Measurement verification method, system and equipment of voltage transformer and medium

Abstract

The invention discloses a measurement and verification method, system and device of a voltage transformer and a medium, and belongs to the field of electric power systems, and the method comprises the steps: carrying out the synchronous adjustment of the phase of a three-phase AC voltage according to a synchronous trigger signal, and inputting the synchronized three-phase AC voltage into a secondary side of a to-be-verified voltage transformer; performing signal sampling on the three-phase voltage of the primary side of the to-be-calibrated voltage transformer through the standard voltage sensor to obtain a three-phase analog voltage signal, and performing synchronous sampling on the three-phase analog voltage signal through the analog-to-digital converter according to the synchronous trigger signal to obtain a three-phase digital voltage signal; and determining a phase correction signal according to the phases of the three-phase digital voltage signal and the reference signal, and correcting the three-phase digital voltage signal according to the phase correction signal to realize measurement and verification of the voltage transformer. Therefore, through the implementation of the invention, the measurement verification of the voltage sensor can be realized, and the measurement accuracy is further improved.

Description

Technical Field

[0001] The present invention relates to the field of power systems, and in particular to a measurement and calibration method, system, equipment and medium for a voltage transformer. Background Art

[0002] In power systems, measuring the three-phase voltage and phase of 10kV potential transformers (PTs) is crucial for assessing PT operating conditions and neutral-point voltage drift. Traditional measurement methods typically employ a three-phase method, applying a balanced standard voltage to the PT simultaneously and measuring the voltage and phase of each phase in parallel. However, existing measurement systems suffer from low accuracy and are unable to accurately detect neutral-point voltage drift in 10kV PTs. Therefore, a measurement verification method has been proposed to improve the accuracy and reliability of 10kV PT measurements.

[0003] However, existing measurement and verification methods do not consider that due to the limited accuracy of three-phase power modules and differences in output circuits, the voltage signals output by the three-phase power supply may have slight phase asynchrony. This phase asynchrony can introduce measurement errors during the PT measurement process, thereby affecting the accurate judgment of the three-phase voltage balance state. At the same time, during the transmission of the voltage measurement signal, factors such as line transmission delays, poor contact, and electromagnetic interference can cause the phase of the collected three-phase voltage signal to change, resulting in phase error, thereby reducing the accuracy of phase measurement and verification. Summary of the Invention

[0004] The present invention provides a voltage transformer measurement and calibration method, system, device and medium, which can solve the existing measurement error and phase error problems, realize measurement and calibration of voltage sensors, and thus improve measurement accuracy.

[0005] The present invention provides a voltage transformer measurement and calibration method, comprising:

[0006] According to the synchronization trigger signal, the phase of the three-phase AC voltage is synchronously adjusted to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be verified;

[0007] The three-phase voltage of the primary side of the voltage transformer to be verified is sampled by a standard voltage sensor to obtain a three-phase analog voltage signal, and the three-phase analog voltage signal is synchronously sampled by an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal;

[0008] A phase correction signal is determined according to the phases of the three-phase digital voltage signal and a reference signal, and the three-phase digital voltage signal is corrected according to the phase correction signal to achieve measurement verification of the voltage transformer.

[0009] This embodiment of the present invention uses a synchronous trigger signal to synchronize the phases of the three-phase AC voltage, eliminating the phase asynchrony problem caused by module precision variations in traditional three-phase power supplies and ensuring highly consistent voltage phases at the PT secondary side. The synchronous trigger signal also controls the ADC to synchronously sample the three-phase analog voltage signals, eliminating phase errors introduced by sampling time deviations and improving the phase accuracy of the digital signal. Finally, the digital voltage signal is corrected by calculating a phase correction signal, directly addressing phase errors caused by signal transmission delays, electromagnetic interference, and other factors, significantly improving measurement accuracy.

[0010] Furthermore, the determining of the phase correction signal according to the phases of the three-phase digital voltage signal and the reference signal, and correcting the three-phase digital voltage signal according to the phase correction signal, is specifically as follows:

[0011] Using a digital phase-locked loop algorithm, calculating a phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain a target phase difference, wherein the reference signal is determined based on the digital voltage signal of any one phase in the three-phase digital voltage signal;

[0012] The phase correction signal is determined according to the target phase difference and the three-phase digital voltage signal, and the three-phase digital voltage signal is corrected by multiplying the three-phase digital voltage signal by the phase correction signal.

