A method and apparatus for detecting electromagnetic interference of a power harness and related components

Abstract

This invention discloses a method, device, and related components for detecting electromagnetic interference (EMI) in power wiring harnesses. The method includes: real-time acquisition of electromagnetic signals from the power wiring harness; preprocessing the electromagnetic signals to generate digital signals; performing interference intensity analysis on the digital signals to obtain the EMI intensity; determining whether the EMI intensity reaches a predetermined threshold; and if the EMI intensity reaches the predetermined threshold, determining that the power wiring harness exhibits EMI. This invention, by real-time acquisition of electromagnetic signals from the power wiring harness, can quickly detect abnormal states of the power wiring harness and issue timely alarms, preventing equipment downtime or damage due to power wiring harness failures. It can also accurately assess the EMI intensity of the power wiring harness to external signals, providing a basis for the electromagnetic compatibility design of equipment.

Description

Technical Field

[0001] This invention relates to the field of wire harness technology, and in particular to an electromagnetic interference detection method, device, and related components for power wire harnesses. Background Technology

[0002] In modern industrial and electronic equipment, power harnesses, as core components for power transmission, are widely used in various automation systems, electric drive devices, and industrial equipment. However, power harnesses are prone to failure during operation due to faults such as short circuits, open circuits, and poor contact. This not only affects the normal operation of the equipment but may also cause serious electromagnetic interference (EMI) problems.

[0003] Electromagnetic interference (EMI) refers to the inability of equipment or systems to function properly due to interference from external electromagnetic signals while operating in an electromagnetic environment, or the interference caused by electromagnetic signals generated by the equipment or systems themselves. In complex electromagnetic environments such as industrial production sites and data centers, the high-frequency harmonics, transient voltage fluctuations, and radiated electromagnetic fields generated by power wiring harnesses during operation can cause significant interference to surrounding sensitive equipment.

[0004] Traditional testing methods typically rely on manual inspections or simple current and voltage measurements, which have the following limitations:

[0005] 1. Manual inspections are difficult to conduct continuous monitoring and cannot capture transient faults or dynamically changing electromagnetic interference;

[0006] 2. Current and voltage measurements only reflect the state of electrical energy transmission and cannot directly quantify the electromagnetic interference intensity of the power harness. Summary of the Invention

[0007] The purpose of this invention is to provide an electromagnetic interference detection method, device, and related components for power wiring harnesses, aiming to solve the problems that existing electromagnetic interference detection methods cannot capture transient faults or dynamically changing electromagnetic interference.

[0008] In a first aspect, embodiments of the present invention provide an electromagnetic interference detection method for power wiring harnesses, comprising:

[0009] Real-time acquisition of electromagnetic signals from power wiring harnesses;

[0010] The electromagnetic signal is preprocessed to generate a digital signal;

[0011] The electromagnetic interference intensity is obtained by performing interference intensity analysis on the digital signal.

[0012] Determine whether the electromagnetic interference intensity reaches a predetermined threshold;

[0013] If the electromagnetic interference intensity reaches a predetermined threshold, it is determined that the power harness is subject to electromagnetic interference.

[0014] Secondly, embodiments of the present invention provide an electromagnetic interference detection device for power wiring harnesses, comprising:

[0015] The acquisition unit is used to acquire electromagnetic signals of the power harness in real time.

[0016] The preprocessing unit is used to preprocess the electromagnetic signal to generate a digital signal;

[0017] The analysis unit is used to perform interference intensity analysis on the digital signal to obtain the electromagnetic interference intensity;

[0018] The judgment unit is used to determine whether the electromagnetic interference intensity reaches a predetermined threshold.

[0019] The determination unit is used to determine that the power harness has electromagnetic interference if the electromagnetic interference intensity reaches a predetermined threshold.

[0020] Thirdly, embodiments of the present invention provide a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the electromagnetic interference detection method for power harnesses described in the first aspect.

[0021] Fourthly, embodiments of the present invention also provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the electromagnetic interference detection method for power harnesses described in the first aspect.

