A hierarchical overvoltage protection method for converters in three-phase AC power grids

Abstract

The present application discloses a method for layered overvoltage protection of a converter suitable for a three-phase AC power grid, the method comprising: connecting a target filter between the converter input end and a relay board, the target filter comprising a first-stage differential-mode filter and a two-stage common-mode filter to form a first-layer overvoltage protection, wherein the first-stage differential-mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the passing three-phase AC power grid by half; using an external auxiliary source board to control the disconnection of the relay board, the relay board being connected to a main power module to form a second-layer overvoltage protection; setting a multi-stage overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the multi-stage protection threshold comprising an instantaneous overvoltage value and an effective value overvoltage value to form a third-layer overvoltage protection; triggering and starting one of the first-layer overvoltage protection, the second-layer overvoltage protection and the third-layer protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

Description

Technical Field

[0001] The present application relates to the technical field of electrical equipment, and more specifically, to a layered overvoltage protection method for a converter applicable to a three-phase AC power grid. Background Art

[0002] A converter is a power electronic device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of a power system. It is widely used in power transmission and distribution systems, new energy power plants, industrial production, transportation, and other fields.

[0003] Inverter layered overvoltage protection refers to the implementation of multi-stage or process-based overvoltage protection measures within the inverter, designed to ensure effective protection of the equipment at different voltage levels. A common approach involves setting multiple protection thresholds based on the inverter's voltage tolerance. When the voltage exceeds a certain threshold, the corresponding protective measures, such as voltage reduction or power disconnection, are triggered. Overvoltage protection devices, such as lightning arresters, varistors, and surge protectors, are also employed. These devices can respond quickly to abnormal voltage increases, limiting overvoltage to a safe range.

[0004] However, these all have their own shortcomings. For example, when encountering transient grid overvoltage, lightning arresters rely on their own performance to withstand it, and when the multi-level protection threshold encounters excessively high transient voltage, it cannot guarantee that the main power circuit components will not be damaged. Summary of the Invention

[0005] In response to at least one defect or improvement need in the prior art, the present invention provides a layered overvoltage protection method for converters suitable for three-phase AC power grids, which solves the problem that main power circuit components may be damaged when encountering excessively high transient voltages. A suitable filter is added to the input end of the converter to suppress microsecond-level overvoltage surges at the input end; at the same time, an external auxiliary source and a relay board separate the main power and auxiliary power supplies, and the power supply to the main power module can be cut off when overvoltage occurs, thereby achieving the effect of overvoltage fault isolation; and different overvoltage protection thresholds are set in the main power module to realize self-recoverable overvoltage protection with different thresholds.

[0006] To achieve the above-mentioned objectives, according to a first aspect of the present invention, a method for layered overvoltage protection of a converter suitable for a three-phase AC power grid is provided, the method comprising: connecting a target filter between the converter input and a relay board, the target filter comprising a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the passing three-phase AC power grid by half; using an external auxiliary source board to control the disconnection of the relay board, the relay board being connected to a main power module to form a second layer of overvoltage protection; setting a multi-stage overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the multi-stage protection threshold comprising an instantaneous overvoltage value and an effective value overvoltage value to form a third layer of overvoltage protection; triggering and starting one of the first layer of overvoltage protection, the second layer of overvoltage protection, and the third layer of protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0007] In an exemplary embodiment, an external auxiliary source board is used to control the opening and closing of the relay board, and the relay board is connected to the main power module to form a second layer of overvoltage protection, including: the three-phase AC power grid enters the auxiliary source board after passing through the target filter, and generates low-voltage DC power after rectification to control the relay board to open and control the AC input of the main power module; in the event of a transient overvoltage in the three-phase AC power grid, the auxiliary source board is controlled to power off, the relay board is cut off, and the AC input of the main power module is disconnected.

[0008] In an exemplary embodiment, the multi-level overvoltage protection threshold of the main power module is set according to the operating data of the three-phase AC power grid, and the multi-level protection threshold includes an instantaneous overvoltage value and an effective value overvoltage value. Forming a third layer of overvoltage protection includes: setting the first protection threshold, the second protection threshold and the third protection threshold in the multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid; converting the instantaneous overvoltage value of the input voltage of the three-phase AC power grid obtained by sampling the operating data of the three-phase AC power grid from a three-phase stationary abc coordinate system to a two-phase rotating dq coordinate system; and determining the d-axis component of the two-phase rotating dq coordinate system as the instantaneous value of the input voltage.

[0009] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the method further includes: triggering the first layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the first protection threshold and the duration is less than the response time of the auxiliary source board; triggering the second layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the third protection threshold, less than the second protection threshold and the duration is not less than the response time of the auxiliary source board.

[0010] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the method further includes: when the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold, and the duration is not less than T / k seconds, starting the third level of overvoltage protection, where T is the period of the three-phase AC power grid, and k is a positive integer; when the input voltage of the three-phase AC power grid is greater than the effective value overvoltage value, less than the instantaneous overvoltage value, and the duration is not less than n*T seconds, starting the third level of overvoltage protection, where T is the period of the three-phase AC power grid, and n is a positive integer.

