Power measurement communication method and system based on lightweight Beidou protocol and data compression

Abstract

The invention relates to the technical field of communication engineering and intelligent power grids, in particular to an electric power measurement communication method and system based on a lightweight Beidou protocol and data compression, and aims to solve the problems of low channel utilization rate, long transmission delay and the like caused by the fact that an existing Beidou RDSS protocol is high in redundancy and not adaptive to electric power measurement data characteristics. According to the method, a light-weight Beidou protocol oriented to an electric power measurement service and an improved LZ77 compression algorithm are fused, differential preprocessing and field isolation matching compression are carried out on structured time sequence measurement data, and packaging transmission is carried out by adopting a cut minimum frame structure. Through the technology, the short message information bearing efficiency is remarkably improved, the transmission overhead is reduced, and the end-to-end communication cost is greatly reduced while the data integrity and timeliness are guaranteed.

Description

Technical Field

[0001] This invention relates to the fields of communication engineering and smart grid technology, and in particular to a power metering communication method and system based on lightweight BeiDou protocol and data compression. Background Technology

[0002] In power systems, power metering communication is crucial for ensuring stable grid operation, accurate energy metering, and efficient electricity billing. With the deepening of smart grid construction, the amount of data generated by power metering terminals is growing exponentially, placing higher demands on the bandwidth, latency, reliability, and coverage of communication systems. Especially in remote mountainous areas, oceans, deserts, and other regions where public network signals are difficult to access, traditional 4G / 5G and other terrestrial communication methods have blind spots, resulting in incomplete data collection or severe delays. BeiDou satellite communication, with its advantages of wide-area coverage, high reliability, and independent controllability, has become an important means to solve the power metering communication problem in areas without public networks. However, existing BeiDou-based power communication solutions mostly directly adopt the standard RDSS protocol without tailoring the protocol to the characteristics of power metering services, resulting in high communication overhead and low transmission efficiency. Simultaneously, the lack of a coordinated and efficient data compression mechanism makes it difficult to meet the requirements of high-frequency, high-precision, and low-latency transmission of power metering data.

[0003] A search revealed a patent, CN108898814B, concerning a method and system for acquiring and transmitting power data. This patent proposes establishing a TCP connection between the power metering terminal and the RDSS BeiDou communication module, and then uploading the processed power data via the BeiDou link to reduce backend communication pressure and lower deployment costs. However, this solution still uses the standard BeiDou RDSS communication protocol without any trimming or optimization of the protocol stack, resulting in redundant signaling interactions and low efficiency in single-communication transmission. Furthermore, it lacks a targeted data compression mechanism, meaning that raw power data (such as voltage, current, and power time-series data) is uploaded uncompressed. Under the limited bandwidth of BeiDou short messages (typically ≤1000 bits / message), it is difficult to support high-frequency, multi-parameter metering data backhaul, limiting its application in scenarios with high real-time requirements.

[0004] A search revealed a communication method and system for power protection metering chips, published under publication number CN119094089B. This patent assesses data redundancy by analyzing environmental interference levels and dynamically selects the communication transmission method accordingly to improve transmission efficiency. While this solution addresses data redundancy, its core lies in the selection of transmission strategies (such as whether to retransmit or reduce the frequency), without involving compression encoding of the original metering data itself or end-to-end collaborative optimization using specific communication protocols (such as BeiDou). Furthermore, this method relies on historical data and environmental characteristics such as temperature for redundancy assessment, resulting in high computational complexity and making it difficult to implement efficiently on resource-constrained metering terminals. It also fails to address the bandwidth bottleneck issue under narrowband satellite channels.

[0005] The aforementioned problems indicate that existing technologies, when applying BeiDou communication to power metering scenarios, generally suffer from shortcomings such as insufficient protocol lightweighting, inefficient data compression, and low communication efficiency and bandwidth utilization. These deficiencies make it difficult to meet the practical needs of power metering systems in areas without public networks for high reliability, low latency, and high-frequency data backhaul. Therefore, this invention proposes a power metering communication method and system based on a lightweight BeiDou protocol and data compression. The aim is to significantly improve data transmission efficiency and system responsiveness under satellite channels by customizing and simplifying the BeiDou communication protocol and integrating a highly efficient compression algorithm tailored to the characteristics of power metering data, thus providing reliable communication support for wide-area power metering. Summary of the Invention

[0006] This invention provides a power metering communication method and system based on a lightweight BeiDou protocol and data compression, aiming to solve the technical problems in existing technologies, such as low satellite channel resource utilization, large transmission delay, and poor system scalability caused by the high redundancy of the standard BeiDou RDSS protocol and its lack of adaptation to the characteristics of power metering data. To achieve the above-mentioned objectives, this invention deeply integrates a lightweight communication protocol design oriented towards the characteristics of power metering services with an efficient data compression mechanism, constructing an end-to-end collaboratively optimized data transmission architecture. While ensuring data integrity, accuracy, and timeliness, it significantly improves the information carrying efficiency of a single BeiDou short message, reduces end-to-end transmission overhead, and ensures engineering feasibility on resource-constrained embedded terminals.

