A Control Method for Molded Case Circuit Breakers Based on HPLC Power Line Communication

Abstract

This invention relates to the field of intelligent control of circuit protection devices, specifically disclosing a control method for molded case circuit breakers based on HPLC power line communication. This method is executed by a controller integrated with an HPLC carrier module, and includes: actively sensing and acquiring the phase line position and real-time channel status parameters of the local node in a three-phase power distribution network; dynamically determining the optimal communication path for executing remote control commands based on this; performing signal conversion according to the path, and generating a drive signal after coordinating the command with local real-time protection parameters for safety assessment; and triggering adaptive optimization of node parameters or reporting data to the network to drive network-level resource reconfiguration based on the performance evaluation results of the communication process. This invention effectively solves the risk of command mis-execution and cross-phase communication bottlenecks caused by dynamic channel degradation through deep integration and closed-loop optimization of communication-sensing-protection-decision, achieving a comprehensive improvement in control safety, reliability, and system self-optimization capabilities.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for circuit protection devices, specifically to a control method for molded case circuit breakers based on HPLC power line communication. Background Technology

[0002] Molded case circuit breakers (MCCBs) are key components in low-voltage power distribution systems for circuit protection and on / off control. Traditional MCCBs primarily rely on local thermomagnetic tripping mechanisms or electronic tripping units to achieve protection functions. Their control depends on local manual operation or simple auxiliary contact signals, and they do not possess power line carrier communication capabilities, thus failing to achieve remote intelligent monitoring and control.

[0003] With the development of smart power distribution networks and IoT technology, existing technologies mainly employ two methods to endow molded case circuit breakers with remote communication capabilities: one is to add an independent communication unit external to the circuit breaker, and the other is to connect the communication module as an external component to the circuit breaker controller. In these solutions, the high-speed power line carrier communication (HPLC) module typically exists as an independent, external data channel, with low coupling to the control logic of the circuit breaker itself, undertaking only simple command feedback or status upload tasks. This architecture leads to three inherent technical bottlenecks:

[0004] First, the communication and protection functions are disconnected, creating a safety blind spot. The external HPLC module is only responsible for transmitting remote commands, and the circuit breaker controller usually executes them directly upon receiving them. This process is completely independent of, and may override, the local real-time current and voltage protection logic. When there are already potential faults such as overcurrent or short circuits in the line, the remote closing command may still be executed dangerously, causing a serious safety accident.

[0005] Second, the lack of awareness and adaptability to channel conditions results in poor communication reliability. Existing solutions treat the HPLC channel as an ideal or static channel with only on / off states. However, as a communication medium, the noise and impedance of power lines change drastically with load switching. When the channel deteriorates instantaneously, commands are prone to errors, such as mistaking a tripping switch for a closing switch. External modules cannot effectively transmit real-time channel quality parameters to the controller, thus the controller cannot make intelligent decisions and can only passively bear the risks of communication failures or malfunctions.

[0006] Third, it is difficult to support network-level coordination and optimization. For the inherent cross-phase communication bottleneck in three-phase distribution networks, external communication modules lack the ability to perceive the network topology, cannot determine their own phase, and cannot intelligently select the optimal relay path. Each circuit breaker node is isolated, unable to perform resource coordination and learning optimization, resulting in low overall network communication efficiency.

[0007] Therefore, existing solutions that treat HPLC modules as external accessories have fundamental flaws in terms of safety, reliability, and intelligence. There is an urgent need for a solution that deeply integrates HPLC communication capabilities into the circuit breaker controller, achieving a unified solution for communication, sensing, protection, and control. Summary of the Invention

[0008] The purpose of this invention is to provide a control method for molded case circuit breakers based on HPLC power line communication, so as to solve the fundamental problems in the prior art where the remote control and local protection functions of molded case circuit breakers are separated due to the external HPLC communication module, and the inability to safely and reliably execute remote control commands when communication is unreliable on dynamically degraded power line channels.

[0009] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0010] A control method for a molded case circuit breaker based on HPLC power line communication, wherein the controller of the molded case circuit breaker integrates an HPLC carrier module, and the method includes the following steps:

[0011] S1. Actively sense and acquire the phase line position and real-time channel status parameters of the molded case circuit breaker through the HPLC carrier module;

[0012] S2. Based on the phase line position and real-time channel state parameters, dynamically determine the optimal communication path for executing remote control commands;

[0013] S3. Perform signal conversion based on the optimal communication path, and coordinate the converted instruction with the local protection logic to generate and execute the drive signal;

[0014] S4. Based on the execution results of the optimal communication path and the channel state change data, evaluate the communication performance and trigger node parameter optimization or network resource reconfiguration.

[0015] As a preferred embodiment of the present invention, S1 specifically includes:

[0016] S11. When the molded case circuit breaker is powered on or reaches a preset cycle, the controller drives its integrated HPLC carrier module to broadcast a specific topology detection signal to the three-phase four-wire line of the low-voltage distribution network.

[0017] S12. The controller listens for and receives response signals from the network coordinator or other adjacent molded case circuit breakers to the topology probe signal;

[0018] S13. By analyzing the phase information contained in the response signal and combining it with the local three-phase voltage phase difference detected by the HPLC carrier module, the specific phase line position of this node is calculated and determined.

[0019] S14. During the interaction of the topology detection and response signals, the real-time channel state parameters of the current intra-phase communication and cross-phase link are read and obtained synchronously from the physical layer and link layer of the HPLC carrier module. The parameters include at least bit error rate, signal-to-noise ratio and signal strength.

[0020] As a preferred embodiment of the present invention, S13 specifically includes:

[0021] S131. From the response signal, parse out the identifier of the source node that sent the response signal and its phase information, or parse out the phase sequence information of each node in the routing path through which the response signal travels from the network coordinator to this node;

[0022] S132. By integrating the zero-crossing detection function of the HPLC carrier module into the controller, the phase angle of the local three-phase voltage relative to the neutral line is synchronously detected and obtained, and the voltage phase difference between each pair is calculated.

[0023] S133. Match and logically deduce the phase information with the local voltage phase relationship. If the response signal clearly indicates that the source node is a specific phase, then combine the signal strength and the local phase difference to confirm whether the current node is in the same phase as the source node. If the response signal contains a routing path phase sequence, then infer the specific phase line connected to the current node in the three-phase topology based on the phase relationship of adjacent nodes in the sequence and the local voltage phase difference.

[0024] As a preferred embodiment of the present invention, S2 specifically includes:

[0025] S21. Determine whether the source node and local node of the remote control command are on the same phase line; if so, pre-select the direct in-phase communication path as a candidate path; otherwise, proceed to the cross-phase path decision process.

[0026] S22. In the cross-phase path decision process, if it is determined that there is a bottleneck in cross-phase communication, then the relay path decision is initiated.

[0027] S23. Based on the real-time channel state parameters, select at least one node with the optimal channel state from other known nodes located on different phase lines as an out-of-phase intermediate node, and determine an optimal communication path for signal relay forwarding through the out-of-phase intermediate node; the relay forwarding method is power line carrier relay.

[0028] As a preferred embodiment of the present invention, S22 specifically includes:

[0029] S221. Compare the cross-signal-to-noise ratio in the real-time channel state parameters with a dynamic first preset threshold, and compare the cross-phase bit error rate with a dynamic second preset threshold; if the cross-signal-to-noise ratio is continuously lower than the first preset threshold for a first preset duration, or the cross-phase bit error rate is continuously higher than the second preset threshold for a second preset duration, then generate a bottleneck confirmation signal;

[0030] S222. Simultaneously with the generation of the bottleneck confirmation signal, the relay path decision algorithm is activated by combining the phase line position information of the local node and adjacent nodes. The algorithm takes the real-time channel state parameters and phase line position information as input and begins to select the optimal relay node and calculate the path.

[0031] As a preferred embodiment of the present invention, S23 specifically includes:

[0032] S231. Based on the phase line position of the molded case circuit breaker and the known network topology information, all adjacent nodes that are on different phase lines from the local node and are recorded as valid relay candidates are selected to form an initial relay candidate node set.