[0011] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the method further includes: when it is detected that the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the instantaneous overvoltage value and the duration is greater than n*T seconds; or when it is detected that the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold and the duration is greater than T / k seconds, the alarm is issued and the system enters a fault state shutdown and self-recovery restart, wherein T is the period of the three-phase AC power grid, and n and k are positive integers.

[0012] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, the method further includes: when it is detected that the input voltage of the three-phase AC power grid is less than the effective overvoltage value and the duration is greater than a preset time, starting self-recovery restart.

[0013] According to a second aspect of the present invention, there is also provided a converter layered overvoltage protection device suitable for a three-phase AC power grid, comprising: a first protection unit for connecting a target filter between the converter input and a relay board, the target filter comprising a first-stage differential-mode filter and a two-stage common-mode filter, forming a first layer of overvoltage protection, wherein the first-stage differential-mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the passing three-phase AC power grid by half; a second protection unit for controlling the disconnection of the relay board using an external auxiliary source board, the relay board being connected to a main power module, forming a second layer of overvoltage protection; a third protection unit for setting a multi-stage overvoltage protection threshold of the main power module according to operating data of the three-phase AC power grid, the multi-stage protection threshold comprising an instantaneous overvoltage value and an effective overvoltage value, forming a third layer of overvoltage protection; and a starting protection unit for triggering the start of one of the first layer of overvoltage protection, the second layer of overvoltage protection, and the third layer of protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0014] According to a third aspect of the present invention, a computer-readable storage medium is also provided, in which a computer program is stored, wherein the computer program is configured to execute the above-mentioned converter layered overvoltage protection method applicable to a three-phase AC power grid when running.

[0015] According to a fourth aspect of the present invention, an electronic device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the above-mentioned method for hierarchical overvoltage protection of a converter applicable to a three-phase AC power grid through the computer program.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0017] (1) The present invention provides a method for layered overvoltage protection of a converter suitable for a three-phase AC power grid. A suitable filter is added to the converter input end. The microsecond-level instantaneous high voltage of the power grid is filtered by the filter through the differential mode, and the voltage peak is reduced to half of the original value. An external auxiliary source board and relay board that are easily replaced are provided. When the power grid experiences a transient overvoltage, the auxiliary source board will first be powered off, thereby disconnecting the relay board and disconnecting the AC input of the main power module, thereby protecting the main power module from the impact of the transient overvoltage of the power grid. Even if the power grid experiences a transient overvoltage, only the easily replaceable auxiliary source board will be damaged, thereby improving the maintainability of the entire converter.

[0018] (2) Since the present invention is provided with instantaneous overvoltage protection and effective value overvoltage protection, the instantaneous overvoltage protection adopts the d-axis component Ud of the dq coordinate system to perform instantaneous overvoltage protection, thereby improving the timeliness of the overvoltage protection of the main power module, and the effective value overvoltage protection adopts the average value of multiple cycles to avoid the instantaneous input voltage not reaching the instantaneous overvoltage protection value but exceeding the effective value overvoltage protection value, frequently triggering the overvoltage protection, affecting the stable operation of the converter, thereby improving the stable operation capability of the main power module facing the fluctuating power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. 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 creative work.

[0020] Figure 1 A schematic flow chart of an optional method for hierarchical overvoltage protection of a converter applicable to a three-phase AC power grid provided in an embodiment of the present application;

[0021] Figure 2 A block diagram of an optional layered overvoltage protection structure provided in an embodiment of the present application;

[0022] Figure 3 An optional overall effect diagram of layered overpressure provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of an optional simulation model of the overvoltage suppression effect of a π-shaped filter provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of an optional input overvoltage alarm signal reporting method provided in an embodiment of the present application;

[0025] Figure 6 An optional input overvoltage alarm software flow chart provided in an embodiment of the present application;

[0026] Figure 7 A schematic structural diagram of an optional converter layered overvoltage protection device applicable to a three-phase AC power grid provided in an embodiment of the present application;

[0027] Figure 8 A schematic structural diagram of an optional electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0029] The terms "first," "second," "third," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0030] According to one aspect of the embodiment of the present application, a method for protecting a three-phase AC power grid from overvoltage is provided. Figure 1 The present invention provides a method for protecting a three-phase AC power grid from overvoltage in a converter layered manner.

[0031] Figure 1 FIG. 1 is a flow chart of an optional method for layered overvoltage protection of a converter applicable to a three-phase AC power grid provided in an embodiment of the present application. Figure 1 As shown, the process of the method may include the following steps:

[0032] S102, connecting a target filter between the converter input and the relay board, wherein the target filter includes a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid passing through by half;

[0033] S104, using an external auxiliary source board to control the disconnection of the relay board, the relay board is connected to the main power module to form a second layer of overvoltage protection;

[0034] S106, setting a multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, wherein the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, forming a third layer of overvoltage protection;

[0035] S108 : Triggering and starting one of the first layer overvoltage protection, the second layer overvoltage protection, and the third layer overvoltage protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0036] The converter layered overvoltage protection method for a three-phase AC power grid provided in the present application can be applied to scenarios where layered overvoltage protection is implemented for the entire converter.