[0022] This invention discloses a method, device, and related components for detecting electromagnetic interference (EMI) in power wiring harnesses. The method includes: real-time acquisition of electromagnetic signals from the power wiring harness; preprocessing the electromagnetic signals to generate digital signals; performing interference intensity analysis on the digital signals to obtain the EMI intensity; determining whether the EMI intensity reaches a predetermined threshold; and determining that the power wiring harness exhibits EMI if the EMI intensity reaches the predetermined threshold. This invention, by real-time acquisition of electromagnetic signals from the power wiring harness, can quickly detect abnormal states of the power wiring harness and issue timely alarms, preventing equipment downtime or damage due to power wiring harness failures. It can also accurately assess the EMI intensity of the power wiring harness to external signals, providing a basis for the electromagnetic compatibility design of equipment. This invention also provides an EMI detection device for power wiring harnesses, a computer-readable storage medium, and a computer device, which have the above-mentioned beneficial effects and will not be elaborated further here. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the electromagnetic interference detection method for power wiring harnesses.

[0025] Figure 2 This is a schematic block diagram of an electromagnetic interference detection device for power wiring harnesses. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more of its features, integrals, steps, operations, elements, components and / or collections thereof.

[0028] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0030] Please see Figure 1 This embodiment provides an electromagnetic interference detection method for power wiring harnesses, including:

[0031] S101: Real-time acquisition of electromagnetic signals from power harness;

[0032] This embodiment achieves real-time monitoring of the operating status of the power wiring harness by deploying a magnetic induction electromagnetic signal acquisition sensor. The sensor adopts a non-contact design, closely fitting the surface of the power wiring harness, and acquires electromagnetic signals in real time by detecting changes in the electromagnetic field around the harness (including magnetic field strength, frequency distribution, etc.).

[0033] S102: Preprocess the electromagnetic signal to generate a digital signal;

[0034] Specifically, the acquired electromagnetic signals are filtered (to remove environmental noise), amplified (to enhance weak signals), and converted from analog to digital (to digital signals) by the signal processing unit, ensuring high fidelity and low latency of the signal.

[0035] More specifically, a low-pass filter removes high-frequency noise above the target frequency band from the electromagnetic signal while preserving the 50Hz fundamental frequency and harmonic components (such as the 5th and 7th harmonics). To address the common 50Hz power frequency interference in industrial scenarios, a notch filter is further introduced to precisely suppress interference signals at 50Hz and its integer multiples. Furthermore, filter parameters can be dynamically adjusted (e.g., increasing the bandwidth to 500kHz) to capture rapid changes in higher harmonics.

[0036] The filtered electromagnetic signal is amplified by an adaptive gain control circuit. This circuit dynamically adjusts the amplification factor (e.g., adjustable from 0-60dB) according to the signal amplitude, ensuring that both weak signals (such as local electromagnetic fluctuations caused by poor contact) and strong signals (such as transient interference during motor startup) are accurately captured. For example, when the amplitude of the 5th or 7th harmonic is detected to exceed a preset threshold, the system automatically reduces the gain to avoid signal saturation distortion.

[0037] The amplified analog signal is converted into a digital signal by a 24-bit high-precision analog-to-digital converter (ADC), with a sampling rate set to 2 MSps to meet the sampling requirements of higher harmonics. The digital signal is stored in floating-point format and timestamped to ensure timing consistency in subsequent data analysis.

[0038] In some embodiments, the LMS algorithm is used to adjust the filter weights in real time. The filter coefficients are updated by the iterative formula w(n+1)=w(n)+μ*e(n)*x(n), where w(n) is the current weight vector, μ is the step size parameter, e(n) is the error signal (the difference between the expected signal and the filter output), and x(n) is the input signal vector.

[0039] For 50Hz power frequency interference, a notch filter (IIR notch filter) is used to provide a deep valley at 50Hz to attenuate the interference energy.

[0040] For high-frequency impulse noise, the fast convergence characteristic of the LMS algorithm is used to dynamically suppress transient noise, and the convergence speed and stability are balanced by adjusting the step size parameter μ.

[0041] S103: Perform interference intensity analysis on the digital signal to obtain the electromagnetic interference intensity;

[0042] Specifically, interference intensity analysis of digital signals yields electromagnetic interference intensity, including:

[0043] The Fourier transform algorithm is used to extract the fundamental component and its higher harmonic components of a digital signal, and the energy values ​​of the fundamental component and each higher harmonic component are calculated.