[0033] S232. For each candidate node in the initial relay candidate node set, extract real-time channel state parameters and calculate a comprehensive channel evaluation value; the calculation is based at least on the signal-to-noise ratio from the candidate node to the local node, the estimated signal-to-noise ratio from the candidate node to the remote command source node or the previous hop relay node, and the historical relay success rate of the candidate node.

[0034] S233. Compare the comprehensive channel evaluation values ​​of all candidate nodes, determine one or more candidate nodes with the highest comprehensive channel evaluation values ​​as the nodes with the optimal channel state, and use them as out-of-phase intermediate nodes to generate one or more relay forwarding paths that explicitly include the source node, relay node and target node, and decide the path with the highest comprehensive evaluation as the optimal communication path.

[0035] As a preferred embodiment of the present invention, S3 specifically includes:

[0036] S31. The controller calls the HPLC carrier module to monitor and receive signals according to the optimal communication path;

[0037] S32. The controller demodulates, decodes, and converts the received signals to extract the effective data payload carrying remote control commands or relay forwarding commands;

[0038] S33. The parsed instruction content is logically coordinated with the line current and voltage protection parameters monitored locally by the controller in real time to generate a corresponding local drive instruction;

[0039] S34. The local drive command is converted into a drive signal with specific timing and power, and output to the tripping mechanism or electric operating mechanism of the molded case circuit breaker to perform the corresponding operation.

[0040] As a preferred embodiment of the present invention, S33 specifically includes:

[0041] S331. Decode and verify the format of the instruction content to confirm whether it is a valid remote tripping or closing command that conforms to a predefined protocol; if not, terminate the process and discard the instruction content.

[0042] S332. While verifying the validity of the instruction content, the line current value and voltage value collected by the current sensor and voltage sensor built into the controller are acquired in real time. The line current value is compared with the preset overcurrent trip threshold, and the voltage value is compared with the preset undervoltage or overvoltage trip threshold.

[0043] S333. The decision is to allow execution only if the instruction content is confirmed to be a valid opening and closing command, and the comparison result confirms that all line current values ​​and voltage values ​​have not reached their respective protection tripping thresholds;

[0044] S334. If and only if the security logic decision result is that execution is allowed, the controller generates a corresponding local drive instruction for driving the opening or closing operation according to the specific type of the instruction content; if the security logic decision result is that execution is prohibited, the controller does not generate a drive instruction and may choose to report an alarm message with local protection priority.

[0045] As a preferred embodiment of the present invention, S4 specifically includes:

[0046] S41. The controller calculates the key performance indicators of this communication based on the actual execution results of the optimal communication path. The performance indicators include at least the instruction transmission success rate and the end-to-end transmission delay. At the same time, it compares the channel state change data obtained before and after the communication.

[0047] S42. If the evaluation confirms that the communication successfully uses this node as a relay node, the controller adaptively optimizes at least one communication parameter of this node based on key performance indicators and channel state change data. The communication parameters include carrier transmit power, relay forwarding priority or channel access eavesdropping duration, and the optimized parameters are applied to subsequent relay tasks.

[0048] S43. If the assessment confirms that the communication failed due to a channel bottleneck, the controller generates a network optimization suggestion message. The message encapsulates the phase line position of this node, the associated real-time channel state parameters, the communication failure type, and the optimal communication path information. The controller reports the network optimization suggestion message to the network coordinator through the HPLC carrier module at a preset periodic reporting time or when the channel is detected to be idle, so that the coordinator can perform network-level routing table updates or relay resource reconfiguration.

[0049] As a preferred embodiment of the present invention, S41 specifically includes:

[0050] S411. The controller records key event timestamps for this communication transaction corresponding to the optimal communication path. The timestamps include at least the start time of receiving the remote control command, the time of generating the drive signal, and the final application layer confirmation time for the command received from the network. Based on the timestamps, the end-to-end transmission delay is calculated. At the same time, the command transmission success rate is calculated based on the correctness and integrity of the data packets received during this communication process and whether the final application layer confirmation is received.

[0051] S412. The controller retrieves an initial channel state parameter snapshot related to the optimal communication path at the instant before the start of the current communication transaction, and a latest channel state parameter snapshot at the instant after the completion of the communication transaction; compares the initial and latest channel state parameter snapshots, and calculates the change in key channel parameters, wherein the change includes at least the change in path signal-to-noise ratio and the change in path bit error rate;

[0052] S413. The controller associates and stores the command transmission success rate and end-to-end transmission delay with the changes in key channel parameters, forming a complete performance evaluation record that includes path identifiers, performance indicators and channel changes.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] 1. Through proactive network topology sensing and intelligent relay path decision-making, the system can automatically switch to the optimal relay path when traditional cross-phase communication deteriorates, fundamentally ensuring the reliable transmission of remote control commands in a complex three-phase power grid.

[0055] 2. By forcibly coordinating remote commands with local real-time protection parameters, it is ensured that the execution of any control command is based on the premise that the line is currently fault-free, thus eliminating the risk of malfunction in protection blind spots.

[0056] 3. Through performance evaluation of a single communication transaction and network-level feedback, nodes can adaptively optimize and provide precise optimization basis to the network coordinator, thereby achieving continuous self-improvement of the communication resilience and efficiency of the entire system. Attached Figure Description

[0057] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0058] Figure 1 This is a schematic diagram summarizing the process of the method described in Embodiment 1 of the present invention.

[0059] Figure 2 This is a schematic diagram illustrating the specific process of the method described in Embodiment 1 of the present invention. Detailed Implementation

[0060] 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.

[0061] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0062] Example 1

[0063] like Figure 1 - Figure 2 As shown, this invention provides a control method for molded case circuit breakers based on HPLC power line communication. The controller of the molded case circuit breaker integrates an HPLC carrier module, and the method includes the following steps:

[0064] S1. Actively sense and acquire the phase position and real-time channel status parameters of the molded case circuit breaker through the HPLC carrier module; specifically including:

[0065] S11. When the molded case circuit breaker is energized or reaches a preset cycle, the controller drives its integrated HPLC carrier module to broadcast a specific topology detection signal to the three-phase four-wire line of the low-voltage distribution network; specifically:

[0066] S111. When the molded case circuit breaker completes the power-on initialization process or the internal timer reaches the preset period threshold, the controller sends a start command to the integrated HPLC carrier module through the GPIO interface or dedicated bus.

[0067] After receiving the command, the S112.HPLC carrier module constructs a topology probe message according to the G3-PLC or IEEE 1901.1 standard. The message contains at least the following data fields: the unique MAC address of this node, the device type identifier, the protocol version number, the probe serial number, and the hash value used for security verification.

[0068] The S113.HPLC carrier module performs OFDM modulation on the message data and sets the target address as the broadcast address. It then couples the data to the three-phase four-wire line of the low-voltage distribution network via a power amplifier circuit. To ensure full three-phase coverage, the carrier module sequentially transmits probe signals on three independent physical channels—A, B, and C phases and the neutral line—using a time-division or parallel method. The transmission time for each channel must avoid the power frequency zero-crossing region to reduce attenuation. The transmission power is configured according to the carrier module's preset initial transmission level, typically within the range of -55 dBm / Hz to -45 dBm / Hz. The transmission duration is controlled between 50 milliseconds and 200 milliseconds to avoid prolonged channel occupancy.

[0069] S12. The controller listens for and receives response signals from the network coordinator or other adjacent molded case circuit breakers to topology probe signals; specifically:

[0070] S121. After the topology detection signal is emitted, the controller immediately switches the HPLC carrier module to the receiving monitoring mode, and continues to listen for no less than 500 milliseconds or until a valid response is received. During the listening period, the receiving front-end circuit of the carrier module samples the carrier signal on the three-phase four-wire line in real time, filters out the 50Hz power frequency and its harmonic interference through a bandpass filter, and then performs automatic gain control and analog-to-digital conversion.

