A traceability network system consisting of multi quantum current transformers

Abstract

This invention discloses a traceability network system composed of multiple quantum current transformers, relating to the field of quantum metrology. It includes: multiple quantum current transformers, each integrating a time-frequency transmission device. This time-frequency transmission device receives external timing signals and performs bidirectional transmission of time-frequency references between the time-frequency transmission devices of other quantum current transformers. The multiple quantum current transformers are interconnected through the time-frequency transmission devices to construct a multi-node traceability network. A control system is communicatively connected to each quantum current transformer. Based on the bidirectional transmission of external timing signals and inter-device time-frequency references, a unified time-frequency reference is distributed to each quantum current transformer, and measurement data from each quantum current transformer is acquired. The measurement data is calibrated through cross-validation of the multi-node measurement data. This system overcomes the shortcomings of existing technologies, such as insufficient reliability of single devices and the susceptibility of traceability interruptions due to faults.

Description

Technical Field

[0001] This invention relates to the field of quantum metrology, and in particular to a traceability network system composed of multiple quantum current transformers. Background Technology

[0002] Currently, quantum current transformers based on diamond NV centers have become a research hotspot in the field of electrical force measurement due to their advantages such as high precision and wide measurement range. The measurement principle of this type of transformer relies on electron spin resonance under microwave excitation, and its measurement accuracy is highly dependent on the accuracy of the microwave source frequency.

[0003] In the prior art, Chinese invention patent applications with publication numbers CN118011303A and CN119355614A have proposed a method for remote frequency calibration of a single quantum current transformer using high-precision time and frequency signals from the BeiDou satellite. However, such solutions all focus on a point-to-point tracing mode between a single device and the satellite.

[0004] In real-world power scenarios, if the traceability link of a single device is interrupted due to equipment failure, communication anomalies, or satellite signal obstruction, the traceability process will directly fail. At the same time, the measurement data of a single device lacks effective cross-validation methods, and its random errors and systematic biases cannot be identified and suppressed, making it difficult to meet the stringent requirements of the power system for metering continuity and high reliability in terms of long-term reliability and confidence of the traceability results.

[0005] In summary, there is an urgent need in this field to construct a networked collaborative traceability architecture among quantum current transformers, which can improve the overall traceability reliability and fault tolerance of the system through multi-node data fusion and redundant link management. Summary of the Invention

[0006] The technical problem to be solved by this invention is: how to construct a networked traceability system composed of multiple quantum current transformers to overcome the problems of insufficient reliability and easy interruption of traceability due to network failure when a single device is used for independent traceability.

[0007] To address the aforementioned technical problems, this invention provides a traceability network system composed of multiple quantum current transformers, comprising: Multiple quantum current transformers are provided, each of which integrates a time-frequency transmission device. The time-frequency transmission device is used to receive external timing signals and to perform bidirectional transmission of time-frequency references between devices with the time-frequency transmission devices of other quantum current transformers. The multiple quantum current transformers are interconnected through the time-frequency transmission devices to construct a multi-node traceability network. A control system, which is communicatively connected to each of the quantum current transformers, is configured to: distribute a unified time-frequency reference to each quantum current transformer based on the bidirectional transmission of the external timing signal and the time-frequency reference between the devices, acquire the measurement data of each quantum current transformer, and calibrate the measurement data through cross-validation of the multi-node measurement data.

[0008] Furthermore, the calibration of the measurement data through cross-validation of multi-node measurement data includes: Get The original measurement values ​​of each measurement node constitute the original measurement sequence. , ; Calculate the mean of the original measurement sequence. and standard deviation ,in, ; In the formula, For the first The original measurement values ​​of each measurement node; Iterate through each raw measurement value ,like If the measured value is found to be an outlier, it will be removed, resulting in a valid data sequence after the initial filtering. ,in ; For the valid data sequence The quartile method was used for secondary filtering to obtain the final effective measurement data sequence. ,in ; Based on the final valid measurement data sequence and the standard true value of the measured physical quantity The optimal system deviation is solved using the least squares method. And utilize the optimal system deviation The measured values ​​are calibrated.

