Direct current magnetic bias monitoring device based on Beidou second pulse synchronization

Abstract

The invention relates to a direct-current magnetic bias monitoring device based on Beidou second pulse synchronization. The direct-current magnetic bias monitoring device comprises a Beidou time service unit, a current monitoring unit and a control execution unit, the Beidou time service unit receives a satellite signal and processes the satellite signal to generate an ADC sampling trigger signal; the current monitoring unit monitors and collects a current signal, conditions the current signal, and starts conversion at the rising edge of an ADC sampling trigger signal to realize synchronous sampling; and the control execution unit processes the current data acquired by the current monitoring unit in real time and performs calculation, outputs a dual-mode decision control signal according to a calculation result, and executes corresponding operation according to the dual-mode decision control signal. According to the invention, sampling is triggered through direct connection of Beidou second pulse hardware, synchronization errors of software time service in a traditional scheme can be thoroughly eliminated, and strict time alignment of measurement points of the whole network is ensured; the action delay is greatly shortened; invalid switching times can be obviously reduced, and the service life of the device is prolonged.

Description

Technical Field

[0001] This invention relates to the technical field of power system safety monitoring, and more specifically, to a DC bias monitoring device based on BeiDou second pulse synchronization. Background Technology

[0002] Under the UHVDC unipolar-earth loop operation mode, the DC current injected into the grounding electrode propagates through the soil, causing an increase in the ground potential of the AC substations around the grounding electrode. This results in DC bias magnetization of the AC transformer within a certain range around the grounding electrode. The DC current flowing through the transformer neutral point is affected by various factors, including the shape of the grounding electrode, the magnitude of the grounding current, soil resistivity, topography, underground metal components (such as heating, drainage, oil or gas pipelines), substation grounding resistance, transformer equivalent DC resistance, AC system network topology, and AC network DC resistance parameters. Currently, simulation methods show a significant impact of soil models on DC bias magnetization. Given the wide-area variability of soil conditions, the complexity of AC / DC networks, and unavoidable errors in data and simulation calculations, the calculated results are likely to deviate considerably from the measured results.

[0003] The selection of DC bias suppression measures is crucial in actual measurements. Due to the wide distribution of DC lines and the presence of numerous directly grounded AC devices around the DC poles, adjustments to different DC line operating modes are necessary. Therefore, measurements typically require significant manpower and resources for coordination. Furthermore, current actual measurement methods are limited, generally conducted only under fixed weather conditions, and the measurement area is defined based on previous simulation results, sometimes resulting in completely contradictory simulation data. The measured data is insufficient to comprehensively assess the influence of DC current bias on the entire AC equipment, hindering effective calibration of the simulation model. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a DC bias monitoring device based on Beidou second pulse synchronization, which addresses the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a DC bias monitoring device based on Beidou second pulse synchronization, including: a Beidou time synchronization unit, a current monitoring unit connected to the Beidou time synchronization unit, and a control execution unit connected to the current monitoring unit;

[0006] The BeiDou timing unit is used to receive satellite signals and process the satellite signals to generate an ADC sampling trigger signal;

[0007] The current monitoring unit is used to monitor and acquire current signals and condition the current signals, and to achieve synchronous sampling by starting the conversion at the rising edge of the ADC sampling trigger signal;

[0008] The control execution unit is used to process the current data collected by the current monitoring unit in real time and perform calculations, output a dual-mode decision control signal based on the calculation results, and perform corresponding operations based on the dual-mode decision control signal.

[0009] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the BeiDou timing unit includes: a BeiDou antenna, a timing module, and a synchronization control module;

[0010] The Beidou antenna is used to receive the satellite signals and generate corresponding radio frequency signals based on the satellite signals.

[0011] The timing module is connected to the Beidou antenna and is used to analyze the radio frequency signal and generate a 1PPS pulse signal.

[0012] The synchronization control module is connected to the timing module and the current monitoring unit, and is used to convert the 1PPS pulse signal into the ADC sampling trigger signal.

[0013] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the timing module adopts a structure of BeiDou dual-mode timing chip and temperature-compensated crystal oscillator.

[0014] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the synchronization control module monitors the 1PPS pulse signal in real time and initiates signal conversion when the rising edge of the 1PPS pulse signal arrives to convert the 1PPS pulse signal into the ADC acquisition trigger signal.

