Method for leakage protection action alarm based on intelligent circuit breaker
By using the dynamic gain adjustment, load classification, and graded tripping control of intelligent circuit breakers, the problem of malfunction of traditional leakage protection devices under load fluctuations and complex environmental conditions is solved, achieving efficient and safe leakage protection in different power consumption scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGZHOU QIAN ZHONGZHI CONSTR MANAGEMENT CO LTD
- Filing Date
- 2025-02-24
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional leakage current protection devices are prone to malfunction under load fluctuations and complex environments, cannot adapt to the needs of different power usage scenarios, and cannot distinguish between transient and continuous faults, affecting the reliability and stability of the system.
The system employs an intelligent circuit breaker, which uses a zero-sequence coil to collect leakage current signals for dynamic gain adjustment and noise filtering. Combined with a microcontroller, it performs load classification, uses a multi-objective optimization algorithm to generate dynamic protection thresholds, and executes a graded tripping control strategy.
It enables flexible adjustment of leakage protection sensitivity under different operating conditions, reduces false alarm rate and action delay time, and improves system safety and stability.
Smart Images
Figure CN120073609B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of circuit breaker technology, and in particular to a leakage current protection alarm method based on a smart circuit breaker. Background Technology
[0002] In electrical systems, residual current circuit breaker (RCCB) is one of the key technologies for ensuring safe operation. Traditional RCCBs typically employ a single tripping mechanism, immediately disconnecting the circuit upon detecting a leakage current signal to prevent accidents such as electrical fires or personal injury. However, this single tripping mechanism has certain limitations in practical applications. First, due to large load fluctuations or complex environmental conditions, traditional RCCBs are prone to false tripping, frequently disconnecting the circuit and affecting normal power supply. Second, fixed-threshold RCCB mechanisms cannot adapt to the needs of different power usage scenarios, resulting in insufficient protection in some cases and oversensitivity in others, increasing the false alarm rate. Furthermore, traditional RCCBs, after detecting a leakage current signal, often cannot distinguish between transient and persistent faults, leading to unnecessary downtime and affecting the reliability and stability of the system.
[0003] With the increasing complexity of power systems and the diversification of load types, traditional leakage current protection mechanisms are no longer sufficient to meet the needs of modern electrical systems. Especially in temporary power supply scenarios, the fluctuating and nonlinear characteristics of loads make the detection and processing of leakage current signals more complex. Therefore, there is an urgent need for a leakage current protection method that can dynamically adjust the protection threshold according to actual operating conditions, reduce false trips, and improve protection accuracy. Summary of the Invention
[0004] In view of the above-mentioned prior art, the present invention provides a leakage current protection alarm method based on a smart circuit breaker, which mainly solves the technical problems existing in the background art.
[0005] To achieve the above objectives, the technical solution of this invention is implemented as follows:
[0006] A leakage current protection alarm method based on a smart circuit breaker, the alarm method comprising the following steps:
[0007] The leakage current signal of the main circuit is acquired by a zero-sequence coil, and the leakage current signal is dynamically gained and noise filtered to generate a preprocessed signal.
[0008] The preprocessed signal is subjected to frequency band filtering to extract leakage current characteristic signals within a preset frequency band, and the effective value of leakage current is obtained based on the leakage current characteristic signals.
[0009] Based on the power signal of the temporary power consumption scenario, the microcontroller unit obtains load classification;
[0010] Based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The dynamic protection threshold is used to adjust the leakage protection sensitivity in real time.
[0011] When the effective value of leakage current exceeds the dynamic protection threshold, a graded tripping control strategy is executed.
[0012] Optionally, based on the power signal of the temporary power consumption scenario, the microcontroller unit obtains load classification, specifically including: acquiring the three-phase current signal under leakage current scenario, and calculating the current harmonic distortion rate (THD) and fundamental power factor (PF) through fast Fourier transform. If THD < 8%, PF > 0.95, and current fluctuation standard deviation < 5%, then the load of the temporary power consumption scenario is a steady-state load; if THD ≥ 8%, PF ≤ 0.95, and there is a peak / mean ratio > 3, then the load of the temporary power consumption scenario is a dynamic load; if THD > 15%, and there are multiple high-frequency harmonics, then the load of the temporary power consumption scenario is a nonlinear load.
[0013] Optionally, based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The multi-objective optimization algorithm is a Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including humidity compensation coefficient, harmonic suppression weight, and scene adaptive factor is constructed, and the optimization objectives are set as leakage false alarm rate and action delay time. The Pareto optimal solution set is solved iteratively, 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, obtaining the effective value of leakage current based on the leakage current characteristic signal specifically includes: performing a fast Fourier transform on the leakage current characteristic signal to obtain the effective value of leakage current.
