A low-loss start-up surge suppression method

Abstract

This invention relates to the field of startup surge suppression technology. Specifically, it relates to a low-loss startup surge suppression method. The method includes the following steps: S1, collecting the equipment load status and current-limiting device temperature before startup, and simultaneously acquiring historical startup data of the electrical equipment. Based on the equipment load status and the current-limiting device temperature, the historical startup data is classified into different status types. This invention uses a dual-loop architecture of current-limiting circuit and bypass circuit. Immediately after startup, the main circuit is switched to the pure copper bypass circuit, and the current-limiting circuit completely exits operation. There is no additional power loss caused by any series impedance, completely solving the problem of continuous heating and low energy efficiency caused by long-term series connection of traditional current-limiting components. Simultaneously, a standard startup current curve is generated based on historical successful startup data to accurately locate the optimal switching time and minimize the operating time of the current-limiting circuit.

Description

Technical Field

[0001] This invention relates to the field of startup surge suppression technology, and more specifically, to a low-loss startup surge suppression method. Background Technology

[0002] Surge suppression technology is one of the core technologies to ensure the safe and reliable operation of electrical equipment. Its core function is to suppress the peak surge current generated by the rapid charging of the downstream bus capacitor when the electrical equipment is powered on, so as to avoid the surge current causing instantaneous breakdown or thermal damage to core components such as power switches, rectifier bridges, and fuses in the circuit. At the same time, it prevents the surge impact from causing the grid voltage drop and affecting the normal operation of other equipment in the same power supply network.

[0003] Existing surge suppression technology is mainly applied to electrical equipment scenarios with large capacitive loads, including industrial switching power supplies, energy storage converters, frequency converters, new energy vehicle on-board chargers, data center uninterruptible power supplies, and various power equipment in industrial automated production lines. With the rapid development of power electronics technology, electrical equipment in the above fields is developing towards high power, high density, and high integration. The bus capacitor capacity of the equipment is constantly increasing, and the peak value of the surge current is also significantly increased. Currently, mainstream surge suppression solutions mainly include fixed current-limiting resistor series solutions, NTC thermistor current-limiting solutions, and relay bypass current-limiting solutions. Fixed current-limiting resistor solutions are simple in structure, but the current-limiting resistor is connected in series in the main circuit for a long time, resulting in continuous power loss and heat generation, significantly reducing the operating efficiency of the equipment. Furthermore, in high-power scenarios, a large heat dissipation device is required, increasing the equipment size and cost. NTC thermistor solutions utilize the characteristic that resistance decreases with increasing temperature to achieve current limiting. While this reduces steady-state losses, frequent start-stop cycles can lead to a significant decrease in current-limiting capability due to residual heat from the thermistor, posing a risk of surge suppression failure. Additionally, excessively high initial resistance at low temperatures can prolong equipment startup time. Relay bypass solutions achieve low-loss operation by closing the relay after startup to short-circuit the current-limiting element. However, mechanical relays suffer from slow response speed, easy contact erosion, and short mechanical lifespan. They are also prone to arcing and electromagnetic interference during switching, failing to meet the application requirements of high reliability and long lifespan. Therefore, a low-loss startup surge suppression method is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a low-loss start-up surge suppression method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, a low-loss initiation surge suppression method is provided, comprising the following steps: S1. Collect the equipment load status and current limiting device temperature before the electrical equipment starts, and at the same time obtain the historical start data of the electrical equipment. Classify the historical start data into status types based on the equipment load status and the current limiting device temperature. S2. Based on the historical startup data of each state type, perform startup surge risk analysis to determine the startup surge risk corresponding to each state type, and simultaneously combine the startup surge risk corresponding to each state type to set the risk level and divide the risk surge range. S3. For high-risk levels, the protection circuit module of the electrical equipment will disconnect the protection until the state of the electrical equipment is reduced to a non-high-risk level. S4. For non-high-risk levels, generate starting current curves for various types of electrical equipment based on historical startup data, and set switching conditions for the current limiting circuit module and bypass circuit module of the electrical equipment according to the starting current curves. S5. Based on the risk level and the confidence level of the starting current curve, set the deviation threshold, obtain the real-time current curve, compare the difference between the real-time current curve and the starting current curve, and correct the starting current curve generated in S4 based on the difference data until the real-time current curve reaches the switching condition, and set the switching time for the current limiting circuit module and the bypass circuit module.

