Measurement and data processing system of intelligent pincerlike on-load phase meter

Abstract

The invention relates to the technical field of pincerlike phase meters, and discloses a measurement and data processing system of an intelligent pincerlike on-load phase meter, which comprises a low-power-consumption embedded mobile application platform which is constructed and carried with a Linux operating system and an SQLite database based on an ARMCortex-A series processor and is used for coordinating the work of each module of the system, executing data management, algorithm operation and application program control; the voltage acquisition module adopts a voltage transformer based on the electromagnetic induction principle, the input side of the voltage acquisition module is connected with a high-voltage line, and the output side of the voltage acquisition module is coupled with the isolation type delta-sigma modulator through a differential amplifier, so that electrical isolation and digital conversion of three-phase voltage signals are realized; and the current acquisition module adopts a closed-loop Hall current sensor, and is internally provided with a magnetism gathering ring and a compensation coil. The purpose of the measurement and data processing system of the intelligent pincerlike on-load phase meter is to solve the problem that an existing traditional phase meter is single in measurement data and cannot reflect the actual operation state of a power system in time.

Description

Technical Field

[0001] The present invention relates to the technical field of clamp-on phase meters, in particular to a measurement and data processing system for an intelligent clamp-on load phase meter. Background Art

[0002] In existing technologies, clamp-on phase meters, as an important tool for power system testing, have been widely used. They play an indispensable role in the daily operation, maintenance, and new construction or renovation projects of power systems. They are mainly used to measure the phase of voltage and current, providing key data support for phase calibration, troubleshooting, and performance evaluation of power systems.

[0003] In terms of online measurement functions, traditional phase meters have single measurement data and are limited to the amplitude and phase measurement of voltage and current. They lack the ability to measure key electrical parameters such as active power, reactive power, apparent power and power factor online. At the same time, their data collection and recording process lacks real-time performance and cannot reflect the actual operating status of the power system in a timely manner, which has certain defects. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing traditional phase meter has single measurement data and cannot timely reflect the actual operating status of the power system, and to propose a measurement and data processing system for an intelligent clamp-on load phase meter.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A measurement and data processing system for an intelligent clamp-on load phase meter, comprising:

[0007] A low-power embedded mobile application platform based on the ARM Cortex-A series processor, equipped with a Linux operating system and SQLite database, which coordinates the work of various system modules and performs data management, algorithm calculations and application control;

[0008] The voltage acquisition module uses a voltage transformer based on the principle of electromagnetic induction. The input side is connected to the high-voltage line, and the output side is coupled with an isolated Δ-Σ modulator through a differential amplifier to achieve electrical isolation and digital conversion of the three-phase voltage signal.

[0009] The current acquisition module uses a closed-loop Hall current sensor with a built-in magnetic ring and compensation coil to achieve non-contact current measurement through the principle of magnetic balance;

[0010] The data acquisition and processing module integrates a 16-bit high-speed analog-to-digital converter and FPGA logic unit to collect the instantaneous values ​​of three-phase voltage and current in real time, and calculates the voltage amplitude, current amplitude, phase difference, frequency, active power, reactive power and power factor through discrete Fourier transform;

[0011] The wiring identification module, based on six pre-stored characteristic phase tables, including standard phase and five incorrect wiring phases, combined with the CT polarity compensation algorithm, performs point-by-point error comparison between the measured current phase and the characteristic phase, automatically determining reverse polarity, incorrect phase sequence, or correct wiring, and dynamically marking the error points through a vector diagram.

[0012] On the basis of the above technical solution, the present invention can also be improved as follows.

[0013] Furthermore, the multi-mode isolation switching method of the voltage acquisition module includes:

[0014] Critical frequency calculation formula:

[0015]

[0016] in, is the equivalent inductance of the voltage transformer, For optocoupler coupling capacitance, when the input signal frequency When the electromagnetic induction mode is used, When the signal-to-noise ratio is less than 40dB, an alarm is triggered and the isolation module is reset.

[0017] Furthermore, the harmonic analysis method of the data acquisition and processing module includes:

[0018] Adaptive threshold filtering formula:

[0019]

[0020] in, is the fundamental amplitude, is the noise standard deviation of the first 10 harmonics;

[0021] THD correction formula:

[0022]

[0023] in, is the sampling frequency, is the fundamental frequency, only The harmonic components of the signal are selected and the rest are treated as noise and removed.

[0024] Furthermore, the current acquisition module also includes an overcurrent protection circuit, specifically including:

[0025] Connect a transient voltage suppression diode in parallel at the output end of the sensor to absorb surge voltage;

[0026] Adopting magnetic saturation detection circuit, when the primary current exceeds the upper limit of the range, the power supply of the compensation coil is automatically cut off and the sound and light alarm is triggered;

[0027] Overcurrent event recording function, storing timestamp and peak current value in local Flash memory.

