Voltage anomaly detection method, voltage anomaly detection circuit, and electronic device

Abstract

The application discloses a voltage anomaly detection method, a voltage anomaly detection circuit and electronic equipment. The voltage anomaly detection method comprises the following steps: obtaining three-phase line voltages in a three-phase power supply circuit; performing accumulation operation on the absolute values of the amplitudes of the three-phase line voltages to obtain a reference voltage value; detecting whether a cumulative characteristic parameter of the reference voltage value not located in a set threshold range is less than a set threshold value; if the cumulative characteristic parameter is less than the set threshold value, returning to the step of obtaining the three-phase line voltages in the three-phase power supply circuit; and if the cumulative characteristic parameter is not less than the set threshold value, determining that the three-phase line voltages have voltage anomalies. In the foregoing manner, the voltage anomaly detection method of the application does not need to detect the effective value of the three-phase alternating voltage, has low operation amount, is more rapid in detection, has high accuracy, and is easy to implement in engineering.

Description

Technical Field

[0001] This application relates to the field of voltage detection technology, and in particular to a voltage anomaly detection method, voltage anomaly detection circuit, and electronic equipment. Background Technology

[0002] Three-phase alternating current (AC) is a power system composed of three symmetrical sinusoidal AC currents with the same frequency, equal potential amplitude, and a phase difference of 120°. It is widely used in high-power power supply of 6kW (kilowatts) and above. In practical applications of three-phase AC, especially in server power supplies, medical power supplies, and production line motor drive power supplies, how to quickly identify voltage anomalies, such as power outages, overvoltage, and undervoltage faults, to avoid serious consequences such as data loss in data centers, medical accidents, and the generation of a large number of defective products on production lines, has become one of the hot research topics in this field.

[0003] However, the voltage anomaly detection of three-phase AC power in related technologies usually requires detecting the effective value of the three-phase AC voltage and judging the voltage anomaly based on the effective value of the three-phase voltage. However, the detection of the effective value of the three-phase voltage requires one AC cycle, that is, 20ms (milliseconds), which takes a long time and makes it impossible to respond and restore power supply in time. It may even inevitably cause data loss, damage to circuit components, and other consequences. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a voltage anomaly detection method, voltage anomaly detection circuit, and electronic equipment, which can solve the problem that the voltage anomaly detection in the prior art takes a long time, resulting in the inability to respond and restore power in a timely manner, and even inevitably causing data loss, damage to circuit components, and other consequences.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: providing a voltage anomaly detection method applied in a three-phase power supply circuit, wherein the voltage anomaly detection method includes: acquiring the three-phase line voltages in the three-phase power supply circuit; accumulating the absolute values ​​of the amplitudes of each phase line voltage in the three-phase line voltages to obtain a reference voltage value; detecting whether the cumulative characteristic parameter of the reference voltage value not falling within a set threshold range is less than a set threshold; if the cumulative characteristic parameter is less than the set threshold, returning to the step of acquiring the three-phase line voltages in the three-phase power supply circuit; if the cumulative characteristic parameter is not less than the set threshold, determining that there is a voltage anomaly in the three-phase line voltages.

[0006] The step of detecting whether the cumulative characteristic parameter whose reference voltage value is not within the set threshold range is less than the set threshold includes: detecting whether the reference voltage value is within the set threshold range; if the reference voltage value is not within the set threshold range, detecting whether the cumulative number of abnormalities is less than the set number; if the cumulative number of abnormalities is less than the set number, incrementing the cumulative number of abnormalities by 1, and returning to execute the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the cumulative number of abnormalities is not less than the set number, determining that the three-phase line voltage has an abnormality.

[0007] The voltage anomaly detection method further includes: if the reference voltage value is within the set threshold range, checking whether the cumulative number of anomalies is greater than 0; if the cumulative number of anomalies is greater than 0, decrementing the cumulative number of anomalies by 1 and returning to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the cumulative number of anomalies is equal to 0, determining that the three-phase line voltage is not abnormal, and keeping the cumulative number of anomalies unchanged.

[0008] The step of detecting whether the cumulative characteristic parameter whose reference voltage value is not within the set threshold range is less than the set threshold includes: detecting whether the reference voltage value is less than the power-off threshold; the power-off threshold is a set multiple of the rated peak voltage of the three-phase line voltage, and the set multiple is less than 0.5; if the reference voltage value is less than the power-off threshold, detecting whether the power-off timing value is less than the set time threshold; if the power-off timing value is less than the set time threshold, adding a step value to the power-off timing value, and returning to execute the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the power-off timing value is not less than the set time threshold, determining that there is a power-off abnormality in the three-phase line voltage, and setting the power-off flag to 1.

[0009] The voltage anomaly detection method further includes: if the reference voltage value is not less than the power-off threshold, detecting whether the power-off timing value is greater than the step value; if the power-off timing value is greater than the step value, subtracting the step value from the power-off timing value and returning to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the power-off timing value is not greater than the step value, setting the power-off timing value to 0 and setting the power-off flag to 0.

[0010] The step of detecting whether the cumulative characteristic parameter of the reference voltage value not falling within the set threshold range is less than the set threshold includes: performing band-stop filtering on the reference voltage value to obtain the average reference voltage value; detecting whether the average reference voltage value is less than the undervoltage threshold; the undervoltage threshold is the product of the rated peak voltage of the three-phase line voltage and the undervoltage coefficient, and the undervoltage coefficient is less than... If the average value of the reference voltage is less than the undervoltage threshold, check if the undervoltage timing value is less than the set time threshold. If the undervoltage timing value is less than the set time threshold, add a step value to the undervoltage timing value and return to execute the step of obtaining the three-phase line voltage in the three-phase power supply circuit. If the undervoltage timing value is not less than the set time threshold, determine that there is an undervoltage abnormality in the three-phase line voltage and set the undervoltage flag to 1.

[0011] The voltage anomaly detection method further includes: if the average value of the reference voltage is not less than the undervoltage threshold, detecting whether the undervoltage timing value is greater than the step value; if the undervoltage timing value is greater than the step value, subtracting the step value from the undervoltage timing value and returning to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the undervoltage timing value is not greater than the step value, setting the undervoltage timing value to 0 and setting the undervoltage flag to 0.

[0012] The step of detecting whether the cumulative characteristic parameter of the reference voltage value is not within the set threshold range is less than the set threshold includes: performing band-stop filtering on the reference voltage value to obtain the average reference voltage value; detecting whether the average reference voltage value is greater than the overvoltage threshold; the overvoltage threshold is the product of the rated peak voltage of the three-phase line voltage and the overvoltage coefficient, and the overvoltage coefficient is greater than 2; if the average reference voltage value is greater than the overvoltage threshold, detecting whether the overvoltage timing value is less than the set time threshold; if the overvoltage timing value is less than the set time threshold, adding a step value to the overvoltage timing value and returning to execute the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the overvoltage timing value is not less than the set time threshold, determining that there is an overvoltage anomaly in the three-phase line voltage and setting the overvoltage flag to 1.

[0013] The voltage anomaly detection method further includes: if the average value of the reference voltage is not greater than the overvoltage threshold, detecting whether the overvoltage timing value is greater than the step value; if the overvoltage timing value is greater than the step value, subtracting the step value from the overvoltage timing value and returning to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; if the overvoltage timing value is not greater than the step value, setting the overvoltage timing value to 0 and setting the overvoltage flag to 0.