[0006] As a further improvement to this technical solution, in S1, the no-load current and the current real-time load current of the equipment are collected by the current transformer installed at the incoming end of the electrical equipment, and the real-time load rate of the equipment is calculated. At the same time, the real-time voltage value of the power supply bus is collected by the voltage transformer. The final equipment load status is determined by combining the real-time load rate and the deviation of the power supply voltage. An NTC thermistor temperature sensor is attached to the heat dissipation surface of the current limiting device to collect the surface temperature of each current limiting device in real time, and the maximum value of the temperature of all current limiting devices is taken as the current temperature of the current limiting device.

[0007] As a further improvement to this technical solution, in step S1, the storage cloud of the electrical equipment is connected, and all complete startup records of the electrical equipment are extracted from the storage cloud as historical startup data; The equipment load status is divided into multiple levels according to the load rate from low to high, and the current limiting device temperature is divided into multiple levels according to the temperature from low to high. The levels of the two dimensions are randomly combined to obtain multiple startup status types. Then, the historical startup data is matched according to the status type to obtain the historical startup data corresponding to each status type.

[0008] As a further improvement to this technical solution, in step S2, the average peak value of surge current, the average surge duration, and the surge failure rate of historical startup data corresponding to each state type are statistically analyzed, and the comprehensive surge risk value of that state type is obtained by weighted calculation. The risk level is set for the state type based on the calculated comprehensive surge risk value, thereby classifying different state types into high-risk, medium-risk, and low-risk levels. The higher the overall surge risk value, the higher the risk level. Conversely, the lower the overall surge risk value, the lower the risk level.

[0009] As a further improvement to this technical solution, in S2, the maximum and minimum values ​​of the device load state and the current limiting device temperature of the state type are extracted respectively, and the unrecorded state type is analyzed in the interval composed of the maximum and minimum values ​​to obtain the unrecorded state types in the interval, thereby simulating and supplementing the unrecorded state types. In addition, the risk level of the simulated supplementary state types is set by combining the recorded state types and corresponding surge risk values, so that the state types and risk levels cover the range. Among them, the simulated supplementary status types should prioritize those with close numerical distances and high risk levels for status classification.

[0010] As a further improvement to this technical solution, in step S3, the real-time status type of the current electrical equipment before startup is obtained, and the status level of the real-time status type is determined. When it is determined that the real-time status type of the current electrical equipment before startup belongs to the high-risk level, the protection circuit module will disconnect the protection, cut off the main power supply circuit of the electrical equipment, and prohibit the electrical equipment from continuing to perform operations. After the protection trips, the system continuously acquires the real-time status of the electrical equipment before startup and re-determines the status type based on the real-time status. When it is determined that the current equipment status has been reduced to a non-high-risk level, the protection tripping status is automatically lifted, allowing the electrical equipment to re-initiate a startup request.

[0011] As a further improvement to this technical solution, in S4, when it is determined that the real-time state type before the current electrical equipment is started does not belong to the high-risk level, the historical current waveform data of successful start-up in all historical start-up data under the real-time state type is extracted, and all waveforms are time-aligned with the time when the start command is issued as a unified time reference point. Arithmetic average filtering is used to eliminate random noise in the waveforms and generate the standard start-up current curve corresponding to the state type. The standard startup current curve contains data on the change of current over time from the start of startup to the completion of startup. The point at which the current value drops to 1.2 times the rated current of the electrical equipment is located on the generated standard starting current curve. This point is set as the reference switching condition for the current limiting circuit module of the power equipment to disconnect and the bypass circuit module to close.