[0007] The power metering communication method of this invention includes the following steps: A power metering terminal periodically collects multi-dimensional power parameters such as voltage, current, active power, reactive power, power factor, frequency, and cumulative energy value to form a structured time-series data sequence; the time-series data sequence is classified and organized according to physical quantity type and cached in a local non-volatile memory; the cached data is losslessly compressed using an improved LZ77 compression algorithm; the compressed data stream is encapsulated according to the lightweight BeiDou protocol frame structure defined in this invention to generate a bit stream that conforms to the modulation requirements of the BeiDou RDSS physical layer; the bit stream is modulated by a radio frequency front-end and transmitted to a BeiDou geostationary orbit (GEO) satellite via a BeiDou communication module; the BeiDou satellite receives and forwards the signal to a ground receiving station; after the ground receiving station completes signal demodulation, frame parsing, data decompression, and verification, it uploads the original metering data to the power metering master station via a dedicated power network or fiber optic link; the power metering master station performs in-depth analysis, long-term storage, statistical report generation, and visualization of the received data, and can issue remote configuration instructions or control commands to designated power metering terminals according to the operating strategy.

[0008] The power metering and communication system described in this invention consists of five parts: a power metering terminal, a BeiDou communication module, a BeiDou satellite, a ground receiving station, and a power metering master station. The power metering terminal is deployed on the user side or in a distribution substation, used for high-precision electrical parameter acquisition, local caching, and preprocessing. The BeiDou communication module is integrated inside the power metering terminal or externally connected via an RS-485 / UART interface, responsible for protocol encapsulation, data compression, and satellite link access. The BeiDou satellite serves as a space relay node, providing two-way short message communication services. The ground receiving station is located at a designated site of the State Grid or China Southern Power Grid, possessing BeiDou RDSS signal reception, decoding, and gateway forwarding functions. The power metering master station is located in a provincial or municipal dispatch center, undertaking tasks such as network-wide data aggregation, business logic processing, and human-machine interaction.

[0009] Furthermore, the power metering terminal includes a high-precision metering chip, a microcontroller unit (MCU), a real-time clock (RTC), non-volatile memory, and a communication interface circuit. The high-precision metering chip uses a three-phase multi-functional energy metering integrated circuit supporting the IEC 62053-22 standard. Its voltage channel sampling rate is 8kHz, the current channel dynamic range is no less than 5000:1, the effective number of bits (ENOB) is no less than 16 bits, and the output format is IEEE 754 single-precision floating-point number or 32-bit signed integer. The microcontroller unit uses an ARM Cortex-M4 core processor with a main frequency of no less than 120MHz, a built-in hardware floating-point unit (FPU) and a cyclic redundancy check (CRC) acceleration engine, and runs a real-time operating system (RTOS) with a task scheduling cycle of 1ms. The non-volatile memory is a serial flash memory with an SPI interface, with a capacity of no less than 8MB, used to cache raw metering data and compressed intermediate results from the most recent 24 hours. The communication interface circuit supports RS-485, UART and SPI buses. The UART interface is used to connect to the Beidou communication module. The baud rate is fixed at 9600bps, with 8 data bits, 1 stop bit and no parity.

[0010] In a preferred embodiment of the present invention, at the end of each sampling period, the power metering terminal arranges the physical quantity values ​​at the current moment into structured data blocks in a predefined order. Each data block contains a timestamp (4 bytes), effective voltage value (4 bytes × 3 phases), effective current value (4 bytes × 3 phases), active power (4 bytes), reactive power (4 bytes), apparent power (4 bytes), power factor (4 bytes), frequency (4 bytes), and cumulative forward / reverse active energy value (8 bytes × 2), totaling 68 bytes. The timestamp adopts the Unix timestamp format, in seconds, and all floating-point values ​​are encoded according to the IEEE 754 standard, while integer values ​​are stored in little-endian order. This structured data block is written to a circular buffer. When the buffer is filled to a preset threshold (e.g., 10 consecutive data blocks, totaling 680 bytes) or reaches the maximum waiting time (e.g., 60 seconds), the compression and upload process is triggered.