[0037] For example, Figure 2 An optional hierarchical overvoltage protection structure block diagram provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the layered overvoltage protection structure mainly includes four parts: the first part is the filter, the second part is the auxiliary source board, the third part is the relay board, and the fourth part is the main power board. The layered overvoltage protection method proposed in this application includes: I layer overvoltage protection (first layer overvoltage protection): target filter (i.e. Figure 2 The filter shown in the figure is used as the first-level overvoltage protection, which reduces the input voltage peak from the input source, uses the target filter to filter out the high-frequency interference generated when the converter is working, and suppresses the microsecond-level overvoltage surge at the input end, thereby reducing the input voltage peak; the second-level overvoltage protection is to use a separate auxiliary source board to control the external relay (i.e. Figure 2 When encountering external high voltage, the auxiliary power supply is cut off first, and then the relay is turned off to protect the main power module (i.e. Figure 2 The auxiliary power board and relay board serve as Layer II overvoltage protection. When the grid overvoltage occurs, the auxiliary power board first shuts off due to overvoltage protection, then disconnects the relay board, cutting off the input to the main power module and protecting it. Layer III overvoltage protection (the third layer of overvoltage protection): The main power module uses multiple protection thresholds, which are based on the RMS overvoltage or transient overvoltage of the input voltage. The transient and RMS overvoltage protection within the main power module serve as Layer III overvoltage protection, preventing grid overvoltage from damaging the main power module components.

[0038] Optionally, an appropriate filter is added to the converter input in this embodiment. The filter comprises a single differential-mode filter and two common-mode filters. Transient overvoltages occur as differential-mode interference. To address this, in the differential-mode filter circuit, a composite magnetic core is used for the differential-mode inductor L, specifically suppressing voltage interference within the 2 kHz to 1 MHz frequency band, which is associated with transient pulse interference.

[0039] Furthermore, a multi-level overvoltage protection threshold of the main power module is set according to the operating data of the three-phase AC power grid. Here, the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, and then the specific overvoltage protection type is determined according to the input voltage and duration of the three-phase AC power grid to perform overvoltage protection.

[0040] Through the above steps S102 to S108, a target filter is connected between the input end of the converter and the relay board, and the target filter includes a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid passing through by half; an external auxiliary source board is used to control the disconnection of the relay board, and the relay board is connected to the main power module to form a second layer of overvoltage protection; a multi-stage overvoltage protection threshold of the main power module is set according to the operating data of the three-phase AC power grid, and the multi-stage protection threshold includes an instantaneous overvoltage value and an effective value overvoltage value to form a third Layer overvoltage protection; triggering the start of the first layer overvoltage protection, the second layer overvoltage protection and one of the third layer overvoltage protection according to the input voltage and duration of the three-phase AC power grid to perform overvoltage protection, which solves the problem that the main power circuit components may be damaged when encountering excessively high transient voltages, and adds a suitable filter at the input end of the converter to suppress the microsecond-level overvoltage surge at the input end; at the same time, the external auxiliary source and the relay board separate the main power and the auxiliary power supply, and the power supply to the main power module can be cut off in the event of overvoltage, thereby achieving the effect of overvoltage fault isolation; and setting different overvoltage protection thresholds in the main power module to realize self-recoverable overvoltage protection with different thresholds.

[0041] In an exemplary embodiment, the use of an external auxiliary source board to control the disconnection of the relay board, wherein the relay board is connected to the main power module to form a second layer of overvoltage protection, includes:

[0042] S11, the three-phase AC grid passes through the target filter and enters the auxiliary source board, where it is rectified to generate low-voltage DC power to control the relay board to open and control the AC input of the main power module;

[0043] S12, in the case of a transient overvoltage in the three-phase AC power grid, controlling the auxiliary source board to power off, disconnecting the relay board, and disconnecting the AC input of the main power module.

[0044] In this embodiment, if Figure 2 As shown, the auxiliary power source is externally located in the converter for easy replacement, and a relay board is added. The three-phase AC grid passes through a filter and enters the auxiliary power source board. After rectification, the low-voltage DC power generated controls the relay board, thereby controlling the AC input to the main power module.

[0045] Through this embodiment, from the perspective of the component structure of the converter, the auxiliary source board and the relay board play the role of isolating the input overvoltage from the main power module. When a transient overvoltage occurs in the power grid, the auxiliary source board first performs overvoltage protection, disconnects the relay board, and cuts off the input of the main power module, preventing the main power module components from being damaged by overvoltage.