[0028] Furthermore, the phase compensation algorithm of the wiring determination module specifically includes the following steps:

[0029] Polarity reverse compensation formula:

[0030]

[0031] in, The fixed phase difference caused by the transformer winding connection group number is pre-stored in the database through a table lookup method;

[0032] Minimum circumference difference determination formula:

[0033]

[0034] in, There are six pre-stored characteristic phase values, namely 0°, 60°, 120°, 180°, 240°, and 300°. When the wiring is correct,

[0035] Stability verification formula:

[0036]

[0037] in, is the number of measurement points for 10 consecutive power frequency cycles. Check that the wiring is stable.

[0038] Furthermore, the system also includes a data display module and a remote collaboration module;

[0039] The data display module uses a 7-inch capacitive touch screen and supports three modes: waveform diagram, vector diagram and table. Users can customize the reference voltage channel and zoom or pan the waveform through gestures.

[0040] The remote collaboration module has a built-in dual-band WiFi module and is connected to the Alibaba Cloud platform via the MQTT protocol, enabling real-time upload of measurement data, cloud storage, and simultaneous access by multiple terminals. It also supports remote triggering of measurement commands and report downloads.

[0041] Furthermore, the vector graph generation method of the data display module includes:

[0042] Taking the phase A voltage as the reference, the normalized display amplitude is per unit length;

[0043] Dynamic color mapping formula:

[0044]

[0045] in, This is the difference between the current phase and the reference voltage phase. When the user clicks the vector arrow, Fourier harmonic analysis is triggered, and a pop-up window displays the harmonic distortion rate and the amplitude ratios of the first five harmonics.

[0046] Furthermore, the remote collaboration module is also provided with an offline module, which continuously monitors the network connection status for the system. When a network interruption is detected, the real-time collected voltage, current and phase data are automatically stored in a structured format to the local SD card. The data record contains a device identifier, a high-precision timestamp and a measurement value, and is stored in ascending order by timestamp. After the network is restored, the system starts the breakpoint resumption mechanism, first verifying the integrity of the local cached data, and then based on the block transmission function of the HTTP protocol, continues to upload the unfinished data block from the last successfully transmitted byte position to ensure the continuity and integrity of data transmission. After the cloud server receives the data, it performs a timestamp consistency check, adds an abnormal status mark to the data record with timing anomalies, including timestamp jumps, interval overruns, etc., and stores the abnormal data in the queue for review. At the same time, a review task is generated to notify the operation and maintenance personnel. The operation and maintenance personnel view the details of the abnormal data through the management interface, confirm the validity of the data after manual verification, and complete the final data archiving process.

[0047] Furthermore, the system also includes a report generation module, which is a pre-set report template that complies with the standards of the Southern Power Grid and includes fields such as test time, voltage / current effective value, phase angle, power parameters and wiring judgment results; the generation function is triggered by the touch screen to automatically fill the current measurement data into the template, and supports exporting to PDF or Excel format, and uses the SHA-256 algorithm to digitally sign the report file to ensure that the data cannot be tampered with.

[0048] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0049] The low-power embedded mobile application platform of the present invention is built based on the ARMCortex-A series processor and is equipped with a Linux operating system and an SQLite database. It can not only efficiently coordinate the work of various modules of the system to ensure stable operation of the system, but also rely on powerful data management functions and fast algorithm computing capabilities to process and store large amounts of collected data in real time. Compared with the lack of real-time data collection and recording in traditional phase meters, it greatly improves the data processing efficiency and real-time performance, and can timely reflect the actual operating status of the power system; the voltage acquisition module adopts a voltage transformer based on the principle of electromagnetic induction, combined with a differential amplifier and an isolated Δ-Σ modulator to achieve electrical isolation and digital conversion of three-phase voltage signals, ensuring the accuracy and stability of voltage signal acquisition, and providing a reliable data basis for subsequent precise measurement and analysis; the current acquisition module uses a closed-loop Hall current sensor to achieve non-contact current measurement based on the principle of magnetic balance. Compared with traditional measurement methods, this method can effectively avoid interference with the circuit and has higher measurement accuracy; the data acquisition and processing module integrates a 16-bit high-speed analog-to-digital converter and FPGA The logic unit collects the instantaneous values ​​of three-phase voltage and current in real time, and calculates the voltage amplitude, current amplitude, phase difference, frequency, active power, reactive power and power factor through discrete Fourier transform. This makes up for the shortcomings of traditional phase meters in terms of single measurement data and lack of online measurement capabilities for key electrical parameters. It can provide more comprehensive and rich power parameters to meet the multi-dimensional detection needs of the power system. The wiring judgment module is based on six pre-stored characteristic phase tables and combined with the CT polarity compensation algorithm to automatically determine reverse polarity, incorrect phase sequence or correct wiring, and dynamically mark error points through vector diagrams. It can quickly and accurately identify power system wiring problems, provide strong support for power system troubleshooting and phase calibration, and reduce the error and time cost of manual detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The present invention provides a system block diagram of a measurement and data processing system for an intelligent clamp-on-load phase meter. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] Combine Figure 1 As shown, the measurement and data processing system of an intelligent clamp-on load phase meter of the present invention includes:

[0053] A low-power embedded mobile application platform based on the ARM Cortex-A series processor, equipped with a Linux operating system and SQLite database, which coordinates the work of various system modules and performs data management, algorithm calculations and application control;

[0054] The voltage acquisition module uses a voltage transformer based on the principle of electromagnetic induction. The input side is connected to the high-voltage line, and the output side is coupled with an isolated Δ-Σ modulator through a differential amplifier to achieve electrical isolation and digital conversion of the three-phase voltage signal.

[0055] The current acquisition module uses a closed-loop Hall current sensor with a built-in magnetic ring and compensation coil to achieve non-contact current measurement through the principle of magnetic balance;

[0056] The data acquisition and processing module integrates a 16-bit high-speed analog-to-digital converter and FPGA logic unit to collect the instantaneous values ​​of three-phase voltage and current in real time, and calculates the voltage amplitude, current amplitude, phase difference, frequency, active power, reactive power and power factor through discrete Fourier transform;

[0057] The wiring identification module, based on six pre-stored characteristic phase tables, including standard phase and five incorrect wiring phases, combined with the CT polarity compensation algorithm, performs point-by-point error comparison between the measured current phase and the characteristic phase, automatically determining reverse polarity, incorrect phase sequence, or correct wiring, and dynamically marking the error points through a vector diagram.

[0058] In a preferred embodiment, the present invention can be further configured as follows: the multi-mode isolation switching method of the voltage acquisition module includes:

[0059] Critical frequency calculation formula:

[0060]

[0061] in, is the equivalent inductance of the voltage transformer, For optocoupler coupling capacitance, when the input signal frequency When the electromagnetic induction mode is used, When the input signal frequency is low, the electromagnetic induction mode is used, and the voltage signal can be efficiently collected by using the characteristics of the voltage transformer; when the frequency is high, the optocoupler mode is switched to better adapt to high-frequency signals, reduce signal interference, and improve the accuracy of signal acquisition. At the same time, the signal-to-noise ratio of the output signal is monitored in real time by the FPGA. Once the signal-to-noise ratio is less than 40dB, an alarm is triggered and the isolation module is reset. Signal quality problems can be discovered and processed in time to avoid measurement errors caused by factors such as signal interference, thereby ensuring the reliability of voltage signal acquisition.

[0062] In order to further improve the performance and reliability of the voltage acquisition module, a temperature compensation mechanism for the voltage transformer and optocoupler devices can also be added. Since the performance of the voltage transformer and optocoupler will be affected by temperature changes, for example, temperature rise may cause the inductance value of the voltage transformer to drift, and the coupling efficiency of the optocoupler may also change. Therefore, a temperature sensor is set in the system to monitor the working environment temperature in real time, and the relevant parameters are dynamically adjusted according to the temperature changes. Specifically, when the temperature changes, the equivalent inductance of the voltage transformer is adjusted according to the pre-established temperature-parameter change model. The calculation is corrected, and the parameters such as signal gain in the optocoupler mode are compensated and adjusted. At the same time, the signal processing algorithm is optimized at the software level, and the voltage signals collected at different temperatures are filtered and corrected to further reduce the impact of temperature factors on the measurement results. It ensures that the voltage acquisition module can stably and accurately collect voltage signals under different ambient temperature conditions, providing a high-quality data basis for subsequent data processing and analysis.

[0063] In a preferred embodiment, the present invention can be further configured as follows: the harmonic analysis method of the data acquisition and processing module includes:

[0064] Adaptive threshold filtering formula:

[0065]

[0066] in, is the fundamental amplitude, is the noise standard deviation of the first 10 harmonics;

[0067] THD correction formula:

[0068]

[0069] in, is the sampling frequency, is the fundamental frequency, only The harmonic components of the signal are selected, and the rest are treated as noise and eliminated. The threshold is determined by comprehensively considering the fundamental amplitude and noise standard deviation through the adaptive threshold filtering formula, which can accurately distinguish between effective harmonic components and noise, avoid measurement errors caused by noise interference, and improve the accuracy of harmonic analysis. The THD correction formula further combines the sampling frequency and the fundamental frequency to correct the total harmonic distortion (THD), making the assessment of harmonic content more accurate. This method effectively makes up for the shortcomings of traditional phase meters in harmonic analysis, and can provide more reliable data support for power quality assessment and fault diagnosis of power systems. It helps power system operation and maintenance personnel to more accurately grasp the system operation status, promptly discover potential problems and take corresponding measures.