[0011] Furthermore, the improved LZ77 compression algorithm introduces three key technological optimizations based on the traditional sliding window matching mechanism: First, a fixed-length sliding window is used, with the window size set to 2048 bytes to match the memory constraints of the embedded terminal; Second, during the dictionary lookup stage, cross-sample matching is only performed on fields of consecutive identical physical quantities. That is, voltage sequences are only matched with historical voltage sequences, and current sequences are only matched with historical current sequences, thus avoiding invalid matching between different types of data and improving the compression ratio. Third, a differential preprocessing step is introduced. First-order differential operation is performed on the time series of each physical quantity, that is, the difference between the current sample value and the previous sample value is calculated, and then LZ77 compression is performed on the differential sequence. This differential operation significantly enhances data stability, making it particularly suitable for distribution scenarios with slow load changes. Specifically, let the original voltage sequence... Then the difference sequence is Because power system operation is highly continuous, The absolute values ​​of elements other than the first element are usually much smaller than the original value and many are close to zero, resulting in longer repetition patterns and higher compression efficiency in subsequent LZ77 encoding.

[0012] The improved LZ77 compression algorithm outputs a compressed data stream, formatted according to the standard LZ77 triplet notation: (offset, length, next character). The offset is represented by an 11-bit unsigned integer, ranging from 0 to 2047; the length is represented by a 4-bit unsigned integer, ranging from 3 to 18 (the minimum matching length is set to 3 bytes); the next character is 1 byte of raw data. When no match occurs, the raw byte is output directly, and the length field is marked as 0. The compression process is implemented by MCU software, using a DMA controller to move the data to be compressed from flash memory to the SRAM working area. The compression result is temporarily stored in another SRAM buffer and written back to flash memory after the complete compressed package is generated.

[0013] As one of the core innovations of this invention, the lightweight BeiDou protocol structurally trims and reconstructs the standard RDSS protocol stack, removing functional fields and signaling interactions unrelated to power metering services. The standard RDSS protocol frame contains a user ID (4 bytes), location information (8 bytes), time information (4 bytes), response flag (1 byte), data payload (≤950 bytes), and checksum (2 bytes), with a total overhead of up to 19 bytes. The lightweight protocol frame structure defined in this invention retains only necessary fields, specifically including: frame header (2 bytes), terminal identifier (4 bytes), data type identifier (1 byte), compressed data payload (variable length, maximum 980 bytes), and checksum (2 bytes). The frame header is fixed at 0x5AA5 for frame synchronization; the terminal identifier uses the State Grid unified coding rules and is a 32-bit unsigned integer, uniquely identifying each metering terminal; the data type identifier distinguishes between regular metering data, event alarm data, or acknowledgment data responding to master station commands, with a value of 0x01 indicating regular metering data; the checksum uses the 16-bit CRC-CCITT polynomial of the ITU-T G.704 standard. Calculated and generated, with an initial value of 0xFFFF.

[0014] Furthermore, the lightweight BeiDou protocol eliminates the location reporting and two-way acknowledgment mechanisms found in the standard RDSS. In power metering applications, the terminal's geographical location is fixed and known, eliminating the need for coordinate information in each transmission. Simultaneously, given that satellite links primarily rely on unidirectional transmission and incur high retransmission costs, this invention employs a Best-Effort transmission strategy. It indirectly determines transmission reliability by relying on frame integrity verification at the ground receiving station and data continuity detection at the master station, rather than introducing ACK / NACK interactions at the link layer. This reduces the single-frame protocol overhead from 19 bytes to 9 bytes, increasing the effective payload ratio from approximately 98% to 99.1%. Within the 980-byte maximum payload limit, it can accommodate approximately 9 more bytes of effective information. Combined with the aforementioned compression technology, the overall information density is increased by over 300%.

[0015] As another key feature of this invention, the BeiDou communication module employs a dedicated radio frequency chip conforming to the BeiDou-2 RDSS interface specification, and its baseband processor integrates a hardware acceleration engine for the lightweight protocol described in this invention. This engine implements the hardware logic for protocol encapsulation and decapsulation above the physical layer, including frame header insertion, CRC calculation, bit stuffing, and NRZI encoding. When the MCU sends a compressed data stream to the BeiDou communication module via the UART interface, the module automatically adds a terminal identifier and data type identifier, calculates the CRC checksum, and generates a complete lightweight protocol frame. Subsequently, this frame is modulated using GMSK (modulation index 0.5, symbol rate 16kbps) and then transmitted by an antenna driven by a power amplifier. The transmit power can be configured to 1W or 5W, corresponding to EIRPs of 36dBm or 43dBm respectively, meeting the link budget requirements under different terrain and obstruction conditions.

