Phase-locking method, electronic equipment, and storage medium for energy storage system

Abstract

The present application relates to the technical field of grid-connected energy storage systems, and in particular to a phase-locking method, electronic device, and storage medium for energy storage systems. The phase-locking method for energy storage systems includes: collecting grid voltage, generating a set of orthogonal signals based on the grid voltage; obtaining the phase error between the energy storage system and the grid based on the orthogonal signals and the phase reference angle in the PI controller; judging the state of the energy storage system, and if the energy storage system is in an off-grid output state, executing a slow phase-locking strategy based on the phase error, otherwise executing a fast phase-locking strategy based on the phase error. By adopting the method of the present application, it is possible to achieve no significant distortion in the output voltage when the energy storage system switches from an off-grid state to a grid-connected state, thereby ensuring the safe and reliable operation of the load electrical appliances, and to make a timely and rapid response to the dynamic changes in the grid voltage when the energy storage system is connected to the grid.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage system grid connection, and in particular to a phase locking method, electronic equipment and storage medium for an energy storage system. Background Art

[0002] In energy storage systems, commonly used phase-locking schemes are categorized as hardware and software. The hardware solution uses a phase comparator, voltage-controlled oscillator, and loop filter to compare and lock the grid phase with the system's internal phase. The software solution processes the grid voltage to generate a quadrature signal. These two signals are then processed to determine the current grid phase. The resulting grid phase is then subtracted from the energy storage system's internal operating phase. A PI controller is then used to track and lock the internal operating phase to the grid phase, ultimately achieving complete locking of the energy storage system and grid information.

[0003] Among the aforementioned phase-locking schemes, hardware phase-locking is implemented through hardware functional circuits. This automatically identifies the specific phase of the grid and enables the internal phase to track the grid phase. However, this requires the addition of a phase comparator, voltage-controlled oscillator, and loop filter, significantly increasing the cost, size, and weight of the energy storage system. Furthermore, this heavy reliance on hardware introduces a greater potential for failure, impacting the stability of the energy storage system.

[0004] Conventional software phase-locking solutions are implemented through software logic. While they can handle most application scenarios, they still have some performance issues in certain special scenarios. For example, when pursuing faster phase-locking speeds, if the orthogonal signals in the phase-locking phase from off-grid to grid-connected state have some input reference angular frequency errors, the generated orthogonal signals will be significantly distorted, causing the output voltage of the energy storage system to be significantly distorted for several cycles. If the energy storage system is in an output-loaded state at this time, it may affect the normal operation of the load electrical devices or even cause permanent damage to the load electrical devices. Reducing the phase-locking speed will prevent the energy storage system from responding quickly to grid fluctuations, affecting system stability. Summary of the Invention

[0005] The embodiments of the present invention aim to provide a phase locking method, electronic device, and storage medium for an energy storage system, so as to solve some performance problems existing in software phase locking solutions in certain special application scenarios in the prior art.

[0006] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a phase-locking method for an energy storage system, comprising:

[0008] collecting a grid voltage and generating a set of orthogonal signals based on the grid voltage;

[0009] Obtaining a phase error between the energy storage system and the power grid based on the quadrature signal and a phase reference angle in a PI controller;

[0010] Determine the state of the energy storage system. If the energy storage system is in an off-grid output state, execute a slow phase-locking strategy based on the phase error; otherwise, execute a fast phase-locking strategy based on the phase error.

[0011] Among them, the fast phase-locking strategy is to execute the PI control algorithm once in each phase-locking program operation cycle, and the slow phase-locking strategy is to execute the PI control algorithm once in N phase-locking program operation cycles. The PI control algorithm is used to obtain a PI output signal based on the phase error to update the phase reference angle, and N is an integer greater than 1.

[0012] Optionally, the operating frequency of the PI control algorithm in the slow phase-locked strategy is the same as the rated frequency of the power grid.

[0013] Optionally, the N phase-locked program execution cycles include one PI controller execution cycle and (N-1) non-PI controller execution cycles, and the executing a slow phase-locked strategy based on the phase error includes:

[0014] During the PI controller execution period, a proportional-integral operation is performed based on the phase error to obtain the PI output signal, and during the non-PI controller execution period, the PI output signal is set to 0.

