A method and system for reliable multi-service communication access in power grids that integrates broadband and narrowband bandwidth.

Abstract

This invention relates to the field of power grid communication technology, and discloses a reliable communication access method and system for multi-service power grids that integrates broadband and narrowband bandwidths. The method includes: identifying emergency flags of multi-service data frames and injecting fast bypass; querying the availability of both broadband and narrowband channels and prioritizing the scheduling of emergency data frames; monitoring the interference status of both broadband and narrowband channels and marking interference suppression; detecting the high-frequency signal-to-noise ratio gap under the interference status of the two channels; preprocessing emergency data frames into minimized units and performing micro-burst transmission during the interference gap; detecting channel recovery and resuming multi-service data transmission. This invention solves the problem of reliable transmission of emergency protection commands when both 5G broadband wireless channels and HPLC narrowband power line channels are simultaneously disturbed.

Description

Technical Field

[0001] This invention relates to the field of power grid communication technology, and more specifically, to a reliable communication access method and system for multi-service power grids that integrates broadband and narrowband bandwidth. Background Technology

[0002] In the low-voltage power distribution communication access scenario that integrates 5G and HPLC, the access terminal carries data frames of various service types, such as periodic metering data acquisition, real-time control commands, and fault protection signals. These multi-service data frames share the 5G broadband wireless channel and the HPLC narrowband power line channel for transmission and access. Among them, the end-to-end latency requirement for real-time protection services is less than 20ms.

[0003] In existing technologies, when a high-voltage switching operation or fault arc occurs in the primary equipment of the power grid, the transient electromagnetic pulse will simultaneously cause sudden radio frequency interference to the 5G broadband wireless channel and impulsive noise to the HPLC narrowband power line channel, resulting in simultaneous degradation of both channels in a short period of time. Existing 5G and HPLC fusion access methods mainly adopt load balancing strategies based on the current channel status and dual-channel redundant transmission strategies.

[0004] However, existing technologies have the following drawbacks: First, the routine service classification and channel optimization routing process itself introduces processing delays of tens of milliseconds, making it impossible to meet the ultra-low latency requirements for real-time protection emergency commands. Second, load balancing strategies based on the current channel status cannot predict impending electromagnetic interference events, causing data frames already scheduled to the channel to fail to transmit during sudden interference. Third, the dual-channel redundant transmission strategy fails when both channels are simultaneously subjected to transient electromagnetic pulse interference, leading to a transmission deadlock for emergency commands due to the lack of available channels. Fourth, the unified buffering strategy for waiting for interference to subside does not differentiate between the urgency levels of services, causing emergency protection commands to wait for channel recovery along with ordinary data frames. These drawbacks result in existing converged access methods lacking effective and reliable communication guarantees under extreme conditions where both channels are simultaneously disturbed and the ultra-low latency requirements for real-time protection overlap, making it impossible to guarantee the reliable delivery of emergency protection commands within the required timeframe. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or existing power grid multi-service communication access methods, the present invention is proposed.

[0007] To address the aforementioned technical problems, this invention provides the following technical solution: a reliable communication access method for multi-service communication in a power grid with converged broadband and narrowband bandwidth, comprising the following steps:

[0008] Perform a fast scan of the frame header for the multi-service data frames arriving at the power grid communication access terminal, extract the frame type field and compare it with the pre-stored real-time control and protection service feature code, and output the emergency flag bit;

[0009] When the emergency flag is set, the multi-service data frame is injected into the low-latency transmission buffer, skipping the regular service classification and channel optimization routing process; the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel are read in parallel to obtain the signal-to-noise ratio index value and determine whether there is an available channel;

[0010] When an available channel exists, the channel with the best transmission delay index is selected as the target channel. Preemptive scheduling is performed on the urgent data frames in the low-latency transmission buffer and they are sent immediately. The real-time signal-to-noise ratio (SNR) index of the two channels is continuously monitored. When the absolute value of the SNR change of either channel exceeds the threshold for a sharp drop and the SNR index value drops below the minimum transmission SNR threshold, the channel is marked to enter the interference suppression state.

[0011] When both channels are in interference suppression mode and there are urgent data frames to be sent in the low-latency transmission buffer, the high-frequency signal-to-noise ratio detection mode is activated, and instantaneous signal-to-noise ratio sampling is performed in parallel at microsecond-level sampling intervals to identify the signal-to-noise ratio recovery gap and calculate its duration.

[0012] Perform minimal preprocessing on emergency data frames, stripping unnecessary protocol overhead fields while retaining instruction opcodes, target device addresses, and cyclic redundancy check codes to generate minimal transmission units;

[0013] When the duration of the signal-to-noise ratio recovery gap is detected to meet the minimum transmission duration required by the minimum transmission unit, the minimum transmission unit is injected into the corresponding channel to perform micro-burst transmission; when the signal-to-noise ratio index value of the channel in the interference suppression state recovers to above the minimum transmission signal-to-noise ratio threshold and continues to reach the stable judgment duration, the interference suppression state is lifted, and the suspended ordinary service data frames are resumed according to the transmission breakpoint location and transmission context information.

[0014] Furthermore, the processing when the emergency flag is set is performed using an interrupt-driven fast channel bypass method; when the frame header fast scanning circuit detects that the frame type field matches the feature code of the real-time control protection service, it generates a hardware interrupt signal. After the processor of the power grid communication access terminal responds to the hardware interrupt signal, it directly writes the storage pointer of the current multi-service data frame into the tail register of the low-latency transmission buffer, skipping the calls to the regular service classification module and the channel optimization routing module.

[0015] Furthermore, the preemptive scheduling includes: sending a transmission pause command to the physical layer of the target channel; the physical layer stops transmitting after completing the currently transmitting physical layer frame and returns the byte offset of the transmitted data to the scheduling module; the scheduling module stores the byte offset along with the modulation and coding scheme, channel coding parameters, and target receiving address in the breakpoint record table; then, it submits the transmission request of the emergency data frame to the physical layer; the physical layer reconfigures the modulation encoder and channel encoder according to the transmission parameters of the emergency data frame and then begins to transmit the emergency data frame.

[0016] Furthermore, the real-time signal-to-noise ratio index of the continuously monitored dual channels also includes: receiving operation forecast information and fault warning signals from primary power grid equipment, and parsing the operation type, equipment location, and expected execution time contained therein; obtaining the corresponding typical electromagnetic pulse duration by looking up a table according to the operation type, and calculating the electromagnetic wave propagation delay based on the electrical distance between the equipment location and the power grid communication access terminal; adding the electromagnetic wave propagation delay to the expected execution time as the expected interference start time, and adding the typical electromagnetic pulse duration to the expected interference start time as the expected interference end time, thereby generating an interference event prediction time window.

[0017] Furthermore, at a preset lead time before the arrival of the interference event prediction time window, a preventive buffering operation is performed on the ordinary service data frames to be sent in the transmission queue, moving the ordinary service data frames to be sent from the transmission queue into the preventive buffer area, and suspending the scheduling of new ordinary service data frames to the 5G broadband wireless channel and the HPLC narrowband power line channel.

[0018] Furthermore, the identification of the signal-to-noise ratio (SNR) rise gap includes: in the instantaneous SNR time series, detecting the rising edge of the SNR value from below the minimum transmission SNR threshold to above or equal to the minimum transmission SNR threshold as the gap start point, and detecting the falling edge of the SNR value from above or equal to the minimum transmission SNR threshold to below the minimum transmission SNR threshold as the gap end point; the duration of the SNR rise gap is the time difference between the gap end time and the gap start time.

