Leakage protection action alarm method based on intelligent circuit breaker

Abstract

The invention relates to the technical field of circuit breakers, in particular to a leakage protection action alarm method based on an intelligent circuit breaker, and the alarm method comprises the following steps: collecting a leakage signal of a main loop through a zero-sequence coil, carrying out the dynamic gain adjustment and noise filtering processing of the leakage signal, and generating a preprocessing signal; performing frequency band screening on the preprocessed signal, extracting an electric leakage characteristic signal in a preset frequency band, and obtaining an electric leakage effective value based on the electric leakage characteristic signal; obtaining load classification through the microcontroller unit based on a power signal of a temporary power utilization scene; based on the load classification result, combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm, and the dynamic protection threshold is used for adjusting leakage protection sensitivity in real time; and when the electric leakage effective value exceeds the dynamic protection threshold value, executing a hierarchical tripping control strategy.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and particularly to a leakage protection action warning method based on an intelligent circuit breaker. Background Art

[0002] In an electrical system, leakage protection is one of the key technologies to ensure safe operation. Traditional leakage protection devices usually adopt a single tripping mechanism, that is, when a leakage signal is detected, the circuit is immediately cut off to prevent accidents such as electrical fires or personal injuries. However, this single tripping mechanism has certain limitations in practical applications. First, due to large load fluctuations or complex environmental conditions, traditional leakage protection devices are prone to false operations and frequently cut off the circuit, affecting normal power consumption. Second, the leakage protection mechanism with a fixed threshold cannot meet the requirements of different power usage scenarios, resulting in insufficient protection in some cases and being too sensitive in other cases, increasing the false alarm rate. In addition, after detecting a leakage signal, traditional leakage protection devices usually cannot distinguish between transient faults and persistent faults, resulting in unnecessary shutdowns and affecting the reliability and stability of the system.

[0003] With the increasing complexity of the power system and the diversification of load types, traditional leakage protection mechanisms have been difficult to meet the requirements of modern electrical systems. Especially in temporary power usage scenarios, the volatility and non-linear characteristics of loads make the detection and processing of leakage signals more complex. Therefore, there is an urgent need for a leakage protection method that can dynamically adjust the protection threshold according to the actual working conditions, reduce false operations, and improve the protection accuracy. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention aims to provide a leakage protection action warning method based on an intelligent circuit breaker, mainly to solve the technical problems existing in the above background art.

[0005] To achieve the above object, the technical solution of the embodiment of the present invention is realized as follows:

[0006] A leakage protection action warning method based on an intelligent circuit breaker, the warning method includes the following steps:

[0007] Collect the leakage signal of the main circuit through the zero-sequence coil, perform dynamic gain adjustment and noise filtering processing on the leakage signal to generate a preprocessed signal;

[0008] Perform frequency band screening on the preprocessed signal, extract the leakage characteristic signal within a preset frequency band, and obtain the effective leakage value based on the leakage characteristic signal;

[0009] Obtain the load classification through the microcontroller unit based on the power signal in the temporary power usage scenario;

[0010] Based on the load classification result, combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm, and the dynamic protection threshold is used to adjust the leakage protection sensitivity in real time;

[0011] When the leakage effective value exceeds the dynamic protection threshold, a hierarchical tripping control strategy is executed.

[0012] Optionally, based on the power signal in the temporary power usage scenario, the load classification is obtained through the microcontroller unit, specifically including: collecting the three-phase current signals in the leakage scenario, and calculating the current harmonic distortion rate THD and the fundamental power factor PF through fast Fourier transform. If THD < 8%, PF > 0.95, and the standard deviation of current fluctuation < 5%, the load in the temporary power usage scenario is a steady-state load; if THD ≥ 8%, PF ≤ 0.95, and there is a peak / mean ratio > 3, the load in the temporary power usage scenario is a dynamic load; if THD > 15% and there are multiple high-frequency harmonics, the load in the temporary power usage scenario is a non-linear load.

