Identification method and device for living body electric shock of electrical device, and storage medium

Abstract

The embodiment of the invention provides a living body electric shock identification method and equipment for electrical equipment and a storage medium, and belongs to the technical field of low-voltage power distribution networks. The method comprises the following steps: judging whether a first electric shock triggering condition is met or not according to the amplitude of a total leakage current signal and a preset triggering amplitude threshold value; determining a first sub-period ratio and a second sub-period ratio according to the first electric shock current signal effective value, the second electric shock current signal effective value and the third electric shock current signal effective value; according to the first sub-period ratio and the second sub-period ratio, judging whether a second electric shock triggering condition is met or not; judging whether a third electric shock triggering condition is met or not according to the phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal; and when the first electric shock triggering condition, the second electric shock triggering condition and the third electric shock triggering condition are simultaneously satisfied, determining that the electrical equipment has a living body electric shock phenomenon. The accuracy of determining the electric shock of the living body can be improved.

Description

Technical Field

[0001] This invention relates to the field of low-voltage power distribution network technology, and more specifically to a method, device, and storage medium for identifying biological electric shock to electrical equipment. Background Technology

[0002] Residual current protection devices are commonly used in low-voltage distribution networks to protect against electric shock. Current technologies rely on electric shock feature extraction methods to identify whether a living person has been electrocuted by equipment. These methods primarily include statistical features, approximate entropy, cyclic spectrum, and energy spectrum. However, these methods do not consider complex on-site conditions and are highly dependent on existing samples. When the type of electric shock or line parameters change, accurate identification of electric shock accidents becomes difficult. Therefore, current technologies suffer from low accuracy in determining electric shock in living individuals. Summary of the Invention

[0003] The purpose of this application is to provide a method, device, and storage medium for identifying biological electric shock in electrical equipment, in order to solve the problem of low accuracy in determining biological electric shock in the prior art.

[0004] To achieve the above objectives, a first aspect of this application provides a method for identifying bioelectric shock to electrical equipment, the method comprising: Acquire the total leakage current signal and the leakage current signal to ground of the electrical equipment within a preset period; Based on the amplitude of the total leakage current signal and the preset trigger amplitude threshold, determine whether the first electric shock trigger condition is met; Determine the phase difference between the total leakage current signal and the ground leakage current signal within a preset period to obtain the electric shock current signal within the preset period. Based on the electric shock current signal within a preset period, determine the first effective value of the electric shock current signal in the first preset sub-cycle within the preset period, the second effective value of the electric shock current signal in the second preset sub-cycle within the preset period, and the third effective value of the electric shock current signal in the third preset sub-cycle within the preset period. The first sub-cycle ratio and the second sub-cycle ratio are determined based on the effective values ​​of the first electric shock current signal, the second electric shock current signal, and the third electric shock current signal. Based on the ratio of the first sub-cycle and the ratio of the second sub-cycle, determine whether the second electric shock triggering condition is met; Based on the phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal, determine whether the third electric shock triggering condition is met; If the first, second, and third electric shock triggering conditions are met simultaneously, it is determined that the electrical equipment is experiencing electric shock to a living organism.

[0005] In this embodiment of the application, determining whether the first electric shock triggering condition is met based on the amplitude of the total leakage current signal and the preset trigger amplitude threshold includes: determining that the first electric shock triggering condition is met when the amplitude of the total leakage current signal is greater than or equal to the preset trigger amplitude threshold; and determining that the first electric shock triggering condition is not met when the amplitude of the total leakage current signal is less than the preset trigger amplitude threshold.

[0006] In this embodiment of the application, determining the first sub-cycle ratio and the second sub-cycle ratio based on the effective values ​​of the first, second, and third electric shock current signals includes: determining the first sub-cycle ratio based on the effective values ​​of the first and second electric shock current signals; and determining the second sub-cycle ratio based on the effective values ​​of the second and third electric shock current signals.

