Intelligent circuit breaker control method and system based on power carrier communication

Abstract

The application relates to the technical field of power carrier communication, in particular to a smart circuit breaker control method and system based on power carrier communication. The method periodically acquires a power line channel state through a carrier communication module, determines available frequency bands and selects a working frequency band, allocates address codes for each circuit breaker, encapsulates a configuration frame, broadcasts, completes link initialization, generates a data frame containing an operation code, a target address, a check code and a frequency band identifier in response to a control instruction, modulates the data frame to a power line transmission after error correction coding, demodulates and decodes a target circuit breaker to restore the data frame, compares and checks addresses, executes opening and closing operations after matching, and returns a state return frame. When an exception is executed, the current frequency band is removed and a frequency band is reselected to broadcast an updated configuration frame to rebuild the link, so that the reliability and anti-interference ability of the circuit breaker control are remarkably improved, and the communication link is adaptively stable.

Description

Technical Field

[0001] This invention relates to the field of power line carrier communication technology, and in particular to a smart circuit breaker control method and system based on power line carrier communication. Background Technology

[0002] As a core terminal device in the intelligent transformation of low-voltage distribution networks, the remote opening and closing control function of intelligent circuit breakers typically relies on a communication system. In existing technologies, remote control operation of intelligent circuit breakers mainly employs power line carrier communication, utilizing existing low-voltage power lines as the signal transmission medium. This eliminates the need for additional communication cables, offering inherent advantages such as convenient construction and wide coverage. In conventional implementations, the system pre-sets a fixed carrier communication frequency band for each circuit breaker and uses static address encoding and a master-slave polling mechanism to issue control commands and transmit status information. Communication parameters are fixed at the factory or only initialized once when the equipment is powered on, without dynamic adjustment during subsequent operation. This approach, due to its simplicity and low cost, was widely used in early intelligent building and factory power distribution systems.

[0003] Power line channels are not designed for communication. Their impedance characteristics vary drastically with the connected load, and various nonlinear electrical appliances continuously introduce broadband noise and random pulse interference. Once a fixed frequency band encounters strong narrowband interference or frequency-selective fading, the carrier signal will be significantly attenuated or even submerged, leading to the loss of control data frames or a surge in bit error rate. Because the system lacks real-time assessment methods for channel quality and cannot actively migrate to a frequency band with a better signal-to-noise ratio, the communication link will remain in a low-quality state for a long time. This directly leads to serious consequences such as unreliable issuance of remote control tripping commands, circuit breaker failure to operate, or malfunction, posing a threat to the safety of the power supply system.

[0004] Another significant drawback is the lack of autonomous recovery capability in communication links. When interference causes continuous degradation of the established operating frequency band, conventional systems lack a logical mechanism to trigger link reconstruction, typically relying on manual on-site intervention, such as reconfiguring communication parameters or replacing concentrator equipment. Furthermore, static address allocation schemes require power outages and parameter rewriting when the number of circuit breakers increases or the topology changes, resulting in high maintenance costs and an inability to adapt to the increasingly frequent structural adjustments required by the distribution network. In this state, the duration of communication interruptions and troubleshooting efficiency are entirely limited by the speed of manual response, making it difficult to meet the needs of application scenarios with high power supply continuity requirements. Summary of the Invention

[0005] This invention provides a smart circuit breaker control method and system based on power line carrier communication, which can solve the problems in the prior art.

[0006] A first aspect of the present invention provides a smart circuit breaker control method based on power line carrier communication, comprising: The system periodically sends carrier probe signals to the power line to obtain channel attenuation and noise distribution of multiple preset frequency bands. It identifies the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands. It obtains the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive probe cycles. It calculates the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, selects the frequency band with the highest score as the current working frequency band, assigns address codes to each smart circuit breaker, and broadcasts configuration frames. In response to control commands, a data frame is generated. The data frame is then concatenated after being encoded with a first symbol length and then encoded with a second symbol length. The first symbol length is shorter than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frame is then transmitted via carrier modulation. The target circuit breaker demodulates, decodes, and restores the data frame, and performs address comparison and verification. When the verification is successful, the most recently confirmed status is read from the status register. If the operation type indicated by the opcode field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and the status register is updated. The status information is then assembled into a status receipt frame and sent back. When the status feedback frame indicates an abnormal action execution, it is determined whether the status information contains a mechanical fault identifier or a communication layer abnormality. If it is determined to be a communication layer abnormality, a hysteresis judgment is performed on the current working frequency band, and the frequency band that meets the rejection conditions is removed and a new working frequency band is selected.

[0007] Carrier probe signals are periodically sent to the power line to obtain channel attenuation and noise distribution in multiple preset frequency bands. Frequency bands with a signal-to-noise ratio (SNR) higher than a preset noise threshold are identified as the set of usable frequency bands. The linear fitting slope of the SNR for each usable frequency band over multiple consecutive probe periods is obtained. A frequency band selection score is calculated using a weighted average of the linear fitting slope and the current SNR, and the frequency band with the highest score is selected as the current working frequency band, including: After each carrier probe signal transmission and acquisition of channel attenuation and noise distribution, the ratio of the number of currently available frequency bands in the available frequency band set to the total capacity of the available frequency band set is calculated as the frequency band availability rate. The next probe signal transmission interval is determined based on the frequency band availability rate change trend of the most recent consecutive probe cycles. When the frequency band availability rate continues to decline and the decline exceeds the preset deterioration threshold, the transmission interval is shortened by the first step length to increase the detection frequency. When the frequency band availability rate remains stable and the signal-to-noise ratio fluctuation of each available frequency band is lower than the preset stability threshold, the transmission interval is extended by the second step length to reduce the detection frequency. When selecting the current working frequency band from the available frequency band set, the linear fitting slope of the signal-to-noise ratio (SNR) value of each available frequency band over the most recent consecutive detection periods is obtained as the SNR change slope. A positive selection bias is assigned to available frequency bands with a positive SNR change slope and the largest positive value, and a negative selection bias is assigned to available frequency bands with a negative SNR change slope. The frequency band selection score is calculated by weighting the available frequency band's SNR change slope with the currently measured SNR, and the available frequency band with the highest frequency band selection score is selected as the current working frequency band.

[0008] Assign address codes to each smart circuit breaker and broadcast configuration frames, including: The address codes of each smart circuit breaker on the power line are organized in a segmented structure. The address code is composed of the communication area segment, the device identification segment, and the verification segment, which are concatenated first by first. The communication area segment is determined based on the relative physical location of the smart circuit breaker in the power line access topology. The device identification segment is the fixed-length device identification value obtained by hash mapping operation after the unique identifier burned into the smart circuit breaker at the factory. The verification segment is generated by the communication area segment and the device identification segment according to the preset coding rules after bitwise XOR operation and cyclic shift operation. Each time the current operating frequency band is updated and a configuration frame is broadcast via carrier signal, the index information of the current operating frequency band after the update and the timestamp of the update are written together into the configuration register stored locally by each smart circuit breaker. After receiving the carrier signal, each smart circuit breaker demodulates the carrier frequency obtained by demodulation and looks up the latest frequency band index recorded in the local configuration register. The latest frequency band index obtained by looking up the latest frequency band index is compared bit by bit with the frequency band index value carried by the frequency band identifier field in the data frame to complete the consistency verification. If the verification fails, the data frame is discarded and a frequency band synchronization failure flag is returned.