[0071] S122. When the physical layer detects a signal that matches the protocol frame header characteristics, it initiates the frame synchronization and decoding process. The decoded message is submitted to the link layer for address matching and validity verification, including whether the destination address is the local node's or broadcast address, whether the protocol version is compatible, whether the checksum is correct, and whether the probe sequence number is consistent with the sequence number sent in S11.

[0072] S123. A valid response signal is considered effective, and its source node type may be the network coordinator or other molded case circuit breaker nodes with relay function in the same transformer area. If no valid response is received after the preset timeout period, the controller will record the event log and may trigger a retry mechanism or switch to the standby trigger condition.

[0073] S13. Accurate determination of phase line position is achieved through joint analysis of response signal parsing and local electrical measurements. This process is uniformly scheduled by the phase recognition state machine in the controller firmware, sequentially executing three progressive stages: information extraction, measurement acquisition, and logic fusion; specifically:

[0074] S131. The message parsing module in the controller firmware first locates the valid response frame that has passed CRC check in the link layer receive buffer, and extracts the source MAC address field from the fixed offset position of the frame header. This field occupies 6 bytes and is used to uniquely identify the device identity of the network coordinator or adjacent molded case circuit breaker node.

[0075] Phase information parsing requires differentiated processing based on message type: If the responding node is a terminal device, the phase encoding subfield located at offset 0x02 in the application layer payload is directly extracted. This field is a 2-bit compact encoding, following the mapping rule that 00 represents phase A, 01 represents phase B, and 10 represents phase C. If the source node is a network coordinator, its message usually carries an extended phase state bitmap. The controller needs to prioritize parsing the phase line channel marked as effectively coupled and with the best received signal strength in this bitmap as the reference phase.

[0076] When the response signal involves cross-phase relay transmission, the path tracing option in the message header will be activated. The controller needs to parse the relay node sequence contained in this option hop by hop. Each hop record consists of a 2-byte short address of the node and a 2-bit phase line code. This allows for the complete reconstruction of the phase line transition sequence experienced on the transmission path from the network coordinator to this node, such as the complete transfer trajectory of phase A → phase B → phase C. This sequence information provides key input for subsequent out-of-phase inference.

[0077] During the parsing process, the received signal strength indication value automatically recorded by the physical layer is extracted synchronously. The controller reads the carrier module register through the SPI interface to obtain the quantization value, which has a resolution of 0.5dB and a dynamic range covering -120dBm to -30dBm. This value will be used for subsequent signal reliability assessment.

[0078] S132. Accurate acquisition of local three-phase voltage phase difference:

[0079] The controller utilizes the zero-crossing detection unit built into the HPLC carrier module. This unit integrates three independent high-resistance voltage divider networks, each consisting of three precision metal film resistors. The total resistance is typically set to 900 kΩ to 1.2 MΩ, and the voltage divider ratio is designed to be 200:1 to 300:1, ensuring that the 220V phase voltage is attenuated to approximately 1V within the range of the A / D converter.

[0080] The analog voltage signal after voltage division is input to the three-channel synchronous sampling ADC built into the carrier chip. The ADC resolution is no less than 12 bits, and the sampling rate is configured to 12.8kHz, which is 256 times the power frequency of 50Hz, enabling dense acquisition of 256 sampling points per cycle.

[0081] The zero-crossing detection algorithm runs in interrupt mode in the DSP core of the carrier module. Its mathematical essence is linear interpolation: when the sampled value crosses the zero point, the algorithm uses the values ​​and time of the two adjacent sampled points to perform linear interpolation to accurately calculate the real zero-crossing time. The time resolution can reach 0.5 microseconds, corresponding to a phase angle resolution of 0.009 degrees.

[0082] The controller reads the latest zero-crossing timestamps of phases A, B, and C from the carrier module every 20 milliseconds, and denoted as t. A t B t C Based on the theoretical benchmark of power frequency period T=20 milliseconds, the pairwise phase difference is calculated: AB phase difference ΔΦ AB =[(t B -t A ) / T]×360°, BC phase difference ΔΦ BC =[(t C -t B ) / T]×360°, AC phase difference ΔΦ CA =[(t A -t C The result is calculated as 360° () / T], and the results of 16 consecutive cycles are filtered by moving average to suppress random noise, finally obtaining a stable three-phase voltage phase difference measurement vector.

[0083] S133. The controller fuses the source node phase information obtained in S131 with the local phase relationship measured in S132 to perform two-branch logic reasoning:

[0084] If the response signal clearly indicates that the source node is a single specific phase, for example, if the source node phase code is parsed as 00 and the signal strength RSSI is greater than -75dBm, then the in-phase confirmation process is initiated: the controller checks the locally measured AB phase difference ΔΦ. AB Does it fall within the tolerance range of [110°, 130°] and has a phase difference ΔΦ between AC and AC? CAWithin the range of [230°, 250°], verify that the local phase sequence conforms to the characteristics of phase A; then calculate the time deviation Δt between the arrival time of the response signal and the zero-crossing time of the local phase A voltage. If Δt is less than ±0.5 milliseconds, it is determined that the local node and the source node belong to phase A; if Δt is between ±0.5 and ±1.5 milliseconds, it is marked as a suspected phase A, and needs to be continuously verified in the subsequent three detection cycles to accumulate confidence.

[0085] If the response signal contains a phase sequence of the routing path, for example, if path tracing data shows the transmission path as coordinator phase A → node XB phase → this node, then the controller can determine through sequence analysis that this node must be phase B or C. In this case, the signal strength determination is skipped, and the controller directly uses the locally measured phase difference ΔΦ between phases B and C. BC Phase difference ΔΦ with BA AB The measured values ​​are matched for consistency. If the phase difference between BC and ΔΦ is... BC Approximately 120° and BA phase difference ΔΦ AB If the angle approaches 240°, then this node is finally confirmed to belong to phase B.

[0086] A timestamp alignment mechanism is introduced during the determination process. If the source node message carries GPS synchronization time or IEEE 1588 precision clock information, the controller can calculate the absolute delay of signal propagation and estimate the transmission distance by combining the propagation speed of power lines. When the distance is less than 50 meters and the phase matches, the determination confidence level is increased to more than 95%.

[0087] The final identification result is written to the node configuration area of ​​the controller's EEPROM or Flash memory in 2-bit encoded form, and a 3-bit confidence flag is set. The identification result must be consistent in at least two out of three consecutive detections to be finally solidified; otherwise, the result of the previous cycle is maintained and a low confidence alarm is triggered. At the same time, a query API interface is provided to the upper-layer application for the path decision module to call.

[0088] S14. During the duration of the topology detection and response interaction, the controller extracts channel quality parameters in real time through the physical layer management entity and the link layer management entity of the HPLC carrier module.

[0089] The parameters provided by the physical layer include: Received Signal Strength Indicator (RSSI), which reflects the signal amplitude and is measured in dBm; Signal-to-Noise Ratio (SNR), which is obtained by estimating the ratio of the received signal power to the background noise power spectral density and is measured in dB; and Bit Error Rate (BER), which is calculated by statistically analyzing the ratio of the number of hard decision bit errors before decoding to the total number of bits, typically using a sliding window statistical method.

[0090] The parameters provided by the link layer include: Frame Error Rate (FER), which is the ratio of the number of received erroneous frames to the total number of frames; Channel Occupancy Rate, which measures the proportion of busy time in the Carrier Sense Multiple Access (CSMA / CA) collision avoidance mechanism; and Retransmission Count, which records the average number of attempts to successfully transmit a single frame.

[0091] The controller independently counts and stores the parameters of communication within the current phase line (i.e., communication between this node and other nodes in the same phase) and cross-phase link communication (i.e., communication between this node and nodes in different phases through capacitive coupling or cross-phase relay), forming a channel state parameter vector to provide a quantitative basis for path decision-making in the subsequent step S2.