[0015] Optionally, the PI output signal is an angular frequency correction value or a phase angle correction value. When the PI output signal is a phase angle correction value, the calculation formula of the phase reference angle is:

[0016]

[0017] in, is the current phase reference angle, is the phase reference angle of the last phase-locked program operation cycle, is the phase angle correction, is the grid phase angle change step, is the current grid phase angle, The grid phase angle of the last phase-locked program operation cycle;

[0018] When the PI output signal is an angular frequency correction value, the calculation formula of the phase reference angle is:

[0019]

[0020] in, is the grid reference angular frequency, is the rated frequency of the grid, is the angular frequency correction amount.

[0021] Optionally, before determining the state of the energy storage system, the step further includes:

[0022] obtaining a grid voltage amplitude and a grid frequency based on the grid voltage;

[0023] Based on the grid voltage amplitude and the grid frequency, it is determined whether the current grid state meets the preset grid connection conditions of the energy storage system. If so, the step of determining the state of the energy storage system is entered; if not, the phase-locking procedure is exited.

[0024] Optionally, collecting the grid voltage and generating a set of orthogonal signals based on the grid voltage includes:

[0025] When the grid voltage is a single-phase grid voltage, the grid voltage is input into an orthogonal generator to generate a set of orthogonal signals;

[0026] When the grid voltage is a three-phase grid voltage, the grid voltage is subjected to Clarke transformation to generate a set of orthogonal signals.

[0027] Optionally, obtaining a phase error between the energy storage system and the grid based on the orthogonal signal and a phase reference angle in a PI controller includes:

[0028] Calculating a grid phase angle based on the quadrature signal using an inverse tangent formula;

[0029] The difference between the grid phase angle and the phase reference angle is used as the phase error between the energy storage system and the grid.

[0030] Optionally, when the grid voltage is a three-phase grid voltage, obtaining the phase error between the energy storage system and the grid based on the orthogonal signal and the phase reference angle in the PI controller includes:

[0031] A Park transform is performed based on the orthogonal signal and the phase reference angle to obtain a d component signal and a q component signal, and the q component signal is used as the phase error between the energy storage system and the power grid.

[0032] In a second aspect, an embodiment of the present application provides an electronic device comprising: at least one processor and a memory communicatively connected to the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute any of the methods described above.

[0033] In a third aspect, an embodiment of the present application provides a computer storage medium, which stores instructions or programs. When the instructions or programs are executed by at least one processor, the at least one processor executes any one of the methods described above.

[0034] The beneficial effects of the embodiments of the present invention are as follows: Different from the prior art, the embodiments of the present invention provide a phase-locking method for an energy storage system, which first collects the grid voltage, generates a set of orthogonal signals based on the grid voltage, and obtains the phase error between the energy storage system and the grid based on the orthogonal signals and the phase reference angle in the PI controller; then determines the state of the energy storage system. If the energy storage system is in an off-grid output state, a slow phase-locking strategy is executed based on the phase error, otherwise a fast phase-locking strategy is executed based on the phase error; wherein the fast phase-locking strategy is to execute the PI control algorithm once in each phase-locking program operation cycle, and the slow phase-locking strategy is to execute the PI control algorithm once in N phase-locking program operation cycles. In the method of the present application, the phase-locked loop of the inverter continuously identifies the current working state of the energy storage system during phase locking, and selects different phase-locking frequencies for adaptive phase locking according to the current working state of the energy storage system. This method can effectively take into account various scenarios of the use of the energy storage system, and can not only achieve no significant output voltage distortion when the energy storage system switches from an off-grid state to a grid-connected state, thereby ensuring the safe and reliable operation of the load electrical appliances, but also make timely and rapid responses to dynamic changes in the grid voltage when connected to the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0036] Figure 1 This is a flow chart of a phase-locking method for an energy storage system provided by an embodiment of the present invention;

[0037] Figure 2 is a detailed flow chart of a phase-locking method for an energy storage system provided by an embodiment of the present invention;