[0013] In this way, by taking any one of the three phases as a reference, the phases of the other two phases are dynamically adjusted to achieve phase self-calibration of the three-phase voltage signal and adapt to the phase synchronization requirements under different working conditions; phase correction is achieved through multiplication operation, which has a fast response speed and can eliminate dynamically changing phase errors in real time, ensuring the real-time and accuracy of the measurement results.

[0014] Furthermore, the digital phase-locked loop algorithm is used to calculate the phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain the target phase difference, specifically:

[0015] The digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal are discrete Fourier transformed, and the digital voltage signal and the reference signal after discrete Fourier transform are processed by an inverse tangent function to obtain the target phase difference.

[0016] In this way, the phase difference is accurately calculated by using discrete Fourier transform and inverse tangent function. Compared with traditional analog phase-locked loops, the digital algorithm has stronger anti-interference ability and higher phase correction accuracy.

[0017] Furthermore, after correcting the three-phase digital voltage signal according to the phase correction signal, the method further includes:

[0018] For each phase voltage of the corrected three-phase voltage, a root mean square algorithm is used to calculate the voltage amplitude of each phase voltage, and according to the difference between the voltage amplitude of each phase voltage and the preset amplitude, the voltage amplitude deviation of each phase voltage is calculated;

[0019] The phase difference of each phase voltage is calculated by the inverse tangent function of the two-phase voltage signals;

[0020] Comparing the magnitude relationship between the voltage amplitude deviation of each phase voltage and a preset amplitude deviation threshold, and comparing the magnitude relationship between the phase difference of each phase voltage and a preset phase difference threshold;

[0021] When the voltage amplitude deviation of any phase is greater than a preset amplitude deviation threshold, or the phase difference of any phase is greater than a preset phase difference threshold, it is determined that the corrected three-phase digital voltage signal is unbalanced, and an alarm signal is triggered.

[0022] This approach combines the RMS algorithm and the inverse tangent function to simultaneously evaluate voltage amplitude deviation and phase difference, comprehensively covering key parameters in PT measurement and improving calibration reliability. Preset amplitude deviation and phase difference thresholds automatically identify three-phase imbalance, reducing manual intervention and improving calibration efficiency. Imbalanced conditions trigger an alarm signal to promptly alert operators, preventing equipment failures caused by voltage imbalance and enhancing system safety.

[0023] Furthermore, the phase of the three-phase AC voltage is synchronously adjusted according to the synchronous trigger signal, specifically:

[0024] In response to the synchronous trigger signal, a single-phase AC voltage is obtained and subjected to a step-down, rectification and conversion process to obtain a DC voltage;

[0025] Processing the DC voltage through a three-phase variable frequency inverter to obtain the three-phase AC voltage;

[0026] monitoring the three-phase AC voltage in real time, comparing the three-phase AC voltage with the synchronization trigger signal, and determining whether the phases of the three-phase AC voltage are synchronized;

[0027] If they are not synchronized, the three-phase AC voltage is adjusted synchronously through a feedback regulation mechanism to achieve synchronous output of the three-phase AC voltage.

[0028] This feedback regulation mechanism adjusts the three-phase variable frequency inverter output in real time, ensuring strict synchronization of the three-phase AC voltage with the synchronization trigger signal, thus resolving the phase drift problem of traditional power supply output. Real-time monitoring and feedback regulation form a closed-loop control loop, improving the three-phase power supply's anti-interference capability and adapting to fluctuating grid conditions.

[0029] Furthermore, the three-phase voltage of the primary side of the voltage transformer to be verified is sampled by a standard voltage sensor to obtain a three-phase analog voltage signal, and according to the synchronization trigger signal, the three-phase analog voltage signal is synchronously sampled by an analog-to-digital converter to obtain a three-phase digital voltage signal, specifically:

[0030] Proportionally dividing the initial three-phase voltage signal obtained by sampling the voltage transformer to be calibrated to obtain a three-phase voltage signal;

[0031] Converting each phase voltage signal of the three-phase voltage signal into an analog electrical signal, and performing filtering and amplification processing on the analog electrical signal to obtain the three-phase analog voltage signal;

[0032] At each rising edge or falling edge of the synchronous trigger signal, the three channels of the analog-to-digital converter are started simultaneously to synchronously sample the three-phase analog voltage signal to obtain the three-phase digital voltage signal.