[0007] In this embodiment of the application, determining the first sub-cycle ratio based on the effective value of the first electric shock current signal and the effective value of the second electric shock current signal includes: determining the difference between the effective value of the second electric shock current signal and the effective value of the first electric shock current signal to obtain the difference in the effective value of the first electric shock current signal; and determining the ratio of the difference in the effective value of the first electric shock current signal and the effective value of the second electric shock current signal to obtain the first sub-cycle ratio.

[0008] In this embodiment of the application, determining the second sub-cycle ratio based on the effective value of the second electric shock current signal and the effective value of the third electric shock current signal includes: determining the difference between the effective value of the third electric shock current signal and the effective value of the second electric shock current signal to obtain the difference in the effective value of the second electric shock current signal; and determining the ratio between the difference in the effective value of the second electric shock current signal and the effective value of the third electric shock current signal to obtain the second sub-cycle ratio.

[0009] In this embodiment of the application, determining whether the second electric shock triggering condition is met based on the first sub-cycle ratio and the second sub-cycle ratio includes: determining that the second electric shock triggering condition is met when the first sub-cycle ratio is greater than or equal to the first preset sub-cycle ratio threshold and the second sub-cycle ratio is greater than or equal to the second preset sub-cycle ratio threshold.

[0010] In this embodiment of the application, determining whether the third electric shock triggering condition is met based on the phase difference between the three-phase voltage and the electric shock current signal of the electrical equipment includes: determining the phase difference between the A-phase voltage of the A-phase and the electric shock current signal of the three phases to obtain a first phase difference value; determining the phase difference between the B-phase voltage of the B-phase and the electric shock current signal of the three phases to obtain a second phase difference value; determining the phase difference between the C-phase voltage of the C-phase and the electric shock current signal of the three phases to obtain a third phase difference value; and determining that the third electric shock triggering condition is met when the first phase difference value is in a first preset phase difference value range, or the second phase difference value is in a second preset phase difference value range, or the third phase difference value is in a third preset phase difference value range.

[0011] In this embodiment of the application, the identification method further includes: filtering the total leakage current signal based on a filtering algorithm to obtain a filtered total leakage current signal.

[0012] A second aspect of this application provides a bioelectric shock identification device for electrical equipment, comprising: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the above-described bioelectric shock identification method for electrical equipment.

[0013] A third aspect of this application provides a machine-readable storage medium storing instructions that cause a machine to execute the aforementioned method for identifying bioelectric shock to electrical equipment.

[0014] The above technical solution acquires the total leakage current signal and the ground leakage current signal of the electrical equipment within a preset period. Based on the amplitude of the total leakage current signal and a preset trigger amplitude threshold, it determines whether the first electric shock trigger condition is met. The preset trigger amplitude threshold can be used for screening, quickly filtering out scenarios without electric shock risk and reducing computational load. The equal phase difference between the total leakage current signal and the ground leakage current signal within the preset period is determined to obtain the electric shock current signal within the preset period. This difference can be used to isolate the equipment's own leakage current, accurately locating any additional current that may be generated by electric shock, improving signal targeting. Based on the electric shock current signal within the preset period, the effective values ​​of the first, second, and third electric shock current signals for the first, second, and third preset sub-cycles within the preset period are determined. Focusing on the first three and a half cycles (the initial stage of electric shock), early current characteristic capture is achieved, laying the foundation for rapid judgment. By subtracting equipotential values ​​and calculating the effective value of sub-cycles, and combining this with the phase difference variation pattern, accurate classification of electric shock types can be achieved. Based on the effective values ​​of the first, second, and third electric shock current signals, the ratios of the first and second sub-cycles are determined. These ratios are then used to determine whether the second electric shock triggering condition is met, allowing for dual discrimination and reducing false positives. The phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal determines whether the third electric shock triggering condition is met. This triple discrimination, achieved through the phase of the three-phase voltage and the current phase of the electric shock signal, further minimizes false positives. When the first, second, and third electric shock triggering conditions are simultaneously met, it is determined that the electrical equipment contains a biological electric shock phenomenon. Finally, by superimposing these three conditions, multi-dimensional cross-validation is achieved, significantly improving the accuracy of electric shock identification, reducing missed or false positives, and thus enhancing the accuracy of determining biological electric shock.

