Grid voltage sag detection method, device, electronic device and storage medium

Abstract

The present application discloses a method, device, electronic device, and storage medium for detecting grid voltage sags. The method and device specifically comprise the following steps: obtaining the real-time voltage value of any phase of the grid to be tested; performing waveform fitting based on the real-time voltage value to obtain the fitted voltage value of any phase; performing a difference operation on the real-time voltage value and the fitted voltage value to obtain the real-time difference between the real-time voltage value and the fitted voltage value; constructing a critical range of normal voltage of any phase based on the real-time difference; monitoring the real-time difference based on the critical range, and determining that a voltage sag has occurred in the grid to be tested when the difference exceeds the critical range. By effectively detecting the occurrence of a voltage sag, a dynamic voltage restorer can be enabled to quickly disconnect the grid when a voltage sag occurs.

Description

Technical Field

[0001] The present application relates to the technical field of power equipment, and more specifically, to a method, device, electronic device, and storage medium for detecting grid voltage sag. Background Art

[0002] For semiconductor manufacturers, which are particularly sensitive to grid voltage sags, even a voltage sag of just a few tens of milliseconds can result in significant economic losses. These manufacturers utilize intelligent and automated processing equipment. To achieve flexible and controllable production, they often use inverters to drive AC loads, or convert AC to DC to drive DC loads. To ensure continuous power supply to loads during production, dynamic voltage restorers are often installed to prevent power outages caused by external factors. To minimize the impact of abnormal grid voltage on the load, it is essential to disconnect the grid as quickly as possible and switch to a dynamic voltage restorer. Whether the dynamic voltage restorer can compensate for the grid voltage sag depends on its ability to quickly and accurately detect the grid voltage sag. Summary of the Invention

[0003] In view of this, the present application provides a method, device, electronic device and storage medium for detecting grid voltage sag, which are used to effectively detect grid voltage sag so that a dynamic voltage restorer can quickly cut off the grid when a voltage sag occurs.

[0004] In order to achieve the above objectives, the following solutions are proposed:

[0005] A method for detecting a grid voltage sag is applied to electronic equipment, and the method comprises the following steps:

[0006] Obtain the real-time voltage value of any phase of the power grid to be tested;

[0007] Performing waveform fitting according to the real-time voltage value to obtain a fitting voltage value of any phase;

[0008] performing a difference operation on the real-time voltage value and the fitted voltage value to obtain a real-time difference between the real-time voltage value and the fitted voltage value;

[0009] Establishing a critical range of a normal voltage of any phase according to the real-time difference;

[0010] The real-time difference is monitored based on the critical range, and when the difference exceeds the critical range, it is determined that a voltage sag occurs in the power grid to be measured.

[0011] Optionally, performing waveform fitting according to the real-time voltage value to obtain the fitted voltage value of any phase includes the steps of:

[0012] Detecting a phase-locked angle of the real-time voltage value;

[0013] Calculating the effective value of the real-time voltage value;

[0014] A waveform fitting is performed according to the phase-locked angle and the effective value to obtain the fitted voltage value.

[0015] Optionally, sliding window filtering is performed on the real-time voltage value during the calculation of the effective value.

[0016] Optionally, the monitoring of the real-time difference based on the critical range and determining that a voltage sag occurs in the power grid to be measured when the real-time difference exceeds the critical range comprises the steps of:

[0017] monitoring the difference based on the critical range, and when the real-time difference exceeds the critical range, monitoring a continuous duration of the real-time difference exceeding the critical range;

[0018] When the continuous duration reaches a preset duration threshold, it is determined that a voltage sag occurs in the power grid to be measured.

[0019] A detection device for a grid voltage sag, applied to electronic equipment, comprising:

[0020] A voltage value acquisition module is configured to obtain a real-time voltage value of any phase of the power grid to be tested;

[0021] a waveform fitting module, configured to perform waveform fitting according to the real-time voltage value to obtain a fitting voltage value of any phase;

[0022] a difference calculation module, configured to perform a difference operation on the real-time voltage value and the fitted voltage value to obtain a real-time difference between the real-time voltage value and the fitted voltage value;

[0023] a range building module configured to build a critical range of the normal voltage of any phase according to the real-time difference;

[0024] The detection execution module is configured to monitor the real-time difference based on the critical range, and determine that a voltage sag occurs in the power grid to be tested when the real-time difference exceeds the critical range.