[0092] S2. Based on the phase line position and real-time channel state parameters, dynamically determine the optimal communication path for executing remote control commands; specifically including:

[0093] S21. Determine whether the source node and local node of the remote control command are on the same phase line:

[0094] The path decision engine in the S211 controller firmware first extracts the source node's MAC address from the received remote control command frame header. It then queries the locally maintained network topology cache table to obtain the phase line position code that the source node has identified and stored in the S1 phase or historical interactions. The topology cache table is implemented using a hash table structure, with the node's MAC address as the key and a structure containing the phase line code, last update timestamp, and confidence level as the value.

[0095] S212. If the query is successful and the confidence level is higher than the confidence threshold, the phase line code of the source node is read directly; if the query is unsuccessful or the confidence level is insufficient, the controller triggers the immediate topology supplementation mechanism, sends a unicast topology query message to the source node, and waits for a response to complete the phase line identification.

[0096] S213. After obtaining the source node phase line code, the controller reads the local node phase line code stored in local storage from step S13 and performs a bit-by-bit comparison between the two:

[0097] If the codes are exactly the same, it is determined to be a co-phase communication scenario. The controller immediately marks the direct co-phase communication path as a candidate path and starts the parallel evaluation process of S23 to verify the quality of the co-phase path.

[0098] If the encoding is different, it is determined to be a cross-phase communication scenario. The controller disables the direct communication path option and activates the cross-phase bottleneck analysis mechanism of S22.

[0099] In the in-phase determination branch, the controller synchronously records the timestamp of the determination result and sets a validity period of 15 minutes. During this period, there is no need to repeat the complete identification process of S13. It is only necessary to verify that no abnormal switching of the phase line has occurred through rapid zero-crossing detection.

[0100] S22. In the cross-phase path decision-making process, if a bottleneck is determined to exist in cross-phase communication, then the relay path decision is initiated; specifically:

[0101] S221. Dynamic threshold comparison and continuous monitoring:

[0102] The controller extracts cross-phase specific metrics from the real-time channel state parameter vector collected by S14, including cross-phase signal-to-noise ratio (SNR) and cross-phase bit error rate (BER). Cross-phase SNR is defined as the average SNR reported by the physical layer when the local node communicates with the out-of-phase node, while BER is the bit error rate when sending test frames or historical data frames to the out-of-phase node.

[0103] The controller firmware maintains two dynamic threshold variables: a first preset threshold and a second preset threshold, with initial values ​​configured as 10dB and 1×10, respectively. -3 However, it can be remotely adjusted through configuration messages issued by the network coordinator, or dynamically corrected based on adaptive learning of the historical communication statistics of this node.

[0104] The specific continuous monitoring logic is as follows: the controller collects cross-signal-to-noise ratio (SNR) and bit error rate (BER) every 100 milliseconds and stores them in a circular buffer of length 30, forming a 3-second sliding time window. If the K most recent sample values ​​in the circular buffer are consistently lower than the first preset threshold, and the K value reaches the number of samples corresponding to the first preset duration (usually configured as 2 seconds), then a signal-to-noise ratio bottleneck confirmation signal is generated. Similarly, if the M most recent samples in the BER buffer are consistently higher than the second preset threshold, and the M value reaches the number of samples corresponding to the second preset duration (usually set as 1.5 seconds), then a BER bottleneck confirmation signal is generated.

[0105] The two sub-signals are logically ORed to generate the final bottleneck confirmation signal, which triggers the activation of the relay path decision algorithm in S222. If the bottleneck determination condition is not met, the controller still retains the direct cross-phase communication path as a candidate, but marks it as a restricted path and enables the forward error correction coding rate adaptive boost and transmit power compensation mechanism to attempt to improve communication quality.

[0106] S222. Upon receiving the bottleneck confirmation signal, the relay path decision algorithm is immediately initiated. When the algorithm is activated, the controller first locks a snapshot of the current network topology. This snapshot contains the phase line position information and real-time channel state parameters of the current node, the source node, and one-hop adjacent nodes. The algorithm takes the channel state parameter matrix and phase line position vector as input. Rows in the matrix represent the current node, columns represent candidate relay nodes, and element values ​​are the signal-to-noise ratio, bit error rate, and signal strength of the corresponding link. The core objective of the algorithm is to maximize the end-to-end communication success rate while satisfying the out-of-phase relay constraint. After activation, the algorithm sends a relay discovery request to the network layer, triggering neighboring nodes to broadcast their availability and channel quality. This process is implemented through an optimized flooding mechanism, ensuring that candidate node information collection is completed within 500 milliseconds.

[0107] S23. Based on the real-time channel state parameters, select at least one node with the optimal channel state from other known nodes located on different phase lines as an out-of-phase intermediate node, and determine an optimal communication path for signal relay forwarding through the out-of-phase intermediate node; the relay forwarding method is power line carrier relay; specifically:

[0108] S231. Perform initial selection of the candidate relay node set:

[0109] Based on the phase line position code of the local node determined in S13, the controller traverses all adjacent node entries stored in the local network topology cache table. The filtering conditions are as follows: the XOR result of the phase line code of the adjacent node and the phase line code of the local node is not zero, that is, the two are on different phase lines; the relay enable flag bit of the adjacent node in the topology table is true. This flag bit is set by the node capability declaration message or the network coordinator configuration, indicating that the node has signal regeneration and forwarding capabilities; the difference between the last online timestamp of the adjacent node and the current time is less than 5 minutes, ensuring that the node is in an active state; the adjacent node is not in a relay overload state, that is, the number of concurrent relay connections does not exceed the preset limit, which is usually 3 to 5.

[0110] Neighboring nodes that meet the above four conditions are added to the initial relay candidate node set, which is dynamically maintained in a linked list structure. Each node element contains its MAC address, phase line code, real-time channel parameter pointer, and historical relay statistics field.

[0111] S232. Perform comprehensive channel evaluation value calculation for each node in the candidate node set:

[0112] The evaluation function employs a weighted summation model, with weight coefficients obtained through offline training or online reinforcement learning optimization. The input must contain at least three dimensions: the signal-to-noise ratio (SNR) from the candidate node to the local node. local This value is read directly from the channel state parameters collected by S14; the estimated signal-to-noise ratio (SNR) from the candidate node to the remote command source node or the previous hop relay node.remote If a candidate node has a history of direct communication with the source node, historical statistics are read; otherwise, estimated values ​​based on distance attenuation and cross-phase coupling loss models are used. Distance is inferred from received signal strength, and cross-phase coupling loss is compensated based on a typical distribution network topology of 15dB to 25dB. Historical relay success rate R... success This value is stored in the corresponding entry in the topology table. It is calculated as the ratio of the number of successful deliveries in the last 100 relay forwarding operations to the total number of attempts. The initial value is 0.8 by default.

[0113] The formula for calculating the comprehensive channel evaluation value is: Score = w1 × SNR local + w2×SNR remote + w3×(R success (×100), where w1, w2, and w3 are normalized weights, typically configured as w1=0.4, w2=0.4, and w3=0.2, emphasizing end-to-end link quality balance. For multi-relay path scenarios, the evaluation value is expanded to the harmonic mean or minimum value of the scores of each hop on the path, ensuring optimal end-to-end bottleneck link quality.

[0114] S233. Execute the final path decision:

[0115] The controller sorts the Score values ​​of all nodes in the candidate node set in descending order. If a single relay path strategy is adopted, the node with the highest Score value is selected as the out-of-phase intermediate node, and a path entry with a length of three hops is generated: source node → relay node → this node, and this path is marked as the optimal path.

[0116] If the multi-path redundancy strategy is enabled, the two nodes with the highest Score values ​​are selected to generate independent relay paths. The two paths will be concurrently or switched over to the primary or backup path in the S3 phase according to the urgency of the instructions.

[0117] During path generation, the controller synchronously calculates the estimated end-to-end delay of the path, including the transmission waiting delay for each hop, the carrier modulation and demodulation delay, and the relay processing delay. If the total delay exceeds the timeliness requirement of the remote control command, the priority of the path will be downgraded even if the channel quality is optimal.