[0044] The electromagnetic interference intensity is calculated based on the energy values ​​of the fundamental component and each higher harmonic component.

[0045] This embodiment converts the time-domain electromagnetic signal into a frequency-domain signal using Fourier transform, which can clearly separate the fundamental component (such as 50Hz power frequency) from higher harmonic components (such as the 5th and 7th harmonics), avoiding the interference and confusion caused by signal superposition in traditional time-domain analysis. Simultaneously, by calculating the energy values ​​of the fundamental and harmonic components, the absolute intensity of electromagnetic interference can be quantified, avoiding the limitations of traditional methods that rely solely on voltage or current.

[0046] In this embodiment, the energy value of the fundamental component is calculated as follows:

[0047] Obtain the equivalent impedance of the power harness;

[0048] The fundamental component is extracted from the digital signal using a sliding window Fourier transform algorithm with a first predetermined step size, and the instantaneous voltage value of the fundamental component is calculated.

[0049] The energy value of the fundamental component is calculated based on the equivalent impedance, the instantaneous voltage value of the fundamental component, and the first predetermined step size, according to the following formula:

[0050]

[0051] Among them, E 基波 V represents the energy value of the fundamental component; 基波 (t) represents the instantaneous voltage value of the fundamental component; R represents the equivalent impedance; t1 and t2 represent the start and end times of the first predetermined step, respectively.

[0052] Furthermore, obtaining the equivalent impedance of the power harness includes: deploying impedance measurement units at both the input and output ends of the power harness; injecting a test signal of known frequency (such as a 50Hz fundamental wave or a 1kHz low-frequency signal) and measuring the amplitude and phase difference of the voltage and current; and calculating the equivalent impedance R. For example, when the test signal is a sine wave, the equivalent impedance can be calculated using the formula R = V / I, where V and I are the root mean square values ​​of the voltage and current of the test signal, respectively.

[0053] However, the equivalent impedance of the power harness can fluctuate due to temperature, load changes, or cable aging. For example, when a variable frequency motor starts, the cable impedance may decrease due to a sudden increase in current causing a rise in temperature (e.g., from 0.5Ω to 0.3Ω). This embodiment ensures that the equivalent impedance value always reflects the current state by periodically triggering impedance measurements (e.g., every 5 minutes) or actively triggering measurements during load surge events (e.g., equipment startup or shutdown).

[0054] In some embodiments, extracting the fundamental component from the digital signal using a sliding window Fourier transform algorithm with a first predetermined step size and calculating the instantaneous voltage value of the fundamental component includes:

[0055] The acquired digital signal is divided into continuously overlapping sliding windows (e.g., window length of 20ms and step size of 10ms), and a Fast Fourier Transform (FFT) is performed on the digital signal within each sliding window. For example, in a device startup scenario, the sliding window moves dynamically in 10ms steps to ensure that rapid changes in the fundamental amplitude are captured (e.g., the fundamental amplitude rises sharply within tens of milliseconds when a variable frequency motor starts).

[0056] Next, within each sliding window, the frequency domain energy peak of the fundamental component at 50Hz / 60Hz is located by analyzing the spectral characteristics of the signal using FFT. For example, when the power harness is operating in a 50Hz power grid, the maximum amplitude at 50Hz is identified in the spectrum, and the fundamental component of the corresponding time domain signal is extracted.

[0057] Based on the fundamental frequency spectrum data within the sliding window, the time-domain waveform of the fundamental component is reconstructed using inverse Fourier transform (IFFT), and the instantaneous voltage value at the center of each sliding window is extracted. For example, in a 10ms step window, if the fundamental amplitude is 220V, the instantaneous voltage value V at the center of that sliding window (e.g., at the 5th ms) is calculated. 基波 (t)=220*sin(2π*50*t).

[0058] In this embodiment, the energy values ​​of higher harmonic components are calculated as follows:

[0059] Obtain the equivalent impedance of the power harness;

[0060] The sliding window Fourier transform algorithm is used to extract higher harmonic components from the digital signal with a second predetermined step size, and the instantaneous voltage value of the higher harmonic components is calculated.