[0015] Optionally, the graded tripping strategy includes: first-level tripping, which triggers a rapid pre-tripping action through the drive circuit to eliminate contact abnormalities; and second-level tripping, which, if the leakage current continues to exceed the limit, activates the magnetic latching relay to forcibly disconnect the main circuit.
[0016] Optionally, when the effective value of leakage current exceeds the dynamic protection threshold, the first-level trip is triggered first. The drive circuit on the trip unit realizes a slight movement of the contacts to achieve a rapid pre-trip action and eliminate contact abnormalities. After the first-level trip is triggered, a 15ms timing window is started. If the leakage current signal does not disappear within the window period, the second-level trip is triggered immediately, and the main circuit contacts are forcibly separated through another magnetic latching relay.
[0017] Optionally, the rapid pre-trip action specifically includes: driving the trip unit with a PWM signal to perform micro-vibration at a frequency of 5kHz to eliminate the oxide layer on the contacts, and monitoring the change in the contact resistance of the main circuit in real time. If the resistance value drops below the safety threshold, the secondary trip is suspended.
[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 up yellow. When the second-level trip is triggered, the load LED on the indicator light circuit lights up red. When the effective value of leakage current is lower than the dynamic protection threshold, the load LED on the indicator light circuit turns off.
[0019] The beneficial effects of this invention are as follows: By employing a multi-objective optimization algorithm, combined with load classification results and environmental parameters, a protection threshold is dynamically generated. This method overcomes the limitations of traditional fixed thresholds, enabling flexible adjustment of leakage protection sensitivity under different operating conditions, minimizing false alarm rates and action delays, thereby achieving intelligent dynamic protection. Based on power signals from temporary power consumption scenarios, the microcontroller unit classifies the load and, combined with environmental parameters, generates protection strategies adapted to different scenarios. This classification mechanism makes the protection strategy more targeted, effectively addressing the challenges posed by load fluctuations and environmental changes. The graded tripping mechanism reduces unnecessary downtime and impact on normal operation, while ensuring rapid response in severe fault conditions, thus improving system safety. Attached Figure Description
[0020] Figure 1 This is a flowchart illustrating the leakage current protection alarm method based on a smart circuit breaker in this application embodiment. Detailed Implementation
[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. In the following description, the expression "some embodiments" refers to 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, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.
[0023] It should be understood that the present invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Furthermore, the terminology used herein is intended only to describe particular embodiments and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.
[0024] It should also be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0025] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.
[0026] Please refer to the attached document. Figure 1 A leakage current protection alarm method based on a smart circuit breaker, the alarm method comprising the following steps:
[0027] S1. The leakage current signal of the main circuit is acquired through the zero-sequence coil, and the leakage current signal is dynamically gained and noise filtered to generate a preprocessed signal.
[0028] S2. Perform frequency band filtering on the preprocessed signal, extract leakage current characteristic signals within the preset frequency band, and obtain the effective value of leakage current based on the leakage current characteristic signals.
[0029] S3. Based on the power signal of the temporary power consumption scenario, the load classification is obtained through the microcontroller unit;
[0030] S4. Based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The dynamic protection threshold is used to adjust the leakage protection sensitivity in real time.
[0031] S5. When the effective value of leakage current exceeds the dynamic protection threshold, a graded tripping control strategy is executed.
[0032] Specifically, the leakage current protection alarm method based on a smart circuit breaker provided in this application acquires leakage current signals in the main circuit through a zero-sequence coil, and performs dynamic gain adjustment and noise filtering to generate a clearer and more reliable pre-processed signal. This process effectively reduces the impact of external interference on signal acquisition, ensuring the accuracy of subsequent analysis. By filtering the pre-processed signal by frequency band, leakage current characteristic signals within specific frequency bands are extracted, and the effective value of leakage current is calculated using Fast Fourier Transform. This method can accurately capture the core characteristics of leakage current signals, providing a scientific basis for subsequent judgment. Simultaneously, based on the power signals in temporary power supply scenarios, the microcontroller unit analyzes the three-phase current signals and combines parameters such as harmonic distortion rate (THD) and fundamental power factor (PF) to achieve load classification. This classification mechanism not only considers the steady-state characteristics of the load but also takes into account dynamic and nonlinear characteristics, making the protection strategy more targeted. The method in this application introduces a multi-objective optimization algorithm, combining load classification results and environmental parameters to dynamically generate protection thresholds. This method breaks through the limitations of traditional fixed thresholds, and can flexibly adjust the leakage protection sensitivity under different operating conditions, minimizing false alarm rate and action delay time. By iteratively solving the Pareto optimal solution set, it selects the parameter combination that best suits the current operating conditions, thereby achieving intelligent dynamic protection.