[0070] On the existing basis, the analysis and processing of interharmonics can be increased. Interharmonics are harmonic components with frequencies that are non-integer multiples of the fundamental wave. In modern power systems, due to the use of a large number of power electronic equipment, the problem of interharmonics has become increasingly prominent. First, in the data acquisition link, the sampling frequency is increased and the sampling strategy is optimized to ensure that the interharmonic signals can be accurately captured. Then, at the algorithm level, a detection algorithm specifically for interharmonics is introduced, such as an interharmonic detection method based on synchronous compression wavelet transform. This method can effectively improve the resolution of interharmonics and accurately identify the frequency and amplitude of interharmonics. At the same time, the interharmonic analysis results are combined with the existing harmonic analysis results to establish a more complete power quality assessment system. This can not only provide users with more detailed power quality reports, but also provide a more comprehensive reference basis for the planning, design and operation optimization of the power system, helping the power system to better deal with complex power quality issues.

[0071] In a preferred embodiment of the present invention, the current acquisition module may be further configured as follows: the current acquisition module further includes an overcurrent protection circuit, specifically comprising:

[0072] Connect a transient voltage suppression diode in parallel at the output end of the sensor to absorb surge voltage;

[0073] Adopting magnetic saturation detection circuit, when the primary current exceeds the upper limit of the range, the power supply of the compensation coil is automatically cut off and the sound and light alarm is triggered;

[0074] The overcurrent event recording function stores timestamps and peak current values ​​in local Flash memory. The parallel transient voltage suppression diode can quickly absorb surge voltage, preventing damage to the sensor and subsequent circuits, ensuring the hardware security of the current acquisition module. The magnetic saturation detection circuit automatically cuts off the power supply to the compensation coil and triggers an audible and visual alarm when the primary current exceeds the upper range limit. This prevents measurement distortion caused by magnetic saturation of the sensor due to excessive current. It also prompts maintenance personnel to promptly handle abnormalities through the alarm, avoiding more serious failures caused by prolonged overcurrent conditions. The overcurrent event recording function stores timestamps and peak current values ​​in local Flash memory, providing accurate data for subsequent fault analysis, helping to identify the cause of overcurrent and assess equipment damage. This solves the problem of traditional phase meters lacking overcurrent protection and event recording mechanisms, making it difficult to handle overcurrent faults and subsequent analysis. This significantly improves the reliability and practicality of the current acquisition module.

[0075] In order to further improve the function of the overcurrent protection circuit, a communication module with the host computer can be added. When an overcurrent event occurs, not only will an audible and visual alarm and data recording be performed locally, but the overcurrent information (including timestamp, peak current value, overcurrent duration, etc.) can also be uploaded to the power system monitoring center or the mobile terminal of the operation and maintenance personnel in real time through wireless or wired communication methods (such as 4G, Ethernet, etc.). At the same time, an intelligent analysis function is set in the software system of the current acquisition module. Based on the data of multiple overcurrent events, the law of overcurrent occurrence can be analyzed, such as whether overcurrent occurs frequently in a specific time period and under specific working conditions, to predict potential overcurrent risks in advance and issue early warnings to the operation and maintenance personnel so that preventive maintenance measures can be taken, such as adjusting equipment operating parameters, replacing aging components, etc., to further improve the safety and stability of power system operation.

[0076] In a preferred embodiment, the present invention can be further configured as follows: the phase compensation algorithm of the wiring determination module specifically includes the following steps:

[0077] Polarity reverse compensation formula:

[0078]

[0079] in, The fixed phase difference caused by the transformer winding connection group number is pre-stored in the database through a table lookup method;

[0080] Minimum circumference difference determination formula:

[0081]

[0082] in, There are six pre-stored characteristic phase values, namely 0°, 60°, 120°, 180°, 240°, and 300°. When the wiring is correct,

[0083] Stability verification formula:

[0084]

[0085] in, is the number of measurement points for 10 consecutive power frequency cycles. The stability of the wiring is confirmed at the same time. The reverse polarity compensation formula takes into account the fixed phase difference caused by the transformer winding connection group number. Through compensation calculation, it can effectively correct the phase deviation caused by reverse polarity and accurately restore the actual phase situation. The minimum circular difference judgment formula uses the pre-stored characteristic phase value to accurately compare the measured phase with the standard phase, and judge whether the wiring is correct within a very small error range, thereby improving the accuracy of wiring judgment. The stability verification formula evaluates the stability of the wiring by calculating the residuals of multiple consecutive power frequency cycle measurement points, which can avoid misjudgment caused by factors such as instantaneous interference, and ensure that the wiring judgment results are reliable. This algorithm effectively solves the problem of inaccurate wiring judgment and susceptibility to interference of traditional phase meters, provides accurate and reliable data support for phase calibration and troubleshooting of power systems, and improves the efficiency and accuracy of power system operation and maintenance.