[0014] The step of obtaining the average reference voltage value by performing band-stop filtering on the reference voltage value includes: sending the reference voltage value to the band-stop filter so that the band-stop filter performs band-stop filtering on the reference voltage value to obtain the average reference voltage value; receiving the average reference voltage value sent by the band-stop filter; or, performing calculation on the reference voltage value using a filtering characteristic function to obtain the average reference voltage value.

[0015] The steps for obtaining the three-phase line voltages in a three-phase power supply circuit include: obtaining the instantaneous three-phase line voltages in the three-phase power supply circuit using a set sampling frequency; the steps for accumulating the absolute values ​​of the amplitudes of each phase line voltage in the three-phase line voltages to obtain a reference voltage value include: accumulating the absolute values ​​of the instantaneous amplitudes of each phase instantaneous line voltage in the three-phase instantaneous line voltages to obtain a reference instantaneous voltage value; and the steps for performing band-stop filtering on the reference voltage value to obtain the average value of the reference voltage include: detecting whether the cumulative number of reference instantaneous voltage values ​​obtained is less than a set number; if the cumulative number of obtained values ​​is less than the set number, incrementing the cumulative number of obtained values ​​by 1 and returning to execute the step of obtaining the three-phase instantaneous line voltages in the three-phase power supply circuit using a set sampling frequency; if the cumulative number of obtained values ​​is not less than the set number, averaging the set number of reference instantaneous voltage values ​​to obtain the average value of the reference voltage.

[0016] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a voltage anomaly detection circuit, wherein the voltage anomaly detection circuit is used to couple with a three-phase power supply circuit; wherein the voltage anomaly detection circuit uses the voltage anomaly detection method as described in any of the above claims to control the three-phase power supply circuit.

[0017] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide an electronic device, wherein the electronic device includes a housing and a voltage abnormality detection circuit connected to the housing; wherein the voltage abnormality detection circuit is the voltage abnormality detection circuit as described above.

[0018] The beneficial effects of this application are as follows: Unlike existing technologies, the voltage anomaly detection method provided in this application acquires the three-phase line voltages in a three-phase power supply circuit, accumulates the absolute values ​​of the amplitudes of each phase line voltage to obtain a reference voltage value, and performs cumulative anomaly detection based on this reference voltage value. This effectively avoids detecting the effective value of the three-phase AC voltage, eliminating the need to complete the detection within one AC cycle. Detection is faster, facilitating rapid response and power restoration to maintain power supply stability and prevent data loss, circuit component damage, and other consequences. Furthermore, it has low computational complexity, high accuracy, and is easy to implement in engineering. The cumulative anomaly detection method also avoids misjudgments due to transient interference, improving robustness. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a flowchart illustrating the first embodiment of the voltage anomaly detection method of this application; Figure 2 This is a schematic diagram of the first embodiment of the voltage anomaly detection circuit and the three-phase power supply circuit of this application; Figure 3 This is a schematic diagram of an embodiment of the three-phase line voltage in a three-phase power supply system with a neutral line; Figure 4 This is a schematic diagram of an embodiment of the three-phase line voltage in a three-phase power supply system without a neutral wire; Figure 5 This is a waveform diagram of an embodiment of symmetrical three-phase line voltage; Figure 6 This is a waveform diagram of an embodiment of the sum of the absolute values ​​of symmetrical three-phase line voltages; Figure 7 This is a flowchart illustrating the second embodiment of the voltage anomaly detection method of this application; Figure 8 This is a flowchart illustrating the third embodiment of the voltage anomaly detection method of this application; Figure 9 This is a flowchart illustrating the fourth embodiment of the voltage anomaly detection method of this application; Figure 10 yes Figure 9 A flowchart illustrating an embodiment of S43; Figure 11 This is a flowchart illustrating the fifth embodiment of the voltage anomaly detection method of this application; Figure 12 This is a flowchart illustrating the sixth embodiment of the voltage anomaly detection method of this application; Figure 13 This is a schematic diagram of one embodiment of the electronic device of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0022] In this document, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that the implementations described herein can be combined with other implementations.

[0023] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Please refer to the following: Figure 1 and Figure 2 ,in, Figure 1 This is a flowchart illustrating the first embodiment of the voltage anomaly detection method of this application. Figure 2 This is a schematic diagram of the first embodiment of the voltage anomaly detection circuit and three-phase power supply circuit of this application. Specifically, it may include the following steps: S11: Obtain the three-phase line voltage in the three-phase power supply circuit.

[0025] It is understood that the voltage anomaly detection method of the three-phase power supply circuit 102 in this embodiment is specifically applied to, for example... Figure 2 In the three-phase power supply circuit 102 shown; wherein, the first voltage anomaly detection circuit 101 is coupled to the three-phase power supply circuit 102 to control the three-phase power supply circuit 102 using any of the voltage anomaly detection methods described herein.

[0026] It is worth noting that the three-phase power supply circuit 102 can specifically be a power supply with three-phase AC power, or a converter circuit that receives three-phase grid power, regulates and converts it, and then supplies power to the load circuit. The grid is a comprehensive power network system connecting power generation, transmission, distribution, and consumption, and its core function is to achieve safe and efficient transmission and dynamic balance control of electrical energy. Three-phase is the most common type of multi-phase AC system, and it is also divided into symmetrical three-phase and asymmetrical three-phase. A symmetrical three-phase power supply consists of three sinusoidal voltage sources with equal amplitude, same frequency, and initial phases differing by 120°, connected in a star (Y) or delta (△) configuration. These three power sources are referred to as phase A, phase B, and phase C, respectively. It has the advantage of facilitating power transmission and is a basic method of power supply and transmission.

[0027] The phase sequence (order) A, B, C of the three-phase voltages mentioned above is called the positive sequence or forward sequence. The opposite is called the reverse sequence or inverse sequence. Power systems generally use the positive sequence.

[0028] The symmetrical three-phase voltage satisfies the condition: ua + ub + uc = 0; Or phasor expression: + + =0; where ua is the phase A voltage. Let ua be the phasor representation of phase A voltage; ub be the phase B voltage. Let ub be the phasor representation of the phase B voltage; uc is the phase C voltage. This is the phasor representation of the C-phase voltage uc.

[0029] A symmetrical three-phase voltage is provided by a three-phase generator. In a three-phase circuit, if any part is unbalanced, it is called an unbalanced three-phase circuit. In a three-phase circuit, the complex power absorbed by the three-phase load is equal to the sum of the complex power of each phase. The instantaneous power of a three-phase circuit is the sum of the instantaneous power of each phase load.

[0030] Furthermore, the term "coupled" in this document refers to any direct or indirect connection. Therefore, if the document describes a first circuit coupled to a second circuit, it means that the first circuit can be directly connected to the second circuit via electrical connection or signal connection methods such as wireless transmission or optical transmission, or indirectly connected to the second circuit via other circuits or connection methods via electrical connection or signal connection.

[0031] In some embodiments, the first voltage anomaly detection circuit 101 may specifically include any reasonable circuit unit with signal processing function, such as a control chip, a DSP (Digital Signal Processing) chip, an MCU (Micro Controller Unit) circuit, a CPU (Central Processing Unit), a microcontroller, a field-programmable gate array, a programmable logic device, discrete gate or transistor logic devices, or discrete hardware. This application does not limit this.

[0032] Specifically, the first voltage anomaly detection circuit 101 is used to sample and obtain the three-phase line voltage from the three-phase power supply circuit 102 in real time, or to obtain the three-phase line voltage from the three-phase power supply circuit 102 using a specific sampling frequency, such as the A-phase-B phase line voltage U. ab B-phase to C-phase line voltage U bc C-phase to A-phase line voltage U ca .