[0033] This proportionally divides the high-voltage signal through a capacitive voltage divider sensor, ensuring the safety of the sampling circuit while maintaining signal linearity. Simultaneously initiating sampling on all three ADC channels at the synchronous trigger signal edge avoids time skew between channels and eliminates phase errors introduced by asynchronous sampling. Filtering and amplification improve the analog signal-to-noise ratio, providing high-quality input for ADC conversion and further enhancing digital signal accuracy.

[0034] Furthermore, the voltage transformer measurement and verification method further includes:

[0035] The correction data is stored, and the correction data within a preset time period is analyzed and processed to generate a visual report and analysis curve.

[0036] This storage of correction data supports historical record query, facilitating fault analysis and performance evaluation. Visual reports and curves display long-term measurement data, helping to identify potential problems such as PT neutral point voltage drift and enabling preventive maintenance.

[0037] Another embodiment of the present invention further provides a voltage transformer measurement and verification system, comprising: a voltage synchronization module, a signal synchronization acquisition module, and a phase correction module;

[0038] The voltage synchronization module is used to synchronously adjust the phase of the three-phase AC voltage according to the synchronization trigger signal, so as to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be verified;

[0039] The signal synchronization acquisition module is used to sample the three-phase voltage of the primary side of the voltage transformer to be verified through a standard voltage sensor to obtain a three-phase analog voltage signal, and synchronously sample the three-phase analog voltage signal through an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal;

[0040] The phase correction module is used to determine a phase correction signal according to the phase of the three-phase digital voltage signal and the reference signal, and correct the three-phase digital voltage signal according to the phase correction signal to achieve measurement verification of the voltage transformer.

[0041] This embodiment of the present invention uses a synchronous trigger signal to synchronize the phases of the three-phase AC voltage, eliminating the phase asynchrony problem caused by module precision variations in traditional three-phase power supplies and ensuring highly consistent voltage phases at the PT secondary side. The synchronous trigger signal also controls the ADC to synchronously sample the three-phase analog voltage signals, eliminating phase errors introduced by sampling time deviations and improving the phase accuracy of the digital signal. Finally, the digital voltage signal is corrected by calculating a phase correction signal, directly addressing phase errors caused by signal transmission delays, electromagnetic interference, and other factors, significantly improving measurement accuracy.

[0042] Another embodiment of the present invention further provides a terminal device, comprising: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the steps of the voltage transformer measurement and verification method of the present invention are implemented.

[0043] Another embodiment of the present invention further provides a computer-readable storage medium item, comprising: a stored computer program, which controls the device where the computer-readable storage medium is located to execute the steps of the voltage transformer measurement and verification method of the present invention when the computer program is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 This is a schematic structural diagram of a voltage transformer measurement and verification system provided by an embodiment of the present invention;

[0046] Figure 2 This is a flow chart of a voltage transformer measurement and calibration method provided by an embodiment of the present invention;

[0047] Figure 3 1 is a flow chart of a phase correction step provided by an embodiment of the present invention;

[0048] Figure 4 This is a flow chart of a three-phase voltage balance determination step provided by an embodiment of the present invention;

[0049] Figure 5 It is a structural diagram of another voltage transformer measurement and verification system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0053] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0057] For the convenience of description, before describing the method embodiment, a structural diagram of a voltage transformer measurement and verification system is first proposed, as shown in FIG. Figure 1 As shown, the system includes: a clock source module, a synchronization trigger signal generation module, a three-phase power generation module, a signal acquisition module, a phase-locked loop phase calibration module, a central processing unit, a display and alarm module, and a data storage module;

[0058] The clock source module is used to provide an accurate clock signal as a synchronization reference for the entire system. The module can use a highly stable crystal oscillator to output a clock signal with high frequency stability. The clock source module referred to in this embodiment of the present invention is:

[0059] The synchronous trigger signal generation module is used to generate a synchronous trigger signal according to the clock signal of the clock source module, and is used to control the output of the three-phase power supply and the sampling action of the signal acquisition module. This module can ensure that the output of the three-phase power supply and the sampling of the signal acquisition module are synchronized;

[0060] The three-phase power generation module is used to convert a single-phase input power supply into a three-phase balanced AC voltage and adjust the phase of the output voltage according to the synchronization trigger signal to ensure the synchronous output of the three-phase voltage signal. The module adopts AC-DC-AC inverter technology to first step down and rectify the input single-phase 220V AC power supply into a DC voltage, and then generate a three-phase AC voltage with precise frequency through a three-phase variable frequency inverter;

[0061] The signal acquisition module includes a three-channel standard voltage sensor and an ADC converter, which is used to collect three-phase voltage signals and convert them into digital signals. The standard voltage sensor adopts a capacitive voltage divider voltage sensor, which can accurately measure voltage signals. The ADC converter adopts synchronous sampling technology to ensure simultaneous sampling of the three-phase voltage signals.