[0061] The energy value of the higher harmonic components is calculated based on the equivalent impedance, the instantaneous voltage value of the higher harmonic components, and the second predetermined step size, according to the following formula:

[0062]

[0063] Among them, E n V represents the energy value of higher harmonic components. n (t) represents the instantaneous voltage value of the higher harmonic components; R represents the equivalent impedance; t3 and t4 represent the start and end times of the second predetermined step, respectively.

[0064] Furthermore, the sliding window Fourier transform algorithm is used to extract higher harmonic components from the digital signal according to a second predetermined step size, and the instantaneous voltage values ​​of the higher harmonic components are calculated, including:

[0065] The acquired digital signal is divided into consecutively overlapping sliding windows, and a Fast Fourier Transform (FFT) is performed on the digital signal within each sliding window.

[0066] Next, within each sliding window, the frequency domain energy peaks of the 5th, 7th, and other higher harmonic components are located by analyzing the spectral characteristics of the signal using FFT. For example, when the power harness is operating in a 50Hz power grid, the system identifies the maximum amplitude values ​​at 250Hz (5th harmonic) and 350Hz (7th harmonic) in the spectrum diagram and extracts the corresponding higher harmonic components of the time domain signal.

[0067] Based on the high-order harmonic spectrum data within the sliding window, the time-domain waveforms of the high-order harmonic components are reconstructed using inverse Fourier transform (IFFT), and the instantaneous voltage values ​​at the center of each window are extracted.

[0068] In some embodiments, the operating environment parameters (such as temperature T and humidity H) of the power harness are collected in real time by devices such as temperature sensors and humidity sensors.

[0069] The collected environmental parameters are then transmitted to the signal processing unit for preprocessing (such as filtering and normalization).

[0070] Furthermore, based on the temperature-impedance relationship of the power harness material (e.g., the resistivity of a metallic conductor ρ(T) = ρ0[1 + α(T - T0)], where ρ0 is the resistivity at the reference temperature T0 and α is the temperature coefficient) and the influence of humidity on insulation impedance (e.g., Rinsulation(H) = R0 * e -kHWhere R0 is the insulation resistance under the reference humidity and k is the humidity coefficient, a correlation model between environmental parameters and equivalent impedance is constructed.

[0071] Then, historical data is used to train regression models (such as random forests and support vector regression) or neural network models to predict the combined impact of environmental parameters on equivalent impedance.

[0072] Subsequently, based on the real-time environmental parameters temperature T and humidity H, the corrected equivalent impedance Rcorrected is calculated through a dynamic correction model. The formula is Rcorrected=Rinitial*f(T,H), where Rinitial is the uncorrected equivalent impedance and f(T,H) is the environmental parameter correction function.

[0073] The implementation methods of the correction function f(T, H) include:

[0074] If the environmental impact is small, the linear model f(T,H)=aT+bH+c is adopted, where a, b, and c are preset coefficients;

[0075] If the environmental impact is significant, a polynomial fitting or exponential model f(T, H) = d*e is used. fT +h*ln(H+r), where d, f, h and r are the fitting parameters;

[0076] The corrected equivalent impedance Rcorrected is substituted into the calculation formulas for the energy values ​​of the fundamental component and the higher harmonic components to dynamically adjust the energy values ​​of the fundamental component and the higher harmonic components, thereby eliminating errors caused by environmental fluctuations.

[0077] After calculating the energy values ​​of the fundamental component and each higher harmonic component, the electromagnetic interference intensity is then calculated based on these values, specifically including:

[0078] Calculate the electromagnetic interference intensity using the following formula:

[0079]

[0080] Among them, E EMI Indicates electromagnetic interference intensity; w0 represents fundamental frequency weight; E 基波 Indicates the energy value of the fundamental component; w n E represents the weight of the nth higher harmonic component; n This represents the energy value of the nth higher harmonic component; N represents the total number of higher harmonic components.

[0081] Furthermore, after calculating the electromagnetic interference intensity according to the following formula, it includes:

[0082] Obtain the operating status of the device;

[0083] If the equipment is in a startup or load change condition, increase the weighting coefficient of the higher harmonic components;

[0084] If the equipment is in steady-state operation, reduce the weighting coefficient of higher harmonic components and increase the weighting of the fundamental frequency.

