Method, device, electronic device and readable storage medium for determining power grid frequency

Abstract

The present application relates to the field of electronic power technology, and proposes a method, device, electronic device and readable storage medium for determining the frequency of a power grid. The method for determining the frequency of a power grid includes: obtaining a first voltage of the power grid; determining the output phase of the power grid according to the first voltage; obtaining multiple zero-crossing points of the output phase; and determining the frequency of the power grid according to the multiple zero-crossing points. The method for determining the frequency of a power grid provided in the present application can reduce interference from noise such as power grid harmonics and sampling glitches in the process of determining the output phase of the power grid, thereby ensuring that the control process has good robustness. Furthermore, the determination of the power grid frequency in combination with multiple zero-crossing points of the output phase can reduce the influence of the controller dynamics on the control process, thereby ensuring the accuracy of determining the power grid frequency.

Description

Technical Field

[0001] The present application relates to the field of electronic power technology, and in particular to a method, device, electronic device and readable storage medium for determining a power grid frequency. Background Art

[0002] In the related technology, for the calculation of grid frequency, such as according to the requirements of relevant grid-connected regulations, there are high requirements for the calculation error of grid frequency. At present, the typical methods for calculating grid frequency are based on the grid voltage zero-crossing capture method and the software phase-locked loop method. For the grid voltage zero-crossing capture method, it is easily disturbed by noise such as grid harmonics and sampling glitches, which affects the calculation accuracy. For the software phase-locked loop method, it is affected by the dynamics of the controller, and the output frequency fluctuates greatly, which cannot meet the accuracy requirements of grid frequency calculation. Summary of the invention

[0003] The present application aims to at least solve the technical problem of poor accuracy in calculating power grid frequency in the prior art.

[0004] To this end, a first aspect of the present application is to propose a method for determining a grid frequency.

[0005] A second aspect of the present application is to provide a device for determining a power grid frequency.

[0006] A third aspect of the present application is to provide an electronic device.

[0007] A fourth aspect of the present application is to provide a readable storage medium.

[0008] In view of this, according to the first aspect of the present application, a method for determining the frequency of a power grid is proposed, including: obtaining a first voltage of the power grid; determining the output phase of the power grid based on the first voltage; obtaining multiple zero-crossing points of the output phase; and determining the frequency of the power grid based on the multiple zero-crossing points.

[0009] The method for determining the power grid frequency provided by the present application, in the process of determining the power grid frequency, first, obtains the first voltage of the power grid, and then determines the output phase of the power grid according to the first voltage. Further, after determining the output phase of the power grid, multiple zero-crossing points through which the output phase passes can be obtained. It can be understood that the voltage of the power grid changes periodically. During the process of voltage change, the output voltage of the power grid changes between positive and negative values ​​over time. In each change cycle, the output voltage will pass through a zero point where the voltage changes from a negative value to a positive value, that is, the zero-crossing point of the output phase. During a period of operation of the power grid, the output phase will pass through multiple zero-crossing points. After determining the output phase of the power grid, multiple zero-crossing points of the power grid during a period of operation can be obtained.

[0010] Further, after obtaining multiple zero-crossing points of the output phase, the power grid frequency can be determined according to the multiple zero-crossing points. That is, in the process of determining the power grid frequency, the determination method of the output phase of the power grid is combined with the zero-crossing capture method to determine the power grid frequency. Compared with the power grid voltage zero-crossing capture method in the related art, the determination process of the output phase of the power grid is less disturbed by noise such as power grid harmonics and sampling glitches, the determination accuracy can be guaranteed, and the control process has good robustness. At the same time, the determination of the power grid frequency in combination with the multiple zero-crossing points of the output phase can reduce the influence of the controller dynamics on the control process, thereby ensuring the determination accuracy of the power grid frequency.

[0011] The method for determining the grid frequency provided by the present application first determines the output phase of the grid according to the first voltage of the grid, then obtains multiple zero-crossing points of the output phase, and then determines the grid frequency according to the multiple zero-crossing points of the output phase. Thus, in the process of determining the output phase of the grid, the interference of noise such as grid harmonics and sampling glitches can be reduced, and the control process can be ensured to have good robustness. Furthermore, the determination of the grid frequency in combination with the multiple zero-crossing points of the output phase can reduce the influence of the controller dynamics on the control process, and thus ensure the determination accuracy of the grid frequency.