[0019] Furthermore, after the micro-burst transmission, the process further includes: listening for transmission confirmation responses in parallel on the 5G broadband wireless channel and the HPLC narrowband power line channel; if a transmission confirmation response is received within the set timeout window, the emergency data frame is marked as successfully delivered and removed from the low-latency transmission buffer; if no transmission confirmation response is received within the set timeout window, the minimized transmission unit is marked as pending retransmission, and retransmission is performed in the next signal-to-noise ratio recovery gap that meets the duration requirement; when the cumulative retransmission count of the same minimized transmission unit reaches the upper limit of the cumulative retransmission count, the retransmission operation is stopped and a delivery failure alarm message is output to the upper-level management system.

[0020] Furthermore, when the 5G broadband wireless channel and the HPLC narrowband power line channel simultaneously detect the signal-to-noise ratio recovery gap that meets the duration requirement, a minimized transmission unit is injected simultaneously into the 5G broadband wireless channel and the HPLC narrowband power line channel to perform parallel micro-burst transmission. The first channel to receive the transmission confirmation response is marked as a successful delivery.

[0021] Furthermore, after the interference suppression state is lifted, the process further includes: scheduling ordinary service data frames in the preventive buffer to the recovery channel for transmission in order of their timestamps from earliest to latest; after both the 5G broadband wireless channel and the HPLC narrowband power line channel are restored to available status, performing dual-channel load balancing scheduling on the remaining ordinary service data frames in the preventive buffer, and allocating the ordinary service data frames to the channel with lower load for transmission based on the current transmission rate and queuing depth of each channel.

[0022] This invention also discloses a broadband and narrowband converged power grid multi-service reliable communication access system, comprising:

[0023] The emergency flag identification module is used to perform a fast scan of the frame header of the multi-service data frames arriving at the power grid communication access terminal, extract the frame type field and compare it with the pre-stored real-time control and protection service feature code to output the emergency flag bit. When the emergency flag bit is set, the multi-service data frame is injected into the low-latency transmission buffer.

[0024] The dual-channel scheduling module is used to read the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel, obtain the signal-to-noise ratio index value and determine whether there is an available channel. When there is an available channel, the channel with the best transmission delay index is selected to perform preemptive scheduling on the emergency data frame and send it immediately.

[0025] The interference monitoring module is used to continuously monitor the real-time signal-to-noise ratio (SNR) of the two channels. When the absolute value of the SNR change of any channel exceeds the threshold of sharp drop and the SNR value drops below the minimum transmission SNR threshold, the channel is marked to enter the interference suppression state.

[0026] The high-frequency detection module is used to start the high-frequency signal-to-noise ratio detection mode when both channels are in the interference suppression state and there are urgent data frames to be sent in the low-latency transmission buffer. It performs instantaneous signal-to-noise ratio sampling in parallel at microsecond-level sampling intervals, identifies the signal-to-noise ratio recovery gap, and calculates its duration.

[0027] The micro-burst transmission module is used to perform minimal preprocessing on emergency data frames to generate minimal transmission units. When the duration of the signal-to-noise ratio recovery gap is detected to meet the minimum transmission duration required for the minimal transmission unit, the minimal transmission unit is injected into the corresponding channel to perform micro-burst transmission.

[0028] The channel recovery module is used to release the interference suppression state when the signal-to-noise ratio index value of the channel in the interference suppression state is restored to above the minimum transmission signal-to-noise ratio threshold and continues to be stable for a certain period of time. It then resumes the transmission of suspended ordinary service data frames based on the transmission breakpoint location and transmission context information.

[0029] The beneficial effects of this invention are:

[0030] This invention eliminates the processing delay introduced by the conventional service classification and channel optimization routing process through a fast frame header scanning and interrupt-driven fast bypass mechanism, compressing the identification and scheduling delay of emergency data frames from tens of milliseconds to microseconds. By receiving power grid primary equipment operation warning information to generate an interference event prediction time window and performing preventive caching operations, it avoids invalid transmission of ordinary service data frames during interference. By identifying the brief signal-to-noise ratio recovery gap between transient electromagnetic pulses through a high-frequency signal-to-noise ratio detection mode, and preprocessing emergency data frames into micro-burst transmissions within the gap by minimizing the transmission unit, it overcomes the transmission deadlock of emergency commands when both channels are simultaneously unavailable. By restoring transmission at the transmission breakpoint location and using a timestamp priority scheduling mechanism, it restores the complete access of ordinary service data, solving the problem of reliable communication guarantee under extreme conditions where both channels are simultaneously disturbed and the real-time protection ultra-low latency requirement overlaps. It achieves the technical effect of ensuring the reachability of emergency protection commands even under continuous disturbance of both channels. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a method for reliable multi-service communication access in a power grid that integrates broadband and narrowband bandwidth, provided in an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram comparing the arrival time and processing delay of multi-service data frames provided in an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram comparing the dual-channel transmission performance indicators provided in the embodiments of the present invention.

[0035] Figure 4 This is a schematic diagram illustrating the change in the signal-to-noise ratio of the dual channels before and after transient electromagnetic pulse interference, provided in an embodiment of the present invention.

[0036] Figure 5This is a schematic diagram of the instantaneous signal-to-noise ratio time series under the high-frequency signal-to-noise ratio detection mode provided in the embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram comparing the data structure before and after the emergency data frame minimization preprocessing provided in an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram of key time nodes in the micro-burst transmission process provided in an embodiment of the present invention.

[0039] Figure 8 This is a schematic diagram of the signal-to-noise ratio monitoring time series of the dual-channel recovery process provided in an embodiment of the present invention.

[0040] Figure 9 This is a schematic diagram of the scheduling statistics of ordinary service data frames in the preventive buffer provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] like Figure 1 As shown, a reliable communication access method for multiple services in a power grid with converged broadband and narrowband bandwidth is provided. It should be understood that the execution subject of this embodiment is a power grid communication access terminal configured with a 5G broadband wireless communication interface and an HPLC narrowband power line communication interface. The power grid communication access terminal has a frame buffer storage area, a low-latency transmission buffer, and a preventive buffer area, and maintains real-time availability status registers for the 5G broadband wireless channel and the HPLC narrowband power line channel respectively.

[0043] The steps of this implementation method are as follows:

[0044] Step 1: Identify the emergency flags of multi-service data frames and inject fast bypass;

[0045] For multi-service data frames arriving at the power grid communication access terminal, a fast frame header scan is performed to extract the frame type field from the frame header. The frame type field is then compared with the pre-stored real-time control and protection service feature codes, and an emergency flag is output. When the emergency flag is set, the multi-service data frame is injected into a reserved low-latency transmission buffer, skipping the regular service classification and channel optimization routing process. When the emergency flag is not set, the multi-service data frame is sent to the regular service classification and channel optimization routing process for processing.

[0046] Furthermore, the aforementioned real-time control and protection service feature codes refer to a predefined set of coded values ​​in the frame type field used to identify real-time protection services, including emergency trip control command feature codes, fault isolation command feature codes, etc. The frame header fast scan only reads the frame type field at a fixed offset position in the multi-service data frame header, without parsing the frame payload content. The comparison operation involves looking up and matching the extracted frame type field values ​​in the set of real-time control and protection service feature codes.