[0085] During equipment startup or sudden load changes, the weighting coefficients of higher harmonic components (such as the 5th and 7th harmonics) are automatically increased, while the weighting of the fundamental frequency is decreased. For example, when the startup of a variable frequency motor is detected, the amplitude of the 5th harmonic can reach 70% of the fundamental frequency, which will be increased from the default value of 0.2 to 0.5, while the weighting of the fundamental frequency will decrease from 0.6 to 0.3. This adjustment highlights the significant impact of transient higher harmonics on electromagnetic interference and avoids underestimation of interference intensity due to the dominance of the fundamental frequency.

[0086] During the steady-state operation of the equipment, the weight of higher harmonics is reduced, while the weight of the fundamental frequency is increased. For example, when the equipment is operating at rated load and the current fluctuation is less than 5%, the weight of the 5th harmonic is reduced from 0.2 to 0.1, while the weight of the fundamental frequency is increased from 0.6 to 0.7. This adjustment reflects the dominant role of the fundamental frequency component in electromagnetic interference during long-term operation, and avoids the excessive amplification of small fluctuations in higher harmonics.

[0087] In some embodiments, after extracting the fundamental component and its higher harmonic components of the digital signal using the Fourier transform algorithm, and calculating the energy values ​​of the fundamental component and each higher harmonic component, the method further includes:

[0088] The energy ratio of the higher harmonic components to the fundamental component is calculated to obtain the energy proportion of the higher harmonic components.

[0089] Determine whether the energy percentage exceeds a preset energy threshold;

[0090] If the energy percentage exceeds the preset energy threshold, it is determined that there is electromagnetic interference in the power harness.

[0091] In some specific embodiments, the energy proportion of higher harmonics is calculated. For example, if the energy value of the 5th higher harmonic component is 150J and the energy value of the fundamental component is 200J, then the energy proportion of the higher harmonic components R5 = 75%.

[0092] If the proportion of any higher harmonic energy Rn exceeds a preset threshold (e.g., R5>70% or R7>60%), the system determines that there is electromagnetic interference in the power wiring harness. For example, during the start-up phase of a variable frequency motor, if the proportion of 5th harmonic energy is detected to be 75%, an early warning is triggered and the current scenario is recorded.

[0093] S104: Determine whether the electromagnetic interference intensity reaches a predetermined threshold;

[0094] The preset thresholds can be dynamically adjusted according to actual needs. For example, in the scenario of starting a variable frequency motor, the system defaults to raising the 5th and 7th harmonic thresholds to 80% and 70% respectively to accommodate the significant increase in transient high-order harmonics; during steady-state operation, they are restored to 70% and 60%.

[0095] In some scenarios, a predetermined threshold of 50μT can be set, and the frequency range threshold is 50Hz-1MHz.

[0096] S105: If the electromagnetic interference intensity reaches a predetermined threshold, it is determined that the power harness has electromagnetic interference.

[0097] Analysis of the recorded data revealed that the electromagnetic interference was significant during equipment startup, potentially affecting the normal operation of surrounding equipment. Based on this data, the wiring scheme can be adjusted by increasing the distance between the power harness and other sensitive equipment, and implementing shielding measures to effectively reduce electromagnetic interference.

[0098] In some specific embodiments, a single device uses twenty to thirty motors. The frequent start-stop cycles of large motors, especially variable frequency motors and multiple motors, along with electromagnetic changes in the electric drive unit due to load variations, cause significant interference to the power grid and power lines. Medium and high power frequency converters generate substantial high-order harmonic interference during startup, particularly the 5th and 7th harmonic components, which can reach over 70% of the 50Hz fundamental frequency. This can have a significant impact on the power grid, and in severe cases, affect the normal operation of other equipment within the same grid. When this impact exceeds the power supply safety threshold of other equipment, standardized grounding measures must be implemented, filters and reactors added, and, if necessary, a separate isolation transformer added for signal isolation. Simultaneously, the carrier frequency should be reduced to decrease interference.

