.

[0081] The expression of electromagnetic power increment of synchronous machine under electromechanical time scale is:

[0082] ΔP e =K g Δδ-K ESS ΔI d ,

[0083] In the formula, K g K is the power grid synchronization coefficient, which represents the synchronous and stable operation capability of the power system itself; ESS It is the control parameter of energy storage, which characterizes the influence of ESS on the dynamic characteristics of the power grid under the control strategy. Therefore, when the power grid oscillates, the electromagnetic power of the synchronous machine will change.

[0084] If the active power injected by ESS into the grid is taken into account, the damping coefficient and inertia coefficient of the power system are:

[0085]

[0086] Where D and H are the inherent damping and inertia coefficient of the system.

[0087] From the above formula, it can be obtained that the action mode of the P controller is equivalent to droop control, and the D controller is equivalent to inertia control. Therefore, droop control suppresses the angular frequency difference Δω by enhancing the positive damping of the power system. Δω is the difference between the measured grid angular frequency and the synchronous angular frequency. Inertia control mainly suppresses the oscillation coefficient by enhancing the inertia level of the power system. is the derivative of the measured grid angular frequency per unit time; the above two types of control can directly or indirectly affect S ω , thereby suppressing the low-frequency oscillation of the power grid.

[0088] Step 5: When the unbalanced power in the system is large, the ESS releases energy in a short time, and the energy storage is output at maximum power in the nonlinear control mode.

[0089] Considering the ESS control strategy with limited energy storage converter capacity, when the unbalanced power in the system is large, the ESS needs to release (absorb) enough energy P in a short time. max, which may exceed the inverter capacity setting. At this time, even if the control parameters of inertia control and droop control are adjusted, it is difficult to suppress low-frequency oscillations. It is necessary to use nonlinear control mode to make the energy storage output at maximum power.

[0090] When the power grid is in steady state operation, the mechanical power P m Equal to electromagnetic power P e When a load disturbance ΔP occurs L When the system has excess energy, the power absorbed by the ESS device is ΔP ESS , so the synchronous generator rotor motion equation is:

[0091] When the ESS device is in the maximum power modulation state, ΔP ESS =P max ,have to:

[0092]

[0093] At the initial moment of the oscillation, the ESS has not yet been put into operation, ΔP ESS =0, the maximum speed change rate is:

[0094]

[0095] Taking inertia control as an example, the output of ESS under inertia control does not exceed the capacity limit P max ,Right now:

[0096]

[0097] So the D controller gain K d We can get:

[0098]

[0099]

[0100] The rotor motion equation under ESS inertia control mode is obtained:

[0101]

[0102] The speed change rate of the synchronous machine under inertia control is obtained as follows:

[0103]

[0104] The difference is:

[0105]

[0106] Therefore, under maximum power modulation, ESS The suppression effect of inertia control is better than that of inertia control.

[0107] Through the above scheme, damping control is adopted for multi-scale energy storage systems and new energy systems, and power oscillation dampers are installed to enhance the small disturbance stability of the power grid in high penetration areas.

[0108] Embodiment 2

[0109] This embodiment provides a multi-scale energy storage system control system, which adopts a multi-scale energy storage system control method described in Embodiment 1, including:

[0110] A system installation scheme determination module is used to determine the control system scheme of the multi-scale energy storage system; wherein the control system scheme of the multi-scale energy storage system is: using a centralized access method, connecting the energy storage system to the busbar of the wind power grid, and installing a power oscillation damper on the double-fed asynchronous wind turbine generator;

[0111] The energy storage system control scheme is used to dynamically adjust the active power of the energy storage system by utilizing the frequency change of the energy storage system based on the determined multi-scale energy storage system control structure scheme; specifically includes:

[0112] During the off-peak load phase, damping is increased by controlling the output of the doubly-fed asynchronous wind turbine generator, and the frequency information of the coupling node port of the wind-storage system is used as the input of the power oscillation damper instead of the angular frequency of the traditional synchronous generator to modulate the output active power of the energy storage system.

[0113] The specific implementation process of each module in Example 2 is consistent with that in Example 1 and will not be repeated here.

[0114] Embodiment 3

[0115] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the multi-scale energy storage system control method as described above are implemented.

[0116] Embodiment 4

[0117] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in the multi-scale energy storage system control method described above are implemented.

[0118] Embodiment 5

[0119] This embodiment provides a program product, which is a computer program product, including a computer program, characterized in that when the computer program is executed by a processor, the steps in the multi-scale energy storage system control method as described above are implemented.