[0062] The phase-locked loop (PLL) phase calibration module is used to perform phase correction on the collected three-phase voltage signal to eliminate phase error. The module uses a digital phase-locked loop algorithm to generate a phase correction signal by comparing the phase difference between the input signal and the reference signal, and adjusts the phase of the input signal;

[0063] The central processing unit (CPU) is used to control the entire system, process and analyze data, and further process and analyze the digital signals output by the signal acquisition module and the PLL phase calibration module to calculate the amplitude and phase difference of the three-phase voltage and determine whether the three-phase voltage is balanced;

[0064] The display and alarm module is used to display the measurement results and system status, and to issue an alarm signal when an abnormal situation occurs. The module uses an LCD display screen that can clearly display information such as the amplitude, phase difference, and balance status of the three-phase voltage; and is also equipped with an audible and visual alarm that issues an alarm signal when a connection error occurs or the measurement result exceeds a set threshold.

[0065] See also Figure 2 In order to solve the measurement error and phase error problems of voltage transformers in the prior art, an embodiment of the present invention provides a voltage transformer measurement and calibration method, which is applied in Figure 1 Taking the system structure shown in FIG. 1 as an example, the method includes steps S201 to S203, which are specifically as follows:

[0066] Step S201: According to a synchronization trigger signal, the phase of the three-phase AC voltage is synchronously adjusted to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be calibrated.

[0067] In this embodiment, the three-phase power supply generation module responds to the synchronization trigger signal to generate a three-phase AC voltage. However, due to the limited accuracy of the three-phase power supply generation module and the differences in the output circuit, the three-phase AC voltage output by the three-phase power supply generation module may have a phase error. Therefore, the three-phase power supply generation module compares the phase of the three-phase AC voltage output by the synchronization trigger signal and the three-phase power supply, and adjusts the output phase through a feedback regulation mechanism to achieve phase synchronization and accuracy of the three-phase AC voltage; the three-phase power supply generation module sends the synchronized three-phase AC voltage to the secondary side of the voltage transformer to be calibrated, providing a stable three-phase voltage for the voltage transformer to be calibrated.

[0068] As an example of an embodiment of the present invention, before synchronously adjusting the phase of the three-phase AC voltage according to the synchronous trigger signal, the method includes: performing system initialization processing.

[0069] In this embodiment, the 10kV PT neutral point voltage drift device is powered on, and the central processing unit (CPU) and various functional modules are started. After the clock source module begins operating, it generates a clock signal and sends it to the synchronization trigger signal generation module. The synchronization trigger signal generation module generates a synchronization trigger signal based on the received clock signal. The CPU initializes various module parameters, including the sampling frequency and resolution of the analog-to-digital converter (ADC) and the initial phase parameters of the phase-locked loop (PLL) phase calibration module. The CPU also initializes the display and alarm module, clears any remaining information on the display, and prepares to receive and display new measurement results.

[0070] As an example of an embodiment of the present invention, the phase of the three-phase AC voltage is synchronously adjusted according to the synchronous trigger signal, specifically: in response to the synchronous trigger signal, a single-phase AC voltage is obtained for step-down, rectification and conversion processing to obtain a DC voltage; the DC voltage is processed by a three-phase variable frequency inverter to obtain the three-phase AC voltage; the three-phase AC voltage is monitored in real time, and the three-phase AC voltage is compared with the synchronous trigger signal to determine whether the phase of the three-phase AC voltage is synchronized; if not synchronized, the three-phase AC voltage is synchronously adjusted through a feedback regulation mechanism to achieve synchronous output of the three-phase AC voltage.

[0071] In this embodiment, after receiving the synchronization trigger signal, the three-phase power supply generation module starts working, steps down and rectifies the input single-phase 220V AC power supply to convert it into a DC voltage, and then generates a three-phase AC voltage with precise frequency through a three-phase frequency conversion inverter; the control circuit inside the three-phase power supply generation module monitors the phase of the output three-phase AC voltage in real time and compares it with the synchronization trigger signal. If the phase is not synchronized, the output phase of the three-phase frequency conversion inverter is adjusted to ensure the synchronous output of the three-phase AC voltage by the three-phase power supply generation module; the output three-phase AC voltage is connected to the A, B, and C three-phase secondary winding terminals of the PT through corresponding connecting lines, so that the secondary side of the PT obtains a stable three-phase AC voltage input of a certain amplitude.