[0009] Carrier modulation transmission includes: The data frame is divided into multiple first symbol groups with a preset first symbol length. The first coding algorithm is used to perform first error correction coding for narrowband continuous noise interference on each first symbol group. The check bit generated by the first error correction coding is used as the first check unit and appended to the tail of the corresponding first symbol group to form a first error correction code block. The first coding algorithm adopts low redundancy group error correction coding. All first error correction code blocks are concatenated end to end in the order of their generation to form a first coding stream. The first coding stream is then re-divided into multiple second code block groups with a preset second code length. Each second code block is then subjected to second error correction coding for burst impulse noise interference using a second coding algorithm. The check bit generated by the second error correction coding is appended to the end of the corresponding second code block as a second check unit to form a second error correction code block. The length of the first code block is shorter than the length of the second code block, and the error correction capability of the second coding algorithm is stronger than that of the first coding algorithm. All the second error correction code blocks are connected end to end to form the code stream to be modulated. The code stream to be modulated is then modulated by a single carrier at the carrier frequency corresponding to the current working frequency band and injected into the power line for transmission via a coupling circuit.

[0010] Assemble the status information into a status receipt frame and send it back, including: Read the most recently confirmed status of the circuit breaker from the status register stored locally in the target circuit breaker, after the most recent confirmation to the control terminal via a status acknowledgment frame. If the operation type indicated by the operation code field is opening and the most recently confirmed status is opening, or the operation type indicated by the operation code field is closing and the most recently confirmed status is closing, then determine that the current control command is a redundant operation request, suppress the generation of drive signals for the actuator, and return a status acknowledgment frame containing a redundant operation confirmation flag to the control terminal through the current operating frequency band. If the operation type indicated by the operation code field is inconsistent with the most recently confirmed status, a drive pulse signal corresponding to the operation type is generated to drive the actuator to perform the corresponding opening or closing action. After the drive pulse signal is sent, the travel position signal of the actuator is collected by the limit switch to determine the actual status of the circuit breaker after the action. The actual status of the circuit breaker is written into the status register to overwrite and update the most recently confirmed status. The operation code field contained in this control command and the updated most recently confirmed status are filled into the status receipt frame according to the preset frame structure, and the assembled status receipt frame is sent to the control terminal using the carrier of the current operating frequency band.

[0011] When a status feedback frame indicates an abnormal action execution, the system determines whether the abnormality is due to a communication layer or a device layer based on whether the status information contains a mechanical fault identifier. If it is determined to be a communication layer abnormality, a hysteresis check is performed on the current operating frequency band. Frequency bands that meet the rejection criteria are removed, and a new operating frequency band is selected, including: Based on the status information carried in the status receipt frame, execution anomalies are classified according to the source of the fault. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information does not contain a mechanical fault identification code, it is determined to be a communication layer link anomaly. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information contains a mechanical fault identification code, it is determined to be a device layer execution anomaly. When a communication layer link is determined to be abnormal, a hysteresis determination is performed on the current working frequency band. If the proportion of sampling points with a signal-to-noise ratio below the preset removal threshold in the continuous sliding window exceeds the first preset proportion, it is determined that the removal condition is met. The current working frequency band that meets the removal condition is removed from the available frequency band set, and a frequency band is reselected from the remaining available frequency bands in the available frequency band set. The frequency band with the highest score is selected as the new current working frequency band.

[0012] A second aspect of the present invention provides an intelligent circuit breaker control system based on power line carrier communication, comprising: The initialization unit is used to periodically send carrier detection signals to the power line, obtain the channel attenuation and noise distribution of multiple preset frequency bands, determine the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands, obtain the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive detection periods, calculate the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, select the frequency band with the highest score as the current working frequency band, assign address codes to each smart circuit breaker and broadcast configuration frames; The modulation and transmission unit is used to generate data frames in response to control commands, perform first error correction encoding on the data frames with a first symbol length, concatenate the first and last data frames, and then perform second error correction encoding with a second symbol length. The first symbol length is less than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frames are then transmitted via carrier modulation. The comparison and verification unit is used to demodulate and decode the target circuit breaker to restore the data frame and perform address comparison and verification. The feedback unit reads the most recently confirmed status from the status register when the verification is successful. If the operation type indicated by the operation code field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and update the status register. The status information is then assembled into a status feedback frame and sent back. The frequency band selection unit, similar to the status feedback frame indicating an abnormal action execution, determines whether the status information contains a mechanical fault identifier as a communication layer abnormality or an equipment layer abnormality. If it is determined to be a communication layer abnormality, it performs a hysteresis judgment on the current working frequency band, removes the frequency bands that meet the rejection conditions, and reselects a working frequency band.

[0013] A third aspect of the present invention provides an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the aforementioned method.

[0014] A fourth aspect of the present invention provides a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the aforementioned method.

[0015] The beneficial effects are as follows: In complex power line environments, carrier communication quality is significantly affected by line impedance, load noise, and multipath fading. This method periodically probes the channel attenuation and noise distribution of multiple preset frequency bands, constructs a set of usable frequency bands with a signal-to-noise ratio higher than a preset threshold, and dynamically selects the current operating frequency band. This effectively avoids strong narrowband interference and frequency-selective fading, ensuring that the communication channel is always in a high-quality state. It reduces the bit error rate and packet loss rate of data frame transmission from the source, improves the real-time performance and success rate of control commands, and provides a robust communication physical layer foundation for reliable control of smart circuit breakers.

[0016] Each smart circuit breaker connected to the power line is assigned a unique address code, and the current operating frequency band and address code are encapsulated into a configuration frame for broadcast. This standardizes the initialization of the communication link, giving multiple circuit breakers a clear and independent logical identity on the same power line medium, avoiding address conflicts and data addressing ambiguities during multi-device communication. After receiving the carrier signal and demodulating and decoding it to restore the data frame, the target circuit breaker compares the target address field with the locally pre-stored address. Simultaneously, a cyclic redundancy check field verifies the data integrity. Only when the address matches and the verification is correct is the opening or closing operation performed. This effectively prevents malfunctions of unrelated devices and interference from false commands caused by noise, significantly improving the uniqueness and error resistance of the action commands.

[0017] The data frame contains an opcode field, a destination address field, a cyclic redundancy check field, and a frequency band identifier field. After error correction coding, it is transmitted using carrier modulation of the current operating frequency band. This multi-field combination structure facilitates the receiver's rapid and accurate interpretation of the control intent. The error correction coding endows the data frame with a certain error correction capability, enabling the recovery of the original information even in the event of some sudden interference in the channel, thus enhancing the robustness of data transmission. After the actuator completes its action, the status information and the opcode field are assembled into a status feedback frame and transmitted back, forming a control closed loop, allowing the master station to promptly grasp the execution result. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the intelligent circuit breaker control method based on power line carrier communication according to an embodiment of the present invention. Figure 2This is a trend chart of signal-to-noise ratio in each frequency band according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating the redundancy operation determination and action execution process of an intelligent circuit breaker according to an embodiment of the present invention. Figure 4 This is a statistical chart showing the execution results of the circuit breaker in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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.

[0020] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0021] Figure 1 This is a flowchart illustrating the intelligent circuit breaker control method based on power line carrier communication according to an embodiment of the present invention.

[0022] Intelligent circuit breaker control methods based on power line carrier communication include: The system periodically sends carrier probe signals to the power line to obtain channel attenuation and noise distribution of multiple preset frequency bands. It identifies the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands. It obtains the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive probe cycles. It calculates the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, selects the frequency band with the highest score as the current working frequency band, assigns address codes to each smart circuit breaker, and broadcasts configuration frames. In response to control commands, a data frame is generated. The data frame is then concatenated after being encoded with a first symbol length and then encoded with a second symbol length. The first symbol length is shorter than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frame is then transmitted via carrier modulation. The target circuit breaker demodulates, decodes, and restores the data frame, and performs address comparison and verification. When the verification is successful, the most recently confirmed status is read from the status register. If the operation type indicated by the opcode field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and the status register is updated. The status information is then assembled into a status receipt frame and sent back. When the status feedback frame indicates an abnormal action execution, it is determined whether the status information contains a mechanical fault identifier or a communication layer abnormality. If it is determined to be a communication layer abnormality, a hysteresis judgment is performed on the current working frequency band, and the frequency band that meets the rejection conditions is removed and a new working frequency band is selected.