[0047] Furthermore, to reduce the identification delay of the emergency flag to the microsecond level, the processing when the emergency flag is set is executed using an interrupt-driven fast-channel bypass method. Specifically, when the frame header fast scanning circuit detects a match between the frame type field and the feature code of the real-time control and protection service, it generates a hardware interrupt signal. After the processor of the power grid communication access terminal responds to the hardware interrupt signal, it directly writes the storage pointer of the current multi-service data frame into the tail register of the low-latency transmission buffer, skipping the calls to the regular service classification module and the channel optimization routing module, thereby eliminating the queuing waiting time and classification processing time introduced by the regular service classification and channel optimization routing processes.

[0048] Furthermore, the aforementioned interrupt-driven mechanism refers to a working mechanism where an interrupt signal generated by hardware circuitry triggers an immediate response from the processor. When the frame header fast scanning circuit completes the matching of real-time control and protection service signature codes and generates a hardware interrupt signal, the processor suspends the currently executing task and executes the interrupt service routine. The interrupt service routine directly manipulates the registers of the low-latency transmission buffer to write the multi-service data frame pointers. After the interrupt service routine completes its execution, the processor resumes its previous task. This fast-path bypass implemented through the hardware interrupt mechanism avoids the uncertain delays introduced by software polling and task scheduling.

[0049] Step 2: Query the availability of both wideband and narrowband dual channels and prioritize scheduling urgent data frames;

[0050] The system reads the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel, obtains the current signal-to-noise ratio (SNR) values ​​of the 5G broadband wireless channel and the HPLC narrowband power line channel, and determines whether there is an available channel with an SNR that meets the transmission requirements.

[0051] When at least one available channel exists, the current transmission latency metrics of each available channel are compared, and the channel with the best transmission latency metrics is selected as the target channel. Preemptive scheduling is performed on the emergency data frames in the low-latency transmission buffer, the ordinary service data frames being transmitted on the target channel are paused, and the emergency data frames are injected into the target channel for immediate transmission.

[0052] When both the 5G broadband wireless channel and the HPLC narrowband power line channel are unavailable, emergency data frames are retained in a low-latency transmission buffer for subsequent processing.

[0053] Furthermore, the aforementioned real-time availability status register is periodically updated by the channel monitoring module of the power grid communication access terminal, where the recorded signal-to-noise ratio (SNR) value is the channel SNR measurement result within the most recent sampling period. The condition for determining channel availability is that the SNR value is greater than or equal to a preset minimum transmission SNR threshold. ,in The minimum signal-to-noise ratio (SNR) required to ensure that multi-service data frames are transmitted at the target bit error rate. The aforementioned transmission delay metrics include the current queuing depth of the channel and the physical layer transmission rate.

[0054] Furthermore, to ensure the resumption of transmission of suspended normal service data frames after the completion of emergency data frame transmission, the transmission breakpoint location and transmission context information of the suspended normal service data frames on the target channel are recorded during preemptive scheduling. The transmission breakpoint location includes the byte offset of the normally service data frame that has been successfully transmitted, and the transmission context information includes the modulation and coding scheme, channel coding parameters, and target receiving address of the normally service data frame. This recording operation is performed synchronously during the same interruption process that pauses the transmission of normally service data frames.

[0055] Furthermore, the aforementioned preemptive scheduling refers to a scheduling mechanism that immediately interrupts the ongoing transmission of ordinary service data frames on the target channel when an emergency data frame arrives, transferring channel control to the emergency data frame. Specifically, the power grid communication access terminal sends a transmission pause command to the physical layer of the target channel. After completing the currently transmitted physical layer frame, the physical layer stops transmitting and returns the offset of the currently transmitted bytes to the scheduling module. The scheduling module stores the byte offset along with the modulation and coding scheme, channel coding parameters, and target receiving address in the breakpoint record table. Then, it submits the transmission request for the emergency data frame to the physical layer. The physical layer reconfigures the modulation encoder and channel encoder according to the transmission parameters of the emergency data frame and begins transmitting the emergency data frame.

[0056] Step 3: Monitor the interference status of the wideband and narrowband dual channels and mark the interference suppression;

[0057] Continuously monitor the real-time signal-to-noise ratio (SNR) of the 5G broadband wireless channel and the HPLC narrowband power line channel, and calculate the SNR change between adjacent sampling periods. When the signal-to-noise ratio of any channel changes The absolute value exceeds the preset threshold for a sharp drop. Furthermore, the signal-to-noise ratio (SNR) value drops to the minimum transmission SNR threshold. When this occurs, the channel is marked as entering interference suppression state, preventing the scheduling of new multi-service data frames to be sent to the channel.

[0058] in, It represents the change in signal-to-noise ratio between adjacent sampling periods, calculated by subtracting the signal-to-noise ratio of the previous sampling period from the current sampling period's signal-to-noise ratio value. The threshold for a sharp drop; This is the minimum transmission signal-to-noise ratio threshold.

[0059] Furthermore, the aforementioned threshold of sharp decline Used to distinguish between normal channel fading and sudden interference caused by transient electromagnetic pulses, when the signal-to-noise ratio changes... The absolute value exceeds At that time, it is determined that the current channel is being subjected to transient electromagnetic pulse interference.

[0060] Furthermore, in order to perform protective operations in advance before the actual arrival of transient electromagnetic pulse interference, the following steps are also included: receiving operation warning information and fault early warning signals from primary power grid equipment, analyzing the operation type, equipment location, and expected execution time contained therein, and generating interference event prediction time windows for 5G broadband wireless channels and HPLC narrowband power line channels based on the operation type, equipment location, and electrical distance between the power grid communication access terminal. .

[0061] Furthermore, the process of generating the interference event prediction time window is as follows: First, the duration of the typical electromagnetic pulse corresponding to the operation type is obtained by looking up a table according to the operation type. Then, the electromagnetic wave propagation delay is calculated based on the electrical distance between the device location and the power grid communication access terminal. The expected execution time plus the electromagnetic wave propagation delay is used as the expected interference start time. The expected start time of the interference is added to the duration of a typical electromagnetic pulse to determine the expected end time of the interference. Thus, the time window for predicting interference events is obtained. .

[0062] in, This is the predicted start time of the interference; This is the expected end time of the interference; The typical duration of the electromagnetic pulse corresponding to the operation type; This is to delay the propagation of electromagnetic waves.

[0063] Furthermore, the aforementioned power grid primary equipment operation forecast information refers to notification messages issued by the power grid dispatching system or substation monitoring system that contain information about upcoming high-voltage switch operations or equipment switching operations. This forecast information includes operation type, equipment location, and estimated execution time fields. Operation types include circuit breaker opening and closing, disconnector switch operation, capacitor bank switching, etc. The typical electromagnetic pulse duration corresponding to different operation types is stored in the operation type-pulse duration mapping table of the power grid communication access terminal. Electrical distance refers to the equivalent distance between the equipment location and the power grid communication access terminal on the power line network topology. Electromagnetic wave propagation delay is calculated based on the electrical distance and the propagation speed of electromagnetic waves in the power line.

[0064] Furthermore, a preset lead time before the predicted time window for interference events arrives. At any given time, a preventative buffering operation is performed on the ordinary service data frames to be transmitted in the transmission queue. These frames are moved from the transmission queue to the preventative buffer, and the scheduling of new ordinary service data frames to the 5G broadband wireless channel and the HPLC narrowband power line channel is suspended. This preventative buffering operation avoids ordinary service data frames from being scheduled to the channels for invalid transmission during upcoming interference.

