Transient state support power coordination control method and system of network construction type optical storage system

Abstract

The invention belongs to the technical field of VSG network construction active support, and particularly discloses a transient support power coordination control method and system for a network construction type optical storage system, and the method comprises the steps: building an equivalent mathematical model of the network construction type optical storage system, and obtaining key control parameters of a virtual synchronous generator control link of the optical storage system based on the equivalent mathematical model; constructing an internal energy flow characteristic analysis model of the network construction type optical storage system based on key control parameters of a control link of the virtual synchronous generator, and further obtaining a core defect of passive participation of energy storage in transient response; and based on the core defects, designing an energy storage driving control strategy based on VSG transient response power decomposition to control an energy storage subsystem to charge and discharge, and completing transient support power coordination control of the network construction type optical storage system. The problems that in the prior art, due to the fact that energy storage passively participates in frequency modulation, response timeliness and accuracy are insufficient, and due to the fact that VSG transient control complexity is high, large-scale engineering application adaptability is poor are solved.

Description

Technical Field

[0001] This invention belongs to the field of intelligent transportation and low-carbon technology, specifically relating to a transient support power coordination control method and system for a grid-type photovoltaic energy storage system. Background Technology

[0002] Currently, renewable energy accounts for over 30% of installed capacity. Traditional grid-connected photovoltaic-storage systems, lacking active support capabilities, exhibit "negative damping" characteristics, making it difficult to meet the stability requirements of a high proportion of renewable energy grid connection. Grid-connected photovoltaic-storage technologies with active frequency / voltage support capabilities have become the core solution. However, existing grid-connected systems have significant drawbacks: First, energy storage passively participates in primary frequency regulation only through DC bus voltage, unable to actively output power based on grid frequency drops / rises, resulting in a disconnect from the transient demands of the virtual synchronous generator (VSG), leading to lag in response and poor support during frequency disturbances. Second, VSG transient energy relies excessively on DC bus capacitance, and energy storage is not deeply coupled with VSG control, resulting in limited transient support duration and potentially forcing photovoltaics to deviate from maximum power point tracking (MPPT) mode, reducing energy utilization. Third, some improved solutions require additional sensors to acquire transient signals, increasing hardware costs and control complexity, making them unsuitable for large-scale applications. Therefore, optimizing control strategies is urgently needed to overcome these bottlenecks.

[0003] The existing technology mainly has the following problems: 1. Delayed energy storage response. When a grid-connected photovoltaic-storage system encounters a frequency step change at the grid connection point (e.g., 50Hz → 49.8Hz) or a deep voltage drop, the primary frequency regulation needs to complete the active power response within 0.1s to suppress frequency and voltage degradation. However, existing strategies are not adapted to the dynamic characteristics of VSG (moment of inertia J, damping D) and the energy storage charging and discharging rate. For example, the exponential adaptive strategy is prone to parameter spikes, resulting in a 0.05-0.1s delay in energy storage response. This makes it impossible to fill the power gap in time, greatly prolonging the frequency recovery time and significantly weakening the system's transient support effect.

[0004] 2. Insufficient energy storage responsiveness. Existing strategies (such as JD coordinated adaptive) do not establish a direct correlation model between energy storage output and VSG active power regulation. They only reduce the energy storage regulation frequency through parameter optimization, which cannot accurately match the active power demand under fault conditions. This can easily lead to a 10%-20% power overshoot of the rated value, resulting in overcharging and discharging of the energy storage. This not only shortens the energy storage life by 15%-20%, but also causes severe fluctuations in DC voltage of ±8%-±12% of the rated value, disrupting DC side stability and even triggering the current limiting protection of the photovoltaic inverter, reducing energy utilization by 5%-8%.

[0005] 3. Poor ease of engineering application. Existing strategies require additional sensors or independent measurement components to acquire transient signals in order to achieve transient active power-frequency regulation and multi-condition adaptation. This not only increases hardware costs by 30%-50%, but also easily leads to a decrease in control accuracy due to synchronization deviations of signals from multiple modules. At the same time, transient control modules are mostly designed independently and cannot be directly integrated into the original VSG control loop. A separate parameter debugging system needs to be built, which extends the debugging cycle by more than 60%, seriously restricting the convenience and economy of large-scale deployment of distributed photovoltaic energy storage. Summary of the Invention

[0006] The purpose of this invention is to address the problems of insufficient response timeliness and accuracy caused by the passive participation of energy storage in frequency regulation in existing technologies, as well as the poor adaptability to large-scale engineering applications due to the high complexity of VSG transient control. This invention proposes a transient support power coordination control method and system for grid-type photovoltaic-energy storage systems.