[0033] In some embodiments, the three-phase line voltage can be obtained by one or more of any reasonable sampling methods such as voltage transformer, sampling resistor, ADC (analog to digital converter), Hall sensor or circuit model estimation, and this application does not limit it.

[0034] It is worth noting that the three-phase line voltage can be specifically understood as the instantaneous amplitude value of the line voltage between each two phases of the three-phase power supply circuit 102, without including the phase of each line voltage. Of course, in other embodiments, the three-phase line voltage may also include the instantaneous amplitude value of the line voltage between each two phases and the phase of each line voltage, and this application does not limit this.

[0035] S12: The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of the three-phase line voltages.

[0036] The amplitude of each phase line voltage in the three-phase line voltage, i.e., the A-phase - B-phase line voltage U ab B-phase to C-phase line voltage U bc C-phase to A-phase line voltage U ca Take the absolute value of each amplitude, and then sum the absolute values ​​of each amplitude to obtain the reference voltage value Usum, that is, the reference voltage value Usum = |U ab |+|U bc |+|U ca |

[0037] Here, "absolute amplitude value" refers to the absolute value of the instantaneous amplitude value.

[0038] S13: Detect whether the cumulative characteristic parameter whose reference voltage value is not within the set threshold range is less than the set threshold.

[0039] The set threshold range is obtained by fitting the sum of the absolute values ​​of the amplitudes of the line voltages of each phase during the normal power supply process of the three-phase power circuit 102 and the threshold range it falls within, or by fitting characteristic parameters such as the system rated voltage, allowable fluctuation range (e.g., ±10%), and noise level calibration. Furthermore, the set threshold value is obtained by fitting based on the actual need to avoid misjudgment due to transient interference and improve robustness. In addition, this set threshold range and / or the set threshold value can also be adaptively adjusted according to the load or historical data.

[0040] Specifically, in each set detection cycle or each specific sampling cycle, it is detected whether the currently acquired reference voltage value Usum is within the set threshold range. For the detection results where the reference voltage value Usum is determined to be outside the set threshold range, one or more of the following reasonable features are extracted: cumulative counting, cumulative timing, and obtaining the corresponding abnormal proportion within the sliding window, in order to obtain a cumulative feature parameter. Then, it is detected whether the cumulative feature parameter is not less than the set threshold.

[0041] It is worth noting that if the reference voltage value Usum exceeds the set threshold range, this will be regarded as an "abnormal event" and the cumulative characteristic parameters will be updated, such as the number of consecutive abnormalities, the duration of the abnormality, or the number of abnormal points in the sliding window.

[0042] If the cumulative feature parameter is not less than the set threshold, then S14 is executed; if the cumulative feature parameter is less than the set threshold, then S11 is executed to acquire voltage and determine anomalies in the next sampling cycle; or the voltage is acquired in real time and anomalies are determined in the next detection cycle.

[0043] S14: It has been determined that there is a voltage anomaly in the three-phase line voltage.

[0044] If the cumulative characteristic parameter is determined to be not less than a set threshold, such as any reasonable number of abnormalities such as 3, 5 or 6 consecutive times, or any reasonable duration such as the cumulative abnormality time exceeding 100μs (microseconds), 1ms (milliseconds) or 2ms, then it is determined that there is a voltage abnormality in the three-phase line voltage, and one or more of the following responses to the voltage abnormality are issued, such as alarm indication, switching to backup power supply, or triggering voltage compensation. This application does not limit the scope of these responses.

[0045] The above scheme uses a reference voltage value Usum to detect the cumulative number of anomalies, effectively avoiding the need to detect the effective value of the three-phase AC voltage within an AC cycle. This allows for faster detection, facilitating quicker response and power restoration to maintain power supply stability and prevent data loss or damage to circuit components. Furthermore, it has low computational complexity, high accuracy, and is easy to implement in engineering. The cumulative anomaly detection also avoids misjudgments due to transient interference, improving robustness.

[0046] Furthermore, using line voltage (rather than phase voltage) avoids the influence of neutral point drift, making it more suitable for three-phase three-wire systems. This operation is sensitive to anomalies such as three-phase imbalance, phase loss, and voltage dips / sudden rises. For example, in the case of phase loss, the line voltages of two phases may be close to normal, but the absence of the third phase causes a significant drop in the total. Using the above method, voltage anomalies such as three-phase balanced voltage dips (overall decrease, significantly below the lower limit), single-phase power outages (phase loss, the remaining two phases approximately equal to line voltage), two-phase short circuits (related line voltages approach 0, the total drops significantly), three-phase voltage imbalances (small changes in the total; if only phase shifts occur, they may be missed), and high-frequency noise interference (instantaneous fluctuations, but the accumulation mechanism can suppress false alarms) can be effectively detected, making it widely applicable.

[0047] Furthermore, in some embodiments, the above-mentioned S11 may further include: acquiring the three-phase line voltage in the three-phase power supply circuit 102 using a preset sampling frequency.

[0048] Understandably, the sampling and anomaly detection of the three-phase line voltage by the first voltage anomaly detection circuit 101 can be performed cyclically within each preset sampling period (corresponding to the preset sampling frequency).

[0049] The preset sampling period can be 10μs to 100μs, preferably 20μs, but this application does not limit it.

[0050] For ease of understanding, let's take the detection of voltage anomalies as an example, specifically detecting a power outage in a three-phase power supply circuit 102. Please refer to [link / reference needed]. Figure 3 and Figure 4 ,in, Figure 3 This is a schematic diagram of an embodiment of the three-phase line voltage in a three-phase power supply system with a neutral line. Figure 4 This is a schematic diagram of an embodiment of the three-phase line voltage in a three-phase power supply system without a neutral wire.

[0051] Among them, the line voltage U between phase A and phase B ab B-phase to C-phase line voltage U bc C-phase to A-phase line voltage U ca With the same frequency, equal potential amplitude (voltage peak value), and a phase difference of 120°, it can be expressed as: (Equation 1) in, It is the angular frequency, U m It is the potential amplitude (voltage peak value).

[0052] The sum of the three-phase symmetrical line voltages is 0, which can be expressed as: (Equation 2) Please continue reading. Figure 5 and Figure 6 , Figure 5 This is a waveform diagram of an embodiment of symmetrical three-phase line voltage. Figure 6 This is a waveform diagram of an embodiment of the sum of the absolute values ​​of symmetrical three-phase line voltages.

[0053] Among them, such as Figure 5 As shown in Table 1 below, the relationship between the three line voltages and 0 corresponding to different angle intervals of the three-phase symmetrical line voltage can be divided into two cases: two line voltages are not greater than 0 and one line voltage is greater than 0; two line voltages are not less than 0 and one line voltage is less than 0.

[0054] Table 1 - Relationship between line voltage and zero for different angle intervals

[0055] According to Table 1 above, the absolute values ​​of line voltages corresponding to different angle intervals can be obtained, and thus the sum of the absolute values ​​of line voltages corresponding to different angle intervals (reference voltage value Usum) can be obtained.

[0056] Table 2 - Sum of absolute values ​​of line voltage corresponding to different angle intervals

[0057] By combining Equation 2 and Table 2, we can obtain the expression and numerical range of the sum of absolute values ​​of line voltage (reference voltage value Usum) corresponding to different angle intervals.

