A dual-mode communication module, system and time service method based on Beidou time service

Abstract

The application relates to the technical field of electric power communication, and particularly discloses a dual-mode communication module, a system and a timing method based on Beidou timing, which comprises a base meter weak current interface unit, a Beidou timing unit, a carrier wave communication unit, a radio frequency communication unit, a strong current interface unit, a zero-crossing detection unit, a dual-mode MCU and a power supply unit; the Beidou satellite timing channel is integrated in the dual-mode communication module, a high-reliability clock source is provided for the dual-mode MCU, and all devices in a local communication network are subjected to full-area high-precision time synchronization through carrier wave and radio frequency dual-mode communication network, so that the technical problems that the timing mode in the existing power grid power consumption information collection system still has the problems of great difficulty in time synchronization of multiple devices and low timing precision are effectively solved, the module meets the electric energy meter interface specification, can be used immediately after being plugged in, and operation and maintenance cost can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of power communication technology, and in particular to a dual-mode communication module, system and timing method based on BeiDou timing. Background Technology

[0002] In constructing a new power system architecture integrating power generation, grid, load, and storage, the clock synchronization accuracy and reliability of metering and sensing equipment directly affect the coordinated regulation efficiency of flexible resources such as distributed photovoltaics and electric vehicles. Clock anomalies not only lead to the failure of the dynamic power supply and demand balance mechanism but may also trigger systemic safety risks such as relay protection malfunctions and voltage over-limits. Currently, time synchronization schemes mainly include pulse time synchronization, serial port message time synchronization, network time synchronization, and base station time synchronization. For example, patent application CN104483649A proposes a high-precision time synchronization method for electricity meters, which achieves time synchronization by comparing the clock system time with the electricity meter system time. However, existing time synchronization methods in power grid electricity consumption information collection systems still suffer from problems such as difficulty in synchronizing multiple devices and low time synchronization accuracy. Summary of the Invention

[0003] The main objective of this invention is to propose a dual-mode communication module, system, and timing method based on BeiDou timing, aiming to solve the technical problems of high difficulty in synchronizing the time of multiple devices and low timing accuracy in the existing power grid electricity consumption information collection system.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a dual-mode communication module based on BeiDou timing, comprising a base meter weak current interface unit, a BeiDou timing unit, a carrier communication unit, a radio frequency communication unit, a strong current interface unit, a zero-crossing detection unit, a dual-mode MCU, and a power supply unit;

[0005] The first end of the power supply unit and the first end of the carrier communication unit are connected to the first end of the base meter weak current interface unit. The second end of the power supply unit is connected to the power input terminal of the dual-mode MCU. The second end of the base meter weak current interface is connected to the communication I / O port of the dual-mode MCU. The second end of the carrier communication unit is connected to the carrier communication port of the dual-mode MCU. The third end is connected to the first end of the high current interface unit. The first end of the zero-crossing detection unit is connected to the second end of the high current interface unit. The second end is connected to the zero-crossing signal receiving port of the dual-mode MCU. The first end of the radio frequency communication unit is connected to the radio frequency communication port of the dual-mode MCU. The second end is connected to the HRF antenna. The first end of the Beidou timing unit is connected to the Beidou communication port of the dual-mode MCU. The second end is connected to the Beidou antenna.

[0006] Furthermore, the BeiDou timing unit includes a BeiDou timing chip, a decoupling circuit, an RC filter circuit, a BeiDou signal output matching circuit, a BeiDou antenna interface circuit, and a filter matching circuit. The first terminal of the decoupling circuit is connected to a 3.3V voltage input, and the second terminal is connected to the main power input pin of the BeiDou timing chip. The first terminal of the RC filter circuit is connected to the dual-mode MCU, and the second terminal is connected to the external reset signal receiving pin of the BeiDou timing chip. The first terminal of the BeiDou signal output matching circuit is connected to the BeiDou antenna interface circuit, and the second terminal is connected to the antenna input pin of the BeiDou timing chip. The first terminal of the filter matching circuit is connected to the first terminal of the BeiDou signal output matching circuit, and the second terminal is connected to the BeiDou antenna power supply pin of the BeiDou timing chip.

[0007] Furthermore, the carrier communication unit includes a carrier transmitting circuit, a carrier receiving circuit, and a carrier coupling circuit; the carrier communication port includes a carrier signal transmitting end and a carrier signal receiving end; the first end of the carrier transmitting circuit is connected to the carrier signal transmitting end, and the second end is connected to the first end of the carrier coupling circuit; the second end of the carrier coupling circuit is connected to the first end of the carrier receiving circuit, and the third end is connected to the high-voltage interface unit; the second end of the carrier receiving circuit is connected to the carrier signal receiving end.

[0008] Furthermore, the carrier transmission circuit includes a carrier PA chip U2, resistors Re, Rf, Rg, R5, R6, capacitors C15, C16, C17, C18, C19, TVS transistors TVS1 and TVS2; the first end of capacitor C15 is connected to the non-inverting input of the carrier signal transmission pin of the dual-mode MCU, and the second end is connected to the A-channel non-inverting analog signal input pin of the carrier PA chip U2; the first end of capacitor C16 is connected to the inverting input of the carrier signal transmission pin of the dual-mode MCU, and the second end is connected to the B-channel non-inverting analog signal input pin of the carrier PA chip U2; the first ends of resistors Re and R5 are both connected to the A-channel signal output pin of the carrier PA chip U2; resistor R5... The second terminal of resistor R1 and the first terminal of TVS1 are both connected to the first terminal of capacitor C18; the second terminal of capacitor C18 is the non-inverting transmission port of the carrier transmission channel; the second terminal of resistor Re and the first terminal of capacitor C17 are both connected to the inverting analog signal input pin of channel A of carrier PA chip U2; the second terminal of capacitor C17 is connected to the first terminal of resistor Rg; the second terminal of resistor Rg and the first terminal of resistor Rf are both connected to the inverting analog signal input pin of channel B of carrier PA chip U2; the second terminal of resistor Rf and the first terminal of resistor R6 are both connected to the signal output pin of channel B of carrier PA chip U2; the second terminal of resistor R6 and the first terminal of TVS1 are both connected to the first terminal of capacitor C19; the second terminal of capacitor C19 is the inverting transmission port of the carrier transmission channel; the second terminals of TVS1 and TVS2 are both grounded.

[0009] Furthermore, the carrier receiving circuit includes resistors R7 and R8, capacitors C20, C21, C22, C23, and C24, inductors L4, L5, and L6, and TVS transistors TVS3 and TVS4. The first end of resistor R7 is connected to the non-inverting receiving port of the carrier receiving channel, and the second end is connected to the first end of capacitor C20. The second end of capacitor C20 is connected to the first end of capacitor C22. The second end of capacitor C22 is connected to the first end of inductor L5. The second end of inductor L5 is connected to the first end of TVS transistor TVS3. The first end of resistor R8 is connected to the inverting receiving port of the carrier receiving channel, and the second end is connected to capacitor C20. The first terminal of capacitor C21 is connected to the first terminal of capacitor C23; the second terminal of capacitor C23 is connected to the first terminal of inductor L6; the second terminal of inductor L6 is connected to the first terminal of TVS transistor TVS4; the second terminals of both TVS transistors TVS3 and TVS4 are grounded; the first terminal of inductor L4 is connected to the second terminal of capacitor C20, and the second terminal is connected to the second terminal of capacitor C21; the first terminal of capacitor C24 is connected to the second terminal of inductor L5, and the second terminal is connected to the second terminal of inductor L6; the second terminal of inductor L5 is connected to the inverting input of the carrier signal receiving pin of the dual-mode MCU, and the second terminal of inductor L6 is connected to the non-inverting input of the carrier signal receiving pin of the dual-mode MCU.

[0010] Furthermore, the carrier coupling circuit includes a coupling transformer T1, a safety capacitor Cx1, a TVS diode TVS5, and a TVS diode TVS6. The first end of the coupling transformer T1 is connected to the carrier transceiver channel, and the second end is connected to the high-voltage interface unit. The safety capacitor Cx1 is connected in series in the coil circuit of the second end of the coupling transformer T1, the TVS diode TVS5 is connected in parallel across the coil of the first end of the coupling transformer T1, and the TVS diode TVS6 is connected in parallel across the coil of the second end of the coupling transformer T1.