[0015] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the current monitoring unit includes: a current monitoring module, a signal conditioning module, and an analog-to-digital conversion module;

[0016] The current monitoring module is used to monitor and acquire the current signal;

[0017] The signal conditioning module is used to condition the current signal;

[0018] The analog-to-digital conversion module is used to perform analog-to-digital conversion on the current signal at the rising edge of the ADC sampling trigger signal to obtain the current data.

[0019] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the current monitoring module includes a current sensor, which is a zero-flux DC current sensor.

[0020] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the analog-to-digital conversion module includes an ADC converter, which is a 24-bit Σ-Δ analog-to-digital converter.

[0021] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the signal conditioning module includes: a power frequency notch filter circuit, a DC low-pass filter circuit, and a level shifting circuit.

[0022] The power frequency notch processing circuit is connected to the current monitoring module and is used to perform power frequency notch processing on the current signal.

[0023] The DC low-pass processing circuit is connected to the power frequency notch processing circuit and is used to perform DC low-pass processing on the current signal that has completed power frequency processing.

[0024] The level shifting circuit is connected to the DC low-pass processing circuit and is used to shift the level of the current signal after the DC low-pass processing is completed.

[0025] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the control execution unit includes: a main control module, a communication module, a central server, a drive circuit, and a local suppression device;

[0026] The central server is connected to the main control module through the communication module, the main control module is connected to the analog-to-digital conversion module, and the local suppression device is connected to the main control module through the drive circuit;

[0027] The main control module is used to process the current data collected by the analog-to-digital conversion module in real time and perform calculations, and output the dual-mode decision control signal according to the calculation results; the dual-mode decision control signal includes: cooperative mode control signal and local mode control signal;

[0028] The communication module is used to perform communication between the main control module and the central server;

[0029] The central server is used to analyze the biased magnetic propagation direction based on the network-wide synchronous data stream according to the cooperative mode control signal and generate target cooperative instructions according to the biased magnetic propagation direction.

[0030] The driving circuit is used to generate a driving signal to the local suppression device according to the local mode control signal;

[0031] The local suppression device performs a local switching operation based on the drive signal.

[0032] In the DC bias monitoring device based on BeiDou second pulse synchronization described in this invention, the communication module includes a main channel and a backup channel; the main channel and the backup channel are designed in a redundant manner, and the main channel is a 4G / 5G wireless network; the backup channel is an optical fiber Ethernet.

[0033] The DC bias monitoring device based on BeiDou second pulse synchronization of the present invention has the following beneficial effects: The present invention completely eliminates the synchronization error of software time synchronization in traditional schemes by directly triggering sampling through hardware connection of BeiDou second pulse, ensuring strict time alignment of measurement points across the entire network; based on the propagation direction identification capability of synchronous data stream, it supports the predictive activation of suppression devices at downstream stations, significantly shortening the action delay; the central coordination strategy only triggers the action of bias source stations, significantly reducing the number of invalid switching operations and extending the device lifespan; the high anti-interference signal conditioning design accurately extracts weak DC components under strong power frequency interference; multiple redundancy mechanisms (time-keeping crystal oscillator / local strategy) ensure reliability under extreme operating conditions; the calibration-free circuit design reduces on-site calibration steps, and the modular architecture improves maintenance convenience. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of the DC bias monitoring device based on BeiDou second pulse synchronization provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the method for implementing synchronous control provided by the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This invention solves the industry problem of "inaccurate measurement and slow control" in DC bias control by employing two core technologies: BeiDou second-pulse hardware triggering and network-wide collaborative suppression, and has broad market prospects. Furthermore, the DC bias monitoring device based on BeiDou second-pulse synchronization can be applied in the power industry, such as nuclear power plants and substations, improving the operation and maintenance safety of isolation devices and significantly enhancing the economic and safety benefits for enterprises.

[0039] In a preferred embodiment, such as Figure 1 As shown, the DC bias monitoring device based on BeiDou second pulse synchronization includes: a BeiDou timing unit 100, a current monitoring unit 200 connected to the BeiDou timing unit 100, and a control execution unit 300 connected to the current monitoring unit 200. The BeiDou timing unit 100 is used to receive satellite signals and process them to generate an ADC sampling trigger signal.