[0012] As a further improvement to this technical solution, in S5, the confidence level of the startup current curve is the ratio of the number of successful startup records used to generate the curve to the total number of successful startup records for this state type. The higher the ratio, the higher the confidence level; Conversely, the lower the ratio, the lower the confidence level; The deviation threshold is equal to the base deviation threshold multiplied by one, minus the confidence level, and then multiplied by the corresponding risk level. The higher the risk level, the smaller the deviation threshold; The lower the risk level, the larger the deviation threshold; After the electrical equipment is started, the real-time current curve is acquired, and the difference between the real-time current curve and the starting current curve is compared. The current difference between the real-time current curve and the starting current curve at the same time is calculated point by point to obtain the point-by-point difference data sequence. When the current difference exceeds the set deviation threshold for three consecutive moments, the standard starting current curve is dynamically corrected using the sliding weighted average method. The correction coefficient is the average of the ratio of the real-time current to the standard current for the most recent five moments. The corrected curve serves as the basis for subsequent comparison and switching. When the real-time current value drops to 1.2 times the rated current of the electrical equipment and the fluctuation range of three consecutive moments does not exceed the deviation threshold, it is determined that the switching condition has been met. Immediately, a disconnection command is sent to the current limiting circuit module, and a closing command is sent to the bypass circuit module to complete the seamless switching of the main circuit from the current limiting mode to the normal operation mode. If the current difference exceeds the set deviation threshold for three consecutive moments, and the real-time current value exceeds 1.2 times the rated current of the electrical equipment, the protection circuit module will disconnect the circuit.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In this low-loss startup surge suppression method, a dual-loop architecture of current limiting circuit and bypass circuit is set up. After startup, the main circuit is immediately switched to the bypass circuit made of pure copper material, and the current limiting circuit is completely shut down. There is no additional power loss caused by any series impedance, which completely solves the problem of continuous heat generation and low energy efficiency caused by long-term series connection of traditional current limiting components. At the same time, a standard startup current curve is generated based on historical successful startup data to accurately locate the optimal switching time, minimize the working time of the current limiting circuit, and reduce the power loss during startup to the minimum. There is no need to configure additional high-power heat dissipation devices, which helps to reduce equipment size and production costs.

[0014] 2. This low-loss startup surge suppression method comprehensively collects real-time parameters from multiple dimensions, such as equipment load rate, power supply bus voltage deviation, and current-limiting device temperature, to construct a two-dimensional state type matrix for fine-grained classification of startup conditions. Based on historical startup data, it statistically analyzes surge current peak value, duration, and fault occurrence rate to quantify and calculate the comprehensive surge risk value. Differentiated control strategies are adopted for different risk levels, solving the problem of poor adaptability of traditional fixed parameter schemes. For high-risk conditions, a pre-judgment active protection mechanism is adopted to cut off the main power supply circuit before power-on, avoiding device damage caused by surge impact from the source. For non-high-risk conditions, the suppression parameters are dynamically adjusted to achieve the optimal balance between surge suppression effect and operating loss, effectively adapting to startup requirements under different loads, different power grid environments, and different temperature conditions. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a low-loss start-up surge suppression method according to the present invention. Detailed Implementation

[0016] 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 embodiments of the present invention, and not all embodiments. 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.

[0017] Please see Figure 1 As shown, the purpose of this embodiment is to provide a low-loss surge suppression method, including the following steps: S1. Collect the equipment load status and current limiting device temperature before the electrical equipment starts, and at the same time obtain the historical start data of the electrical equipment. Classify the historical start data into status types based on the equipment load status and the current limiting device temperature. In S1, the no-load current and the current real-time load current of the equipment are collected by the current transformer installed at the incoming end of the electrical equipment, and the real-time load rate of the equipment is calculated. At the same time, the real-time voltage value of the power supply bus is collected by the voltage transformer. The final equipment load status is determined by combining the real-time load rate and the deviation of the power supply voltage. First, the equipment load status is collected. High-precision current transformers and voltage transformers are installed in the main incoming circuit of the electrical equipment.