[0065] in, This is a preset lead time.

[0066] Step 4: Detect the high-frequency signal-to-noise ratio gap under dual-channel interference conditions;

[0067] When both the 5G broadband wireless channel and the HPLC narrowband power line channel are in interference suppression mode, and there are urgent data frames to be sent in the low-latency transmission buffer, the high-frequency signal-to-noise ratio (SNR) detection mode is activated. In this mode, instantaneous SNR sampling is performed in parallel on both the 5G broadband wireless channel and the HPLC narrowband power line channel at microsecond-level sampling intervals to obtain the instantaneous SNR time series of both channels.

[0068] Analyze the instantaneous signal-to-noise ratio time series to identify instances where the signal-to-noise ratio value rises back to the lowest transmission signal-to-noise ratio threshold. The above continuous time intervals are marked as signal-to-noise ratio (SNR) recovery gaps, and the duration of the SNR recovery gaps is calculated. .

[0069] in, The duration of the signal-to-noise ratio recovery gap is calculated as the time difference between the end and start of the gap.

[0070] Furthermore, the aforementioned microsecond-level sampling interval refers to the signal-to-noise ratio sampling period in the high-frequency signal-to-noise ratio detection mode. The value of the microsecond-level sampling interval should be smaller than the typical pulse interval of transient electromagnetic pulses, so as to capture the brief signal-to-noise ratio recovery window between adjacent pulses.

[0071] Furthermore, the aforementioned signal-to-noise ratio (SNR) recovery gap refers to the brief time window during which the SNR between two adjacent pulses in a transient electromagnetic pulse sequence temporarily recovers to a transmittable level. The identification operation involves detecting when the SNR value in the instantaneous SNR time series drops below a certain threshold. Rise to or above The rising edge of the signal-to-noise ratio is used as the start point of the gap, and the signal-to-noise ratio is detected from a value higher than or equal to the rising edge of the gap. Drop to below The falling edge time is taken as the end point of the gap.

[0072] Furthermore, the aforementioned high-frequency signal-to-noise ratio (SNR) detection mode refers to a special operating mode activated by the channel monitoring module of the power grid communication access terminal when both the 5G broadband wireless channel and the HPLC narrowband power line channel simultaneously enter interference suppression mode. In high-frequency SNR detection mode, the channel monitoring module increases the SNR sampling frequency from milliseconds to microseconds in the conventional monitoring mode, and writes the sampled instantaneous SNR value into a circular buffer in real time to form an instantaneous SNR time series. The identification of the SNR rise interval is achieved through a hardware comparator circuit, which compares each sampled SNR value with... Real-time comparison is performed when multiple consecutive sampled values ​​are higher than or equal to The time-triggered gap detection event records the start time and current time of the gap for calculating its duration. .

[0073] Step 5: Preprocess urgent data frames into minimized units and perform micro-burst transmission during interference gaps;

[0074] For urgent data frames in the low-latency transmission buffer, perform minimal preprocessing, removing unnecessary protocol overhead fields and retaining only the instruction opcode, target device address, and cyclic redundancy check (CRC) code to generate a minimal transmission unit (Transmission Unit). Based on the data length of the minimal Transmission Unit and the physical layer transmission rate of the target channel, calculate the shortest transmission time required for the minimal Transmission Unit. .

[0075] in, To minimize the minimum transmission time required for the transmission unit, the calculation method is to minimize the data length of the transmission unit by dividing the physical layer transmission rate of the target channel.

[0076] When a signal-to-noise ratio (SNR) recovery gap is detected in any channel, and the duration of the SNR recovery gap is... satisfy At that time, a minimized transmission unit is injected into the channel to perform micro-burst transmission.

[0077] Parallel monitoring of transmission confirmation responses is performed on both the 5G broadband wireless channel and the HPLC narrowband power line channel to determine whether the target receiver has successfully received the minimized transmission unit. This is done within a set timeout window. If a transmission acknowledgment response is received, the urgent data frame is marked as successfully delivered and removed from the low-latency transmission buffer. If within the set timeout window... If no transmission acknowledgment response is received within the specified time, the minimized transmission unit will be marked as pending retransmission, and retransmission will be performed during the next detected signal-to-noise ratio recovery gap that meets the duration requirement.

[0078] in, To set a timeout window, the value of the timeout window is determined based on the maximum response delay of the target receiver.

[0079] Furthermore, the aforementioned non-essential protocol overhead fields refer to protocol encapsulation fields that do not affect instruction execution in emergency transmission scenarios, including regular routing information, service classification identifiers, and traffic statistics fields. The reserved instruction opcode is used to instruct the target device to perform specific protection actions, the target device address is used to indicate the device identifier receiving the instruction, and the cyclic redundancy check (CRC) code is used to verify the data integrity of the minimized transmission unit. The minimized transmission unit output from the minimized preprocessing process can be directly recognized and executed by the target device's instruction parsing module without additional decoding or format conversion operations.

[0080] Furthermore, the aforementioned micro-burst transmission refers to a transmission method that completes data transmission within the detected brief signal-to-noise ratio recovery gap. Specifically, when the gap detection event in step 4 is triggered and lasts for a certain duration... When transmission conditions are met, the power grid communication access terminal immediately submits the minimized transmission unit to the physical layer of the target channel. The physical layer begins transmission within the shortest preparation time after the gap start time, employing the channel coding scheme with the highest modulation rate and lowest redundancy supported by the target channel to compress the actual transmission time, ensuring that all data is transmitted before the gap ends. During micro-burst transmission, carrier sensing and backoff waiting are not performed; transmission directly occupies the signal-to-noise ratio recovery gap.

[0081] Furthermore, to prevent resource consumption due to unlimited retransmissions in extreme cases of continuous channel disruption, a maximum limit is set for the cumulative number of retransmissions. When the cumulative number of retransmissions for the same minimum transmission unit reaches... When this happens, the retransmission operation of the minimized transmission unit is stopped, and a delivery failure alarm message is output to the upper-level management system, which then performs subsequent alarm processing.

[0082] in, This represents the maximum number of cumulative retransmissions.

[0083] Furthermore, in order to improve the transmission success probability when gap windows exist in both the 5G broadband wireless channel and the HPLC narrowband power line channel, based on step 5, when the 5G broadband wireless channel and the HPLC narrowband power line channel simultaneously detect a signal-to-noise ratio recovery gap that meets the duration requirement, a minimized transmission unit is simultaneously injected into the 5G broadband wireless channel and the HPLC narrowband power line channel to perform parallel micro-burst transmission. The first channel to receive a transmission confirmation response is marked as a successful delivery.

[0084] Step 6: Detect channel recovery and resume transmission of multi-service data;

[0085] Continuously monitor the signal-to-noise ratio (SNR) values ​​of channels under interference suppression. When the SNR value of any channel recovers to the minimum transmission SNR threshold... When the above conditions are met and the preset stability determination time is reached, the interference suppression state of the channel is lifted and the channel is marked as available.

[0086] According to the timestamp priority order, ordinary service data frames in the preventive buffer are sequentially scheduled to the recovery channel for transmission. For ordinary service data frames that were previously suspended by preemptive scheduling in step 2, transmission is resumed on the recovery channel from the transmission breakpoint position based on the recorded transmission breakpoint location and transmission context information, completing the transmission of the remaining part of the ordinary service data frame.