[0015] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 The schematic diagram illustrates a flowchart of a method for identifying bioelectric shock to electrical equipment according to an embodiment of this application; Figure 2This illustration schematically shows the hardware design of a residual current protection device based on an electric shock identification algorithm according to an embodiment of this application; Figure 3 The illustration schematically shows the software design of a residual current protection device based on an electric shock identification algorithm according to an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0018] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0019] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0021] Figure 1 This illustration schematically shows a flowchart of a method for identifying bio-electric shock to electrical equipment according to an embodiment of this application. Figure 1As shown in the illustration, this application provides a method for identifying bio-electric shock in electrical equipment. Taking the application of this method to a processor as an example, the method may include the following steps: Step S101: Obtain the total leakage current signal and the leakage current signal to ground of the electrical equipment within a preset period; Step S102: Determine whether the first electric shock triggering condition is met based on the amplitude of the total leakage current signal and the preset trigger amplitude threshold. Step S103: Determine the phase difference between the total leakage current signal and the ground leakage current signal within the preset period, so as to obtain the electric shock current signal within the preset period. Step S104: Based on the electric shock current signal within the preset period, determine the first effective value of the electric shock current signal in the first preset sub-cycle within the preset period, the second effective value of the electric shock current signal in the second preset sub-cycle within the preset period, and the third effective value of the electric shock current signal in the third preset sub-cycle within the preset period. Step S105: Determine the first sub-cycle ratio and the second sub-cycle ratio based on the effective values ​​of the first electric shock current signal, the second electric shock current signal, and the third electric shock current signal. Step S106: Determine whether the second electric shock triggering condition is met based on the ratio of the first sub-cycle and the ratio of the second sub-cycle. Step S107: Determine whether the third electric shock triggering condition is met based on the phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal. Step S108: If the first electric shock triggering condition, the second electric shock triggering condition, and the third electric shock triggering condition are all met simultaneously, it is determined that there is a biological electric shock phenomenon in the electrical equipment.

[0022] It can be understood that the preset period is a pre-set period, which can be 1.5 periods. The preset trigger amplitude threshold is a pre-set amplitude threshold for triggering the electric shock mechanism, which can be 200mA. The preset sub-period is a pre-set sub-period, which can be 0.5 periods. The first electric shock trigger condition is the first trigger condition. The equal phase difference is the difference under the condition of equal phase. The effective value of the first electric shock current signal is the effective value of the electric shock current signal in the first half-cycle within the preset period. The effective value of the second electric shock current signal is the effective value of the electric shock current signal in the second half-cycle within the preset period. The effective value of the third electric shock current signal is the effective value of the electric shock current signal in the third half-cycle within the preset period. The first sub-period ratio and the second sub-period ratio are values ​​determined based on the effective values ​​of the first, second, and third electric shock current signals. The second electric shock trigger condition is the second trigger condition. The three-phase voltage phase is the voltage phase of the three-phase voltage. The electric shock current signal current phase is the current phase of the electric shock current signal. The third electric shock trigger condition is the third trigger condition.

[0023] Specifically, the processor acquires the total leakage current signal and the ground leakage current signal of the electrical equipment within a preset period, and determines whether the first electric shock triggering condition is met based on the amplitude of the total leakage current signal and a preset trigger amplitude threshold. The processor determines the difference between the total leakage current signal and the ground leakage current signal within the preset period to obtain the electric shock current signal for the preset period. Based on the electric shock current signal of the preset period, it determines the effective values ​​of the electric shock current signals for the first three and a half cycles within the preset period. Based on the effective values ​​of the first, second, and third electric shock current signals, it determines the first sub-cycle ratio and the second sub-cycle ratio, and determines whether the second electric shock triggering condition is met based on the first and second sub-cycle ratios. The processor determines whether the third electric shock triggering condition is met based on the three-phase voltage phase of the three-phase voltage of the device under test and the current phase of the electric shock current signal. If the first, second, and third electric shock triggering conditions are met simultaneously, the processor determines that an electric shock to a living organism has occurred.