[0033] When the effective value of leakage current exceeds the dynamic protection threshold, the system executes a tiered tripping control strategy. This strategy attempts to repair the potential problem through primary tripping, and only executes secondary tripping if the fault cannot be resolved. This reduces unnecessary downtime and impact on normal operation. Secondary tripping, as the final safety measure, ensures that the main circuit is quickly disconnected if the leakage current continues to exceed the limit, effectively preventing serious accidents such as electrical fires or personal injury. This dual protection mechanism significantly improves system safety.
[0034] Furthermore, based on the power signal of the temporary power consumption scenario, the microcontroller unit obtains load classification, specifically including: acquiring the three-phase current signal under leakage current scenario, and calculating the current harmonic distortion rate (THD) and fundamental power factor (PF) through fast Fourier transform. If THD < 8%, PF > 0.95, and current fluctuation standard deviation < 5%, then the load of the temporary power consumption scenario is a steady-state load; if THD ≥ 8%, PF ≤ 0.95, and there is a peak / mean ratio > 3, then the load of the temporary power consumption scenario is a dynamic load; if THD > 15%, and there are multiple high-frequency harmonics, then the load of the temporary power consumption scenario is a nonlinear load.
[0035] In an optional implementation, based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The multi-objective optimization algorithm is a Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including humidity compensation coefficient, harmonic suppression weight, and scene adaptive factor is constructed, and the optimization objectives are set as leakage false alarm rate and action delay time. The Pareto optimal solution set is solved iteratively, and the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold.
[0036] The parameter space comprises a humidity compensation coefficient, harmonic suppression weights, and a scenario adaptive factor. These parameters reflect the impact of environmental conditions on leakage current protection, the degree of harmonic interference on signal detection, and the characteristic differences under different power usage scenarios. The humidity compensation coefficient is used to adjust the impact of insulation performance degradation caused by changes in air humidity on leakage current detection; the harmonic suppression weights are used to optimize high-frequency harmonic interference generated by nonlinear loads; and the scenario adaptive factor dynamically adjusts the sensitivity of the protection strategy based on the load classification results, such as steady-state load, dynamic load, or nonlinear load.
[0037] Next, the optimization objectives are set as the false alarm rate and the action delay time. The false alarm rate reflects the probability that the system will erroneously trigger protection actions under normal operating conditions, while the action delay time measures the time interval between detecting a leakage signal and actually executing a tripping action. These two optimization objectives are mutually restrictive: reducing the false alarm rate may require increasing the detection threshold, thereby increasing the action delay; conversely, shortening the action delay may require lowering the detection threshold, thereby increasing the false alarm rate. Therefore, a balance needs to be found between the two.
[0038] Subsequently, the Pareto optimal solution set is obtained through iteration. The Bayesian optimization algorithm uses a probabilistic model to model the parameter space, gradually approaching the optimal solution. In each iteration, the algorithm updates the model based on the currently known solution set and selects new candidate parameter combinations for evaluation. This iterative process can efficiently explore complex parameter spaces and quickly converge to a set of solutions that satisfy the optimization objective, i.e., 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, there may be a greater tendency to reduce the false alarm rate of leakage current to avoid frequent malfunctions caused by environmental factors; while in scenarios with extremely high safety requirements, there may be a greater emphasis on shortening the action delay time to ensure timely disconnection of faulty circuits.
[0040] Furthermore, the humidity compensation coefficient is defined as the correction strength of humidity on the attenuation of leakage current signal, with a value range of 0.1 to 2.0; the harmonic suppression weight is the proportion of interference suppression of the 3rd and 5th harmonics on the leakage current criterion, with a value range of 0 to 1; and the scenario adaptive factor can reflect the load fluctuation characteristics of temporary power use scenarios, with a value range of 0.5 to 1.5.
[0041] In one optional implementation, obtaining the effective value of leakage current based on the leakage current characteristic signal specifically includes: performing a fast Fourier transform on the leakage current characteristic signal to obtain the effective value of leakage current.
[0042] In one optional implementation, the tiered tripping strategy includes: a first-level tripping mechanism that triggers a rapid pre-tripping action via a drive circuit to eliminate contact abnormalities; and a second-level tripping mechanism that, if the leakage current continues to exceed the limit, activates a magnetic latching relay to forcibly disconnect the main circuit.