[0011] Furthermore, the radio frequency communication unit includes a radio frequency matching circuit and a radio frequency switch. The first end of the radio frequency matching circuit is connected to the radio frequency communication port, the second end is connected to the first end of the radio frequency switch, and the second end of the radio frequency switch is connected to the HRF antenna.

[0012] Furthermore, the base meter low-voltage interface unit includes a level conversion circuit and an interface protection circuit; the first end of the interface protection circuit is connected to the base meter low-voltage interface, and the second end is connected to the first end of the level conversion circuit; the second end of the level conversion circuit is connected to the communication I / O port of the dual-mode MCU.

[0013] Secondly, the present invention also provides a dual-mode communication system based on BeiDou timing. The system includes a master node, a proxy node, and sub-nodes, wherein the sub-nodes include the dual-mode communication module based on BeiDou timing as described in the first aspect.

[0014] Thirdly, the present invention also provides a timing method for a dual-mode communication module based on BeiDou timing, the method being applied to the dual-mode communication system based on BeiDou timing as described in the second aspect, the method comprising:

[0015] Step S1: The dual-mode communication module parses the perpetual calendar entry from the beacon frame sent by the master node or the proxy node, and when the deviation between the perpetual calendar entry and the BeiDou clock exceeds a preset threshold, it sends a time synchronization event message carrying the BeiDou clock and the first network reference time to the master node of the local station area in the CSMA time slot.

[0016] Step S2: The master node synchronizes its time with the BeiDou clock and the first network reference time, and sends a beacon message carrying the calibrated second real-time clock and the second network reference time to the master node's sub-nodes in the beacon time slot;

[0017] Step S3: The child node synchronizes its time according to the second real-time clock and the second network reference time.

[0018] The aforementioned dual-mode communication module, system, and timing method based on BeiDou timing integrates the BeiDou timing unit into the dual-mode communication module. Through the coordinated connection of the base station weak current interface unit, power supply unit, carrier communication unit, radio frequency communication unit, strong current interface unit, zero-crossing detection unit, and dual-mode MCU, a modular structure integrating high-precision BeiDou satellite timing and a dual-mode communication network is formed. This module utilizes the BeiDou timing unit as a high-precision clock data source, directly providing a nanosecond-level time reference to the dual-mode MCU. Through the dual-mode communication network composed of the carrier communication unit and the radio frequency communication unit, the synchronized BeiDou time is broadcast to other devices within the local communication network. This effectively overcomes the shortcomings of existing pulse time synchronization, serial port message time synchronization, network time synchronization, and base station time synchronization methods when synchronizing multiple devices, such as limited transmission distance, low timing accuracy, dependence on network stability, and poor environmental adaptability. It significantly reduces the difficulty of time synchronization between multiple devices and greatly improves the accuracy and reliability of clock synchronization across the entire distribution area. Meanwhile, the module adopts a design that conforms to the electricity meter interface specifications, enabling plug-and-play functionality and facilitating the replacement of existing electricity meter communication modules with inaccurate clocks. This reduces maintenance costs and, by leveraging the wide coverage and all-weather capability of BeiDou satellite signals, solves the problem of electricity meters in remote areas being unable to accurately synchronize their time due to network blind spots. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a dual-mode communication module based on BeiDou time synchronization in one embodiment.

[0020] Figure 2 This is a schematic diagram of the structure of a dual-mode communication module based on BeiDou time synchronization in another embodiment;

[0021] Figure 3 This is a schematic diagram of the peripheral circuitry of a dual-mode MCU in one embodiment;

[0022] Figure 4 This is a schematic diagram of the structure of the BeiDou timing unit in one embodiment;

[0023] Figure 5 This is a schematic diagram of the carrier transmission circuit in one embodiment;

[0024] Figure 6 This is a schematic diagram of the carrier receiving circuit in one embodiment;

[0025] Figure 7 This is a schematic diagram of the carrier coupling circuit in one embodiment;

[0026] Figure 8 This is a schematic diagram of the radio frequency matching circuit in one embodiment;

[0027] Figure 9 This is a schematic diagram of the zero-crossing detection unit in one embodiment;

[0028] Figure 10 This is a schematic diagram of the structure of the base meter low-voltage interface unit in one embodiment;

[0029] Figure 11 This is a schematic diagram of the power supply unit in one embodiment;

[0030] Figure 12 This is a schematic diagram of the structure of a 12V input power supply filter circuit in one embodiment;

[0031] Figure 13 This is a schematic diagram of the 3.3V output filter circuit in one embodiment;

[0032] Figure 14 This is a schematic diagram of the wireless analog front-end power supply filter circuit in one embodiment;

[0033] Figure 15 This is a schematic diagram of the power supply filter circuit for the carrier analog front end in one embodiment;

[0034] Figure 16 This is a schematic diagram of a dual-mode communication system based on BeiDou time synchronization in one embodiment.

[0035] Figure 17 This is a schematic diagram of the timing method of a dual-mode communication module based on BeiDou timing in one embodiment;

[0036] Figure 18 This is a simplified flowchart illustrating the collimation message sending and receiving process in one embodiment.

[0037] Explanation of icon numbers:

[0038] Carrier communication unit 110; radio frequency communication unit 120; decoupling circuit 131; RC filter circuit 132; Beidou signal output matching circuit 133; Beidou antenna interface circuit 134; filter matching circuit 135. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figure 1 As shown, this embodiment provides a dual-mode communication module based on BeiDou timing, including a base meter weak current interface unit, a BeiDou timing unit, a carrier communication unit, a radio frequency communication unit, a high current interface unit, a zero-crossing detection unit, a dual-mode MCU, and a power supply unit. The first end of the power supply unit and the first end of the carrier communication unit are connected to the first end of the base meter weak current interface unit. The second end of the power supply unit is connected to the power input terminal of the dual-mode MCU. The second end of the base meter weak current interface unit is connected to the communication I / O port of the dual-mode MCU. The second end of the carrier communication unit is connected to the carrier communication port of the dual-mode MCU. The third end of the carrier communication unit is connected to the first end of the high current interface unit. The first end of the zero-crossing detection unit is connected to the second end of the high current interface unit. The second end of the zero-crossing detection unit is connected to the zero-crossing signal receiving port of the dual-mode MCU. The first end of the radio frequency communication unit is connected to the radio frequency communication port of the dual-mode MCU. The second end of the radio frequency communication unit is connected to the HRF antenna. The first end of the BeiDou timing unit is connected to the BeiDou communication port of the dual-mode MCU. The second end of the BeiDou antenna is connected to the BeiDou antenna.

[0042] The base station interface unit is used to connect and communicate between the module and the energy meter, supporting various common communication interface protocols, such as Power Line Carrier Communication (PLC), facilitating interfacing with other power equipment and communication networks. The power supply unit provides a stable power supply to the entire module, employing efficient power management chips and circuit design to ensure a clean and stable power supply to the chip and other hardware components under different operating conditions. The dual-mode MCU, as the core component, undertakes multiple key functions such as communication, sensing, computing, and control. It is used to switch between Power Line Carrier Communication (PLC) and Radio Frequency Communication (RF) and to transmit data. It can automatically select the optimal communication method according to changes in the actual communication environment, ensuring the stability and efficiency of data transmission. The carrier communication unit uses a dedicated carrier power amplifier (PA) to amplify the signal, significantly increasing the signal amplitude to ensure long-distance signal propagation while effectively resisting interference and loss encountered during transmission. The carrier communication unit also filters and preprocesses the received carrier signal, filtering out interference and noise signals coupled from the power line to meet the input requirements of the chip's carrier analog front-end system. The radio frequency (RF) communication unit is used to transmit, receive, and process RF communication signals. The zero-crossing detection unit provides accurate zero-crossing signals for the dual-mode communication module, enabling effective phase identification and topology analysis. The BeiDou timing unit calibrates the time of the energy meter based on BeiDou satellite signals to achieve high-precision time synchronization of the communication network.