[0024] The above technical solution acquires the total leakage current signal and the ground leakage current signal of the electrical equipment within a preset period. Based on the amplitude of the total leakage current signal and a preset trigger amplitude threshold, it determines whether the first electric shock trigger condition is met. The preset trigger amplitude threshold can be used for screening, quickly filtering out scenarios without electric shock risk and reducing computational load. The equal phase difference between the total leakage current signal and the ground leakage current signal within the preset period is determined to obtain the electric shock current signal within the preset period. This difference can be used to isolate the equipment's own leakage current, accurately locating any additional current that may be generated by electric shock, improving signal targeting. Based on the electric shock current signal within the preset period, the effective values ​​of the first, second, and third electric shock current signals for the first, second, and third preset sub-cycles within the preset period are determined. Focusing on the first three and a half cycles (the initial stage of electric shock), early current characteristic capture is achieved, laying the foundation for rapid judgment. By subtracting equipotential values ​​and calculating the effective value of sub-cycles, and combining this with the phase difference variation pattern, accurate classification of electric shock types can be achieved. Based on the effective values ​​of the first, second, and third electric shock current signals, the ratios of the first and second sub-cycles are determined. These ratios are then used to determine whether the second electric shock triggering condition is met, allowing for dual discrimination and reducing false positives. The phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal determines whether the third electric shock triggering condition is met. This triple discrimination, achieved through the phase of the three-phase voltage and the current phase of the electric shock signal, further minimizes false positives. When the first, second, and third electric shock triggering conditions are simultaneously met, it is determined that the electrical equipment contains a biological electric shock phenomenon. Finally, by superimposing these three conditions, multi-dimensional cross-validation is achieved, significantly improving the accuracy of electric shock identification, reducing missed or false positives, and thus enhancing the accuracy of determining biological electric shock.

[0025] In one embodiment, determining whether the first electric shock triggering condition is met based on the amplitude of the total leakage current signal and a preset trigger amplitude threshold includes: determining that the first electric shock triggering condition is met when the amplitude of the total leakage current signal is greater than or equal to the preset trigger amplitude threshold; and determining that the first electric shock triggering condition is not met when the amplitude of the total leakage current signal is less than the preset trigger amplitude threshold.

[0026] Specifically, the processor determines whether the amplitude of the total leakage current signal is greater than or equal to the preset trigger amplitude threshold to determine whether the first electric shock trigger condition is met. The preset trigger amplitude threshold can be used to screen and quickly filter out scenarios with no risk of electric shock, reducing the amount of computation.

[0027] In one embodiment, determining the first sub-cycle ratio and the second sub-cycle ratio based on the effective values ​​of the first, second, and third electric shock current signals includes: determining the first sub-cycle ratio based on the effective values ​​of the first and second electric shock current signals; and determining the second sub-cycle ratio based on the effective values ​​of the second and third electric shock current signals.

[0028] Specifically, the processor determines the first sub-cycle ratio based on the effective values ​​of the first and second electric shock current signals, and determines the second sub-cycle ratio based on the effective values ​​of the second and third electric shock current signals, thus providing a basis for the subsequent determination of the second electric shock triggering condition.

[0029] In one embodiment, determining the first sub-cycle ratio based on the effective value of the first electric shock current signal and the effective value of the second electric shock current signal includes: determining the difference between the effective value of the second electric shock current signal and the effective value of the first electric shock current signal to obtain the effective value difference of the first electric shock current signal; and determining the ratio of the effective value difference of the first electric shock current signal and the effective value of the second electric shock current signal to obtain the first sub-cycle ratio.

[0030] It can be understood that the effective value difference of the first electric shock current signal is the difference between the effective value of the second electric shock current signal and the effective value of the first electric shock current signal.

