Three-phase power supply tail end protection method and system based on hydrogen-harmonic linkage

Abstract

The invention provides a three-phase power supply tail end protection method and system based on hydrogen-harmonic linkage, and relates to the technical field of power system safety protection, and the method comprises the steps: synchronously collecting the concentration of hydrogen released by cable insulation, cable temperature and harmonic current data; performing digital filtering and feature extraction on the collected data to obtain a hydrogen concentration mean value, a temperature rise peak value and a harmonic average current; calculating a dynamic risk index through a multi-parameter fusion risk model; triggering and executing a corresponding grading protection response according to the dynamic risk index; and the change conditions of the hydrogen concentration, the cable temperature and the harmonic current after the graded protection response is executed are monitored in real time, and a subsequent protection strategy is dynamically adjusted. According to the invention, through hydrogen-harmonic wave-temperature multi-parameter fusion sensing and frequency spectrum division cooperative treatment, on the premise of no power failure, accurate advanced early warning of cable insulation early degradation and efficient suppression of harmonic wave pollution are realized, and the problems of early warning lag, low treatment efficiency and measure separation can be solved.

Description

Technical Field

[0001] This invention relates to the field of power system safety protection technology, specifically to a three-phase power supply end protection method and system based on hydrogen-harmonic linkage. Background Technology

[0002] In the field of power system safety protection, especially in the end-point distribution systems of high harmonic pollution scenarios such as data centers, industrial plants, and hydrogen energy facilities, monitoring and early warning of early cable insulation degradation are crucial for preventing electrical fires. Existing technologies typically employ temperature threshold-based monitoring schemes (e.g., triggering an early warning when the cable temperature rise ΔT exceeds 50K) combined with active filtering devices using a fixed carrier frequency for harmonic mitigation. These schemes can, to some extent, alarm for obvious overheating faults and suppress harmonics.

[0003] However, the aforementioned existing technologies have inherent flaws: First, monitoring technologies based on a single temperature parameter have significant time lag. Due to the physical delay of heat conduction, by the time a significant temperature rise is detected, the molecular chains of the cable insulation material may have already irreversibly broken down, releasing a large amount of hydrogen gas, thus missing the optimal early warning window. Second, harmonic mitigation devices using fixed carrier frequencies are inefficient under varying load conditions, with excessively high switching losses under light load conditions, resulting in unnecessary energy waste. Furthermore, traditional magnetic ring filters, due to their empirically based air gap design, are prone to magnetic saturation when faced with characteristic harmonics above the fifth order, leading to a sharp decline in filtering efficiency.

[0004] These shortcomings together prevent existing protection systems from providing accurate early warnings of early insulation degradation without power interruption, and from forming a synergistic protection loop with efficient harmonic control, making it difficult to effectively prevent the chain reaction of electrical fires. Summary of the Invention

[0005] To address the technical problems in related technologies, this invention provides a three-phase power supply end-of-line protection method and system based on hydrogen-harmonic linkage. The core technical problem this invention aims to solve is: how to overcome the limitations of traditional technologies such as "lagging monitoring, inefficient treatment, and crude protection," and, while meeting the continuous power supply requirements of important loads, achieve accurate early warning of early cable insulation degradation (hydrogen concentration 50-100ppm, temperature rise 15-20K), while simultaneously suppressing harmonic pollution—the main cause of insulation overheating—forming an integrated closed-loop protection system. This fundamentally solves the deficiency that single technical means cannot interrupt the chain reaction of electrical fires.

[0006] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0007] According to a first aspect of the present invention, a three-phase power supply end protection method based on hydrogen-harmonic linkage is provided, comprising the following steps: Step S1: synchronously collecting hydrogen concentration, cable temperature, and harmonic current data released from cable insulation; Step S2: performing digital filtering and feature extraction on the collected data to obtain the average hydrogen concentration, peak temperature rise, and average harmonic current; Step S3: calculating a dynamic risk index based on the data obtained in Step S2 using a multi-parameter fusion risk model; Step S4: triggering and executing a corresponding graded protection response according to the threshold range of the dynamic risk index, wherein the graded protection response includes early warning, harmonic mitigation, and rapid protection; Step S5: monitoring the changes in hydrogen concentration, cable temperature, and harmonic current after the graded protection response is executed in real time, and dynamically adjusting subsequent protection strategies according to the changes.

[0008] Optionally, in step S3, the formula used by the multi-parameter fusion risk model to calculate the dynamic risk index Risk is: In the formula, , and These are the weighting coefficients, C represents the average hydrogen concentration, and C is the preset concentration value. This represents the peak temperature rise. For the preset temperature value, For harmonic average current, This is the rated current of the cable.

[0009] Optionally, in step S4, the specific strategies for triggering different responses based on the dynamic risk index Risk include: when 3 < Risk ≤ 6, starting the magnetic ring filter and performing harmonic mitigation; when 6 < Risk ≤ 8, linking the active compensation module to perform harmonic mitigation; and when 8 < Risk, performing inverse time-limited interruption.

[0010] Optionally, the inverse-time breaking adopts an inverse-time model to control the breaking time t of the circuit: In the formula, The preset minimum break time, The calibration coefficient is related to the aging condition of the cable and , For the service life of the cable, The thermal time constant of the cable. For real-time monitoring of current values, This is the rated current of the cable.

[0011] Optionally, the harmonic mitigation includes passive filtering and active compensation, wherein the passive filtering specifically uses a stepped air-gap magnetic ring filter array designed for the 3rd, 5th and 7th harmonics, and the active compensation specifically uses a parallel active module based on SiC devices.

[0012] In the stepped air gap magnetic ring filter group, for specific harmonic frequencies The number of turns n of the magnetic ring is determined by the following formula: In the formula, This is a rounding function. The permeability of free space, For the primary number of turns, This is the effective value of the rated current. The frequency is the 5th harmonic and , For process coefficient and , The saturation flux density of the magnetic core and , Remanent magnetization and , This represents the effective cross-sectional area of ​​the magnetic core.

[0013] The carrier frequency of the parallel active module based on SiC devices The calculation formula is as follows: Dynamically adjusted using an adaptive algorithm. In the formula, For load rate, For temperature compensation term and , This is the SiC junction temperature. It is a harmonic complexity compensation term and , where m is the harmonic order with a total harmonic distortion rate of >5%.

[0014] According to a second aspect of the present invention, a three-phase power supply end protection system based on hydrogen-harmonic linkage is also provided, for executing the three-phase power supply end protection method based on hydrogen-harmonic linkage as described in any of the technical solutions of the first aspect of the present invention, comprising a sensing module group, a control central unit, a governance execution module, a fast protection unit, and a mechanical support platform; wherein, the sensing module group, the control central unit, the governance execution module, and the fast protection unit are integrated and installed on the mechanical support platform; the signal output terminal of the sensing module group is connected to the input terminal of the control central unit, for providing the control central unit with monitoring signals of hydrogen concentration, cable temperature, and harmonic current; the control output terminal of the control central unit is respectively connected to the control terminals of the governance execution module and the fast protection unit.

[0015] Optionally, the sensing module group includes:

[0016] The hydrogen concentration sensor cluster uses a palladium alloy thin-film hydrogen sensor cluster to collect hydrogen concentration data.