[0023] In one optional implementation, a carrier probe signal is periodically sent to the power line to obtain channel attenuation and noise distribution of multiple preset frequency bands. Frequency bands with a signal-to-noise ratio (SNR) higher than a preset noise threshold are identified as a set of usable frequency bands. The linear fitting slope of the SNR for each usable frequency band over multiple consecutive probe periods is obtained. A frequency band selection score is calculated using a weighted average of the linear fitting slope and the current SNR, and the frequency band with the highest score is selected as the current working frequency band. This includes: After each carrier probe signal transmission and acquisition of channel attenuation and noise distribution, the ratio of the number of currently available frequency bands in the available frequency band set to the total capacity of the available frequency band set is calculated as the frequency band availability rate. The next probe signal transmission interval is determined based on the frequency band availability rate change trend of the most recent consecutive probe cycles. When the frequency band availability rate continues to decline and the decline exceeds the preset deterioration threshold, the transmission interval is shortened by the first step length to increase the detection frequency. When the frequency band availability rate remains stable and the signal-to-noise ratio fluctuation of each available frequency band is lower than the preset stability threshold, the transmission interval is extended by the second step length to reduce the detection frequency. When selecting the current working frequency band from the available frequency band set, the linear fitting slope of the signal-to-noise ratio (SNR) value of each available frequency band over the most recent consecutive detection periods is obtained as the SNR change slope. A positive selection bias is assigned to available frequency bands with a positive SNR change slope and the largest positive value, and a negative selection bias is assigned to available frequency bands with a negative SNR change slope. The frequency band selection score is calculated by weighting the available frequency band's SNR change slope with the currently measured SNR, and the available frequency band with the highest frequency band selection score is selected as the current working frequency band.

[0024] like Figure 2 As shown, the method includes: The figure shows the signal-to-noise ratio (SNR) changes of five preset frequency bands over eight consecutive detection cycles. The data shows that the SNR of the 1.8MHz band continuously decreased from 22dB in the T-7 cycle to the current 8dB, a drop of 14dB, exhibiting a clear deterioration trend. This band no longer meets communication quality requirements in actual operation and should be removed from the available band set. The 2.4MHz band steadily increased from 20dB to 29dB, with the largest upward slope, indicating continuous improvement in channel quality. Based on the characteristic that the SNR change slope is positive and has the largest value, the system assigns the highest positive selection bias to this band. Combining the current instantaneous SNR with the slope of change, a weighted band selection score is calculated, ultimately selecting 2.4MHz as the current operating frequency band. The SNRs of the remaining bands, such as 1.2MHz, 3.2MHz, and 4.0MHz, remained stable around 25.5dB, 24.5dB, and 12.0dB, respectively. The 4.0MHz band consistently remained below the preset noise threshold and was therefore unusable. After acquiring this data through periodic probing, the system calculates the frequency band availability and dynamically adjusts the transmission interval of the next probing signal based on the availability trend over multiple consecutive periods. When the frequency band availability continuously declines and exceeds the degradation threshold, the interval is shortened to increase the probing frequency; conversely, the interval is lengthened to reduce overhead. This mechanism ensures that the operating frequency band is always selected from those with high signal-to-noise ratios and a positive trend, effectively avoiding narrowband interference and frequency-selective fading.

[0025] After transmitting a carrier probe signal and acquiring current power line channel attenuation and noise distribution data, the ratio between the number of available frequency bands that meet the signal-to-noise ratio requirements and the pre-set total capacity of the set is calculated. This ratio is defined as the frequency band availability rate. Let the total capacity of the available frequency band set be... The number of currently available frequency bands is The frequency band availability rate for This ratio reflects the overall quality of the current power line channel environment and is the core basis for dynamically adjusting the detection cycle.

[0026] To avoid sluggish response during periods of drastic channel fluctuations and wasted communication resources during periods of channel stability, an adaptive detection interval adjustment mechanism based on the frequency band availability trend is introduced. The frequency band availability sequence obtained from several recent consecutive detection cycles (e.g., five consecutive detection cycles) is recorded, and trend analysis is performed on this sequence. When the frequency band availability shows a continuous downward trend over several consecutive cycles, and the decrease between adjacent cycles exceeds a preset deterioration threshold, it is determined that the current channel environment is rapidly deteriorating, requiring higher frequency acquisition of channel state information for timely adjustment of the operating frequency band. At this point, the current detection signal transmission interval is shortened by a first step length, increasing the detection frequency and ensuring that the frequency band switching decision can be completed before channel conditions deteriorate further. The specific value of the first step length can be pre-configured based on the typical rate of change of power line interference in the system deployment scenario, typically set as a certain proportion of the current interval to avoid excessive adjustment that would cause the detection signal to frequently occupy channel bandwidth.

[0027] When the frequency band availability remains stable over multiple consecutive detection cycles, and the signal-to-noise ratio fluctuation of all available frequency bands in the available frequency band set is lower than the preset stability threshold within that time window, the current channel environment is determined to be in a stable state, and high-frequency detection is unnecessary. At this point, the transmission interval is extended by the second step size to reduce the detection frequency, decrease interference from the carrier detection signal to normal communication data transmission, and reduce the power consumption of the carrier communication module. The second step size and the first step size can be set to different values; typically, the second step size is smaller than the first step size. This ensures a smoother extension of the interval as the channel stabilizes, avoiding missing sudden changes in the channel state due to excessively rapid reduction in the detection frequency. Upper and lower limits should be set for adjusting the transmission interval to prevent excessively short intervals from causing detection signal congestion or excessively long intervals from causing severe lag in channel state perception.

[0028] When selecting the current operating frequency band from the set of available frequency bands, not only are the instantaneous signal-to-noise ratios (SNRs) of each available frequency band within the current detection period considered, but the changing trend of the SNR of each frequency band over time is also comprehensively analyzed. Specifically, for each available frequency band in the set of available frequency bands, the SNR numerical sequence measured in the most recent consecutive detection periods of that frequency band is extracted. This sequence is then linearly fitted with time as the independent variable, and the slope of the resulting fitted line is the slope of the SNR change for that frequency band, denoted as . . A positive value indicates that the signal-to-noise ratio of this frequency band has been increasing recently, and the channel quality is improving; A negative value indicates that the signal-to-noise ratio of that frequency band is decreasing and the channel quality is deteriorating.

[0029] slope of signal-to-noise ratio change Assign a positive selection bias to the available frequency bands with positive values, in all In the frequency band where the value is positive, The frequency band with the highest value receives the highest positive bias weight, indicating that the channel quality improvement trend in this band is most significant. Prioritizing this band can result in a longer stable communication time window. (Regarding the slope of the signal-to-noise ratio change...) By assigning a negative selection bias to available frequency bands with negative values, the probability of them being selected is reduced, thus avoiding the need for frequent switching of operating frequency bands due to a continuous decline in channel quality after selection, which would affect the stability of the communication link.

[0030] The frequency band selection score is calculated by comprehensively considering two dimensions: the slope of the signal-to-noise ratio (SNR) change and the instantaneous SNR measured during the current detection cycle. Let the measured SNR of a certain available frequency band be... The slope of the signal-to-noise ratio change is The positive selection bias weighting coefficient is The instantaneous signal-to-noise ratio weighting coefficient is Then the frequency band selection score for that frequency band. Calculate as follows: .for The frequency band with negative values Take a larger positive value so that the negative slope is balanced. It produces a significant inhibitory effect; for For frequency bands with positive values, the same applies. Positive contribution enhances its value. and The specific value can be configured according to the emphasis on communication stability and real-time channel quality in the actual application scenario. For example, in power distribution automation scenarios with extremely high requirements for communication reliability, the value can be appropriately increased. The increased proportion of these frequencies gives the trending frequency bands a greater competitive advantage.