[0099] Furthermore, the high-frequency components present on the transmission line can severely affect small analog signals and high-frequency communication signals transmitted within and near the network through radiation and conduction modes. In severe cases, this can cause system data distortion and communication signal failure. When this impact is detected to exceed the data distortion threshold, it is necessary to add a signal isolation module, separate and rewire the cables, especially ensuring proper grounding of signal ground and power ground, and, if necessary, increase the shielding specifications of some critical cables.

[0100] This embodiment, by real-time acquisition of electromagnetic signals from the power harness, can quickly detect abnormal states of the power harness and issue timely alarms, preventing equipment downtime or damage due to power harness failure. By setting predetermined thresholds, the electromagnetic interference intensity of the power harness to external signals can be accurately assessed, providing a basis for the electromagnetic compatibility design of the equipment. Simultaneously, by recording the electromagnetic interference state under specific scenarios, subsequent analysis and optimization of wiring design are facilitated, improving the operational stability of the equipment in complex electromagnetic environments. Furthermore, the method of this embodiment is applicable to power harness monitoring in various industrial and electronic devices, possessing broad applicability and promotional value.

[0101] Please see Figure 2 This embodiment provides an electromagnetic interference detection device 200 for power wiring harnesses, comprising:

[0102] Acquisition unit 201 is used to acquire electromagnetic signals of power harness in real time;

[0103] Preprocessing unit 202 is used to preprocess the electromagnetic signal to generate a digital signal;

[0104] Analysis unit 203 is used to perform interference intensity analysis on the digital signal to obtain electromagnetic interference intensity;

[0105] Judgment unit 204 is used to determine whether the electromagnetic interference intensity reaches a predetermined threshold.

[0106] The determination unit 205 is used to determine that the power harness has electromagnetic interference if the electromagnetic interference intensity reaches a predetermined threshold.

[0107] Furthermore, the analysis unit 203 includes:

[0108] The extraction subunit is used to extract the fundamental component and its higher harmonic components of the digital signal using the Fourier transform algorithm, and to calculate the energy value of the fundamental component and the energy value of each higher harmonic component.

[0109] The interference intensity calculation subunit is used to calculate the electromagnetic interference intensity based on the energy value of the fundamental component and the energy values ​​of each higher harmonic component.

[0110] Furthermore, the extraction subunit includes:

[0111] The first impedance acquisition subunit is used to acquire the equivalent impedance of the power harness;

[0112] The fundamental component extraction subunit is used to extract the fundamental component from the digital signal using a sliding window Fourier transform algorithm with a first predetermined step size, and to calculate the instantaneous voltage value of the fundamental component.

[0113] The fundamental component calculation subunit is used to calculate the energy value of the fundamental component based on the equivalent impedance, the instantaneous voltage value of the fundamental component, and a first predetermined step size, according to the following formula:

[0114]

[0115] Among them, E 基波 V represents the energy value of the fundamental component; 基波 (t) represents the instantaneous voltage value of the fundamental component; R represents the equivalent impedance; t1 and t2 represent the start and end times of the first predetermined step, respectively.

[0116] Furthermore, the extraction subunit also includes:

[0117] The second impedance acquisition subunit is used to acquire the equivalent impedance of the power harness;

[0118] The voltage value calculation subunit is used to extract higher harmonic components from the digital signal using a sliding window Fourier transform algorithm with a second predetermined step size, and to calculate the instantaneous voltage value of the higher harmonic components.

[0119] The higher harmonic component calculation subunit is used to calculate the energy value of the higher harmonic component based on the equivalent impedance, the instantaneous voltage value of the higher harmonic component, and a second predetermined step size, according to the following formula:

[0120]

[0121] Among them, E n V represents the energy value of higher harmonic components. n (t) represents the instantaneous voltage value of the higher harmonic components; R represents the equivalent impedance; t3 and t4 represent the start and end times of the second predetermined step, respectively.

[0122] Furthermore, the interference intensity calculation subunit includes:

[0123] The electromagnetic interference intensity calculation subunit is used to calculate the electromagnetic interference intensity according to the following formula:

[0124]

[0125] Among them, E EMI Indicates electromagnetic interference intensity; w0 represents fundamental frequency weight; E 基波 Indicates the energy value of the fundamental component; w n E represents the weight of the nth higher harmonic component; n This represents the energy value of the nth higher harmonic component; N represents the total number of higher harmonic components.