[0046] In an exemplary embodiment, the multi-level overvoltage protection threshold of the main power module is set according to the operating data of the three-phase AC power grid, and the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, and forming a third layer of overvoltage protection includes:

[0047] S21, setting a first protection threshold, a second protection threshold, and a third protection threshold among the multi-level overvoltage protection thresholds of the main power module according to operation data of the three-phase AC power grid;

[0048] S22, converting the instantaneous overvoltage value of the input voltage of the three-phase AC power grid obtained by sampling the operating data of the three-phase AC power grid from the three-phase stationary abc coordinate system to the two-phase rotating dq coordinate system;

[0049] S23 , determining the d-axis component of the two-phase rotating dq coordinate system as the instantaneous value of the input voltage.

[0050] In this embodiment, if Figure 3 As shown, the first protection threshold (Va), the second protection threshold (Vb), and the third protection threshold (Vc) of the multi-level overvoltage protection threshold of the main power module are set according to the operating data of the three-phase AC power grid.

[0051] For example, the main power module is designed with multiple overvoltage protection points for instantaneous overvoltage (Vd) and effective overvoltage (Ve). The instantaneous overvoltage protection converts the sampled three-phase input voltage from the three-phase stationary abc coordinate system to the two-phase rotating dq coordinate system. The d-axis component Ud is the instantaneous input voltage value, and this is used for instantaneous input overvoltage protection. Effective overvoltage protection uses an average value over multiple cycles, with the relationship between the two being Vd > Ve.

[0052] Through this embodiment, instantaneous overvoltage protection and effective value overvoltage protection are provided. The instantaneous overvoltage protection adopts the d-axis component Ud of the dq coordinate system to perform instantaneous overvoltage protection, thereby improving the timeliness of the overvoltage protection of the main power module. The effective value overvoltage protection adopts the average value of multiple cycles to avoid the situation where the instantaneous input voltage does not reach the instantaneous overvoltage protection value but exceeds the effective value overvoltage protection value, frequently triggering the overvoltage protection, affecting the stable operation of the converter, and improving the stable operation capability of the main power module in the face of fluctuating power grids.

[0053] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes:

[0054] S31, triggering the first layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the first protection threshold, and the duration is less than the response time of the auxiliary source board;

[0055] S32. When the input voltage of the three-phase AC power grid is greater than the third protection threshold, less than the second protection threshold, and the duration is not less than the response time of the auxiliary source board, trigger the second-layer overvoltage protection.

[0056] In this embodiment, as Figure 3 shown, for the overall effect of the converter hierarchical overvoltage protection, the input voltage V satisfies Ve < V < Va, that is, greater than the effective value overvoltage value, less than the first protection threshold, and the duration is less than T1 seconds. The first-layer overvoltage protection is triggered to reduce the input voltage peak value and protect the devices at the back end of the filter. The input voltage V satisfies Vc < V < Vb, that is, greater than the third protection threshold, less than the second protection threshold, and the action time is not less than T1 seconds. T1 is the response time of the auxiliary source board module. The second-layer overvoltage protection is triggered, which can cut off the auxiliary source power supply, thereby cutting off the AC input of the main power module and protecting the main power module.

[0057] As Figure 4 shown, from the aspect of converter overvoltage suppression, the differential-mode filtering part of the filter can reduce the peak value of different microsecond-level power grid overvoltage signals by half. The interference source is Figure 4 V1 in, U1 is the switching power supply, and the line-to-line differential-mode inductor is equivalent to Figure 4 the inductor L2 in; the high-frequency resistance of the inductor L2 under pulsed high current is set to 2 ohms. The line-to-line differential-mode capacitor is simulated by the resistor R1, and the line-to-line metal oxide varistor (Metal-Oxide Varistor, MOV) is simulated by the capacitor C1 + resistor R7 and the capacitor C4 + resistor R8. The equivalent model under high-frequency pulse conditions is the switching power supply U2 + resistor R4 or the switching power supply U3 + resistor R5. The equivalent input impedance of the ACDC (AC-DC conversion) is the resistor R3. In addition, the simulation experiment shows that in the double exponential pulse waveform, the first curve is a double exponential voltage signal with a peak value of 410V and a pulse width of 120uS, and the second curve is the voltage signal applied to the load end after attenuation by the filter circuit, with an actual peak value of about 200V and an attenuation amount close to half. In the square wave pulse waveform, the first curve is a square wave interference voltage signal with a peak value of 410V and a pulse width of 120uS, and the second curve is the voltage signal applied to the load end after attenuation by the filter circuit, with an actual peak value of about 230V and an attenuation amount close to 45%.

[0058] Through this embodiment, from the aspect of converter overvoltage suppression, the differential-mode filtering part of the filter can reduce the peak value of different power grid overvoltage signals within microseconds by half. From the perspective of the converter structure composition, the fault point caused by the power grid overvoltage is transferred to the auxiliary source board that is easy to replace, improving the maintainability of the entire converter. From the perspective of the timeliness of the converter main power module, instantaneous overvoltage protection is added on the basis of the traditional effective value overvoltage protection, and its protection time for instantaneous high voltage is greatly shortened.