[0031] Iterate through all available frequency bands in the available frequency band set and calculate the band selection score for each band. Select The available frequency band with the highest value is used as the current operating frequency band. If multiple frequency bands are available... When the values ​​are the same, the current instantaneous signal-to-noise ratio can be used. Prioritize higher frequencies to ensure current communication quality. After selecting the operating frequency band, encapsulate it together with the address codes of each smart circuit breaker in a configuration frame and broadcast it. Upon receiving the configuration frame, all smart circuit breakers connected to the power line update their locally stored operating frequency band parameters. Subsequent data frame transmissions and receptions are switched to the new operating frequency band, thus completing the frequency band update of the communication link.

[0032] The aforementioned adaptive detection interval mechanism and trend-aware frequency band selection mechanism work together to enable the entire communication link to maintain high communication quality when the power line channel environment changes dynamically, while reducing detection overhead when the channel is stable, thus achieving a balance between communication reliability and resource utilization efficiency.

[0033] In one alternative implementation, assigning address codes to each smart circuit breaker and broadcasting configuration frames includes: The address codes of each smart circuit breaker on the power line are organized in a segmented structure. The address code is composed of the communication area segment, the device identification segment, and the verification segment, which are concatenated first by first. The communication area segment is determined based on the relative physical location of the smart circuit breaker in the power line access topology. The device identification segment is the fixed-length device identification value obtained by hash mapping operation after the unique identifier burned into the smart circuit breaker at the factory. The verification segment is generated by the communication area segment and the device identification segment according to the preset coding rules after bitwise XOR operation and cyclic shift operation. Each time the current operating frequency band is updated and a configuration frame is broadcast via carrier signal, the index information of the current operating frequency band after the update and the timestamp of the update are written together into the configuration register stored locally by each smart circuit breaker. After receiving the carrier signal, each smart circuit breaker demodulates the carrier frequency obtained by demodulation and looks up the latest frequency band index recorded in the local configuration register. The latest frequency band index obtained by looking up the latest frequency band index is compared bit by bit with the frequency band index value carried by the frequency band identifier field in the data frame to complete the consistency verification. If the verification fails, the data frame is discarded and a frequency band synchronization failure flag is returned.

[0034] The segmented structure of the address code is fundamental to ensuring that each smart circuit breaker in the power line carrier communication network can be uniquely addressed. The address code consists of three parts: a communication area segment, a device identifier segment, and a check segment, sequentially concatenated first and second. The boundaries between these three segments are fixed, allowing the receiving end to directly extract the content of each segment based on its bit offset, without the need for additional separators. The communication area segment determines its corresponding area number value based on the smart circuit breaker's relative physical location within the power line access topology. The relative physical location refers to the node path number of each access point in the hierarchical tree after dividing the access points according to the power line branching direction, with the master control node as the root node. For example, the area number value of the communication area segment of the third access point on the first branch of the main line reflects the topological location information of "first branch, third node." When the power line network is expanded or its topology is adjusted, the communication area segment numbers of newly added nodes are redistributed according to the current topology, while the communication area segment numbers of existing nodes remain unchanged, thus ensuring the traceability of historical configuration records.

[0035] The generation of the device identifier segment relies on a unique identifier burned into the non-volatile memory of the smart circuit breaker at the factory. This unique identifier typically contains information such as the manufacturer's number, product model, batch number, and serial number, with a total length exceeding the bit width reserved for the device identifier segment in the address code. Therefore, a hash mapping operation is performed on the unique identifier, compressing and mapping the original identifier of arbitrary length into a fixed-length digest value. A predetermined number of bits is then extracted from this digest value as the device identifier value and filled into the device identifier segment. The selection of the hash mapping operation must balance collision probability and computational complexity: the number of devices connected in the same communication area segment is limited, and extracting a hash digest with a sufficient number of bits can control the collision probability within an acceptable range; simultaneously, the operation logic must be able to execute efficiently on the low-power microcontroller built into the circuit breaker to avoid affecting the device's power-on initialization speed due to excessive computational overhead. When a hash collision occurs with an extremely low probability, i.e., two devices in the same communication area segment have the same device identifier value, the area number of one device can be offset and adjusted manually to ensure that the complete address codes of the two devices remain unique.

[0036] The communication area segment and the corresponding bits of the device identifier segment are XORed bit by bit according to a preset encoding rule to obtain an intermediate result of the same length as the device identifier segment. If the number of bits in the communication area segment is less than that in the device identifier segment, the communication area segment is cyclically padded to the same length as the device identifier segment before the XOR operation is performed. A cyclic shift operation is performed on the intermediate result obtained in the first step. The shift direction and shift step size are specified by the preset encoding rule. The result after the shift is completed is the final content of the check segment. The purpose of the check segment is that after the receiving end extracts the address code, it can re-perform the bit-by-bit XOR and cyclic shift operation on the communication area segment and the device identifier segment according to the same preset encoding rule, compare the calculation result with the check segment, and if they are inconsistent, it is determined that a bit flip error has occurred in the address code during transmission. This completes a lightweight integrity verification before address comparison, reducing the probability of erroneous operation caused by noise interference.

[0037] Each time the current operating frequency band is updated and a configuration frame is broadcast via carrier signal, the updated operating frequency band index information and the timestamp of this update must be written together into the configuration register stored locally in each smart circuit breaker. The introduction of the timestamp solves the problem of cyclic reuse of frequency band index values ​​after multiple switches: if only the frequency band index is recorded without the timestamp, when the operating frequency band returns to a historical frequency band after multiple switches, the device cannot distinguish whether the current configuration frame is the latest frame of this switch or a replay frame from the past. After the timestamp and frequency band index are written together into the configuration register, the configuration register always stores a complete snapshot of the state at the time of the most recent successful reception of the configuration frame, including the frequency band index value selected for that switch and its corresponding timestamp.

[0038] Upon receiving a carrier signal, each smart circuit breaker first demodulates the signal, extracting the carrier frequency value used by the current carrier signal. Then, using this carrier frequency value as the lookup key, it performs a reverse lookup operation in the local configuration register to locate the latest frequency band index record corresponding to that carrier frequency. The logic for this reverse lookup is based on the fixed mapping relationship between the frequency band index recorded in the configuration register and the corresponding carrier frequency. This mapping relationship is sent along with the configuration frame during the communication link initialization phase and is persistently stored. If the demodulated carrier frequency does not have a corresponding record in the configuration register's mapping table, it indicates that the current signal is using a frequency band that has never been configured. In this case, the signal is discarded, a frequency band synchronization failure flag is returned, and the subsequent data frame parsing process is not initiated.

[0039] After obtaining the latest frequency band index through reverse lookup, this index value is compared bit by bit with the frequency band index value carried in the frequency band identifier field of the data frame to complete the consistency verification. Bit-by-bit comparison means aligning the binary representations of the two frequency band index values ​​bit by bit and checking each bit for consistency. Only when all bits are identical is the verification considered successful. The purpose of consistency verification is to prevent the following scenario: During the switching of operating frequency bands, a data frame remaining on the old frequency band may be received by a circuit breaker after the new frequency band configuration has taken effect due to propagation delay. In this case, the frequency band identifier field of the data frame still records the index value of the old frequency band, while the configuration register has been updated to the index value of the new frequency band. Bit-by-bit comparison will detect the inconsistency, thus discarding the expired data frame and preventing the circuit breaker from performing incorrect opening or closing actions based on expired instructions. If the verification fails, in addition to discarding the data frame, a frequency band synchronization failure flag must be returned to the upper-level control logic so that the control terminal can be aware that the circuit breaker is currently in a state of frequency band asynchrony, thereby triggering the process of rebroadcasting the configuration frame to ensure that the working frequency band information of all nodes in the network is restored to consistency.

[0040] The write operation to the configuration register must be atomic. During the carrier signal broadcast configuration frame, if the circuit breaker happens to be performing a tripping or closing action, electromagnetic interference from the actuator can interrupt the write operation to the configuration register, resulting in partially written dirty data. Therefore, the write operation to the configuration register employs a double-buffering mechanism: first write to the backup area, then switch the pointer. The new frequency band index and timestamp are first written to the backup register area. After the write is completed and verified by the checksum section, the read pointer is switched from the current area to the backup area. The read pointer switching operation is a single write operation, possessing atomicity at the microcontroller architecture level, thus avoiding interference from dirty data on consistency verification.