[0072] Step S202: Using a standard voltage sensor, sample the three-phase voltage on the primary side of the voltage transformer to be calibrated to obtain a three-phase analog voltage signal, and according to the synchronization trigger signal, synchronously sample the three-phase analog voltage signal through an analog-to-digital converter to obtain a three-phase digital voltage signal.

[0073] In this embodiment, the standard voltage sensor in the signal acquisition module samples the three-phase AC voltage on the primary side of the PT to obtain a three-phase analog voltage signal. Under the control of the synchronous trigger signal, the analog-to-digital converter synchronously samples the three-phase analog voltage signal and converts the analog signal into a digital signal to obtain a three-phase digital voltage signal. The collected three-phase digital voltage signal is then sent to the CPU.

[0074] As an example of an embodiment of the present invention, the three-phase voltage on the primary side of the voltage transformer to be calibrated is sampled by a standard voltage sensor to obtain a three-phase analog voltage signal, and the three-phase analog voltage signal is synchronously sampled by an analog-to-digital converter according to the synchronous trigger signal to obtain a three-phase digital voltage signal. Specifically, the initial three-phase voltage signal obtained by sampling the voltage transformer to be calibrated is proportionally divided to obtain a three-phase voltage signal; each phase voltage signal in the three-phase voltage signal is converted into an analog electrical signal, and the analog electrical signal is filtered and amplified to obtain the three-phase analog voltage signal; at each rising edge or falling edge of the synchronous trigger signal, the three channels of the analog-to-digital converter are simultaneously started, and the three-phase analog voltage signal is synchronously sampled to obtain the three-phase digital voltage signal.

[0075] In this embodiment, three-channel standard voltage sensors simultaneously sample the three-phase voltage on the primary side of the PT, proportionally divide the sampled initial three-phase voltage signal to obtain a three-phase voltage signal; convert the three-phase voltage signal into an analog electrical signal, filter and amplify the analog electrical signal to obtain the three-phase analog voltage signal; input the three-phase analog voltage signal into an ADC converter, and under the control of the synchronous trigger signal, the ADC converter simultaneously starts the three channels of the ADC converter at each rising edge or falling edge of the synchronous trigger signal, synchronously samples the three-phase analog voltage signal, converts the analog signal into a digital signal, obtains the three-phase digital voltage signal, and sends the three-phase digital voltage signal to the CPU.

[0076] Step S203: determining a phase correction signal according to the phases of the three-phase digital voltage signal and the reference signal, and correcting the three-phase digital voltage signal according to the phase correction signal to achieve measurement verification of the voltage transformer.

[0077] In this embodiment, after the CPU receives the three-phase digital voltage signal, it sends it to the phase-locked loop phase calibration module. The phase-locked loop phase calibration module adopts a digital phase-locked loop algorithm to calculate according to the phase of the three-phase digital voltage signal and the reference signal to obtain a phase correction signal, and performs phase correction on the input three-phase digital voltage signal to realize the measurement verification of the voltage transformer.

[0078] As an example of an embodiment of the present invention, the phase correction signal is determined according to the phase of the three-phase digital voltage signal and the reference signal, and the three-phase digital voltage signal is corrected according to the phase correction signal. Specifically, a digital phase-locked loop algorithm is used to calculate the phase difference of the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain a target phase difference, wherein the reference signal is determined according to any one phase digital voltage signal in the three-phase digital voltage signal; the phase correction signal is determined according to the target phase difference and the three-phase digital voltage signal, and the correction of the three-phase digital voltage signal is achieved by multiplying the three-phase digital voltage signal by the phase correction signal.

[0079] In this embodiment, if Figure 3 The flowchart of a phase correction step shown in the figure adopts a digital phase-locked loop algorithm to calculate the phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain a target phase difference. In practical applications, the voltage signal of one phase of the three-phase voltage signal can be selected as the reference signal, for example, the voltage signal of phase A can be selected as the reference signal. By calculating and correcting the phase difference between the three-phase voltage signal of each phase and the reference signal, the phase consistency of the three-phase voltage signal is ensured. The phase correction signal is determined according to the target phase difference and the three-phase digital voltage signal, and the correction of the three-phase digital voltage signal is achieved by multiplying the three-phase digital voltage signal by the phase correction signal. The calculation formula of the phase correction signal is expressed as follows:

[0080] y(n)=x(n)·e -jφ(n) ;

[0081] Among them, x(n) is the three-phase digital voltage signal, is the phase difference, and y(n) is the phase correction signal.