[0118] The final decision result is stored in the form of a path descriptor structure, which includes path ID, path type enumeration value, relay node address list, path score value and validity period timestamp. This descriptor is submitted to the instruction forwarding and execution module of step S3 to drive the subsequent signal conversion and collaborative judgment process.

[0119] After the decision is made, the controller initiates the path quality tracking mechanism, which collects actual communication performance data in the S4 stage. This data is then used to update the weight coefficients and predicted parameters in the channel evaluation model, thereby achieving closed-loop optimization of the decision algorithm.

[0120] S3. Perform signal conversion based on the optimal communication path, and coordinate the converted instructions with local protection logic to generate and execute drive signals; specifically including:

[0121] S31. The communication scheduling module in the controller firmware first reads the optimal communication path descriptor structure generated in S23 and extracts the path type enumeration value.

[0122] If the path type is direct in-phase communication, the controller writes the unicast listening configuration to the HPLC carrier module through the SPI interface, sets the receive filter register to only allow the source node MAC address to pass through, and enables the receive signal strength threshold triggering mechanism to avoid low-quality signal interference.

[0123] If the path type is a relay path, the controller configures the carrier module to enter multi-source monitoring mode, sets the receive filter to allow both the source node MAC address and the relay node MAC address to pass through simultaneously, and activates the path tracing option parsing function to identify whether the packet is transmitted along the expected relay link.

[0124] After the monitoring mode is configured, the controller starts a receive timeout timer. The timeout duration is dynamically set based on the estimated path delay, typically between 300 and 800 milliseconds. During the monitoring period, the physical layer of the carrier module continuously listens for the carrier on the three-phase four-wire line, performing preamble detection and frame synchronization. Once a valid signal that meets the filtering conditions is captured, it immediately notifies the controller via a hardware interrupt and stores the original modulated signal sample in the receive FIFO buffer.

[0125] S32. The demodulation, decoding, and protocol conversion processes unfold layer by layer in the controller application layer protocol stack:

[0126] After the controller reads the raw signal sample from the receiving FIFO, it first submits it to the demodulation engine of the HPLC carrier module. The demodulation engine performs inverse OFDM demodulation according to the modulation parameters configured in S31, including FFT transformation, channel estimation and equalization, constellation diagram mapping and descrambling operation, and outputs bit stream data.

[0127] The bit stream is decoded by the forward error correction decoder built into the carrier module using Viterbi or LDPC to correct errors introduced during transmission and recover the link layer service data unit. The controller extracts the frame type field from the link layer frame header. If the frame type is identified as a control command frame, the payload data is submitted to the network layer for protocol conversion. The network layer parses the control and address fields, strips the network layer header, and passes the pure application layer payload to the application layer protocol conversion module.

[0128] The application layer module parses the load according to the predefined molded case circuit breaker control application protocol specification, extracting fields such as instruction type code, target device identifier, operation sequence number, timestamp, and security authentication code. The protocol conversion process encapsulates the HPLC carrier network layer protocol into a unified event message format within the controller. This format uses JSON or a binary structure for easier processing by the subsequent security logic module.

[0129] S33. The parsed instruction content is logically coordinated with the line current and voltage protection parameters monitored locally by the controller in real time for judgment. In the coordinated judgment process, the controller firmware constructs the last safety barrier before the remote instruction is executed through a multi-level security verification and real-time electrical parameter cross-verification mechanism, ensuring that the molded case circuit breaker always prioritizes the safety of the local line while responding to remote control. This process is implemented in the controller application layer as an independent safety decision state machine. The state machine includes three main states: instruction parsing state, parameter acquisition state, and decision execution state. Strict switching between states is achieved through event triggering and condition guarding; specifically:

[0130] S331. Instruction content decoding and format verification are completed in instruction parsing mode:

[0131] The controller reads the instruction payload from the event message buffer after the S32 protocol conversion. First, it extracts the 32-byte security authentication code field in the message header. This authentication code is constructed using the HMAC-SHA256 algorithm. The key is stored in the fuse bit protection area of ​​the controller's built-in security chip or MCU. The key length is 256 bits and cannot be read through the software interface.

[0132] The controller inputs all bytes of the instruction payload, except for the authentication code, along with the security key into a hardware encryption coprocessor or a software-implemented encryption library, recalculates the HMAC value, and compares it bit by bit with the authentication code carried in the message. If any discrepancy exists, it is immediately determined to be an illegal instruction, triggering a security event log and discarding the message. At the same time, a security verification failure alarm is reported to the network coordinator. The alarm message contains error type code 0x81 and the MAC address of the suspicious source node to prevent man-in-the-middle attacks or replay attacks.

[0133] After successful security authentication, the controller parses the instruction type code field, which is a 1-byte enumeration value. The protocol predefines remote tripping instruction codes as 0x01, remote closing instruction codes as 0x02, parameter configuration instruction codes as 0x03, etc. If the instruction type code is not within the valid enumeration set, the controller determines that the protocol version is incompatible or the message is corrupted, terminates the process, and records a protocol error log.

[0134] The controller then extracts the target device identifier field, which is a 6-byte MAC address. It performs a bitwise XOR operation with the MAC address of this node. If the result is non-zero, it is determined that the address is incorrect, which may be caused by abnormal network layer forwarding logic. The controller also terminates the process and reports an address mismatch alarm to avoid misoperation of other nodes.

[0135] Finally, the controller reads the operation sequence number field, a 32-bit unsigned integer using a monotonically increasing mechanism. The controller reads the sequence number from the sequence number record area of ​​non-volatile memory, requiring the current sequence number to be strictly greater than the historical value with the difference not exceeding a reasonable window size. The window size is typically set to 1000 to prevent message replay or sequence number overflow / wrap-around attacks. If the sequence number verification passes, the controller transfers the instruction content to the internal register of the security decision state machine and triggers a state transition event to enter the parameter acquisition state.

[0136] S332. Local electrical quantity monitoring is executed in parallel during parameter acquisition:

[0137] The controller initiates the built-in high-precision current sensor data acquisition thread. This sensor employs a Rogowski coil structure, with the coil wound around the current-carrying conductor of the molded case circuit breaker. The induced electromotive force, after being conditioned by an integrator circuit and a programmable gain amplifier, is input to the MCU's built-in 12-bit or 16-bit ADC channel. The ADC sampling rate is configured to 64 or 128 points per power frequency cycle. The sampling clock is synchronously triggered by the zero-crossing detection circuit of the carrier module, ensuring strict alignment between the sampling sequence and the voltage waveform. The current sample value is then digitally low-pass filtered and RMS calculated to obtain the RMS value I of the line current. rms .

[0138] The controller synchronously acquires the phase voltage signal output by the voltage sensor. The voltage sensor uses a precision resistor divider network with a division ratio set to 200:1 or 300:1. The divided signal is input to an ADC channel independent of the current channel, with the sampling rate consistent with the current channel. The voltage sample value is used to calculate the effective voltage value V. rms .

[0139] After obtaining the electrical quantity, the controller compares the effective value of the current with the preset overcurrent trip threshold step by step. The overcurrent protection threshold is set according to the rated current In of the circuit breaker and the protection characteristic curve. The long-delay protection threshold is generally 1.05In to 1.15In, corresponding to an action time of more than 60 seconds; the short-delay protection threshold is set to 3In to 10In, with an action time of 0.1 seconds to 1 second; and the instantaneous trip threshold is set to 10In to 20In, with an action time of less than 20 milliseconds.

[0140] The controller employs hysteresis comparator logic with a 5% to 10% hysteresis band to prevent protection logic jitter caused by current fluctuations at threshold boundaries. The effective voltage value is compared with the undervoltage and overvoltage trip thresholds. The undervoltage threshold is typically set to 85% of the rated voltage, and the overvoltage threshold to 110%, also configured with a hysteresis window. The comparison result generates three Boolean flags: Overcurrent Limit Flag I. fault Undervoltage over-limit indicator V under Overvoltage limit indicator V over Each flag bit is active high and stored in a specific bit field of the security decision register.