[0017] A temperature sensor array, employing a PT1000 platinum resistance sensor, is used to acquire cable temperature.

[0018] The current sensor uses a wideband Rogowski coil to collect harmonic currents.

[0019] Optionally, the control center unit includes a signal conditioning board, a core processing board, and a communication interface board that are electrically connected in sequence; wherein, the core processing board integrates an ARM processor and an FPGA; and / or, the fast protection unit includes a solid-state relay group and its driving circuit, wherein the solid-state relay group is connected in series in the main circuit, and its control terminal is connected to the control center unit through the driving circuit.

[0020] Optionally, the governance execution module includes a passive filtering component, an active compensation component, and a heat dissipation system; the passive filtering component is a stepped air-gap magnetic ring filter group, whose input end is connected to the main circuit and whose output end is connected to the load through the heat dissipation system; the active compensation component is a parallel active module based on SiC devices, whose AC side is connected to the main circuit in parallel through a contactor; wherein, the stepped air-gap magnetic ring filter group includes multiple independent magnetic ring units, each magnetic ring unit adopts a nanocrystalline magnetic core, and a stepped air gap with a width of 0.5±0.05mm is opened on the magnetic core; each magnetic ring unit is designed for the 3rd, 5th, and 7th harmonic frequencies respectively; the power device of the parallel active module based on SiC devices is a SiC MOSFET module of model CREE CAS325M12HM2.

[0021] Optionally, the mechanical support platform is a TS35 standard industrial guide rail, on which a grounding copper busbar is integrated; the sensing module group, control center unit, governance execution module and fast protection unit are all installed on the TS35 guide rail in a pluggable manner, with an overall width of no more than 200mm.

[0022] Beneficial effects:

[0023] 1. Through the above technical solution, firstly, the present invention can solve the problems of single and lagging monitoring, and realize advanced and comprehensive early warning of early insulation degradation.

[0024] Second, the method of this invention can break through the technical barriers of monitoring and control, and form an active closed-loop protection of "detection-control-protection".

[0025] Third, the method of the present invention can improve the accuracy and reliability of early warning and reduce the risk of false alarms.

[0026] Fourth, the method of the present invention can achieve refined safety protection without interrupting power supply.

[0027] 2. Other beneficial effects or advantages of the present invention will be described in detail in the specific embodiments. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] in:

[0030] Figure 1 This is a flowchart illustrating the steps of a three-phase power supply end protection method based on hydrogen-harmonic linkage provided in an exemplary embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the overall architecture of a three-phase power supply end protection system based on hydrogen-harmonic linkage provided in an exemplary embodiment of the present invention.

[0032] Figure 3 This is a flowchart of a multi-parameter fusion algorithm provided in an exemplary embodiment of the present invention;

[0033] Figure 4 This is a comparison chart of the spectrum division of labor governance effect provided by an exemplary embodiment of the present invention. In this chart, a dual Y-axis curve is used, and the test conditions are: 380V 400A, 50Hz fundamental wave.

[0034] Figure 5 This is an exemplary embodiment of the present invention, which provides a comparison and analysis chart of early warning time. In this chart, a time series curve is used, where the horizontal axis is time (h) and the vertical axis is the parameter value.

[0035] Figure 6 This is a schematic diagram of a laboratory validation platform provided in an exemplary embodiment of the present invention.

[0036] Explanation of the labels in the attached drawings:

[0037] 101-Power interface; 102-Sensing module; 103-Control center; 104-Governance module; 105-Protection unit. Detailed Implementation

[0038] To facilitate a clearer and more accurate understanding of the technical solutions of this invention by those skilled in the art, the existing related technologies and their technical problems will be described in more detail below.

[0039] In the final distribution stages of power systems, especially in high-harmonic-pollution applications such as data centers, industrial plants, commercial complexes, and the entire hydrogen energy industry chain, the widespread use of nonlinear loads (such as IT equipment, frequency converters, and electrolytic cells) has led to severe current harmonic problems. These harmonics not only degrade power quality but also cause additional heating in cables, accelerating the aging of their insulation materials (such as cross-linked polyethylene XLPE), and are one of the main causes of electrical fires. Therefore, real-time monitoring of cable insulation and effective harmonic control are crucial to ensuring power supply safety.

[0040] Currently, existing technical solutions in this field mainly revolve around the following aspects, but all of them have significant technical bottlenecks:

[0041] First, the lag in cable insulation monitoring technology.

[0042] Current mainstream insulation monitoring methods rely on temperature threshold alarms. The underlying principle involves deploying temperature sensors (such as fiber optic or infrared sensors) on the cable surface or joints. An alarm is triggered when the detected temperature rise (ΔT) exceeds a preset threshold (e.g., 50K). However, this single-temperature-parameter-based monitoring method suffers from inherent physical lag. According to Fourier's law of thermal conductivity, heat conduction within insulation materials takes time. For a standard-thickness XLPE insulation layer, the delay from an internal overheating point to a detectable surface temperature can be tens of hours. More critically, experimental data from authoritative standards such as IEEE 1584-2018 show that in the early stages of overheating (e.g., at 130°C), the molecular chains of cable insulation begin to break and release hydrogen gas. Within 48 to 72 hours, the concentration can reach an early degradation indicator level of 50-100 ppm, while the temperature rise at this point is only about 15-20K, far below the traditional alarm threshold. This means that traditional temperature-based monitoring techniques cannot capture the key signals of early insulation degradation, with an average alarm lag time exceeding 100 hours, missing the optimal intervention window.

[0043] Second, the problem of energy efficiency imbalance in harmonic mitigation devices.

[0044] To suppress harmonics, active power filters (APFs) are widely used. Existing APF devices mostly employ silicon-based (Si) insulated-gate bipolar transistors (IGBTs) as power switching devices and are typically set to operate at a fixed carrier frequency (e.g., 20kHz). This fixed-frequency design violates the loss characteristics of power devices under a wide range of load conditions. According to SiC device application guidelines, at low load rates (e.g., <30%), switching losses dominate the total losses (reaching over 42%). However, at this point, harmonic compensation requirements are often only a small fraction of the rated capacity. This "overpowered" operating mode results in extremely low energy efficiency under light load conditions, with the device's own power consumption accounting for a high percentage (up to 3.2% in traditional solutions), contradicting the industry trend of energy conservation and emission reduction.

[0045] Third, the problem of crude design of passive filter components.

[0046] Besides active compensation, inductors using magnetic rings are also a common passive method for suppressing specific harmonic orders (such as the 3rd, 5th, and 7th). However, the design of traditional magnetic rings often relies on experience, especially the setting of its key parameter—the air gap, which is usually a single width (such as 0.2mm). This empirical design does not fully consider the saturation characteristics of the magnetic core under the action of harmonic currents of different frequencies and amplitudes. Theoretical analysis based on Ohm's law of magnetic circuits and simulation verification using software such as ANSYS Maxwell show that when there are harmonics of the 5th order or higher with large amplitudes in the system, the saturation probability of the traditionally designed magnetic ring exceeds 60%. Once the magnetic core saturates, its inductance drops sharply, and the filtering efficiency will plummet from over 90% to below 65%, essentially losing its filtering function, and may even cause new safety hazards due to saturation heating.

[0047] Fourth, there is a lack of coordination and synergy among the technical solutions.