[0013] Optionally, based on the load classification result, combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. Among them, the multi-objective optimization algorithm is the Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including a humidity compensation coefficient, a harmonic suppression weight, and a scenario adaptation factor is constructed, and the optimization objectives are set as the leakage false alarm rate and the action delay time. The Pareto optimal solution set is iteratively solved, and the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold.

[0014] Optionally, the leakage effective value is obtained based on the leakage characteristic signal, specifically including: performing fast Fourier transform processing on the leakage characteristic signal to obtain the leakage effective value.

[0015] Optionally, the hierarchical tripping strategy includes: primary tripping, triggering a fast pre-tripping action through a drive circuit to eliminate contact abnormalities; secondary tripping, if the leakage persists and exceeds the limit, enabling a magnetic latching relay to forcibly cut off the main circuit.

[0016] Optionally, when the leakage effective value exceeds the dynamic protection threshold, the primary tripping is first triggered. The drive circuit on the tripping device realizes a slight movement of the contact to achieve a fast pre-tripping action and eliminate contact abnormalities. When the primary tripping is triggered, a 15 ms timing window is started. If the leakage signal has not disappeared within the window period, the secondary tripping is immediately triggered, and the main circuit contacts are forcibly separated through another magnetic latching relay.

[0017] Optionally, the fast pre-tripping action specifically includes: driving the tripping device through a PWM signal to perform micro-vibrations at a frequency of 5 kHz to eliminate the contact oxide layer, and real-time monitoring the change of the main circuit contact resistance. If the resistance value drops below the safety threshold, the secondary tripping is paused.

[0018] Optionally, an indicator light circuit is provided at the microcontroller unit. When the first-level trip is triggered, the load LED on the indicator light circuit lights yellow. When the second-level trip is triggered, the load LED on the indicator light circuit lights red. When the leakage effective value is lower than the dynamic protection threshold, the load LED on the indicator light circuit goes out.

[0019] The beneficial effects of the present invention are as follows: Through the multi-objective optimization algorithm, combined with the load classification results and environmental parameters, the protection threshold is dynamically generated. This method breaks through the limitations of traditional fixed thresholds, can flexibly adjust the leakage protection sensitivity under different working conditions, minimizes the false alarm rate and action delay time, and thus realizes intelligent dynamic protection; Based on the power signals in the temporary power usage scenario, the microcontroller unit classifies the loads and combines the environmental parameters to generate protection strategies adapted to different scenarios. This classification mechanism makes the protection strategy more targeted and can effectively cope with the challenges brought by load fluctuations and environmental changes; The hierarchical trip mechanism reduces unnecessary shutdowns and impacts on normal operation, while ensuring a rapid response in the event of a serious fault, improving the safety of the system. Description of the Drawings

[0020] Figure 1 It is a schematic flowchart of the leakage protection action warning method based on an intelligent circuit breaker in an embodiment of this application. Detailed Embodiments

[0021] The technical solution of the present invention will be further elaborated in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the specification of this invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. In the following description, the expression "some embodiments" is mentioned, which describes a subset of all possible embodiments. However, it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0022] In the following description, a large number of specific details are given to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known to the public are not described.

[0023] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. And the purpose of the terms used herein is only to describe specific embodiments and not to limit the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0024] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time. The terms "vertical", "horizontal", "inner", "outer", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0025] To thoroughly understand the present invention, detailed structures will be presented in the following description to illustrate the technical solutions proposed by the present invention. The optional embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention can also have other implementations.