[0087] Furthermore, the aforementioned timestamp priority order refers to arranging ordinary service data frames in the order of their timestamps entering the preventive buffer from earliest to latest, with ordinary service data frames with earlier timestamps being scheduled first.

[0088] Furthermore, the aforementioned stability determination time refers to the shortest time that the channel signal-to-noise ratio needs to be maintained after it recovers to above the minimum transmission signal-to-noise ratio threshold, in order to avoid misjudging that the channel has been restored to usability due to the intermittent rise of transient electromagnetic pulses.

[0089] Furthermore, the aforementioned resume transmission refers to the process of continuing the transmission of the remaining portion of a normal service data frame from the point of interruption in the preemptive scheduling. Specifically, the power grid communication access terminal reads the byte offset, modulation and coding scheme, channel coding parameters, and target receiving address of the normal service data frame from the interruption record table, configures the physical layer's modulation encoder and channel encoder to the recorded parameter values, and then reads the remaining data after the byte offset from the multi-service data frame storage area and submits it to the physical layer for transmission. The physical layer encodes and modulates the remaining data according to the configured parameters and sends it to the target receiving address. The target receiving end concatenates the resumed data with the previously received portion to complete the reassembly of the complete multi-service data frame.

[0090] Furthermore, in order to make full use of channel bandwidth resources when multiple channels are restored to availability one after another, after both the 5G broadband wireless channel and the HPLC narrowband power line channel are restored to availability, dual-channel load balancing scheduling is performed on the remaining ordinary service data frames in the preventive buffer. Based on the current transmission rate and queuing depth of the 5G broadband wireless channel and the HPLC narrowband power line channel, the ordinary service data frames are allocated to the channel with lower load for transmission.

[0091] In one embodiment of the present invention, a broadband and narrowband converged power grid multi-service reliable communication access system is proposed, comprising:

[0092] The emergency flag identification module is used to perform a fast scan of the frame header of the multi-service data frames arriving at the power grid communication access terminal, extract the frame type field and compare it with the pre-stored real-time control and protection service feature code to output the emergency flag bit. When the emergency flag bit is set, the multi-service data frame is injected into the low-latency transmission buffer.

[0093] The dual-channel scheduling module is used to read the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel, obtain the signal-to-noise ratio index value and determine whether there is an available channel. When there is an available channel, the channel with the best transmission delay index is selected to perform preemptive scheduling on the emergency data frame and send it immediately.

[0094] The interference monitoring module is used to continuously monitor the real-time signal-to-noise ratio (SNR) of the two channels. When the absolute value of the SNR change of any channel exceeds the threshold of sharp drop and the SNR value drops below the minimum transmission SNR threshold, the channel is marked to enter the interference suppression state.

[0095] The high-frequency detection module is used to start the high-frequency signal-to-noise ratio detection mode when both channels are in the interference suppression state and there are urgent data frames to be sent in the low-latency transmission buffer. It performs instantaneous signal-to-noise ratio sampling in parallel at microsecond-level sampling intervals, identifies the signal-to-noise ratio recovery gap, and calculates its duration.

[0096] The micro-burst transmission module is used to perform minimal preprocessing on emergency data frames to generate minimal transmission units. When the duration of the signal-to-noise ratio recovery gap is detected to meet the minimum transmission duration required for the minimal transmission unit, the minimal transmission unit is injected into the corresponding channel to perform micro-burst transmission.

[0097] The channel recovery module is used to release the interference suppression state when the signal-to-noise ratio index value of the channel in the interference suppression state is restored to above the minimum transmission signal-to-noise ratio threshold and continues to be stable for a certain period of time. It then resumes the transmission of suspended ordinary service data frames based on the transmission breakpoint location and transmission context information.

[0098] This embodiment provides a layered processing method for reliable multi-service communication access to the power grid, addressing the extreme combined operating conditions where 5G broadband wireless channels and HPLC narrowband power line channels are simultaneously subjected to transient electromagnetic pulse interference.

[0099] First, because the method of fast frame header scanning and emergency flag identification is adopted in step 1, the frame type field at a fixed offset position in the frame header of the multi-service data frame arriving at the power grid communication access terminal is read only to compare the feature code of real-time control protection services. When real-time protection services are identified, they are directly injected into the low-latency transmission buffer and the regular service classification and channel optimization routing process is skipped. Therefore, the processing delay introduced by the regular service classification and channel optimization routing process is eliminated, and the time from when the emergency data frame arrives at the power grid communication access terminal to when it enters the schedulable state is compressed from tens of milliseconds to microseconds.

[0100] Secondly, because in step 3, an interference event prediction time window is generated by receiving the power grid primary equipment operation forecast information, and a preventive buffering operation is performed to suspend the scheduling of ordinary service data frames before the interference event prediction time window arrives, ordinary service data frames are prevented from being scheduled to the channel for invalid transmission during interference, thus reducing the invalid occupation of channel resources during interference.

[0101] Furthermore, in steps 4 and 5, when both the 5G broadband wireless channel and the HPLC narrowband power line channel are in an interference suppression state, a high-frequency signal-to-noise ratio (SNR) detection mode with a microsecond-level sampling interval is used to identify the brief SNR recovery gap between transient electromagnetic pulses. The emergency data frame is preprocessed into a minimized transmission unit that retains only the instruction opcode, target device address, and cyclic redundancy check code to compress the required transmission time. Micro-burst transmission is performed using the SNR recovery gap. Therefore, the transmission deadlock of emergency instructions having no channel to choose from when both the 5G broadband wireless channel and the HPLC narrowband power line channel are simultaneously unavailable is overcome, ensuring that emergency protection instructions still have a transmission path even when the 5G broadband wireless channel and the HPLC narrowband power line channel are continuously disturbed.

[0102] Because of the synergistic effect of the above steps, this implementation eliminates the delay in the routine service classification and channel optimization routing process during the emergency flag identification phase; ensures the priority transmission of emergency data frames through preemptive scheduling during the channel availability phase; maintains the reachability of emergency commands through signal-to-noise ratio recovery gap detection and minimizing micro-burst transmission of transmission units during the simultaneous interference phase of the 5G broadband wireless channel and the HPLC narrowband power line channel; and restores the complete access of ordinary service data through transmission breakpoint location continuation and timestamp priority scheduling during the channel recovery phase. Therefore, it solves the problem of reliable communication guarantee under the extreme working conditions of simultaneous interference of the 5G broadband wireless channel and the HPLC narrowband power line channel and the superposition of real-time protection ultra-low latency requirements.

[0103] like Figures 2-9 As shown, the above-mentioned broadband and narrowband converged power grid multi-service reliable communication access method and system are applied to the following application scenarios in specific examples:

[0104] A planned busbar switching operation is required for the 10kV distribution lines under the jurisdiction of substation A in a certain city's power distribution network. These distribution lines are connected to over 200 distribution terminals, which communicate with the main station system via 5G broadband wireless channels and HPLC narrowband power line channels.

[0105] At 10:30 on March 15, 20XX, the dispatch system issued a bus switching operation notice, which was scheduled to be carried out at 10:35 on the opening of the 500kV bus circuit breaker.

[0106] The DTU-A07 distribution terminal on this line is located in a distribution room 2.3 kilometers away from the operating equipment. The terminal is processing three types of business data: periodically reported power metering data, real-time monitored line voltage and current data, and an emergency trip control command that has just arrived (to isolate the downstream fault point).