[0025] Optionally, the waveform fitting module includes:

[0026] a phase-lock angle detection unit, configured to detect a phase-lock angle of the real-time voltage value;

[0027] an effective value calculation unit, configured to calculate an effective value of the real-time voltage value;

[0028] The fitting execution unit is configured to perform waveform fitting according to the phase-locked angle and the effective value to obtain the fitting voltage value.

[0029] Optionally, the effective value calculation unit performs sliding window filtering on the real-time voltage value during the process of calculating the effective value.

[0030] Optionally, the detection execution module includes:

[0031] a difference monitoring unit configured to monitor the real-time difference based on the critical range, and when the real-time difference exceeds the critical range, monitor a continuous duration of the real-time difference exceeding the critical range;

[0032] The judgment execution unit is configured to determine that a voltage sag occurs in the power grid to be measured when the continuous duration reaches a preset duration threshold.

[0033] An electronic device, applied to a dynamic voltage restorer, includes at least one processor and a memory connected to the processor, wherein:

[0034] The memory is used to store computer programs or instructions;

[0035] The processor is used to execute the computer program or instruction to enable the electronic device to implement the above-mentioned method for detecting grid voltage sag.

[0036] A storage medium is applied to an electronic device, the storage medium carrying one or more computer programs. When the electronic device executes the one or more computer programs, the electronic device can implement the above-mentioned method for detecting temporary voltage sag in the power grid.

[0037] As can be seen from the above technical solution, the present application discloses a method, device, electronic device and storage medium for detecting grid voltage sag. The method and device specifically obtain the real-time voltage value of any phase of the grid to be tested; perform waveform fitting based on the real-time voltage value to obtain the fitted voltage value of any phase; perform difference calculation on the real-time voltage value and the fitted voltage value to obtain the real-time difference between the real-time voltage value and the fitted voltage value; construct a critical range of normal voltage of any phase based on the real-time difference; monitor the real-time difference based on the critical range, and when the difference exceeds the critical range, determine that a voltage sag has occurred in the grid to be tested. By effectively detecting the occurrence of voltage sag, the dynamic voltage restorer can quickly cut off the grid when a voltage sag occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0039] Figure 1 This is a flow chart of a method for detecting a grid voltage sag according to an embodiment of the present application;

[0040] Figure 2 This is a block diagram of a device for detecting a grid voltage sag according to an embodiment of the present application;

[0041] Figure 3 This is a block diagram of another device for detecting grid voltage sag according to an embodiment of the present application;

[0042] Figure 4 This is a block diagram of another device for detecting grid voltage sag according to an embodiment of the present application;

[0043] Figure 5 This is a block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] Example 1

[0046] Figure 1 This is a flow chart of a method for detecting grid voltage sag according to an embodiment of the present application.

[0047] like Figure 1 As shown, the detection method provided in this embodiment is applied to an electronic device for detecting a voltage sag occurring in a power grid, so as to provide a data basis for determining whether a dynamic voltage restorer performs compensation. The electronic device herein refers to a computer or server with data computing and information processing capabilities. The detection method includes the following steps:

[0048] S1. Obtain the real-time voltage value of any phase of the power grid to be tested.

[0049] For any phase or each phase of the power grid to be tested, the real-time voltage value of the phase or each phase collected by the voltage sensor installed thereon is obtained. The real-time voltage value is a line voltage value or a phase voltage value. In this embodiment, the phase voltage value is preferred.

[0050] S2. Perform waveform fitting on the real-time voltage value to obtain a fitted voltage value.

[0051] That is, the real-time voltage value is fitted to obtain a fitting waveform corresponding to the real-time voltage value. The fitting voltage value here refers to the voltage value corresponding to the fitting waveform at the current moment. The specific process is:

[0052] First, the phase-locked angle of the real-time voltage value is detected.

[0053] Then, the effective value of the real-time voltage value is calculated. During the calculation of the effective value, a sliding window filtering process is performed on the real-time voltage value, and the effective value of the real-time voltage value is obtained based on the sliding window filtering process.