[0009] Furthermore, the method of using least squares to solve for the optimal system deviation is described. And utilize the optimal system deviation Calibrate the measured values, specifically including: Constructing the deviation objective function ; For the objective function about Find the first derivative and set it to zero to obtain the optimal system deviation. ; The calibration satisfies the following formula: .

[0010] Furthermore, the control system is also configured to monitor the operating status and communication link status of each quantum current transformer, and automatically perform redundant link switching when a faulty node or faulty link is identified.

[0011] Furthermore, when the control system performs the redundant link switching, if the main communication link is interrupted, the control system automatically switches to the fiber optic redundant link and temporarily takes over the time and frequency reference transmission and data channel of the faulty node through an adjacent quantum current transformer as a relay.

[0012] Furthermore, the unified time and frequency reference distribution mechanism includes: using the Chinese national time and frequency reference as the top-level reference, forming a collaborative link that integrates satellite time synchronization, node reference locking, bidirectional inter-node transmission, and network-wide reference unification, wherein: Under normal operating conditions, each quantum current transformer locks its local oscillation source using the BeiDou satellite timing signal as the core reference; When BeiDou satellite signals are partially blocked, redundant references for bidirectional transmission between devices are activated. The quantum current transformer that normally receives BeiDou signals is used as a temporary master reference to transmit the reference to the blocked quantum current transformer.

[0013] Furthermore, the time and frequency transmission device integrates a BeiDou multi-band timing module and a phase-locked loop and frequency synthesizer; the phase-locked loop and frequency synthesizer are used to compare the phase difference between the BeiDou timing signal and the signal transmitted between the devices in real time, and to keep the BeiDou timing signal and the signal transmitted between the devices accurately locked through feedback control.

[0014] Furthermore, each of the quantum current transformers also integrates an NV quantum current measurement system, which is used to acquire time and frequency traceability data while measuring the current.

[0015] Furthermore, the NV quantum current measurement system includes a diamond NV color center, a laser excitation device, a fluorescence detection and collection device, and a signal processing unit.

[0016] Furthermore, the control system is also configured to: set multi-level fault thresholds and collect in real time the equipment status parameters, link signal quality parameters, and reference deviation parameters of each quantum current transformer; wherein: When a parameter is detected to exceed the absolute fault threshold, it is determined to be a hard fault and a link switch is immediately triggered. When the parameters are detected to be within the range of the gradual warning threshold, a warning signal is triggered and the backup node is started to warm up.

[0017] Furthermore, the gradual warning threshold includes at least one of the following: The fluorescence intensity of the NV color center is between 0% and 85% of the rated value; The fluctuation of the measured data has a single sampling deviation greater than 1.5 ppm; The drift of the local time-frequency reference relative to the network reference is The above did not trigger a hard fault determination.

[0018] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: This invention constructs a multi-node interconnected traceability network and introduces a bidirectional time and frequency reference transmission mechanism between devices. This enables the system to distribute a unified time and frequency reference to the entire network in conjunction with BeiDou satellite timing and inter-device collaborative transmission, effectively avoiding the cumulative loss errors introduced by traditional ground links. Simultaneously, the control system utilizes cross-validation and closed-loop collaborative calibration of multi-node measurement data to suppress random errors and system deviations from individual devices, significantly improving the confidence and long-term stability of traceability results. Furthermore, the system possesses network fault self-diagnosis and redundant link dynamic switching capabilities, allowing for rapid restoration of traceability continuity when any node or link malfunctions. This comprehensively overcomes the technical shortcomings of existing technologies, such as high link loss, insufficient reliability of single devices, and easy traceability interruption due to faults, meeting the stringent requirements of high precision, high reliability, and high continuity traceability in the field of power quantum metering. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a block diagram of the traceability network system composed of multiple quantum current transformers disclosed in this invention.