[0016] The ground receiving station includes a BeiDou RDSS receiving antenna, a low-noise amplifier (LNA), a downconverter, an ADC sampling unit, a baseband demodulator, and a network interface unit. The receiving antenna is a right-hand circularly polarized (RHCP) planar array with a gain ≥10dBi; the LNA noise figure is ≤1.5dB; the downconverter downconverts the L-band (1610–1626.5MHz) signal to a 70MHz intermediate frequency; the ADC sampling rate is 20MHz with a 12-bit resolution; the baseband demodulator performs GMSK coherent demodulation, frame synchronization, CRC check, and lightweight protocol parsing. If the CRC check fails, the frame is discarded; if the check passes, the compressed data payload is extracted and uploaded to the power metering master station via a gigabit Ethernet interface. The ground receiving station can process no less than 50 short messages per second, with an average processing latency of less than 10ms.

[0017] The power metering master station is deployed in the provincial data center, running a Linux operating system and equipped with a multi-core CPU and high-speed SSD storage array. After receiving data streams from multiple ground receiving stations, the master station first routes the data to the corresponding virtual channel based on the terminal identifier; then, it calls the LZ77 decompression algorithm, consistent with the terminal, to restore the original structured data blocks; next, it performs data integrity verification, including timestamp continuity checks, physical quantity rationality verification (e.g., voltage should be within ±10% of the rated value), and monotonicity judgment of accumulated energy value; the verified data is written to a time-series database (e.g., InfluxDB) and triggers upper-layer application modules to perform load forecasting, line loss analysis, or abnormal power consumption detection. The master station can also generate downlink control commands, such as adjusting the sampling period, enabling event-triggered reporting, or remote meter calibration commands. These commands are encrypted and encapsulated into lightweight protocol frames, which are sent to the target terminal via the uplink from the ground station. The downlink frame structure is consistent with the uplink frame, except that the data type identifier is set to 0x02, and the payload content is the binary encoding of the command.

[0018] In a preferred embodiment of the present invention, the improved LZ77 compression algorithm, when implemented on the MCU side, employs a dual-buffered pipeline architecture to improve throughput. Specifically, while the DMA is moving the Nth batch of raw data from flash memory into SRAM buffer A, the CPU performs the compression operation of the (N-1)th batch of data in parallel and writes the result to buffer B. After compression is complete, the contents of buffer B are moved back to flash memory by the DMA, and buffer A is switched to output buffer. This mechanism overlaps compression processing with data movement, effectively hiding I / O latency. Actual measurements show that at a 120MHz clock frequency, compressing 680 bytes of data takes approximately 18ms, far less than the maximum waiting window of 60 seconds, meeting real-time requirements.

[0019] Furthermore, to address the issue of drastic fluctuations in the differential sequence and decreased compression efficiency caused by extreme load mutations, this invention introduces an adaptive compression mode switching mechanism. Before each compression, the MCU calculates the Euclidean distance between the current data block and the previous data block. ,in These are the normalized values ​​of the i-th physical quantity in the two data blocks (the normalization factor is the nominal value of the physical quantity). If D > θ (the threshold θ is set to 0.3), it is determined to be a sudden change condition, and differential preprocessing is skipped, and LZ77 compression is directly performed on the original data; otherwise, differential mode is enabled. This mechanism ensures that a better compression ratio can be obtained under both steady-state and transient conditions.

[0020] At the protocol level, the lightweight frame structure defined in this invention supports multiple terminals reusing the same ground receiving station resources. Because the terminal identifier is globally unique, the ground station can unambiguously distinguish data from different sources. Furthermore, the data type identifier field reserves extension bits to support new service types in the future (e.g., 0x03 for harmonic data, 0x04 for power quality events), demonstrating good scalability. The checksum uses a 16-bit CRC instead of a more complex hash algorithm, balancing error detection capability with computational overhead, resulting in a lower false detection rate than... .

[0021] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: First, at the data source end, based on the highly structured and time-series stationarity of power metering data, an improved LZ77 algorithm with differential preprocessing and field isolation matching is designed to significantly reduce the volume of the original data. Second, at the protocol layer, redundant fields for location reporting and identity authentication that are irrelevant to metering services in the general RDSS protocol are completely eliminated, and the frame structure is reconstructed to minimize the effective payload ratio. Third, in terms of system architecture, compression and protocol encapsulation are deeply coupled to form an integrated processing pipeline of "acquisition-classification-differentiation-compression-lightweight encapsulation-satellite launch", eliminating the double overhead caused by the separation of protocol processing and data compression in traditional solutions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall architecture of the power metering and communication system of the present invention; Figure 2 This is a hardware block diagram of the power metering terminal described in this invention; Figure 3 This is a schematic diagram of the structured data block format in this invention; Figure 4 This is a flowchart of the improved LZ77 compression algorithm described in this invention. Figure 5 This is a schematic diagram of the lightweight BeiDou protocol frame structure defined in this invention; Figure 6 This is an end-to-end workflow diagram of the power metering communication method described in this invention. Detailed Implementation

[0023] This invention provides a power metering communication method and system based on a lightweight BeiDou protocol and data compression. The technical solution of this invention will be described in detail, completely, and practically, with reference to the accompanying drawings and specific embodiments, to ensure that those skilled in the art can reproduce all the technical effects of this invention based on this specification.