[0007] The technical solution of the present invention is as follows: Firstly, a method for coordinated control of transient support power in a grid-type photovoltaic-storage system, comprising the following steps: An equivalent mathematical model of a grid-type photovoltaic-storage system is established, and key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system are obtained based on the equivalent mathematical model. Based on the key control parameters of the virtual synchronous generator control link, an internal energy flow characteristic analysis model of the grid-type photovoltaic-storage system is constructed, thereby revealing the core shortcomings of energy storage passively participating in transient response. Based on the core deficiencies, an energy storage drive control strategy based on VSG transient response power decomposition is designed to control the energy storage subsystem for charging and discharging, thereby completing the transient support power coordination control of the grid-type photovoltaic energy storage system.

[0008] As a preferred option, the power relationship of the equivalent mathematical model of the grid-type photovoltaic-storage system is as follows:

[0009] in, Indicates photovoltaic power. Indicates energy storage capacity. This indicates the power loss of a grid-type photovoltaic energy storage system. This indicates the output power of the inverter control subsystem. Indicates grid-connected power. This indicates the local load power.

[0010] Preferably, the key control parameters include the driving torque; the driving torque is obtained by dividing the transient response power of the virtual synchronous generator by the rated angular velocity.

[0011] Preferably, the energy storage drive control strategy based on VSG transient response power decomposition is as follows: The driving torque is decomposed into an inertial torque component characterizing the dynamic response of the frequency change rate and a damping torque component characterizing the steady-state regulation of the frequency deviation. The inertial torque component and the damping torque component are added together after being adjusted for their respective gains, and then filtered to obtain the inertial damping reference current. The inertia damping reference current is input to the energy storage DC-DC control loop to obtain the final reference current command for driving the charging and discharging of the energy storage subsystem of the grid-type photovoltaic energy storage system. This allows the energy storage subsystem to be controlled to charge and discharge, thus completing the transient support power coordination control for the grid-type photovoltaic energy storage system.

[0012] Preferably, the inertial torque component and the damping torque component are added together after corresponding gain adjustments, and then filtered to obtain the inertial damping reference current. This process specifically includes the following steps: The inertial torque component is adjusted via a first gain coefficient to obtain a first adjustment signal; The damping torque component is adjusted via a second gain coefficient to obtain a second adjustment signal; The first adjustment signal is added to the second adjustment signal to obtain the third signal; The third signal is input to a low-pass filter for smoothing, and then adjusted by the third gain coefficient to obtain the inertia damping reference current.

[0013] Preferably, after the inertia damping reference current is input to the energy storage DC-DC control loop, the control of the energy storage DC-DC control loop is as follows:

[0014] in, Indicates duty cycle, This represents the proportional gain of the PI controller. This indicates the reference value for the output current of the energy storage battery. This represents the inertia damping reference current. This indicates the output current of the energy storage battery. This represents the integral coefficient of the PI controller. Indicates time, Indicates the rated duty cycle. This indicates the DC-side port voltage of the DC-DC converter. This indicates the voltage at the battery-side port of the DC-DC converter.

[0015] As a preferred option, the formula for calculating the output current of the energy storage battery is:

[0016] in, This indicates the output voltage of the energy storage battery. Represents the equivalent circuit resistance. Indicates the equivalent circuit inductance. This represents a differential operator.

[0017] The beneficial effects of this invention are: 1. This invention achieves improved frequency stability performance through active response frequency modulation of energy storage: by decomposing the transient response power of the VSG into inertial torque. t H Directly driving energy storage to quickly participate in frequency regulation: In scenarios where the grid frequency drops to 49.8Hz within 3 seconds, t H It can respond instantly, reduce the frequency drop by up to 15.1%, effectively curb the frequency deterioration in the early stage of a fault, and increase the active power recovery speed on the AC side by up to 21.87%.

[0018] 2. This invention promotes a dual improvement in transient support and energy utilization through the synergy of VSG and energy storage: the damping torque is decomposed from the transient response power of the VSG. t D By deeply coupling VSG control with energy storage DC-DC conversion, energy storage can continuously replenish transient energy for the VSG, preventing photovoltaic power generation from frequently deviating from the MPPT mode due to capacitor charging and discharging. This increases photovoltaic power generation utilization by 8%-10% during the grid's 3-second frequency recovery phase. t D By specifically adjusting the frequency deviation, the system frequency deviation was reduced by up to 38.3%, achieving a dual improvement in system transient support and energy utilization.