[0040] In this embodiment of the invention, the current monitoring unit 200 is used to monitor and acquire current signals and condition the current signals, and to start the conversion at the rising edge of the ADC sampling trigger signal to achieve synchronous sampling.

[0041] Optionally, in some embodiments, the BeiDou timing unit 100 includes: a BeiDou antenna 101, a timing module 102, and a synchronization control module 103; the BeiDou antenna 101 is used to receive satellite signals and generate corresponding radio frequency signals based on the satellite signals; the timing module 102 is connected to the BeiDou antenna 101 and is used to parse the radio frequency signals to generate a 1PPS pulse signal; the synchronization control module 103 is connected to the timing module 102 and the current monitoring unit 200 and is used to convert the 1PPS pulse signal into an ADC sampling trigger signal. Preferably, in this embodiment of the invention, the timing module 102 adopts a structure of a BeiDou dual-mode timing chip (such as the HeXin XingTong UB380) and a temperature-compensated crystal oscillator. The synchronization control module 103 monitors the 1PPS pulse signal in real time and initiates signal conversion when the rising edge of the 1PPS pulse signal arrives to convert the 1PPS pulse signal into an ADC acquisition trigger signal.

[0042] Specifically, the Beidou antenna 101 receives satellite signals (L-band) and outputs radio frequency signals to the timing module 102; the timing module 102 analyzes the radio frequency signals to obtain the satellite signals, and generates a 1PPS pulse signal based on the satellite signals to output an RS232 time message (year / month / day / hour / minute / second); the synchronization control module 103 converts the 1PPS pulse signal into an ADC sampling trigger signal, and generates an equally spaced sampling clock (e.g., 10Hz) in steps through the FPGA.

[0043] refer to Figure 2 , Figure 2 The core working principle of the FPGA-based synchronous sampling control module of this invention is illustrated. For example... Figure 2As shown, the rising edge of the 1PPS pulse transmitted by the BeiDou satellite, serving as the absolute time reference for the entire system, represents the starting point of the UTC microsecond. This rising edge signal is directly input to the dedicated clock pin of the FPGA. Upon detecting the 1PPS rising edge, the FPGA immediately performs the following operations: directly pulls the ADC converter's start conversion (CONVST) signal high via hardware connection; and sends an interrupt signal to the main control module 301 to mark the "integer second sampling point." This process is entirely implemented by hardware logic, avoiding the millisecond-level delay of software processing. After receiving the rising edge of the CONVST signal, the ADC converter will complete three key actions within a fixed time window: reset the internal sample-and-hold circuit; initiate the analog signal to digital conversion; and latch the first sampling point data. This design ensures that all stations across the network initiate their first sampling at the same UTC microsecond. After the initial sampling is completed, the frequency divider counter inside the FPGA immediately starts working: its base clock source is a 10MHz high-frequency clock output from a temperature-compensated crystal oscillator (TCXO), and the frequency division parameters are dynamically configured according to the preset sampling rate; when the cumulative value of the frequency divider reaches the preset threshold, a subsequent sampling pulse that meets the conversion timing requirements of the ADC converter is generated. At the same time, each BeiDou 1PPS rising edge will synchronously reset the frequency divider counters of all stations, completely eliminating the clock accumulation error and ensuring the long-term synchronization of subsequent sampling times across the entire network.

[0044] In this embodiment of the invention, the current monitoring unit 200 is used to monitor and acquire current signals and condition the current signals, and to start the conversion at the rising edge of the ADC sampling trigger signal to achieve synchronous sampling.

[0045] Optionally, in some embodiments, the current monitoring unit 200 includes: a current monitoring module 201, a signal conditioning module 202, and an analog-to-digital conversion module 203. The current monitoring module 201 is used to monitor and acquire current signals; the signal conditioning module 202 is used to condition the current signals; and the analog-to-digital conversion module 203 is used to perform analog-to-digital conversion on the current signals at the rising edge of the ADC sampling trigger signal to obtain current data. Preferably, the current monitoring module 201 includes a current sensor. The current sensor used in this invention is preferably a zero-flux DC current sensor. In this embodiment, the analog-to-digital conversion module 203 includes: an ADC converter. Preferably, the ADC converter is a 24-bit Σ-Δ analog-to-digital converter (such as an ADS1256).