[0126] Furthermore, the electromagnetic interference intensity calculation subunit includes:

[0127] The equipment operation status acquisition subunit is used to acquire the equipment operation status;

[0128] Add a sub-unit to increase the weighting coefficient of higher harmonic components if the equipment is in startup or under sudden load change conditions;

[0129] The reduction sub-unit is used to reduce the weighting coefficient of higher harmonic components and increase the weighting of the fundamental frequency when the equipment is in steady-state operation.

[0130] Furthermore, the extraction subunit includes:

[0131] The ratio calculation subunit is used to calculate the ratio of the energy value of the higher harmonic component to the energy value of the fundamental component, so as to obtain the energy proportion of the higher harmonic component.

[0132] The percentage determination subunit is used to determine whether the energy percentage exceeds a preset energy threshold.

[0133] An interference determination subunit is used to determine that the power harness has electromagnetic interference if the energy percentage exceeds a preset energy threshold.

[0134] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and unit can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0135] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, can implement the methods provided in the above embodiments. The storage medium may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0136] The present invention also provides a computer device, which may include a memory and a processor. The memory stores a computer program, and when the processor calls the computer program in the memory, it can implement the methods provided in the above embodiments. Of course, the computer device may also include various network interfaces, power supplies, and other components.

[0137] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

[0138] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusivity.

[0139] The term "comprises" implies 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 a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for detecting electromagnetic interference in a power wiring harness, characterized in that, include: Real-time acquisition of electromagnetic signals from power wiring harnesses; The electromagnetic signal is preprocessed to generate a digital signal; The electromagnetic interference intensity is obtained by performing interference intensity analysis on the digital signal. Determine whether the electromagnetic interference intensity reaches a predetermined threshold; If the electromagnetic interference intensity reaches a predetermined threshold, it is determined that the power harness has electromagnetic interference. The interference intensity analysis of the digital signal to obtain the electromagnetic interference intensity includes: The fundamental component and its higher harmonic components of the digital signal are extracted using the Fourier transform algorithm, and the energy values ​​of the fundamental component and each higher harmonic component are calculated. The electromagnetic interference intensity is calculated based on the energy values ​​of the fundamental component and each higher harmonic component. The energy values ​​of the fundamental component were calculated as follows: Obtain the equivalent impedance of the power harness; The fundamental component is extracted from the digital signal using a sliding window Fourier transform algorithm with a first predetermined step size, and the instantaneous voltage value of the fundamental component is calculated. The energy value of the fundamental component is calculated based on the equivalent impedance, the instantaneous voltage value of the fundamental component, and the first predetermined step size, according to the following formula: ； Among them, E 基波 This represents the energy value of the fundamental component; The instantaneous voltage value of the fundamental component is represented by t1; R represents the equivalent impedance; t1 and t2 represent the start and end times of the first predetermined step, respectively. The energy values ​​of higher harmonic components were calculated as follows: Obtain the equivalent impedance of the power harness; The sliding window Fourier transform algorithm is used to extract higher harmonic components from the digital signal with a second predetermined step size, and the instantaneous voltage value of the higher harmonic components is calculated. The energy value of the higher harmonic components is calculated based on the equivalent impedance, the instantaneous voltage value of the higher harmonic components, and the second predetermined step size, according to the following formula: ； Among them, E n This represents the energy value of higher harmonic components; The instantaneous voltage value of the higher harmonic components is represented by t3; R represents the equivalent impedance; t3 and t4 represent the start and end times of the second predetermined step, respectively. The calculation of electromagnetic interference intensity based on the energy values ​​of the fundamental component and each higher harmonic component includes: Calculate the electromagnetic interference intensity using the following formula: ； wherein E EMI represents the electromagnetic interference strength; w0represents the fundamental weight; E 基波 represents the energy value of the fundamental component; w n represents the weight of the nth higher harmonic component; E n represents the energy value of the nth higher harmonic component; N represents the total number of higher harmonic components; After calculating the electromagnetic interference intensity using the following formula, it includes: Obtain the operating status of the device; If the equipment is in a startup or load change condition, increase the weighting coefficient of the higher harmonic components; If the equipment is in steady-state operation, reduce the weighting coefficient of higher harmonic components and increase the weighting of the fundamental frequency.