[0043] In a preferred embodiment, the dual-mode MCU employs a self-developed dual-mode communication chip, model WTZ30S. In the analog signal receiving section, this chip integrates a high-performance receiver analog front-end (R-AFE), including modules such as a low-noise amplifier, low-pass filter, programmable gain amplifier, and high-precision low-noise ADC. This enables amplification, filtering, and high-precision sampling of the received signal, suppressing out-of-band noise while improving the distortion-free pickup capability of weak signals. In the analog signal transmitting section, the chip integrates a high-performance transmitter analog front-end (T-AFE), including a high-precision DAC, programmable gain amplifier, low-pass filter, and gain driver, effectively ensuring the quality and power of the transmitted signal. In the digital transmitting and receiving section, the chip features a digital front-end (DFE) integrating digital filtering, digital programmable gain amplifier, and digital frequency conversion functions, further enhancing the reception capability of weak signals. In the digital modulation and demodulation section, the chip significantly improves signal demodulation capabilities through high-precision synchronization algorithms, channel estimation and equalization algorithms, and Turbo channel encoding and decoding design.

[0044] The peripheral circuits of a dual-mode MCU are as follows Figure 3As shown. Pin 34 of the dual-mode MCU serves as the reset signal output port (B_RST) of the BeiDou timing unit, pin 17 serves as the serial port receiving pin (B_RXD) of the BeiDou timing unit, pin 2 serves as the serial port transmitting pin (B_TXD) of the BeiDou timing unit, and pin 2 is grounded through resistor R913, the resistance of which is preferably 5.1kΩ. Pin 6 is the carrier signal transmitting pin (PLC_TXD), pin 38 is the carrier signal receiving pin (PLC_RXD), pin 18 is the RF signal transmitting pin (RFO), pin 20 is the 3.3V RF power input pin (RF_VDD33), pin 22 is the 1.8V RF power input pin (RF_VDD33), pin 25 is the 1.1V RF power input pin (RF_VDD11), pin 27 is the RF signal receiving pin (RFI), and pin 3 is the zero-crossing signal (ZC_A) receiving pin.

[0045] Specifically, the dual-mode MCU reads high-precision BeiDou time information from the BeiDou timing unit and updates its local real-time clock (RTC) and network reference time (NTB) accordingly, ensuring that the module's own clock is synchronized with the BeiDou satellite system. After synchronizing its own clock, the dual-mode MCU also continuously monitors beacon frames sent by the master or proxy nodes in its dual-mode communication network, parses the perpetual calendar entries and network time information carried within them, and automatically triggers a time synchronization event reporting process when the deviation between the parsed beacon frame time and its own BeiDou clock exceeds a preset threshold, carrying the current BeiDou clock value and the local first network... The time synchronization event reporting message is sent to the master node of the local area via unicast in the CSMA time slot. Subsequently, after receiving the acknowledgment frame returned by the master node and the calibrated second real-time clock and second network reference time carried in the subsequent beacon frame, the dual-mode MCU fine-tunes its local real-time clock and network reference time again to achieve precise synchronization with the master node. In addition, if the dual-mode communication module acts as a proxy node in the network, the dual-mode MCU will also forward beacon frames or actively send time synchronization information to its subordinate sub-nodes based on its own synchronized BeiDou clock, assisting in achieving high-precision time synchronization throughout the entire area. Through the above process, the dual-mode communication module equipped with the BeiDou time synchronization unit can not only achieve high-precision self-synchronization of its own clock, but also actively participate in the time synchronization mechanism of the dual-mode communication network, acting as a time source to provide time synchronization services to other nodes in the network, thereby improving the time synchronization accuracy and reliability of the entire electricity information collection system.

[0046] Furthermore, such as Figure 4As shown, the BeiDou timing unit includes a BeiDou timing chip D1, a decoupling circuit, an RC filter circuit, a BeiDou signal output matching circuit, a BeiDou antenna interface circuit, and a filter matching circuit. The first terminal of the decoupling circuit is connected to a 3.3V voltage input, and the second terminal is connected to the main power input pin (VBAT) of the BeiDou timing chip D1. The first terminal of the RC filter circuit is connected to the dual-mode MCU, and the second terminal is connected to the external reset signal receiving pin (RESET_N) of the BeiDou timing chip D1. The first terminal of the BeiDou signal output matching circuit is connected to the BeiDou antenna interface circuit, and the second terminal is connected to the antenna input pin (ANT_GNSS) of the BeiDou timing chip D1. The first terminal of the filter matching circuit is connected to the first terminal of the BeiDou signal output matching circuit, and the second terminal is connected to the BeiDou antenna power supply pin (VCC_RF) of the BeiDou timing chip D1. The decoupling circuit filters out power supply noise to ensure a clean and reliable power supply to the module. The RC filter circuit filters out noise from the external reset signal to prevent external interference from causing the BeiDou module to reset. The filter matching circuit filters out noise from the antenna power supply. The BeiDou signal output matching circuit is used to eliminate signal reflection through impedance matching, ensuring that the BeiDou radio frequency signal is transmitted efficiently and without loss from the BeiDou antenna to the BeiDou timing chip D1.

[0047] Furthermore, the BeiDou timing unit may also include shorting resistors R310 and R308, and a TVS diode V30. The first terminal of shorting resistor R310 is connected to the 3.3V voltage input, and the second terminal is connected to the backup power input pin (VBACKUP) of the BeiDou timing chip D1. The first terminal of shorting resistor R308 is connected to the second terminal of the filter matching circuit, and the second terminal is connected to the BeiDou antenna power supply pin (VCC_RF) of the BeiDou timing chip D1. The shorting resistors are mainly used for circuit debugging and functional configuration. By default, they act as direct jumpers to establish an electrical path. They can be removed when needed to disconnect the corresponding power supply branch, facilitating fault isolation, power consumption testing, or adaptation to different power supply requirements. For example, when testing the power consumption of the BeiDou timing chip D1 or isolating faults, resistor R310 can be removed to disconnect this branch; when disconnecting the antenna power supply for debugging or adaptation to a passive antenna, resistor R308 can be removed. The first terminal of TVS diode V30 is connected to the first terminal of the BeiDou signal output matching circuit, and the second terminal is grounded. The TVS diode V30 is an electrostatic discharge (ESD) protection device for the BeiDou radio frequency signal, used to prevent damage to the BeiDou timing unit from electrostatic discharge. Preferably, the TVS diode V30 is model LXES15AAA1.

[0048] In a preferred embodiment, such as Figure 4As shown, the preferred BeiDou timing chip D1 is the TAU1113 model. This chip boasts excellent compatibility, simultaneously supporting B1I and B1C satellite signals from both the BeiDou-2 and BeiDou-3 systems, achieving wider and more stable signal coverage. Furthermore, it integrates A-BDS assisted positioning functionality, effectively improving positioning speed and accuracy. In terms of performance, this chip achieves a time accuracy of up to 20ns and a sensitivity of -152dBm, ensuring accurate and reliable timing services even in complex environments. Pins 3 and 2 of the BeiDou timing chip serve as transceiver pins for serial communication with the dual-mode MCU, pin 4 is the pulse-per-second (PPS) signal receiver pin, pin 6 is the backup power input pin, pin 8 is the main power input pin, pin 11 is the antenna input pin, pin 14 is the BeiDou antenna power supply pin, and pin 18 is the wake-up signal input pin, used to receive the BOOT wake-up signal. The decoupling circuit includes capacitors C313 and C314. The first terminals of both capacitors C313 and C314 are connected to a 3.3V voltage source, and the second terminals of both capacitors C313 and C314 are grounded. The capacitance of capacitor C313 is preferably 10uF, and the capacitance of capacitor C314 is preferably 0.1uF. The RC filter circuit includes resistor R316 and capacitor C312. The first terminal of resistor R316 is connected to the reset signal output pin (B_RST) of the dual-mode MCU. The second terminals of resistor R316 and capacitor C312 are both connected to the external reset signal receiving pin (RESET_N) of the Beidou timing chip D1. The second terminal of capacitor C312 is grounded. The resistance of resistor R316 is preferably 100Ω, and the capacitance of capacitor C312 is preferably 0.1uF. The BeiDou signal output matching circuit includes capacitors C308, C306, C309, C310, and resistor R313. The first terminal of capacitor C308 is connected to the antenna input pin (ANT_GNSS) of the BeiDou timing chip D1, and the second terminal is connected to the first terminal of capacitor C306. The second terminal of capacitor C306 is grounded. The first terminal of resistor R313 is connected to the second terminal of capacitor C308, and the second terminal is connected to the first terminal of capacitor C310. The first terminal of capacitor C309 is connected to the first terminal of capacitor C310, and the second terminal is grounded. The second terminal of capacitor C310 is grounded through a TVS diode V30. The capacitance values ​​of capacitors C308 and C310 are preferably 100pF, while capacitors C306, C309, and resistor R313 are optional. The BeiDou antenna interface circuit is the BeiDou antenna pad U12, compatible with both internal and external antennas. Pin 1 of the BeiDou antenna pad U12 is connected to the second terminal of capacitor C310, and pins 2 and 4 are grounded. The filter matching circuit includes inductor L301 and capacitor C307. The first ends of inductor L301 and capacitor C307 are both connected to the Beidou antenna power supply pin (VCC_RF) of Beidou timing chip D1 through resistor R308.The inductor L301 is preferably a magnetic core inductor with an inductance of 39nH, and the capacitor C307 is preferably 0.1uF.