[0026] Please refer to the attached Figure 1 , a leakage protection action warning method based on an intelligent circuit breaker, the warning method comprising the following steps:

[0027] S1. Collect the leakage signal of the main circuit through the zero-sequence coil, perform dynamic gain adjustment and noise filtering processing on the leakage signal, and generate a preprocessing signal;

[0028] S2. Perform frequency band screening on the preprocessing signal, extract the leakage characteristic signal within the preset frequency band, and obtain the leakage effective value based on the leakage characteristic signal;

[0029] S3. Obtain the load classification through the microcontroller unit based on the power signal of the temporary power usage scenario;

[0030] S4. Based on the load classification result, combine the environmental parameters, and generate a dynamic protection threshold through a multi-objective optimization algorithm, and the dynamic protection threshold is used to adjust the leakage protection sensitivity in real time;

[0031] S5. When the effective leakage current exceeds the dynamic protection threshold, a hierarchical tripping control strategy is executed.

[0032] Specifically, for the leakage protection action warning method based on an intelligent circuit breaker provided in this application, a leakage signal in the main circuit is collected through a zero-sequence coil, and dynamic gain adjustment and noise filtering processing are performed on it, thereby generating a clearer and more reliable preprocessed signal. This process effectively reduces the influence of external interference on signal collection and ensures the accuracy of subsequent analysis. By screening the frequency band of the preprocessed signal, the leakage characteristic signal within a specific frequency band is extracted, and the effective leakage current is calculated using the fast Fourier transform. This method can accurately capture the core characteristics of the leakage signal and provide a scientific basis for subsequent judgment. At the same time, based on the power signal in the temporary power usage scenario, the microcontroller unit classifies the load by analyzing the three-phase current signals and combining parameters such as the total harmonic distortion (THD) and fundamental power factor (PF). This classification mechanism not only considers the steady-state characteristics of the load but also takes into account the dynamic and non-linear characteristics, making the protection strategy more targeted. The method in this application introduces a multi-objective optimization algorithm, combines the load classification results and environmental parameters, and dynamically generates a protection threshold. This method breaks through the limitations of traditional fixed thresholds, can flexibly adjust the leakage protection sensitivity under different working conditions, and minimizes the false alarm rate and action delay time. By iteratively solving the Pareto optimal solution set, the parameter combination that best suits the current operating conditions is selected, thereby achieving intelligent dynamic protection.

[0033] When the effective leakage current exceeds the dynamic protection threshold, the system executes a hierarchical tripping control strategy. The hierarchical tripping strategy attempts to repair potential problems through primary tripping and only executes secondary tripping when it is confirmed that the fault cannot be resolved, thereby reducing unnecessary shutdowns and impacts on normal operation. As the final safety guarantee measure, secondary tripping ensures that the main circuit can be quickly cut off when the leakage problem persists and exceeds the limit, effectively preventing serious accidents such as electrical fires or personal injuries. This dual protection mechanism greatly improves the safety of the system.

[0034] Further, based on the power signal in the temporary power usage scenario, the load classification is obtained through the microcontroller unit, specifically including: collecting the three-phase current signals in the leakage scenario and calculating the current total harmonic distortion THD and fundamental power factor PF through the fast Fourier transform. If THD < 8%, PF > 0.95, and the standard deviation of current fluctuation < 5%, then the load in the temporary power usage scenario is a steady-state load; if THD ≥ 8%, PF ≤ 0.95, and there is a peak / mean ratio > 3, then the load in the temporary power usage scenario is a dynamic load; if THD > 15% and there are multiple high-frequency harmonics, then the load in the temporary power usage scenario is a non-linear load.

[0035] In an alternative embodiment, based on the load classification result and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The multi-objective optimization algorithm is the Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including a humidity compensation coefficient, a harmonic suppression weight, and a scenario adaptation factor is constructed, and the optimization objectives are set as the leakage false alarm rate and the action delay time. The Pareto optimal solution set is iteratively solved, and the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold.