[0021] Figure 2 This is a block diagram of the NV quantum measurement system disclosed in this invention.

[0022] Figure 3 This is a block diagram of the control system disclosed in this invention.

[0023] Figure 4 This is a topology diagram of fault monitoring and link switching disclosed in this invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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.

[0025] This invention aims to provide a traceability network system composed of multiple quantum current transformers, applicable to power quantum metering and time-frequency traceability scenarios, especially suitable for situations where multiple quantum current transformers in a substation need to simultaneously trace to the national time-frequency reference. By constructing a multi-node traceability network, this system achieves unified quantum time-frequency reference distribution, multi-node closed-loop collaborative calibration, and network fault self-diagnosis and dynamic link switching, thereby improving the reliability and continuity of quantum current transformer traceability results.

[0026] Please see Figure 1 The traceability network system comprises a quantum current transformer cluster and a control system. The quantum current transformer cluster consists of multiple quantum current transformers; in practical applications, the number can be three or more, depending on the substation's measurement requirements and site conditions. Each quantum current transformer serves as the core node of the traceability network, integrating a time-frequency transmission device and an NV quantum current measurement system.

[0027] In some specific implementations, the individual quantum current transformers communicate with each other via optical fiber and with the control system. The optical fiber links are used to transmit time and frequency reference signals, measurement data, and control commands. The control system is deployed in the substation control room and communicates with each quantum current transformer via optical fiber. The control system is also connected to the substation automation system to achieve coordinated management of traceability data and power grid operation data.

[0028] The following sections, in conjunction with the accompanying drawings, provide a detailed description of the quantum current transformer equipment cluster and its control system.

[0029] In this scheme, each quantum current transformer integrates a time-frequency transmission device. This device receives external timing signals and performs bidirectional time-frequency reference transmission between the time-frequency transmission devices of other quantum current transformers. Multiple quantum current transformers are interconnected through these time-frequency transmission devices to construct a multi-node traceability network.

[0030] In a further embodiment, the quantum current transformer also integrates an NV quantum current measurement system, which is used to acquire time and frequency traceability data while measuring the current.

[0031] Please see Figure 2 Each quantum current transformer's internal NV quantum current measurement system includes a diamond NV color center, a laser module, a microwave module, a filter array, a fluorescence detection and collection module, and a signal processing module. The microwave module emits microwaves in the 2.7-3.3 GHz band and radiates them to the diamond NV color center via a microwave antenna. The laser module generates a 532 nm laser source and emits it to the diamond NV color center. The diamond NV color center senses the magnetic field excited by the standard frequency source and generates a red fluorescence signal under the combined action of the microwave and laser sources. The filter array filters out light of other wavelengths besides red fluorescence, ensuring that the light signal entering the detector is primarily red fluorescence. The fluorescence detection and collection module detects the red fluorescence signal excited by the diamond NV color center and converts the light signal into an electrical signal. The signal processing module receives the electrical signal and outputs the measured physical quantity, which can be a current value, based on the microwave frequency.

[0032] Since the accuracy of current measurement directly depends on the accuracy of the microwave frequency, which in turn depends on the time-frequency reference provided by the time-frequency transfer device, this system fundamentally ensures the accuracy and consistency of current measurement results by unifying the time-frequency reference of each quantum current transformer to the national time-frequency reference.

[0033] In this scheme, the control system is communicatively connected to each quantum current transformer. The control system is configured to: distribute a unified time and frequency reference to each quantum current transformer based on the bidirectional transmission of external time synchronization signals and time and frequency references between devices, acquire the measurement data of each quantum current transformer, and calibrate the measurement data through cross-validation of multi-node measurement data.

[0034] Please see Figure 3 The control system integrates a baseline distribution and scheduling module, a data storage and preprocessing module, and a fault monitoring and link switching module.