[0082] As an example of an embodiment of the present invention, the digital phase-locked loop algorithm is used to calculate the phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain the target phase difference. Specifically, the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal are discrete Fourier transformed, and the digital voltage signal and the reference signal after discrete Fourier transformation are processed by the inverse tangent function to obtain the target phase difference.

[0083] In this embodiment, the target phase difference is calculated as follows:

[0084]

[0085] Wherein, x(n) is the three-phase digital voltage signal, r(n) is the reference signal, X(n) and R(n) are the discrete Fourier transform results of the three-phase digital voltage signal and the reference signal, respectively.

[0086] As an example of an embodiment of the present invention, after the three-phase digital voltage signal is corrected according to the phase correction signal, it also includes: for each phase voltage of the corrected three-phase voltage, using the root mean square algorithm to calculate the voltage amplitude of each phase voltage, and calculating the voltage amplitude deviation of each phase voltage based on the difference between the voltage amplitude of each phase voltage and the preset amplitude; calculating the phase difference of each phase voltage by the inverse tangent function of the two-phase voltage signal; comparing the magnitude relationship between the voltage amplitude deviation of each phase voltage and the preset amplitude deviation threshold, and comparing the magnitude relationship between the phase difference of each phase voltage and the preset phase difference threshold; when the voltage amplitude deviation of any phase is greater than the preset amplitude deviation threshold, or the phase difference of any phase is greater than the preset phase difference threshold, it is determined that the corrected three-phase digital voltage signal is unbalanced, and an alarm signal is triggered.

[0087] In this embodiment, if Figure 4 The figure shows a flow chart of the steps for determining three-phase voltage balance. The CPU further processes and analyzes the corrected three-phase voltage signals to calculate the voltage amplitude and phase difference of each phase voltage. The voltage amplitude can be calculated using the root mean square (RMS) algorithm. The calculation formula is as follows:

[0088]

[0089] Among them, v(n) is the instantaneous value of the sampled voltage, and N is the number of sampling points.

[0090] The phase difference is obtained by calculating the inverse tangent function of the two-phase voltage signals. The calculation formula is as follows:

[0091]

[0092] Where V is the discrete Fourier transform result of each phase voltage signal.

[0093] Based on the calculated three-phase voltage amplitudes and phase differences, the system determines whether the three-phase voltages are balanced. Voltage amplitude deviation and phase difference thresholds are set. When the voltage amplitude deviation or phase difference of any phase exceeds the set thresholds, the three-phase voltages are determined to be unbalanced, and an alarm signal is triggered. During the process of determining whether the three-phase voltages are balanced, the CPU also performs statistical analysis on the measurement results, calculating statistical parameters such as the average and standard deviation of multiple measurements to assess the stability and reliability of the measurement results. Furthermore, the CPU transmits the measurement results, such as the three-phase voltage amplitudes, phase differences, and balance status, to the display and alarm module. The display and alarm module visually displays the measurement results on an LCD screen, allowing system operators to intuitively view the balance status of the three-phase voltages. If the three-phase voltages are determined to be unbalanced, the display and alarm module issues an alarm signal, such as an audible or visual alarm, to alert the system operator to take prompt action. Furthermore, if the current and voltage parameters are abnormal, or if the phase relationship deviates from the normal value range by exceeding preset thresholds, a second alarm signal is triggered, alerting the system operator to problems such as incorrectly connected high-voltage cables. The type and mode of the alarm signal can be customized according to the user's preferences and actual needs. For example, different alarm sound and light color combinations can be set to distinguish different types of misconnection situations, further improving the effectiveness and intuitiveness of the alarm.

[0094] As an example of an embodiment of the present invention, the voltage transformer measurement and verification method further includes:

[0095] The correction data is stored, and the correction data within a preset time period is analyzed and processed to generate a visual report and analysis curve.

[0096] In this embodiment, the CPU stores and records the data obtained from each measurement, such as the three-phase voltage amplitude, phase difference, and measurement time, in memory. System operators can access this stored data through the system's visual interface or external interfaces, such as a USB port, for subsequent analysis and processing, enabling long-term monitoring and evaluation of the 10kV PT's operating status. The stored data can also be used to generate visual reports and analysis curves, helping operators more intuitively understand the operating trends and changes of the 10kV PT.