[0038] Figure 3 This is a detailed flow chart of a phase-locking method for a three-phase energy storage system provided by an embodiment of the present invention;

[0039] Figure 4 Schematic diagram comparing the grid voltage and output voltage when the energy storage system provided by an embodiment of the present invention switches from an off-grid loaded state to a grid-connected state using a conventional software phase-locking method and using the phase-locking method of the present application;

[0040] Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0042] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0044] Please refer to Figure 1 , Figure 1 This is a flow chart of a phase-locking method for an energy storage system provided by an embodiment of the present invention. Figure 1 As shown, the method includes:

[0045] Step S101 : collecting grid voltage and generating a set of orthogonal signals based on the grid voltage.

[0046] In one embodiment, the energy storage system is a single-phase energy storage system, the grid connected thereto is also a single-phase grid, and the grid voltage is a single-phase grid voltage. The specific implementation of step S101 is: inputting the grid voltage into an orthogonal generator to generate a set of orthogonal signals. Preferably, the orthogonal generator is a second-order generalized integrator. The second-order generalized integrator can generate a 90° phase shift on the input AC sinusoidal signal by inputting the grid reference angular frequency, thereby obtaining two orthogonal signals. The grid reference angular frequency is calculated based on the grid rated frequency in the initial state, specifically:

[0047]

[0048] in, is the initial value of the grid reference angular frequency, is the rated frequency of the grid (e.g. 50Hz).

[0049] The grid reference angular frequency is calculated during the phase-locked program operation based on the current grid phase angle and the grid phase angle obtained in the previous phase-locked program operation cycle. Specifically, it is:

[0050]

[0051] in, is the grid reference angular frequency, is the current grid phase angle, is the grid phase angle of the last phase-locked program operation cycle, The calculation formula of the grid phase angle is given below.

[0052] In one embodiment, the energy storage system is a three-phase energy storage system, the grid connected to it is also a three-phase grid, and the grid voltage is a three-phase grid voltage. The specific implementation of step S101 is: performing Clarke transformation on the grid voltage to generate a set of orthogonal signals. Specifically, the calculation formula of Clarke transformation is:

[0053]

[0054] in, 、 and is the collected three-phase grid voltage, and is the generated quadrature signal.

[0055] Step S102 : obtaining a phase error between the energy storage system and the grid based on the quadrature signal and the phase reference angle in the PI controller.

[0056] In one embodiment, the specific implementation steps of step S102 include: first using the inverse tangent formula to calculate the grid phase angle based on the orthogonal signal; then subtracting the phase reference angle from the grid phase angle as the phase error between the energy storage system and the grid. Specifically, the calculation formula of the grid phase angle is:

[0057]

[0058] The calculation formula for phase error is:

[0059]

[0060] in, is the grid phase angle, is the phase error, is the phase reference angle.

[0061] In another embodiment, when the grid voltage is a three-phase grid voltage, the specific implementation steps of step S102 further include: performing a Park transform based on the orthogonal signal and the phase reference angle to obtain a d component signal and a q component signal, and using the q component signal as the phase error between the energy storage system and the grid. Specifically, the calculation formula of the Park transform is:

[0062]

[0063] in, is the d component signal, is the q component signal.

[0064] Step S103 , determining the state of the energy storage system. If the energy storage system is in an off-grid output state, a slow phase-locking strategy is executed based on the phase error; otherwise, a fast phase-locking strategy is executed based on the phase error.

[0065] Among them, the fast phase-locking strategy is to execute the PI control algorithm once in each phase-locking program operation cycle, and the slow phase-locking strategy is to execute the PI control algorithm once in N phase-locking program operation cycles. The PI control algorithm is used to obtain the PI output signal based on the phase error to update the phase reference angle, and N is an integer greater than 1.

[0066] In one embodiment, the state of the energy storage system can be determined by judging whether the output switch is turned on and whether there is an output voltage. When the output switch is turned on and there is an output voltage, it is judged that the energy storage system is in an off-grid output state; otherwise, the energy storage system is not in an off-grid output state.