[0141] S333. Safe logic decision-making implements comprehensive decision-making based on Boolean algebra in the decision execution state:

[0142] The decision logic expression is hardcoded in the controller firmware as: Drive Enable = Instruction ValidAND (NOT I fault AND (NOT V) under AND (NOT V) over ), where Instruction Valid is the conjunct result of all validation items in S331, I fault V under V over This is the over-limit flag output by the S332 comparer. The Drive Enable signal is at a logic high level only when the instruction validity flag is true and all electrical quantity over-limit flags are false, indicating that the safety logic decision is to allow execution.

[0143] This decision mechanism ensures that local protection functions always have the highest priority, and any electrical fault condition can unconditionally block remote operation. If the decision result is prohibition, the controller immediately terminates the subsequent drive command generation process and sends a local protection priority alarm message to the network coordinator through the alarm reporting thread. The alarm message adopts an event-driven model, is constructed at the protocol conversion layer, and includes alarm type code 0x42, over-limit parameter type code, over-limit value, and a timestamp accurate to milliseconds. The message is inserted and sent through the HPLC carrier module when the channel is idle, ensuring that the network side is promptly notified of remote control interception events, providing diagnostic basis for maintenance personnel to adjust protection settings or remote control strategies.

[0144] S334. Driver instruction generation is triggered when the decision result is that execution is allowed. The controller generates a local driver instruction word based on the instruction type parsed from S331:

[0145] For remote tripping commands, the controller generates a tripping drive command word, which is a 16-bit binary code. Bits 15-12 are set to the operation type code 0x1, bits 11-8 set the tripping speed level (levels 1 to 5 correspond to action delays of 10 milliseconds to 50 milliseconds respectively), and bits 7-0 set the drive pulse width parameter. The actual pulse width is the register value multiplied by 0.5 milliseconds, with an adjustable range of 8 milliseconds to 128 milliseconds. After the command word is generated, the controller writes it to the drive control register and triggers the GPIO output enable signal.

[0146] For remote closing commands, a closing drive command word is generated. The operation type code is set to 0x2, bits 11-8 set the motor speed level, and bits 7-0 set the torque limit parameters to prevent motor burnout due to mechanical jamming during closing. The drive command word is transmitted to the subsequent power drive circuit through an opto-isolator to achieve strong and weak current isolation.

[0147] If the judgment result is prohibition of execution, the controller will not generate any drive instruction word, the drive control register will remain at the reset value, and the GPIO output will remain at a low level to ensure that the tripping mechanism and the electric operating mechanism do not move.

[0148] Meanwhile, the controller can selectively record detailed event logs of the remote control request being blocked by local protection. The log content includes the source node address, command type, over-limit parameter value, and decision time. The log entries are stored in a circular buffer of the Flash memory, which can save the most recent 1,000 records, and support maintenance personnel to read and analyze them through the maintenance interface.

[0149] S34. The drive signal conversion and output stage is executed at the controller hardware layer:

[0150] The local drive command word is first sent to the drive signal generation module. If the module is performing a tripping operation, it triggers the thyristor or IGBT power device to conduct a drive pulse of 50 to 200 milliseconds. The pulse current amplitude is set according to the rated parameters of the trip coil, usually 2 to 5 amps. The rise time of the pulse leading edge is controlled within 1 millisecond to ensure fast tripping.

[0151] If it is a closing operation, the drive module outputs a PWM signal to the DC motor drive chip of the electric operating mechanism. The PWM frequency is set to 20kHz, and the duty cycle is dynamically adjusted according to the speed parameter in the instruction word. The motor drive current is amplified by the H-bridge circuit and drives the motor to rotate. The circuit breaker contacts are closed through the mechanical transmission mechanism.

[0152] During the drive signal output process, the controller monitors the drive circuit current in real time through the Hall current sensor. If an overcurrent or abnormal circuit breaker position feedback signal is detected, the drive output is immediately cut off and a drive fault is reported to prevent the mechanism from jamming and causing equipment damage.

[0153] After the drive is executed, the controller updates the circuit breaker position status register and sends an operation confirmation message back to the upstream node or network coordinator through the HPLC carrier module. The message carries the operation type, execution result and electrical parameters after the operation, thus completing the entire remote control closed loop.

[0154] S4. Based on the execution results of the optimal communication path and channel state change data, evaluate communication performance and trigger node parameter optimization or network resource reconfiguration; specifically including:

[0155] S41. Based on the actual execution results of the optimal communication path, the controller calculates the key performance indicators for this communication. These performance indicators include at least the command transmission success rate and end-to-end transmission latency. Simultaneously, it compares the channel state change data acquired before and after the communication. Specifically:

[0156] S411. The timestamp recording mechanism is implemented by the controller's built-in high-precision real-time clock and event capture unit. The start timestamp of the remote control command reception is automatically recorded by hardware when the HPLC carrier module completes frame synchronization at the physical layer and triggers a reception interrupt, with a time accuracy of microseconds. The drive signal generation timestamp is obtained by software calling the system time function at the instant the S334 step determines that execution is allowed and the drive command word is written to the control register, with an accuracy of milliseconds. The final application layer confirmation timestamp is recorded when the controller receives and parses the confirmation message for the execution result of this command from the network side. If an end-to-end confirmation mechanism is used, the message is sent by the source node or network coordinator after receiving the drive execution feedback. If a hop-by-hop confirmation mechanism is used, the relay node forwards the upper-layer confirmation.

[0157] End-to-end transmission delay is expressed by the formula ΔT = Tconfirm - T receive The calculation shows that T confirm For application layer confirmation timestamp, T receive The timestamp for receiving the instruction is displayed, and the result is in milliseconds.

[0158] The command transmission success rate is calculated using a dual criterion: the data packet correctness criterion is based on the CRC check results of the physical layer and the link layer. If the response signal does not report any CRC error during S32 demodulation and decoding, this criterion is true. The integrity criterion is based on whether the application layer has received a final acknowledgment. If an acknowledgment message is received and the acknowledgment sequence number matches the sent command sequence number, the integrity criterion is true. The transmission success rate is a binary indicator for a single communication, recorded as 100% for success and 0% for failure.

[0159] The controller writes the end-to-end transmission delay ΔT and command transmission success rate into the corresponding fields of the performance evaluation record.

[0160] S412. Channel state change comparison requires the controller to perform a channel state snapshot operation once before the start of the current communication transaction and once after its completion. The snapshot triggering timing is controlled by the communication transaction state machine: the start snapshot is captured before the carrier module enters the listening mode in S31. At this time, the controller copies the current values ​​of the signal-to-noise ratio and bit error rate of the links involved in the optimal communication path from the real-time channel state parameter vector maintained in S14 and stores them in the initial snapshot buffer in RAM; the completion snapshot is captured after the drive signal is output and the position feedback is confirmed in S34. At this time, the latest value of the corresponding link in the real-time channel state parameter vector is read again and stored in the latest snapshot buffer.

[0161] The changes in key channel parameters are calculated using vector difference: Path signal-to-noise ratio change ΔSNR = SNR latest -SNR initial SNR initial and SNR latest These represent the path signal-to-noise ratio at the start and end of the snapshot, respectively; the path bit error rate change ΔBER = BER latest - BER initial BER initial and BER latest These represent the path error rate (BER) at the start and end of the snapshot, respectively. If ΔSNR is positive and greater than 3dB, it indicates a significant improvement in channel quality during communication, possibly due to load shedding or the disappearance of the interference source. If ΔSNR is negative and less than -3dB, it indicates channel degradation, possibly caused by load addition or sudden interference. The ΔBER trend is analyzed similarly. The controller stores ΔSNR and ΔBER in floating-point format in the channel change field of the performance evaluation record and records the direction of change.

[0162] S413. The associated storage and tagging operation integrates discrete timestamps, success rates, and channel variations into a structured performance evaluation record.