[0018] The current transformer continuously collects two sets of current data at a millisecond-level sampling frequency: one set is the no-load reference current calibrated at the factory, and the other set is the real-time operating current at the instant before the equipment starts.

[0019] By comparing these two sets of current data, the actual load rate of the equipment can be calculated.

[0020] At the same time, the voltage transformer synchronously collects the real-time voltage value of the power supply bus and calculates the deviation between the current voltage and the rated voltage of the equipment.

[0021] The final equipment load status is determined by combining two parameters: real-time load rate and power supply voltage deviation.

[0022] A high-precision NTC thermistor temperature sensor is mounted on the core heat dissipation surface of each core current-limiting device (including power switching transistors, current-limiting resistors, thermistors, etc.) involved in surge suppression. The sensor collects the surface temperature data of each current-limiting device in real time at the same frequency as the current sampling, and automatically selects the maximum value among all collected temperatures as the current current-limiting device temperature of the entire surge suppression circuit. The current limiting capability and impact resistance of current limiting devices decrease non-linearly with increasing temperature, and the device with the highest temperature is the weakest link in the performance of the entire suppression circuit.

[0023] An NTC thermistor temperature sensor is attached to the heat dissipation surface of the current limiting device to collect the surface temperature of each current limiting device in real time, and the maximum value of the temperature of all current limiting devices is taken as the current temperature of the current limiting device.

[0024] In S1, the storage cloud of the electrical equipment is connected, and all complete startup records of the electrical equipment are extracted from the storage cloud as historical startup data. By connecting to the dedicated cloud storage platform of the electrical equipment through an encrypted industrial communication protocol, the system extracts all complete startup records of the equipment since it was put into operation from the cloud database as historical startup data. This includes the precise time of startup, the equipment load rate just before startup, the power supply bus voltage, the surface temperature of each current limiting device, the peak surge current during startup, the surge duration, and whether the startup was successfully completed.

[0025] The equipment load status is divided into multiple levels according to the load rate from low to high, and the current limiting device temperature is divided into multiple levels according to the temperature from low to high. The levels of the two dimensions are randomly combined to obtain multiple startup status types. Then, historical startup data is matched according to the status type to obtain the historical startup data corresponding to each status type. The steps are as follows: The equipment load status is divided into multiple continuous and non-overlapping level intervals according to the load rate from low to high. At the same time, the temperature of the current limiting device is also divided into the same number of continuous and non-overlapping level intervals according to the load rate from low to high. The load rate level and temperature level are combined one-to-one to form a two-dimensional state type matrix. All extracted historical startup data are matched one by one to the corresponding state type in a two-dimensional matrix based on the load rate and current-limiting device temperature recorded before startup, thus forming a unique historical startup dataset for each state type.

[0026] S2. Based on the historical startup data of each state type, perform startup surge risk analysis to determine the startup surge risk corresponding to each state type, and simultaneously combine the startup surge risk corresponding to each state type to set the risk level and divide the risk surge range. In S2, the average peak surge current, average surge duration, and surge failure rate of historical startup data corresponding to each state type are statistically analyzed, and the comprehensive surge risk value of that state type is obtained by weighted calculation. The peak value of the surge current is extracted by taking the maximum surge current value recorded during each successful startup under this state type and calculating the average value of all values. The average surge duration is calculated by extracting the total time from the appearance of the surge current to its return to the rated current during each successful startup process under this state type, and then calculating the average level of all durations. Surge failure rate: Count the number of times the protection circuit is activated, the startup fails or the device is damaged due to surge impact in all startup records under this state type, and calculate the proportion of the total number of startups under this state type. For industrial-grade high-reliability equipment, increase the weight of surge failure rate; for consumer electronics equipment, increase the weight of surge current peak value; for equipment with frequent start-stop cycles, increase the weight of surge duration. The three statistical indicators for each state type are converted according to a pre-defined level of importance, and the results of the three conversions are then summarized to obtain the comprehensive surge risk value that uniquely corresponds to that state type. The overall surge risk value is a quantitative expression of the overall hazard of surges under a given working condition. The higher the value, the higher the surge risk under that working condition.