[0031] Specifically, the processor determines the difference between the effective value of the second electric shock current signal and the effective value of the first electric shock current signal to obtain the effective value difference of the first electric shock current signal, and then determines the ratio of the effective value difference of the first electric shock current signal and the effective value of the second electric shock current signal to obtain the first sub-cycle ratio. This application focuses on the relative change amplitude of adjacent sub-cycles, and amplifies the specific fluctuation pattern of current as a biological body experiences electric shock with changes in human body impedance through the first sub-cycle ratio, which is clearly distinguished from the low fluctuation of stable leakage current in equipment, thereby improving the specificity of electric shock identification.

[0032] In one embodiment, determining the second sub-cycle ratio based on the effective values ​​of the second and third electric shock current signals includes: determining the difference between the effective values ​​of the third and second electric shock current signals to obtain the difference in the effective values ​​of the second electric shock current signals; and determining the ratio between the difference in the effective values ​​of the second and third electric shock current signals to obtain the second sub-cycle ratio.

[0033] It can be understood that the effective value difference of the second electric shock current signal is the difference between the effective value of the third electric shock current signal and the effective value of the second electric shock current signal.

[0034] Specifically, the processor determines the difference between the effective value of the third electric shock current signal and the effective value of the second electric shock current signal to obtain the effective value difference of the second electric shock current signal. Then, it determines the ratio of the effective value difference of the second electric shock current signal to the effective value of the third electric shock current signal to obtain the second sub-cycle ratio. This application focuses on the relative change amplitude of adjacent sub-cycles. By amplifying the specific fluctuation pattern of current as the human body's impedance changes during electric shock through the second sub-cycle ratio, it clearly distinguishes it from the low fluctuation of stable leakage current in equipment, thus improving the specificity of electric shock identification.

[0035] In one embodiment, determining whether the second electric shock triggering condition is met based on the first sub-cycle ratio and the second sub-cycle ratio includes: determining that the second electric shock triggering condition is met when the first sub-cycle ratio is greater than or equal to a first preset sub-cycle ratio threshold and the second sub-cycle ratio is greater than or equal to a second preset sub-cycle ratio threshold.

[0036] It can be understood that the first preset sub-cycle ratio threshold is a pre-set threshold for the first sub-cycle ratio, which can be 0.3. The first preset sub-cycle ratio threshold is also a pre-set threshold for the second sub-cycle ratio, which can be 0.1.

[0037] Specifically, the processor can determine that the second electric shock triggering condition is met when the ratio of the first sub-cycle is greater than or equal to 0.3 and the ratio of the second sub-cycle is greater than or equal to 0.1. This application transforms the dynamic waveform characteristics of the electric shock current into a calculable quantitative index, providing accurate and interference-resistant characteristic basis for triggering condition judgment, and further improving the accuracy of electric shock identification.

[0038] In one embodiment, determining whether a third electric shock triggering condition is met based on the phase difference between the three-phase voltage and the electric shock current signal of the electrical equipment includes: determining the phase difference between the A-phase voltage of phase A and the electric shock current signal of the three phases to obtain a first phase difference value; determining the phase difference between the B-phase voltage of phase B and the electric shock current signal of the three phases to obtain a second phase difference value; determining the phase difference between the C-phase voltage of phase C and the electric shock current signal of the three phases to obtain a third phase difference value; and determining that the third electric shock triggering condition is met when the first phase difference value is within a first preset phase difference value range, or the second phase difference value is within a second preset phase difference value range, or the third phase difference value is within a third preset phase difference value range.

[0039] It can be understood that the first phase difference is the difference between the phase of phase A voltage and the phase of the electric shock current signal current. The second phase difference is the difference between the phase of phase B voltage and the phase of the electric shock current signal current. The third phase difference is the difference between the phase of phase C voltage and the phase of the electric shock current signal current. The first preset phase difference range is a pre-set range regarding the first phase difference, which can be from 13° to 90°. The second preset phase difference range is a pre-set range regarding the second phase difference, which can be from 133° to 233°. The third preset phase difference range is a pre-set range regarding the third phase difference, which can be from 253° to 343°.

[0040] Specifically, the processor determines that the third electric shock triggering condition is met when the first phase difference is in the range of 13° to 90°, the second phase difference is in the range of 133° to 233°, or the third phase difference is in the range of 253° to 343°. The difference between the three-phase voltage phase and the electric shock current signal phase can be used as a basis to determine whether the third electric shock triggering condition is met, which can further improve the accuracy of determining whether an electric shock has occurred.