[0036] A parameter space including a humidity compensation coefficient, a harmonic suppression weight, and a scenario adaptation factor. These parameters respectively reflect the influence of environmental conditions on leakage protection, the degree of interference of harmonic interference on signal detection, and the characteristic differences under different electricity consumption scenarios. The humidity compensation coefficient is used to adjust the influence of the decrease in insulation performance caused by the change in air humidity on leakage detection; the harmonic suppression weight optimizes the high-frequency harmonic interference generated by non-linear loads; the scenario adaptation factor dynamically adjusts the sensitivity of the protection strategy according to the load classification result, such as steady-state load, dynamic load, or non-linear load.

[0037] Next, the optimization objectives are set as the leakage false alarm rate and the action delay time. The leakage false alarm rate reflects the probability of the system wrongly triggering the protection action under normal operating conditions, while the action delay time measures the time interval from detecting the leakage signal to actually performing the tripping action. These two optimization objectives restrict each other: reducing the false alarm rate may require increasing the detection threshold, thereby increasing the action delay; while shortening the action delay may reduce the detection threshold, thus increasing the false alarm rate. Therefore, a balance needs to be found between the two.

[0038] Subsequently, the Pareto optimal solution set is iteratively solved. The Bayesian optimization algorithm uses a probability model to model the parameter space and gradually approaches the optimal solution. In each iteration process, the algorithm updates the model according to the currently known solution set and selects a new candidate parameter combination for evaluation. This iterative process can efficiently explore the complex parameter space and quickly converge to a set of solutions that meet the optimization objectives, that is, the Pareto optimal solution set.

[0039] Finally, the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold. This selection process fully considers the priority requirements under the current operating conditions. For example, in a high-humidity environment, it may be more inclined to reduce the leakage false alarm rate to avoid frequent false operations caused by environmental factors; while in a scenario with extremely high safety requirements, more attention may be paid to shortening the action delay time to ensure timely cutting off of the faulty circuit.

[0040] Further, the humidity compensation coefficient defines the correction intensity of humidity on the attenuation of the leakage current signal, with a value range of 0.1 to 2.0. The harmonic suppression weight controls the interference suppression ratio of the 3rd and 5th harmonics on the leakage current criterion, with a value range of 0 to 1. The scenario adaptation factor can reflect the load fluctuation characteristics of the temporary power usage scenario, with a value range of 0.5 to 1.5.

[0041] In an alternative embodiment, the leakage current effective value is obtained based on the leakage current characteristic signal, specifically including: performing a fast Fourier transform on the leakage current characteristic signal to obtain the leakage current effective value.

[0042] In an alternative embodiment, the hierarchical tripping strategy includes: primary tripping, triggering a fast pre-tripping action through a drive circuit to eliminate abnormal contacts; secondary tripping, if the leakage current continues to exceed the limit, enabling a magnetic latching relay to forcibly cut off the main circuit.

[0043] Specifically, when the leakage current effective value exceeds the dynamic protection threshold, the primary tripping is first triggered. The drive circuit on the tripping device causes a slight movement of the contacts to achieve the fast pre-tripping action and eliminate abnormal contacts. After the primary tripping is triggered, a 15 ms timing window is started. If the leakage current signal has not disappeared within the window period, the secondary tripping is immediately triggered, and the main circuit contacts are forcibly separated through another magnetic latching relay.

[0044] Further, the fast pre-tripping action specifically includes: driving the tripping device through a PWM signal to perform micro-amplitude vibration at a frequency of 5 kHz to eliminate the contact oxidation layer, and continuously monitoring the change in the main circuit contact resistance. If the resistance value drops below the safety threshold, the secondary tripping is paused.

[0045] Further, an indicator light circuit is provided at the microcontroller unit. When the primary tripping is triggered, the load LED on the indicator light circuit lights yellow. When the secondary tripping is triggered, the load LED on the indicator light circuit lights red. When the leakage current effective value is lower than the dynamic protection threshold, the load LED on the indicator light circuit goes off.