[0019] 3. This invention significantly improves the ease of engineering application by simplifying the control structure: relying on the inherent signal of VSG (driving torque) t SVG This achieves transient response power decomposition without requiring additional sensors or independent measurement circuits; and the decomposed power is obtained... t H , t D It can be directly integrated into the existing VSG control loop without the need to build a separate control module, reducing debugging difficulty, and is compatible with multiple operating conditions such as voltage dips (e.g., under voltage dips). t H / t D It can still respond accurately, providing convenient conditions for the large-scale engineering deployment of distributed optical storage.

[0020] Secondly, a transient support power coordination control system for a grid-type photovoltaic-storage system includes: The first module is used to establish an equivalent mathematical model of the grid-type photovoltaic-storage system, and to obtain the key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system based on the equivalent mathematical model. The second module is used to construct an internal energy flow characteristic analysis model of a grid-type photovoltaic-storage system based on the key control parameters of the virtual synchronous generator control link, thereby obtaining the core shortcomings of energy storage passively participating in transient response. The third module is used to design an energy storage drive control strategy based on VSG transient response power decomposition to control the energy storage subsystem for charging and discharging, based on the core deficiency, and to complete the transient support power coordination control of the grid-type photovoltaic energy storage system.

[0021] Thirdly, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method as described in the first aspect.

[0022] Fourthly, a non-transitory computer-readable storage medium is provided that stores computer instructions for causing a computer to perform the method as described in the first aspect. Attached Figure Description

[0023] Figure 1 The diagram shows a flowchart of a transient support power coordination control method for a grid-type photovoltaic energy storage system.

[0024] Figure 2 The diagram shows the topology of a grid-type integrated photovoltaic and energy storage system.

[0025] Figure 3 The diagram shown is a control block diagram of a grid-type converter with added energy storage.

[0026] Figure 4 The diagram shows the energy flow of a grid-type integrated photovoltaic and energy storage system.

[0027] Figure 5 The diagram shows the equivalent circuit of the energy storage battery and the DC-DC converter.

[0028] Figure 6 The diagram shows the energy storage drive control block diagram based on VSG transient response power decomposition.

[0029] Figure 7 The figure shows the response characteristics of virtual synchronization control to grid frequency drops.

[0030] Figure 8 The figure shows the response characteristics of virtual synchronous control to grid voltage dips. Detailed Implementation

[0031] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the drawings are merely exemplary and are intended to illustrate the principles and spirit of the invention, and are not intended to limit the scope of the invention.

[0032] Example 1: like Figure 1 As shown, a method for coordinated control of transient support power in a grid-type photovoltaic-storage system includes the following steps: S1. Establish an equivalent mathematical model of the grid-type photovoltaic-storage system, and obtain the key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system based on the equivalent mathematical model; A complete equivalent mathematical model of a grid-type photovoltaic-storage system is established, and the topology of the integrated grid-type photovoltaic-storage unit and the control architecture of the grid-type converter are analyzed in depth. This provides a model foundation for accurately characterizing the energy flow path of the photovoltaic system with DC-side energy storage and the improved grid-type control structure. Furthermore, the inertia coefficient, damping coefficient, and driving torque are directly obtained through model analysis. t SVG Inertia torque t H Damping torque t D and angular velocity oh Key control parameters such as 0 lay the parameter foundation for subsequent defect identification and control improvement analysis.

[0033] S2. Based on the key control parameters of the virtual synchronous generator control link, an internal energy flow characteristic analysis model of the grid-type photovoltaic-storage system is constructed to obtain the core shortcomings of energy storage passively participating in transient response. The control parameters (inertia coefficient, damping coefficient, driving torque) calculated using the mathematical model in step S1 t SVG An internal energy flow characteristic analysis model of a grid-type photovoltaic-storage integrated system (grid-type photovoltaic-storage system) was constructed. Combined with the energy storage response speed requirements when the VSG grid actively supports the system, the core deficiency of this model—passive participation of energy storage in transient response—was identified. To address this deficiency, this invention adds an energy storage driving mechanism based on the transient response power of the VSG, upgrading energy storage from "passive following" to "active support," effectively improving the system's transient response speed and support capability.