[0048] In summary, existing technologies exhibit a fragmented approach, addressing symptoms rather than the root cause. Hydrogen detection technology (while capable of early warning) lacks effective mitigation capabilities; temperature monitoring technology lags behind and cannot pinpoint early faults; harmonic mitigation devices are either inefficient or fail due to magnetic saturation at critical moments. More importantly, these technologies lack an effective linkage mechanism, failing to form a complete protective loop. Specifically, they cannot intelligently correlate and collaboratively suppress the early warning signal of "early insulation degradation" with the fundamental cause of "harmonic pollution," thus failing to fundamentally prevent the chain reaction of electrical fires: "insulation degradation → intensified overheating → eventual combustion."

[0049] Therefore, there is an urgent need in this field for an innovative solution that can provide early and accurate warnings of cable insulation without power interruption, and simultaneously and efficiently suppress harmonics, the main cause of damage, forming an integrated closed-loop protection system of "detection-location-management-protection".

[0050] In view of this, the present invention provides a novel solution: a three-phase power supply end-of-line protection method and system based on hydrogen-harmonic linkage. The technical concept of this invention lies in establishing an intelligent linkage between "hydrogen concentration," a leading early warning indicator, and "harmonic current," a major disaster-causing factor, to construct a closed-loop protection system with multi-parameter fusion sensing and spectrum-based collaborative governance. Specifically, it abandons the traditional single and lagging temperature monitoring method, instead employing simultaneous acquisition and fusion analysis of multi-dimensional data on hydrogen, temperature, and harmonics. By establishing a nonlinear multi-parameter risk model, it achieves accurate diagnosis of early cable insulation degradation and provides early warnings exceeding 52 hours. Based on this, the harmonic mitigation task is innovatively divided according to spectral characteristics and physical effects: the optimized stepped air-gap magnetic ring is used to efficiently filter out low-order harmonics (such as the 3rd, 5th, and 7th harmonics) that cause overall heating, while the carrier frequency adaptive SiC active module is used to dynamically compensate for high-order harmonics that are prone to partial discharge. Combined with the inverse time-limited fast protection algorithm, a seamless linkage of "monitoring-early warning-location-management-protection" is finally formed, thereby blocking the chain reaction of electrical fires from the source without power interruption.

[0051] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] like Figure 1 As shown, according to a first aspect of the present invention, this embodiment provides a three-phase power supply end protection method based on hydrogen-harmonic linkage, comprising the following steps:

[0053] Step S1: Synchronously collect data on hydrogen concentration released from cable insulation, cable temperature, and harmonic current.

[0054] Step S2: Perform digital filtering and feature extraction on the collected data to obtain the average hydrogen concentration, peak temperature rise, and average harmonic current;

[0055] Step S3: Based on the data obtained in step S2, calculate the dynamic risk index using a multi-parameter fusion risk model;

[0056] Step S4: Based on the threshold range of the dynamic risk index, trigger and execute the corresponding graded protection response, which includes early warning, harmonic mitigation, and rapid protection.

[0057] Step S5: Monitor the changes in hydrogen concentration, cable temperature and harmonic current after the graded protection response is executed in real time, and dynamically adjust the subsequent protection strategy according to the changes.

[0058] Through the above technical solution, firstly, this invention can solve the problems of single-source and lagging monitoring, achieving advanced and comprehensive early warning of early insulation degradation. Specifically, traditional methods rely on a single temperature threshold alarm, which, due to the physical lag of heat conduction, cannot capture early degradation signals at the initial stage of insulation molecular chain breakage (marked by hydrogen release), resulting in a severe delay in early warning. However, this invention, firstly, enables multi-source information fusion, specifically, simultaneously collecting hydrogen concentration (a direct product of chemical degradation), temperature (a manifestation of thermal effects), and harmonic current (an electrical parameter of the main inducing factor). These three parameters are perceived from three different physical dimensions: the cause of insulation degradation (harmonics), early chemical signs (hydrogen), and later thermal results (temperature rise). Secondly, it overcomes the limitation of single-source monitoring. Specifically, by fusing the above three types of parameters with different time response characteristics, the system no longer relies on the lagging temperature rise as the sole criterion. In particular, the introduction of hydrogen concentration monitoring allows for the capture of early insulation cracking signals through abnormal changes in hydrogen concentration before the temperature rise reaches the traditional alarm threshold. Finally, it can achieve early warning. Specifically, the method of this invention can fundamentally overcome the physical lag defect of traditional temperature monitoring, and can significantly advance the warning window, providing a methodological basis for the core invention objective of 52-hour early warning, without relying on any single parameter.

[0059] Secondly, the method of this invention can break down the technical barriers between monitoring and control, forming a proactive closed-loop protection system of "detection-control-protection". Specifically, in existing related technologies, hydrogen detection only has an early warning function, harmonic control only provides passive compensation, and temperature protection is delayed. These technologies are fragmented and cannot form a linkage, thus failing to break the causal chain of harmonic-induced overheating degradation. However, the method of this invention, firstly, can achieve causal correlation and proactive intervention. Specifically, the method of this invention, for the first time, performs correlation analysis and fusion decision-making on monitoring data representing results (hydrogen, temperature rise) and monitoring data representing causes (harmonics) within the same methodological framework. Secondly, it can achieve tiered linkage response. Specifically, based on the fusion assessment results (dynamic risk index), it triggers tiered responses including early warning, harmonic control, and rapid protection. This means that the method of this invention can not only issue early warnings but also simultaneously initiate targeted harmonic control measures, suppressing the main causes of insulation degradation at the source. Finally, it can also construct a protective closed loop. Specifically, the entire process of this invention (steps S1 to S5) constitutes a complete "perception-analysis-decision-execution-feedback" closed loop. After governance measures are implemented, the system will continue to monitor parameter changes and dynamically adjust the strategy accordingly, so that protection is no longer an isolated alarm or fixed governance, but an adaptive and continuously optimized proactive security process.

[0060] Third, the method of this invention can improve the accuracy and reliability of early warning and reduce the risk of false alarms. Specifically, in the prior art, a single parameter (such as temperature) is easily affected by environmental factors and load fluctuations, which can easily lead to false alarms or missed alarms. However, this invention can not only achieve multi-dimensional cross-validation (by calculating through a multi-parameter fusion risk model, which essentially utilizes the physical correlation between hydrogen, temperature, and harmonics for cross-validation. For example, a simple instantaneous increase in temperature without accompanying abnormal hydrogen concentration and increased harmonics may be caused by environmental factors, and the risk level may not be high), but also reduce malfunctions (the decision-making mechanism of this invention based on multi-dimensional information fusion is more fault-tolerant and more accurate than the traditional method that relies on a single threshold, which can significantly reduce false alarms or unnecessary protection actions caused by interference and improve the reliability of system operation).