[0043] Specifically, when the effective value of leakage current exceeds the dynamic protection threshold, the first-level trip is triggered first. The drive circuit on the trip unit realizes a slight movement of the contacts to achieve a rapid pre-trip action and eliminate contact abnormalities. After the first-level trip is triggered, a 15ms timing window is started. If the leakage current signal does not disappear within the window period, the second-level trip is triggered immediately, and the main circuit contacts are forcibly separated through another magnetic latching relay.
[0044] Furthermore, the rapid pre-trip action specifically includes: driving the trip unit with a PWM signal to perform micro-vibration at a frequency of 5kHz to eliminate the oxide layer on the contacts, and monitoring the change in the contact resistance of the main circuit in real time. If the resistance value drops below the safety threshold, the secondary trip is suspended.
[0045] Furthermore, 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 up yellow. When the second-level trip is triggered, the load LED on the indicator light circuit lights up red. When the effective value of leakage current is lower than the dynamic protection threshold, the load LED on the indicator light circuit turns off.
[0046] 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 that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A leakage current protection alarm method based on an intelligent circuit breaker, characterized in that, The alarm method includes the following steps: The leakage current signal of the main circuit is acquired by a zero-sequence coil, and the leakage current signal is dynamically gained and noise filtered to generate a preprocessed signal. The preprocessed signal is subjected to frequency band filtering to extract leakage current characteristic signals within a preset frequency band, and the effective value of leakage current is obtained based on the leakage current characteristic signals. Based on the power signal of the temporary power consumption scenario, load classification is obtained through the microcontroller unit; Based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. 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, a graded tripping control strategy is executed; Based on the power signal of the temporary power consumption scenario, the microcontroller unit obtains load classification, specifically including: acquiring the three-phase current signal under leakage current scenario, and calculating the current harmonic distortion rate (THD) and fundamental power factor (PF) through fast Fourier transform. If THD < 8%, PF > 0.95, and current fluctuation standard deviation < 5%, then the load of the temporary power consumption scenario is a steady-state load; if THD ≥ 8%, PF ≤ 0.95, and there is a peak / mean ratio > 3, then the load of the temporary power consumption scenario is a dynamic load; if THD > 15%, and there are multiple high-frequency harmonics, then the load of the temporary power consumption scenario is a nonlinear load. Based on the load classification results and combined with environmental parameters, a dynamic protection threshold is generated through a multi-objective optimization algorithm. The multi-objective optimization algorithm is a Bayesian optimization algorithm. In the Bayesian optimization algorithm, a parameter space including humidity compensation coefficient, harmonic suppression weight, and scene adaptive factor is constructed, and the optimization objectives are set as leakage false alarm rate and action delay time. The Pareto optimal solution set is solved iteratively, and the parameter combination closest to the current weight distribution is selected from the Pareto optimal solution set as the dynamic protection threshold.
2. The leakage current protection alarm method based on a smart circuit breaker according to claim 1, characterized in that, Obtaining the effective value of leakage current based on leakage current characteristic signals specifically includes: performing Fast Fourier Transform on the leakage current characteristic signals to obtain the effective value of leakage current.
3. The leakage current protection alarm method based on a smart circuit breaker according to claim 2, characterized in that, The graded tripping control strategy includes: Level 1 tripping, which triggers a rapid pre-tripping action through the drive circuit to eliminate contact abnormalities; Level 2 tripping, which activates the magnetic latching relay to forcibly disconnect the main circuit if the leakage current continues to exceed the limit.
4. The leakage current protection alarm method based on a smart circuit breaker according to claim 3, characterized in that, When the effective value of leakage current exceeds the dynamic protection threshold, the first-level trip is triggered first. The drive circuit on the trip unit realizes a slight movement of the contacts to achieve a rapid pre-trip action and eliminate contact abnormalities. After the first-level trip is triggered, a 15ms timing window is started. If the leakage current signal does not disappear within the window period, the second-level trip is triggered immediately, and the main circuit contacts are forcibly separated through another magnetic latching relay.
5. The leakage current protection alarm method based on a smart circuit breaker according to claim 4, characterized in that, The rapid pre-trip action specifically includes: driving the trip unit with a PWM signal to perform micro-vibration at a frequency of 5kHz to eliminate the oxide layer on the contacts, and monitoring the change in the contact resistance of the main circuit in real time. If the resistance value drops below the safety threshold, the secondary trip is suspended.
6. The leakage current protection alarm method based on a smart circuit breaker according to claim 5, characterized in that, 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 up yellow. When the second-level trip is triggered, the load LED on the indicator light circuit lights up red. When the effective value of leakage current is lower than the dynamic protection threshold, the load LED on the indicator light circuit turns off.