[0059] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes:

[0060] S41, when the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold, and the duration is not less than T / k seconds, start the third-layer overvoltage protection, where T is the period of the three-phase AC power grid and k is a positive integer;

[0061] S42, when the input voltage of the three-phase AC power grid is greater than the effective value overvoltage value, less than the instantaneous overvoltage value, and the duration is not less than n*T seconds, start the third-layer overvoltage protection, where T is the period of the three-phase AC power grid and n is a positive integer.

[0062] In this embodiment, the input voltage V satisfies Vd < V < Vc, that is, greater than the instantaneous overvoltage value, less than the third protection threshold, and the action time is not less than T / k seconds. The instantaneous overvoltage protection of the third-layer overvoltage protection is started, and the drive of the main power module can be turned off to protect the related devices of the main power module. The input voltage V satisfies Ve < V < Vd, that is, greater than the effective value overvoltage value, less than the instantaneous overvoltage value, and the action time is not less than n*T seconds. The effective value overvoltage protection of the third-layer overvoltage protection is started, and the drive of the main power module can be turned off to protect the related devices of the main power module. Here, n is an integer value, n ≥ 1, and k is an integer value, generally taking 2 to 6.

[0063] Through this embodiment, from the perspective of the timeliness of the main power module of the converter, the response time of the instantaneous overvoltage protection is greatly shortened compared with the traditional overvoltage protection time. In order to generate input overvoltage protection within a time less than one switching period of the input voltage fluctuation, the instantaneous values of the three-phase input voltage obtained by sampling are converted from the three-phase stationary abc coordinate system to the two-phase rotating dq coordinate system, and the d-axis component Ud is the instantaneous value of the input voltage, and Ud is used for instantaneous input overvoltage protection.

[0064] In an exemplary embodiment, after setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes:

[0065] S51, when it is detected that the input voltage of the three-phase AC power grid is greater than the effective value overvoltage value, less than the instantaneous overvoltage value, and the duration is greater than n*T seconds; or,

[0066] S52. When it is detected that the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold, and the duration is greater than T / k seconds, after alarming, it enters the fault state and shuts down, and restarts automatically. Here, T is the period of the three-phase AC power grid, and n and k are positive integers.

[0067] In this embodiment, in combination with Figure 5 and Figure 6 As shown, using the AC / DC high-voltage power module 1 (AC-DC conversion high-voltage power module 1) and the AC / DC high-voltage power module 2 (AC-DC conversion high-voltage power module), the internal input overvoltage alarm reporting process of the main power module. The input voltage inside the main power module first passes through Hall voltage sampling and operational amplifier processing, and then enters the rectifier control board. If "AC input overvoltage" is triggered after calculation, the alarm is generated by the rectifier control board, transmitted to the conversion board control board through inter-board communication, then transmitted to the communication control board through the internal CAN (internal controller area network), and finally reported to the backend through the external CAN (external controller area network).

[0068] It should be noted that the sampling ratio of Hall voltage sampling can be 2.5:1. UA, UB, and UC are phase voltages. Specifically, UA is the voltage of phase A relative to the neutral point, UB is the voltage of phase B relative to the neutral point, and UC is the voltage of phase C relative to the neutral point; UAB, UBC, and UCA are line voltages between the three phases. Specifically, UAB is the voltage between phase A and phase B, UBC is the voltage between phase B and phase C, and UCA is the voltage between phase C and phase A.

[0069] When it is detected that the input voltage V satisfies Ve < V < Vd (that is, greater than the effective value overvoltage value and less than the instantaneous overvoltage value) and the duration is greater than n*T seconds, or the input voltage V satisfies Vd < V < Vc (that is, greater than the instantaneous overvoltage value and less than the third protection threshold) and the duration is greater than T / k seconds, an alarm of "AC input overvoltage" is given, it enters the fault state and shuts down, and the fault light is on, and it can be self-recovered. Here, T is the period of the AC power grid, n is an integer value, n ≥ 1, and k is an integer value, generally taking 2 to 6.

[0070] Through this embodiment, from the perspective of the stable operation ability in the face of a fluctuating power grid, the effective value overvoltage protection takes the average value of the input voltage over multiple switching cycles. In this way, when the input voltage Ve < V < Vd but the duration does not exceed n*T seconds, the input overvoltage alarm will not be triggered, thereby improving the stability of the converter in the face of a fluctuating power grid. <​​​

[0072] S61 , when it is detected that the input voltage of the three-phase AC power grid is less than the effective overvoltage value and the duration is greater than a preset time, start self-recovery restart.

[0073] In this embodiment, when it is detected that the input voltage is less than Ve and the duration is greater than a preset time, for example, 10 seconds, the system will automatically recover and restart.