[0163] The record format uses a fixed-length binary structure, including a path ID field, which is carried by the path descriptor generated by S23 and uniquely identifies the optimal path used in this communication; a timestamp triplet field, with each timestamp occupying 4 bytes of Unix millisecond count; a success rate field occupying 1 byte, where 0 indicates failure and 1 indicates success; a signal-to-noise ratio change and a bit error rate change each occupying 4 bytes of IEEE 754 floating-point numbers; and finally, a 4-byte CRC checksum is appended to ensure record integrity.

[0164] The record is written to the ring-shaped performance log area of ​​the controller's Flash memory. This area can cyclically store the most recent 500 records and supports power-loss retention. Simultaneously, the record is mapped in read-only format to the Network Management Information Base (MIL), allowing the network coordinator to periodically read it via the SNMP protocol.

[0165] S42. The controller first checks the relay node list field in the optimal communication path descriptor for this communication. If the MAC address of this node appears in the relay node sequence of the path and is not the last hop, then it is confirmed that this node has undertaken the relay forwarding task in this communication.

[0166] After confirming the relay's identity, the controller extracts the performance evaluation record generated by S413 and focuses on analyzing two key indicators: command transmission success rate and end-to-end latency. If the success rate is 100% and the latency is below the preset excellent threshold, the relay performance is considered excellent. If the success rate is 100% but the latency is high, exceeding 500 milliseconds, the performance is considered acceptable but requires optimization. If the success rate is below 100%, the performance is considered unacceptable, triggering the parameter optimization process.

[0167] The optimization decision-making adopts a rule engine or a lightweight machine learning model, and the input features include ΔSNR, ΔBER, success rate, latency, and relay load concurrency.

[0168] The carrier transmit power optimization rule is as follows: if ΔSNR is less than -5dB and the relay load is normal, the transmit power is increased by 1 level. The power levels are usually divided into 0 to 15 levels, with an increment of 1dBm per level, and the maximum is no more than 15 levels; if ΔSNR is greater than 5dB and the power level is greater than 8, the power level is reduced by 1 level to reduce interference to other nodes.

[0169] Relay forwarding priority optimization is based on latency performance: if the latency exceeds the excellent threshold, the priority is increased by 1 level. The priority range is from 0 to 7. The higher the value, the higher the priority is processed, thus shortening the relay queue waiting time.

[0170] Channel access listening time optimization is based on bit error rate (BER) changes: if ΔBER is positive and exceeds 1×10 -3 The CSMA / CA listening time of the carrier module is extended by 20%, increasing the backoff opportunity to reduce collisions.

[0171] The optimized parameters are immediately written to the corresponding register of the carrier module and take effect in subsequent relay tasks. The controller synchronously updates the node configuration parameter area in the Flash storage to ensure that the optimized parameters are retained after a power failure and restart.

[0172] S43. Triggered in communication failure scenarios. Failure determination is based on the success rate field recorded in S413. If the success rate is 0%, the failure handling process is initiated.

[0173] Failure type identification is achieved by analyzing the specific stage of communication transaction termination: if no valid signal is received after the S31 listening timeout, the failure type is marked as path unreachable; if the CRC error rate exceeds 50% during the S32 demodulation and decoding process, it is marked as severely degraded channel; if the S333 security decision is blocked due to electrical fault, it is marked as local protection block.

[0174] The network optimization suggestion message is constructed using the TLV format. The type field occupies 1 byte, identifying the message type as an optimization suggestion; the length field occupies 1 byte, indicating the length of subsequent data; and the value field contains multiple nested TLV structures. The specific encapsulated content includes: a phase line position sub-TLV, filled with the phase line code of this node fixed in S13; a real-time channel state parameter sub-TLV, filled with the original values ​​of SNR, bit error rate, and signal strength at the time of failure; a communication failure type sub-TLV, filled with the identified failure type code; and an optimal communication path information sub-TLV, filled with the complete binary content of the path descriptor generated in S23, including the path ID, relay node list, and score value, facilitating the network coordinator's reproduction of the path decision context. The total message length is controlled within 128 bytes to accommodate the limited bandwidth of the HPLC carrier network.

[0175] The reporting timing is managed by the scheduler in the controller firmware. The preset periodic reporting timing is implemented through the RTC timer, with a default period of 15 minutes. The periodic reporting mechanism ensures that even without immediate failure, the network coordinator can continuously obtain the operating status and optimization suggestions of each node. The channel idle detection reporting mechanism is implemented through the CSMA / CA carrier sensing function of the carrier module. When the controller detects that the channel occupancy rate is below 20% for 500 milliseconds, it determines that the channel is idle and immediately triggers the reporting process to avoid message conflicts.

[0176] The reporting process submits optimization suggestion messages to the transmission queue of the HPLC carrier module, sets the target address to the dedicated address of the network coordinator, sets the transmission priority to the highest, adopts a reliable transmission mode, and enables end-to-end confirmation.

[0177] After receiving the message, the network coordinator parses the content and updates the global network topology database. Based on the failure type and path information, it adjusts routing algorithm parameters, such as reducing the score weight of failed paths, increasing the candidate set of relay nodes, or triggering network-level frequency replanning, thereby achieving dynamic reconfiguration of communication resources. The controller starts an acknowledgment waiting timer after sending the message. If no acknowledgment is received from the coordinator within 3 seconds, the message is retransmitted in the next idle period, up to a maximum of 3 retransmissions, ensuring that optimization suggestions are reliably delivered.

[0178] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0179] This represents a leap from passive response to proactive sensing and intelligent decision-making, fundamentally ensuring the reliability of cross-phase communication. Through proactive network topology sensing and precise phase line location methods, the molded case circuit breaker (MCCB) can autonomously and accurately identify its position in the three-phase power grid and simultaneously acquire detailed channel state parameters. This provides crucial input for quantitative bottleneck identification and intelligent relay path decision-making mechanisms. When cross-phase direct communication becomes unreliable due to dynamic channel degradation, the system can automatically and quickly calculate and switch to a relay path through the optimal phase node, thereby proactively avoiding communication bottlenecks. This ensures the stability and robustness of remote control command transmission channels in various complex power grid environments and solves the problem of control failure caused by unpredictable communication quality.

[0180] An inherently safe collaborative mechanism between communication control and local protection has been established, eliminating the risk of malfunctions in protection blind spots. Based on the command-protection collaborative judgment logic, before executing any remote opening or closing command, the system forcibly performs a logical AND operation between the command validity verification and the locally acquired line current, voltage, and other protection parameters. This fundamentally prevents the dangerous execution of remote commands in critical states where there are already potential faults such as overcurrent or short circuits on the line, and the local protection should have triggered but has not yet tripped. This achieves a deep and safe integration of remote control functions and the core protection functions of the circuit breaker, upgrading the traditional independent "parallel" structure to a "series" structure with safety interlocking, significantly improving the inherent safety level of the intelligent power distribution system.

[0181] This creates an optimized closed loop from single-node execution to network self-learning, enabling continuous improvement in the overall communication efficiency of the system. Each node automatically evaluates its communication performance and analyzes the correlation of channel changes after completing a single control transaction. At the node level, relay nodes can adaptively optimize their own communication parameters to improve subsequent relay efficiency; at the network level, nodes can report structured medical records containing topology, channel details, and failure information. This allows the network coordinator to obtain a precise global view, thereby enabling network-level reconfiguration of communication resources. This innovation allows the system to move beyond simply completing a single control task, learning, diagnosing, and expanding optimization from each operation, effectively addressing the dynamic migration of local communication bottlenecks, and achieving continuous self-evolution of the resilience and efficiency of the entire power distribution IoT communication system.