[0041] In one alternative implementation, carrier modulation transmission includes: The data frame is divided into multiple first symbol groups with a preset first symbol length. The first coding algorithm is used to perform first error correction coding for narrowband continuous noise interference on each first symbol group. The check bit generated by the first error correction coding is used as the first check unit and appended to the tail of the corresponding first symbol group to form a first error correction code block. The first coding algorithm adopts low redundancy group error correction coding. All first error correction code blocks are concatenated end to end in the order of their generation to form a first coding stream. The first coding stream is then re-divided into multiple second code block groups with a preset second code length. Each second code block is then subjected to second error correction coding for burst impulse noise interference using a second coding algorithm. The check bit generated by the second error correction coding is appended to the end of the corresponding second code block as a second check unit to form a second error correction code block. The length of the first code block is shorter than the length of the second code block, and the error correction capability of the second coding algorithm is stronger than that of the first coding algorithm. All the second error correction code blocks are connected end to end to form the code stream to be modulated. The code stream to be modulated is then modulated by a single carrier at the carrier frequency corresponding to the current working frequency band and injected into the power line for transmission via a coupling circuit.

[0042] During the modulation and transmission of data frames after error correction coding, the power line channel faces various types of noise interference. Two typical types of interference exist simultaneously on power lines: one is narrowband continuous noise introduced by persistent interference sources such as power grid harmonics and frequency converters. This noise has a concentrated spectrum and long duration, but its impact is usually limited to a few consecutive symbols. The other is sudden impulse noise caused by electrical equipment switching operations, lightning strikes, etc. This noise has an extremely short duration but a very large amplitude, often destroying a large number of consecutive symbols in a short period, causing sudden errors. For these two types of interference with vastly different characteristics, a single error correction coding strategy is insufficient to balance error correction efficiency and coding overhead. Therefore, a two-stage cascaded error correction coding mechanism is introduced to specifically address narrowband continuous noise and sudden impulse noise.

[0043] The first level of coding addresses narrowband continuous noise interference, dividing the data frame to be transmitted into a preset first symbol length. Divide into blocks, each Each symbol constitutes a first symbol block. A first coding algorithm is independently executed on each first symbol block. This algorithm employs low-redundancy block error correction coding, typically implemented as a variant of Hamming code or BCH code with smaller parameters. Low redundancy means that the number of parity bits appended to each first symbol block is relatively small, minimizing the impact of coding redundancy on the effective data transmission rate while ensuring a certain level of error correction capability. The parity bits generated by the first coding algorithm constitute the first parity check unit, which is appended to the end of the corresponding first symbol block, thus forming a complete first error-correcting code block. The length of the first error-correcting code block is... Adding the number of bits in the first check unit, let the number of bits in the first check unit be . The total length of each first error-correcting code block is then... Since errors caused by narrowband continuous noise are usually scattered within each symbol block, block error correction coding can effectively locate and correct such randomly distributed errors, while the selection of low redundancy keeps the overall coding efficiency at a high level.

[0044] After generating all the first error-correcting code blocks, they are concatenated end-to-end in the order they were generated to form a continuous first coded stream. The total length of the first coded stream is equal to the number of all first code symbol groups in the data frame and the length of a single first error-correcting code block. The product of. When entering the second-level encoding stage, with a preset second symbol length. The first encoded stream is re-divided into several blocks, resulting in several second symbol groups. It is important to note that the length of the first symbol... Less than the length of the second symbol This design is the core of the two-level coding mechanism: the first level of coding handles continuous noise at a smaller block granularity, while the second level of coding handles burst impulse noise at a larger block granularity. Since burst impulse noise can continuously destroy a large number of symbols in a short period of time, if coding with strong error correction capability is applied in units of larger symbol blocks, burst errors can be dispersed and absorbed in larger error correction code blocks, thereby effectively recovering the damaged data.

[0045] The second coding algorithm is executed independently for each second symbol block. The error correction capability of the second coding algorithm is stronger than that of the first coding algorithm; typical implementations include Reed-Solomon codes or BCH codes with large parameters. Reed-Solomon codes have a natural resistance to burst errors, and their error correction capability is measured in symbols, capable of correcting burst errors of multiple consecutive symbols, highly matching the destructive mode of burst impulse noise. The parity bits generated by the second coding algorithm constitute the second parity check unit, which is appended to the end of the corresponding second symbol block to form the second error-correcting code block. Let the number of bits in the second parity check unit be denoted as . Then the total length of each second error-correcting code block is Because the second coding algorithm has stronger error correction capabilities, it also has more additional check bits than the first check unit. However, this extra overhead is exchanged for effective resistance to sudden impulse noise, achieving a reasonable balance between coding redundancy and error correction capabilities overall.

[0046] The cascaded two-level coding structure provides data with two layers of protection during transmission: the inner layer (first level) protects against scattered random errors, while the outer layer (second level) protects against concentrated burst errors. At the receiving end, during decoding, the second error-correcting code block is first processed by reversing the second coding algorithm to correct concentrated errors caused by burst noise and recover the first coded stream; then, the first coded stream is processed according to the first symbol length... The data is re-divided into blocks, and the inverse process of the first encoding algorithm is performed on each first error-correcting code block to correct the dispersion errors caused by narrowband continuous noise, ultimately restoring the original data frame content. This outside-to-in decoding order corresponds to the inside-to-outside order during encoding, ensuring that the two-level error correction mechanism works synergistically.

[0047] After completing two levels of error correction coding, all second-level error correction code blocks are concatenated sequentially to form the modulated code stream. The modulated code stream is then modulated using a single carrier frequency corresponding to the current operating frequency band. Single-carrier modulation has low implementation complexity and good robustness to phase noise, making it suitable for the characteristics of power line channels. After modulation, the modulated signal is injected into the power line via a coupling circuit. The coupling circuit provides electrical isolation and impedance matching between the modulated signal and the power line, ensuring efficient injection of the carrier signal into the power line while preventing damage to communication equipment from the high voltage on the power line. The coupling circuit typically consists of an isolation transformer, filter capacitors, and an impedance matching network, with a bandwidth covering the current operating frequency band to ensure that the carrier signal does not experience significant amplitude attenuation or waveform distortion during injection. After injection into the power line, the signal propagates along the line to the receiving end at the target circuit breaker. The coupling circuit at the receiving end extracts the carrier signal, demodulates it, and performs two levels of decoding to reconstruct the original data frame, completing the entire encoding, modulation, and transmission process.

[0048] In one optional implementation, assembling the status information into a status receipt frame and transmitting it back includes: Read the most recently confirmed status of the circuit breaker from the status register stored locally in the target circuit breaker, after the most recent confirmation to the control terminal via a status acknowledgment frame. If the operation type indicated by the operation code field is opening and the most recently confirmed status is opening, or the operation type indicated by the operation code field is closing and the most recently confirmed status is closing, then determine that the current control command is a redundant operation request, suppress the generation of drive signals for the actuator, and return a status acknowledgment frame containing a redundant operation confirmation flag to the control terminal through the current operating frequency band. If the operation type indicated by the operation code field is inconsistent with the most recently confirmed status, a drive pulse signal corresponding to the operation type is generated to drive the actuator to perform the corresponding opening or closing action. After the drive pulse signal is sent, the travel position signal of the actuator is collected by the limit switch to determine the actual status of the circuit breaker after the action. The actual status of the circuit breaker is written into the status register to overwrite and update the most recently confirmed status. The operation code field contained in this control command and the updated most recently confirmed status are filled into the status receipt frame according to the preset frame structure, and the assembled status receipt frame is sent to the control terminal using the carrier of the current operating frequency band.