[0035] The reference distribution and scheduling module is used to uniformly distribute and schedule the frequency signals output by the time and frequency transmission device according to requirements. For example, for nodes with high measurement accuracy requirements, a time and frequency reference with higher stability can be assigned; for nodes in calibration state, a test reference can be temporarily assigned.

[0036] The data storage and preprocessing module stores current measurement data, traceability data, and equipment status information from each device in real time, and generates a standardized traceability dataset. This module uses a standardized data format to generate a traceability dataset containing fields such as timestamps, device identifiers, measured values, calibration coefficients, and fault flags. This data can be used for offline analysis or uploaded to the higher-level metrology management system in real time.

[0037] The fault monitoring and link switching module is used to collect key status parameters of each device in real time, set multi-level fault thresholds, and automatically trigger redundant link switching when a device fault or link abnormality is detected to ensure traceability continuity.

[0038] The control system also has an interface with the substation automation system. Through this interface, the traceability network system can directly provide calibrated current measurement data to protection, measurement and control, metering and other applications. At the same time, it can also receive equipment operating status information from the automation system to assist in fault diagnosis.

[0039] Those skilled in the art will understand that the time-frequency transmission device integrated within each quantum current transformer is the key hardware foundation for achieving network-wide traceability benchmark consistency in this system. The core function of this device is to receive benchmark signals and transmit them between devices.

[0040] Specifically, the time and frequency transmission device integrates a BeiDou multi-band timing module, which can stably output a 10MHz standard frequency signal and a 1PPS (pulse per second) signal, thus directly connecting to the national time and frequency reference system. The time and frequency transmission device has a built-in high-performance phase-locked loop and frequency synthesizer, which can compare the phase difference between the BeiDou timing signal and the signal transmitted between the devices in real time, and achieve precise locking between the two through feedback control, ensuring the long-term stability of the output reference.

[0041] In this scheme, the bidirectional data transfer between devices and the BeiDou satellite time synchronization adopt a master-slave collaborative, phase-locked, and closed-loop comparison working mode. Using the National Time and Frequency Standard (NTSC) of China as the top-level reference, a complete collaborative link is formed: satellite time synchronization → node reference locking → bidirectional data transfer between nodes → unified reference across the entire network. The specific mechanism is as follows: First, satellite timing provides a top-level absolute reference. The time and frequency transmission devices of each quantum current transformer receive the 1PPS second pulse signal broadcast by the BeiDou satellite in real time. Through a high-performance phase-locked loop and frequency synthesizer, the phase and frequency of the local oscillator are precisely locked with the BeiDou timing signal, providing an absolutely reliable time and frequency reference source for the entire network.

[0042] Second, bidirectional transmission between devices enables mutual calibration of node references. Any two quantum current transformers can transmit and receive time-frequency signals bidirectionally via an optical fiber link. For example, node A sends a local 10MHz and 1PPS signal to node B, and node B synchronously sends its locked time-frequency signal back to node A. The signal transmission delay, phase difference, and frequency offset are measured in real time at both ends, and the errors introduced by link asymmetry are offset by bidirectional symmetrical transmission, thereby completing mutual calibration of references between nodes.

[0043] Third, collaborative closed-loop correction achieves network-wide benchmark consistency. The control system collects the BeiDou timing reference value and the reference deviation value transmitted bidirectionally between each node in real time, constructing a collaborative correction model with satellite timing as the primary reference and bidirectional transmission between devices as a secondary reference. Under normal operating conditions, BeiDou timing is used as the core reference, and bidirectional transmission between devices is used for fine-tuning the reference point, eliminating BeiDou reception drift of individual devices. When local satellite signals are blocked, redundant references transmitted bidirectionally between devices are activated, and the node that normally receives BeiDou signals is used as the temporary primary reference, transmitting the reference to the blocked node, thereby maintaining network-wide benchmark consistency.

[0044] Those skilled in the art will understand that the control system achieves unified quantum time and frequency reference distribution through the reference distribution scheduling module.