[0024] like Figure 1As shown, the power metering communication system of this invention consists of five parts: a power metering terminal, a Beidou communication module, a Beidou satellite, a ground receiving station, and a power metering master station. The power metering terminal is deployed on the user side or in a distribution substation, used for high-precision electrical parameter acquisition, local caching, and preprocessing. The Beidou communication module is integrated inside the power metering terminal or externally connected via an RS-485 / UART interface, responsible for protocol encapsulation, data compression, and satellite link access. The Beidou satellite serves as a space relay node, providing bidirectional short message communication services. The ground receiving station is located at a designated site of the State Grid or Southern Power Grid, possessing Beidou RDSS signal reception, decoding, and gateway forwarding functions. The power metering master station is located in a provincial or municipal dispatch center, undertaking tasks such as network-wide data aggregation, business logic processing, and human-machine interaction.

[0025] like Figure 2 As shown, the power metering terminal includes a high-precision metering chip, a microcontroller unit (MCU), a real-time clock (RTC), non-volatile memory, and communication interface circuitry. The high-precision metering chip uses a three-phase multi-functional energy metering integrated circuit supporting the IEC 62053-22 standard. Its voltage channel sampling rate is 8kHz, the current channel dynamic range is no less than 5000:1, the effective number of bits (ENOB) is no less than 16 bits, and the output format is IEEE 754 single-precision floating-point number or 32-bit signed integer. The microcontroller unit uses an ARM Cortex-M4 core processor with a main frequency of no less than 120MHz. It has a built-in hardware floating-point unit (FPU) and a cyclic redundancy check (CRC) acceleration engine, runs a real-time operating system (RTOS), and has a task scheduling cycle of 1ms. The non-volatile memory is a serial flash memory with an SPI interface, with a capacity of no less than 8MB, used to cache raw metering data and compressed intermediate results from the most recent 24 hours. The communication interface circuit supports RS-485, UART and SPI buses. The UART interface is used to connect to the Beidou communication module. The baud rate is fixed at 9600bps, with 8 data bits, 1 stop bit and no parity.

[0026] In one specific embodiment, at the end of each sampling period, the power metering terminal arranges the current physical quantity values ​​into structured data blocks according to a predefined order. For example... Figure 3As shown, each data block contains a timestamp (4 bytes), RMS voltage value (4 bytes × 3 phases), RMS current value (4 bytes × 3 phases), active power (4 bytes), reactive power (4 bytes), apparent power (4 bytes), power factor (4 bytes), frequency (4 bytes), and cumulative forward / reverse active energy value (8 bytes × 2), totaling 68 bytes. The timestamp uses the Unix timestamp format, in seconds, and all floating-point values ​​are encoded according to the IEEE 754 standard. Integer values ​​are stored in little-endian order. This structured data block is written to a circular buffer. When the buffer fills to a preset threshold (e.g., 10 consecutive data blocks, totaling 680 bytes) or reaches the maximum waiting time (e.g., 60 seconds), the compression and upload process is triggered.

[0027] Furthermore, the compression process employs an improved LZ77 compression algorithm. For example... Figure 4 As shown, this algorithm introduces three key technological optimizations based on the traditional sliding window matching mechanism. First, a fixed-length sliding window is used, with a window size set to 2048 bytes to match the memory constraints of embedded terminals. Second, in the dictionary lookup stage, cross-sample matching is only performed on consecutive identical physical quantity fields; that is, voltage sequences are only matched with historical voltage sequences, and current sequences are only matched with historical current sequences, avoiding invalid matches between different types of data and improving the compression ratio. Third, a differential preprocessing step is introduced, performing a first-order difference operation on the time series of each physical quantity, i.e., calculating the difference between the current sample value and the previous sample value, and then performing LZ77 compression on the difference sequence. Specifically, let the original voltage sequence... Then the difference sequence is Because power system operation is highly continuous, The absolute values ​​of elements other than the first element are usually much smaller than the original value and many are close to zero, resulting in longer repetition patterns and higher compression efficiency in subsequent LZ77 encoding.