[0074] In this embodiment, when the third level of overvoltage protection is enabled, the specific software process is to detect the input voltage. If the input voltage is detected to be less than the effective overvoltage value and the duration is greater than 10 seconds, self-recovery and restart can be initiated. The effective overvoltage protection uses an average value over multiple cycles to avoid frequent overvoltage protection triggering when the instantaneous input voltage does not reach the instantaneous overvoltage protection value but exceeds the effective overvoltage protection value, which affects the stable operation of the converter. This improves the stable operation of the main power module in the face of fluctuating power grids.

[0075] According to another aspect of the embodiments of the present application, an overvoltage protection device for implementing the above-mentioned converter layered overvoltage protection method applicable to a three-phase AC power grid is also provided. Figure 7 FIG is a schematic structural diagram of an optional converter layered overvoltage protection device applicable to a three-phase AC power grid according to an embodiment of the present application. Figure 7 As shown, the device may include:

[0076] A first protection unit 702 is configured to connect a target filter between the converter input and the relay board. The target filter includes a first stage of differential mode filtering and two stages of common mode filtering, forming a first layer of overvoltage protection. The first stage of differential mode filtering in the target filter is configured to reduce the peak value of the instantaneous high voltage of the passing three-phase AC power grid by half.

[0077] The second protection unit 704 is used to control the disconnection of the relay board using an external auxiliary source board. The relay board is connected to the main power module to form a second layer of overvoltage protection;

[0078] A third protection unit 706 is configured to set a multi-level overvoltage protection threshold for the main power module according to the operating data of the three-phase AC power grid, wherein the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, forming a third layer of overvoltage protection;

[0079] The protection starting unit 708 is configured to trigger starting one of the first layer overvoltage protection, the second layer overvoltage protection, and the third layer overvoltage protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0080] It should be noted that the first protection unit 702 in this embodiment can be used to execute the above step S102, the second protection unit 704 in this embodiment can be used to execute the above step S104, the third protection unit 706 in this embodiment can be used to execute the above step S106, and the startup protection unit 708 in this embodiment can be used to execute the above step S108.

[0081] Through the above-mentioned module, by connecting the target filter between the input end of the converter and the relay board, the target filter includes a first-stage differential mode filter and a two-stage common mode filter, forming a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid passing through by half; an external auxiliary source board is used to control the disconnection of the relay board, and the relay board is connected to the main power module to form a second layer of overvoltage protection; the multi-stage overvoltage protection threshold of the main power module is set according to the operating data of the three-phase AC power grid, and the multi-stage protection threshold includes an instantaneous overvoltage value and an effective value overvoltage value, forming a third layer of overvoltage protection ; According to the input voltage and duration of the three-phase AC power grid, the first layer of overvoltage protection, the second layer of overvoltage protection and one of the third layer of protection are triggered to start overvoltage protection, which solves the problem that the main power circuit components may be damaged when encountering excessively high transient voltages. A suitable filter is added to the input end of the converter to suppress the microsecond-level overvoltage surge at the input end; at the same time, the external auxiliary source and the relay board separate the main power and the auxiliary power supply, and the power supply to the main power module can be cut off in the event of overvoltage, thereby achieving the effect of overvoltage fault isolation; and different overvoltage protection thresholds are set in the main power module to achieve self-recoverable overvoltage protection with different thresholds.

[0082] In an exemplary embodiment, the second protection unit includes:

[0083] A first control module is used to control the AC input of the main power module by controlling the three-phase AC power grid to enter the auxiliary source board after passing through the target filter and generate low-voltage DC power after rectification;

[0084] The second control module is used to control the auxiliary source board to power off, cut off the relay board, and disconnect the AC input of the main power module when the three-phase AC power grid is instantaneously overvoltage.

[0085] In an exemplary embodiment, the third protection unit includes:

[0086] A setting module, configured to set a first protection threshold, a second protection threshold, and a third protection threshold among the multi-level overvoltage protection thresholds of the main power module according to operation data of the three-phase AC power grid;

[0087] A conversion module, configured to convert an instantaneous overvoltage value of the input voltage of the three-phase AC power grid obtained by sampling the operating data of the three-phase AC power grid from a three-phase stationary abc coordinate system to a two-phase rotating dq coordinate system;

[0088] A determination module is used to determine the d-axis component of the two-phase rotating dq coordinate system as the instantaneous value of the input voltage.

[0089] In an exemplary embodiment, the apparatus further comprises:

[0090] a first starting unit, configured to trigger the first layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than an effective overvoltage value, less than the first protection threshold, and the duration is less than the response time of the auxiliary source board;

[0091] The second starting unit is used to trigger the second layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the third protection threshold, less than the second protection threshold and the duration is not less than the response time of the auxiliary source board.

[0092] In an exemplary embodiment, the apparatus further comprises:

[0093] a third starting unit, configured to start the third level of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value and less than the third protection threshold and the duration is not less than T / k seconds, where T is the period of the three-phase AC power grid and k is a positive integer;

[0094] The fourth starting unit is used to start the third layer of overvoltage protection when the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the instantaneous overvoltage value and the duration is not less than n*T seconds, where T is the period of the three-phase AC power grid and n is a positive integer.