[0120] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0121] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0122] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0124] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-scale energy storage system control method, characterized in that: The steps include: Determine the control system scheme of the multi-scale energy storage system; the control system scheme of the multi-scale energy storage system is: adopt a centralized access method, connect the energy storage system to the busbar of the wind power grid, and install a power oscillation damper on the doubly-fed asynchronous wind turbine generator; Based on the determined multi-scale energy storage system control structure scheme, the active power of the energy storage system is dynamically adjusted by utilizing the frequency change of the energy storage system; specifically, it includes: During the off-peak load phase, damping is increased by controlling the output of the doubly-fed asynchronous wind turbine generator, and the frequency information of the coupling node port of the wind-storage system is used as the input of the power oscillation damper instead of the angular frequency of the traditional synchronous generator to modulate the output active power of the energy storage system.

2. A multi-scale energy storage system control method according to claim 1, characterized in that: The power oscillation damper is installed in the active control loop of the machine-side converter, which includes four modules, namely, the amplifier gain unit, the DC isolation link, the leading module and the lagging module. The frequency information of the coupling node port of the wind-storage system passes through the amplifier gain unit, the DC isolation link, the leading module and the lagging module in sequence. The signal is amplified by the amplifier gain unit, the mode damping is improved by the gain unit, the steady-state component is filtered out by the DC isolation link, and the phase compensation is performed through the leading module and the lagging module before output.

3. A multi-scale energy storage system control method according to claim 1, characterized in that: The output formula of the power oscillation damper is: Among them, K POD , T h , T d1 , T d2 , T d3 and T d4 is the control parameter, T D is the sensor time constant, s is the Laplace operator, G POD is the transfer function of POD, f PCC It is the frequency information of the coupling node port of the wind-storage system.

4. A multi-scale energy storage system control method according to claim 1, characterized in that: In the control system scheme of the multi-scale energy storage system, a dual PWM controller is used to control the bidirectional flow of energy, the output active power and reactive power are decoupled and controlled by RSC, and the input power factor is controlled by GSC. When the doubly fed asynchronous wind generator operates in a subsynchronous state, energy flows from the grid side to the rotor side of the doubly fed asynchronous wind generator; when the doubly fed asynchronous wind generator operates in a supersynchronous state, energy flows from the rotor side of the doubly fed asynchronous wind generator to the grid side.

5. A multi-scale energy storage system control method according to claim 1, characterized in that: Droop control, inertia control and nonlinear control are used to dynamically adjust the output active power of the energy storage system. In response to the low-frequency oscillation of the power grid, the inertia level of the power system is enhanced by adjusting the inertia control. The droop control mode enhances the positive damping of the power system. When the unbalanced power in the energy storage system is greater than the set value, the nonlinear control mode is used to make the energy storage output at maximum power.

6. A multi-scale energy storage system control method according to claim 1, characterized in that: The active output current formula of the energy storage system is: I d * =(K p +sK d )(ω0-ω)=(K p +sK d )See, In the formula, K p ,K d is the gain of the PD controller in the speed loop, ω0 is the synchronous angular frequency, ω is the measured grid angular frequency, and Δω is the difference between the measured grid angular frequency and the synchronous angular frequency.

7. A multi-scale energy storage system control system, using a multi-scale energy storage system control method as claimed in any one of claims 1 to 6, characterized in that: include: A system installation scheme determination module is used to determine the control system scheme of the multi-scale energy storage system; wherein the control system scheme of the multi-scale energy storage system is: using a centralized access method, connecting the energy storage system to the busbar of the wind power grid, and installing a power oscillation damper on the double-fed asynchronous wind turbine generator; The energy storage system control scheme is used to dynamically adjust the active power of the energy storage system by utilizing the frequency change of the energy storage system based on the determined multi-scale energy storage system control structure scheme; specifically includes: During the off-peak load phase, damping is increased by controlling the output of the doubly-fed asynchronous wind turbine generator, and the frequency information of the coupling node port of the wind-storage system is used as the input of the power oscillation damper instead of the angular frequency of the traditional synchronous generator to modulate the output active power of the energy storage system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a multi-scale energy storage system control method as described in any one of claims 1 to 6 are implemented.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the multi-scale energy storage system control method as described in any one of claims 1-6 are implemented.

10. A program product, the program product being a computer program product, comprising a computer program, characterized in that: When the computer program is executed by a processor, the steps in a multi-scale energy storage system control method as described in any one of claims 1 to 6 are implemented.

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