[0028] In a preferred embodiment of the present invention, the improved LZ77 compression algorithm, when implemented on the MCU side, employs a dual-buffered pipeline architecture to improve throughput. Specifically, while the DMA is moving the Nth batch of raw data from flash memory into SRAM buffer A, the CPU performs the compression operation of the (N-1)th batch of data in parallel and writes the result to buffer B. After compression is complete, the contents of buffer B are moved back to flash memory by the DMA, and buffer A is switched to output buffer. This mechanism overlaps compression processing with data movement, effectively hiding I / O latency. Actual measurements show that at a 120MHz clock frequency, compressing 680 bytes of data takes approximately 18ms, far less than the maximum waiting window of 60 seconds, meeting real-time requirements.

[0029] Furthermore, to address the issue of drastic fluctuations in the differential sequence and decreased compression efficiency caused by extreme load mutations, this invention introduces an adaptive compression mode switching mechanism. Before each compression, the MCU calculates the Euclidean distance between the current data block and the previous data block. ,in These are the normalized values ​​of the i-th physical quantity in the two data blocks (the normalization factor is the nominal value of the physical quantity). If D > θ (the threshold θ is set to 0.3), it is determined to be a sudden change condition, and differential preprocessing is skipped, and LZ77 compression is directly performed on the original data; otherwise, differential mode is enabled. This mechanism ensures that a better compression ratio can be obtained under both steady-state and transient conditions.

[0030] The improved LZ77 compression algorithm outputs a compressed data stream, formatted according to the standard LZ77 triplet notation: (offset, length, next character). The offset is represented by an 11-bit unsigned integer, ranging from 0 to 2047; the length is represented by a 4-bit unsigned integer, ranging from 3 to 18 (the minimum match length is set to 3 bytes); the next character is 1 byte of original data. When no match occurs, the original byte is output directly, and the length field is marked as 0. The compression process is implemented by MCU software, using a DMA controller to move the data to be compressed from flash memory to the SRAM working area. The compression result is temporarily stored in another SRAM buffer and written back to flash memory after the complete compressed package is generated. Actual measurements show that under typical rural transformer substation load curves, the compression ratio for a 680-byte original data block can reach 1:3.2, meaning the compressed size is approximately 212 bytes.

[0031] As one of the core innovations of this invention, the lightweight BeiDou protocol structurally trims and reconstructs the standard RDSS protocol stack, removing functional fields and signaling interactions unrelated to power metering services. For example... Figure 5 As shown, the lightweight protocol frame structure defined in this invention includes: a frame header (2 bytes), a terminal identifier (4 bytes), a data type identifier (1 byte), a compressed data payload (variable length, maximum 980 bytes), and a checksum (2 bytes). The frame header is fixed at 0x5AA5 and used for frame synchronization; the terminal identifier (24) adopts the State Grid unified coding rules and is a 32-bit unsigned integer, uniquely identifying each metering terminal; the data type identifier is used to distinguish between regular metering data, event alarm data, or acknowledgment data responding to master station commands, with a value of 0x01 indicating regular metering data; the checksum adopts the 16-bit CRC-CCITT polynomial of the ITU-T G.704 standard. Calculated and generated, with an initial value of 0xFFFF.

[0032] Furthermore, the lightweight BeiDou protocol eliminates the location reporting and two-way acknowledgment mechanisms found in the standard RDSS. In power metering applications, the terminal's geographical location is fixed and known, eliminating the need for coordinate information in each transmission. Simultaneously, given that satellite links primarily rely on unidirectional transmission and incur high retransmission costs, this invention employs a (Best-Effort) transmission strategy. It relies on frame integrity verification at the ground receiving station and data continuity detection at the master station to indirectly determine transmission reliability, rather than introducing ACK / NACK interactions at the link layer. This reduces the single-frame protocol overhead from 19 bytes to 9 bytes, increasing the effective payload ratio from approximately 98% to 99.1%. Within the 980-byte maximum payload limit, it can accommodate approximately 9 more bytes of effective information.

[0033] As another key feature of this invention, the BeiDou communication module employs a dedicated radio frequency chip conforming to the BeiDou-2 RDSS interface specification, and its baseband processor integrates a hardware acceleration engine for the lightweight protocol described in this invention. This engine implements the hardware logic for protocol encapsulation and decapsulation above the physical layer, including frame header insertion, CRC calculation, bit stuffing, and NRZI encoding. When the MCU sends a compressed data stream to the BeiDou communication module via the UART interface, the module automatically adds a terminal identifier and data type identifier, calculates the CRC checksum, and generates a complete lightweight protocol frame. Subsequently, this frame is modulated using GMSK (modulation index 0.5, symbol rate 16kbps) and then transmitted by an antenna driven by a power amplifier. The transmit power can be configured to 1W or 5W, corresponding to EIRPs of 36dBm or 43dBm respectively, meeting the link budget requirements under different terrain and obstruction conditions.