[0054] Finally, waveform fitting is performed based on the phase-locked angle and the effective value to obtain a fitted waveform, which includes a series of fitted voltage values. Because the phase-locked angle is the real-time angle of the fundamental wave, the fitted waveform is the effective value of the fundamental wave waveform, that is, a 50Hz or 60Hz sine curve. The effective value of this curve varies slightly with the increase of harmonic content. The fitted waveform is exactly the center point of the system grid voltage envelope in the case of high harmonic distortion.

[0055] S3. Calculate the real-time difference between the real-time voltage value and the fitted voltage value.

[0056] That is, the difference between the real-time voltage value and the fitted voltage value is calculated. Since it is derived from the real-time value, it is described as a real-time difference.

[0057] S4. Construct a critical range based on the real-time difference.

[0058] After obtaining a series of real-time differences, a critical range is constructed based on these differences. When the power grid is normal, the difference between two instantaneous waveforms over the entire power frequency cycle forms a stripline, with the upper and lower boundaries of the stripline forming the critical range. The upper boundary of the stripline represents the critical line for normal voltage. The critical line's size is independent of the power grid voltage level, significantly enhancing detection consistency.

[0059] S5. Monitor the real-time difference based on the critical range.

[0060] That is, the real-time difference is monitored to determine whether it exceeds the critical range and lasts for a sufficient period of time.

[0061] The real-time difference is monitored based on the critical range. When the real-time difference exceeds the critical range, the duration of the real-time difference exceeding the critical range is monitored. If the duration is short, it is not considered that a voltage sag has occurred.

[0062] If the duration of the continuous sag is long, specifically reaching or exceeding a preset duration threshold, it is determined that a voltage sag has occurred in the power grid under test. The preset duration threshold here needs to be determined according to specific parameters of the dynamic voltage restorer.

[0063] As can be seen from the above technical solution, this embodiment provides a method for detecting grid voltage sags, which is applied to electronic equipment and specifically comprises the following steps: obtaining the real-time voltage value of any phase of the grid to be tested; performing waveform fitting based on the real-time voltage value to obtain the fitted voltage value of any phase; performing a difference operation on the real-time voltage value and the fitted voltage value to obtain the real-time difference between the real-time voltage value and the fitted voltage value; constructing a critical range of normal voltage of any phase based on the real-time difference; monitoring the real-time difference based on the critical range, and determining that a voltage sag has occurred in the grid to be tested when the difference exceeds the critical range. By effectively detecting the occurrence of voltage sags, the dynamic voltage restorer can quickly cut off the grid when a voltage sag occurs.

[0064] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the module, program segment, or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0065] Although the operations are depicted in a particular order, this should not be understood as requiring that the operations be performed in the particular order shown or in a sequential order.Multitasking and parallel processing may be advantageous under certain circumstances.

[0066] It should be understood that the various steps described in the method embodiments of the present disclosure may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this respect.

[0067] Computer program code for performing the operations of the present disclosure may be written in one or more programming languages, or a combination thereof, including, but not limited to, object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer.

[0068] Example 2

[0069] Figure 2 This is a block diagram of a grid voltage sag detection device according to an embodiment of the present application.

[0070] like Figure 2 As shown, the detection device provided in this embodiment is applied to an electronic device for detecting a voltage sag occurring in a power grid, so as to provide a data basis for whether a dynamic voltage restorer performs compensation. The electronic device here refers to a computer or server with data computing and information processing capabilities. The detection device includes a voltage value acquisition module 10, a waveform fitting module 20, a difference calculation module 30, a range construction module 40 and a detection execution module 50.

[0071] The voltage value acquisition module is used to obtain the real-time voltage value of any phase of the power grid to be tested.

[0072] For any phase or each phase of the power grid to be tested, the real-time voltage value of the phase or each phase collected by the voltage sensor installed thereon is obtained. The real-time voltage value is a line voltage value or a phase voltage value. In this embodiment, the phase voltage value is preferred.

[0073] The waveform fitting module is used to perform waveform fitting on the real-time voltage value to obtain a fitted voltage value.

[0074] That is, the real-time voltage value is fitted to obtain a fitting waveform corresponding to the real-time voltage value. The fitting voltage value here refers to the voltage value corresponding to the fitting waveform at the current moment. The module includes a phase-locked angle detection unit 21, an effective value calculation unit 22 and a fitting execution unit 23. Figure 3 shown.

[0075] The phase-lock angle detection unit is used to detect the phase-lock angle of the real-time voltage value.