[0027] The risk level is set for the state type based on the calculated comprehensive surge risk value, thereby classifying different state types into high-risk, medium-risk, and low-risk levels. Low risk level: Surge impacts at this level are completely within the safe tolerance range of the device and will not cause any damage to the equipment or affect the service life of the device. Medium risk level: Surge impacts at this level will not cause immediate damage to the equipment, but repeated occurrences over a long period of time will accelerate the aging of components and shorten the overall service life of the equipment. High-risk level: Surge impacts at this level are highly likely to cause device breakdown, burnout, or equipment startup failure, posing a serious safety hazard. The higher the overall surge risk value, the higher the risk level. Conversely, the lower the overall surge risk value, the lower the risk level.

[0028] In S2, the maximum and minimum values ​​of the device load state and current limiting device temperature of the state type are extracted respectively, and the unrecorded state type is analyzed in the interval composed of the maximum and minimum values ​​to obtain the unrecorded state types in the interval, thereby simulating and supplementing the unrecorded state types. Extract the maximum and minimum levels of equipment load rate and the maximum and minimum levels of current limiting device temperature from the generated two-dimensional state matrix to determine the entire operating condition range of the equipment during normal operation. Then, traverse all state types within the range and filter out unrecorded state types that have no historical startup records. For each unrecorded state type, among the recorded state types, find the neighboring state type with the smallest sum of load rate level difference and temperature level difference. If there are multiple neighboring state types at the same distance, select the one with the highest risk level and assign its risk level to the unrecorded state type.

[0029] In addition, the risk level of the simulated supplementary state types is set by combining the recorded state types and corresponding surge risk values, so that the state types and risk levels cover the range. Among them, the simulated supplementary status types should prioritize those with close numerical distances and high risk levels for status classification.

[0030] S3. For high-risk levels, the protection circuit module of the electrical equipment will disconnect the protection until the state of the electrical equipment is reduced to a non-high-risk level. When electrical equipment receives a start command, it should not start immediately, but should first be tested via S3; In S3, the real-time status type of the current electrical equipment before startup is obtained (by using S1 at the same sampling frequency as normal monitoring, the current real-time load rate of the equipment, the power supply bus voltage, and the surface temperature of all current limiting devices are collected synchronously), and the status level of the real-time status type is determined. When it is determined that the real-time status type of the current electrical equipment before startup belongs to the high-risk level, the protection circuit module will disconnect the protection, cut off the main power supply circuit of the electrical equipment, and prohibit the electrical equipment from continuing to perform operations. Based on the collected real-time parameters, the S2 quickly determines the status type and risk level corresponding to the current startup condition; When the risk level corresponding to the current startup condition is determined to be high risk, a protection disconnect command is immediately sent to the protection circuit module. At the same time, the main circuit startup relay of the equipment is locked, all subsequent power-on operation requests are blocked, and the equipment is prohibited from continuing to execute the startup process. The protection circuit module uses a contactless solid-state circuit breaker as the actuating element, which is connected in series in the main power supply circuit of the equipment. After receiving the disconnection command, the solid-state circuit breaker completes the disconnection of the main power supply circuit in microseconds. The disconnection process is free of electric arc and mechanical impact, and will not generate additional electromagnetic interference.

[0031] After the protection trips, the control circuit and data acquisition circuit of the equipment remain powered normally.

[0032] After the protection trips, the system continuously acquires the real-time status of the electrical equipment before startup and re-determines the status type based on the real-time status. When it is determined that the current equipment status has been reduced to a non-high-risk level, the protection tripping status is automatically lifted, allowing the electrical equipment to re-initiate a startup request.