[0034] like Figure 6 As shown, the end-to-end workflow of the power metering communication method of the present invention is as follows: First, the power metering terminal performs a data acquisition task, periodically acquiring multi-dimensional power parameters such as voltage, current, and power; then, it performs classification caching, organizing the data according to physical quantity type and storing it in non-volatile memory; next, it enters an adaptive compression mode judgment, deciding whether to enable differential preprocessing based on load change characteristics; then, it performs protocol encapsulation, packaging the compressed data stream into a lightweight frame structure; then, it transmits the bit stream to the Beidou satellite via satellite transmission; the ground receiving station completes ground demodulation and parsing, including signal reception, frame synchronization, CRC check, and payload extraction; the power metering master station performs data decompression and verification, restoring the original data and verifying its rationality; finally, the master station analysis and command issuance module performs in-depth business processing and can issue remote control commands to the terminal.

[0035] The ground receiving station includes a BeiDou RDSS receiving antenna, a low-noise amplifier (LNA), a downconverter, an ADC sampling unit, a baseband demodulator, and a network interface unit. The receiving antenna is a right-hand circularly polarized (RHCP) planar array with a gain ≥10dBi; the LNA noise figure is ≤1.5dB; the downconverter downconverts the L-band (1610–1626.5MHz) signal to a 70MHz intermediate frequency; the ADC sampling rate is 20MHz with a 12-bit resolution; the baseband demodulator performs GMSK coherent demodulation, frame synchronization, CRC check, and lightweight protocol parsing. If the CRC check fails, the frame is discarded; if the check passes, the compressed data payload is extracted and uploaded to the power metering master station via a gigabit Ethernet interface. The ground receiving station can process no less than 50 short messages per second, with an average processing latency of less than 10ms.

[0036] The power metering master station is deployed in the provincial data center, running a Linux operating system and equipped with a multi-core CPU and high-speed SSD storage array. After receiving data streams from multiple ground receiving stations, the master station first routes the data to the corresponding virtual channel based on the terminal identifier; then, it calls the LZ77 decompression algorithm, consistent with the terminal, to restore the original structured data blocks; next, it performs data integrity verification, including timestamp continuity checks, physical quantity rationality verification (e.g., voltage should be within ±10% of the rated value), and monotonicity judgment of accumulated energy value; the verified data is written to a time-series database (e.g., InfluxDB) and triggers upper-layer application modules to perform load forecasting, line loss analysis, or abnormal power consumption detection. The master station can also generate downlink control commands, such as adjusting the sampling period, enabling event-triggered reporting, or remote meter calibration commands. These commands are encrypted and encapsulated into lightweight protocol frames, which are sent to the target terminal via the uplink from the ground station. The downlink frame structure is consistent with the uplink frame, except that the data type identifier is set to 0x02, and the payload content is the binary encoding of the command.

[0037] At the protocol level, the lightweight frame structure defined in this invention supports multiple terminals reusing the same ground receiving station resources. Because the terminal identifier is globally unique, the ground station can unambiguously distinguish data from different sources. Furthermore, the data type identifier field reserves extension bits to support new service types in the future (e.g., 0x03 for harmonic data, 0x04 for power quality events), demonstrating good scalability. The checksum uses a 16-bit CRC instead of a more complex hash algorithm, balancing error detection capability with computational overhead, resulting in a lower false detection rate than... .

[0038] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power metering communication method based on lightweight BeiDou protocol and data compression, characterized in that, Includes the following steps: The power metering terminal periodically collects multi-dimensional power parameters to form a structured time-series data sequence; The time-series data sequences are classified and organized according to the type of physical quantity, and cached in non-volatile memory; The improved LZ77 compression algorithm is used to perform lossless compression on the cached data. The improved LZ77 compression algorithm introduces differential preprocessing, field isolation matching and fixed-length sliding window on the basis of the traditional sliding window matching mechanism. The compressed data stream is encapsulated according to the lightweight BeiDou protocol frame structure to generate a bit stream that meets the modulation requirements of the BeiDou RDSS physical layer. The lightweight BeiDou protocol frame structure includes a frame header, terminal identifier, data type identifier, compressed data payload and check code, and the location information field and link layer response confirmation mechanism in the standard RDSS protocol are removed. The bit stream is modulated by the radio frequency front-end and then transmitted to the BeiDou satellite via the BeiDou communication module; The ground receiving station receives and demodulates the bit stream, performs frame synchronization, CRC check and protocol parsing, and extracts the compressed data payload; The power metering master station performs decompression and integrity verification on the compressed data payload, restores the original structured data blocks, and performs business analysis or issues commands.