[0067] In one embodiment, the PI control algorithm in the slow phase-locked strategy operates at the same frequency as the rated grid frequency, while the phase-locked program typically operates at a frequency significantly greater than the rated grid frequency. For example, if the phase-locked program operates at 1 kHz and the rated grid frequency is 50 Hz, the PI control algorithm in the slow phase-locked strategy will also operate at 50 Hz, meaning N is 20 (the PI control algorithm executes once every 20 phase-locked program runs).

[0068] In one embodiment, the N phase-locked program operation cycles in the slow phase-locked strategy include one PI controller execution cycle and (N-1) non-PI controller execution cycles. The slow phase-locked strategy is executed based on the phase error as follows: in the PI controller execution cycle, a proportional-integral operation is performed based on the phase error to obtain a PI output signal; in the non-PI controller execution cycle, the PI output signal is set to 0.

[0069] As mentioned above, the phase error can be the difference between the grid phase angle and the phase reference angle Or the q component signal , different PI output signals can be obtained by performing proportional-integral operations based on different phase errors.

[0070] In one embodiment, based on the difference between the grid phase angle and the phase reference angle The PI output signal obtained by performing proportional-integral operation is the phase correction value. The calculation formula of the phase angle correction value is:

[0071]

[0072] in, is the phase correction amount, is the PI output signal, is the first integration constant, is the first proportional constant.

[0073] Based on the phase angle correction value obtained from the above formula and the grid phase angle change step, the phase reference angle can be calculated. The calculation formula is:

[0074]

[0075] in, is the current phase reference angle, is the phase reference angle of the last phase-locked program operation cycle, is the grid phase angle change step, is the current grid phase angle, It is the grid phase angle of the last phase-locked program operation cycle.

[0076] In another embodiment, based on the q component signal The PI output signal obtained by performing proportional-integral operation is the angular frequency correction value, and the calculation formula of the angular frequency correction value is:

[0077]

[0078] in, is the angular frequency correction, is the second integration constant, is the second proportional constant.

[0079] Based on the angular frequency correction obtained from the above formula and the grid reference angular frequency, the phase reference angle can be calculated. The calculation formula is:

[0080]

[0081] in, is the grid reference angular frequency, is the rated frequency of the grid, is the angular frequency correction.

[0082] In one embodiment, a grid connection condition is preset in the energy storage system. If the current grid state meets the preset grid connection condition of the energy storage system, the phase-locking strategy is executed. Otherwise, the phase-locking strategy is not executed, and the energy storage system continues to maintain the rated amplitude and frequency. Specifically, the preset grid connection condition is that the grid voltage amplitude is near the rated voltage amplitude of the energy storage system and the grid frequency is near the rated frequency of the energy storage system. Based on this, after step S101 and before step S103, it also includes: obtaining the grid voltage amplitude and grid frequency based on the orthogonal signal; judging whether the current grid state meets the preset grid connection condition of the energy storage system based on the grid voltage amplitude and grid frequency, if so, enter step S103, if not, exit this phase-locking procedure. Specifically, if the grid voltage amplitude is near the rated voltage amplitude of the energy storage system and the grid frequency is near the rated frequency of the energy storage system, enter step S103. Among them, the calculation formulas of the grid voltage amplitude and the grid frequency are:

[0083]

[0084] in, is the grid voltage amplitude, is the grid frequency, is the grid reference angular frequency.

[0085] Please refer to Figure 2 and Figure 3 , Figure 2 This is a detailed flow chart of a phase-locking method for an energy storage system provided by an embodiment of the present invention, which is applicable to single-phase energy storage systems and three-phase energy storage systems; Figure 3 This is a detailed flow chart of a phase-locking method for a three-phase energy storage system provided by an embodiment of the present invention.