[0049] like Figure 3 As shown, the method includes: During the execution of opening or closing actions and the transmission of status confirmation frames, the first step is to read the most recently confirmed status stored in the target circuit breaker's local status register. This status register is a dedicated register field in the non-volatile storage area within the circuit breaker control unit. Its content stores the actual operating status of the circuit breaker, which was most recently successfully confirmed to the control terminal via a status confirmation frame, and its value is either open or closed. Each time a complete control process (including driving the actuator, transmitting the result via carrier wave, and receiving confirmation from the control terminal) is completed, the status register is updated to reflect the actual status after this action, thus continuously tracking the latest confirmed position of the circuit breaker.

[0050] After reading the most recently confirmed status, it is compared with the operation type indicated by the operation code field in the current data frame. If the operation type indicated by the operation code field is "open," and the most recently confirmed status recorded in the status register is also "open," it means that the circuit breaker is currently in the open position, and the status required by this control command is completely consistent with the actual status of the circuit breaker. Therefore, the control command is determined to be a redundant operation request. Similarly, if the operation type indicated by the operation code field is "close," and the most recently confirmed status is also "close," it is also determined to be a redundant operation request. The determination logic of redundant operation requests is based on the principle of state consistency: when the target status is the same as the currently confirmed status, repeatedly driving the actuator is not only meaningless but also causes unnecessary mechanical wear to the actuator. Therefore, it is necessary to actively suppress the generation of drive signals. After suppressing the drive signals, the circuit breaker control unit sends a status feedback frame to the control terminal through the current operating frequency band. This frame contains a redundant operation confirmation identifier to inform the control terminal that this command has been received and identified as a redundant request. The actual status of the circuit breaker has not changed, and the control terminal can determine that there is no need to resend the command or perform abnormal handling.

[0051] When the operation type indicated by the operation code field is inconsistent with the most recently confirmed status (i.e., the operation type is opening but the current confirmed status is closing, or the operation type is closing but the current confirmed status is opening), the normal operation execution process begins. The control unit generates a corresponding drive pulse signal based on the operation type. The drive pulse signal is a sequence of electrical pulses with specific voltage amplitude, duration, and polarity, corresponding to the excitation requirements of the opening or closing coil, respectively. For opening, the drive pulse signal energizes the opening coil, causing the latching mechanism of the actuator to release, releasing the spring's stored energy and causing the contacts to separate, completing the opening. For closing, the drive pulse signal energizes the closing coil, driving the actuator to press the contacts down and latch them into place, completing the closing. The duration of the drive pulse signal is pre-calibrated according to the actuator's rated operating time parameters to ensure that the coil is automatically de-energized after completing one full operation, avoiding overheating of the coil due to prolonged energization.

[0052] After the drive pulse signal is sent, the travel completion signal of the actuator needs to be collected through the limit switch to confirm whether the actuator has reached the target position. The limit switch is installed at the open and close completion points of the actuator. When the actuator moves to the corresponding position, the contact state of the limit switch changes, generating a travel completion signal. The control unit continuously polls the output status of the limit switch within a preset detection window after the drive pulse ends. If a travel completion signal corresponding to the operation type is received within the detection window (opening operation corresponds to the opening completion signal, and closing operation corresponds to the closing completion signal), the action is determined to be successful, and the actual state of the circuit breaker is determined to be the corresponding opening or closing state. If no valid travel completion signal is received after the detection window expires, the action is determined to be abnormal, and the actual state of the circuit breaker is recorded as abnormal. Regardless of whether the action is successful or not, the actual state of the circuit breaker determined this time is written to the status register to overwrite and update the most recently confirmed state, ensuring that the status register always reflects the latest confirmed working position.

[0053] After the status register update is completed, the status receipt frame assembly process begins. Following a preset frame structure, the opcode field from the current control command and the updated most recently confirmed status are filled into the corresponding fields of the status receipt frame. The preset frame structure specifies the order, bit width, and encoding format of each field in the receipt frame. The opcode field identifies the type of control command corresponding to this receipt, facilitating the control terminal's matching and association of the receipt with the original command. The confirmed status field carries the actual status information after the circuit breaker's action, allowing the control terminal to monitor and record the status. Furthermore, the receipt frame also includes the target circuit breaker's address encoding field and frame check field, ensuring the control terminal can correctly identify the receipt source and verify frame integrity. If the action is determined to be abnormal, an abnormal status flag is written into the status field of the receipt frame. Upon receiving this flag, the control terminal can trigger a frequency band switching and link reconstruction process.

[0054] After the assembled status feedback frame undergoes error correction coding, it is modulated with the carrier of the current operating frequency band and transmitted back to the control terminal via the power line. Upon receiving the feedback frame, the control terminal parses the operation code field and the confirmed status field within the frame, completing the closed-loop confirmation of this control process. The entire process, through the coordinated operation of the redundant operation judgment mechanism, the real-time acquisition mechanism of limit switches, and the status register overwrite update mechanism, achieves accurate status tracking and reliable feedback of the circuit breaker's operation process, effectively avoiding mechanical losses caused by repeated actions and providing accurate status feedback for the upper-level control logic.

[0055] In one optional implementation, when the status feedback frame indicates an abnormal action execution, the system determines whether the abnormality is a communication layer abnormality or a device layer abnormality based on whether the status information contains a mechanical fault identifier. If the abnormality is determined to be a communication layer abnormality, a hysteresis determination is performed on the current operating frequency band, removing frequency bands that meet the rejection criteria and reselecting an operating frequency band, including: Based on the status information carried in the status receipt frame, execution anomalies are classified according to the source of the fault. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information does not contain a mechanical fault identification code, it is determined to be a communication layer link anomaly. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information contains a mechanical fault identification code, it is determined to be a device layer execution anomaly. When a communication layer link is determined to be abnormal, a hysteresis determination is performed on the current working frequency band. If the proportion of sampling points with a signal-to-noise ratio below the preset removal threshold in the continuous sliding window exceeds the first preset proportion, it is determined that the removal condition is met. The current working frequency band that meets the removal condition is removed from the available frequency band set, and a frequency band is reselected from the remaining available frequency bands in the available frequency band set. The frequency band with the highest score is selected as the new current working frequency band.

[0056] like Figure 4 As shown, the method includes: This chart summarizes the execution results of various circuit breaker operation commands, covering key indicators such as successful opening, successful closing, redundancy suppression, and execution anomalies. There were 342 successful openings and 318 successful closings. Both operations require a complete command issuance, address comparison, CRC check, drive execution, and stroke completion confirmation process. The number of successes directly reflects the reliability of the control link and the accuracy of the actuator's response. Redundancy suppression occurred 92 times. This mechanism actively suppresses the drive signal and returns a confirmation frame when the status indicated by the operation code matches the locally confirmed status, avoiding additional wear on the mechanical structure from repeated actions. There were 8 execution anomalies. The system distinguishes the source of the anomaly based on the timeout duration and mechanical fault identification code in the receipt frame: for communication layer link anomalies, after triggering hysteresis judgment, the current degraded frequency band is removed, and a new optimal frequency band is selected and a configuration update frame is broadcast to rebuild the link; for equipment layer execution anomalies (including mechanical fault codes), the frequency band remains unchanged, and an equipment anomaly alarm frame is sent. The aforementioned multi-dimensional execution statistics provide a quantitative basis for system reliability assessment and fault diagnosis, and support the effectiveness verification of adaptive frequency band switching and link self-healing strategies.