[0061] Fourth, the method of this invention enables refined safety protection without interrupting power supply. Specifically, traditional over-temperature protection often trips directly, affecting the continuous power supply to critical loads; while simple early warning lacks immediate intervention. However, the method of this invention, firstly, enables tiered response to ensure continuous operation. Specifically, the method adopts different levels of response based on the risk level. For low risk, only an early warning is issued; for medium risk, mitigation measures are initiated; and only for extremely high risk (e.g., Risk>8 in the following text), rapid protection (disconnection) is executed. This gradient response strategy ensures that in most early and mid-stages of risk, the system can eliminate or control risks through proactive mitigation without power interruption, fully complying with the requirements of GB 50054-2011 for "continuous power supply to critical loads." Secondly, the method of this invention makes preventative maintenance possible. Specifically, the method transforms post-event remediation (fire tripping) into in-event intervention (harmonic mitigation) and pre-event early warning, providing a feasible technical path for predictive maintenance.

[0062] In summary, the method of this invention creatively integrates and intelligently collects hydrogen monitoring, temperature monitoring, and harmonic monitoring, and based on this, drives a hierarchical linkage response mechanism to construct a proactive, advanced, and adaptive closed-loop protection system. This system, for the first time at the methodological level, achieves multi-dimensional advanced early warning of early cable insulation degradation and real-time linkage with the harmonic causes leading to this degradation, thus fundamentally overcoming the limitations of traditional technologies such as lagging monitoring, passive governance, and fragmented measures. It provides a completely new solution for electrical fire protection in high-harmonic pollution scenarios.

[0063] In one embodiment of the present invention, in step S3, the formula for calculating the dynamic risk index Risk using the multi-parameter fusion risk model can be specifically as follows: In the formula, , and These are the weighting coefficients, C represents the average hydrogen concentration, and C is the preset concentration value. This represents the peak temperature rise. For the preset temperature value, For harmonic average current, This is the rated current of the cable.

[0064] In this implementation, this calculation formula can integrate three different physical quantities reflecting chemical degradation (hydrogen), thermal effects (temperature rise), and electrical stress causes (harmonics) in a mathematical form that best fits their respective physical laws. This fundamentally overcomes the mechanical defects of traditional empirical formulas or simple linear models, enabling the calculated Risk value to more realistically and scientifically depict the actual health status and risk level of cable insulation, providing a highly reliable data foundation for subsequent decision-making.

[0065] For the hydrogen concentration term, an exponential model is used to accommodate the nonlinear acceleration characteristics of the chemical degradation process—the breakage of molecular chains in the insulating material (releasing hydrogen)—where the average hydrogen concentration is... When the concentration approaches or exceeds the preset concentration value C (critical value), the exponential function value increases sharply to accurately simulate the critical effect of insulation degradation from quantitative to qualitative change, making the model extremely sensitive to early, trace amounts of hydrogen release.

[0066] For the temperature rise term, a quadratic model is used to adapt to the simplified expression of Joule's law of heating (heat generation is proportional to the square of the current) and Arrhenius's law, which states that the thermal aging rate of insulation materials is exponentially related to temperature. The quadratic term amplifies the significant contribution of temperature rise to risk, making the model's response to overheating conditions more consistent with thermodynamic laws. For the harmonic term, a linear proportional model is used to reflect the direct driving effect of harmonic current as the main cause of insulation overheating in a linear manner. The larger the proportion of harmonic current relative to the cable's rated capacity, the more significant the additional losses and thermal stress it causes.

[0067] In one embodiment of the present invention, please refer to Figure 5 In step S4 of the present invention, the specific strategies for triggering different responses based on the dynamic risk index Risk may include: when 3 < Risk ≤ 6, starting the magnetic ring filter and performing harmonic mitigation; when 6 < Risk ≤ 8, linking the active compensation module to perform harmonic mitigation; and when 8 < Risk, performing inverse time-limited interruption.

[0068] This technical solution allows for several key advantages. First, it enables the construction of an automated decision-making rule. Once the Risk value is calculated, the system automatically triggers pre-defined, optimal mitigation or protection actions based on the corresponding harmonic range, without manual intervention. Second, regarding specific strategies, when the risk initially manifests (3 < Risk ≤ 6), the magnetic ring filter is prioritized for harmonic mitigation. As a passive device, the magnetic ring offers advantages such as simple structure, low cost, high reliability, and extremely low power consumption. Using the magnetic ring at this stage effectively suppresses the most prevalent harmonics (e.g., 3rd, 5th, and 7th orders) with minimal economic and energy costs, attempting to mitigate the risk in its early stages with high efficiency and energy savings. When the risk escalates (6 < Risk ≤ 8), indicating that the initial mitigation may be insufficient or the harmonic composition is more complex, the system activates the active compensation module. The active module offers fast dynamic response, high compensation accuracy, and the ability to handle harmonics across a wider spectrum. Activating active compensation at this stage strongly complements and upgrades the passive mitigation approach, aiming to curb further risk deterioration with more powerful technical means. When the risk index exceeds the highest threshold (8 < Risk), it means that insulation degradation may have entered an emergency state, potentially triggering an accident at any time. At this point, the system decisively executes a rapid disconnection. This establishes an insurmountable safety baseline, ensuring that personal and equipment safety becomes the absolute priority when the system faces the risk of collapse.

[0069] In one embodiment of the present invention, the inverse-time limiting segmentation of the present invention uses an inverse-time limiting model to control the segmentation time t of the circuit, and its calculation formula can be: In the formula, The preset minimum break time, The calibration coefficient is related to the aging condition of the cable and , For the service life of the cable, The thermal time constant of the cable. For real-time monitoring of current values, This is the rated current of the cable.

[0070] This implementation effectively addresses the fundamental flaw of traditional inverse-time protection models, which are disconnected from the actual aging state of cables, achieving accurate and up-to-date protection characteristics. Specifically, traditional inverse-time protection (e.g., thermal overload protection based on the IEC 60287 standard) uses a fixed time-current characteristic curve. This curve is designed based on the insulation material and thermal parameters of new cables. However, after long-term operation, the insulation material (e.g., XLPE) of the cable undergoes thermal and electrical aging, leading to a decrease in its thermal tolerance (the equivalent value of the thermal time constant τ). Continuing to use a fixed curve for new cables will result in protection actions that are too early (false activation) or too late (failure to activate), failing to accurately match the cable's current actual safety boundaries. This invention introduces dynamic calibration of cable aging (calibration coefficient K), meaning that the inverse-time model of this invention is no longer static but an adaptive model that dynamically evolves with the cable's service life.

[0071] In other words, this invention introduces a calibration coefficient K that is linearly related to the cable's service life, creating an intelligent protection method to break through the static and rigid limitations of traditional inverse-time protection models. This allows the protection action time to dynamically track and accurately match the cable's insulation withstand capability, which changes continuously with the cable's service life. This not only significantly improves the accuracy and safety of emergency disconnection protection and effectively prevents insufficient protection for aging cables, but also provides an innovative technical approach to optimizing system-level protection coordination and reducing maloperation through its state-adaptive characteristics, achieving a leap from fixed protection to customized, adaptive protection.

[0072] In this embodiment, it should be noted that the calibration coefficient K in the calculation formula for the breaking time t of the inverse time-delay model control circuit can achieve precise matching. Specifically, as the cable's service life increases... As the current increases, the value of K increases linearly. Substituting this into the inverse time formula, at the same overcurrent factor ( Under these conditions, the calculated breaking time t will become longer. This intuitively reflects engineering reality: aging cable insulation is more fragile, and its ability to withstand short-term overcurrent thermal shock decreases, thus requiring more rapid protective actions to prevent thermal breakdown. This model uses mathematical methods to make the protection characteristic curve shift to the right or become steeper in sync with cable aging, thereby always accurately aligning with the cable's current true thermal safety limit.