[0107] Busbar switching operations will generate a transient electromagnetic pulse lasting approximately 150 milliseconds. This pulse will simultaneously interfere with 5G wireless signals and power line carrier signals, causing both channels of the distribution terminal DTU-A07 to become unavailable for a short period of time.

[0108] Step 1: Identify emergency trip commands and inject a fast bypass;

[0109] On March 15, 20XX, at 10:34:58.126, the power distribution terminal DTU-A07 received three data frames. The frame header fast scanning circuit sequentially extracted the frame type field of each frame and compared it with the pre-stored set of real-time control and protection business feature codes.

[0110] Table 1. Information on multi-service data frames arriving at the power distribution terminal

[0111] When the frame header fast scanning circuit detects that the frame type field value 0x1FA3 of Frame-202 matches the "emergency trip control instruction feature code" in the real-time control and protection service feature code set, it immediately generates a hardware interrupt signal. The processor responds to the interrupt within 1.8 microseconds after 10:34:58.127, directly writing the storage pointer 0x8A4C2000 of Frame-202 into the tail register of the low-latency transmission buffer, skipping the regular service classification and channel optimization routing process. Frames-201 and Frame-203, because their emergency flag bit is not set, are sent to the regular service classification module for further processing.

[0112] Table 2 Low-latency transmission buffer status

[0113] Through the fast bypass mechanism, the total delay from the arrival of Frame-202 to the entry into the dispatchable state is 1.8 microseconds, while Frame-201 and Frame-203 need to go through the regular service classification and channel optimization routing process, which introduces a processing delay of about 25 milliseconds.

[0114] Step 2: Query the availability of dual channels and prioritize scheduling urgent data frames;

[0115] At 10:34:58.129, the power distribution terminal DTU-A07 reads the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel to obtain the current signal-to-noise ratio index value.

[0116] Table 3 Dual-channel real-time availability status

[0117] Both channels met the usability requirements (signal-to-noise ratio not lower than the minimum transmission signal-to-noise ratio threshold). After comparing the transmission delay, the 5G broadband wireless channel (8.2ms) had a better transmission delay than the HPLC narrowband power line channel (12.5ms), therefore the 5G broadband wireless channel was selected as the target channel.

[0118] At 10:34:58.130, the power distribution terminal performs preemptive scheduling on Frame-202 in the low-latency transmission buffer. At this time, the 5G broadband wireless channel is transmitting ordinary service data frame Frame-198 (electricity metering data), which has been sent up to byte 96 (total length 128 bytes). The scheduling module sends a transmission pause command to the 5G physical layer. After completing the current physical layer frame, the physical layer stops transmitting and returns the offset of byte sent: 96.

[0119] Table 4 Breakpoint Records of Preempted Ordinary Service Data Frames

[0120] The power distribution terminal then injected Frame-202 into the 5G broadband wireless channel. The physical layer reconfigured the modulation encoder according to the transmission parameters of the emergency data frame (256QAM coding rate 5 / 6), and started sending Frame-202 at 10:34:58.132 and completed the transmission at 10:34:58.137, with a total time of 5 milliseconds.

[0121] Step 3: Monitor the dual-channel interference status and mark the interference suppression.

[0122] At 10:34:50, the distribution terminal DTU-A07 received the bus switching operation warning information issued by the dispatch system and obtained the following parameters.

[0123] Table 5. Grid Primary Equipment Operation Forecast Information

[0124] The distribution terminal, based on the operation type "500kV busbar circuit breaker tripping," retrieves a typical electromagnetic pulse duration of 150 milliseconds from a table. The electromagnetic wave propagation delay is calculated based on an electrical distance of 2.3 kilometers.

[0125]

[0126] Generate a time window for predicting interference events:

[0127] Expected start time of interference:

[0128] Expected end time of interference:

[0129] Table 6 Interference Event Prediction Time Window Parameters

[0130] The power distribution terminal is set with a preset lead time of 10 seconds. At 10:34:50.012 (i.e., 10 seconds before the expected start time of interference), a preventive buffering operation is performed on the ordinary service data frames to be sent in the transmission queue. Seven ordinary service data frames to be sent are moved from the transmission queue into the preventive buffer area, and the scheduling of new ordinary service data frames to the dual channels is suspended.

[0131] The power distribution terminal continuously monitors the real-time signal-to-noise ratio (SNR) of the dual channels, with a sampling period of 10 milliseconds. At 10:35:00.015, the transient electromagnetic pulse actually arrived, and the SNR of the 5G broadband wireless channel plummeted from 18.2dB to 6.8dB, while the SNR of the HPLC narrowband power line channel plummeted from 14.1dB to 5.3dB.

[0132] Table 7. Changes in signal-to-noise ratio before and after dual-channel interference

[0133] The power distribution terminal sets a sharp drop threshold of 5.0 dB. For the 5G broadband wireless channel, the absolute value of the signal-to-noise ratio (SNR) change is 11.4 dB, which is greater than the sharp drop threshold, and the current SNR of 6.8 dB is lower than the minimum transmission SNR threshold of 12.0 dB, marking the 5G broadband wireless channel as entering interference suppression mode. For the HPLC narrowband power line channel, the absolute value of the SNR change is 8.8 dB, which is greater than the sharp drop threshold, and the current SNR of 5.3 dB is lower than the minimum transmission SNR threshold of 12.0 dB, marking the HPLC narrowband power line channel as entering interference suppression mode. The power distribution terminal blocks the transmission of new multi-service data frames to both channels.

[0134] Step 4 achieves: detecting the high-frequency signal-to-noise ratio gap under dual-channel interference conditions;

[0135] At 10:35:00.020, the power distribution terminal detected that both channels were in interference suppression mode and that there was another emergency data frame Frame-205 to be sent in the low-latency transmission buffer (this frame arrived at 10:35:00.018, and the instruction content was a fault isolation instruction), and started the high-frequency signal-to-noise ratio detection mode.

[0136] The power distribution terminal increases the signal-to-noise ratio (SNR) sampling interval from the conventional 10 milliseconds to 50 microseconds, performs instantaneous SNR sampling on both channels in parallel, and obtains the instantaneous SNR time series.

[0137] Table 8 Instantaneous signal-to-noise ratio time series under high-frequency signal-to-noise ratio detection mode (partial sampling points)

[0138] The hardware comparator circuit of the power distribution terminal compares the sampled signal-to-noise ratio (SNR) value with the minimum transmission SNR threshold of 12.0 dB in real time. On the 5G broadband wireless channel, the SNR was detected to rise from 11.6 dB to 13.8 dB (rising edge time 10:35:00.020200), and thereafter, multiple consecutive sampled values ​​were higher than 12.0 dB, with the marking interval starting at 10:35:00.020200. When the SNR dropped from 12.1 dB to 9.8 dB (falling edge time 10:35:00.020450), the marking interval ended at 10:35:00.020450.

[0139] Calculate the duration of the signal-to-noise ratio recovery gap in a 5G broadband wireless channel:

[0140] For the HPLC narrow-band electric line channel, the signal-to-noise ratio was detected to rise from 7.5 dB to 12.4 dB (rise edge time 10:35:00.020200), the gap end time was 10:35:00.020400, and the duration was 0.200 ms.