[0033] When the risk level of the current operating condition is determined to have dropped to medium or low risk in a series of consecutive cyclic assessments, the protection release operation is automatically executed. A closing command is sent to the protection circuit module to restore the power supply path of the main power supply circuit. At the same time, the lock on the main circuit start relay is released, allowing the equipment to re-initiate the start request. S4. For non-high-risk levels, generate starting current curves for various types of electrical equipment based on historical startup data, and set switching conditions for the current limiting circuit module and bypass circuit module of the electrical equipment according to the starting current curves. After completing the pre-start safety verification in step S3 and determining that the current start-up condition is not at a high-risk level, immediately proceed to the standard start-up current curve generation process. In S4, when it is determined that the real-time status type of the current electrical equipment before startup does not belong to the high-risk level, the historical current waveform data of successful startup is extracted from all historical startup data under the real-time status type. The time of the startup command is used as a unified time reference point to align all waveforms in time. Arithmetic average filtering is used to eliminate random noise in the waveforms and generate the standard startup current curve corresponding to the status type. Extract all historical startup records under the current status type, and retain only historical startup records that have a complete startup process, have not triggered any protection actions, and have been successfully completed. Completely exclude startup failure records and abnormal records caused by power grid anomalies, load changes, human intervention, etc. Extract complete startup current waveform data from all filtered successful startup records. Each current waveform contains full-time current sampling data from the moment the startup command is issued to the moment the device enters steady-state operation. Use the precise moment the startup command is issued as the unified time reference point for all waveforms and align all historical current waveforms on the time axis. After completing the time alignment of all waveforms, the system uses the arithmetic mean filtering method to fuse all aligned historical current waveforms and generate the standard starting current curve corresponding to the current state type. On a unified time axis, starting from zero, at the same time interval as the sampling frequency, the current values ​​corresponding to all historical waveforms at each time point are taken sequentially, the average level of these current values ​​is calculated, and the average value is used as the current value of the standard startup current curve at that time point. This operation is repeated until the entire time interval from startup to steady-state operation is covered. The standard startup current curve contains data on the change of current over time from the start of startup to the completion of startup. The point at which the current value drops to 1.2 times the rated current of the electrical equipment is located on the generated standard starting current curve. This point is set as the reference switching condition for the current limiting circuit module of the power equipment to disconnect and the bypass circuit module to close.

[0034] On the generated standard starting current curve, the reference switching time point is located to obtain the rated current parameters of the electrical equipment. Then, starting from the starting point of the standard curve, the curve is traversed backward along the time axis to find the time point when the current value on the curve first drops to 1.2 times the rated current of the equipment.

[0035] This time point is set as the reference switching condition for the current limiting circuit module to disconnect and the bypass circuit module to close during this startup process. This reference switching condition is dynamic, and the standard startup current curves corresponding to different state types are different, so the reference switching time points will also be different.

[0036] S5. Based on the risk level and the confidence level of the starting current curve, set the deviation threshold, obtain the real-time current curve, compare the difference between the real-time current curve and the starting current curve, and correct the starting current curve generated in S4 based on the difference data until the real-time current curve reaches the switching condition, and set the switching time for the current limiting circuit module and the bypass circuit module.