[0058] Table 3 - Expressions and numerical ranges for the sum of absolute values ​​of line voltages corresponding to different angle intervals

[0059] Understandably, as shown in Table 3 above and Figure 6 As shown, when all three line voltages are in normal condition, the sum of the absolute values ​​of the line voltages (reference voltage value Usum) has a range of values. When all three line voltages drop to 0V or very close to 0V, the sum of the absolute values ​​of the line voltages (reference voltage value Usum) is also 0V or very close to 0V. Therefore, this can be used as a criterion to fit and set a set threshold range or a power-off threshold range close to 0V. By comparing the reference voltage value Usum with the set threshold range multiple times, and determining that the reference voltage value Usum is not within the set threshold range, it can be determined that there is a voltage anomaly; or, by comparing the reference voltage value Usum with the power-off threshold range multiple times, and determining that the reference voltage value Usum is within the power-off threshold range, it can be determined that there is a voltage anomaly, thereby determining whether the three-phase AC is in a normal state or a power-off state.

[0060] Of course, in other embodiments, when the voltage anomaly detection method corresponds to detecting undervoltage or overvoltage anomalies in the three-phase power supply circuit 102, the reference voltage value Usum remains within the normal range. This allows us to fit and set the threshold range, or the undervoltage threshold range or the overvoltage threshold range, and then determine whether the three-phase AC is in a normal state, an undervoltage state, or an overvoltage state through multiple threshold comparisons. This will not be elaborated further here.

[0061] Please see Figure 7 , Figure 7 This is a flowchart illustrating the second embodiment of the voltage anomaly detection method of this application. The voltage anomaly detection method of this embodiment... Figure 1 A detailed implementation diagram of the voltage anomaly detection method is shown, which specifically includes the following steps: S21: Obtain the three-phase line voltage in the three-phase power supply circuit.

[0062] S22: The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of the three-phase line voltages.

[0063] Among them, S21 and S22 are respectively with Figure 1 S11 and S12 are the same. Please refer to the textual descriptions of S11 and S12 for details, which will not be repeated here.

[0064] S23: Detect whether the reference voltage value is within the set threshold range.

[0065] The first voltage anomaly detection circuit 101 obtains a set threshold range by fitting the sum of the absolute values ​​of the amplitudes of the phase line voltages during the normal power supply process of the three-phase power supply circuit 102 or the sum of the absolute values ​​of the phase line voltages during the simulation experiment, i.e. the threshold range where the reference voltage value Usum is located, in order to detect whether the currently acquired reference voltage value Usum is within the set threshold range.

[0066] If the reference voltage value Usum is not within the set threshold range, then S24 is executed; if the reference voltage value Usum is within the set threshold range, then S27 is executed.

[0067] S24: Check if the cumulative number of abnormalities is less than the set number.

[0068] When it is determined that the reference voltage value Usum is not within the set threshold range, that is, when there is a voltage anomaly in the currently sampled three-phase line voltage, the current cumulative number of anomalies is further detected, that is, whether the cumulative number of anomalies detected is less than the set number.

[0069] In some embodiments, the set number of times can be any reasonable number such as 3 times, 5 times or 6 times, and this application does not limit it.

[0070] If the cumulative number of exceptions is less than the set number, then execute S25; if the cumulative number of exceptions is not less than the set number, then execute S26.

[0071] S25: Increment the cumulative number of anomalies by 1.

[0072] If the current cumulative number of anomalies is determined to be less than the set number, the cumulative number of anomalies is incremented by 1, and the process returns to execute S21, which means sampling the three-phase line voltage again to perform anomaly detection again.

[0073] S26: It has been determined that there is an abnormal voltage in the three-phase line voltage.

[0074] When it is determined that the current cumulative number of abnormalities is not less than the set number, it is determined that there is a voltage abnormality in the three-phase line voltage, and the cumulative number of abnormalities is kept at the set number, that is, it is no longer added by 1, to prevent the addition overflow.

[0075] Meanwhile, the first voltage anomaly detection circuit 101 is also used to issue alarm indications, switch to backup power, trigger voltage compensation, and perform one or more of any reasonable control processes in response to voltage anomalies, which are not limited in this application.

[0076] S27: Check if the cumulative number of abnormalities is greater than 0.

[0077] Once the reference voltage value Usum is determined to be within the set threshold range, meaning that there is no voltage abnormality in the currently sampled three-phase line voltage, the current cumulative number of abnormalities is further detected, i.e., whether the cumulative number of abnormalities detected is greater than 0.

[0078] If the cumulative number of exceptions is greater than 0, then execute S28; if the cumulative number of exceptions is not greater than 0, then execute S29.

[0079] S28: Decrease the cumulative number of anomalies by 1.

[0080] If the current cumulative number of anomalies is determined to be greater than 0, the cumulative number of anomalies is decremented by 1, and the process returns to execute S21, which means sampling the three-phase line voltage again to perform anomaly detection again.

[0081] S29: Confirm that there are no abnormalities in the three-phase line voltages and keep the cumulative number of abnormalities unchanged.

[0082] When the current cumulative number of abnormalities is determined to be no greater than 0, the three-phase line voltage is determined to be normal, that is, the three-phase power supply circuit 102 is in normal working state, or has recovered from the abnormal state to normal state, and the cumulative number of abnormalities remains unchanged, that is, it remains 0, in order to prevent subtraction overflow.

[0083] The above scheme uses the accumulated line voltage amplitude as a benchmark, combined with an incrementing and decrementing recovery mechanism for the number of anomalies, to achieve robust judgment of voltage anomalies. A single voltage fluctuation will not immediately trigger an alarm; multiple consecutive anomalies are required to determine a fault. During normal operation, the system automatically "recovers" (decrements) to avoid continuous false alarms caused by occasional disturbances. The accumulated number of anomalies is incremented by 1 during anomalies and decremented by 1 during normal operation, creating a "hysteresis" behavior to prevent frequent state switching near threshold boundaries (anti-bouncing), and possesses a memory and recovery mechanism.

[0084] Please see Figure 8 , Figure 8 This is a flowchart illustrating the third embodiment of the voltage anomaly detection method of this application. The voltage anomaly detection method of this embodiment... Figure 1 A detailed implementation diagram of the voltage anomaly detection method is shown, which specifically includes the following steps: S31: Obtain the three-phase line voltage in the three-phase power supply circuit.

[0085] S32: The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of the three-phase line voltages.

[0086] Among them, S31 and S32 are respectively with Figure 1 S11 and S12 are the same. Please refer to the textual descriptions of S11 and S12 for details, which will not be repeated here.

[0087] S33: Detect whether the reference voltage value is less than the power-off threshold.

[0088] Based on the characteristics of voltage change when the three-phase power supply circuit 102 is powered off, the sum of the absolute values ​​of the amplitudes of each phase line voltage and the corresponding power-off threshold U1 are obtained, or the rated peak voltage of the three-phase line voltage is multiplied by a set multiple to obtain the power-off threshold U1, so as to detect whether the currently acquired reference voltage value Usum is less than the power-off threshold U1.

[0089] In some embodiments, the set multiple is less than 0.5, greater than 0, and preferably 0.2, but this application does not limit it.

[0090] If the reference voltage value Usum is less than the power-down threshold U1, then S34 is executed; if the reference voltage value Usum is not less than the power-down threshold U1, then S37 is executed.

[0091] S34: Detect whether the power failure timer value is less than the set time threshold.

[0092] When the reference voltage value Usum is determined to be less than the power outage threshold U1, indicating a power outage anomaly, the current power outage timer value is further checked to see if it is less than the set time threshold.

[0093] Understandably, this set time threshold is used for timing confirmation to eliminate the interference caused by sampling noise and short-term voltage fluctuations on power failure judgment, ensuring that power failure judgment is accurate and reliable.

[0094] In some embodiments, the value of the set time threshold ranges from 0.1ms to 2ms, preferably 1ms, but this application does not limit it.