[0046] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. The protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A leakage protection action alarm method based on an intelligent circuit breaker, characterized in that: The alarm method comprises the following steps: The leakage signal of the main circuit is collected through the zero-sequence coil, and the leakage signal is dynamically gain adjusted and noise filtered to generate a preprocessing signal; Performing frequency band screening on the preprocessed signal, extracting a leakage characteristic signal within a preset frequency band, and obtaining a leakage effective value based on the leakage characteristic signal; Based on the power signal of the temporary power usage scenario, load classification is obtained by the microcontroller unit; Based on the load classification result and in combination with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm, and the dynamic protection threshold is used to adjust the leakage protection sensitivity in real time; When the effective value of leakage current exceeds the dynamic protection threshold, the hierarchical tripping control strategy is executed.

2. The leakage protection action alarm method based on intelligent circuit breaker according to claim 1 is characterized in that: Based on the power signal of the temporary power consumption scenario, the load classification is obtained through the microcontroller unit, specifically including: collecting the three-phase current signal under the leakage scenario, and calculating the current harmonic distortion rate THD and the fundamental power factor PF through fast Fourier transform. If THD is less than 8%, PF is greater than 0.95, and the current fluctuation standard deviation is less than 5%, then the load of the temporary power consumption scenario is a steady-state load; if THD is greater than or equal to 8%, PF is less than or equal to 0.95, and there is a peak / mean ratio greater than 3, then the load of the temporary power consumption scenario is a dynamic load; if THD is greater than 15% and there are multiple high-frequency harmonics, then the load of the temporary power consumption scenario is a nonlinear load.

3. The leakage protection action alarm method based on intelligent circuit breaker according to claim 2 is characterized in that: Based on the load classification result and in combination with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm, wherein the multi-objective optimization algorithm is a Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including a humidity compensation coefficient, a harmonic suppression weight, and a scene adaptation factor is constructed, and the optimization targets are set as leakage false alarm rate and action delay time, and the Pareto optimal solution set is iteratively solved, and the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold.

4. The leakage protection action alarm method based on intelligent circuit breaker according to claim 3 is characterized in that: Obtaining the leakage effective value based on the leakage characteristic signal specifically includes: performing fast Fourier transform processing on the leakage characteristic signal to obtain the leakage effective value.

5. The leakage protection action alarm method based on intelligent circuit breaker according to claim 4 is characterized in that: The hierarchical tripping strategy includes: first-level tripping, triggering a fast pre-tripping action through a drive circuit to eliminate contact abnormalities; second-level tripping, if the leakage current continues to exceed the limit, enabling the magnetic latching relay to forcibly cut off the main circuit.

6. The leakage protection action alarm method based on intelligent circuit breaker according to claim 5 is characterized in that: When the effective value of leakage exceeds the dynamic protection threshold, the first-level tripping is triggered first. The driving circuit on the tripper realizes slight movement of the contacts, implements rapid pre-tripping action, and eliminates contact abnormalities. When the first-level tripping is triggered, the 15ms timing window is started. If the leakage signal does not disappear within the window period, the second-level tripping is immediately triggered, and the main circuit contacts are forcibly separated through another magnetic latching relay.

7. The leakage protection action alarm method based on intelligent circuit breaker according to claim 6 is characterized in that: The fast pre-tripping action specifically includes: driving the releaser through a PWM signal, performing a slight vibration at a frequency of 5kHz, eliminating the contact oxide layer, and monitoring the change of the main circuit contact resistance in real time. If the resistance value drops below the safety threshold, the secondary tripping is suspended.

8. The leakage protection action alarm method based on intelligent circuit breaker according to claim 7 is characterized in that: An indicator light circuit is provided at the microcontroller unit. When the first-level trip is triggered, the load LED light on the indicator light circuit lights up yellow. When the second-level trip is triggered, the load LED light on the indicator light circuit lights up red. When the effective value of the leakage current is lower than the dynamic protection threshold, the load LED light on the indicator light circuit goes out.

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