[0041] In one embodiment, the identification method further includes: filtering the total leakage current signal based on a filtering algorithm to obtain a filtered total leakage current signal.

[0042] Specifically, the processor filters the total leakage current signal based on a filtering algorithm to obtain a filtered total leakage current signal. The filtering method can be a wavelet filtering algorithm. This application uses a wavelet filtering algorithm to extract the fundamental component, which can eliminate harmonic interference and ensure the integrity of the electric shock waveform. A specific embodiment of this application provides a method for identifying biological electric shock to electrical equipment, the specific steps of which are as follows: This patent proposes a method for identifying electric shock based on the characteristics of biological electric shock. This method uses zero-crossing as a criterion. First, it samples the residual current of the circuit for 1.5 cycles as the basic residual current. Then, it samples the total residual current for 1.5 cycles through a sliding window. Next, it uses a wavelet filtering algorithm to obtain the fundamental waveform of the total residual current and the basic residual current. Finally, it subtracts the filtered total residual current of 1.5 cycles from the basic residual current of 1.5 cycles at the same potential, thus canceling out the basic residual current waveform and obtaining the fundamental waveform of the biological electric shock current. Finally, it calculates the effective value and phase difference of the sub-cycles of the fundamental waveform. Based on the changing patterns of the ratio of the effective values ​​of the electric shock cycles and the phase difference, the type of electric shock can be accurately identified. Finally, based on the proposed identification algorithm, a prototype of a separate residual current protection device was designed.

[0043] S1: Input total residual current Is(t); S1: Wavelet filtering In(t) is applied to the total residual current. The total residual current typically contains the fundamental current and integer harmonic currents. These harmonics affect the identification of the electric shock current characteristics; therefore, a filtering algorithm is needed to remove the harmonic currents to obtain the fundamental current of the total residual current. Wavelet thresholding has the advantages of simple implementation and fast computation speed, and can meet various filtering requirements such as low-pass, high-pass, notch filtering, and random noise removal, and is widely used in time-varying nonlinear signal processing. Therefore, this patent uses wavelet thresholding for filtering.

[0044] Wavelet thresholding filtering involves three steps: decomposition, threshold selection and quantization of high-frequency coefficients, and reconstruction. Selecting an appropriate wavelet, determining the optimal number of decomposition levels, and choosing a suitable threshold are crucial for achieving good signal filtering performance. The Mallat algorithm is highly efficient and can significantly reduce computational complexity. The decomposition process of the Mallat algorithm is as follows:

[0045] Where j is the decomposition scale, cj+1 and dj+1 are the scale signal and detail signal at the (j+1)th scale, respectively. In the initial stage of scale decomposition, c0 is generally approximated by the original discrete signal. H is a low-pass filter, and G is a high-pass filter. D0 represents even decimation. The signal reconstruction formula is:

[0046] In the formula, and These are the dual operators of H and G, respectively. Z0 is the zero-padding interpolation operator, and R0 is the reconstruction operator.

[0047] The low-pass and high-pass filters in the Mallat algorithm can be calculated using the following formula:

[0048] Here, h and g are the time-domain response functions of H and G, respectively, and H and G remain unchanged throughout the multiresolution analysis. and The scaling function and wavelet function satisfy the two-scale difference equation, i.e.

[0049] The selection of the threshold function is key to the performance of wavelet thresholding algorithms. Adaptive wavelet thresholding can achieve filtering better than hard thresholding and soft thresholding.

[0050] S3: Determine the amplitude of the total residual current. If the amplitude of the total residual current Iref ≥ 200mA, the residual current protection device will activate.

[0051] S4: Establish a basic residual current database. When Is(i-1)*Is(i)≤0 and Is(i+1)*Is(i)≥0, the first 1.5 complete cycles are sampled as the basic residual current database Ic(t).