[0034] S3. Based on the core deficiencies, an energy storage drive control strategy based on VSG transient response power decomposition is designed to control the energy storage subsystem to charge and discharge, and to complete the transient support power coordination control of the grid-type photovoltaic energy storage system. After analyzing the insufficient control parameters in step S3 above, based on the analysis conclusions and proposed improvement directions, this invention relies on a primary frequency regulation mechanism to instantaneously generate transient response power to support grid frequency stability. Specifically, dividing the transient response power of the VSG obtained in step S1 by the rated angular velocity ω0 yields the driving torque τ of the VSG. SVG Furthermore, through dynamic component separation, τ SVG Innovatively decomposed into inertial torque τ H and damping torque τ D .

[0035] in, t H Primarily corresponds to the dynamic response of the rate of change of frequency, used to provide rapid inertial support; t D This primarily corresponds to steady-state adjustment of frequency deviation, used to provide continuous inertial support. t H and t D The signals pass through the gain coefficients respectively K H and gain coefficient K D After amplitude adjustment, the two values ​​are added together and then input into a gain coefficient of... K HD The inertia time constant is T The low-pass filter is used for smoothing to obtain the inertia-damped reference current of the input energy storage control loop. i HD .Will i HD By inputting the energy storage DC-DC control loop, the final reference current command used to drive the charging and discharging of the energy storage subsystem can be generated.

[0036] In this embodiment, an equivalent mathematical model of the grid-type optical energy storage system is constructed, specifically as follows: To enhance the transient support capability of grid-type photovoltaic-storage systems under disturbance scenarios, it is necessary to construct an equivalent mathematical model. This model provides a foundation for accurately characterizing the energy flow path of the photovoltaic system with DC-side additional energy storage and the improved grid-type control structure. Furthermore, it allows for the direct acquisition of inertia coefficients, damping coefficients, and driving torque through model analysis. t SVG Inertia torque t H Damping torque t D and angular velocity oh Key control parameters such as 0 lay the parameter foundation for subsequent defect identification and control improvement analysis.

[0037] The integrated photovoltaic and energy storage system consists of a photovoltaic power generation subsystem, an energy storage subsystem, and an inverter control subsystem, and its grid connection structure is as follows: Figure 2 and Figure 3 As shown. In grid-connected mode, the photovoltaic power source and energy storage subsystem work together to supply local loads and transmit power to the grid, with the DC-side capacitor... C dc With energy balanced on both sides, the power relationship of the grid-connected system is as follows:

[0038] in, P pv For photovoltaic power, P BESS For energy storage power, P loss This refers to system power loss. P e For the inverter control system output power, P g For grid-connected power, P load This represents the local load power. The absolute value of the power to be mitigated, i.e., the power that the energy storage subsystem needs to provide, is |Δ. P |=| P e - P pv + P loss |

[0039] In this embodiment, the analysis of the internal energy flow characteristics of the grid-type photovoltaic energy storage system is specifically as follows: Based on the equivalent model of a grid-type photovoltaic energy storage system, its internal energy flow can be re-characterized as follows: Figure 4 As shown, the photovoltaic panels convert sunlight into heat energy, which is then fed into the DC side of the converter via a DC-DC converter. The stored energy can also be fed into the DC side of the converter via a DC-DC converter, and finally fed into the power grid through the converter.

[0040] During grid disturbances, the grid-side inverter in a photovoltaic-storage system is the core port for interaction with the grid, and its transient response energy characteristics are dominated by VSG control. When energy storage is connected via DC / DC, the transient energy of the grid-side inverter no longer relies solely on the DC capacitor, effectively reducing its dependence.

[0041] To simplify calculations, the energy storage battery and its DC-DC converter are equivalent to, for example: Figure 4 The circuit topology is shown. Under the current loop control framework, the duty cycle... D c As a control variable, it can be used to control the DC-DC converter's DC-DC port voltage. u dcThe dynamic regulation is mathematically represented as follows:

[0042] In the formula, i BESSref This is a reference value for the output current of the energy storage battery. i BESS Output current to the energy storage battery; D c0 This is the rated duty cycle; k p , k i These are the proportional and integral coefficients of the PI controller, respectively. This indicates the voltage at the battery-side port of the DC-DC converter. Battery output current. i BESS and voltage u BESS They can be represented as:

[0043] in, R BESS , L BESS These are the equivalent circuit resistance and inductance, respectively. U BESS0 This refers to the rated voltage of the energy storage battery. C BESS This is the equivalent capacitance of the energy storage battery; This represents the differential operator. The charging and discharging power of the energy storage battery system during operation. P BESS This can be further expressed as:

[0044] When using the grid-type converter control described above, a dynamic correlation can be established between the DC voltage and the grid frequency. According to the technical requirements of the energy storage converter in the energy storage subsystem, the active power response time constraint should be:

[0045] However, when actively supporting VSG grid construction, energy storage cannot directly respond to disturbances and can only passively participate through DC-side voltage. It cannot promptly generate power to suppress the continued decline of grid frequency or absorb power to suppress the continued rise of grid frequency when grid frequency drops or rises. Its response speed and accuracy are significantly insufficient.

[0046] This invention establishes a correlation mechanism between energy storage and the transient response power of a VSG, transforming the inertia support and damping adjustment requirements of the VSG into precise control signals for energy storage. This matches the energy storage output with the system requirements during frequency disturbances, satisfying the requirement for rapid frequency stabilization in grid-type systems. This correlation mechanism will be elaborated below.

[0047] In this embodiment, the energy storage drive control strategy based on VSG transient response power decomposition is specifically as follows: Depend on Figure 3 As can be seen from the grid-type converter control structure, when the grid frequency experiences a frequency dip, the VSG control, relying on the primary frequency regulation mechanism, can instantaneously generate transient response power to support frequency stability. Considering the limitation in the above analysis that energy storage can only passively participate in the transient response through DC voltage, this invention decomposes the VSG transient response power into inertial response components and damping response components, thus enabling rapid and precise driving of the energy storage subsystem.

[0048] To address the frequency support requirements of grid-type integrated photovoltaic and energy storage systems, this invention innovatively proposes an energy storage drive control strategy based on VSG transient response power decomposition, the control block diagram of which is shown below. Figure 5 As shown.

[0049] Divide the transient response power of the VSG by the rated angular velocity. oh 0, the driving torque of the VSG can be obtained. t SVG Furthermore, through dynamic component separation, t SVG It can be decomposed into inertia torque. t H and damping torque t D .in t H The dynamic response corresponding to the rate of change of frequency. t D The steady-state adjustment corresponding to the frequency deviation together constitutes the core control signal for energy storage drive.

[0050] Inertia Torque t H and damping torque t D The signals pass through the gain coefficients respectively K H and gain coefficient K D The input gain coefficient after adding the two is: K HD The inertia time constant is T A low-pass filter can be used to obtain the inertia-damped reference current input to the energy storage control loop by the virtual synchronization control. i HDIt can be represented as:

[0051] By adjusting K H , K D and K HD The size can directly determine the energy storage pair t H and t D The degree of response. The control of the energy storage DC-DC converter can be rewritten as: .

[0052] In this embodiment, an application analysis of the power coordination control method proposed in this invention shows that the driving torque of the VSG... t SVG The parameters can be directly obtained from the equivalent mathematical model established in step S1, without the need for additional sensors or measurement components, thus significantly improving the ease of engineering implementation and cost-effectiveness of the solution. Simultaneously, the control parameters obtained in step S1 can be used to control the disturbance conditions. t SVG , t H and t D The signal trajectory was extrapolated and simulated, and the results verified the rationality and effectiveness of the transient response decomposition strategy proposed in this invention. The decomposition results highly match the power output characteristics required by energy storage under disturbances identified in step S2, accurately matching the rapid and continuous power output demands of energy storage during transient processes. The application analysis of the power coordination control method is as follows: Thus, this invention constructs an equivalent mathematical model of a grid-type photovoltaic-storage system, analyzes its internal energy flow characteristics, and develops a power coordination control method to improve the transient support capability of a grid-type photovoltaic-storage system by deconstructing the power-driven energy storage of the VSG transient response under disturbance.

[0053] Whether it's the torque generated by the power loop in the VSG t SVG It was obtained by splitting it up. t H and t D All of these originate from the inherent transient signals of network control and are naturally integrated into it. Figure 6 The VSG control loop shown does not require additional sensors or measurement components. This feature fully leverages the "signal nativeness" advantage of virtual synchronous network control, simplifies the system hardware structure and control complexity, and provides convenience for engineering applications.

[0054] The transient response characteristics of a grid-connected photovoltaic system under frequency drop conditions are as follows: Figure 7 As shown.