[0037] In S5, the confidence level of the startup current curve is the ratio of the number of successful startup records used to generate the curve to the total number of successful startup records for this state type. The higher the ratio, the higher the confidence level; Conversely, the lower the ratio, the lower the confidence level; The deviation threshold is equal to the base deviation threshold multiplied by one, minus the confidence level, and then multiplied by the corresponding risk level. The higher the risk level, the smaller the deviation threshold; The lower the risk level, the larger the deviation threshold; After the electrical equipment is started, the real-time current curve is acquired, and the difference between the real-time current curve and the starting current curve is compared. The current difference between the real-time current curve and the starting current curve at the same time is calculated point by point to obtain the point-by-point difference data sequence. A power-on command is sent to the main circuit, and the electrical equipment officially enters the startup process. The current limiting circuit module starts working according to the preset logic to suppress the startup inrush current. At the same time, the current transformer at the incoming end collects the current data of the main circuit in real time at a frequency that is exactly the same as the sampling frequency of the standard curve, and generates the real-time current curve for this startup. The real-time current curve is compared point by point with the standard starting current curve. On a unified time axis, each new real-time current data point is immediately compared with the current value of the standard curve at the same time, and the difference between the two is calculated to form a point-by-point difference data sequence. When the current difference exceeds the set deviation threshold for three consecutive moments, the standard starting current curve is dynamically corrected using the sliding weighted average method. The correction coefficient is the average of the ratio of the real-time current to the standard current for the most recent five moments. The corrected curve serves as the basis for subsequent comparison and switching. When the real-time current value drops to 1.2 times the rated current of the electrical equipment and the fluctuation range of three consecutive moments does not exceed the deviation threshold, it is determined that the switching condition has been met. Immediately, a disconnection command is sent to the current limiting circuit module, and a closing command is sent to the bypass circuit module to complete the seamless switching of the main circuit from the current limiting mode to the normal operation mode. If the current difference exceeds the set deviation threshold for three consecutive moments, and the real-time current value exceeds 1.2 times the rated current of the electrical equipment, the protection circuit module will disconnect the circuit.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-loss initiation surge suppression method, characterized in that: Includes the following steps: S1. Collect the equipment load status and current limiting device temperature before the electrical equipment starts, and at the same time obtain the historical start data of the electrical equipment. Classify the historical start data into status types based on the equipment load status and the current limiting device temperature. S2. Based on the historical startup data of each state type, perform startup surge risk analysis to determine the startup surge risk corresponding to each state type, and simultaneously combine the startup surge risk corresponding to each state type to set the risk level and divide the risk surge range. S3. For high-risk levels, the protection circuit module of the electrical equipment will disconnect the protection until the state of the electrical equipment is reduced to a non-high-risk level. S4. For non-high-risk levels, generate starting current curves for various types of electrical equipment based on historical startup data, and set switching conditions for the current limiting circuit module and bypass circuit module of the electrical equipment according to the starting current curves. S5. Based on the risk level and the confidence level of the starting current curve, set the deviation threshold, obtain the real-time current curve, compare the difference between the real-time current curve and the starting current curve, and correct the starting current curve generated in S4 based on the difference data until the real-time current curve reaches the switching condition, and set the switching time for the current limiting circuit module and the bypass circuit module.

2. The low-loss start-up surge suppression method according to claim 1, characterized in that: In S1, the no-load current and the current real-time load current of the equipment are collected by the current transformer installed at the incoming end of the electrical equipment, and the real-time load rate of the equipment is calculated. At the same time, the real-time voltage value of the power supply bus is collected by the voltage transformer. The final equipment load status is determined by combining the real-time load rate and the power supply voltage deviation. An NTC thermistor temperature sensor is attached to the heat dissipation surface of the current limiting device to collect the surface temperature of each current limiting device in real time, and the maximum value of the temperature of all current limiting devices is taken as the current temperature of the current limiting device.

3. The low-loss start-up surge suppression method according to claim 1, characterized in that: In step S1, the storage cloud of the electrical equipment is connected, and all complete startup records of the electrical equipment are extracted from the storage cloud as historical startup data. The equipment load status is divided into multiple levels according to the load rate from low to high, and the current limiting device temperature is divided into multiple levels according to the temperature from low to high. The levels of the two dimensions are randomly combined to obtain multiple startup status types. Then, the historical startup data is matched according to the status type to obtain the historical startup data corresponding to each status type.