[0057] After the status receipt frame is returned, the status information it carries needs to be parsed to distinguish whether the anomaly originates from the communication link layer or the device execution layer. During parsing, the timeout duration field in the status information is first read and compared with a preset timeout threshold. If the timeout duration exceeds the preset threshold, the status information is further checked to see if it contains a mechanical fault identification code. The mechanical fault identification code is a predefined specific sequence that the target circuit breaker actively writes into the status information field and sends back with the status receipt frame when it detects an internal mechanical structural anomaly (such as spring jamming, contact adhesion, or operating mechanism jamming). If the timeout duration exceeds the preset timeout threshold and the status information does not contain a mechanical fault identification code, the anomaly is determined to be a communication layer link anomaly, meaning the circuit breaker itself has the execution capability, but the command was not correctly received or the response was delayed due to carrier channel quality degradation. If the timeout duration exceeds the preset timeout threshold and the status information also contains a mechanical fault identification code, the anomaly is determined to be a device layer execution anomaly, meaning the circuit breaker's mechanical actuator has a physical fault, unrelated to communication link quality.

[0058] When a communication layer link anomaly is detected, the current operating frequency band cannot be directly removed from the available frequency band set. Instead, a hysteresis check must first be performed on the frequency band to avoid erroneous removal due to occasional interference. The core mechanism of the hysteresis check is sliding window sampling statistics: within a continuous time window, the signal-to-noise ratio (SNR) of the current operating frequency band is periodically sampled, the instantaneous SNR value obtained in each sample is recorded, and the number of sampling points below a preset removal threshold is counted. Let the total number of sampling points within the sliding window be... The number of sampling points with a signal-to-noise ratio lower than the preset rejection threshold is . The proportion of sampling points below the rejection threshold is... satisfy .when Exceeding the first preset ratio When the frequency band meets the exclusion criteria, it is determined that the frequency band is excluded; if Not exceeding If the interference is intermittent, the current operating frequency band will be retained, and the frequency band switching process will not be triggered. The purpose of introducing the hysteresis judgment mechanism is to improve the stability of frequency band management, prevent frequent frequency band switching caused by short-term channel fluctuations, and thus avoid the negative impact of repeated reconstruction of communication links on the overall system reliability.

[0059] When the exclusion criteria are met, the current operating frequency band is removed from the available frequency band set and will no longer be considered as a candidate in subsequent frequency band selection processes. Then, from the remaining available frequency bands in the available frequency band set, they are sorted according to their frequency band selection scores, and the frequency band with the highest score is selected as the new current operating frequency band. The frequency band selection score comprehensively reflects the channel quality of each frequency band; the frequency band with the highest score has the optimal current channel conditions, providing the greatest reliability guarantee for subsequent communication. After the selection of the new operating frequency band is completed, an update configuration frame is broadcast to all connected smart circuit breakers on the power line. The update configuration frame contains the new current operating frequency band index. Upon receiving the update configuration frame, each circuit breaker parses the frequency band index field, updates its locally stored operating frequency band parameters to the new frequency band, and re-establishes the carrier communication link on the new frequency band, completing the communication link reconstruction process. After reconstruction, the control terminal can resend control commands that failed to execute due to link anomalies on the new operating frequency band, ensuring that the circuit breaker action commands are responded to correctly.

[0060] When an anomaly is detected at the device layer, the processing logic differs significantly from that at the communication layer. Since the anomaly originates from the circuit breaker's mechanical actuator and is unrelated to the channel quality of the current operating frequency band, the current operating frequency band is maintained unchanged, and the ownership status of any frequency band in the available band set is not modified; that is, no band removal or switching operations are triggered. Based on this, a device anomaly alarm frame is sent to the control terminal via the carrier of the current operating frequency band. The frame structure of the device anomaly alarm frame contains two key fields: a target address field and a mechanical fault identification code. The target address field identifies the specific circuit breaker device experiencing the mechanical fault, enabling the control terminal to accurately locate the physical position of the faulty device. The mechanical fault identification code clearly indicates to the control terminal that the fault type is a physical fault at the mechanical actuator level, rather than a soft anomaly at the communication layer. Upon receiving the device anomaly alarm frame, the control terminal can query the installation location information of the corresponding circuit breaker based on the target address field and trigger the corresponding maintenance and handling procedures, such as issuing an on-site repair work order to maintenance personnel to arrange for physical inspection and maintenance or replacement of the mechanical components of the circuit breaker.

[0061] The design logic of the above-mentioned fault classification and differentiated handling mechanism lies in the fact that communication layer link anomalies and equipment layer execution anomalies are fundamentally different in terms of their causes, scope of impact, and handling methods. Communication layer link anomalies are channel environment problems, which can be resolved by switching the operating frequency band without any intervention in the circuit breaker hardware. Equipment layer execution anomalies, on the other hand, are physical hardware faults, and switching the frequency band cannot solve the problem. Forcing a frequency band switch will introduce unnecessary link reconstruction overhead and may cause a temporary interruption of communication for other normally operating circuit breakers. By introducing mechanical fault identification coding into the status feedback frame, the fault diagnosis capability is decentralized to the circuit breaker itself. This allows the control end to complete the accurate classification of the fault source without additional round-trip communication, significantly improving the response efficiency and accuracy of anomaly handling. It also avoids invalid frequency band switching operations caused by incorrect judgments, ensuring the stable operation of the entire power line carrier communication network.

[0062] A second aspect of the present invention provides an intelligent circuit breaker control system based on power line carrier communication, comprising: The initialization unit is used to periodically send carrier detection signals to the power line, obtain the channel attenuation and noise distribution of multiple preset frequency bands, determine the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands, obtain the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive detection periods, calculate the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, select the frequency band with the highest score as the current working frequency band, assign address codes to each smart circuit breaker and broadcast configuration frames; The modulation and transmission unit is used to generate data frames in response to control commands, perform first error correction encoding on the data frames with a first symbol length, concatenate the first and last data frames, and then perform second error correction encoding with a second symbol length. The first symbol length is less than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frames are then transmitted via carrier modulation. The comparison and verification unit is used to demodulate and decode the target circuit breaker to restore the data frame and perform address comparison and verification. The feedback unit reads the most recently confirmed status from the status register when the verification is successful. If the operation type indicated by the operation code field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and update the status register. The status information is then assembled into a status feedback frame and sent back. The frequency band selection unit, similar to the status feedback frame indicating an abnormal action execution, determines whether the status information contains a mechanical fault identifier as a communication layer abnormality or an equipment layer abnormality. If it is determined to be a communication layer abnormality, it performs a hysteresis judgment on the current working frequency band, removes the frequency bands that meet the rejection conditions, and reselects a working frequency band.

[0063] A third aspect of the present invention provides an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the aforementioned method.

[0064] A fourth aspect of the present invention provides a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the aforementioned method.

[0065] This invention can be a method, apparatus, system, and / or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of the invention.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart circuit breaker control method based on power line carrier communication, characterized in that, include: The system periodically sends carrier probe signals to the power line to obtain channel attenuation and noise distribution of multiple preset frequency bands. It identifies the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands. It obtains the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive probe cycles. It calculates the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, selects the frequency band with the highest score as the current working frequency band, assigns address codes to each smart circuit breaker, and broadcasts configuration frames. In response to control commands, a data frame is generated. The data frame is then concatenated after being encoded with a first symbol length and then encoded with a second symbol length. The first symbol length is shorter than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frame is then transmitted via carrier modulation. The target circuit breaker demodulates, decodes, and restores the data frame, and performs address comparison and verification. When the verification is successful, the most recently confirmed status is read from the status register. If the operation type indicated by the opcode field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and the status register is updated. The status information is then assembled into a status receipt frame and sent back. When the status feedback frame indicates an abnormal action execution, it is determined whether the status information contains a mechanical fault identifier or a communication layer abnormality. If it is determined to be a communication layer abnormality, a hysteresis judgment is performed on the current working frequency band, and the frequency band that meets the rejection conditions is removed and a new working frequency band is selected.