[0012] In some technical solutions, optionally, determining the grid frequency based on multiple zero-crossing points includes: acquiring a first time duration passed by the multiple zero-crossing points; and determining the grid frequency based on the first time duration and the number of zero-crossing points.

[0013] In some technical solutions, optionally, obtaining multiple zero-crossing points of the output phase includes: obtaining the rated frequency of the power grid; determining the number of zero-crossing points based on the rated frequency; and obtaining multiple zero-crossing points based on the number of zero-crossing points.

[0014] In some technical solutions, optionally, determining the output phase of the power grid according to the first voltage includes: constructing an orthogonal component of the first voltage according to the first voltage; determining the output angular frequency of the power grid according to the orthogonal component; and determining the output phase of the power grid according to the output angular frequency.

[0015] In some technical solutions, optionally, constructing a quadrature component of the first voltage according to the first voltage includes: inputting the first voltage into a second-order generalized integrator to generate the quadrature component.

[0016] In some technical schemes, optionally, the output angular frequency of the power grid is determined based on the orthogonal components, including: performing coordinate transformation on the orthogonal components to generate a control quantity corresponding to the first voltage; determining an error signal based on the control quantity and a preset value; inputting the error signal into a linear controller to generate the actual frequency of the power grid; and determining the output angular frequency based on the actual frequency and the rated frequency of the power grid.

[0017] In some technical solutions, optionally, the output phase of the power grid is determined according to the output angular frequency, including: inputting the output angular frequency into an integrator to generate a first phase intermediate value; dividing the first phase intermediate value by 2π and taking the remainder to generate the output phase.

[0018] According to the second aspect of the present application, a device for determining the frequency of a power grid is proposed, comprising: an acquisition unit for acquiring a first voltage of the power grid; a determination unit for determining the output phase of the power grid based on the first voltage; the acquisition unit is also used to acquire multiple zero-crossing points of the output phase; the determination unit is also used to determine the frequency of the power grid based on the multiple zero-crossing points.

[0019] The power grid frequency determination device provided by the present application first determines the output phase of the power grid according to the first voltage of the power grid, then obtains multiple zero-crossing points of the output phase, and then determines the power grid frequency according to the multiple zero-crossing points of the output phase. Therefore, in the process of determining the output phase of the power grid, the interference of noise such as power grid harmonics and sampling glitches can be reduced, and the control process can be ensured to have good robustness. Furthermore, the power grid frequency can be determined in combination with the multiple zero-crossing points of the output phase, which can reduce the influence of the controller dynamics on the control process, and thus ensure the accuracy of the determination of the power grid frequency.

[0020] In some technical solutions, optionally, the determination unit is specifically used to: obtain a first time duration passed by multiple zero-crossing points; and determine the grid frequency according to the first time duration and the number of zero-crossing points.

[0021] In some technical solutions, optionally, the acquisition unit is specifically used to: acquire the rated frequency of the power grid; determine the number of zero-crossing points according to the rated frequency; and acquire multiple zero-crossing points according to the number of zero-crossing points.

[0022] In some technical solutions, optionally, the determination unit is further used to: construct an orthogonal component of the first voltage according to the first voltage; determine an output angular frequency of the power grid according to the orthogonal component; and determine an output phase of the power grid according to the output angular frequency.

[0023] In some technical solutions, optionally, the determination unit is further configured to: input the first voltage to a second-order generalized integrator to generate an orthogonal component.

[0024] In some technical schemes, optionally, the determination unit is also specifically used to: perform coordinate transformation on the orthogonal components to generate a control quantity corresponding to the first voltage; determine an error signal based on the control quantity and a preset value; input the error signal to a linear controller to generate an actual frequency of the power grid; determine the output angular frequency based on the actual frequency and the rated frequency of the power grid.

[0025] In some technical solutions, optionally, the determination unit is further used to: input the output angular frequency to an integrator to generate a first phase intermediate value; and multiply the first phase intermediate value by 2π and take the remainder to generate an output phase.

[0026] According to the third aspect of the present application, an electronic device is proposed, comprising: a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method for determining the grid frequency in any one of the above technical solutions are implemented. Therefore, the electronic device has all the beneficial effects of the method for determining the grid frequency in any one of the above technical solutions, which will not be described in detail here.