4. The low-loss start-up surge suppression method according to claim 1, characterized in that: In S2, the average peak value of surge current, the average surge duration, and the surge failure rate of historical startup data corresponding to each state type are statistically analyzed, and the comprehensive surge risk value of the state type is obtained by weighted calculation. The risk level is set for the state type based on the calculated comprehensive surge risk value, thereby classifying different state types into high-risk, medium-risk, and low-risk levels. The higher the overall surge risk value, the higher the risk level. Conversely, the lower the overall surge risk value, the lower the risk level.

5. The low-loss start-up surge suppression method according to claim 1, characterized in that: In S2, the maximum and minimum values ​​of the device load state and the current limiting device temperature of the state type are extracted respectively, and the unrecorded state type is analyzed in the interval composed of the maximum and minimum values ​​to obtain the unrecorded state types in the interval, thereby simulating and supplementing the unrecorded state types. In addition, the risk level of the simulated supplementary state types is set by combining the recorded state types and corresponding surge risk values, so that the state types and risk levels cover the range. Among them, the simulated supplementary status types should prioritize those with close numerical distances and high risk levels for status classification.

6. The low-loss start-up surge suppression method according to claim 1, characterized in that: In step S3, the real-time status type of the current electrical equipment before startup is obtained, and the status level of the real-time status type is determined. When it is determined that the real-time status type of the current electrical equipment before startup belongs to the high-risk level, the protection circuit module will disconnect the protection, cut off the main power supply circuit of the electrical equipment, and prohibit the electrical equipment from continuing to perform operations. After the protection trips, the system continuously acquires the real-time status of the electrical equipment before startup and re-determines the status type based on the real-time status. When it is determined that the current equipment status has been reduced to a non-high-risk level, the protection tripping status is automatically lifted, allowing the electrical equipment to re-initiate a startup request.

7. The low-loss start-up surge suppression method according to claim 1, characterized in that: In S4, when it is determined that the real-time state type of the current electrical equipment before startup does not belong to the high-risk level, the historical current waveform data of successful startup is extracted from all historical startup data under the real-time state type. The time of the startup command is issued as a unified time reference point to align all waveforms in time. Arithmetic average filtering is used to eliminate random noise in the waveforms and generate the standard startup current curve corresponding to the state type. The standard startup current curve contains data on the change of current over time from the start of startup to the completion of startup. The point at which the current value drops to 1.2 times the rated current of the electrical equipment is located on the generated standard starting current curve. This point is set as the reference switching condition for the current limiting circuit module of the power equipment to disconnect and the bypass circuit module to close.

8. The low-loss start-up surge suppression method according to claim 1, characterized in that: In S5, the confidence level of the startup current curve is the ratio of the number of successful startup records used to generate the curve to the total number of successful startup records for this state type. The higher the ratio, the higher the confidence level; Conversely, the lower the ratio, the lower the confidence level; The deviation threshold is equal to the base deviation threshold multiplied by one, minus the confidence level, and then multiplied by the corresponding risk level. The higher the risk level, the smaller the deviation threshold; The lower the risk level, the larger the deviation threshold; After the electrical equipment is started, the real-time current curve is acquired, and the difference between the real-time current curve and the starting current curve is compared. The current difference between the real-time current curve and the starting current curve at the same time is calculated point by point to obtain the point-by-point difference data sequence. When the current difference exceeds the set deviation threshold for three consecutive moments, the standard starting current curve is dynamically corrected using the sliding weighted average method. The correction coefficient is the average of the ratio of the real-time current to the standard current for the most recent five moments. The corrected curve serves as the basis for subsequent comparison and switching. When the real-time current value drops to 1.2 times the rated current of the electrical equipment and the fluctuation range of three consecutive moments does not exceed the deviation threshold, it is determined that the switching condition has been met. Immediately, a disconnection command is sent to the current limiting circuit module, and a closing command is sent to the bypass circuit module to complete the seamless switching of the main circuit from the current limiting mode to the normal operation mode. If the current difference exceeds the set deviation threshold for three consecutive moments, and the real-time current value exceeds 1.2 times the rated current of the electrical equipment, the protection circuit module will disconnect the circuit.

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