[0073] In one embodiment of the present invention, the harmonic mitigation of the present invention includes passive filtering and active compensation, wherein the passive filtering specifically uses a stepped air gap magnetic ring filter group designed for the 3rd, 5th and 7th harmonics, and the active compensation specifically uses a parallel active module based on SiC devices.

[0074] Among them, in the stepped air gap magnetic ring filter group, for specific harmonic frequencies The number of turns n of the magnetic ring is determined by the following formula: In the formula, This is a rounding function. The permeability of free space, For the primary number of turns, This is the effective value of the rated current. The frequency is the 5th harmonic and , For process coefficient and , The saturation flux density of the magnetic core and , Remanent magnetization and , This represents the effective cross-sectional area of ​​the magnetic core.

[0075] Carrier frequency of parallel active modules based on SiC devices The calculation formula is as follows: Dynamically adjusted using an adaptive algorithm. In the formula, For load rate, For temperature compensation term and , This is the SiC junction temperature. It is a harmonic complexity compensation term and , where m is the harmonic order where the total harmonic distortion rate of the current is greater than 5%.

[0076] In this embodiment, firstly, the method of the present invention can provide a precise theoretical design tool for passive magnetic ring filters, fundamentally solving the problems of magnetic saturation and low efficiency caused by traditional empirical design. In existing related technologies, traditional magnetic ring design relies on experience (such as a fixed air gap of 0.2 mm), and has not established a quantitative relationship between harmonic current and the physical characteristics of the magnetic core, resulting in issues with specific harmonics (such as the 5th order, ...). Under high current, the inductance is easily saturated, and after saturation, the inductance drops sharply, and the filtering efficiency plummets from >90% to below 65%, or even fails. The method of this invention, however, uses a turns-by-turn calculation formula (…). This is the first time that the core variables of magnetic circuit design have been directly and precisely linked to the electrical parameters of the target harmonic control. Each term in the formula (vacuum permeability)... Primary number of turns N, effective current value Target harmonic frequency Magnetic core saturation flux With remanence Effective cross-sectional area All of these have clear physical meaning and measurability. Furthermore, the core purpose of this formula is to ensure that the rated harmonic current is within acceptable limits by calculating the appropriate number of turns n. and specific frequencies Under the influence of this action, the operating point of the magnetic core is far from the saturation region ( (Provides a safety margin). The stepped air-gap magnetic ring filter array designed using this model can fundamentally reduce the magnetic saturation probability from over 60% in traditional designs to an extremely low level (e.g., below 5%), thereby ensuring that it maintains high inductance and stable filtering performance (efficiency ≥ 95%) throughout the entire operating range.

[0077] Secondly, the method of this invention enables optimal energy efficiency operation of the active compensation module, completely overcoming the energy efficiency imbalance problem of fixed carrier frequency over a wide load range. Specifically, in existing related technologies, traditional active power filters (APFs) use a fixed carrier frequency (e.g., 20kHz). Under light load (η<30%), the switching loss accounts for an excessively high proportion of the total loss (up to 42%), causing an energy efficiency imbalance of "overpowered power," with light load power consumption reaching as high as 3.2%, which contradicts the energy-saving target. The method of this invention introduces a load rate adaptive dynamic frequency mechanism (…). ),in, The project established the carrier frequency. With real-time load rate The direct linear relationship between the load rate and the carrier frequency (the lower the load rate, the lower the carrier frequency) is observed. Furthermore, since the switching losses of SiC devices are approximately proportional to the carrier frequency, they automatically decrease under light load conditions. This strategy can directly and significantly reduce switching losses. Thus, it can reduce the system power consumption under light load conditions from 3.2% of the traditional solution to 0.76%, achieving a 76% reduction in light load losses. This addresses the industry pain point of excessive energy consumption by the APF under partial load operation, significantly improving the overall system energy efficiency. Furthermore, temperature compensation (… Harmonic complexity compensation term ( The introduction of [missing information] enables the algorithm of this invention to possess multi-dimensional environmental adaptability. Temperature compensation can be applied at the junction temperature. The frequency is suppressed when the frequency is increased to prevent a surge in losses and thermal runaway at high temperatures; harmonic compensation, on the other hand, increases the frequency to address complex harmonic spectra, thereby enhancing dynamic compensation capabilities. This enables the active module to maintain an optimal balance between performance and energy efficiency in varying temperature and harmonic environments.

[0078] Third, the method of this invention, through the division of spectrum between "passive targeted filtering" and "active adaptive compensation," can construct an efficient, reliable, and energy-saving collaborative governance system (see [link to invention]). Figure 4 Specifically, the magnetic ring is designed to target the 3rd, 5th, and 7th harmonics (using a formula to target them). The design utilizes the high reliability and low loss characteristics of the magnetic ring for basic filtering; the SiC active module acts as a "mobile" force, dynamically compensating for harmonics of the 11th order and above, as well as other high-frequency and varying harmonics, through adaptive algorithms. This division of labor avoids resource waste and adverse effects between devices. Simultaneously, the precise design of the magnetic ring ensures efficient and stable control of major harmonics; the adaptive operation of the active module ensures accurate and flexible response to full-spectrum, time-varying harmonics. The combination of these two approaches not only achieves a comprehensive control efficiency of up to 96.4%, but also minimizes the energy consumption of the control process itself (especially under light loads), optimizing both "control effectiveness" and "control energy efficiency" simultaneously.

[0079] The method for determining the parameters of the risk model of the present invention will be described below with reference to an exemplary embodiment.

[0080] 1. Experimental Design:

[0081] Temperature gradient: 80℃, 100℃, 130℃; Voltage stress: 1.0Un, 1.1Un, 1.15Un;

[0082] Sample: 10kV XLPE cable (240mm²), 3 pieces per group, aging time 1000-5000 hours.

[0083] 2. Data Collection:

[0084] Hydrogen concentration: Gas chromatograph (Agilent 490, accuracy 0.1ppm); Temperature: Embedded PT100 (accuracy ±0.1℃); Harmonics: Power analyzer (Yokogawa WT1800, THD accuracy 0.05%).

[0085] 3. Model Fitting:

[0086] Using the SGDRegressor from the Python sklearn library, with loss function 'huber', regularization 'l2', and α=0.01; optimal parameters: =0.65, =0.25, =0.45, validation set =0.983.

[0087] The optimization process of the magnetic ring air gap of the present invention will be described below with reference to an exemplary embodiment.

[0088] 1. Theoretical calculations:

[0089] According to the formula n=17 turns, the air gap is 0.5mm; edge effect correction: number of air gaps=15, each air gap width is 0.5mm, and the interval is 5mm.

[0090] 2. Simulation verification:

[0091] ANSYS Maxwell settings:

[0092] Physical fields: magnetic field, harmonic analysis; Material: nanocrystalline 1K107, μr= Excitation: 5th harmonic current 100A, frequency 250Hz;

[0093] Results: Maximum magnetic flux density 0.28T < 0.35T, loss density .

[0094] 3. Tolerance Analysis:

[0095] An air gap tolerance of 0.05 mm corresponds to a magnetic flux density fluctuation of ±5%, which is still <0.35 T.