[0095] If the power outage timer value is less than the set time threshold, then S35 is executed; if the power outage timer value is not less than the set time threshold, then S36 is executed.

[0096] S35: Add a step value to the power failure timer value.

[0097] If the current power outage timer value is determined to be less than the set time threshold, the power outage timer value is increased by a step value, and the process returns to execute S31, that is, to sample and obtain the three-phase line voltage again in order to perform anomaly detection again.

[0098] The step value can be understood as a tolerance value given based on the power failure time value corresponding to the cumulative time of a specific storage bit or timer, in response to each power failure anomaly detection result.

[0099] S36: Determine that there is a power outage anomaly in the three-phase line voltage and set the power outage flag to 1.

[0100] If the current power outage timer value is determined to be not less than the set time threshold, then a power outage anomaly is identified in the three-phase line voltage, and the power outage flag is set to 1. At the same time, the power outage timer value is kept at the set time threshold, i.e., no further increments are made to prevent overflow during addition.

[0101] Meanwhile, the first voltage anomaly detection circuit 101 is also used to issue alarm indications, switch to backup power, trigger voltage compensation, and perform one or more of any reasonable control processes in response to voltage anomalies, which are not limited in this application.

[0102] S37: Detect whether the power failure timer value is greater than the step value.

[0103] If the reference voltage value Usum is not less than the power outage threshold U1, that is, if there is no voltage abnormality in the currently sampled three-phase line voltage, then further detect whether the current power outage time value is greater than the step value.

[0104] If the power-down timer value is greater than the step value, then execute S38; if the power-down timer value is not greater than the step value, then execute S39.

[0105] S38: Subtract the step value from the power failure timer value.

[0106] If the current power failure timer value is determined to be greater than the step value, the power failure timer value is reduced by one step value, and the process returns to execute S31, that is, to sample and obtain the three-phase line voltage again for abnormal detection.

[0107] S39: Set the power failure timer value to 0 and set the power failure flag to 0.

[0108] When it is determined that the current power-down timer value is not greater than the step value, it is judged that there is no abnormality in the three-phase line voltage, that is, the three-phase power supply circuit 102 is in normal working condition, or has recovered from an abnormal state to normal state, and the power-down flag is set to 0. At the same time, the power-down timer value is kept unchanged, that is, it remains at 0, to prevent subtraction overflow.

[0109] The above scheme, by adding a step value to the power-down timing value during abnormal events and subtracting the step value during normal events, forms a "hysteresis" behavior, preventing frequent state switching near the threshold boundary (debouncing), and has a memory and recovery mechanism.

[0110] Furthermore, in some embodiments, the above-mentioned S35 can be replaced by multiplying the power-down timing value by an adjustment coefficient.

[0111] The adjustment coefficient is greater than 1, and can be 1.05 to 1.5, preferably 1.1. This application does not limit it.

[0112] Furthermore, in some embodiments, the above-mentioned S38 can be replaced by dividing the power-down timing value by the adjustment coefficient.

[0113] Please see Figure 9 , Figure 9 This is a flowchart illustrating the fourth embodiment of the voltage anomaly detection method of this application. The voltage anomaly detection method of this embodiment... Figure 1 A detailed implementation diagram of the voltage anomaly detection method is shown, which specifically includes the following steps: S41: Obtain the three-phase line voltage in the three-phase power supply circuit.

[0114] S42: The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of the three-phase line voltages.

[0115] Among them, S41 and S42 are respectively with Figure 1 S11 and S12 are the same. Please refer to the textual descriptions of S11 and S12 for details, which will not be repeated here.

[0116] S43: Perform band-stop filtering on the reference voltage value to obtain the average value of the reference voltage.

[0117] To improve the robustness of voltage anomaly detection, when acquiring the reference voltage value Usum, a band-stop filter or a corresponding band-stop filtering algorithm is used to perform band-stop filtering on the reference voltage value Usum to obtain the average reference voltage value Usum1.

[0118] It is worth noting that band-stop filtering is a filtering method that specifically "blocks" signals of a particular frequency while allowing other frequencies to pass normally. Its core function is exactly the opposite of band-pass filtering.

[0119] Band-stop filters are typically composed of a low-pass filter and a high-pass filter connected in parallel. The low-pass section allows signals below the cutoff frequency to pass through, while the high-pass section allows signals above the cutoff frequency to pass through. The outputs of the two filters are then added together, resulting in the cancellation or significant attenuation of the intermediate frequency range. Ideally, the gain in the blocked frequency band is zero, while signals within the passband are essentially unaffected.

[0120] S44: Detect whether the average value of the reference voltage is less than the undervoltage threshold.

[0121] Understandably, the frequency of the reference voltage value Usum is 6 times the grid frequency. Band-stop filtering of the reference voltage value Usum yields its average value, i.e., the average reference voltage value Usum1. As shown in Table 3 above, the average reference voltage value Usum1 is 0.5. ( Um + 2Um) ≈ 1.866U m Therefore, when the filter stopband frequency is set to (6... Grid frequency -5 Hz) ~ (6 At a power grid frequency of +5 Hz, 6 can be filtered out. The power grid frequency component is included, while other components are retained.

[0122] The band-stop filter can be of second order or higher, with 5Hz (hertz) corresponding to the stopband bandwidth being the preferred frequency, but it can also be 4Hz, 6Hz or other reasonable frequencies. This application does not impose any restrictions on this.

[0123] In addition, the grid frequency can be calculated by detecting the interval between two zero-crossing points of the line voltage, or by using a frequency-locked loop, or by obtaining it from the upper-level monitoring, or by default the rated grid frequency. This application does not impose any restrictions on this.

[0124] Under normal operating conditions of the three-phase power supply circuit 102, the average value of the reference voltage Usum1 is 1.866. U m At that time, the undervoltage threshold U2 used for undervoltage anomaly detection can be obtained by fitting the set value. For example, let the undervoltage threshold U2 = 1.866. Un k1 and Un are the rated peak voltages, and k1 is the undervoltage reference coefficient.

[0125] When the undervoltage threshold U2 is set, it is checked whether the average value of the currently acquired reference voltage Usum1 is less than the undervoltage threshold U2.

[0126] In some embodiments, the undervoltage threshold U2 is the product of the rated peak voltage of the three-phase line voltage and the undervoltage coefficient, which is less than... This application does not impose any restrictions.

[0127] In some embodiments, the undervoltage coefficient is the product of the undervoltage reference coefficient and 1.866, i.e., 1.866. k1, the undervoltage reference coefficient k1 is 0.5~0.9, and preferably 0.85, but this application does not limit it.

[0128] If the average reference voltage Usum1 is less than the undervoltage threshold U2, then S45 is executed; if the average reference voltage Usum1 is not less than the undervoltage threshold U2, then S48 is executed.

[0129] S45: Detect whether the undervoltage timing value is less than the set time threshold.

[0130] When the average reference voltage Usum1 is determined to be less than the undervoltage threshold U2, indicating an undervoltage anomaly, the current undervoltage timing value is further checked to see if it is less than the set time threshold.

[0131] Understandably, this set time threshold is used for timing confirmation to eliminate sampling noise and interference from short-term voltage fluctuations on undervoltage judgment, ensuring accurate and reliable undervoltage judgment.

[0132] In some embodiments, the value of the set time threshold ranges from 0.1ms to 2ms, preferably 1ms, but this application does not limit it.

[0133] If the undervoltage timer value is less than the set time threshold, then S46 is executed; if the undervoltage timer value is not less than the set time threshold, then S47 is executed.