[0027] According to the fourth aspect of the present application, a readable storage medium is provided, on which a program or instruction is stored, and when the program or instruction is executed by a processor, a method for determining the grid frequency in any of the above technical solutions is implemented. Therefore, the readable storage medium has all the beneficial effects of the method for determining the grid frequency in any of the above technical solutions, which will not be described in detail here.

[0028] Additional aspects and advantages of the present application will become apparent in the following description or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 A schematic diagram showing a flow chart of a method for determining a power grid frequency according to an embodiment of the present application is shown;

[0031] Figure 2 A circuit diagram is shown for use in a method for determining a power grid frequency according to an embodiment of the present application;

[0032] Figure 3 shows a curve showing a change in the voltage of the power grid in an embodiment of the present application;

[0033] Figure 4 The output phase variation curve of the power grid in the embodiment of the present application is shown;

[0034] Figure 5 A structural block diagram of a device for determining a power grid frequency according to an embodiment of the present application is shown;

[0035] Figure 6 A structural block diagram of an electronic device according to an embodiment of the present application is shown.

[0036] Reference numerals:

[0037] 400 is a device for determining a grid frequency, 402 is an acquisition unit, 404 is a determination unit, 500 is an electronic device, 502 is a processor, and 504 is a memory. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0040] Combine the following Figures 1 to 6 , the method, device, electronic device and readable storage medium for determining the power grid frequency provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0041] like Figure 1 As shown, in an embodiment of the present application, a method for determining a power grid frequency is provided, comprising:

[0042] Step 102, obtaining a first voltage of a power grid;

[0043] Step 104, determining an output phase of the power grid according to the first voltage;

[0044] Step 106, obtaining multiple zero-crossing points of the output phase;

[0045] Step 108, determining the grid frequency according to the multiple zero-crossing points.

[0046] The method for determining the grid frequency provided in the present application, in the process of determining the grid frequency, firstly, obtains the first voltage of the grid, and then determines the output phase of the grid according to the first voltage. Further, after determining the output phase of the grid, multiple zero crossing points passed by the output phase can be obtained. It can be understood that, if Figure 3 As shown in the figure, the voltage of the power grid changes periodically. During the voltage change, the power grid output changes between positive and negative values ​​over time. At the same time, the output phase changes from 0 to 2π. During the operation of the power grid for a period of time, the output phase will pass through multiple zero crossing points, and the time between two adjacent zero crossing points is dT. Correspondingly, the output phase of the power grid changes with time as shown in the figure below: Figure 4 After the output phase of the power grid is determined, multiple zero-crossing points of the power grid within a period of operation can be obtained.

[0047] Further, after obtaining multiple zero-crossing points of the output phase, the power grid frequency can be determined according to the multiple zero-crossing points. That is, in the process of determining the power grid frequency, the determination method of the output phase of the power grid is combined with the zero-crossing capture method to determine the power grid frequency. Compared with the power grid voltage zero-crossing capture method in the related art, the determination process of the output phase of the power grid is less disturbed by noise such as power grid harmonics and sampling glitches, the determination accuracy can be guaranteed, and the control process has good robustness. At the same time, the determination of the power grid frequency in combination with the multiple zero-crossing points of the output phase can reduce the influence of the controller dynamics on the control process, thereby ensuring the determination accuracy of the power grid frequency.

[0048] The method for determining the grid frequency provided by the present application first determines the output phase of the grid according to the first voltage of the grid, then obtains multiple zero-crossing points of the output phase, and then determines the grid frequency according to the multiple zero-crossing points of the output phase. Thus, in the process of determining the output phase of the grid, the interference of noise such as grid harmonics and sampling glitches can be reduced, and the control process can be ensured to have good robustness. Furthermore, the determination of the grid frequency in combination with the multiple zero-crossing points of the output phase can reduce the influence of the controller dynamics on the control process, and thus ensure the determination accuracy of the grid frequency.

[0049] In some embodiments, optionally, determining the grid frequency based on multiple zero-crossing points includes: acquiring a first time duration passed by the multiple zero-crossing points; and determining the grid frequency based on the first time duration and the number of zero-crossing points.