[0086] In order to further improve the performance of the wiring identification module, data interaction functions with other power equipment monitoring systems can be added. On the one hand, data can be connected with the integrated automation system of the substation to obtain information such as the current power system operation mode and equipment parameters, and combined with this information to more accurately analyze the wiring situation. For example, when the system operation mode changes and the flow direction changes, the phase compensation algorithm can be dynamically adjusted according to the new operating parameters to improve the adaptability of wiring identification. On the other hand, data can be shared with the fault recording device. When a system failure occurs, the accuracy of the wiring judgment result can be further verified by comparing the fault recording data with the data of the wiring identification module, and a more comprehensive data basis can be provided for fault analysis. At the same time, a statistical analysis function of the historical wiring judgment results is added to the interface of the wiring identification module, and the wiring error type, occurrence frequency and other information in different time periods are displayed in the form of charts to help operation and maintenance personnel summarize the rules, take preventive measures in advance, and reduce the occurrence rate of failures caused by wiring errors.

[0087] In a preferred embodiment, the present invention can be further configured as follows: the system further includes a data display module and a remote collaboration module;

[0088] The data display module uses a 7-inch capacitive touch screen and supports three modes: waveform diagram, vector diagram and table. Users can customize the reference voltage channel and zoom or pan the waveform through gestures.

[0089] The remote collaboration module has a built-in dual-band WiFi module, which is connected to the Alibaba Cloud platform via the MQTT protocol, realizing real-time upload of measurement data, cloud storage and multi-terminal synchronous access, supporting remote triggering of measurement instructions and report downloading, and adopting a 7-inch capacitive touch screen. It provides three modes: waveform diagram, vector diagram and table, enriching the data presentation form, and facilitating users to observe and analyze measurement data from different angles. Users can also customize the reference voltage channel and zoom or translate the waveform through gesture operations, enhancing the convenience and flexibility of operation and making data viewing and analysis more efficient. The remote collaboration module has a built-in dual-band WiFi module, which is connected to the Alibaba Cloud platform via the MQTT protocol, realizing real-time upload of measurement data, cloud storage and multi-terminal synchronous access, breaking the spatial limitations and facilitating personnel in different locations to obtain data in a timely manner. At the same time, it supports remote triggering of measurement instructions and report downloading, greatly improving the collaboration and efficiency of work, solving the problem that traditional phase meters cannot meet the needs of remote operation and data sharing, and providing a more convenient tool for the operation, maintenance and management of power systems.

[0090] To further expand the functions of the data display module and the remote collaboration module, intelligent analysis and early warning functions can be added to the data display module, and built-in algorithms can be used to perform intelligent analysis on real-time measurement data. When parameters such as voltage, current, and power are monitored to be out of the normal range or experience abnormal fluctuations, an early warning prompt will be displayed on the screen with eye-catching colors and icons, and a brief abnormal analysis report will be automatically generated to help users quickly identify the problem. For the remote collaboration module, interfaces with other power system management software can be added, such as power dispatching automation systems, equipment asset management systems, etc., to achieve deep data integration and sharing. For example, measurement data can be associated with equipment ledger information to facilitate operation and maintenance personnel to quickly obtain relevant equipment parameters and historical maintenance records when viewing measurement data, providing more comprehensive support for equipment status assessment and fault diagnosis. Video monitoring functions can also be integrated into the remote collaboration module. When a measurement command is triggered remotely, the on-site video monitoring screen can be synchronously called to allow remote operators to more intuitively understand the situation at the measurement site.

[0091] In a preferred embodiment, the present invention can be further configured as follows: the vector image generation method of the data display module includes:

[0092] Taking the phase A voltage as the reference, the normalized display amplitude is per unit length;

[0093] Dynamic color mapping formula:

[0094]

[0095] in, It is the difference between the current phase and the reference voltage phase. When the user clicks the vector arrow, Fourier harmonic analysis is triggered, and a pop-up window displays the harmonic distortion rate and the proportion of the first five harmonic amplitudes. The amplitude is normalized and displayed based on the phase A voltage, making the presentation of the vector diagram standardized and intuitive, allowing users to quickly understand the amplitude relationship between the voltage and current of each phase. The dynamic color mapping formula assigns different colors to the vector based on the difference between the current phase and the reference voltage phase, presenting the abstract phase difference information in a visual manner. Users can quickly judge the size range of the phase difference by color, enhancing the readability of the data. In addition, the user clicks the vector arrow to trigger Fourier harmonic analysis and a pop-up window displays the harmonic distortion rate and the proportion of the first five harmonic amplitudes, allowing users to deeply explore the harmonic characteristics of the power signal, providing richer power parameter information, making up for the shortcomings of traditional phase meters in harmonic analysis display, and providing more powerful support for power system operation monitoring and fault diagnosis.