[0046] Optionally, in some embodiments, the signal conditioning module 202 includes: a power frequency notch filtering circuit, a DC low-pass filtering circuit, and a level shifting circuit; the power frequency notch filtering circuit is connected to the current monitoring module 201 and is used to perform power frequency notch filtering on the current signal; the DC low-pass filtering circuit is connected to the power frequency notch filtering circuit and is used to perform DC low-pass filtering on the current signal that has completed power frequency processing; the level shifting circuit is connected to the DC low-pass filtering circuit and is used to perform level shifting on the current signal that has completed DC low-pass processing.

[0047] Specifically, the current sensor can be installed on the neutral point grounding wire of the transformer to achieve real-time monitoring and acquisition of the current signal. The signal processing module adopts a three-stage processing approach: power frequency notch filtering, DC low-pass filtering, and level shifting. The processing steps are as follows: first, power frequency notch filtering is performed to eliminate the strong power frequency component in the transformer neutral point current to prevent ADC saturation; second, DC low-pass filtering is performed to extract the pure DC component; and finally, level shifting is performed to adapt to the 0-3.3V ADC converter. The ADC converter uses a 24-bit Σ-Δ analog-to-digital converter, and it initiates conversion on the rising edge of the trigger signal to achieve synchronous sampling.

[0048] In this embodiment of the invention, the control execution unit 300 is used to process the current data collected by the current monitoring unit 200 in real time and perform calculations, and output a dual-mode decision control signal according to the calculation results, and perform corresponding operations according to the dual-mode decision control signal.

[0049] Optionally, in some embodiments, the control execution unit 300 includes: a main control module 301, a communication module 302, a central server 303, a drive circuit 304, and a local suppression device 305. The central server 303 is connected to the main control module 301 via the communication module 302. The main control module 301 is connected to the analog-to-digital converter module 203. The local suppression device 305 is connected to the main control module 301 via the drive circuit 304. The main control module 301 is used to process the current data collected by the analog-to-digital converter module 203 in real time, perform calculations, and output dual-mode decision control signals based on the calculation results. The dual-mode decision control signals include a cooperative mode control signal and a local mode control signal. The communication module 302 is used to perform communication between the main control module 301 and the central server 303. The central server 303 is used to analyze the bias propagation direction based on the network-wide synchronous data stream according to the cooperative mode control signal and generate target cooperative instructions based on the bias propagation direction. The drive circuit 304 is used to generate drive signals to the local suppression device 305 according to the local mode control signal. The local suppression device 305 performs local switching operations according to the drive signals. Preferably, the communication module 302 includes a main channel and a backup channel. The main channel and the backup channel are designed in a redundant manner, and the main channel is a 4G / 5G wireless network; the backup channel is a fiber optic Ethernet. Preferably, the drive circuit 304 uses optocoupler isolation and IGBT / thyristor gate drive chips.

[0050] Specifically, the control execution unit 300 is the decision-making and response part of the entire system. It consists of a main control module 301, a communication module 302, a central server 303, a drive circuit 304, and a local suppression device 305, forming a closed-loop system. The main control module 301 primarily processes the current data collected by the ADC converter in real time, calculates the effective value and rate of change (calculation results) based on the current data, and then outputs corresponding dual-mode decision control signals according to the effective value and rate of change. When the output is a local mode control signal, the drive circuit 304 generates a corresponding drive signal to directly trigger the local suppression device 305. The local suppression device 305 (capacitor DC blocking / dynamic resistor, etc.) performs a switching operation after receiving the drive signal. When the output is a cooperative mode control signal, the communication module 302 uploads data with a UTC timestamp to the central server 303. The central server 303 analyzes the bias propagation direction based on the network-wide synchronous data stream and generates target cooperative instructions to be sent to each station.

[0051] In this embodiment of the invention, the effective value and the rate of change can be calculated using the following formula:

[0052] Valid values:

[0053]

[0054] Rate of change:

[0055]

[0056] In equations (1) and (2), I k Let be the current value at the k-th sampling point, N be the total number of sampling points within the window, and Δt be the sampling period.