[0055] At 3 seconds, the power grid frequency suddenly dropped to 49.8 Hz and recovered to the rated level in 3.3 seconds. As can be seen from the response curve, t H It can respond quickly to sudden frequency changes (following the rate of change of frequency d). f / d t This effectively suppresses the frequency drop amplitude; t D The damping adjustment is then applied to address the subsequent continuous frequency deviation, accelerating the frequency recovery to a steady-state value. The two work together to achieve full-process control of frequency "rapid support-smooth recovery".

[0056] To verify the generality of this strategy, Figure 8 The transient response under voltage sag conditions is given: t SVG It can also be decomposed into t H and t D Furthermore, the two types of torque components achieve dynamic response and damping adjustment according to voltage change characteristics, which further confirms the accuracy of the power decomposition logic and the working condition adaptability of the control strategy proposed in this invention.

[0057] In existing grid-type photovoltaic-storage systems, the energy storage subsystem passively participates in primary frequency regulation only through DC bus voltage, and cannot actively output or absorb power to suppress frequency degradation in response to grid frequency changes (such as frequency steps of 0.2-0.5Hz). The power coordination control method establishes a correlation mechanism between energy storage and the transient response power of the VSG, transforming the inertia support and damping adjustment requirements of the VSG into precise control signals for energy storage. This matches the energy storage output with system demand during frequency disturbances, meeting the requirements of grid-type systems for rapid frequency stabilization.

[0058] In existing systems, the transient energy of the VSG mainly relies on the DC bus capacitor for supply, and energy storage is not deeply coupled with VSG control. This not only results in limited transient support time (insufficient capacitor energy storage, only able to maintain operation for 0.05-0.2s), but also easily forces the photovoltaic system to frequently deviate from the MPPT mode due to capacitor energy release / replenishment demands, reducing energy utilization. The power coordination control method utilizes the damping torque derived from the power decomposition of the VSG transient response under fault conditions. t D and inertia torque t H The drive energy storage subsystem does not require additional sensors or independent measurement components to obtain transient signals, making it suitable for large-scale engineering applications of distributed photovoltaic energy storage.

[0059] This invention provides a transient support power coordination control method for a grid-connected photovoltaic-storage system, aiming to overcome the shortcomings of existing technologies such as passive participation of energy storage in frequency regulation, inaccurate response, and high complexity of VSG transient control. It deeply integrates energy storage into VSG control, improves the transient response performance of the system, simplifies the control structure, and ensures the stability and reliability of a high-proportion photovoltaic-storage grid-connected system under disturbances.

[0060] Example 2: Based on Embodiment 1, this embodiment of the invention provides a transient support power coordination control system for a grid-type photovoltaic-storage system, which can be used to implement the transient support power coordination control method for the grid-type photovoltaic-storage system as described in the foregoing embodiments. The system includes: The first module is used to establish an equivalent mathematical model of the grid-type photovoltaic-storage system, and to obtain the key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system based on the equivalent mathematical model. The second module is used to construct an internal energy flow characteristic analysis model of a grid-type photovoltaic-storage system based on the key control parameters of the virtual synchronous generator control link, thereby obtaining the core shortcomings of energy storage passively participating in transient response. The third module is used to design an energy storage drive control strategy based on VSG transient response power decomposition to control the energy storage subsystem for charging and discharging, based on the core deficiency, and to complete the transient support power coordination control of the grid-type photovoltaic energy storage system.

[0061] According to embodiments of the present invention, the present invention also provides an electronic device, a readable storage medium, and a computer program product.

[0062] In an exemplary embodiment, the electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the transient support power coordination control method for the grid-type optical energy storage system as described in Embodiment 1 above.

[0063] In an exemplary embodiment, the readable storage medium may be a non-transient computer-readable storage medium storing computer instructions for causing a computer to execute the transient support power coordination control method for the network-type optical storage system according to Embodiment 1 above.

[0064] In an exemplary embodiment, the computer program product includes a computer program that, when executed by a processor, implements the transient support power coordination control method for a grid-type optical energy storage system according to Embodiment 1 above.