[0096] With a turns tolerance of ±1, when n=16, B=0.3T, and when n=18, B=0.26T, both are safe.

[0097] The following describes the FPGA implementation of the adaptive carrier frequency of the present invention with reference to an exemplary embodiment.

[0098] 1. Algorithm Discretization:

[0099] Sampling period T = 10 ms; Difference equation:

[0100] ;

[0101] Quantization: 10-bit fixed-point, resolution 0.01kHz.

[0102] 2. Resource consumption:

[0103] FPGA (XC7K325T):

[0104] LUTs: 2456 (3%); Registers: 1872 (2%); DSP48s: 8 (1%); Maximum clock frequency: 250MHz.

[0105] 3. Real-time analysis:

[0106] Calculation period: 400ns < 10ms, meeting real-time requirements; frequency adjustment step size: 0.1kHz, maximum adjustment rate: 100kHz / s.

[0107] The following is a simulation verification of the effectiveness of the present invention.

[0108] I. Simulation Verification of Multi-Parameter Risk Model

[0109] 1. Simulation Platform

[0110] Software: Python + scikit-learn;

[0111] Dataset: Generates 1000 sets of simulation data, including:

[0112] 20-100ppm 5-50K :0-50A; Actual Risk Level: Obtained by interpolation of accelerated aging test data.

[0113] 2. Validation metrics: Mean Squared Error (MSE) = 0.015; Mean Absolute Error (MAE) = 0.2; =0.985; Early warning accuracy: 98.7% (threshold Risk=5).

[0114] 3. Comparative Experiment

[0115] Single hydrogen model: =0.85, MAE=0.5; Single temperature model: =0.72, MAE=0.8;

[0116] The model of this invention improves performance by 15%-26%.

[0117] II. Simulation of Spectrum Division Governance

[0118] 1. System parameters: Power grid: 380V / 50Hz, three-phase four-wire; Load: nonlinear load (THDi=25%); Magnetic ring: n=17, L=12mH; SiC module: switching frequency 4-25kHz.

[0119] 2. Simulation Results

[0120] Before treatment, THDi = 25% (5 times = 85A, 7 times = 63A, 11 times = 42A);

[0121] After treatment with the magnetic ring, THDi = 12% (5 times = 8A, 7 times = 7A);

[0122] THDi after SiC treatment = 2.8% (11 times = 3A);

[0123] Total loss: Fixed 20kHz = 430W, adaptive = 229W, a reduction of 47%.

[0124] III. Matlab Simulation for Protecting Inverse Time Limitation Characteristics

[0125] 1. Cable parameters: Model: YJV22-10kV-3×240; Thermal time constant τ=800s;

[0126] Aging life In the year, K = 14.5 + 0.0018 × 5 = 14.509.

[0127] 2. Simulation Working Conditions

[0128] Overload factor: =2; Traditional inverse time limit: t=14.76 / 3=4.92s;

[0129] The model of this invention: t = max(0.05, 14.509 × 800 / 3) = 3869.07 s;

[0130] Actual thermal breakdown time: 3800s, error 1.82%, while the error of the traditional model is greater than 70%.

[0131] According to a second aspect of the present invention, a three-phase power supply end protection system based on hydrogen-harmonic linkage is also provided, for implementing the three-phase power supply end protection method based on hydrogen-harmonic linkage as described in any of the technical solutions of the first aspect of the present invention, comprising a sensing module group, a control central unit, a governance execution module, a fast protection unit, and a mechanical support platform; wherein, the sensing module group, the control central unit, the governance execution module, and the fast protection unit are integrated and installed on the mechanical support platform; the signal output terminal of the sensing module group is connected to the input terminal of the control central unit, for providing the control central unit with monitoring signals of hydrogen concentration, cable temperature, and harmonic current; the control output terminal of the control central unit is respectively connected to the control terminals of the governance execution module and the fast protection unit.

[0132] The following description, in conjunction with an exemplary embodiment, illustrates the three-phase power supply end protection system based on hydrogen-harmonic linkage of the present invention.

[0133] 1. System overall architecture.

[0134] Adopting a three-tiered integrated architecture of "perception-decision-execution" (see also...) Figure 2 All modules are mounted via TS35 standard DIN rails (total width ≤ 200mm) and support hot-swappable maintenance, specifically including:

[0135] Sensing module group 102: wideband Rogowski coil (bandwidth DC-30MHz, current measurement range 0-600A, accuracy 0.2 grade), PT1000 temperature sensor array (temperature measurement range -50℃~200℃, accuracy ±0.1℃), palladium alloy thin film hydrogen sensor cluster (detection range 0-1000ppm, resolution 1ppm, response time <10s).

[0136] Control center unit 103: signal conditioning board (adjustable gain range 1-100 times), ARM Cortex-A9+FPGA (XC7K325T) core board (computation cycle < 5ms), communication interface (supports EtherCAT / Modbus-TCP / LoRa);

[0137] Governance Execution Module 104: Stepped air gap magnetic ring filter group (for 3rd / 5th / 7th harmonics), SiC active module (CREE CAS325M12HM2, 1200V / 325A), aluminum heat dissipation system (thermal resistance 0.22K / W).

[0138] Fast protection unit 105: solid-state relay group (breaking time <100ms), drive circuit (adjustable overcurrent protection threshold).

[0139] 2. Core theoretical models and algorithms.

[0140] (1) Multi-parameter fusion risk model.

[0141] Based on the fitting of a 2000-hour accelerated aging test (XLPE cable at 130℃ thermal-electrical combined stress), the dynamic risk index calculation formula is as follows: ;in, It is the concentration of hydrogen gas released from the cable insulation (unit: ppm). Critical concentration for cracking (IEEE 1797-2017 standard). It is the change in cable temperature relative to ambient temperature (unit: K). The ambient temperature reference is taken as the thermodynamic temperature corresponding to 25℃. It is the average current of the 5th / 7th / 11th harmonics (unit: A). The rated current of the cable (unit: A);

[0142] Weighting coefficients: ∈[0.6,0.7] (proportion of hydrogen contribution) ∈[0.2,0.3] (proportion of contribution to temperature rise) ∈[0.4,0.5] (harmonic contribution ratio), and Optimized using a genetic algorithm, the goodness of fit was R² = 0.983.

[0143] (2) Optimization model of air gap of magnetic ring.

[0144] Based on Ohm's law for magnetic circuits and ANSYS Maxwell simulation, the formula for calculating the number of turns of a magnetic ring is as follows:

[0145]

[0146] in, Vacuum permeability), N=1 (number of primary turns); (Rated current RMS value) The second harmonic frequency is 50Hz (fundamental wave); k = 0.75 ± 0.05 (process factor, considering winding gap / core dispersion). (saturation magnetic flux density of nanocrystalline magnetic core) remanence); Effective cross-sectional area of ​​the magnetic core (corresponding to a Φ80×50×25mm magnetic ring).

[0147] Calculation results: n=16±1, the actual use is 17 turns + 15 stepped air gaps (width 0.5±0.05mm), the magnetic saturation probability is <5% (60% in traditional design).

[0148] (3) SiC module adaptive carrier frequency algorithm.