[0086] Please refer to Figure 4 , Figure 4 Schematic diagram comparing the grid voltage and output voltage when the energy storage system provided by the embodiment of the present invention switches from an off-grid loaded state to a grid connected state using a conventional software phase locking method and a phase locking method of the present application. Figure 4 It can be seen that when using conventional software phase-locking solutions, when the phase difference between the energy storage system and the grid is large, the output voltage of the energy storage system is significantly distorted when switching from an off-grid loaded state to a grid-connected state. However, the phase-locking method of this application effectively avoids this problem by adopting a slow phase-locking strategy after detecting the off-grid loaded state. Directly reducing the parameters of the PI controller to slow the phase-locking speed will make it difficult to respond quickly to dynamic changes in the grid.

[0087] The phase-locking method for an energy storage system provided in the present application first collects the grid voltage, generates a set of orthogonal signals based on the grid voltage, and obtains the phase error between the energy storage system and the grid based on the orthogonal signals and the phase reference angle in the PI controller; then determines the state of the energy storage system. If the energy storage system is in an off-grid output state, a slow phase-locking strategy is executed based on the phase error, otherwise a fast phase-locking strategy is executed based on the phase error; wherein the fast phase-locking strategy is to execute the PI control algorithm once in each phase-locking program operation cycle, and the slow phase-locking strategy is to execute the PI control algorithm once in N phase-locking program operation cycles. In the method of the present application, the phase-locked loop of the inverter continuously identifies the current working state of the energy storage system during phase locking, and selects different phase-locking frequencies for adaptive phase locking according to the current working state of the energy storage system. This method can effectively take into account various scenarios of the use of the energy storage system, and can not only achieve no significant distortion in the output voltage when the energy storage system switches from an off-grid state to a grid-connected state, thereby ensuring the safe and reliable operation of the load electrical appliances, but also make timely and rapid responses to dynamic changes in the grid voltage when connected to the grid.

[0088] According to an embodiment of the present application, an electronic device is provided, such as Figure 5 FIG. 1 is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application. The electronic device 100 includes a processor 10, a memory 20, and a communication interface 30. The processor 10, the memory 20, and the communication interface 30 are connected via a line. Figure 5 In the illustrated embodiment, the processor 10 , the memory 20 , and the communication interface 30 are communicatively connected to each other via a bus.

[0089] The memory 20 is used to store software programs, computer-executable program instructions, etc. The memory 20 may include a program storage area and a data storage area. The program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the electronic device.

[0090] The memory 20 may be a read-only memory (ROM), or other types of static storage devices that can store static information and instructions; a random access memory (RAM), or other types of dynamic storage devices that can store information and instructions; or an electrically erasable programmable read-only memory (EEPROM), and the specifics are not limited here.

[0091] Exemplarily, the memory 20 may be a double data rate synchronous dynamic random access memory (DDRSDRAM). The memory 20 may exist independently but be connected to the processor 10. Alternatively, the memory 20 may be integrated with the processor 10, for example, within one or more chips.

[0092] In some embodiments, the memory 20 may include a memory remote from the processor 10, which may be connected to the electronic device via a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0093] The processor 10 uses various interfaces and lines to connect various parts of the entire electronic device 100, and performs various functions of the electronic device and processes data by running or executing software programs stored in the memory 20, and calling data stored in the memory 20, such as implementing the method described in any embodiment of the present application.

[0094] The processor 10 may be a field programmable gate array (FPGA), a digital signal processor (DSP), a central processing unit (CPU), or the like.

[0095] The processor 10 can be a single-core processor or a multi-core processor. For example, the processor 10 can be composed of multiple FPGAs or multiple DSPs. In addition, the processor 10 can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions). The processor 10 can be a separate semiconductor chip or integrated into a semiconductor chip together with other circuits. For example, it can form a system on a chip (SoC) with other circuits (such as codec circuits, hardware acceleration circuits, or various bus and interface circuits). Alternatively, it can be integrated into an application-specific integrated circuit (ASIC) as a built-in processor of the ASIC. The ASIC with the integrated processor can be packaged separately or together with other circuits.

[0096] The communication interface 30 may use a transceiver, for example, a transceiver, to implement communication between the electronic device and other devices or a communication network.

[0097] In one embodiment, the electronic device 100 is a grid-connected inverter or a phase-locked device located in a grid-connected inverter.