[0057] The specific process for dual-mode decision-making is as follows:

[0058] When the rate of change Or effective value I eff When the local threshold is exceeded, the main control module 301 (MCU) directly outputs the local mode control signal, which drives the local suppression device 305 to operate through the drive circuit 304.

[0059] When no local threshold is triggered and the rate of change Or effective value I eff When the collaborative threshold is exceeded (based on actual settings), the sampled data with UTC timestamps is uploaded to the central server 303 via the dual-channel redundant communication module 302 for network-wide collaborative analysis.

[0060] In this embodiment of the invention, the bias propagation direction of the central server 303 is analyzed as follows:

[0061] First, the synchronous sampling timestamps and effective value change sequences of each monitoring point were collected, as shown in Table 1.

[0062] Table 1

[0063]

[0064]

[0065] As shown in Table 1, the sampling timestamps of all monitoring points are completely consistent, reflecting the synchronization characteristics triggered by the BeiDou 1PPS hardware. The upward trend of the ΔA value over time shows that monitoring point A shows a significant increase first, followed by points B, C, and D, with an increase time difference of approximately 0.2–0.4 s, which can be used to infer the propagation direction.

[0066] Next, using the time difference (Δ) t The maximum correlation between the amplitude increment and the bias signal is used to determine the relationship before and after the propagation of the bias signal. Specifically:

[0067] ΔA=I err -I B (3);

[0068] (3) In the formula, ΔA is the amplitude increment, I B It is the average current.

[0069] Among them, time difference (Δt The maximum correlation between the magnitude increment and the amplitude increment was determined by the following method:

[0070] The cross-correlation function between sites i and j is:

[0071]

[0072] The estimated arrival time difference between i and j is:

[0073] Δt ij =τ ij / f s (6);

[0074] If Δt ij If <0, then site i is ahead of site j.

[0075] Then, the primary source (the site where the most severe magnetic bias first appeared) and the downstream propagation path were determined. Specifically:

[0076] By comparing multiple sites pairwise and counting the number of times they lead, the primary source can be determined.

[0077] The earliest arrival point s is selected as the candidate source, and then other stations are considered with Δt = t. i -t s0 Δt=t i The paths are sorted to obtain the paths, and finally, cross-correlation is used to estimate Δt. s0 i verifies that the sorting is consistent.

[0078] Finally, generate the target coordination instructions.

[0079] The target coordination instruction is to trigger only the bias source site or a few sites on the critical path, reducing unnecessary switching and shortening response latency, specifying which site, which suppression device, and when to activate. Its specific generation logic is as follows:

[0080] 1. Identify the primary source S (earliest rising or most correlated).

[0081] 2. Mark key nodes based on the propagation path (e.g., consecutive stations with an arrival time difference of less than a threshold constitute the critical path).

[0082] 3. Select the suppression action set: Select the "action priority" (0 = no action, 1 = time-limited capacitor switching, 2 = access dynamic resistor, etc.) for each critical site, and minimize the number of switching operations and the overall response time of the entire network by combining equipment capabilities and topology constraints.

[0083] 4. The central server 303 outputs the target coordination instruction sequence and adjusts it based on feedback.

[0084] The following example illustrates this:

[0085] Table 2. Related Operations and Information for Generating Target Coordination Instructions

[0086]

[0087] As can be seen from point 2, priority is given to rapid switching at source station A. Since A arrives earliest and has the largest ΔA, the suppression effect of switching is the best. For B, delayed observation (not immediate switching) is adopted to avoid chain switching and unnecessary transients. If A switches successfully (ΔA decreases by ≥50% within 200ms), the subsequent actions of B / C are canceled; if A switches unsuccessfully or communication is lost, a forced action is automatically issued locally or centrally according to the preset fallback strategy.

[0088] This invention utilizes direct hardware-triggered sampling via BeiDou second pulses to completely eliminate synchronization errors caused by software timing in traditional solutions, ensuring strict time alignment across all measurement points in the network. Based on the propagation direction recognition capability of the synchronous data stream, it supports the predictive activation of suppression devices at downstream stations, significantly reducing action delays. The central coordination strategy triggers only the bias source station, significantly reducing invalid switching and extending device lifespan. A high-interference-resistant signal conditioning design accurately extracts weak DC components even under strong power frequency interference. Multiple redundancy mechanisms (time-keeping crystal oscillator / local strategy) ensure reliability under extreme operating conditions. The calibration-free circuit design reduces on-site calibration steps, and the modular architecture improves maintenance convenience.