[0049] After receiving a BeiDou satellite signal that meets the amplitude and signal-to-noise ratio requirements, the BeiDou timing chip D1 internally performs low-noise amplification, down-conversion, analog-to-digital conversion, and baseband processing to demodulate the time information from the BeiDou satellite signal, thereby recovering a high-precision time reference. This time reference is output to the upper-level system through the communication interface between the BeiDou timing chip D1 and the dual-mode MCU to complete the time synchronization function.

[0050] Furthermore, such as Figure 2 As shown, the carrier communication unit includes a carrier transmitting circuit, a carrier receiving circuit, and a carrier coupling circuit. The carrier communication port includes a carrier signal transmitting end and a carrier signal receiving end. The first end of the carrier transmitting circuit is connected to the carrier signal transmitting end, and the second end is connected to the first end of the carrier coupling circuit. The second end of the carrier coupling circuit is connected to the first end of the carrier receiving circuit, and the third end is connected to the high-voltage interface unit. The second end of the carrier receiving circuit is connected to the carrier signal receiving end. The carrier transmitting circuit uses a dedicated carrier power amplifier (PA) to significantly boost the signal amplitude, ensuring long-distance signal propagation and effectively resisting interference and loss during transmission. The carrier receiving circuit receives carrier signals from other devices, demodulates and processes them, and extracts the data information contained within. The carrier coupling circuit performs isolation, impedance matching, and signal coupling; its design directly affects the carrier communication performance of the entire module. Design principles include: high coupling efficiency, sufficient coupling bandwidth (must meet the requirements of high-frequency carrier signal transmission), good impedance and frequency characteristics to minimize operating attenuation; at the same time, the communication circuit and power line must be isolated to ensure that no high voltage or large current occurs in the communication circuit and to ensure safety in use; in addition, protective measures must be provided to prevent overvoltage or overcurrent caused by induction or short circuit from damaging other devices in the carrier path.

[0051] In a preferred embodiment, such as Figure 5As shown, the carrier transmission circuit includes a carrier PA chip U2, resistors Re, Rf, Rg, R5, R6, capacitors C15, C16, C17, C18, C19, TVS transistors TVS1 and TVS2. The first terminal of capacitor C15 is connected to the non-inverting input (TX_P) of the carrier signal transmission pin of the dual-mode MCU, and the second terminal is connected to the non-inverting analog signal input pin (VINA+) of channel A of the carrier PA chip U2. The first terminal of capacitor C16 is connected to the inverting input (TX_N) of the carrier signal transmission pin of the dual-mode MCU, and the second terminal is connected to the non-inverting analog signal input pin (VINB+) of channel B of the carrier PA chip U2. The first terminals of resistors Re and R5 are both connected to the signal output pin (OUTA) of channel A of the carrier PA chip U2. The second terminal of resistor R5 and the first terminal of TVS transistor TVS2 are both connected to the first terminal of capacitor C18. The second terminal of capacitor C18 is the carrier transmission pin. The non-inverting transmit port of the transmission channel is connected to the second terminal of resistor Re and the first terminal of capacitor C17. The second terminal of capacitor C17 is connected to the first terminal of resistor Rg. The second terminals of resistor Rg and resistor Rf are both connected to the inverting analog signal input pin (VINB-) of the B channel of the carrier PA chip U2. The second terminals of resistor Rf and resistor R6 are both connected to the signal output pin (OUTB) of the B channel of the carrier PA chip U2. The second terminal of resistor R6 and the first terminal of TVS transistor TVS1 are both connected to the first terminal of capacitor C19. The second terminal of capacitor C19 is the inverting transmit port of the carrier transmission channel. The second terminals of TVS transistors TVS1 and TVS2 are both grounded. Capacitors C15 and C16 are DC blocking capacitors, capacitor C17 is a feedback filter capacitor, resistors R5 and R6 are current-limiting resistors, and TVS transistors TVS1 and TVS2 are used to absorb surge spikes to protect the circuit. Specifically, the carrier transmission signals (TX_P and TX_N) are amplified by the differential operational amplifier inside the carrier PA chip U2 and then output. The amplification factor can be set by adjusting the resistance values ​​of resistors Re, Rf, and Rg.

[0052] The dual-mode communication module in this embodiment uses a THS6212 carrier PA chip. This chip features high linearity, low distortion, and a wide voltage range, effectively resisting interference and losses encountered during transmission. In terms of amplification performance, the THS6212 exhibits excellent power amplification performance under different input signal frequencies and amplitudes, meeting the requirements of long-distance communication. Regarding efficiency, the THS6212 demonstrates high efficiency under different operating conditions, effectively reducing system power consumption. In terms of linearity, the THS6212 produces minimal distortion during signal amplification, and the spectral characteristics of the output signal are essentially consistent with the input signal.

[0053] In a preferred embodiment, such as Figure 6 As shown, the carrier receiving circuit includes resistors R7 and R8, capacitors C20, C21, C22, C23, and C24, inductors L4, L5, and L6, and TVS transistors TVS3 and TVS4. The first terminal of resistor R7 is connected to the non-inverting receiver port (RX_P) of the carrier receiving channel, and the second terminal is connected to the first terminal of capacitor C20. The second terminal of capacitor C20 is connected to the first terminal of capacitor C22. The second terminal of capacitor C22 is connected to the first terminal of inductor L5. The second terminal of inductor L5 is connected to the first terminal of TVS transistor TVS3. Resistor R8... The first terminal is connected to the inverting receiver port (RX_N) of the carrier receiving channel. The second terminal is connected to the first terminal of capacitor C21. The second terminal of capacitor C21 is connected to the first terminal of capacitor C23. The second terminal of capacitor C23 is connected to the first terminal of inductor L6. The second terminal of inductor L6 is connected to the first terminal of TVS transistor TVS4. The second terminals of both TVS transistors TVS3 and TVS4 are grounded. The first terminal of inductor L4 is connected to the second terminal of capacitor C20, and the second terminal is connected to the second terminal of capacitor C21. The first terminal of capacitor C24 is connected to the second terminal of inductor L5, and the second terminal is connected to the second terminal of inductor L6. The second terminal of inductor L5 is connected to the inverting input (RX_N_IN) of the carrier signal receiving pin of the dual-mode MCU, and the second terminal of inductor L6 is connected to the non-inverting input (RX_P_IN) of the carrier signal receiving pin of the dual-mode MCU.

[0054] Specifically, the carrier received signal, after passing through current-limiting resistors R7 and R8, enters a high-order bandpass filter composed of inductors L4, L5, and L6 and capacitors C20, C21, C22, C23, and C24. This filter filters the received signal according to the set center frequency and bandwidth, allowing only signals within a specific frequency range to pass, thereby effectively filtering out out-of-band noise and interference and improving the quality of the received signal. When the signal attenuates due to long-distance transmission, a higher quality signal is more beneficial for subsequent amplification and processing, thus improving the module's receiving sensitivity and communication reliability under signal attenuation conditions. The signal after high-order filtering is then clamped and limited by TVS diodes TVS3 and TVS4 to control the signal voltage within the allowable input range of the dual-mode MCU chip, preventing damage from overvoltage.