2. The method according to claim 1, characterized in that, Carrier probe signals are periodically sent to the power line to obtain channel attenuation and noise distribution in multiple preset frequency bands. Frequency bands with a signal-to-noise ratio (SNR) higher than a preset noise threshold are identified as the set of usable frequency bands. The linear fitting slope of the SNR for each usable frequency band over multiple consecutive probe periods is obtained. A frequency band selection score is calculated using a weighted average of the linear fitting slope and the current SNR, and the frequency band with the highest score is selected as the current working frequency band, including: After each carrier probe signal transmission and acquisition of channel attenuation and noise distribution, the ratio of the number of currently available frequency bands in the available frequency band set to the total capacity of the available frequency band set is calculated as the frequency band availability rate. The next probe signal transmission interval is determined based on the frequency band availability rate change trend of the most recent consecutive probe cycles. When the frequency band availability rate continues to decline and the decline exceeds the preset deterioration threshold, the transmission interval is shortened by the first step length to increase the detection frequency. When the frequency band availability rate remains stable and the signal-to-noise ratio fluctuation of each available frequency band is lower than the preset stability threshold, the transmission interval is extended by the second step length to reduce the detection frequency. When selecting the current working frequency band from the available frequency band set, the linear fitting slope of the signal-to-noise ratio (SNR) value of each available frequency band over the most recent consecutive detection periods is obtained as the SNR change slope. A positive selection bias is assigned to available frequency bands with a positive SNR change slope and the largest positive value, and a negative selection bias is assigned to available frequency bands with a negative SNR change slope. The frequency band selection score is calculated by weighting the available frequency band's SNR change slope with the currently measured SNR, and the available frequency band with the highest frequency band selection score is selected as the current working frequency band.

3. The method according to claim 1, characterized in that, Assign address codes to each smart circuit breaker and broadcast configuration frames, including: The address codes of each smart circuit breaker on the power line are organized in a segmented structure. The address code is composed of the communication area segment, the device identification segment, and the verification segment, which are concatenated first by first. The communication area segment is determined based on the relative physical location of the smart circuit breaker in the power line access topology. The device identification segment is the fixed-length device identification value obtained by hash mapping operation after the unique identifier burned into the smart circuit breaker at the factory. The verification segment is generated by the communication area segment and the device identification segment according to the preset coding rules after bitwise XOR operation and cyclic shift operation. Each time the current operating frequency band is updated and a configuration frame is broadcast via carrier signal, the index information of the current operating frequency band after the update and the timestamp of the update are written together into the configuration register stored locally by each smart circuit breaker. After receiving the carrier signal, each smart circuit breaker demodulates the carrier frequency obtained by demodulation and looks up the latest frequency band index recorded in the local configuration register. The latest frequency band index obtained by looking up the latest frequency band index is compared bit by bit with the frequency band index value carried by the frequency band identifier field in the data frame to complete the consistency verification. If the verification fails, the data frame is discarded and a frequency band synchronization failure flag is returned.

4. The method according to claim 1, characterized in that, Carrier modulation transmission includes: The data frame is divided into multiple first symbol groups with a preset first symbol length. The first coding algorithm is used to perform first error correction coding for narrowband continuous noise interference on each first symbol group. The check bit generated by the first error correction coding is used as the first check unit and appended to the tail of the corresponding first symbol group to form a first error correction code block. The first coding algorithm adopts low redundancy group error correction coding. All first error correction code blocks are concatenated end to end in the order of their generation to form a first coding stream. The first coding stream is then re-divided into multiple second code block groups with a preset second code length. Each second code block is then subjected to second error correction coding for burst impulse noise interference using a second coding algorithm. The check bit generated by the second error correction coding is appended to the end of the corresponding second code block as a second check unit to form a second error correction code block. The length of the first code block is shorter than the length of the second code block, and the error correction capability of the second coding algorithm is stronger than that of the first coding algorithm. All the second error correction code blocks are connected end to end to form the code stream to be modulated. The code stream to be modulated is then modulated by a single carrier at the carrier frequency corresponding to the current working frequency band and injected into the power line for transmission via a coupling circuit.

5. The method according to claim 1, characterized in that, Assemble the status information into a status receipt frame and send it back, including: Read the most recently confirmed status of the circuit breaker from the status register stored locally in the target circuit breaker, after the most recent confirmation to the control terminal via a status acknowledgment frame. If the operation type indicated by the operation code field is opening and the most recently confirmed status is opening, or the operation type indicated by the operation code field is closing and the most recently confirmed status is closing, then determine that the current control command is a redundant operation request, suppress the generation of drive signals for the actuator, and return a status acknowledgment frame containing a redundant operation confirmation flag to the control terminal through the current operating frequency band. If the operation type indicated by the operation code field is inconsistent with the most recently confirmed status, a drive pulse signal corresponding to the operation type is generated to drive the actuator to perform the corresponding opening or closing action. After the drive pulse signal is sent, the travel position signal of the actuator is collected by the limit switch to determine the actual status of the circuit breaker after the action. The actual status of the circuit breaker is written into the status register to overwrite and update the most recently confirmed status. The operation code field contained in this control command and the updated most recently confirmed status are filled into the status receipt frame according to the preset frame structure, and the assembled status receipt frame is sent to the control terminal using the carrier of the current operating frequency band.

6. The method according to claim 1, characterized in that, When a status feedback frame indicates an abnormal action execution, the system determines whether the abnormality is due to a communication layer or a device layer based on whether the status information contains a mechanical fault identifier. If it is determined to be a communication layer abnormality, a hysteresis check is performed on the current operating frequency band. Frequency bands that meet the rejection criteria are removed, and a new operating frequency band is selected, including: Based on the status information carried in the status receipt frame, execution anomalies are classified according to the source of the fault. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information does not contain a mechanical fault identification code, it is determined to be a communication layer link anomaly. When the status information indicates that the duration of the action execution timeout exceeds the preset timeout threshold and the status information contains a mechanical fault identification code, it is determined to be a device layer execution anomaly. When a communication layer link is determined to be abnormal, a hysteresis determination is performed on the current working frequency band. If the proportion of sampling points with a signal-to-noise ratio below the preset removal threshold in the continuous sliding window exceeds the first preset proportion, it is determined that the removal condition is met. The current working frequency band that meets the removal condition is removed from the available frequency band set, and a frequency band is reselected from the remaining available frequency bands in the available frequency band set. The frequency band with the highest score is selected as the new current working frequency band.

7. A smart circuit breaker control system based on power line carrier communication, used to implement the method as described in any one of claims 1-6, characterized in that, include: The initialization unit is used to periodically send carrier detection signals to the power line, obtain the channel attenuation and noise distribution of multiple preset frequency bands, determine the frequency bands with a signal-to-noise ratio higher than a preset noise threshold as the set of available frequency bands, obtain the linear fitting slope of the signal-to-noise ratio of each available frequency band in multiple consecutive detection periods, calculate the frequency band selection score by weighting the linear fitting slope and the current signal-to-noise ratio, select the frequency band with the highest score as the current working frequency band, assign address codes to each smart circuit breaker and broadcast configuration frames; The modulation and transmission unit is used to generate data frames in response to control commands, perform first error correction encoding on the data frames with a first symbol length, concatenate the first and last data frames, and then perform second error correction encoding with a second symbol length. The first symbol length is less than the second symbol length and the error correction capability of the second encoding algorithm is stronger than that of the first encoding algorithm. The data frames are then transmitted via carrier modulation. The comparison and verification unit is used to demodulate and decode the target circuit breaker to restore the data frame and perform address comparison and verification. The feedback unit reads the most recently confirmed status from the status register when the verification is successful. If the operation type indicated by the operation code field is consistent with the most recently confirmed status, the drive signal is suppressed. If they are inconsistent, the actuator is driven to perform the action and update the status register. The status information is then assembled into a status feedback frame and sent back. The frequency band selection unit, similar to the status feedback frame indicating an abnormal action execution, determines whether the status information contains a mechanical fault identifier as a communication layer abnormality or an equipment layer abnormality. If it is determined to be a communication layer abnormality, it performs a hysteresis judgment on the current working frequency band, removes the frequency bands that meet the rejection conditions, and reselects a working frequency band.

8. An electronic device, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method described in any one of claims 1 to 6.

Images