[0050] In this embodiment, after the output phase of the power grid is determined according to the first voltage of the power grid, in order to avoid the inability to meet the determination accuracy of the power grid frequency due to the influence of the controller dynamics in the process of determining the power grid frequency, the error of the output phase of the power grid can be averaged over multiple cycles, that is, according to multiple zero crossing points, the error of the output phase of the power grid can be averaged over multiple cycles, and then in the process of determining the power grid frequency according to multiple zero crossing points, the calculation accuracy specified in the relevant regulatory requirements can be met.

[0051] Specifically, after determining the output phase of the power grid, a first duration of multiple zero crossings of the output phase is obtained, and then the power grid frequency is determined according to the first duration and the number of zero crossings. Specifically, the first duration can be divided by the number of zero crossings to obtain the power grid frequency.

[0052] Exemplarily, according to the requirements of relevant laws and regulations, the calculation accuracy of the power grid frequency needs to be within 10mHz. Taking the rated frequency of the power grid as 50Hz as an example, it is necessary to ensure that the calculation accuracy of the power grid frequency reaches 0.2%. In the process of determining the output phase of the power grid according to the first voltage of the power grid, the software phase-locked loop method can be used for determination. The accuracy of the output phase determined by the software phase-locked loop method can generally reach 0.5%, and this accuracy cannot guarantee the calculation accuracy of the power grid frequency. Therefore, 25 zero-crossing points of the output phase can be obtained, so that the error of 0.5% of the output phase is evenly distributed in 25 cycles, and then the accuracy of 0.2% can be achieved. Finally, the first duration of the 25 zero-crossing points of the output phase is determined, and the first duration is divided by 25 to obtain the power grid frequency, which can meet the accuracy requirement of 0.2%.

[0053] In some embodiments, optionally, obtaining multiple zero-crossing points of the output phase includes: obtaining a rated frequency of the power grid; determining the number of zero-crossing points based on the rated frequency; and obtaining multiple zero-crossing points based on the number of zero-crossing points.

[0054] In this embodiment, in the process of determining multiple zero-crossing points of the output phase, the rated frequency of the power grid needs to be obtained first. It can be understood that according to the requirements of relevant laws and regulations, the calculation accuracy of the power grid frequency needs to be within 10mHz. Therefore, for power grids with different rated frequencies, in order to meet the calculation accuracy of the power grid frequency, the number of zero-crossing points required to be obtained is not the same.

[0055] Taking the rated frequency of the power grid as 50Hz as an example, the calculation accuracy of the power grid frequency needs to be within 10mHz, so when calculating the power grid frequency of the power grid, it is necessary to achieve an accuracy requirement of 0.2%. Accordingly, since the accuracy of determining the output phase of the power grid according to the first voltage can only reach 0.5%, based on the accuracy requirement of 0.2%, it is necessary to spread the error of 0.5% over at least 25 cycles, that is, the number of zero crossing points of the output phase needs to be at least 25.

[0056] In addition, it should be noted that the number of zero-crossing points of the output phase needs to be less than 60, so as to meet the requirement stipulated in relevant laws and regulations that the calculation time of the power grid frequency needs to be within 60 cycles.

[0057] In some embodiments, optionally, determining the output phase of the power grid according to the first voltage includes: constructing an orthogonal component of the first voltage according to the first voltage; determining the output angular frequency of the power grid according to the orthogonal component; and determining the output phase of the power grid according to the output angular frequency.

[0058] In this embodiment, a software phase-locked loop method can be used to determine the output phase of the power grid. Specifically, after obtaining the first voltage of the power grid, the orthogonal components of the first voltage can be constructed first, and then the output angular frequency of the power grid can be determined based on the constructed orthogonal components. Finally, the output phase of the power grid can be determined based on the output angular frequency of the power grid.

[0059] Further, constructing a quadrature component of the first voltage according to the first voltage includes: inputting the first voltage into a second order generalized integrator (SOGI) to generate the quadrature component.

[0060] Specifically, Figure 2 As shown, in the process of constructing the orthogonal components of the first voltage, the orthogonal components of the first voltage can be constructed by a second-order generalized integration method. That is, the first voltage can be input into a second-order generalized integrator, so that the first voltage Vs is constructed into an α component Vα and a β component Vβ.