[0076] The effective value calculation unit is used to calculate the effective value of the real-time voltage value. During the calculation of the effective value, the real-time voltage value is subjected to sliding window filtering, and the effective value of the real-time voltage value is obtained based on the sliding window filtering.

[0077] The fitting execution unit is configured to perform waveform fitting based on the phase-locked angle and the effective value to obtain a fitted waveform, which includes a series of fitted voltage values. Because the phase-locked angle is the real-time angle of the fundamental wave, the fitted waveform is the effective value fundamental waveform, i.e., a 50Hz or 60Hz sine curve. The effective value of this curve varies slightly with increasing harmonic content. The fitted waveform is precisely the center point of the system grid voltage envelope in the case of high harmonic distortion.

[0078] The difference calculation module is used to calculate the real-time difference between the real-time voltage value and the fitted voltage value.

[0079] That is, the difference between the real-time voltage value and the fitted voltage value is calculated. Since it is derived from the real-time value, it is described as a real-time difference.

[0080] The range building module is used to build a critical range based on real-time difference values.

[0081] After obtaining a series of real-time differences, a critical range is constructed based on these differences. When the power grid is normal, the difference between two instantaneous waveforms over the entire power frequency cycle forms a stripline, with the upper and lower boundaries of the stripline forming the critical range. The upper boundary of the stripline represents the critical line for normal voltage. The critical line's size is independent of the power grid voltage level, significantly enhancing detection consistency.

[0082] The detection execution module is used to monitor the real-time difference based on the critical range.

[0083] That is, the real-time difference is monitored to determine whether it exceeds the critical range and lasts for a sufficient period of time. The module specifically includes a difference monitoring unit 51 and a judgment execution unit 52, such as Figure 4 shown.

[0084] The monitoring execution unit is configured to monitor the real-time difference based on the critical range, and when the real-time difference exceeds the critical range, monitor the duration of the real-time difference exceeding the critical range. If the duration is short, no voltage sag is considered to have occurred.

[0085] The judgment execution unit is used to determine that a voltage sag occurs in the power grid under test if the continuous duration is long, specifically reaching or exceeding a preset duration threshold. The preset duration threshold here needs to be determined according to the specific parameters of the dynamic voltage restorer.

[0086] As can be seen from the above technical solution, this embodiment provides a detection device for grid voltage sag, which is applied to electronic equipment and specifically obtains the real-time voltage value of any phase of the grid to be tested; performs waveform fitting based on the real-time voltage value to obtain the fitted voltage value of any phase; performs a difference operation on the real-time voltage value and the fitted voltage value to obtain the real-time difference between the real-time voltage value and the fitted voltage value; constructs a critical range of normal voltage of any phase based on the real-time difference; monitors the real-time difference based on the critical range, and when the difference exceeds the critical range, determines that a voltage sag has occurred in the grid to be tested. By effectively detecting the occurrence of voltage sag, the dynamic voltage restorer can quickly cut off the grid when a voltage sag occurs.

[0087] The units involved in the embodiments described in this disclosure may be implemented in software or hardware. In some cases, the name of a unit does not limit the unit itself. For example, the first acquisition unit may also be described as a "unit for acquiring at least two Internet Protocol addresses."

[0088] The functions described above herein may be performed, at least in part, by one or more hardware logic components. For example, and without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0089] Example 3

[0090] Figure 5 This is a block diagram of an electronic device according to an embodiment of the present application.

[0091] refer to Figure 5 , which shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present disclosure. The terminal devices in the embodiments of the present disclosure may include, but are not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (such as in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 5 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present disclosure.

[0092] The electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to programs stored in a read-only memory (ROM) 602 or programs loaded from a storage device 606 into a random access memory (RAM) 603. Various programs and data required for the operation of the electronic device 600 are also stored in the RAM 603. The processing device 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0093] Typically, the following devices may be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 608 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 609. The communication device 609 may allow the electronic device 600 to communicate with other devices wirelessly or by wire to exchange data. Figure 5 The electronic device is shown with various devices, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.