[0182] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the present invention, but these should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0183] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A control method for a molded case circuit breaker based on HPLC power line communication, characterized in that, The controller of the molded case circuit breaker integrates an HPLC carrier module, and the method includes: The HPLC carrier module actively senses and acquires the phase line position and real-time channel status parameters of the molded case circuit breaker. Based on the phase line position and real-time channel state parameters, the optimal communication path for executing remote control commands is dynamically determined; The signal is converted according to the optimal communication path, and the converted instruction is judged in conjunction with the local protection logic to generate and execute the drive signal. Based on the execution results of the optimal communication path and channel state change data, the communication performance is evaluated and node parameter optimization or network resource reconfiguration is triggered, specifically including: The controller calculates key performance indicators for this communication based on the actual execution results of the optimal communication path, and compares the channel state change data acquired before and after the communication. Specifically, the controller records the key event timestamps of this communication transaction corresponding to the optimal communication path, and calculates the end-to-end transmission delay based on the timestamps. Simultaneously, based on the correctness and integrity of the data packets received during this communication process and whether final application layer confirmation is received, the controller calculates the command transmission success rate. The controller retrieves the initial channel state parameter snapshot related to the optimal communication path at the instant before the start of this communication transaction, and the latest channel state parameter snapshot at the instant after the completion of the communication transaction. The initial and latest channel state parameter snapshots are compared to calculate the changes in key channel parameters. The controller associates and stores the command transmission success rate and end-to-end transmission delay with the changes in key channel parameters, forming a complete performance evaluation record containing path identifiers, performance indicators, and channel changes. If the assessment confirms that the communication successfully used this node as a relay node, the controller will adaptively optimize at least one communication parameter of this node based on key performance indicators and channel state change data, and apply the optimized parameter to subsequent relay tasks. If the assessment confirms that the communication failed due to a channel bottleneck, the controller generates a network optimization suggestion message. The controller then reports the network optimization suggestion message to the network coordinator through the HPLC carrier module at a preset periodic reporting time or when the channel is detected to be idle.

2. The method for controlling a molded case circuit breaker based on HPLC power line communication according to claim 1, characterized in that, The HPLC carrier module actively senses and acquires the phase line position and real-time channel state parameters of the molded case circuit breaker, specifically including: When the molded case circuit breaker is powered on or reaches a preset cycle, the controller drives its integrated HPLC carrier module to broadcast a specific topology detection signal to the three-phase four-wire line of the low-voltage distribution network. The controller listens for and receives response signals from the network coordinator or other adjacent molded case circuit breakers to topology probe signals; By analyzing the phase information contained in the response signal and combining it with the local three-phase voltage phase difference detected by the HPLC carrier module, the specific phase line position of this node is calculated and determined. During the interaction of the topology detection and response signals, the real-time channel state parameters of the current intra-phase communication and cross-phase link are read and obtained synchronously from the physical layer and link layer of the HPLC carrier module. The parameters include at least bit error rate, signal-to-noise ratio and signal strength.

3. The method for controlling a molded case circuit breaker based on HPLC power line communication according to claim 2, characterized in that, The calculation and determination of the specific phase line position of this node specifically includes: From the response signal, the identifier of the source node that sent the response signal and its phase information can be parsed out, or the phase sequence information of each node in the routing path through which the response signal travels from the network coordinator to this node can be parsed out. The controller integrates the zero-crossing detection function built into the HPLC carrier module, synchronously detects and acquires the phase angle of the local three-phase voltage relative to the neutral line, and calculates the voltage phase difference between each pair. The phase information is matched and logically deduced with the local voltage phase relationship. If the response signal clearly indicates that the source node is a specific phase, the signal strength and local phase difference are combined to confirm whether the node is in the same phase as the source node. If the response signal contains a routing path phase sequence, the specific phase line connected to the node in the three-phase topology is inferred based on the phase relationship of adjacent nodes in the sequence and the local voltage phase difference.

4. The method for controlling a molded case circuit breaker based on HPLC power line communication according to claim 1, characterized in that, Based on the phase line position and real-time channel state parameters, the optimal communication path for executing remote control commands is dynamically determined, specifically including: Determine whether the source node and local node of the remote control command are on the same phase line; if so, pre-select the direct in-phase communication path as a candidate path; otherwise, proceed to the cross-phase path decision process. In the cross-phase path decision-making process, if it is determined that there is a bottleneck in cross-phase communication, then the relay path decision is initiated. Based on the real-time channel state parameters, at least one node with the optimal channel state is selected from other known nodes located on different phase lines as an out-of-phase intermediate node, and an optimal communication path for signal relay forwarding through the out-of-phase intermediate node is determined.

5. The method for controlling a molded case circuit breaker based on HPLC power line communication according to claim 4, characterized in that, If a bottleneck is determined to exist in cross-phase communication, a relay path decision is initiated, specifically including: The cross-signal-to-noise ratio in the real-time channel state parameters is compared with a dynamic first preset threshold, and the cross-phase bit error rate is compared with a dynamic second preset threshold; if the cross-signal-to-noise ratio is continuously lower than the first preset threshold for a first preset duration, or the cross-phase bit error rate is continuously higher than the second preset threshold for a second preset duration, a bottleneck confirmation signal is generated. Simultaneously with the generation of the bottleneck confirmation signal, the relay path decision algorithm is activated by combining the phase line position information of the local node and adjacent nodes. The algorithm takes the real-time channel state parameters and phase line position information as input and begins to select the optimal relay node and calculate the path.

6. The method for controlling a molded case circuit breaker based on HPLC power line communication according to claim 5, characterized in that, The decision to determine an optimal communication path for signal relay forwarding via an out-of-phase intermediate node specifically includes: Based on the phase line position of the molded case circuit breaker and the known network topology information, all adjacent nodes that are on different phase lines from the local node and are recorded as valid relay candidates are selected to form an initial set of relay candidate nodes. For each candidate node in the initial relay candidate node set, real-time channel state parameters are extracted, and a comprehensive channel evaluation value is calculated. The comprehensive channel evaluation values ​​of all candidate nodes are compared, and one or more candidate nodes with the highest comprehensive channel evaluation values ​​are determined as the nodes with the optimal channel state. These nodes are then used as inter-phase intermediate nodes to generate one or more relay forwarding paths that explicitly include the source node, relay node, and target node. The path with the highest comprehensive evaluation value is then determined as the optimal communication path.

7. The control method for a molded case circuit breaker based on HPLC power line communication according to claim 1, characterized in that, Based on the optimal communication path, signal conversion is performed, and the converted instructions are collaboratively judged with local protection logic to generate and execute drive signals, specifically including: The controller calls the HPLC carrier module to listen for and receive signals according to the optimal communication path; The controller demodulates, decodes, and converts the received signals to extract the effective data payload carrying remote control commands or relay forwarding commands. The parsed instruction content is logically coordinated with the line current and voltage protection parameters monitored locally by the controller in real time to generate corresponding local drive instructions. The local drive command is converted into a drive signal with specific timing and power, and output to the tripping mechanism or electric operating mechanism of the molded case circuit breaker to perform the corresponding operation.

8. The control method for a molded case circuit breaker based on HPLC power line communication according to claim 7, characterized in that, The parsed instruction content is logically coordinated with the line current and voltage protection parameters monitored locally by the controller in real time to generate corresponding local drive instructions, specifically including: The instruction content is decoded and its format is verified to confirm whether it is a valid remote tripping or closing command that conforms to a predefined protocol; if not, the process is terminated and the instruction content is discarded. While verifying the validity of the instruction content, the line current value and voltage value collected by the current sensor and voltage sensor built into the controller are acquired in real time. The line current value is compared with the preset overcurrent trip threshold, and the voltage value is compared with the preset undervoltage or overvoltage trip threshold. The decision to allow execution is made only when the instruction is confirmed to be a valid opening and closing command, and the comparison results confirm that all line current and voltage values ​​have not reached their respective protection tripping thresholds; The controller generates a corresponding local drive command for driving the tripping or closing operation based on the specific type of the instruction content, only when the security logic decision result is that execution is allowed; if the security logic decision result is that execution is prohibited, the controller does not generate a drive command and may choose to report an alarm message with local protection priority.

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