2. The power metering communication method based on lightweight BeiDou protocol and data compression according to claim 1, characterized in that, The structured time-series data sequence consists of multiple structured data blocks. Each structured data block contains a timestamp, effective values ​​of three-phase voltage, effective values ​​of three-phase current, active power, reactive power, apparent power, power factor, frequency, and cumulative values ​​of forward / reverse active energy, totaling 68 bytes. The timestamp is a 4-byte Unix timestamp, voltage, current and power parameters are encoded as IEEE 754 single-precision floating-point numbers, and the cumulative energy value is stored as an 8-byte little-endian integer.

3. The power metering communication method based on lightweight BeiDou protocol and data compression according to claim 2, characterized in that, The differential preprocessing steps in the improved LZ77 compression algorithm include: Perform a first-order difference operation on the time series of each physical quantity to generate a difference sequence. Then, the differential sequence is compressed using LZ77. Furthermore, the field isolation matching step is limited to: sliding window matching is performed only between historical data of the same physical quantity type, that is, voltage sequences are matched only with historical voltage sequences, and current sequences are matched only with historical current sequences.

4. The power metering communication method based on lightweight BeiDou protocol and data compression according to claim 3, characterized in that, It also includes an adaptive compression mode switching mechanism: before each compression, the Euclidean distance between the current structured data block and the previous structured data block is calculated. ,in , For the first of the two data blocks The normalized value of each physical quantity; if D > threshold θ, then skip differential preprocessing and directly perform LZ77 compression on the original data; otherwise, enable differential preprocessing mode; the threshold θ is set to 0.

3.

5. The power metering communication method based on lightweight BeiDou protocol and data compression according to claim 1, characterized in that, In the lightweight BeiDou protocol frame structure, the frame header is fixed at 0x5AA5, the terminal identifier is a 32-bit unsigned integer following the State Grid's unified coding rules, and the data type identifier is a 1-byte field, where 0x01 represents regular metering data and 0x02 represents downlink control command receipt. The checksum uses the 16-bit CRC-CCITT polynomial of the ITU-T G.704 standard. Calculated and generated, with an initial value of 0xFFFF.

6. The power metering communication method based on lightweight BeiDou protocol and data compression according to claim 1, characterized in that, The power metering terminal sets up a circular buffer in the non-volatile memory. When the number of cached structured data blocks reaches a preset threshold or the maximum waiting time has elapsed since the last upload, the compression and upload process is triggered. The preset threshold is 10 data blocks, corresponding to 680 bytes of original data; the maximum waiting time is 60 seconds.

7. A power metering communication system for implementing the method as described in any one of claims 1 to 6, characterized in that, include: Electricity metering terminals are deployed on the user side or in distribution substations to collect, cache, and preprocess electricity parameters. The Beidou communication module is integrated inside the power metering terminal or connected externally via a UART interface. It has a built-in lightweight protocol hardware acceleration engine for performing protocol encapsulation, CRC calculation and GMSK modulation. BeiDou satellites, acting as space relay nodes, forward uplink short messages to ground receiving stations; The ground receiving station is equipped with a right-hand circularly polarized receiving antenna, a low-noise amplifier, a down-converter, an ADC sampling unit, and a baseband demodulator, which are used to complete signal reception, frame parsing, and payload extraction. The power metering master station, located in the provincial dispatch center, is used for data decompression, verification, storage, and instruction issuance.

8. The power metering communication system according to claim 7, characterized in that, The power metering terminal includes a high-precision metering chip, a microcontroller unit (MCU), a real-time clock (RTC), non-volatile memory, and a communication interface circuit. The high-precision metering chip supports the IEC 62053-22 standard, with a voltage channel sampling rate of 8kHz and a current channel dynamic range of no less than 5000:

1. The microcontroller unit uses an ARM Cortex-M4 core with a main frequency of no less than 120MHz, incorporates a hardware FPU and CRC acceleration engine, and runs a real-time operating system. The non-volatile memory is an SPI serial flash memory with a capacity of no less than 8MB.

9. The power metering communication system according to claim 8, characterized in that, The microcontroller unit employs a dual-buffered pipeline architecture when performing compression: while the DMA controller moves the data to be compressed from non-volatile memory to SRAM buffer A, the CPU compresses the previous batch of data in parallel and writes the result to SRAM buffer B; after compression is completed, the DMA moves the result back to non-volatile memory, thus achieving parallelization of data moving and compression processing.

10. The power metering communication system according to claim 7, characterized in that, The baseband processor of the Beidou communication module has a built-in lightweight protocol encapsulation unit implemented with hard logic. When it receives the compressed data stream sent by the MCU through the UART interface, it automatically adds a terminal identifier and a data type identifier, inserts a frame header, calculates the checksum, and completes NRZI encoding and GMSK modulation. The symbol rate of the GMSK modulation is 16kbps and the modulation index is 0.

5. The transmit power can be configured to 1W or 5W, corresponding to EIRP of 36dBm or 43dBm, respectively.

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