[0094] Example 4

[0095] This embodiment provides a computer-readable storage medium that carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device obtains the real-time voltage value of any phase of the power grid to be tested; performs waveform fitting based on the real-time voltage value to obtain the fitted voltage value of any phase; performs a difference operation on the real-time voltage value and the fitted voltage value to obtain a real-time difference between the real-time voltage value and the fitted voltage value; constructs a critical range of normal voltage of any phase based on the real-time difference; monitors the real-time difference based on the critical range, and determines that a voltage sag has occurred in the power grid to be tested when the difference exceeds the critical range. By effectively detecting the occurrence of a voltage sag, the dynamic voltage restorer can quickly disconnect the power grid when a voltage sag occurs.

[0096] It should be noted that the computer-readable medium described above in the present disclosure may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. Computer-readable storage media may include, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wire, optical cable, RF (radio frequency), or any suitable combination thereof.

[0097] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0098] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0099] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0100] The technical solution provided by the present invention is introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for detecting grid voltage sag, applied to electronic equipment, characterized in that: The detection method comprises the steps of: Obtain the real-time voltage value of any phase of the power grid to be tested; Performing waveform fitting according to the real-time voltage value to obtain a fitting voltage value of any phase; performing a difference operation on the real-time voltage value and the fitted voltage value to obtain a real-time difference between the real-time voltage value and the fitted voltage value; Establishing a critical range of a normal voltage of any phase according to the real-time difference; The real-time difference is monitored based on the critical range, and when the difference exceeds the critical range, it is determined that a voltage sag occurs in the power grid to be measured.

2. The detection method according to claim 1, wherein The waveform fitting is performed according to the real-time voltage value to obtain the fitted voltage value of any phase, comprising the steps of: Detecting a phase-locked angle of the real-time voltage value; Calculating the effective value of the real-time voltage value; A waveform fitting is performed according to the phase-locked angle and the effective value to obtain the fitted voltage value.

3. The detection method according to claim 2, wherein In the process of calculating the effective value, a sliding window filtering process is performed on the real-time voltage value.

4. The detection method according to claim 1, wherein The method of monitoring the real-time difference based on the critical range and determining that a voltage sag occurs in the power grid to be measured when the real-time difference exceeds the critical range comprises the following steps: monitoring the difference based on the critical range, and when the real-time difference exceeds the critical range, monitoring a continuous duration of the real-time difference exceeding the critical range; When the continuous duration reaches a preset duration threshold, it is determined that a voltage sag occurs in the power grid to be measured.

5. A detection device for grid voltage sag, applied to electronic equipment, characterized in that: The detection device comprises: A voltage value acquisition module is configured to obtain a real-time voltage value of any phase of the power grid to be tested; a waveform fitting module, configured to perform waveform fitting according to the real-time voltage value to obtain a fitting voltage value of any phase; a difference calculation module, configured to perform a difference operation on the real-time voltage value and the fitted voltage value to obtain a real-time difference between the real-time voltage value and the fitted voltage value; a range building module configured to build a critical range of the normal voltage of any phase according to the real-time difference; The detection execution module is configured to monitor the real-time difference based on the critical range, and determine that a voltage sag occurs in the power grid to be tested when the real-time difference exceeds the critical range.

6. The detection device according to claim 5, characterized in that The waveform fitting module includes: a phase-lock angle detection unit, configured to detect a phase-lock angle of the real-time voltage value; an effective value calculation unit, configured to calculate an effective value of the real-time voltage value; The fitting execution unit is configured to perform waveform fitting according to the phase-locked angle and the effective value to obtain the fitting voltage value.

7. The detection device according to claim 6, characterized in that The effective value calculation unit performs sliding window filtering on the real-time voltage value during the process of calculating the effective value.

8. The detection device according to claim 5, wherein: The detection execution module includes: a difference monitoring unit configured to monitor the real-time difference based on the critical range, and when the real-time difference exceeds the critical range, monitor a continuous duration of the real-time difference exceeding the critical range; The judgment execution unit is configured to determine that a voltage sag occurs in the power grid to be measured when the continuous duration reaches a preset duration threshold.

9. An electronic device, used in a dynamic voltage restorer, characterized in that: The electronic device comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs or instructions; The processor is used to execute the computer program or instruction so that the electronic device implements the method for detecting a grid voltage sag according to any one of claims 1 to 4.

10. A storage medium, applied to an electronic device, characterized in that: The storage medium carries one or more computer programs. When the electronic device executes the one or more computer programs, the electronic device can implement the method for detecting a grid voltage sag as described in any one of claims 1 to 4.

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