[0095] In an exemplary embodiment, the apparatus further comprises:

[0096] an alarm unit, configured to, when detecting that the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the instantaneous overvoltage value, and lasts for more than n*T seconds; or

[0097] When it is detected that the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold and the duration is greater than T / k seconds, the system will enter a fault state and shut down after an alarm, and then self-recover and restart, where T is the period of the three-phase AC power grid, and n and k are positive integers.

[0098] In an exemplary embodiment, the apparatus further comprises:

[0099] The restart unit is used to start self-recovery restart when it is detected that the input voltage of the three-phase AC power grid is less than the effective overvoltage value and the duration is greater than a preset time.

[0100] It should be noted here that the examples and scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the contents disclosed in the above embodiments. It should be noted that the above modules as part of the device can run in a hardware environment, can be implemented by software, and can also be implemented by hardware, where the hardware environment includes a network environment.

[0101] According to another aspect of the embodiments of the present application, a storage medium is further provided. Optionally, in this embodiment, the storage medium can be used to execute the program code of any of the above-mentioned methods for layered overvoltage protection of a three-phase AC power grid converter in the embodiments of the present application.

[0102] Optionally, in this embodiment, the storage medium is configured to store program codes for executing the following steps:

[0103] S1, connecting a target filter between the converter input and the relay board, the target filter including a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid by half;

[0104] S2, using an external auxiliary source board to control the disconnection of the relay board, the relay board is connected to the main power module to form a second layer of overvoltage protection;

[0105] S3, setting a multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, wherein the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, forming a third layer of overvoltage protection;

[0106] S4, triggering and starting one of the first layer overvoltage protection, the second layer overvoltage protection and the third layer overvoltage protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0107] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, which will not be described in detail in this embodiment.

[0108] Among them, computer-readable storage media may include, but are not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0109] According to another aspect of the embodiments of the present application, an electronic device for implementing the above-mentioned converter layered overvoltage protection method applicable to a three-phase AC power grid is also provided. The electronic device may be a server, a terminal, or a combination thereof.

[0110] Figure 8 is a schematic structural diagram of an optional electronic device according to an embodiment of the present application, such as Figure 8 As shown, it includes a processor 802, a communication interface 804, a memory 806 and a communication bus 808, wherein the processor 802, the communication interface 804, and the memory 806 communicate with each other via the communication bus 808, wherein,

[0111] Memory 806, for storing computer programs;

[0112] The processor 802 is configured to execute the computer program stored in the memory 806 to implement the following steps:

[0113] S1, connecting a target filter between the converter input and the relay board, the target filter including a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection, wherein the first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid by half;

[0114] S2, using an external auxiliary source board to control the disconnection of the relay board, the relay board is connected to the main power module to form a second layer of overvoltage protection;

[0115] S3, setting a multi-level overvoltage protection threshold of the main power module according to the operating data of the three-phase AC power grid, wherein the multi-level protection threshold includes an instantaneous overvoltage value and an effective overvoltage value, forming a third layer of overvoltage protection;

[0116] S4, triggering and starting one of the first layer overvoltage protection, the second layer overvoltage protection and the third layer overvoltage protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid.

[0117] Optionally, the communication bus may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 The communication interface is used for communication between the electronic device and other devices.

[0118] The memory may include RAM, or may include non-volatile memory, such as at least one disk memory. Alternatively, the memory may also be at least one storage device located away from the aforementioned processor.

[0119] As an example, the memory 806 may include, but is not limited to, the first protection unit 702, the second protection unit 704, the third protection unit 706, and the startup protection unit 708 of the aforementioned converter layered overvoltage protection device applicable to a three-phase AC power grid. Furthermore, the memory 806 may also include, but is not limited to, other module units of the aforementioned converter layered overvoltage protection device applicable to a three-phase AC power grid, which will not be described in detail in this example.

[0120] The above-mentioned processor can be a general-purpose processor, including but not limited to: CPU (Central Processing Unit), NP (Network Processor), etc.; it can also be DSP (Digital Signal Processing), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0121] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0122] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0123] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interface, and the indirect coupling or communication connection of the device or unit can be electrical or other forms.

[0125] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0127] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk, or optical disk, etc., various media that can store program code.

[0128] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable memory, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0129] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0130] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0131] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for layered overvoltage protection of a converter applicable to a three-phase AC power grid, characterized in that: include: A target filter is connected between the converter input and the relay board. The target filter includes a first-stage differential mode filter and a two-stage common mode filter to form a first layer of overvoltage protection. The first-stage differential mode filter in the target filter is used to reduce the peak value of the instantaneous high voltage of the three-phase AC power grid by half. An external auxiliary source board is used to control the disconnection of the relay board, and the relay board is connected to the main power module to form a second layer of overvoltage protection; Setting a multi-level overvoltage protection threshold of the main power module according to operating data of the three-phase AC power grid to form a third layer of overvoltage protection for controlling the main power module; Overvoltage protection is performed by triggering one of the first layer of overvoltage protection, the second layer of overvoltage protection, and the third layer of overvoltage protection according to the input voltage and duration of the three-phase AC power grid and the multi-level overvoltage protection threshold, wherein the multi-level overvoltage protection threshold includes an instantaneous overvoltage value and an effective value overvoltage value.