[0096] To further enhance the functionality and practicality of the vector diagram in the data display module, a three-dimensional display mode of the vector diagram can be added. In the three-dimensional mode, in addition to displaying the amplitude and phase information of the voltage and current, the time dimension can also be included to display the changing trend of the power signal over time in the form of animation. For example, by rotating and scaling the three-dimensional vector diagram, the user can observe the dynamic changes of the power signal in a power frequency cycle or longer from different perspectives, and more intuitively discover abnormal fluctuations in the signal. At the same time, an intelligent annotation function is added to the vector diagram. When the mouse hovers over the vector, it not only displays the value of the electrical parameter represented by the current vector, but also automatically associates and displays the name, location and other information of the related equipment, as well as the normal operating range of the electrical parameter. If the electrical parameter exceeds the normal range, the annotation color will automatically change to prompt the user. In addition, artificial intelligence algorithms can be introduced to perform real-time analysis of the vector diagram data. When potential power system operation risks are found, the user will be informed with special marks and prompt information on the vector diagram, and the corresponding risk warning level and handling suggestions will be provided.

[0097] In a preferred embodiment, the present invention can be further configured as follows: the remote collaboration module is also provided with an offline module, which continuously monitors the network connection status for the system. When a network interruption is detected, the real-time collected voltage, current and phase data are automatically stored in a structured format to the local SD card. The data record contains a device identifier, a high-precision timestamp and a measurement value, and is stored in ascending order by timestamp. After the network is restored, the system starts a breakpoint resume mechanism, first verifies the integrity of the local cached data, and then continues to upload the unfinished data block from the last successfully transmitted byte position based on the block transmission function of the HTTP protocol to ensure the continuity and integrity of the data transmission. After the cloud server receives the data, it performs a timestamp consistency check, adds an abnormal status mark to the data record with timing anomalies, including timestamp jumps, interval overruns, etc., and stores the abnormal data in the queue for review, and generates a review task to notify the operation and maintenance personnel. , operation and maintenance personnel view the details of abnormal data through the management interface, confirm the validity of the data after manual verification, complete the final data archiving process, continuously monitor the network connection status and automatically store the real-time collected data to the local SD card when the network is disconnected, to ensure that the measurement data is not lost during the network failure, and the data records contain device identifiers, high-precision timestamps and measurement values ​​and are stored in sequence, providing an accurate and orderly data basis for subsequent data processing and analysis. The breakpoint resumption mechanism after network recovery verifies data integrity and transmits unfinished data blocks in blocks based on the HTTP protocol, ensuring the continuity and integrity of data transmission. The cloud server's timestamp consistency check and abnormal identification and review mechanism can promptly detect and handle data timing anomalies to avoid erroneous data from entering the system. Compared with traditional phase meters, it greatly improves the reliability and accuracy of data transmission and management, and provides strong support for remote operation and maintenance and data management of power systems.

[0098] To further improve the offline module function, data encryption and disaster recovery functions can be added. Before the data is stored in the local SD card, advanced encryption algorithms (such as AES encryption) are used to encrypt the data to prevent data leakage during local storage due to SD card loss, theft, etc., thereby ensuring data security. At the same time, a data disaster recovery mechanism is set up in the local device to regularly back up the data in the SD card to the built-in solid-state drive or other storage media. When the SD card is damaged or encounters other failures, the data can be restored from the disaster recovery storage medium. In addition, on the cloud server side, in addition to the timestamp consistency check, multiple verification mechanisms for the data are added, such as verifying the integrity of the data through a hash algorithm, introducing a machine learning algorithm to detect abnormal behavior of the data, identify possible data tampering or abnormal fluctuations, and further improve data quality and security. A data visualization display function can also be added to the operation and maintenance management interface to intuitively present the distribution, trend and other information of abnormal data in the form of charts, making it convenient for operation and maintenance personnel to review and process data more efficiently.