[0052] S5: Extraction of bio-electric shock current. Let the filtered residual current over 1.5 cycles be Ic(j). Then, by subtracting the real-time sampled, filtered total residual current Is(j) over 1.5 cycles from the residual current Ic(j) in phase, we can obtain the electric shock current Ih(j):

[0053] In the formula, j = 1, 2, ..., 1.5N, and N is the sampling period.

[0054] S6: Calculation of half-wave RMS value and phase difference. The RMS value of the AC shock current signal is:

[0055] Among them, X rms is the effective value of the measured signal, squ() represents taking the square root, x[n] is the sampled signal, and N is the sampling quantity in one period.

[0056] The effective values ​​of the first three half-waves of the electric shock current can be expressed as:

[0057] The ratio of the second half-wave to the first half-wave is: :

[0058] The ratio of the third half-wave to the second half-wave is: :

[0059] Animal residual current half-wave and Ratio Recommendation ≥30%, ≥10%.

[0060] Taking phase A voltage as the reference phase, let phase A voltage and electric shock current be:

[0061]

[0062] The difference :

[0063] It is recommended that an animal be considered to have been electrocuted when the phase difference is ≥13°.

[0064] Based on the above analysis, it can be seen that the impedance of tree branches is resistive, while the impedance of animal bodies is resistive-capacitive, and purely capacitive. The phase angle is 90°. When the fault occurs in a different phase sequence, the phase difference of the three phases A, B, and C should be considered as 120°.

[0065] S7: Biological Electrocution Identification. The protection principle proposed in this patent, based on the characteristics of biological electrocution current, is as follows:

[0066]

[0067] In the formula: I ref The operating current threshold set based on the basic residual current is recommended to be 200mA to ensure power supply reliability, taking into account the actual operating conditions on site. S The function is used to sample the total residual current amplitude in real time. When the function value is 1, a fault occurs and the separate residual current protection device operates. When the function value is 0, no fault occurs and the separate residual current protection device does not operate.

[0068] Figure 2 This illustration schematically depicts the hardware design of a residual current protection device based on an electric shock identification algorithm according to an embodiment of this application; the hardware design of a separate residual current protector is as follows. Figure 2 As shown, it mainly includes a processor, AD sampling, and a trip unit. The residual current signal flowing through the current transformer is collected by the residual current transformer. The controller converts the signal into a voltage signal, then filters and amplifies it. The voltage signal is then sampled by a high-speed AD converter and converted into a digital signal. The residual current waveform is then restored by a high-performance processor. After identification algorithm, it is determined whether the basic residual current and electric shock current are in a fault state. If a fault state is found, a signal is immediately sent to the trip unit to execute the trip operation.

[0069] Figure 3 This illustration schematically depicts the software design of a residual current protection device based on an electric shock identification algorithm according to an embodiment of this application. The software design of the discrete residual current protector mainly includes algorithms for basic residual current determination and determination of the effective value and phase of the sliding half-wave, such as... Figure 3 As shown, the electrical signal is first acquired through AD sampling, and then three processes are performed: RMS value calculation, current extraction through sliding window, and voltage-current phase difference calculation. Next, three detection steps are performed: normal residual current judgment, half-wave RMS value judgment, and phase difference judgment. When the results of these three judgments are met simultaneously, a fault operation is triggered.

[0070] In one embodiment, this application provides a biological electric shock identification device for electrical equipment, comprising: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the above-described biological electric shock identification method for electrical equipment.

[0071] In one embodiment, this application provides a machine-readable storage medium storing instructions that cause a machine to execute the above-described method for identifying bioelectric shock to electrical equipment.