2. The electromagnetic interference detection method for power wiring harnesses according to claim 1, characterized in that, The process of extracting the fundamental component and its higher harmonic components of the digital signal using the Fourier transform algorithm, and calculating the energy values ​​of the fundamental component and each higher harmonic component, further includes: The energy ratio of the higher harmonic components to the fundamental component is calculated to obtain the energy proportion of the higher harmonic components. Determine whether the energy percentage exceeds a preset energy threshold; If the energy percentage exceeds a preset energy threshold, it is determined that the power harness is subject to electromagnetic interference.

3. An electromagnetic interference detection device for power wiring harnesses, characterized in that, include: The acquisition unit is used to acquire electromagnetic signals of the power harness in real time. The preprocessing unit is used to preprocess the electromagnetic signal to generate a digital signal; The analysis unit is used to perform interference intensity analysis on the digital signal to obtain the electromagnetic interference intensity; The judgment unit is used to determine whether the electromagnetic interference intensity reaches a predetermined threshold. The determination unit is used to determine that the power harness has electromagnetic interference if the electromagnetic interference intensity reaches a predetermined threshold. The analysis unit includes: The extraction subunit is used to extract the fundamental component and its higher harmonic components of the digital signal using the Fourier transform algorithm, and to calculate the energy value of the fundamental component and the energy value of each higher harmonic component. The interference intensity calculation subunit is used to calculate the electromagnetic interference intensity based on the energy value of the fundamental component and the energy values ​​of each higher harmonic component. The extraction subunit includes: The first impedance acquisition subunit is used to acquire the equivalent impedance of the power harness; The fundamental component extraction subunit is used to extract the fundamental component from the digital signal using a sliding window Fourier transform algorithm with a first predetermined step size, and to calculate the instantaneous voltage value of the fundamental component. The fundamental component calculation subunit is used to calculate the energy value of the fundamental component based on the equivalent impedance, the instantaneous voltage value of the fundamental component, and a first predetermined step size, according to the following formula: ； Among them, E 基波 This represents the energy value of the fundamental component; The instantaneous voltage value of the fundamental component is represented by t1; R represents the equivalent impedance; t1 and t2 represent the start and end times of the first predetermined step, respectively. The extraction subunit further includes: The second impedance acquisition subunit is used to acquire the equivalent impedance of the power harness; The voltage value calculation subunit is used to extract higher harmonic components from the digital signal using a sliding window Fourier transform algorithm with a second predetermined step size, and to calculate the instantaneous voltage value of the higher harmonic components. The higher harmonic component calculation subunit is used to calculate the energy value of the higher harmonic component based on the equivalent impedance, the instantaneous voltage value of the higher harmonic component, and a second predetermined step size, according to the following formula: ； Among them, E n This represents the energy value of higher harmonic components; The instantaneous voltage value of the higher harmonic components is represented by t3; R represents the equivalent impedance; t3 and t4 represent the start and end times of the second predetermined step, respectively. The interference intensity calculation subunit includes: The electromagnetic interference intensity calculation subunit is used to calculate the electromagnetic interference intensity according to the following formula: ； Among them, E EMI Indicates electromagnetic interference intensity; w0 represents fundamental frequency weight; E 基波 Indicates the energy value of the fundamental component; w n E represents the weight of the nth higher harmonic component; n This represents the energy value of the nth higher harmonic component; N represents the total number of higher harmonic components. The electromagnetic interference intensity calculation subunit includes: The equipment operation status acquisition subunit is used to acquire the equipment operation status; Add a sub-unit to increase the weighting coefficient of higher harmonic components if the equipment is in startup or under sudden load change conditions; The reduction sub-unit is used to reduce the weighting coefficient of higher harmonic components and increase the weighting of the fundamental frequency when the equipment is in steady-state operation.

4. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the electromagnetic interference detection method for power harness as described in any one of claims 1 to 2.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform the electromagnetic interference detection method for a power harness as described in any one of claims 1 to 2.

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