[0097] The embodiments of the present invention achieve synchronous acquisition of three-phase voltage signals through the control of a clock source and a synchronous trigger signal, eliminating measurement errors caused by phase asynchrony. A phase-locked loop (PLL) phase calibration algorithm is used to phase-correct the acquired signals, further improving the accuracy of phase measurement and achieving a three-phase voltage measurement accuracy of less than 3%. Phase correction of the voltage signals output by the three-phase power supply eliminates phase errors caused by factors such as unstable power output and signal transmission delays, improving the reliability of measurement results and enabling more accurate detection of neutral point voltage drift in 10kV PTs, effectively ensuring the stable operation of the power system. The entire measurement process is highly automated; operators only need to follow the prescribed steps to connect the equipment and start the measurement. The system automatically completes signal acquisition, phase correction, data analysis, and result display, reducing operational complexity and improving work efficiency. The system can monitor the balance of the three-phase voltages in real time and promptly issue an alarm signal when an abnormality occurs, prompting the operator to take appropriate measures. This effectively prevents faults caused by voltage imbalance and ensures the safe operation of power equipment.

[0098] like Figure 5 As shown, based on the above method embodiment, a corresponding system embodiment is provided; an embodiment of the present invention provides another voltage transformer measurement and verification system 500, including: a voltage synchronization module 501, a signal synchronization acquisition module 502 and a phase correction module 503;

[0099] The voltage synchronization module 501 is used to synchronously adjust the phase of the three-phase AC voltage according to the synchronization trigger signal, so as to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be verified;

[0100] The signal synchronization acquisition module 502 is used to sample the three-phase voltage of the primary side of the voltage transformer to be verified through a standard voltage sensor to obtain a three-phase analog voltage signal, and synchronously sample the three-phase analog voltage signal through an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal;

[0101] The phase correction module 503 is configured to determine a phase correction signal according to the phases of the three-phase digital voltage signal and a reference signal, and to correct the three-phase digital voltage signal according to the phase correction signal to achieve measurement verification of the voltage transformer.

[0102] It can be understood that the above-mentioned system embodiment corresponds to the method embodiment of the present invention, which can implement the measurement and verification method of the voltage transformer provided by any of the above-mentioned method embodiments of the present invention.

[0103] It should be noted that the system embodiments described above are merely illustrative, and some or all of the modules may be selected to achieve the objectives of the present embodiments as needed. Furthermore, in the drawings of the system embodiments provided herein, the connection relationships between modules indicate that they have communication connections, which may be implemented as one or more communication buses or signal lines. Persons of ordinary skill in the art can understand and implement the present invention without inventive effort.

[0104] Based on the above-mentioned embodiment of the voltage transformer measurement and verification method, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the voltage transformer measurement and verification method of any embodiment of the present invention is implemented.

[0105] For example, in this embodiment, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to implement the present invention. The one or more module elements may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0106] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0107] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device using various interfaces and lines.

[0108] Based on the above-mentioned method embodiments, another embodiment of the present invention provides a computer-readable storage medium, including a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the voltage transformer measurement and verification method described in any one of the above-mentioned method embodiments of the present invention.

[0109] Wherein, the module / unit integrated in the system / terminal device, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or system that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0110] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for measuring and verifying a voltage transformer, characterized in that: include: According to the synchronization trigger signal, the phase of the three-phase AC voltage is synchronously adjusted to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be verified; The three-phase voltage of the primary side of the voltage transformer to be verified is sampled by a standard voltage sensor to obtain a three-phase analog voltage signal, and the three-phase analog voltage signal is synchronously sampled by an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal; A phase correction signal is determined according to the phases of the three-phase digital voltage signal and a reference signal, and the three-phase digital voltage signal is corrected according to the phase correction signal to achieve measurement verification of the voltage transformer.

2. The voltage transformer measurement and calibration method according to claim 1, wherein: The determining of a phase correction signal according to the phases of the three-phase digital voltage signal and a reference signal, and correcting the three-phase digital voltage signal according to the phase correction signal, is specifically as follows: Using a digital phase-locked loop algorithm, calculating a phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain a target phase difference, wherein the reference signal is determined based on the digital voltage signal of any one phase in the three-phase digital voltage signal; The phase correction signal is determined according to the target phase difference and the three-phase digital voltage signal, and the three-phase digital voltage signal is corrected by multiplying the three-phase digital voltage signal by the phase correction signal.