[0045] In some implementations, the unified quantum time and frequency reference distribution mechanism ensures that the deviation between the traceability reference of all quantum current transformers in the entire network and the National Time and Frequency Standard (NTSC) of China is less than 5 × 10⁻⁶ through the coordinated operation of BeiDou satellite time synchronization and reference transfer between devices. -10 This achieves absolute consistency with the benchmark.

[0046] Specifically, the control system first receives the reference locking status reported by the time-frequency transmission devices of each quantum current transformer. During the initial power-on phase, each node independently locks onto the BeiDou satellite timing signal. When all nodes have completed the initial locking, the control system initiates a closed-loop collaborative correction through bidirectional transmission between the devices. The control system calculates the reference deviation value between each node, identifies the node with the largest deviation as the reference drift node, and then uses the node with the smallest deviation as a reference to fine-tune the phase locking loop parameters of the drift node through control commands, so that the reference deviation between all nodes in the network converges to within a preset threshold.

[0047] When a node cannot directly receive BeiDou time synchronization due to satellite signal obstruction, the control system automatically switches the node's reference source to the inter-device bidirectional transmission link, selects an adjacent node with good BeiDou signal as a temporary primary reference, and transmits the node's time and frequency signal to the obstructed node via optical fiber. The phase-locked loop of the obstructed node uses the received inter-device transmission signal as a reference to continue maintaining a stable output of its local reference. This collaborative mechanism ensures that even in the event of a brief interruption of BeiDou signal, the network-wide tracing reference remains highly consistent.

[0048] Those skilled in the art will understand that the control system achieves closed-loop collaborative calibration through a data storage and preprocessing module and a built-in measurement data calibration algorithm. This closed-loop collaborative calibration system suppresses random errors and system biases of a single device by cross-validating the traceability results of multiple nodes, thereby improving the confidence level of the traceability results.

[0049] In some implementations, a measurement data calibration algorithm based on outlier removal and least squares method is employed. This involves using multiple quantum current transformers to simultaneously measure the same current. Since each device operates independently and has different error characteristics, outlier measurements are identified and removed using statistical methods. Then, the least squares method is used to estimate the system deviation, thereby obtaining a more accurate calibration result.

[0050] Specifically, the measurement data calibration algorithm includes the following steps: The first step is to acquire raw measurement data. (Control system data acquisition) The original measurement values ​​of each measurement node constitute the original measurement sequence. .in, For the first The original measurement values ​​of each measurement node, , To measure the total number of nodes, and This quantitative condition ensures the validity of subsequent statistical characteristic value calculations.

[0051] The second step is to calculate the mean of the original measurement sequence. and standard deviation .in:

[0052]

[0053] In the formula, The total number of measurement nodes, used to characterize the sample size of the measurement data; For the first The original measurement values ​​of each measurement node; It is the arithmetic mean of the original measurement sequence, reflecting the central tendency of the measurement data, and serving as a benchmark for outlier identification; The standard deviation of the original measurement sequence reflects the dispersion of the measurement data and is used to determine the threshold for outlier detection.

[0054] The third step involves initial outlier filtering based on the 3σ criterion. This involves iterating through each measurement value in the original measurement sequence. Valid data is selected according to the following criteria: like If so, then retain the measured value. ; like If the measurement value is found to be a gross error outlier, it will be discarded.

[0055] The collected and retained measurements form the effective data sequence after initial filtering. ,in The first filter after initial filtering One valid measurement value, This represents the number of valid measurement nodes after the initial filtering, and .

[0056] The fourth step involves a secondary filtering process based on the quartile method to eliminate extreme outliers. The quartile method is a robust statistical outlier detection method, particularly suitable for non-normally distributed data. The specific steps are as follows: valid data sequence Sort the sequence in ascending order from smallest to largest to obtain the sorted sequence. .