[0055] In a preferred embodiment, such as Figure 7As shown, the carrier coupling circuit includes a coupling transformer T1, a safety capacitor Cx1, and TVS transistors TVS5 and TVS6. The first end (primary side) of the coupling transformer T1 is connected to the carrier transceiver channel, and the second end (secondary side) is connected to the high-voltage interface unit. The safety capacitor Cx1 is connected in series in the coil circuit of the second end. TVS transistor TVS5 is connected in parallel across the coil of the first end of the coupling transformer T1, and TVS transistor TVS6 is connected in parallel across the coil of the second end of the coupling transformer T1. The safety capacitor Cx1, utilizing its low ESR characteristics, presents a low-impedance path for high-frequency communication signals, allowing them to pass smoothly, while presenting a high impedance for power frequency signals, thus avoiding power frequency energy loss. The coupling transformer T1 uses the principle of electromagnetic induction to achieve signal transmission across voltage levels, while effectively isolating common-mode noise. TVS transistors TVS5 and TVS6 constitute a voltage clamping protection circuit to limit transient overvoltages and protect downstream devices.

[0056] like Figure 2 As shown, the RF communication unit includes an RF matching circuit and an RF switch. The first terminal of the RF matching circuit is connected to the RF communication port, and the second terminal is connected to the first terminal of the RF switch. The second terminal of the RF switch is connected to the HRF antenna. The core design goal of this unit is to achieve stable and efficient transmission and reception of RF signals in complex electromagnetic environments. The design process fully considers key factors such as signal gain, attenuation, and matching, and employs advanced circuit technology and optimization measures. In this embodiment, the dual-mode MCU integrates a low-noise amplifier (LNA) and a filter: the LNA amplifies the received weak RF signal with minimal introduction of additional noise; the filter removes out-of-band noise and interference, ensuring that only useful RF signals pass through. Therefore, wireless communication can be achieved with only simple external circuitry.

[0057] In a preferred embodiment, such as Figure 8As shown, the RF matching circuit includes inductors L7, L8, L9, L10, and L11, capacitors C25, C26, C27, C28, C29, C30, C31, C32, and C33, resistors R2 and R9, and a TVS transistor TVS7. The first terminals of resistor R9 and TVS7 are both connected to the HRF antenna. The second terminal of resistor R9 is connected to the first terminal of capacitor C33. The second terminal of capacitor C33 is connected to the antenna connection pin (RFC) of RF switch chip U3. The first terminal of capacitor C32 is connected to the first control pin (VC1) of RF switch chip U3. The second terminals of capacitor C32 and TVS7 are both grounded. The first terminal of capacitor C31 is grounded, and the second terminal is connected to the second control pin (VC2) of RF switch chip U3. The first terminal of capacitor C30 is connected to the RF receiver pin (RF2) of RF switch chip U3. The second terminal of capacitor C30 is connected to the first terminal of inductor L11. The second terminal of inductor L11 is connected to the first terminal of capacitor C27. The second terminal of capacitor C27 is connected to the first terminal of inductor L8. The second terminal of inductor L8... The first terminal of capacitor C25 is connected to the first terminal of inductor L7. The second terminal of inductor L7 is connected to the RF power input pins of the dual-mode MCU (including the 3.3V, 1.8V, and 1.1V RF power input pins). Capacitor C28 is connected in parallel across inductor L11, and capacitor C26 is connected in parallel across inductor L8. The second terminal of capacitor C25 is connected to the RF signal transmit pin (RF0) of the dual-mode MCU. The first terminal of capacitor C29 is connected to the RF transmit pin (RF1) of RF switch chip U3. The second terminal of capacitor C29 is connected to the first terminal of resistor R2. The second terminal of resistor R2 is connected to the first terminal of inductor L10. The second terminal of inductor L10 is grounded. The second terminal of resistor R2 is connected to the RF signal receive pin (RFI) of the dual-mode MCU.

[0058] In this circuit, inductors L7, L8, and L11, and capacitors C25, C26, C27, and C28 constitute the wireless transmission matching filter circuit; capacitors C29, C30, and C33 are DC blocking capacitors; capacitors C31 and C32 are the filter capacitors for the two control pins (VC2 and VC1) of the RF switch chip U3 (model RTC6603SP), respectively, to ensure the stability of the switch logic level; resistor R9 is the RF signal tuning resistor, used to fine-tune the matching state at the antenna end; and TVS transistor TVS7 is the wireless signal protection device, used for electrostatic discharge protection.

[0059] Specifically, the RF transmission signal output by the dual-mode MCU undergoes impedance transformation and harmonic suppression via a transmit matched filter network composed of inductors L7, L8, L11 and capacitors C25, C26, C27, and C28 before being sent to the RF2 pin of the RF switch chip U3. Under the logic control of control pins VC1 and VC2, the RF switch chip U3 connects RF2 and RFC, and the signal is output through RFC, then sent to the HRF antenna for outward radiation via DC blocking capacitor C33 and adjustment resistor R9. The weak RF signal received by the HRF antenna enters the RFC terminal of the RF switch chip U3 via resistor R9 and capacitor C33. At this time, the RF switch chip U3 connects RFC and RF1 pins, and the signal is output from RF1. After being processed by the receive matched filter network composed of capacitor C29, resistor R2, and inductor L10, it is sent to the RF signal receiving pin of the dual-mode MCU.

[0060] The zero-crossing detection unit, as a key circuit of the communication module, provides the communication module with an accurate zero-crossing signal. Based on this zero-crossing signal, the communication module can effectively achieve phase identification and topology analysis. In a preferred embodiment, such as... Figure 9 As shown, the zero-crossing detection unit includes resistors R10, R11, R12, R13, and R14, capacitors C34 and C35, and a zero-crossing detection chip U4. The first terminal of resistor R10 and the VSS terminal of the zero-crossing detection chip U4 are both connected to the second terminal of the high-voltage interface unit. The first terminal of resistor R11 is connected to the second terminal of resistor R10, and its second terminal is connected to the first terminal of resistor R12. The second terminal of resistor R12 is connected to the Vin terminal of the zero-crossing detection chip U4. The first terminal of resistor R14 and the second terminal of optocoupler U5 are both connected to the VDD terminal of the zero-crossing detection chip U4, and their second terminals are also connected to the first terminal of optocoupler U5. The second terminal of capacitor C34 is connected to the VSS terminal of the zero-crossing detection chip U4. The first terminal of resistor R13 is connected to the dual-mode MCU, and its second terminal and the third terminal of optocoupler U5 are both connected to the first terminal of capacitor C35. The second terminal of capacitor C35 and the fourth terminal of optocoupler U5 are both grounded. The zero-crossing detection chip U4 is model GS1102, and the optocoupler U5 is model HK816D.

[0061] Specifically, when the input voltage (Vin) of the zero-crossing detection chip U4 is less than the threshold, the optocoupler U5 outputs a zero-crossing signal (ZC_A); when the input voltage is greater than the threshold, the output (VDD) is in a high-impedance state. The zero-crossing detection chip U4 has a static operating current of less than 10μA and extremely low power consumption, allowing most of its electrical energy to be used to drive the optocoupler, thus obtaining a wider zero-crossing detection pulse for easier system detection. Resistor R14 is a charging current-limiting resistor, and capacitor C34 is an energy storage capacitor, together providing power to the zero-crossing detection chip U4 and optocoupler U5. The external voltage divider resistors R10, R11, and R12 can be adjusted according to actual needs. Its working principle is as follows: when Vin > Vth, the optocoupler U5 charges capacitor C34 to VDD voltage for energy storage; when Vin < Vth (i.e., the AC input is near the zero-crossing point), the discharge path from VDD to ground is opened, and the energy stored in capacitor C34 is released through driving optocoupler U5, generating a zero-crossing pulse. Resistor R13 is the secondary pull-up resistor of the optocoupler, and capacitor C35 is the zero-crossing signal filter capacitor, used to prevent the zero-crossing signal from being interfered with.