[0134] S46: Add the step value to the undervoltage timing value.

[0135] When it is determined that the current undervoltage timing value is less than the set time threshold, the undervoltage timing value is increased by a step value, and the process returns to execute S41, that is, to sample and obtain the three-phase line voltage again for abnormal detection.

[0136] The step value can be understood as a tolerance value given based on the undervoltage timing value corresponding to the cumulative timing of a specific storage bit or timer in response to each undervoltage anomaly detection result.

[0137] S47: Determine that there is an undervoltage anomaly in the three-phase line voltage and set the undervoltage flag to 1.

[0138] If the current undervoltage timing value is determined to be not less than the set time threshold, an undervoltage anomaly is identified in the three-phase line voltage, and the undervoltage flag is set to 1. At the same time, the undervoltage timing value is kept at the set time threshold, i.e., no further increments are made to prevent overflow during addition.

[0139] Meanwhile, the first voltage anomaly detection circuit 101 is also used to issue alarm indications, switch to backup power, trigger voltage compensation, and perform one or more of any reasonable control processes in response to voltage anomalies, which are not limited in this application.

[0140] S48: Detect whether the undervoltage timing value is greater than the step value.

[0141] Once it is determined that the average value of the reference voltage Usum1 is not less than the undervoltage threshold U2, i.e. there is no undervoltage anomaly in the currently sampled three-phase line voltage, the current undervoltage timing value is further checked to see if it is greater than the step value.

[0142] If the undervoltage timing value is greater than the step value, then execute S49; if the undervoltage timing value is not greater than the step value, then execute S410.

[0143] S49: Subtract the step value from the undervoltage timing value.

[0144] If the current undervoltage timing value is determined to be greater than the step value, the undervoltage timing value is reduced by one step value, and the process returns to execute S41, that is, to sample and obtain the three-phase line voltage again for abnormal detection.

[0145] S410: Set the undervoltage timer value to 0 and set the undervoltage flag to 0.

[0146] When the current undervoltage timing value is determined to be no greater than the step value, it is determined that the three-phase line voltage is normal, that is, the three-phase power supply circuit 102 is in normal working condition or has recovered from an abnormal state to normal condition, and the undervoltage flag is set to 0. At the same time, the undervoltage timing value is kept unchanged, that is, it remains at 0, to prevent subtraction overflow.

[0147] The above scheme, by adding a step value to the undervoltage timing value during abnormal conditions and subtracting the step value from the undervoltage timing value during normal conditions, forms a "hysteresis" behavior, preventing frequent state switching near the threshold boundary (debouncing), and has a memory and recovery mechanism.

[0148] Furthermore, in some embodiments, the above-mentioned S43 specifically includes: using a filtering characteristic function to process the reference voltage value Usum to obtain the reference voltage average value Usum1.

[0149] Please continue reading. Figure 10 , Figure 10 yes Figure 9 A flowchart illustrating an embodiment of S43 is shown. In one embodiment, the voltage anomaly detection method of this application, in addition to the above-described S41-S410, further includes some more specific steps. Specifically, S43 may further include the following steps: S431: Send the reference voltage value to the band-stop filter so that the band-stop filter can perform band-stop filtering on the reference voltage value to obtain the average value of the reference voltage.

[0150] Understandably, the band-stop filtering of the reference voltage value Usum can also be achieved through an external band-stop filter.

[0151] Specifically, the first voltage anomaly detection circuit 101 sends the reference voltage value Usum to the band-stop filter, so that the reference voltage value Usum is subjected to band-stop filtering to obtain the average reference voltage value Usum1.

[0152] S432: Receive the average value of the reference voltage transmitted corresponding to the band-stop filter.

[0153] The first voltage anomaly detection circuit 101 receives the average value of the reference voltage Usum1 returned by the band-stop filter.

[0154] Of course, in other embodiments, the band-stop filter may also be integrated into the first voltage anomaly detection circuit 101, and this application does not limit this.

[0155] Please see Figure 11 , Figure 11 This is a flowchart illustrating the fifth embodiment of the voltage anomaly detection method of this application. The voltage anomaly detection method of this embodiment... Figure 9 A detailed implementation diagram of the voltage anomaly detection method is shown, which specifically includes the following steps: S51: The three-phase instantaneous line voltage in the three-phase power supply circuit is obtained by setting the sampling frequency.

[0156] The first voltage anomaly detection circuit 101 periodically acquires the three-phase instantaneous line voltage from the three-phase power supply circuit 102 using a fixed set sampling frequency.

[0157] S52: The reference instantaneous voltage value is obtained by summing the absolute values ​​of the instantaneous amplitudes of the instantaneous line voltages of each phase in the three-phase instantaneous line voltage.

[0158] The absolute values ​​of the instantaneous amplitudes of the instantaneous line voltages of each phase in the three-phase line voltages are taken respectively, and the absolute values ​​of the instantaneous amplitudes are accumulated to obtain the reference instantaneous voltage value.

[0159] S53: Check whether the cumulative number of reference instantaneous voltage values ​​acquired is less than the set number.

[0160] To avoid misjudgment due to transient interference and improve robustness, a set number is obtained by fitting the period difference between voltage sampling and anomaly detection to detect whether the cumulative number of currently acquired reference transient voltage values ​​is less than the set number.

[0161] In some embodiments, the number of settings can be 2 to 6, and preferably 3. This application does not limit this number.

[0162] If the cumulative number of reference instantaneous voltage values ​​acquired is less than the set number, then S54 is executed; if the cumulative number of reference instantaneous voltage values ​​acquired is not less than the set number, then S55 is executed.

[0163] S54: Increment the cumulative number of acquisitions by 1.

[0164] If the cumulative number of times the reference instantaneous voltage value is obtained is less than the set number, the cumulative number of times is incremented by 1, and the process returns to execute S51, that is, to sample and obtain a three-phase instantaneous line voltage again.

[0165] S55: Calculate the average value of the reference voltage by averaging the set number of instantaneous reference voltage values.

[0166] When the cumulative number of reference instantaneous voltage values ​​acquired is not less than the set number, the arithmetic mean of the set number of reference instantaneous voltage values ​​acquired sequentially, such as 3 or 5, is calculated to obtain the reference voltage average value Usum1.

[0167] Understandably, by collecting multiple instantaneous samples within a set time window and then averaging them, a more stable and interference-resistant voltage reference value can be obtained. Instantaneous values ​​are susceptible to switching noise and electromagnetic interference; averaging can significantly suppress random disturbances and resist high-frequency noise. This average reference voltage, Usum1, can serve as a stable input reference in the "voltage anomaly detection method," adapting to subsequent anomaly detection.

[0168] S56: Detect whether the average value of the reference voltage is less than the undervoltage threshold.

[0169] S57: Detect whether the undervoltage timing value is less than the set time threshold.

[0170] S58: Add the step value to the undervoltage timing value.

[0171] S59: Determine that there is an undervoltage anomaly in the three-phase line voltage and set the undervoltage flag to 1.

[0172] S510: Detects whether the undervoltage timing value is greater than the step value.

[0173] S511: Subtract the step value from the undervoltage timing value.

[0174] S512: Set the undervoltage timer value to 0 and set the undervoltage flag to 0.

[0175] Among them, S56, S57, S58, S59, S510, S511 and S512 are respectively with Figure 9 S44, S45, S46, S47, S48, S49, and S410 are the same. For details, please refer to S44, S45, S46, S47, S48, S49, and S410 and their related textual descriptions. They will not be repeated here.