[0098] The embodiment of the present application further provides a computer storage medium, which stores instructions or programs, and the instructions or programs are executed by one or more processors, such as Figure 5 A processor 10 in the embodiment may enable the one or more processors to execute the phase-locking method of the energy storage system in any of the above method embodiments.

[0099] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the relevant technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or certain portions of the embodiments.

[0100] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of variations or substitutions within the technical scope disclosed in the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A phase-locking method for an energy storage system, characterized in that: The method comprises: collecting a grid voltage and generating a set of orthogonal signals based on the grid voltage; Obtaining a phase error between the energy storage system and the power grid based on the quadrature signal and a phase reference angle in a PI controller; Determine the state of the energy storage system. If the energy storage system is in an off-grid output state, execute a slow phase-locking strategy based on the phase error; otherwise, execute a fast phase-locking strategy based on the phase error. The fast phase-locking strategy is to execute a PI control algorithm once in each phase-locking program operation cycle, and the slow phase-locking strategy is to execute a PI control algorithm once in N phase-locking program operation cycles. The PI control algorithm is used to obtain a PI output signal based on the phase error to update the phase reference angle, and N is an integer greater than 1; The PI output signal is an angular frequency correction value or a phase angle correction value. When the PI output signal is a phase angle correction value, the calculation formula of the phase reference angle is: in, is the current phase reference angle, is the phase reference angle of the last phase-locked program operation cycle, is the phase angle correction, is the grid phase angle change step, is the current grid phase angle, It is the grid phase angle of the last phase-locked program operation cycle.

2. The method according to claim 1, characterized in that The operating frequency of the PI control algorithm in the slow phase-locked strategy is the same as the rated frequency of the power grid.

3. The method according to claim 1, characterized in that The N phase-locked program operation cycles include one PI controller execution cycle and (N-1) non-PI controller execution cycles, and the execution of the slow phase-locked strategy based on the phase error includes: During the PI controller execution period, a proportional-integral operation is performed based on the phase error to obtain the PI output signal, and during the non-PI controller execution period, the PI output signal is set to 0.

4. The method according to claim 1, wherein When the PI output signal is an angular frequency correction value, the calculation formula of the phase reference angle is: in, is the grid reference angular frequency, is the rated frequency of the grid, is the angular frequency correction amount.

5. The method according to claim 1, characterized in that Before determining the state of the energy storage system, the method further includes: obtaining a grid voltage amplitude and a grid frequency based on the grid voltage; Based on the grid voltage amplitude and the grid frequency, it is determined whether the current grid state meets the preset grid connection conditions of the energy storage system. If so, the step of determining the state of the energy storage system is entered; if not, the phase-locking procedure is exited.

6. The method according to any one of claims 1 to 5, characterized in that The collecting the grid voltage and generating a set of orthogonal signals based on the grid voltage includes: When the grid voltage is a single-phase grid voltage, the grid voltage is input into an orthogonal generator to generate a set of orthogonal signals; When the grid voltage is a three-phase grid voltage, the grid voltage is subjected to Clarke transformation to generate a set of orthogonal signals.

7. The method according to claim 6, characterized in that The obtaining of the phase error between the energy storage system and the power grid based on the orthogonal signal and the phase reference angle in the PI controller includes: Calculating a grid phase angle based on the quadrature signal using an inverse tangent formula; The difference between the grid phase angle and the phase reference angle is used as the phase error between the energy storage system and the grid.

8. The method according to claim 6, characterized in that When the grid voltage is a three-phase grid voltage, obtaining the phase error between the energy storage system and the grid based on the orthogonal signal and the phase reference angle in the PI controller includes: A Park transform is performed based on the orthogonal signal and the phase reference angle to obtain a d component signal and a q component signal, and the q component signal is used as the phase error between the energy storage system and the power grid.

9. An electronic device, characterized in that: The electronic device includes at least one processor and a memory communicatively connected to the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor so as to enable the at least one processor to execute the method according to any one of claims 1 to 8.

10. A computer storage medium, characterized in that The computer storage medium stores instructions or programs, and when the instructions or programs are executed by at least one processor, the at least one processor is caused to perform the method according to any one of claims 1 to 8.

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