[0062] Figure 10 The specific structure of the base meter low-voltage interface unit is shown, including a level conversion circuit and an interface protection circuit. The first terminal of the interface protection circuit is connected to the base meter low-voltage interface, and the second terminal is connected to the first terminal of the level conversion circuit. The second terminal of the level conversion circuit is connected to the communication I / O port of the dual-mode MCU. Specifically, when an external interface signal is input through the base meter low-voltage interface, it first enters the interface protection circuit. This interface protection circuit consists of a TVS diode (transient voltage suppressor diode) and an RC network: the TVS diode is connected in parallel between the signal line and ground to absorb transient overvoltage pulses; the RC circuit is connected in series or parallel in the signal path to filter and buffer. Working together, they effectively prevent transient shocks caused by electrostatic discharge and hot-plugging operations from damaging the downstream dual-mode MCU chip, ensuring the safe and reliable operation of the communication module. The signal processed by the interface protection circuit is then sent to the level conversion circuit. This level conversion circuit adjusts the signal level to match the voltage standard of the communication I / O port of the dual-mode MCU chip, thereby achieving reliable communication between different voltage domains.

[0063] To ensure the stable operation of the communication module in complex power environments, the design of the power supply circuit is crucial. This embodiment uses the RY1350 DC-DC power chip U1, which integrates buck / boost / charging functions. Its high integration requires only a few external components to achieve power output, saving on component usage. The power chip employs an ultra-low power design; compared to LDO power supplies, DC-DC power supplies are characterized by high efficiency (over 90%) and low quiescent current, which helps reduce the overall power consumption of the circuit. Specifically, the structure of the power supply unit is as follows... Figure 11As shown, the circuit includes a DC-DC power chip U1, capacitors C1, C2, C3, C4, C5, C6, C7, and C14, resistors R1, R2, R3, and R4, inductor L2, and diode V1. The first terminals of capacitors C1, C2, R1, and V1 are all connected to a 12V power input. The second terminal of resistor R1 is connected to the first terminal of resistor R2. The second terminals of capacitors C1, C2, and R2 are all grounded. The SWU pin of the DC-DC power chip U1 is connected to the second terminal of diode V1, and the SYIN pin is connected to the third terminal of diode V1. The first terminal has the FBU pin connected to the second terminal of resistor R1, the EN pin connected to the common terminal of resistors R3 and R4, the SCAP pin connected to the first terminal of capacitor C7, an inductor L1 connected in series between the SWU pin and the SCAP pin, the OUTD pin serving as the 3.3V power output pin, a capacitor C14 connected in series between the BST pin and the SWD pin, an inductor L2 connected in series between the OUTD pin and the SWD pin, the first terminals of capacitors C3, C4, C5, and C6 all connected to the OUTD pin, and the second terminals all grounded; the first terminal of resistor R3 connected to the 12V power input, and the second terminal connected to the first terminal of resistor R4; the first terminals of resistor R4 and capacitor C7 are both grounded.

[0064] Specifically, the 12V DC power output from the base meter's low-voltage interface unit is converted to a 3.3V operating voltage via a BUCK step-down circuit to power the dual-mode MCU and its interface circuits. Simultaneously, this 12V power also charges the supercapacitor through the charging circuit built into the DC-DC power chip U1. When the mains power fails, the energy stored in the supercapacitor is boosted by the BOOST step-up circuit to enable the reporting of power outage events. In this circuit, capacitors C1 and C2 form the energy storage filter circuit at the power input terminal; resistors R1 and R2 serve as boost feedback resistors to adjust the output voltage of the BOOST circuit; resistors R3 and R4 form an enable voltage divider network to set the output voltage threshold of the power chip; diode V1 is the boost output anti-reverse diode to prevent reverse current; inductor L1 is the boost energy storage inductor for energy storage and freewheeling; capacitor C14 is the bootstrap capacitor of the BUCK circuit; inductor L2 is the energy storage inductor of the BUCK circuit for energy storage and freewheeling; capacitors C3, C4, C5, and C6 are the output filter capacitors of the BUCK circuit to smooth the output voltage; and capacitor C7 is a supercapacitor that provides energy input to the boost circuit after a mains power outage to support the communication module in reporting power outage events.

[0065] To further improve power supply stability, this embodiment uses large-capacity and small-capacity ceramic capacitors to form a π-type filter circuit at the input and output terminals of the DC-DC power supply, respectively, to effectively filter out low-frequency and high-frequency noise in the power supply. Specifically, as shown... Figure 12 As shown, the 12V input power supply filter circuit includes inductor L3, capacitor C12, and capacitor C13. The first terminal of inductor L3 is connected to the 12V voltage input (12VP) of the DC-DC preamplifier, and the second terminal of inductor L3 is connected to the output terminal providing 12V power to the subsequent circuit. Capacitors C12 and C13 are connected in parallel between the 12V node and ground. Capacitor C12 is preferably a 100μF electrolytic capacitor, capacitor C13 is preferably a 0.1μF ceramic capacitor, and the inductance value of inductor L3 is preferably 10uH. This LC filter can effectively suppress low-frequency ripple and high-frequency spurious signals in the power supply. Figure 13 As shown, the 3.3V output filter circuit includes capacitors CP1 and CP2. Capacitors CP1 and CP2 are connected in parallel between the 3.3V power supply output terminal and ground. CP1 is preferably a 22μF ceramic capacitor, and CP2 is preferably a 0.01μF ceramic capacitor, to further improve the purity of the power supply.

[0066] In the power supply circuit design for the carrier analog front-end and wireless analog front-end of the dual-mode MCU, this embodiment also employs targeted filtering measures. Specifically, such as... Figure 14 As shown, the power supply filter circuit for the wireless analog front-end includes a ferrite bead FB1, capacitor C8, and capacitor C9. The first terminal of ferrite bead FB1 is connected to a 3.3V power supply, and the second terminal is connected to the power input terminal (AVDD33_RF) of the wireless analog front-end. Capacitors C8 and C9 are connected in parallel between AVDD33_RF and ground. Capacitor C8 is preferably a 10μF ceramic capacitor, and capacitor C9 is preferably a 0.01μF ceramic capacitor. The output terminal (AVDD33_RF) of this circuit provides a clean power supply to the radio frequency communication unit, thereby reducing phase noise and noise floor, improving the receiving sensitivity and transmission efficiency of the wireless signal, suppressing high-frequency noise, and ensuring the normal operation of the wireless analog front-end. Figure 15As shown, the carrier analog front-end power supply filter circuit includes a ferrite bead FB2, capacitor C10, and capacitor C11. The first terminal of ferrite bead FB2 is connected to a 3.3V power supply, and the second terminal is connected to the power input terminal (AVDD33_AFE) of the carrier analog front-end. Capacitors C10 and C11 are connected in parallel between AVDD33_AFE and ground. Capacitor C10 is preferably a 10μF ceramic capacitor, and capacitor C11 is preferably a 0.01μF ceramic capacitor. The output terminal (AVDD33_AFE) of this filter circuit directly supplies power to the carrier communication unit, effectively filtering out high-frequency noise from different frequency bands and reducing crosstalk between circuits, thereby providing a more stable and clean power supply environment for the analog front-end and ensuring its normal operation. Through the above targeted filtering design, a more stable and clean power supply environment is provided for various circuits of the dual-mode communication module.

[0067] Furthermore, the BeiDou timing unit in this embodiment adopts a master-slave dual-clock source design, with two clock acquisition methods: first, using the received BeiDou satellite clock as the master clock source; second, using the internal crystal oscillator output of the BeiDou timing unit as a backup time source. Simultaneously, this unit is also equipped with an intelligent learning algorithm crystal oscillator training mechanism, used to automatically switch to internal timekeeping mode when the BeiDou signal is lost, ensuring continuous output of highly reliable time information. The working process of the intelligent learning algorithm crystal oscillator training mechanism is as follows: The BeiDou timing unit first acquires a high-precision satellite time signal and compares it with the real-time signal output by the internal crystal oscillator to calculate the frequency deviation. Based on this frequency deviation, the algorithm dynamically adjusts the control voltage and digital capacitor of the crystal oscillator, gradually correcting the output frequency of the crystal oscillator to approximate the standard frequency value of the satellite signal. During this process, the frequency drift, temperature characteristics, and aging patterns of the crystal oscillator are continuously monitored, and key parameters are stored in flash memory. When external satellite signals are lost, the BeiDou module automatically switches to internal timekeeping mode and performs reverse compensation on the crystal oscillator based on the stored parameters, thereby effectively offsetting the frequency shift caused by temperature fluctuations or device aging and maintaining high-precision time output.