[0176] It is worth noting that when the reference voltage value Usum is subjected to band-stop filtering processing using the signal processing steps described in S51 to S55 to obtain the reference voltage average value Usum1, the undervoltage threshold U2 or undervoltage coefficient corresponding to it must be less than the undervoltage threshold U2 or undervoltage coefficient corresponding to the reference voltage average value Usum1 obtained by using a band-stop filter or the corresponding band-stop filtering function algorithm.

[0177] Please see Figure 12 , Figure 12 This is a flowchart illustrating the sixth embodiment of the voltage anomaly detection method of this application. The voltage anomaly detection method of this embodiment... Figure 1 A detailed implementation diagram of the voltage anomaly detection method is shown, which specifically includes the following steps: S61: Obtain the three-phase line voltage in a three-phase power supply circuit.

[0178] S62: The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of the three-phase line voltages.

[0179] Among them, S61 and S62 are respectively with Figure 1 S11 and S12 are the same. Please refer to the textual descriptions of S11 and S12 for details, which will not be repeated here.

[0180] S63: Perform band-stop filtering on the reference voltage value to obtain the average value of the reference voltage.

[0181] When obtaining the reference voltage value Usum, the reference voltage value Usum is subjected to band-stop filtering through a band-stop filter or a corresponding band-stop filtering function algorithm, or the signal processing steps described in S51~S55 to obtain the average reference voltage value Usum1.

[0182] S64: Detect whether the average value of the reference voltage is greater than the overvoltage threshold.

[0183] Under normal operating conditions of the three-phase power supply circuit 102, the average value of the reference voltage Usum1 is 1.866. U m At that time, the overpressure threshold U3 used for overpressure anomaly detection can be obtained by fitting the set value. For example, let the overpressure threshold U3 = 1.866. Un k2 and Un are the rated peak voltages, and k2 is the overvoltage reference coefficient.

[0184] When the overvoltage threshold U3 is set, check whether the average value of the currently acquired reference voltage Usum1 is less than the overvoltage threshold U3.

[0185] In some embodiments, the overvoltage threshold U3 is the product of the rated peak voltage of the three-phase line voltage and the overvoltage coefficient, which is greater than 2, and is not limited in this application.

[0186] In some embodiments, the overpressure coefficient is the product of the overpressure reference coefficient and 1.866, i.e., 1.866. k2, the overpressure reference coefficient k2 is 1.1~1.3, and preferably 1.15, but this application does not limit it.

[0187] If the average reference voltage Usum1 is greater than the overvoltage threshold U3, then S65 is executed; if the average reference voltage Usum1 is not greater than the overvoltage threshold U3, then S68 is executed.

[0188] S65: Detect whether the overvoltage timing value is less than the set time threshold.

[0189] When the average reference voltage Usum1 is determined to be greater than the overvoltage threshold U3, indicating an overvoltage anomaly, the current overvoltage timing value is further checked to see if it is less than the set time threshold.

[0190] Understandably, this set time threshold is used for timing confirmation to eliminate sampling noise and interference from short-term voltage fluctuations on overvoltage judgment, ensuring that overvoltage judgment is accurate and reliable.

[0191] In some embodiments, the value of the set time threshold ranges from 0.1ms to 2ms, preferably 1ms, but this application does not limit it.

[0192] If the overvoltage timing value is less than the set time threshold, then S66 is executed; if the overvoltage timing value is not less than the set time threshold, then S67 is executed.

[0193] S66: Add the step value to the overvoltage timing value.

[0194] When it is determined that the current overvoltage timing value is less than the set time threshold, the overvoltage timing value is increased by a step value, and the process returns to execute S61, that is, to sample and obtain the three-phase line voltage again for abnormal detection.

[0195] The step value can be understood as a tolerance value given based on the overvoltage timing value corresponding to the cumulative timing of a specific storage bit or timer in response to each overvoltage anomaly detection result.

[0196] S67: Determine that there is an overvoltage anomaly in the three-phase line voltage and set the overvoltage flag to 1.

[0197] If the current overvoltage timing value is determined to be not less than the set time threshold, an overvoltage anomaly is identified in the three-phase line voltage, and the overvoltage flag is set to 1. At the same time, the overvoltage timing value is kept at the set time threshold, i.e., no further increments are made to prevent overflow during addition.

[0198] Meanwhile, the first voltage anomaly detection circuit 101 is also used to issue alarm indications, switch to backup power, trigger voltage compensation, and perform one or more of any reasonable control processes in response to voltage anomalies, which are not limited in this application.

[0199] S68: Detect whether the overvoltage timing value is greater than the step value.

[0200] Once it is determined that the average value of the reference voltage Usum1 is not greater than the overvoltage threshold U3, that is, there is no overvoltage anomaly in the currently sampled three-phase line voltage, the current overvoltage timing value is further checked to see if it is greater than the step value.

[0201] If the overvoltage timing value is greater than the step value, then S69 is executed; if the overvoltage timing value is not greater than the step value, then S610 is executed.

[0202] S69: Subtract the step value from the overvoltage timing value.

[0203] If the current overvoltage timing value is determined to be greater than the step value, the overvoltage timing value is reduced by one step value, and the process returns to execute S61, that is, to sample and obtain the three-phase line voltage again for abnormal detection.

[0204] S610: Set the overvoltage timing value to 0 and set the overvoltage flag to 0.

[0205] When the current overvoltage timing value is determined to be no greater than the step value, it is determined that the three-phase line voltage is normal, that is, the three-phase power supply circuit 102 is in normal working condition or has recovered from an abnormal state to normal condition, and the overvoltage flag is set to 0. At the same time, the overvoltage timing value is kept unchanged, that is, it remains at 0, to prevent subtraction overflow.

[0206] The above scheme, by adding a step value to the overvoltage timing value during abnormal conditions and subtracting the step value from the overvoltage timing value during normal conditions, forms a "hysteresis" behavior, preventing frequent state switching near the threshold boundary (anti-shake), and has a memory and recovery mechanism.

[0207] It is worth noting that when the reference voltage value Usum is subjected to band-stop filtering in the signal processing steps described in S51 to S55 to obtain the average reference voltage Usum1, the overvoltage threshold U3 or overvoltage coefficient corresponding to it must be greater than the overvoltage threshold U3 or overvoltage coefficient corresponding to the average reference voltage Usum1 obtained by using a band-stop filter or the corresponding band-stop filtering function algorithm.

[0208] This application also provides an electronic device, please refer to... Figure 13 , Figure 13 This is a schematic diagram of one embodiment of the electronic device of this application. In this embodiment, the electronic device 70 includes a housing 71 and a second voltage abnormality detection circuit 72 connected to the housing 71.

[0209] It should be noted that the second voltage anomaly detection circuit 72 described in this embodiment is the first voltage anomaly detection circuit 101 described in any of the above embodiments. Please refer to [link / reference] for details. Figures 1-12 The relevant textual content will not be elaborated upon here.

[0210] The beneficial effects of this application are as follows: Unlike existing technologies, the voltage anomaly detection method provided in this application acquires the three-phase line voltages in a three-phase power supply circuit, accumulates the absolute values ​​of the amplitudes of each phase line voltage to obtain a reference voltage value, and performs cumulative anomaly detection based on this reference voltage value. This effectively avoids detecting the effective value of the three-phase AC voltage, eliminating the need to complete the detection within one AC cycle. Detection is faster, facilitating rapid response and power restoration to maintain power supply stability and prevent data loss, circuit component damage, and other consequences. Furthermore, it has low computational complexity, high accuracy, and is easy to implement in engineering. The cumulative anomaly detection method also avoids misjudgments due to transient interference, improving robustness.