[0057] Calculate the sorted sequence lower quartiles and upper quartiles Among them, the lower quartiles It refers to the value located at the 25th percentile in the sorted sequence, meaning that 25% of the measured values ​​are less than or equal to 25%. 75% of the measured values ​​are greater than or equal to Upper quartiles It refers to the value located at the 75th percentile in the sorted sequence, meaning that 75% of the measured values ​​are less than or equal to the 75th percentile. 25% of the measurements are greater than or equal to .

[0058] Calculate interquartile range It satisfies the calculation formula: . Used to characterize the discrete range of data, reflecting the degree of concentration in the data distribution. Retaining values ​​within the interval... The measured values ​​within the specified range are excluded, and the excluded measured values ​​are determined to be extreme deviation values.

[0059] The collected and retained measurements form the final valid measurement data sequence. ,in The second filter One valid measurement value, To determine the final number of valid measurement nodes, and The sequence This is clean data without outliers, used for subsequent system bias correction.

[0060] The fifth step is to solve for the optimal system deviation using the least squares method. This includes the following steps: Constructing the deviation objective function , Defined as the sum of squared deviations between all final valid measurements and the true values, the objective function is... The calculation formula is:

[0061] In the above formula, The sum of squared deviations serves as the optimization objective for correcting system deviations; the smaller the value, the higher the correction accuracy. The final effective number of measurement nodes, i.e., the number of clean data samples after secondary filtering; The second filter One valid measurement value; The standard true value (known benchmark value) of the measured physical quantity is used as a reference benchmark for deviation calculation.

[0062] Solving for the optimal system deviation : Definition of the first System deviation of each measurement node The difference between the final valid measurement value and the true value of this node, i.e. For the objective function about Find the first derivative and set it to zero to obtain the optimal system deviation. At this point, the sum of squared deviations... The optimal system deviation reaches its minimum value. It includes all system deviation components such as zero-point drift and gain error of the node.

[0063] Step 6: Feedback the calibration measurement results. Utilize the optimal system deviation obtained from the solution. The original measurement values ​​of each measurement node are calibrated using the following formula:

[0064] Will Substituting into the calibration formula above, we can obtain This means achieving complete correction of system bias and eliminating the influence of zero drift and gain error on measurement results.

[0065] In actual operation, the control system periodically executes the above calibration algorithm. After each calibration cycle, the control system uses the calibrated measurement data as the output value of that node, and simultaneously sets the optimal system deviation... The data is stored in the data storage module for measurement data correction in the next cycle. This is used when a system deviation is detected at a certain node. When a sudden change occurs or exceeds the preset range, the control system determines that the node may be faulty and triggers the fault monitoring and link switching module to perform diagnosis.

[0066] In a further embodiment, the fault monitoring and link switching module in the control system is crucial for ensuring the continuity of the tracing process. Specifically, the fault monitoring and link switching module collects key status parameters of each device in real time, including device operating status, link signal quality, and reference deviation, and sets multi-level fault thresholds. When a device fault or link anomaly is detected, redundant link switching is automatically triggered to ensure the continuity of the tracing process under extreme operating conditions. In one specific embodiment, the fault recovery time is less than 100ms.

[0067] To more clearly illustrate the working process of fault monitoring and link switching, the following will combine... Figure 4 The example of the fault scenario shown is described in detail.

[0068] Please see Figure 4 Consider the following fault scenario: A quantum current transformer A in a substation shuts down due to a hardware malfunction, and its main communication fiber optic cable to the control system breaks, causing the node to be unable to measure, the time and frequency reference to be interrupted, and data upload to fail. In this situation, the system needs to ensure the continuity and accuracy of traceability across the entire network.

[0069] The fault monitoring and link switching module of this system operates according to the following process: First, real-time fault monitoring, which takes approximately 0-20ms. The fault monitoring module of the control system collects equipment status parameters, link quality parameters, and reference deviation parameters every 10ms. Specifically, for quantum current transformer A, the equipment status parameters are manifested as no signal output, NV color center fluorescence intensity of 0, and measurement data interruption; the link quality parameters are manifested as a main fiber link signal-to-noise ratio of 0, infinite time delay, and signal loss; the reference deviation parameter is manifested as the deviation between the time-frequency reference of this node and the reference of the entire network far exceeding the threshold.