[0068] This embodiment integrates the BeiDou timing module into the dual-mode communication module, adding a BeiDou satellite timing channel to provide the module with a high-precision clock data source. This creates a multi-source complementary advantage with existing timing channels, ensuring uninterrupted high-precision clock updates. After synchronizing with the BeiDou system time, the dual-mode communication module can update the electricity meter clock independently or synchronize the time of devices within the local communication network via the dual-mode communication network, achieving high-precision time synchronization across the entire distribution area. The BeiDou timing accuracy can reach the nanosecond level, several orders of magnitude higher than other timing methods. Simultaneously, the BeiDou module's clock employs a master-slave backup design. Through an intelligent learning algorithm and crystal oscillator training mechanism, when the BeiDou signal is normal, the crystal oscillator output is compared with the satellite signal in real time, dynamically correcting frequency deviations. The frequency drift, temperature characteristics, and aging patterns of the crystal oscillator are stored in flash memory. Once the BeiDou signal is lost, the system automatically switches to internal timekeeping mode, performing reverse compensation on the crystal oscillator based on the stored parameters, thereby continuing to provide highly reliable time information. Furthermore, traditional electricity meters typically require replacement of the entire meter when their clocks malfunction, whereas this invention only requires replacing the communication module with time synchronization functionality, significantly reducing maintenance costs. This module conforms to electricity meter interface specifications, is plug-and-play, and is compatible with electricity meters from most manufacturers, making it extremely convenient to use. Leveraging the security, reliability, all-weather capability, and wide signal coverage of the BeiDou Navigation Satellite System, clock synchronization can also be achieved for electricity meters in remote areas, effectively solving the problem of signal blind spots.

[0069] Example 2

[0070] like Figure 16 As shown, this embodiment provides a dual-mode communication system based on BeiDou timing, including a master node (CCO), a proxy node (PCO), and sub-nodes. The sub-nodes include the dual-mode communication module based on BeiDou timing (BeiDou STA) and the ordinary dual-mode communication module (STA) described in Embodiment 1.

[0071] Furthermore, such as Figure 17 As shown, this embodiment also provides a time synchronization method for a dual-mode communication module based on BeiDou time synchronization, including:

[0072] Step S1: The dual-mode communication module parses the perpetual calendar entries from the beacon frames sent by the master node or the agent node, and when the deviation between the perpetual calendar entries and the BeiDou clock exceeds a preset threshold, it sends a time synchronization event message carrying the BeiDou clock and the first network reference time to the master node of the local station area in the CSMA time slot.

[0073] Specifically, such as Figure 16As shown, an electricity meter equipped with a BeiDou time synchronization dual-mode communication module (i.e., BeiDou STA) continuously listens to beacon frames sent by the master node (CCO) or proxy node (PCO) after acquiring BeiDou time, and parses the perpetual calendar entries carried within them. When the sub-node confirms that it has obtained a reliable BeiDou clock, and the deviation between the clock value in the listened perpetual calendar entry and its own BeiDou clock exceeds a preset threshold (i.e., "clock deviation detection" occurs), it triggers a time synchronization event report. Subsequently, the sub-node organizes a time synchronization event report message, which carries the BeiDou clock (i.e., BeiDou time) and the local first network reference time (i.e., NTB value), and sends the message to the master node (CCO) of the local area in a unicast form in the CSMA time slot. The destination address of the message is the CCO of the network.

[0074] In step S2, the master node synchronizes its time with the BeiDou clock and the first network reference time, and sends a beacon message carrying the calibrated second real-time clock and the second network reference time to the master node's child nodes in the beacon time slot.

[0075] Specifically, after receiving the time synchronization event message reported by the child node, the CCO first replies with a confirmation frame, then parses the BeiDou clock and the first network reference time carried in the message. The CCO calibrates its own real-time clock (RTC) according to the time synchronization algorithm to obtain the calibrated second real-time clock, and synchronously generates the corresponding second network reference time (NTB value). After calibration, the CCO sends a beacon message carrying the second real-time clock and the second network reference time to all its subordinate child nodes (including BeiDou STAs, STAs, and PCOs) in the beacon time slot. Figure 16 The entire network is synchronized with the time.

[0076] like Figure 18 As shown, when a time synchronization message is transmitted in a dual-mode communication system, it is affected by factors such as transmission channel delay, analog device delay, digital processing delay, transmission / reception jitter, and multi-level forwarding. Furthermore, the message's timeliness is compromised due to the multi-level network forwarding and retransmission process, increasing the difficulty of accurate time synchronization. Assume the sending end (e.g., a child node) encapsulates its local RTC and NTB count values ​​in a time synchronization message at local time T1 and sends it; the receiving end (e.g., the CCO) parses the clock count value from the message at time T2. The total message transmission delay is... It can be represented as:

[0077] (1)

[0078] In the formula, Transmission delay jitter, including analog / digital processing delay and jitter, is relatively fixed at approximately 50μs to 100μs. DEC is the time required for the receiver to parse the message, which depends on the message length and TMI mode; according to the dual-mode protocol specification, its parsing time should be less than 400μs. The receiver uses the above algorithm to accurately estimate the total delay and calibrate its own RTC, achieving an estimation accuracy better than 500μs. For a typical electricity information acquisition system with no more than 5 levels, even in the worst-case scenario where errors from each level are superimposed in the same direction, the overall time synchronization accuracy can still be controlled within 2ms.

[0079] Step S3: The child node synchronizes its time according to the second real-time clock and the second network reference time.

[0080] Specifically, after each sub-node (STA or PCO) receives the beacon message sent by the CCO, it parses out the CCO's second real-time clock and second network reference time in the message, performs time synchronization calculations with its own RTC time and NTB value, and forwards the time synchronization result to the connected electricity meter to complete the accurate time synchronization.

[0081] This embodiment actively monitors the deviation between the perpetual calendar entries in the beacon frame and its own BeiDou clock using a dual-mode communication module equipped with a BeiDou timing unit. When the deviation exceeds the limit, a time synchronization event is triggered and reported, achieving a rapid detection and proactive reporting mechanism for clock anomalies and avoiding the communication overhead caused by periodic polling across the entire network. The master node (CCO) synchronizes its time with the BeiDou clock reported by the child nodes and the Network Reference Time (NTB), then broadcasts the calibrated time to all child nodes using the beacon time slot, enabling each level of node to achieve step-by-step synchronization based on BeiDou high-precision time. Combined with... Figure 17 The latency estimation algorithm shown separates the transmission latency jitter (approximately 50μs to 100μs) from the message parsing time (less than 400μs) in its calculation, achieving a time synchronization accuracy better than 500μs. Even in typical electricity consumption information collection systems not exceeding level 5, the overall time synchronization accuracy can still be controlled within 2ms in the worst-case scenario, far superior to the second- or millisecond-level time synchronization accuracy of traditional electricity meters. Furthermore, this method fully utilizes the beacon frames and CSMA time slot resources of dual-mode communication networks without requiring additional communication overhead. It boasts advantages such as simple implementation, strong compatibility, and plug-and-play functionality. It effectively solves the clock inaccuracy problem caused by signal blind spots or clock drift in electricity meters in remote areas, reducing maintenance costs and improving the reliability and redundancy of time synchronization across the entire distribution area.