[0099] In a preferred embodiment, the present invention can be further configured as follows: the system also includes a report generation module, which is a report template pre-set in accordance with the standards of the Southern Power Grid, including fields such as test time, voltage / current effective value, phase angle, power parameters and wiring judgment results; the generation function is triggered by the touch screen to automatically fill in the current measurement data into the template, and support exporting to PDF or Excel format, and use the SHA-256 algorithm to digitally sign the report file to ensure that the data cannot be tampered with. A report template that complies with the standards of the Southern Power Grid is pre-set to ensure that the report format is standardized and unified, meeting the professional requirements of the power industry, and automatically filling in the current measurement data into the template, simplifying the report generation process, improving work efficiency, avoiding errors that may occur when filling in manually, supporting exporting to PDF or Excel format, facilitating data viewing and further processing in different scenarios, and using the SHA-256 algorithm for digital signing to ensure the integrity and authenticity of the report data, preventing data from being tampered with, and providing reliable written materials for operation and maintenance, fault analysis, etc. of the power system, solving the problem of lack of standardized report generation and data security protection of traditional phase meters.

[0100] To further enhance the functionality of the report generation module, report customization and intelligent analysis functions can be added. In terms of customization, users are allowed to personalize report templates according to actual needs, such as adding specific project names, equipment numbers, tester information and other fields, and can also adjust the report layout, font style, etc. In terms of intelligent analysis, when the report is generated, the module automatically performs an in-depth analysis of the measurement data, such as calculating the fluctuation range of voltage and current, the changing trend of power factor, etc., and presents the analysis results in the form of charts in the report, while adding brief analysis instructions and suggestions to help users understand the power system operation status reflected by the measurement data more quickly and accurately. In addition, the report generation module can be integrated with the asset management system and fault diagnosis system of the power system. When the report is generated, it automatically associates the historical operation data and fault records of the relevant equipment to provide a more comprehensive basis for equipment status assessment and fault warning.

[0101] This low-power embedded mobile application platform is built around an ARM Cortex-A series processor, running a Linux operating system and a SQLite database, serving as the core system for coordinating the operations of various modules. The voltage acquisition module utilizes a voltage transformer, using the principle of electromagnetic induction to transmit the input three-phase high-voltage line voltage signal. This signal is then coupled to an isolated delta-sigma modulator via an output-side differential amplifier for electrical isolation and digital conversion. It intelligently switches between electromagnetic induction and optocoupler modes based on the input signal frequency, and an FPGA monitors the signal-to-noise ratio in real time to ensure signal quality. The current acquisition module utilizes a closed-loop Hall effect current sensor, based on the principle of magnetic balance, for contactless current measurement with automatic switching from 0.1A to 1000A. The measurement linearity error is ≤0.3%, and overcurrent protection circuitry provides protection against surges, overcurrent, and other anomalies. The data acquisition and processing module integrates a high-speed analog-to-digital converter and FPGA logic units to acquire instantaneous three-phase voltage and current values ​​in real time, calculate various electrical parameters using discrete Fourier transforms, and perform harmonic analysis. The wiring identification module uses a pre-stored characteristic phase table and a CT polarity compensation algorithm to determine wiring conditions and annotate them with a vector diagram. The data display module displays data in various modes via a 7-inch capacitive touchscreen, and its vector graphics generation method facilitates in-depth analysis. The remote collaboration module connects to the Alibaba Cloud platform via dual-band WiFi and the MQTT protocol, enabling data upload, storage, and multi-terminal access. The offline module ensures data storage and transmission during network anomalies. The report generation module provides pre-installed standard templates, automatically populates data, and supports export and digital signatures, providing standardized and reliable reports.

[0102] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0103] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A measurement and data processing system for an intelligent clamp-on load phase meter, characterized in that: include: A low-power embedded mobile application platform based on the ARM Cortex-A series processor, equipped with a Linux operating system and SQLite database, which coordinates the work of various system modules and performs data management, algorithm calculations and application control; The voltage acquisition module uses a voltage transformer based on the principle of electromagnetic induction. The input side is connected to the high-voltage line, and the output side is coupled with an isolated Δ-Σ modulator through a differential amplifier to achieve electrical isolation and digital conversion of the three-phase voltage signal. The current acquisition module uses a closed-loop Hall current sensor with a built-in magnetic ring and compensation coil to achieve non-contact current measurement through the principle of magnetic balance; The data acquisition and processing module integrates a 16-bit high-speed analog-to-digital converter and FPGA logic unit to collect the instantaneous values ​​of three-phase voltage and current in real time, and calculates the voltage amplitude, current amplitude, phase difference, frequency, active power, reactive power and power factor through discrete Fourier transform; The wiring identification module, based on six pre-stored characteristic phase tables, including standard phase and five incorrect wiring phases, combined with the CT polarity compensation algorithm, performs point-by-point error comparison between the measured current phase and the characteristic phase, automatically determining reverse polarity, incorrect phase sequence, or correct wiring, and dynamically marking the error points through a vector diagram.