[0070] In addition to the absolute fault detection conditions such as no output, signal-to-noise ratio of 0, and infinite latency mentioned above, this system also adds a gradual change warning threshold. The gradual change warning threshold includes, but is not limited to, the following situations: NV color center fluorescence intensity is between 0% and 85% of the rated value; measurement data fluctuation rate single sampling deviation is greater than 1.5 ppm and exceeds the limit for 3 consecutive frames without data interruption; local time-frequency reference drift relative to the network reference is within 3 × 10⁻⁶. -10 The above conditions do not trigger a hard fault determination. Within this determination condition, the system only triggers an early warning signal and simultaneously starts the backup node to warm up and standby. In this solution, the setting of the gradual early warning threshold enables the system to detect potential faults in advance, realize predictive maintenance, and avoid the interruption of tracing due to sudden faults.

[0071] Second, intelligent fault diagnosis, this stage takes approximately 20-50ms. The control system triggers multi-level fault diagnosis logic: if there is no measurement data, it is determined that the equipment has a hardware fault; if the main link signal is lost, it is determined that the main communication link is interrupted. The comprehensive judgment result is: quantum current transformer A has failed, the main link is unavailable, and redundant links and backup node references need to be activated.

[0072] Third, the redundant link is dynamically switched, a process that takes approximately 50-90ms. For link switching, the control system automatically switches to the fiber optic redundant link, temporarily taking over the time and frequency reference transmission and data channel of the faulty node via the relay link of quantum current transformer B. For reference completion, quantum current transformer B, adjacent to the faulty node and with stable BeiDou timing, is selected as the temporary reference node. Through bidirectional transmission between devices, 10MHz and 1PPS signals are distributed to the redundant link to ensure uninterrupted time and frequency reference in the faulty area.

[0073] Fourth, ensuring accuracy in tracing the source, this stage takes approximately 90-100ms. The closed-loop collaborative calibration system automatically eliminates invalid data from quantum current transformer A, excluding it from the least squares calculation. Simultaneously, it increases the measurement weight of quantum current transformer B, using the least squares method to fill in the data gaps during the fault period. The time-frequency reference deviation remains less than 5×10 throughout the switching process. -10 The traceability accuracy is maintained within ±0.5ppm, achieving continuous traceability without interruption or accuracy degradation.

[0074] Fifth, fault alarm and self-healing. The control system pushes fault alarms to the host computer and records the fault type, time, and switching process. After the fault is cleared, the control system automatically reconnects to quantum current transformer A, completes the reference relocking, and restores the normal topology of the entire network.

[0075] Through the above mechanism, this system can still maintain the continuity and accuracy of network-wide traceability even in the event of a single device failure or link interruption, thus meeting the power system's requirements for high reliability of metering equipment.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A traceability network system composed of multiple quantum current transformers, characterized in that, include: Multiple quantum current transformers are provided, each of which integrates a time-frequency transmission device. The time-frequency transmission device is used to receive external timing signals and to perform bidirectional transmission of time-frequency references between devices with the time-frequency transmission devices of other quantum current transformers. The multiple quantum current transformers are interconnected through the time-frequency transmission devices to construct a multi-node traceability network. A control system, which is communicatively connected to each of the quantum current transformers, is configured to: distribute a unified time-frequency reference to each quantum current transformer based on the bidirectional transmission of the external timing signal and the time-frequency reference between the devices, acquire the measurement data of each quantum current transformer, and calibrate the measurement data through cross-validation of the multi-node measurement data.