[0061] Furthermore, the output angular frequency of the power grid is determined based on the orthogonal components, including: performing coordinate transformation on the orthogonal components to generate a control quantity corresponding to the first voltage; determining an error signal based on the control quantity and a preset value; inputting the inverse of the control quantity into a linear controller to generate an actual frequency of the power grid; and determining the output angular frequency based on the actual frequency and the rated frequency of the power grid.

[0062] Specifically, after constructing the orthogonal components of the first voltage, the output angular frequency of the power grid can be determined according to the orthogonal components of the first voltage. Specifically, firstly, the orthogonal components can be transformed by coordinate transformation to generate the control amount corresponding to the first voltage.

[0063] Specifically, Figure 2 As shown, the first voltage Vs is constructed into an α component Vα and a β component Vβ. Then, the coordinates of Vα and Vβ can be transformed by park transformation to generate the control quantity corresponding to the first voltage, that is, to generate the direct-axis voltage Vd and the quadrature-axis voltage Vq corresponding to the first voltage.

[0064] Furthermore, if Figure 2 As shown, according to the control amount corresponding to the first voltage and the preset value, the error signal of the first voltage can be determined. Specifically, in the actual control process, the preset value can be 0, that is, only the difference between 0 and the direct axis voltage Vq is calculated to determine the error signal of the first voltage.

[0065] Furthermore, the error signal is input into a proportional integral controller (PI) to generate the actual frequency of the power grid. Finally, the output angular frequency of the power grid can be determined based on the actual frequency of the power grid and the rated frequency of the power grid. Specifically, Figure 2 As shown, the actual frequency of the power grid can be superimposed on the rated frequency ω0 of the power grid to obtain the output cross frequency of the power grid.

[0066] Furthermore, the output phase of the power grid is determined according to the output angular frequency, including: inputting the output angular frequency into an integrator to generate an intermediate value of the first phase; dividing the first phase intermediate value by 2π and taking the remainder to generate the output phase.

[0067] Specifically, Figure 2 As shown, after the output angular frequency of the power grid is determined, the output angular frequency of the power grid can be input into an integrator for integration calculation to generate a first phase intermediate value, and then the first phase intermediate value is divided by 2π and the remainder is taken to obtain the output phase of the power grid.

[0068] Finally, if Figure 2 As shown, the N zero-crossing points of the output phase of the power grid can be recorded by relevant software, and the first time length dT passed by the N zero-crossing points can be obtained, and then the number N of zero-crossing points in the first time length dT can be used to obtain the power grid frequency f.

[0069] In some embodiments, optionally, Figure 5 As shown, a device 400 for determining the frequency of a power grid is provided, comprising: an acquisition unit 402, used to acquire a first voltage of the power grid; a determination unit 404, used to determine the output phase of the power grid according to the first voltage; the acquisition unit 402 is also used to acquire multiple zero-crossing points of the output phase; the determination unit 404 is also used to determine the frequency of the power grid according to the multiple zero-crossing points.

[0070] The power grid frequency determination device 400 provided in the present application first determines the output phase of the power grid according to the first voltage of the power grid, then obtains multiple zero-crossing points of the output phase, and then determines the power grid frequency according to the multiple zero-crossing points of the output phase. Thus, in the process of determining the output phase of the power grid, the interference of noise such as power grid harmonics and sampling glitches can be reduced, and the control process can be ensured to have good robustness. Furthermore, the power grid frequency can be determined in combination with the multiple zero-crossing points of the output phase, which can reduce the influence of the controller dynamics on the control process, and thus ensure the accuracy of the determination of the power grid frequency.

[0071] Further, the determination unit 404 is specifically configured to: obtain a first time duration during which a plurality of zero-crossing points pass; and determine the grid frequency according to the first time duration and the number of zero-crossing points.

[0072] Further, the acquisition unit 402 is specifically used to: acquire the rated frequency of the power grid; determine the number of zero-crossing points according to the rated frequency; and acquire multiple zero-crossing points according to the number of zero-crossing points.

[0073] Furthermore, the determination unit 404 is specifically configured to: construct an orthogonal component of the first voltage according to the first voltage; determine an output angular frequency of the power grid according to the orthogonal component; and determine an output phase of the power grid according to the output angular frequency.