[0141] Table 9. Detected signal-to-noise ratio recovery gap information

[0142] Step 5: Preprocess urgent data frames into minimized units and perform micro-burst transmission during interference gaps;

[0143] The power distribution terminal performs minimal preprocessing on Frame-205 in the low-latency transmission buffer, stripping away unnecessary protocol overhead fields and retaining only the instruction opcode, target device address, and cyclic redundancy check code.

[0144] Table 10 Comparison of Emergency Data Frame Minimization Preprocessing Before and After

[0145] The minimum data length of the transmission unit is 12 bytes. The physical layer transmission rate of the 5G broadband wireless channel is 25.5 Mbps. Calculate the shortest transmission time required to minimize the transmission unit:

[0146]

[0147] For the 5G broadband wireless channel, the detected gap duration of 0.250 milliseconds is greater than the minimum transmission duration of 0.004 milliseconds, thus meeting the transmission conditions. Within the minimum preparation time (2 microseconds) after the gap start time of 10:35:00.020200, the power distribution terminal submits the minimized transmission unit to the physical layer of the 5G broadband wireless channel. The physical layer adopts 256QAM modulation and a channel coding scheme with a coding rate of 5 / 6. Transmission begins at 10:35:00.020202 and is completed at 10:35:00.020206, actually occupying a transmission duration of 0.004 milliseconds.

[0148] The power distribution terminal sets a timeout window of 0.150 milliseconds and listens for transmission confirmation responses on the 5G broadband wireless channel. At 10:35:00.020318, it receives an confirmation response from the target device's power distribution switch SW-D23, marking Frame-205 as successfully delivered and removing Frame-205 from the low-latency transmission buffer.

[0149] Table 11 Key Time Points in the Microburst Transmission Process

[0150] By completing the micro-burst transmission of emergency data frames within a brief signal-to-noise ratio recovery interval of 0.250 milliseconds, the power distribution terminal successfully delivered the fault isolation command even under extreme conditions where both channels were in interference suppression mode, thus avoiding transmission deadlock.

[0151] Step 6 achieves: Detection channel recovery and resume transmission of multi-service data;

[0152] The power distribution terminal continuously monitored the signal-to-noise ratio (SNR) of the dual channels under interference suppression. At 10:35:00.165, the transient electromagnetic pulse interference had largely subsided, and the SNR of the 5G broadband wireless channel recovered to 13.2 dB, while the SNR of the HPLC narrowband power line channel recovered to 12.8 dB, both exceeding the minimum transmission SNR threshold of 12.0 dB.

[0153] The power distribution terminal is set to a stability determination time of 30 milliseconds. At 10:35:00.195, it is confirmed that the signal-to-noise ratio of the 5G broadband wireless channel remains above 12.0 dB for 30 milliseconds, thus removing the interference suppression state of the 5G broadband wireless channel and marking it as available. At 10:35:00.198, it is confirmed that the HPLC narrowband power line channel also meets the stability determination conditions, thus removing the interference suppression state of the HPLC narrowband power line channel.

[0154] Table 12 Signal-to-noise ratio monitoring during dual-channel recovery process

[0155] The power distribution terminal schedules the seven ordinary service data frames in the preventive buffer to the restored dual channels for transmission in sequence according to the timestamp priority order.

[0156] Table 13. Scheduling order of ordinary service data frames in the preventative buffer.

[0157] For the ordinary service data frame Frame-198, which was suspended by preemptive scheduling in step 2, the distribution terminal reads the transmission breakpoint location (byte offset 96) and transmission context information (modulation and coding scheme 64QAM coding rate 3 / 4, channel coding parameter Turbo code interleaving depth 512, target receive address 0x0001) from the breakpoint record table. At 10:35:00.202, it configures the physical layer of the 5G broadband wireless channel to the recorded parameter values, reads the remaining 32 bytes of data after byte offset 96 of Frame-198 from the multi-service data frame storage area, and submits them to the physical layer for transmission. After the physical layer completes the encoding and modulation of the remaining data at 10:35:00.205, it sends it to the master station system. The master station system concatenates the received 32 bytes of data with the previously received 96 bytes of data to complete the reassembly of Frame-198.

[0158] By employing dual-channel recovery detection, timestamp priority scheduling of preventative buffer data, and retransmission of interrupted ordinary service data frames, the power distribution terminal quickly restored its normal multi-service data access capability after the interference subsided.

[0159] In this application scenario, the transformation process of data from its initial state through each step embodies the complete data flow logic:

[0160] First, the emergency trip control command Frame-202, which arrived at 10:34:58.127, quickly scanned the emergency flag bit in the frame header and injected it into the low-latency transmission buffer within 1.8 microseconds (step 1).

[0161] Then at 10:34:58.130, by querying the availability of dual channels, the 5G broadband wireless channel was selected as the target channel. The preemptive scheduling paused the transmission of the ordinary service data frame Frame-198 and recorded the breakpoint position of 96 bytes. Frame-202 was sent first (step 2).

[0162] After the transient electromagnetic pulse arrives at 10:35:00.015, the dual-channel signal-to-noise ratio drops sharply and is marked as interference suppression state. The interference event prediction time window previously generated by the power grid primary equipment operation warning information triggers a preventive buffer operation, moving 7 ordinary service data frames to be sent into the preventive buffer area (step 3).

[0163] When both channels are unavailable at 10:35:00.020, the power distribution terminal starts the high-frequency signal-to-noise ratio detection mode and detects a 0.250-millisecond signal-to-noise ratio recovery gap in the 5G broadband wireless channel between 10:35:00.020200 and 10:35:00.020450 at a sampling interval of 50 microseconds (step 4).

[0164] Then, the emergency data frame Frame-205 to be sent is subjected to minimal preprocessing, which compresses 64 bytes into a minimum transmission unit of 12 bytes. Micro-burst transmission is performed within the detected signal-to-noise ratio recovery gap, and the transmission is completed within 0.004 milliseconds. An acknowledgment response is received after 0.118 milliseconds (step 5).

[0165] Finally, after the dual channels were restored to availability at 10:35:00.195 and 10:35:00.198, the seven ordinary service data frames in the preventive buffer were scheduled to the recovery channel in order of timestamp priority. The preempted Frame-198 was resumed from the breakpoint at byte 96 to complete the transmission of the remaining 32 bytes (step 6).

[0166] Throughout the process, emergency data frames achieved ultra-low latency transmission with an end-to-end latency of less than 20 milliseconds through fast bypass, preemptive scheduling, and micro-burst transmission during signal-to-noise ratio recovery intervals. Ordinary service data frames ensured complete data access through preventive buffering and transmission breakpoint continuation, demonstrating reliable communication guarantee capabilities under extreme conditions where both 5G broadband wireless channels and HPLC narrowband power line channels are simultaneously disturbed.