2. The method for protecting a converter from overvoltage in a three-phase AC power grid according to claim 1, wherein: The use of an external auxiliary source board to control the disconnection of the relay board, the relay board being connected to the main power module to form a second layer of overvoltage protection includes: The three-phase AC power grid passes through the target filter and enters the auxiliary source board, and after rectification, generates low-voltage DC power to control the relay board to open and control the AC input of the main power module; In the event of a transient overvoltage in the three-phase AC power grid, the auxiliary source board is controlled to be powered off, the relay board is disconnected, and the AC input of the main power module is disconnected.

3. The method for converter layered overvoltage protection applicable to a three-phase AC power grid according to claim 1, characterized in that: The step of setting the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid to form a third level of overvoltage protection for controlling the main power module includes: Setting a first protection threshold, a second protection threshold, and a third protection threshold among the multi-level overvoltage protection thresholds of the main power module according to operation data of the three-phase AC power grid; The instantaneous overvoltage value of the input voltage of the three-phase AC power grid obtained by sampling the operating data of the three-phase AC power grid is converted from the three-phase stationary abc coordinate system to the two-phase rotating dq coordinate system; The d-axis component of the two-phase rotating dq coordinate system is determined as the instantaneous value of the input voltage.

4. The method for protecting a converter from overvoltage in a three-phase AC power grid according to claim 3, wherein: After setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes: When the input voltage of the three-phase AC power grid is greater than the effective overvoltage value, less than the first protection threshold, and the duration is less than the response time of the auxiliary source board, triggering the first layer of overvoltage protection; When the input voltage of the three-phase AC power grid is greater than the third protection threshold, less than the second protection threshold and the duration is not less than the response time of the auxiliary source board, the second layer of overvoltage protection is triggered.

5. The method for protecting a converter from overvoltage in a three-phase AC power grid according to claim 3, wherein: After setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes: When the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value and less than the third protection threshold and the duration is not less than T / k seconds, the third level of overvoltage protection is activated, where T is the period of the three-phase AC power grid and k is a positive integer; When the input voltage of the three-phase AC power grid is greater than the effective overvoltage value and less than the instantaneous overvoltage value and the duration is not less than n*T seconds, the third level of overvoltage protection is activated, where T is the period of the three-phase AC power grid and n is a positive integer.

6. The method for converter layered overvoltage protection applicable to a three-phase AC power grid according to claim 3, characterized in that: After setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes: When it is detected that the input voltage of the three-phase AC power grid is greater than the effective overvoltage value and less than the instantaneous overvoltage value and the duration is greater than n*T seconds; or, When it is detected that the input voltage of the three-phase AC power grid is greater than the instantaneous overvoltage value, less than the third protection threshold and the duration is greater than T / k seconds, the system will enter a fault state and shut down after an alarm, and then self-recover and restart, where T is the period of the three-phase AC power grid, and n and k are positive integers.

7. The method for converter layered overvoltage protection applicable to a three-phase AC power grid according to claim 3, characterized in that: After setting the first protection threshold, the second protection threshold, and the third protection threshold of the multi-level overvoltage protection threshold of the main power module according to the operation data of the three-phase AC power grid, the method further includes: When it is detected that the input voltage of the three-phase AC power grid is less than the effective overvoltage value and the duration is greater than a preset time, self-recovery restart is started.

8. A converter layered overvoltage protection device suitable for a three-phase AC power grid, characterized in that: include: a first protection unit, configured to connect a target filter between the converter input and the relay board, the target filter comprising a first stage of differential mode filtering and a two-stage common mode filtering, forming a first layer of overvoltage protection, wherein the first stage of differential mode filtering in the target filter is configured to reduce the peak value of the instantaneous high voltage of the passing three-phase AC power grid by half; A second protection unit is used to control the disconnection of the relay board using an external auxiliary source board, and the relay board is connected to the main power module to form a second layer of overvoltage protection; a third protection unit, configured to set a multi-level overvoltage protection threshold of the main power module according to operation data of the three-phase AC power grid, thereby forming a third layer of overvoltage protection for controlling the main power module; A starting protection unit is used to trigger the start of one of the first layer of overvoltage protection, the second layer of overvoltage protection, and the third layer of overvoltage protection to perform overvoltage protection according to the input voltage and duration of the three-phase AC power grid and the multi-level overvoltage protection threshold, wherein the multi-level overvoltage protection threshold includes an instantaneous overvoltage value and an effective value overvoltage value.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein the program executes the method according to any one of claims 1 to 7 when executed.

10. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to execute the method according to any one of claims 1 to 7 through the computer program.

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