[0149] Based on the optimization of Infineon's SiC device application guide (AN2023-02), the formula for dynamic carrier frequency adjustment is as follows: ;

[0150] in, For load rate (%, range 20%-100%), the base frequency is 4kHz (when η=30%), and the frequency increases by 3kHz for every 10% increase in load rate; It is the temperature compensation term (kHz). , The SiC junction temperature (°C) is set; compensation is activated when the temperature exceeds 60°C to prevent a surge in high-temperature losses. It is the harmonic complexity compensation term (kHz). m is the harmonic order of THDi > 5% (e.g., m = 3 for 5 / 7 / 11th harmonics, with a compensation of 1.5kHz); the frequency range is 4-25kHz (the optimal switching frequency range for SiC devices, with switching losses < 180W).

[0151] (4) Fast protection inverse time limit model.

[0152] Based on the IEC 60287 cable thermal characteristic standard, the formula for calculating the breaking time is: ;in, The inherent breaking time of the circuit breaker (as required by GB50054-2011); K is the aging calibration coefficient. , (This refers to the cable's service life, in years). Let be the cable thermal time constant (s). , (specific heat capacity of copper) conductor cross-sectional area) (specific heat capacity) Conductor-insulation thermal resistance);

[0153] Example: , In that year, The error compared to the actual measurement is <2%.

[0154] 3. Closed-loop workflow (see also) Figure 3 ).

[0155] (1) Data acquisition (T+0ms): Synchronously acquire hydrogen concentration, cable temperature and harmonic current, sampling rate 10kHz;

[0156] (2) Signal processing (T+1ms): Digital filtering (50Hz notch filter + low-pass filter), feature extraction mean peak value ;

[0157] (3) Risk calculation (T+2ms): Substitute into the multi-parameter model to calculate the Risk index (e.g., Risk=5.2 triggers Level 1 warning, Risk=7.2 triggers emergency protection).

[0158] (4) Decision execution (T+3ms):

[0159] Level 1 warning (3 < Risk ≤ 6): Enhanced monitoring (sampling rate increased to 20kHz) + activation of magnetic ring filtering;

[0160] Level 2 warning (6 < Risk ≤ 8): SiC module boost compensation (current increased by 25%, harmonic mitigation capability improved by 30%) + area ventilation;

[0161] Emergency protection (Risk > 8): Solid-state relay tripping (<100ms) + cloud alarm;

[0162] (5) Effect feedback (T+4ms): Real-time monitoring , THDi changes, and strategies are dynamically adjusted.

[0163] III. Verification of Technological Synergistic Effects (COMSOL Multiphysics Simulation, please refer to...) Figure 6 ).

[0164] 1. Precise positioning effect: The spatial overlap between the area of ​​concentrated harmonic current (such as cable joint) and the hydrogen diffusion source is up to 92%, and the defect positioning error is <1m by correlating the two.

[0165] 2. Positive feedback suppression: After harmonic mitigation (THDi reduced from 18% to 2.8%), the cable temperature rise rate decreased from 0.5K / h to 0.1K / h, and hydrogen release was reduced by 65%;

[0166] 3. Time scale matching: The hydrogen monitoring response time (<10s), harmonic mitigation response time (<5ms), and protection action time (<100ms) form a graded response to avoid false actions.

[0167] The following describes the three-phase power supply end protection system based on hydrogen-harmonic linkage of the present invention in conjunction with three exemplary embodiments.

[0168] Implementation method 1: Data center terminal power distribution protection (400A / 380V, IT load).

[0169] 1. System configuration.

[0170] Sensing module: One hydrogen sensor is installed every 5 meters of cable (installed inside the cable tray), and two PT1000 (temperature difference monitoring) sensors are deployed at the cable joints. A Rogowski coil is fitted onto the incoming cable (80mm diameter).

[0171] Magnetic ring filter: adopts, for example Figure 5 The design features n=17 turns and an air gap of 0.5mm, targeting the 3rd / 5th / 7th harmonics (the main harmonics of IT loads).

[0172] SiC module: CREE CAS325M12HM2, carrier frequency adaptive range 4-25kHz, frequency drops to 8kHz under light load (η=20%), switching loss drops from 180W to 95W;

[0173] Protection parameter: Trigger interruption when Risk > 8. Forced protection (<100ms).

[0174] 2. Verification process and results.

[0175] Initial state (0h): , T=32℃, THDi=18%, Risk=2.1;

[0176] Risk evolution (4h): Simulated cable insulation micro-cracks (thermal aging 130℃ pretreatment). , THDi=22%, Risk=5.2 (Triggered Level 1 Warning);

[0177] Automatic response: The magnetic ring filter starts (3rd / 5th / 7th harmonic suppression), and the SiC module switches to boost mode (current increases by 25%, harmonic suppression capability is improved by 30%).

[0178] Effect confirmed (6h): Stabilized at 55 ppm (without further increase), THDi decreased to 3.2%. Stable at 14K, Risk=5.3 (alert lifted).

[0179] Implementation Method 2: Power Distribution Protection for Hydrogen Electrolyzer (630A / 10kV, 6-Pulse Rectification).

[0180] 1. Special configuration.

[0181] Harmonic characteristics: Electrolytic cell with 6-pulse rectification, characteristic harmonics of the 5th / 7th / 11th / 13th orders, THDi=25%;

[0182] Protection strategy: The magnetic ring focuses on suppressing the 5th / 7th harmonics (95% efficiency), and the SiC module targets the 11th / 13th harmonics (99% efficiency) to avoid harmonics causing overheating of the electrolytic cell electrodes;

[0183] Safety linkage: When Risk > 7, only the faulty branch is cut off (without affecting other electrolyzers) to ensure continuous hydrogen production (a key requirement for hydrogen energy facilities).

[0184] 2. Verification results.

[0185] After harmonic mitigation, THDi = 2.5% (compliant with IEC 61000-3-6 medium voltage standard); cable temperature rise decreased from 45K to 18K, hydrogen release was reduced by 70%; protection action time was 85ms (less than the 200ms emergency shutdown response time of the electrolytic cell).

[0186] Implementation Method 3: Parameter Calibration Experiment (Arrhenius Accelerated Aging).

[0187] Based on formula Calibrate the K value in the Risk model:

[0188] parameter: , (Activation energy for molecular chain breakage) , , , (overvoltage);

[0189] Experiment: 2000 hours of accelerated aging, recording different... The K value under the given condition is fitted to obtain ;

[0190] Application: After 5 years of cable operation, the K value increased from 14.5 to 14.509, and the inverse time protection time was adjusted from 3867s to 3869.07s to match the insulation withstand capability after aging.

[0191] In one embodiment of the present invention, the sensing module group of the present invention may include:

[0192] The hydrogen concentration sensor cluster uses a palladium alloy thin-film hydrogen sensor cluster to collect hydrogen concentration data.

[0193] A temperature sensor array, employing a PT1000 platinum resistance sensor, is used to acquire cable temperature.

[0194] The current sensor uses a wideband Rogowski coil to collect harmonic currents.

[0195] In one embodiment of the present invention, the control center unit includes a signal conditioning board, a core processing board, and a communication interface board that are electrically connected in sequence; wherein, the core processing board integrates an ARM processor and an FPGA; and / or,

[0196] The fast protection unit includes a solid-state relay group and its driving circuit. The solid-state relay group is connected in series in the main circuit, and its control terminal is connected to the control center unit through the driving circuit.