[0211] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A voltage anomaly detection method, applied in a three-phase power supply circuit, characterized in that, The voltage anomaly detection method includes: Obtain the three-phase line voltages in the three-phase power supply circuit; The reference voltage value is obtained by summing the absolute values ​​of the amplitudes of each phase line voltage in the three-phase line voltage. Detect whether the cumulative characteristic parameter of the reference voltage value not being within the set threshold range is less than the set threshold; If the cumulative characteristic parameter is less than the set threshold, return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the cumulative characteristic parameter is not less than the set threshold, it is determined that there is a voltage anomaly in the three-phase line voltage.

2. The voltage anomaly detection method according to claim 1, characterized in that, The step of detecting whether the cumulative characteristic parameter of the reference voltage value, which is not within a set threshold range, is less than a set threshold includes: Detect whether the reference voltage value is within the set threshold range; If the reference voltage value is not within the set threshold range, check whether the cumulative number of abnormalities is less than the set number. If the cumulative number of anomalies is less than the set number, increment the cumulative number of anomalies by 1, and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the cumulative number of abnormalities is not less than the set number, it is determined that the three-phase line voltage has an abnormality.

3. The voltage anomaly detection method according to claim 2, characterized in that, The voltage anomaly detection method further includes: If the reference voltage value is within the set threshold range, check whether the cumulative number of abnormalities is greater than 0; If the cumulative number of anomalies is greater than 0, decrement the cumulative number of anomalies by 1, and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the cumulative number of abnormalities is equal to 0, it is determined that there is no abnormality in the three-phase line voltage, and the cumulative number of abnormalities remains unchanged.

4. The voltage anomaly detection method according to claim 1, characterized in that, The step of detecting whether the cumulative characteristic parameter of the reference voltage value, which is not within a set threshold range, is less than a set threshold includes: The reference voltage value is checked to see if it is less than the power outage threshold; the power outage threshold is a set multiple of the rated peak voltage of the three-phase line voltage, and the set multiple is less than 0.

5. If the reference voltage value is less than the power failure threshold, check whether the power failure timing value is less than the set time threshold. If the power failure timing value is less than the set time threshold, add a step value to the power failure timing value and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the power outage timing value is not less than the set time threshold, it is determined that there is a power outage anomaly in the three-phase line voltage, and the power outage flag is set to 1.

5. The voltage anomaly detection method according to claim 4, characterized in that, The voltage anomaly detection method further includes: If the reference voltage value is not less than the power-down threshold, detect whether the power-down timing value is greater than the step value; If the power failure timing value is greater than the step value, subtract the step value from the power failure timing value and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the power-down timer value is not greater than the step value, set the power-down timer value to 0 and set the power-down flag to 0.

6. The voltage anomaly detection method according to claim 1, characterized in that, The step of detecting whether the cumulative characteristic parameter of the reference voltage value, which is not within a set threshold range, is less than a set threshold includes: The reference voltage value is subjected to band-stop filtering to obtain the average value of the reference voltage; The system detects whether the average value of the reference voltage is less than an undervoltage threshold; the undervoltage threshold is the product of the rated peak voltage of the three-phase line voltage and the undervoltage coefficient, and the undervoltage coefficient is less than... ; If the average value of the reference voltage is less than the undervoltage threshold, check whether the undervoltage timing value is less than a set time threshold. If the undervoltage timing value is less than the set time threshold, add a step value to the undervoltage timing value and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the undervoltage timing value is not less than the set time threshold, it is determined that there is an undervoltage anomaly in the three-phase line voltage, and the undervoltage flag is set to 1.

7. The voltage anomaly detection method according to claim 6, characterized in that, The voltage anomaly detection method further includes: If the average value of the reference voltage is not less than the undervoltage threshold, detect whether the undervoltage timing value is greater than the step value; If the undervoltage timing value is greater than the step value, subtract the step value from the undervoltage timing value and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the undervoltage timing value is not greater than the step value, set the undervoltage timing value to 0 and set the undervoltage flag to 0.

8. The voltage anomaly detection method according to claim 1, characterized in that, The step of detecting whether the cumulative characteristic parameter of the reference voltage value, which is not within a set threshold range, is less than a set threshold includes: The reference voltage value is subjected to band-stop filtering to obtain the average value of the reference voltage; The average value of the reference voltage is detected to be greater than the overvoltage threshold; the overvoltage threshold is the product of the rated peak voltage of the three-phase line voltage and the overvoltage coefficient, and the overvoltage coefficient is greater than 2; If the average value of the reference voltage is greater than the overvoltage threshold, check whether the overvoltage timing value is less than the set time threshold. If the overvoltage timing value is less than the set time threshold, the overvoltage timing value is increased by a step value, and the process returns to the step of obtaining the three-phase line voltage in the three-phase power supply circuit. If the overvoltage timing value is not less than the set time threshold, it is determined that there is an overvoltage anomaly in the three-phase line voltage, and the overvoltage flag is set to 1.

9. The voltage anomaly detection method according to claim 8, characterized in that, The voltage anomaly detection method further includes: If the average value of the reference voltage is not greater than the overvoltage threshold, detect whether the overvoltage timing value is greater than the step value; If the overvoltage timing value is greater than the step value, subtract the step value from the overvoltage timing value and return to the step of obtaining the three-phase line voltage in the three-phase power supply circuit; If the overpressure timing value is not greater than the step value, set the overpressure timing value to 0 and set the overpressure flag to 0.

10. The voltage anomaly detection method according to any one of claims 6-9, characterized in that, The step of performing band-stop filtering on the reference voltage value to obtain the average value of the reference voltage includes: The reference voltage value is sent to a band-stop filter so that the band-stop filter performs band-stop filtering on the reference voltage value to obtain the average value of the reference voltage. Receive the average value of the reference voltage transmitted by the band-stop filter; Alternatively, the average value of the reference voltage can be obtained by performing calculations on the reference voltage value using a filtering characteristic function.

11. The voltage anomaly detection method according to any one of claims 6-9, characterized in that, The step of obtaining the three-phase line voltage in the three-phase power supply circuit includes: The instantaneous line voltages of the three-phase power supply circuit are obtained by setting a sampling frequency; The steps for obtaining the reference voltage value by summing the absolute values ​​of the amplitudes of each phase line voltage in the three-phase line voltage include: The reference instantaneous voltage value is obtained by summing the absolute values ​​of the instantaneous amplitudes of the instantaneous line voltages of each phase in the three-phase instantaneous line voltages. The step of performing band-stop filtering on the reference voltage value to obtain the average value of the reference voltage includes: Check whether the cumulative number of times the reference instantaneous voltage value has been acquired is less than a set number; If the cumulative number of acquisitions is less than the set number, the cumulative number of acquisitions is incremented by 1, and the process returns to the step of acquiring the three-phase instantaneous line voltage in the three-phase power supply circuit using the set sampling frequency. If the cumulative number of acquisitions is not less than the set number, the average value of the reference instantaneous voltage values ​​is calculated by averaging the set number of reference instantaneous voltage values ​​to obtain the average value of the reference voltage.

12. A voltage anomaly detection circuit, characterized in that, The voltage anomaly detection circuit is used to couple with the three-phase power supply circuit. The voltage anomaly detection circuit uses the voltage anomaly detection method as described in any one of claims 1-11 to control the three-phase power supply circuit.

13. An electronic device, characterized in that, The electronic device includes a housing and a voltage anomaly detection circuit connected to the housing; The voltage anomaly detection circuit is the voltage anomaly detection circuit as described in claim 12.

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