[0167] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for reliable multi-service communication access in a power grid that integrates broadband and narrowband bandwidth, characterized in that, Includes the following steps: Perform a fast scan of the frame header for the multi-service data frames arriving at the power grid communication access terminal, extract the frame type field and compare it with the pre-stored real-time control and protection service feature code, and output the emergency flag bit; When the emergency flag is set, the multi-service data frame is injected into the low-latency transmission buffer, skipping the regular service classification and channel optimization routing process; The system reads the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel, obtains the signal-to-noise ratio index value, and determines whether there is an available channel. When there is an available channel, the channel with the best transmission delay index is selected as the target channel, and preemptive scheduling is performed on the urgent data frames in the low-latency transmission buffer and they are sent immediately. Continuously monitor the real-time signal-to-noise ratio (SNR) of the two channels. When the absolute value of the SNR change of either channel exceeds the threshold for a sharp drop and the SNR value drops below the minimum transmission SNR threshold, the channel is marked as entering the interference suppression state. When both channels are in interference suppression mode and there are urgent data frames to be sent in the low-latency transmission buffer, the high-frequency signal-to-noise ratio detection mode is activated, and instantaneous signal-to-noise ratio sampling is performed in parallel at microsecond-level sampling intervals to identify the signal-to-noise ratio recovery gap and calculate its duration. For urgent data frames, perform minimal preprocessing, remove unnecessary protocol overhead fields, retain the instruction opcode, target device address and cyclic redundancy check code, and generate a minimal transmission unit; when the duration of the signal-to-noise ratio recovery gap is detected to meet the minimum transmission duration required by the minimal transmission unit, inject the minimal transmission unit into the corresponding channel to perform micro-burst transmission; When the signal-to-noise ratio (SNR) of a channel in the interference suppression state recovers to above the minimum transmission SNR threshold and remains stable for a certain period of time, the interference suppression state is lifted, and the suspended ordinary service data frames are resumed based on the transmission breakpoint location and transmission context information.

2. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, The processing when the emergency flag is set is performed using an interrupt-driven fast channel bypass method; when the frame header fast scanning circuit detects that the frame type field matches the feature code of the real-time control protection service, it generates a hardware interrupt signal. After the processor of the power grid communication access terminal responds to the hardware interrupt signal, it directly writes the storage pointer of the current multi-service data frame into the tail register of the low-latency transmission buffer, skipping the calls to the regular service classification module and the channel optimization routing module.

3. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, The preemptive scheduling includes: sending a transmission pause command to the physical layer of the target channel; the physical layer stops transmitting after completing the currently transmitting physical layer frame and returns the byte offset of the transmitted data to the scheduling module; the scheduling module stores the byte offset along with the modulation and coding scheme, channel coding parameters, and target receiving address in the breakpoint record table; then, it submits the transmission request of the emergency data frame to the physical layer; the physical layer reconfigures the modulation encoder and channel encoder according to the transmission parameters of the emergency data frame and then starts transmitting the emergency data frame.

4. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, The real-time signal-to-noise ratio index of the continuous monitoring dual channels also includes: receiving operation forecast information and fault warning signals from primary power grid equipment, and parsing the operation type, equipment location, and expected execution time contained therein; obtaining the corresponding typical electromagnetic pulse duration by looking up a table according to the operation type, and calculating the electromagnetic wave propagation delay based on the electrical distance between the equipment location and the power grid communication access terminal; adding the electromagnetic wave propagation delay to the expected execution time as the expected interference start time, and adding the typical electromagnetic pulse duration to the expected interference start time as the expected interference end time, thereby generating an interference event prediction time window.

5. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 4, characterized in that, At a preset lead time before the predicted time window of the interference event arrives, a preventive buffering operation is performed on the ordinary service data frames to be sent in the transmission queue. The ordinary service data frames to be sent are moved from the transmission queue into the preventive buffer area, and the scheduling of new ordinary service data frames to the 5G broadband wireless channel and the HPLC narrowband power line channel is suspended.

6. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, The identification of the signal-to-noise ratio (SNR) rise gap includes: in the instantaneous SNR time series, detecting the rising edge of the SNR value from below the minimum transmission SNR threshold to above or equal to the minimum transmission SNR threshold as the gap start point, and detecting the falling edge of the SNR value from above or equal to the minimum transmission SNR threshold to below the minimum transmission SNR threshold as the gap end point; the duration of the SNR rise gap is the time difference between the gap end time and the gap start time.

7. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, The micro-burst transmission is followed by: parallel monitoring of transmission confirmation responses on the 5G broadband wireless channel and the HPLC narrowband power line channel; if a transmission confirmation response is received within the set timeout window, the emergency data frame is marked as successfully delivered and removed from the low-latency transmission buffer; if no transmission confirmation response is received within the set timeout window, the minimized transmission unit is marked as pending retransmission, and retransmission is performed in the next signal-to-noise ratio recovery gap that meets the duration requirement; when the cumulative retransmission count of the same minimized transmission unit reaches the upper limit of the cumulative retransmission count, the retransmission operation is stopped and a delivery failure alarm message is output to the upper-level management system.

8. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 1, characterized in that, When the 5G broadband wireless channel and the HPLC narrowband power line channel simultaneously detect the signal-to-noise ratio recovery gap that meets the duration requirement, a minimized transmission unit is injected into the 5G broadband wireless channel and the HPLC narrowband power line channel to perform parallel micro-burst transmission. The first channel to receive the transmission confirmation response marks the delivery as successful.

9. The broadband and narrowband converged power grid multi-service reliable communication access method according to claim 5, characterized in that, After the interference suppression state is lifted, the process further includes: scheduling ordinary service data frames in the preventive buffer to the recovery channel for transmission in order of their timestamps from earliest to latest; after both the 5G broadband wireless channel and the HPLC narrowband power line channel are restored to available status, performing dual-channel load balancing scheduling on the remaining ordinary service data frames in the preventive buffer, and allocating the ordinary service data frames to the channels with low load for transmission based on the current transmission rate and queuing depth of each channel.

10. A broadband and narrowband converged power grid multi-service reliable communication access system, used to execute the broadband and narrowband converged power grid multi-service reliable communication access method according to any one of claims 1 to 9, characterized in that, include: The emergency flag identification module is used to perform a fast scan of the frame header of the multi-service data frames arriving at the power grid communication access terminal, extract the frame type field and compare it with the pre-stored real-time control and protection service feature code, output the emergency flag bit, and inject the multi-service data frame into the low-latency transmission buffer when the emergency flag bit is set. The dual-channel scheduling module is used to read the real-time availability status registers of the 5G broadband wireless channel and the HPLC narrowband power line channel in parallel, obtain the signal-to-noise ratio index value and determine whether there is an available channel. When there is an available channel, the channel with the best transmission delay index is selected to perform preemptive scheduling on the emergency data frame and send it immediately. The interference monitoring module is used to continuously monitor the real-time signal-to-noise ratio (SNR) of the two channels. When the absolute value of the SNR change of any channel exceeds the threshold of sharp drop and the SNR value drops below the minimum transmission SNR threshold, the channel is marked to enter the interference suppression state. The high-frequency detection module is used to start the high-frequency signal-to-noise ratio detection mode when both channels are in the interference suppression state and there are urgent data frames to be sent in the low-latency transmission buffer. It performs instantaneous signal-to-noise ratio sampling in parallel at microsecond-level sampling intervals, identifies the signal-to-noise ratio recovery gap, and calculates its duration. The micro-burst transmission module is used to perform minimal preprocessing on emergency data frames to generate minimal transmission units. When the duration of the signal-to-noise ratio recovery gap is detected to meet the minimum transmission duration required for the minimal transmission unit, the minimal transmission unit is injected into the corresponding channel to perform micro-burst transmission. The channel recovery module is used to release the interference suppression state when the signal-to-noise ratio index value of the channel in the interference suppression state is restored to above the minimum transmission signal-to-noise ratio threshold and continues to be stable for a certain period of time. It then resumes the transmission of suspended ordinary service data frames based on the transmission breakpoint location and transmission context information.

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