[0197] In one embodiment of the present invention, the governance execution module of the present invention includes a passive filtering component, an active compensation component, and a heat dissipation system;

[0198] The passive filter component is a stepped air gap magnetic ring filter group, whose input end is connected to the main circuit and whose output end is connected to the load through a heat dissipation system.

[0199] The active compensation component is a parallel active module based on SiC devices, and its AC side is connected to the main circuit in parallel via a contactor.

[0200] The stepped air gap magnetic ring filter group includes multiple independent magnetic ring units. Each magnetic ring unit adopts a nanocrystalline magnetic core, and a stepped air gap with a width of 0.5±0.05mm is opened on the magnetic core. Each magnetic ring unit is designed for the 3rd, 5th and 7th harmonic frequencies respectively.

[0201] The parallel active module based on SiC devices uses SiC MOSFET modules of model CREE CAS325M12HM2 as its power devices.

[0202] In one embodiment of the present invention, the mechanical support platform of the present invention is a TS35 standard industrial guide rail, on which a grounding copper busbar is integrated; the sensing module group, the control center unit, the governance execution module and the fast protection unit are all installed on the TS35 guide rail in a pluggable manner, and the overall width is no more than 200mm.

[0203] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A three-phase power supply end protection method based on hydrogen-harmonic linkage, characterized in that, Includes the following steps: Step S1: Synchronously collect data on hydrogen concentration released from cable insulation, cable temperature, and harmonic current. Step S2: Perform digital filtering and feature extraction on the collected data to obtain the average hydrogen concentration, peak temperature rise, and average harmonic current; Step S3: Based on the data obtained in step S2, calculate the dynamic risk index using a multi-parameter fusion risk model; Step S4: Based on the threshold range of the dynamic risk index, trigger and execute the corresponding graded protection response, which includes early warning, harmonic mitigation, and rapid protection; Step S5: Monitor the changes in hydrogen concentration, cable temperature and harmonic current after the graded protection response is executed in real time, and dynamically adjust the subsequent protection strategy according to the changes.

2. The three-phase power supply end protection method based on hydrogen-harmonic linkage according to claim 1, characterized in that, In step S3, the formula used by the multi-parameter fusion risk model to calculate the dynamic risk index Risk is: In the formula, , and These are the weighting coefficients, C represents the average hydrogen concentration, and C is the preset concentration value. This represents the peak temperature rise. For the preset temperature value, For harmonic average current, This is the rated current of the cable.

3. The three-phase power supply end protection method based on hydrogen-harmonic linkage according to claim 1, characterized in that, In step S4, the specific strategies for triggering different responses based on the dynamic risk index Risk include: When 3 < Risk ≤ 6, activate the magnetic ring filter and perform harmonic mitigation; When 6 < Risk ≤ 8, the active compensation module is activated to mitigate harmonics. When 8 < Risk, perform inverse time limit break.

4. The three-phase power supply end protection method based on hydrogen-harmonic linkage according to claim 3, characterized in that, The inverse time-limited segmentation uses an inverse time-limited model to control the segmentation time t of the circuit: In the formula, The preset minimum break time, The calibration coefficient is related to the aging condition of the cable and , For the service life of the cable, The thermal time constant of the cable. For real-time monitoring of current values, This is the rated current of the cable.

5. The three-phase power supply end protection method based on hydrogen-harmonic linkage according to claim 1, characterized in that, The harmonic mitigation includes passive filtering and active compensation. Specifically, the passive filtering uses a stepped air-gap magnetic ring filter array designed for the 3rd, 5th, and 7th harmonics, and the active compensation uses a parallel active module based on SiC devices. In the stepped air gap magnetic ring filter group, for specific harmonic frequencies The number of turns n of the magnetic ring is determined by the following formula: In the formula, This is a rounding function. The permeability of free space, For the primary number of turns, This is the effective value of the rated current. The frequency is the 5th harmonic and , For process coefficient and , The saturation flux density of the magnetic core and , Remanent magnetization and , This represents the effective cross-sectional area of ​​the magnetic core. The carrier frequency of the parallel active module based on SiC devices The calculation formula is as follows: Dynamically adjusted using an adaptive algorithm. In the formula, For load rate, For temperature compensation term and , This is the SiC junction temperature. It is a harmonic complexity compensation term and , where m is the harmonic order where the total harmonic distortion rate of the current is greater than 5%.

6. A three-phase power supply end protection system based on hydrogen-harmonic linkage, characterized in that, The method for implementing the three-phase power supply end protection method based on hydrogen-harmonic linkage as described in any one of claims 1 to 5 includes a sensing module group, a control central unit, a governance execution module, a fast protection unit, and a mechanical support platform; The sensing module group, the control center unit, the governance execution module, and the rapid protection unit are integrated and installed on the mechanical support platform. The signal output terminal of the sensing module group is connected to the input terminal of the control center unit, and is used to provide the control center unit with monitoring signals of hydrogen concentration, cable temperature and harmonic current. The control output terminal of the control center unit is connected to the control terminals of the governance execution module and the fast protection unit, respectively.

7. The three-phase power supply end protection system based on hydrogen-harmonic linkage according to claim 6, characterized in that, The sensing module group includes: The hydrogen concentration sensor cluster uses a palladium alloy thin-film hydrogen sensor cluster to collect hydrogen concentration data. A temperature sensor array, employing a PT1000 platinum resistance sensor, is used to acquire cable temperature. The current sensor uses a wideband Rogowski coil to collect harmonic currents.

8. The three-phase power supply end protection system based on hydrogen-harmonic linkage according to claim 6, characterized in that, The control center unit includes a signal conditioning board, a core processing board, and a communication interface board that are electrically connected in sequence; wherein, the core processing board integrates an ARM processor and an FPGA; and / or, The fast protection unit includes a solid-state relay group and its driving circuit. The solid-state relay group is connected in series in the main circuit, and its control terminal is connected to the control center unit through the driving circuit.

9. The three-phase power supply end protection system based on hydrogen-harmonic linkage according to claim 6, characterized in that, The governance execution module includes a passive filtering component, an active compensation component, and a heat dissipation system; The passive filter component is a stepped air gap magnetic ring filter group, whose input end is connected to the main circuit and whose output end is connected to the load through the heat dissipation system. The active compensation component is a parallel active module based on SiC devices, and its AC side is connected to the main circuit in parallel via a contactor. The stepped air gap magnetic ring filter assembly includes multiple independent magnetic ring units. Each magnetic ring unit uses a nanocrystalline magnetic core, and a stepped air gap with a width of 0.5±0.05mm is opened on the magnetic core. Each magnetic ring unit is designed for the 3rd, 5th and 7th harmonic frequencies, respectively. The parallel active module based on SiC devices uses a SiC MOSFET module with model number CREE CAS325M12HM2 as its power device.

10. The three-phase power supply end protection system based on hydrogen-harmonic linkage according to claim 6, characterized in that, The mechanical support platform is a TS35 standard industrial guide rail, on which a grounding copper busbar is integrated; the sensing module group, control center unit, governance execution module and fast protection unit are all installed on the TS35 guide rail in a pluggable manner, with an overall width of no more than 200mm.

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