2. The traceability network system composed of multiple quantum current transformers according to claim 1, characterized in that, The calibration of measurement data through cross-validation of multi-node measurement data includes: Get The original measurement values ​​of each measurement node constitute the original measurement sequence. , ; Calculate the mean of the original measurement sequence. and standard deviation ,in, ; In the formula, For the first The original measurement values ​​of each measurement node; Iterate through each raw measurement value ,like If the measured value is found to be an outlier, it will be removed, resulting in a valid data sequence after the initial filtering. ,in ; For the valid data sequence The quartile method was used for secondary filtering to obtain the final effective measurement data sequence. ,in ; Based on the final valid measurement data sequence and the standard true value of the measured physical quantity The optimal system deviation is solved using the least squares method. And utilize the optimal system deviation The measured values ​​are calibrated.

3. The traceability network system composed of multiple quantum current transformers according to claim 2, characterized in that, The least squares method is used to solve for the optimal system deviation. And utilize the optimal system deviation Calibrate the measured values, specifically including: Constructing the deviation objective function ; For the objective function about Find the first derivative and set it to zero to obtain the optimal system deviation. ; The calibration satisfies the following formula: .

4. The traceability network system composed of multiple quantum current transformers according to claim 1, characterized in that, The control system is also configured to monitor the operating status and communication link status of each quantum current transformer, and automatically perform redundant link switching when a faulty node or faulty link is detected.

5. The traceability network system composed of multiple quantum current transformers according to claim 4, characterized in that, When the control system performs the redundant link switching, if the main communication link is interrupted, the control system automatically switches to the fiber optic redundant link and temporarily takes over the time and frequency reference transmission and data channel of the faulty node through an adjacent quantum current transformer as a relay.

6. The traceability network system composed of multiple quantum current transformers according to claim 1, characterized in that, The unified time and frequency reference distribution mechanism includes: using the Chinese national time and frequency reference as the top-level reference, forming a collaborative link that integrates satellite time synchronization, node reference locking, bidirectional inter-node transmission, and network-wide reference unification, wherein: Under normal operating conditions, each quantum current transformer locks its local oscillation source using the BeiDou satellite timing signal as the core reference; When BeiDou satellite signals are partially blocked, redundant references for bidirectional transmission between devices are activated. The quantum current transformer that normally receives BeiDou signals is used as a temporary master reference to transmit the reference to the blocked quantum current transformer.

7. The traceability network system composed of multiple quantum current transformers according to claim 1, characterized in that, The time and frequency transmission device integrates a BeiDou multi-band timing module and a phase-locked loop and frequency synthesizer; the phase-locked loop and frequency synthesizer are used to compare the phase difference between the BeiDou timing signal and the signal transmitted between the devices in real time, and to keep the BeiDou timing signal and the signal transmitted between the devices accurately locked through feedback control.

8. The traceability network system composed of multiple quantum current transformers according to claim 1, characterized in that, Each of the quantum current transformers also integrates an NV quantum current measurement system, which is used to acquire time and frequency traceability data while measuring the current; wherein, the NV quantum current measurement system includes a diamond NV color center, a laser excitation device, a fluorescence detection and collection device, and a signal processing unit.

9. The traceability network system composed of multiple quantum current transformers according to claim 4, characterized in that, The control system is also configured to: set multi-level fault thresholds and collect in real-time equipment status parameters, link signal quality parameters, and reference deviation parameters of each quantum current transformer; wherein: When a parameter is detected to exceed the absolute fault threshold, it is determined to be a hard fault and a link switch is immediately triggered. When the parameters are detected to be within the range of the gradual warning threshold, a warning signal is triggered and the backup node is started to warm up.

10. The traceability network system composed of multiple quantum current transformers according to claim 9, characterized in that, The gradual warning threshold includes at least one of the following: The fluorescence intensity of the NV color center is between 0% and 85% of the rated value; The fluctuation of the measured data has a single sampling deviation greater than 1.5 ppm; The drift of the local time-frequency reference relative to the network reference is The above did not trigger a hard fault determination.

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