[0072] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0073] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for identifying biological electric shock to electrical equipment, characterized in that, The identification method includes: Acquire the total leakage current signal and the leakage current signal to ground of the electrical equipment within a preset period; Based on the amplitude of the total leakage current signal and the preset trigger amplitude threshold, determine whether the first electric shock trigger condition is met; The phase difference between the total leakage current signal and the ground leakage current signal within the preset period is determined to obtain the electric shock current signal within the preset period. Based on the electric shock current signal within the preset period, determine the first effective value of the electric shock current signal in the first preset sub-cycle within the preset period, the second effective value of the electric shock current signal in the second preset sub-cycle within the preset period, and the third effective value of the electric shock current signal in the third preset sub-cycle within the preset period. The first sub-cycle ratio and the second sub-cycle ratio are determined based on the effective values ​​of the first electric shock current signal, the second electric shock current signal, and the third electric shock current signal. Based on the ratio of the first sub-cycle and the ratio of the second sub-cycle, determine whether the second electric shock triggering condition is met; Based on the phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal, it is determined whether the third electric shock triggering condition is met; If the first electric shock triggering condition, the second electric shock triggering condition, and the third electric shock triggering condition are all met simultaneously, it is determined that the electrical equipment is experiencing electric shock to a living organism.

2. The identification method according to claim 1, characterized in that, The step of determining whether the first electric shock triggering condition is met based on the amplitude of the total leakage current signal and the preset trigger amplitude threshold includes: If the amplitude of the total leakage current signal is greater than or equal to the preset trigger amplitude threshold, it is determined that the first electric shock trigger condition is met. If the amplitude of the total leakage current signal is less than the preset trigger amplitude threshold, it is determined that the first electric shock trigger condition is not met.

3. The identification method according to claim 1, characterized in that, The step of determining the first sub-cycle ratio and the second sub-cycle ratio based on the effective values ​​of the first, second, and third electric shock current signals includes: The first sub-cycle ratio is determined based on the effective values ​​of the first and second electric shock current signals. The second sub-cycle ratio is determined based on the effective values ​​of the second and third electric shock current signals.

4. The identification method according to claim 3, characterized in that, The step of determining the first sub-cycle ratio based on the effective values ​​of the first and second electric shock current signals includes: Determine the difference between the effective value of the second electric shock current signal and the effective value of the first electric shock current signal to obtain the effective value difference of the first electric shock current signal; The ratio of the effective value difference of the first electric shock current signal to the effective value of the second electric shock current signal is determined to obtain the first sub-cycle ratio.

5. The identification method according to claim 3, characterized in that, The step of determining the second sub-cycle ratio based on the effective value of the second electric shock current signal and the effective value of the third electric shock current signal includes: The difference between the effective value of the third electric shock current signal and the effective value of the second electric shock current signal is determined to obtain the effective value difference of the second electric shock current signal; The ratio of the effective value difference of the second electric shock current signal to the effective value of the third electric shock current signal is determined to obtain the second sub-cycle ratio.

6. The identification method according to claim 1, characterized in that, The step of determining whether the second electric shock triggering condition is met based on the first sub-cycle ratio and the second sub-cycle ratio includes: If the first sub-cycle ratio is greater than or equal to the first preset sub-cycle ratio threshold, and the second sub-cycle ratio is greater than or equal to the second preset sub-cycle ratio threshold, it is determined that the second electric shock triggering condition is met.

7. The identification method according to claim 1, characterized in that, The step of determining whether the third electric shock triggering condition is met based on the phase difference between the three-phase voltage of the electrical equipment and the electric shock current signal includes: Determine the phase difference between phase A voltage of phase A in the three phases and the electric shock current signal to obtain a first phase difference value; Determine the phase difference between the phase B voltage of phase B in the three phases and the electric shock current signal to obtain a second phase difference value; Determine the phase difference between the C-phase voltage of the C-phase in the three phases and the electric shock current signal to obtain a third phase difference value; If the first phase difference is within a first preset phase difference range, or the second phase difference is within a second preset phase difference range, or the third phase difference is within a third preset phase difference range, then the third electric shock triggering condition is determined to be met.

8. The identification method according to claim 1, characterized in that, The identification method further includes: The total leakage current signal is filtered based on a filtering algorithm to obtain a filtered total leakage current signal.

9. A bioelectric shock identification device for electrical equipment, characterized in that, include: The memory is configured to store instructions; as well as A processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the method for identifying bioelectric shock to an electrical device according to any one of claims 1 to 8.

10. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the method for identifying bioelectric shock to electrical equipment according to any one of claims 1 to 8.

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