3. The voltage transformer measurement and calibration method according to claim 2, characterized in that: The digital phase-locked loop algorithm is used to calculate the phase difference between the digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal to obtain the target phase difference, specifically: The digital voltage signal of each phase in the three-phase digital voltage signal and the reference signal are discrete Fourier transformed, and the digital voltage signal and the reference signal after discrete Fourier transform are processed by an inverse tangent function to obtain the target phase difference.

4. The voltage transformer measurement and calibration method according to claim 1, wherein: After correcting the three-phase digital voltage signal according to the phase correction signal, the method further includes: For each phase voltage of the corrected three-phase voltage, a root mean square algorithm is used to calculate the voltage amplitude of each phase voltage, and according to the difference between the voltage amplitude of each phase voltage and the preset amplitude, the voltage amplitude deviation of each phase voltage is calculated; The phase difference of each phase voltage is calculated by the inverse tangent function of the two-phase voltage signals; Comparing the magnitude relationship between the voltage amplitude deviation of each phase voltage and a preset amplitude deviation threshold, and comparing the magnitude relationship between the phase difference of each phase voltage and a preset phase difference threshold; When the voltage amplitude deviation of any phase is greater than a preset amplitude deviation threshold, or the phase difference of any phase is greater than a preset phase difference threshold, it is determined that the corrected three-phase digital voltage signal is unbalanced, and an alarm signal is triggered.

5. The voltage transformer measurement and calibration method according to claim 1, wherein: The phase of the three-phase AC voltage is synchronously adjusted according to the synchronous trigger signal, specifically: In response to the synchronous trigger signal, a single-phase AC voltage is obtained and subjected to a step-down, rectification and conversion process to obtain a DC voltage; Processing the DC voltage through a three-phase variable frequency inverter to obtain the three-phase AC voltage; monitoring the three-phase AC voltage in real time, comparing the three-phase AC voltage with the synchronization trigger signal, and determining whether the phases of the three-phase AC voltage are synchronized; If they are not synchronized, the three-phase AC voltage is adjusted synchronously through a feedback regulation mechanism to achieve synchronous output of the three-phase AC voltage.

6. The voltage transformer measurement and calibration method according to claim 1, wherein: The three-phase voltage of the primary side of the voltage transformer to be verified is sampled by a standard voltage sensor to obtain a three-phase analog voltage signal, and the three-phase analog voltage signal is synchronously sampled by an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal, specifically: Proportionally dividing the initial three-phase voltage signal obtained by sampling the voltage transformer to be calibrated to obtain a three-phase voltage signal; Converting each phase voltage signal of the three-phase voltage signal into an analog electrical signal, and performing filtering and amplification processing on the analog electrical signal to obtain the three-phase analog voltage signal; At each rising edge or falling edge of the synchronous trigger signal, the three channels of the analog-to-digital converter are started simultaneously to synchronously sample the three-phase analog voltage signal to obtain the three-phase digital voltage signal.

7. The voltage transformer measurement and calibration method according to claim 4, characterized in that: Also includes: The correction data is stored, and the correction data within a preset time period is analyzed and processed to generate a visual report and analysis curve.

8. A voltage transformer measurement and calibration system, characterized in that: include: Voltage synchronization module, signal synchronization acquisition module and phase correction module; The voltage synchronization module is used to synchronously adjust the phase of the three-phase AC voltage according to the synchronization trigger signal, so as to input the synchronized three-phase AC voltage into the secondary side of the voltage transformer to be verified; The signal synchronization acquisition module is used to sample the three-phase voltage of the primary side of the voltage transformer to be verified through a standard voltage sensor to obtain a three-phase analog voltage signal, and synchronously sample the three-phase analog voltage signal through an analog-to-digital converter according to the synchronization trigger signal to obtain a three-phase digital voltage signal; The phase correction module is used to determine a phase correction signal according to the phase of the three-phase digital voltage signal and the reference signal, and correct the three-phase digital voltage signal according to the phase correction signal to achieve measurement verification of the voltage transformer.

9. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for measuring and verifying a voltage transformer according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that include: A stored computer program, wherein when the computer program is run, the device where the computer-readable storage medium is located is controlled to execute the voltage transformer measurement and verification method according to any one of claims 1 to 7.

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