[0089] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0090] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0091] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0092] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A DC bias monitoring device based on BeiDou second pulse synchronization, characterized in that, include: The system includes a BeiDou timing unit, a current monitoring unit connected to the BeiDou timing unit, and a control execution unit connected to the current monitoring unit. The BeiDou timing unit is used to receive satellite signals and process the satellite signals to generate an ADC sampling trigger signal; The current monitoring unit is used to monitor and acquire current signals and condition the current signals, and to achieve synchronous sampling by starting the conversion at the rising edge of the ADC sampling trigger signal; The control execution unit is used to process the current data collected by the current monitoring unit in real time and perform calculations, output a dual-mode decision control signal based on the calculation results, and perform corresponding operations based on the dual-mode decision control signal.

2. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 1, characterized in that, The BeiDou timing unit includes: a BeiDou antenna, a timing module, and a synchronization control module; The Beidou antenna is used to receive the satellite signals and generate corresponding radio frequency signals based on the satellite signals. The timing module is connected to the Beidou antenna and is used to analyze the radio frequency signal and generate a 1PPS pulse signal. The synchronization control module is connected to the timing module and the current monitoring unit, and is used to convert the 1PPS pulse signal into the ADC sampling trigger signal.

3. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 2, characterized in that, The timing module adopts a structure of Beidou dual-mode timing chip and temperature-compensated crystal oscillator.

4. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 2, characterized in that, The synchronization control module monitors the 1PPS pulse signal in real time and initiates signal conversion when the rising edge of the 1PPS pulse signal arrives to convert the 1PPS pulse signal into the ADC acquisition trigger signal.

5. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 2, characterized in that, The current monitoring unit includes: a current monitoring module, a signal conditioning module, and an analog-to-digital conversion module; The current monitoring module is used to monitor and acquire the current signal; The signal conditioning module is used to condition the current signal; The analog-to-digital conversion module is used to perform analog-to-digital conversion on the current signal at the rising edge of the ADC sampling trigger signal to obtain the current data.

6. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 5, characterized in that, The current monitoring module includes a current sensor, which is a zero-flux DC current sensor.

7. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 5, characterized in that, The analog-to-digital conversion module includes an ADC converter, which is a 24-bit Σ-Δ analog-to-digital converter.

8. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 5, characterized in that, The signal conditioning module includes: a power frequency notch filter circuit, a DC low-pass filter circuit, and a level shifting circuit. The power frequency notch processing circuit is connected to the current monitoring module and is used to perform power frequency notch processing on the current signal. The DC low-pass processing circuit is connected to the power frequency notch processing circuit and is used to perform DC low-pass processing on the current signal that has completed power frequency processing. The level shifting circuit is connected to the DC low-pass processing circuit and is used to shift the level of the current signal after the DC low-pass processing is completed.

9. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 5, characterized in that, The control execution unit includes: a main control module, a communication module, a central server, a drive circuit, and a local suppression device; The central server is connected to the main control module through the communication module, the main control module is connected to the analog-to-digital conversion module, and the local suppression device is connected to the main control module through the drive circuit; The main control module is used to process the current data collected by the analog-to-digital conversion module in real time and perform calculations, and output the dual-mode decision control signal according to the calculation results; the dual-mode decision control signal includes: cooperative mode control signal and local mode control signal; The communication module is used to perform communication between the main control module and the central server; The central server is used to analyze the biased magnetic propagation direction based on the network-wide synchronous data stream according to the cooperative mode control signal and generate target cooperative instructions according to the biased magnetic propagation direction. The driving circuit is used to generate a driving signal to the local suppression device according to the local mode control signal; The local suppression device performs a local switching operation based on the drive signal.

10. The DC bias monitoring device based on BeiDou second pulse synchronization according to claim 9, characterized in that, The communication module includes a main channel and a backup channel; the main channel and the backup channel are designed for redundancy, and the main channel is a 4G / 5G wireless network; the backup channel is a fiber optic Ethernet.

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