2. The measurement and data processing system of the intelligent clamp-on phase meter according to claim 1, characterized in that: The multi-mode isolation switching method of the voltage acquisition module includes: Critical frequency calculation formula: ； in, is the equivalent inductance of the voltage transformer, For optocoupler coupling capacitance, when the input signal frequency When the electromagnetic induction mode is used, When the signal-to-noise ratio is less than 40dB, an alarm is triggered and the isolation module is reset.

3. The measurement and data processing system of the intelligent clamp-on phase meter according to claim 1, characterized in that: The harmonic analysis method of the data acquisition and processing module includes: Adaptive threshold filtering formula: ； in, is the fundamental amplitude, is the noise standard deviation of the first 10 harmonics; THD correction formula: ； in, is the sampling frequency, is the fundamental frequency, only The harmonic components of the signal are selected and the rest are treated as noise and removed.

4. The measurement and data processing system of the intelligent clamp-on phase meter according to claim 1, characterized in that: The current acquisition module also includes an overcurrent protection circuit, specifically including: Connect a transient voltage suppression diode in parallel at the output end of the sensor to absorb surge voltage; Adopting magnetic saturation detection circuit, when the primary current exceeds the upper limit of the range, the power supply of the compensation coil is automatically cut off and the sound and light alarm is triggered; Overcurrent event recording function, storing timestamp and peak current value in local Flash memory.

5. The measurement and data processing system of the intelligent clamp-on load phase meter according to claim 1, characterized in that: The phase compensation algorithm of the wiring discrimination module specifically includes the following steps: Polarity reverse compensation formula: ； in, The fixed phase difference caused by the transformer winding connection group number is pre-stored in the database through a table lookup method; Minimum circumference difference determination formula: ； in, There are six pre-stored characteristic phase values, namely 0°, 60°, 120°, 180°, 240°, and 300°. When the wiring is correct, Stability verification formula: ； in, is the number of measurement points for 10 consecutive power frequency cycles. Check that the wiring is stable.

6. The measurement and data processing system of the intelligent clamp-on load phase meter according to claim 1, characterized in that: The system also includes a data display module and a remote collaboration module; The data display module uses a 7-inch capacitive touch screen and supports three modes: waveform diagram, vector diagram and table. Users can customize the reference voltage channel and zoom or pan the waveform through gestures. The remote collaboration module has a built-in dual-band WiFi module and is connected to the Alibaba Cloud platform via the MQTT protocol, enabling real-time upload of measurement data, cloud storage, and simultaneous access by multiple terminals. It also supports remote triggering of measurement commands and report downloads.

7. The measurement and data processing system of the intelligent clamp-on load phase meter according to claim 6, characterized in that: The vector graph generation method of the data display module includes: Taking the phase A voltage as the reference, the normalized display amplitude is per unit length; Dynamic color mapping formula: ； in, This is the difference between the current phase and the reference voltage phase. When the user clicks the vector arrow, Fourier harmonic analysis is triggered, and a pop-up window displays the harmonic distortion rate and the amplitude ratios of the first five harmonics.

8. The measurement and data processing system of the intelligent clamp-on phase meter according to claim 6, characterized in that: The remote collaboration module is also provided with an offline module, which continuously monitors the network connection status for the system. When a network interruption is detected, the real-time collected voltage, current and phase data are automatically stored in a structured format to the local SD card. The data record contains a device identifier, a high-precision timestamp and a measurement value, and is stored in ascending order by timestamp. After the network is restored, the system starts the breakpoint resumption mechanism, first verifying the integrity of the local cached data, and then based on the block transmission function of the HTTP protocol, continues to upload the unfinished data block from the last successfully transmitted byte position to ensure the continuity and integrity of data transmission. After receiving the data, the cloud server performs a timestamp consistency check, adds an abnormal status mark to the data record with timing anomalies, including timestamp jumps, interval overruns, etc., and stores the abnormal data in the queue for review. At the same time, a review task is generated to notify the operation and maintenance personnel. The operation and maintenance personnel view the details of the abnormal data through the management interface, confirm the validity of the data after manual verification, and complete the final data archiving process.

9. The measurement and data processing system of the intelligent clamp-on load phase meter according to claim 1, characterized in that: The system also includes a report generation module, which is a pre-set report template that complies with the standards of the Southern Power Grid and includes fields such as test time, voltage / current effective value, phase angle, power parameters and wiring judgment results. The generation function is triggered by the touch screen to automatically fill the current measurement data into the template, and supports exporting to PDF or Excel format. The report file is digitally signed using the SHA-256 algorithm to ensure that the data cannot be tampered with.

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