[0082] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A dual-mode communication module based on BeiDou timing, characterized in that, The dual-mode communication module includes a base meter low-voltage interface unit, a Beidou time synchronization unit, a carrier communication unit, a radio frequency communication unit, a high-voltage interface unit, a zero-crossing detection unit, a dual-mode MCU, and a power supply unit; The first end of the power supply unit and the first end of the carrier communication unit are connected to the first end of the base meter weak current interface unit. The second end of the power supply unit is connected to the power input terminal of the dual-mode MCU. The second end of the base meter weak current interface is connected to the communication I / O port of the dual-mode MCU. The second end of the carrier communication unit is connected to the carrier communication port of the dual-mode MCU. The third end is connected to the first end of the high current interface unit. The first end of the zero-crossing detection unit is connected to the second end of the high current interface unit. The second end is connected to the zero-crossing signal receiving port of the dual-mode MCU. The first end of the radio frequency communication unit is connected to the radio frequency communication port of the dual-mode MCU. The second end is connected to the HRF antenna. The first end of the Beidou timing unit is connected to the Beidou communication port of the dual-mode MCU. The second end is connected to the Beidou antenna.

2. The dual-mode communication module based on BeiDou timing according to claim 1, characterized in that, The BeiDou timing unit includes a BeiDou timing chip, a decoupling circuit, an RC filter circuit, a BeiDou signal output matching circuit, a BeiDou antenna interface circuit, and a filter matching circuit. The first terminal of the decoupling circuit is connected to a 3.3V voltage input, and the second terminal is connected to the main power input pin of the BeiDou timing chip. The first terminal of the RC filter circuit is connected to the dual-mode MCU, and the second terminal is connected to the external reset signal receiving pin of the BeiDou timing chip. The first terminal of the BeiDou signal output matching circuit is connected to the BeiDou antenna interface circuit, and the second terminal is connected to the antenna input pin of the BeiDou timing chip. The first terminal of the filter matching circuit is connected to the first terminal of the BeiDou signal output matching circuit, and the second terminal is connected to the BeiDou antenna power supply pin of the BeiDou timing chip.

3. The dual-mode communication module based on BeiDou timing according to claim 1, characterized in that, The carrier communication unit includes a carrier transmitting circuit, a carrier receiving circuit, and a carrier coupling circuit. The carrier communication port includes a carrier signal transmitting end and a carrier signal receiving end. The first end of the carrier transmitting circuit is connected to the carrier signal transmitting end, and the second end is connected to the first end of the carrier coupling circuit. The second end of the carrier coupling circuit is connected to the first end of the carrier receiving circuit, and the third end is connected to the high-voltage interface unit. The second end of the carrier receiving circuit is connected to the carrier signal receiving end.

4. The dual-mode communication module based on BeiDou timing according to claim 3, characterized in that, The carrier transmission circuit includes a carrier PA chip U2, resistors Re, Rf, Rg, R5, R6, capacitors C15, C16, C17, C18, C19, TVS transistors TVS1 and TVS2; the first end of capacitor C15 is connected to the non-inverting input of the carrier signal transmission pin of the dual-mode MCU, and the second end is connected to the A-channel non-inverting analog signal input pin of the carrier PA chip U2; the first end of capacitor C16 is connected to the inverting input of the carrier signal transmission pin of the dual-mode MCU, and the second end is connected to the B-channel non-inverting analog signal input pin of the carrier PA chip U2; the first ends of resistors Re and R5 are both connected to the A-channel signal output pin of the carrier PA chip U2; the first end of resistor R5... The first terminal of both the two-terminal resistor and the first terminal of the TVS transistor TVS2 are connected to the first terminal of capacitor C18; the second terminal of capacitor C18 is the non-inverting transmission port of the carrier transmission channel; the second terminal of resistor Re and the first terminal of capacitor C17 are both connected to the inverting analog signal input pin of channel A of carrier PA chip U2; the second terminal of capacitor C17 is connected to the first terminal of resistor Rg; the second terminal of resistor Rg and the first terminal of resistor Rf are both connected to the inverting analog signal input pin of channel B of carrier PA chip U2; the second terminal of resistor Rf and the first terminal of resistor R6 are both connected to the signal output pin of channel B of carrier PA chip U2; the second terminal of resistor R6 and the first terminal of TVS transistor TVS1 are both connected to the first terminal of capacitor C19; the second terminal of capacitor C19 is the inverting transmission port of the carrier transmission channel; the second terminals of TVS transistors TVS1 and TVS2 are both grounded.

5. The dual-mode communication module based on BeiDou timing according to claim 3, characterized in that, The carrier receiving circuit includes resistors R7 and R8, capacitors C20, C21, C22, C23, and C24, inductors L4, L5, and L6, and TVS transistors TVS3 and TVS4. The first terminal of resistor R7 is connected to the non-inverting receiving port of the carrier receiving channel, and the second terminal is connected to the first terminal of capacitor C20. The second terminal of capacitor C20 is connected to the first terminal of capacitor C22. The second terminal of capacitor C22 is connected to the first terminal of inductor L5. The second terminal of inductor L5 is connected to the first terminal of TVS transistor TVS3. The first terminal of resistor R8 is connected to the inverting receiving port of the carrier receiving channel, and the second terminal is connected to capacitor C21. The first terminal of capacitor C21 is connected to the first terminal of capacitor C23; the second terminal of capacitor C23 is connected to the first terminal of inductor L6; the second terminal of inductor L6 is connected to the first terminal of TVS transistor TVS4; the second terminals of TVS transistors TVS3 and TVS4 are both grounded; the first terminal of inductor L4 is connected to the second terminal of capacitor C20, and the second terminal is connected to the second terminal of capacitor C21; the first terminal of capacitor C24 is connected to the second terminal of inductor L5, and the second terminal is connected to the second terminal of inductor L6; the second terminal of inductor L5 is connected to the inverting input of the carrier signal receiving pin of the dual-mode MCU, and the second terminal of inductor L6 is connected to the non-inverting input of the carrier signal receiving pin of the dual-mode MCU.

6. The dual-mode communication module based on BeiDou timing according to claim 3, characterized in that, The carrier coupling circuit includes a coupling transformer T1, a safety capacitor Cx1, a TVS diode TVS5, and a TVS diode TVS6. The first end of the coupling transformer T1 is connected to the carrier transceiver channel, and the second end is connected to the high-voltage interface unit. The safety capacitor Cx1 is connected in series in the coil circuit of the second end of the coupling transformer T1. The TVS diode TVS5 is connected in parallel across the coil of the first end of the coupling transformer T1, and the TVS diode TVS6 is connected in parallel across the coil of the second end of the coupling transformer T1.

7. The dual-mode communication module based on BeiDou timing according to claim 1, characterized in that, The radio frequency communication unit includes a radio frequency matching circuit and a radio frequency switch. The first end of the radio frequency matching circuit is connected to the radio frequency communication port, and the second end is connected to the first end of the radio frequency switch. The second end of the radio frequency switch is connected to the HRF antenna.

8. The dual-mode communication module based on BeiDou timing according to claim 1, characterized in that, The base meter low-voltage interface unit includes a level conversion circuit and an interface protection circuit; the first end of the interface protection circuit is connected to the base meter low-voltage interface, and the second end is connected to the first end of the level conversion circuit; the second end of the level conversion circuit is connected to the communication I / O port of the dual-mode MCU.

9. A dual-mode communication system based on BeiDou timing, characterized in that, The system includes a master node, a proxy node, and a sub-node, wherein the sub-node includes a dual-mode communication module based on BeiDou timing as described in any one of claims 1-9.

10. A time synchronization method for a dual-mode communication module based on BeiDou time synchronization, characterized in that, The method is applied to the dual-mode communication system based on BeiDou timing as described in claim 9, and the method includes: Step S1: The dual-mode communication module parses the perpetual calendar entry from the beacon frame sent by the master node or the proxy node, and when the deviation between the perpetual calendar entry and the BeiDou clock exceeds a preset threshold, it sends a time synchronization event message carrying the BeiDou clock and the first network reference time to the master node of the local station area in the CSMA time slot. Step S2: The master node synchronizes its time with the BeiDou clock and the first network reference time, and sends a beacon message carrying the calibrated second real-time clock and the second network reference time to the master node's sub-nodes in the beacon time slot; Step S3: The child node synchronizes its time according to the second real-time clock and the second network reference time.

Images