[0074] Furthermore, the determining unit 404 is further specifically configured to: input the first voltage into a second-order generalized integrator to generate an orthogonal component.

[0075] Furthermore, the determination unit 404 is specifically used to: perform coordinate transformation on the orthogonal components to generate a control quantity corresponding to the first voltage; determine an error signal based on the control quantity and a preset value; input the error signal to a linear controller to generate an actual frequency of the power grid; and determine the output angular frequency based on the actual frequency and the rated frequency of the power grid.

[0076] Furthermore, the determination unit 404 is specifically configured to: input the output angular frequency to an integrator to generate a first phase intermediate value; divide the first phase intermediate value by 2π and take the remainder to generate an output phase.

[0077] In some embodiments, optionally, Figure 6 As shown, an electronic device 500 is proposed, including: a processor 502 and a memory 504, the memory 504 stores a program or instruction that can be run on the processor 502, and the program or instruction is executed by the processor 502 to implement the steps of the method for determining the grid frequency in any of the above technical solutions. Therefore, the electronic device 500 has all the beneficial effects of the method for determining the grid frequency in any of the above technical solutions, which will not be repeated here.

[0078] In some embodiments, optionally, a readable storage medium is provided, on which a program is stored. When the program is executed by a processor, the method for determining the grid frequency in any of the above embodiments is implemented, thereby having all the beneficial technical effects of the method for determining the grid frequency in any of the above embodiments.

[0079] The readable storage medium includes a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0080] It should be clarified that in the claims, specification and drawings of the present application, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings, which is only for the purpose of more conveniently describing the present application and making the description process easier, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation, so these descriptions cannot be understood as limitations on the present application; the terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood based on the specific circumstances of the above data.

[0081] In the claims, specification and drawings of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the claims, specification and drawings of the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0082] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining a power grid frequency, characterized in that: include: Acquiring a first voltage of a power grid; determining an output phase of the power grid according to the first voltage; Acquire multiple zero-crossing points of the output phase; The grid frequency is determined according to the plurality of zero crossing points.

2. The determination method according to claim 1, characterized in that: The step of determining the grid frequency according to the plurality of zero crossing points comprises: Obtaining a first duration of a plurality of zero-crossing points; The grid frequency is determined according to the first time duration and the number of the zero crossing points.

3. The determination method according to claim 1, characterized in that: The obtaining of a plurality of zero-crossing points of the output phase comprises: Obtaining the rated frequency of the power grid; Determining the number of the zero crossing points according to the rated frequency; According to the number of the zero-crossing points, a plurality of the zero-crossing points are obtained.

4. The determination method according to any one of claims 1 to 3, characterized in that: The step of determining the output phase of the power grid according to the first voltage includes: constructing a quadrature component of the first voltage based on the first voltage; Determining the output angular frequency of the power grid according to the orthogonal components; An output phase of the power grid is determined according to the output angular frequency.

5. The determination method according to claim 4, characterized in that: The step of constructing a quadrature component of the first voltage according to the first voltage includes: The first voltage is input to a second-order generalized integrator to generate the quadrature component.

6. The determination method according to claim 4, characterized in that: Determining the output angular frequency of the power grid according to the orthogonal components includes: Performing coordinate transformation on the orthogonal components to generate a control amount corresponding to the first voltage; Determining an error signal according to the control amount and a preset value; Inputting the error signal into a linear controller to generate an actual frequency of the power grid; The output angular frequency is determined according to the actual frequency and the rated frequency of the power grid.

7. The determination method according to claim 4, characterized in that: Determining the output phase of the power grid according to the output angular frequency includes: Inputting the output angular frequency into an integrator to generate a first phase intermediate value; The first phase intermediate value is divided by 2π and the remainder is obtained to generate the output phase.

8. A device for determining a power grid frequency, characterized in that: include: An acquisition unit, used for acquiring a first voltage of a power grid; a determining unit, configured to determine an output phase of the power grid according to the first voltage; The acquisition unit is also used to acquire a plurality of zero-crossing points of the output phase; The determining unit is further configured to determine the grid frequency according to the plurality of zero-crossing points.

9. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a program or an instruction, and when the program or the instruction is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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