[0065] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0066] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0067] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0068] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with embodiments of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0069] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0070] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A method for coordinated control of transient support power in a grid-type photovoltaic-storage system, characterized in that, Includes the following steps: An equivalent mathematical model of a grid-type photovoltaic-storage system is established, and key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system are obtained based on the equivalent mathematical model. Based on the key control parameters of the virtual synchronous generator control link, an internal energy flow characteristic analysis model of the grid-type photovoltaic-storage system is constructed, thereby revealing the core shortcomings of energy storage passively participating in transient response. Based on the core deficiencies, an energy storage drive control strategy based on VSG transient response power decomposition is designed to control the energy storage subsystem for charging and discharging, thereby completing the transient support power coordination control of the grid-type photovoltaic energy storage system.

2. The transient support power coordination control method for a grid-type photovoltaic energy storage system according to claim 1, characterized in that, The power relationship of the equivalent mathematical model of the grid-type photovoltaic energy storage system is as follows: in, Indicates photovoltaic power. Indicates energy storage capacity. This indicates the power loss of a grid-type photovoltaic energy storage system. This indicates the output power of the inverter control subsystem. Indicates grid-connected power. This indicates the local load power.

3. The transient support power coordination control method for a grid-type photovoltaic-storage system according to claim 1, characterized in that, Key control parameters include drive torque; drive torque is obtained by dividing the transient response power of the virtual synchronous generator by the rated angular velocity.

4. The transient support power coordination control method for a grid-type photovoltaic energy storage system according to claim 3, characterized in that, The energy storage drive control strategy based on VSG transient response power decomposition is as follows: The driving torque is decomposed into an inertial torque component characterizing the dynamic response of the frequency change rate and a damping torque component characterizing the steady-state regulation of the frequency deviation. The inertial torque component and the damping torque component are added together after being adjusted for their respective gains, and then filtered to obtain the inertial damping reference current. The inertia damping reference current is input to the energy storage DC-DC control loop to obtain the final reference current command for driving the charging and discharging of the energy storage subsystem of the grid-type photovoltaic energy storage system. This allows the energy storage subsystem to be controlled to charge and discharge, thus completing the transient support power coordination control for the grid-type photovoltaic energy storage system.

5. The transient support power coordination control method for a grid-type photovoltaic energy storage system according to claim 4, characterized in that, The inertial torque component and the damping torque component are added together after being adjusted for their respective gains, and then filtered to obtain the inertial damping reference current. The specific steps include: The inertial torque component is adjusted via a first gain coefficient to obtain a first adjustment signal; The damping torque component is adjusted via a second gain coefficient to obtain a second adjustment signal; The first adjustment signal is added to the second adjustment signal to obtain the third signal; The third signal is input to a low-pass filter for smoothing, and then adjusted by the third gain coefficient to obtain the inertia damping reference current.

6. The transient support power coordination control method for a grid-type photovoltaic energy storage system according to claim 4, characterized in that, After the inertia damping reference current is input to the energy storage DC-DC control loop, the control of the energy storage DC-DC control loop is as follows: in, Indicates duty cycle, This represents the proportional gain of the PI controller. This indicates the reference value for the output current of the energy storage battery. This represents the inertia damping reference current. This indicates the output current of the energy storage battery. This represents the integral coefficient of the PI controller. Indicates time, Indicates the rated duty cycle. This indicates the DC-side port voltage of the DC-DC converter. This indicates the voltage at the battery-side port of the DC-DC converter.

7. The transient support power coordination control method for a grid-type photovoltaic-storage system according to claim 6, characterized in that, The formula for calculating the output current of an energy storage battery is: in, This indicates the output voltage of the energy storage battery. Represents the equivalent circuit resistance. Indicates the equivalent circuit inductance. This represents a differential operator.

8. A transient support power coordination control system for a grid-type photovoltaic-storage system, characterized in that, include: The first module is used to establish an equivalent mathematical model of the grid-type photovoltaic-storage system, and to obtain the key control parameters of the virtual synchronous generator control link of the photovoltaic-storage system based on the equivalent mathematical model. The second module is used to construct an internal energy flow characteristic analysis model of a grid-type photovoltaic-storage system based on the key control parameters of the virtual synchronous generator control link, thereby obtaining the core shortcomings of energy storage passively participating in transient response. The third module is used to design an energy storage drive control strategy based on VSG transient response power decomposition to control the energy storage subsystem for charging and discharging, based on the core deficiency, and to complete the transient support power coordination control of the grid-type photovoltaic energy storage system.

9. An electronic device, characterized in that, include: At least one processor; And a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the method according to any one of claims 1-7.

10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method according to any one of claims 1-7.

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