A detection system and method for an electronic transformer tester

Abstract

The present application is applicable to the technical field of electronic transformers, and provides a detection system and method for an electronic transformer tester, the system comprising: a signal generator, for performing digital-to-analog conversion on stored preset waveform data having a preset frequency and a preset number of sampling points to generate an initial analog signal, and outputting a synchronization pulse signal at the starting position of the first rising edge of the first waveform period of the preset waveform data to synchronize the signal generator with the clock of the electronic transformer tester; a low-pass filter, for filtering the initial analog signal to obtain an analog signal; a sinusoidal wave sampling value message generator, for generating a standard data message according to the analog initial phase value of the analog signal, so that the electronic transformer tester compares the actual measured phase error value obtained by processing the analog signal and the standard data message with the preset phase error standard value, determines the detection error value, and improves the angular difference traceability accuracy of the electronic transformer tester.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic transformers, and in particular, relates to a detection system and method for an electronic transformer tester. Background Art

[0002] At present, the ratio difference traceability of electronic transformers is relatively simple, which can be achieved through the standard source method, standard table method, or differential sampling based on programmable Josephson voltage standard (PJVS) and Josephson arbitrary waveform synthesizer (JAWS). However, the angular difference of electronic transformers requires the establishment of a standard signal with the same analog and digital source, and the angular difference traceability is more difficult. The electronic transformer tester is a device used to detect the performance and accuracy of electronic transformers. It can calibrate the output signal of the transformer to ensure the accuracy of its measurement results. Therefore, the angular difference traceability of the electronic transformer tester is the key to the traceability of electronic transformers.

[0003] There are two main methods for tracing the angle difference of electronic transformer testers: the triggered square wave sampling method and the zero-crossing method. The triggered square wave sampling method is limited by the delays such as the sampling / holding time and integration time of analog-to-digital sampling, and can achieve an accuracy level of 0.01, that is, a theoretical angle difference traceability of about 0.3 minutes. The zero-crossing method is limited by the signal-to-noise ratio and speed of the comparator, and the zero-crossing signal will jitter, and can only obtain an accuracy of about 0.6us, that is, the accuracy level is 0.02. Therefore, the existing tracing method for the angle difference of electronic transformer testers has the problem of low traceability accuracy. Summary of the invention

[0004] The embodiments of the present application provide a detection system and method for an electronic transformer calibrator, which can solve the problem of low tracing accuracy of the angle difference tracing method of the existing electronic transformer calibrator.

[0005] In a first aspect, an embodiment of the present application provides a detection system for an electronic transformer tester, the system comprising:

[0006] Signal generator, low-pass filter, sine wave sampling value message generator, among which,

[0007] The signal generator is used to store a plurality of preset waveform data, and to perform digital-to-analog conversion on the stored preset waveform data having a preset frequency and a preset number of sampling points, so as to generate an initial analog signal for detecting the electronic transformer tester;

[0008] The signal generator comprises a synchronization pulse output module, which is used to output a synchronization pulse signal through the synchronization pulse output module at the starting position of the first rising edge of the first waveform period of the preset waveform data; and output the synchronization pulse signal to the synchronization pulse receiving module in the electronic transformer tester, so that the signal generator is synchronized with the clock of the electronic transformer tester;

[0009] The low-pass filter is connected to the signal generator and the analog signal terminal of the electronic transformer tester, respectively, and is used to filter the initial analog signal generated by the signal generator to obtain an analog signal, and input the analog signal from the analog signal terminal to the electronic transformer tester;

[0010] The sine wave sampling value message generator is connected to the data message terminal of the electronic transformer tester, and is used to generate a standard data message according to the simulated initial phase value of the analog signal, and input the standard data message from the data message terminal to the electronic transformer tester, so that the electronic transformer tester processes the analog signal and the standard data message to obtain a measured value of the phase error, and compares the measured value of the phase error with a preset standard value of the phase error to determine the detection error value of the electronic transformer tester.

[0011] In a possible implementation of the first aspect, the signal generator includes a waveform memory, a digital signal processor, and a digital-to-analog converter; wherein,

[0012] The waveform memory is used to store a plurality of the preset waveform data; wherein the preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data;

[0013] The digital signal processor is connected to the waveform memory and the digital-to-analog converter respectively, and is used to read the preset square wave data having the preset frequency and the preset number of sampling points in the waveform memory, and overlap the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data to determine the starting position of the preset square wave data;

[0014] The digital signal processor is further configured to, after determining the starting position of the preset square wave data, read the preset step wave data having the preset frequency and the preset number of sampling points in the waveform memory, so as to replace the preset square wave data with the preset step wave data, and send the preset step wave data to the digital-to-analog converter at a preset sending rate;

[0015] The digital-to-analog converter is connected to the low-pass filter and is used to perform digital-to-analog conversion on the preset step wave data sent by the data signal processor to obtain the initial analog signal.

[0016] In a possible implementation manner of the first aspect, the analog initial phase value of the analog signal is the sum of a first phase value of the initial analog signal and a second phase lag value generated after the initial analog signal is processed by the low-pass filter.

[0017] In a possible implementation manner of the first aspect, the first phase value of the initial analog signal is determined according to the preset number of sampling points and a preset fundamental phase calculation formula; wherein the preset fundamental phase calculation formula is:

[0018] ;

[0019] in, represents the first phase value, and N represents the preset number of sampling points.

[0020] In a possible implementation manner of the first aspect, the low-pass filter includes a first-stage low-pass filter and a first operational amplifier; wherein,

[0021] The first-stage low-pass filter comprises a first resistor and a first capacitor, and is used to filter the high-frequency component in the initial analog signal to obtain a filtered analog signal;

[0022] The first operational amplifier is used to perform signal amplification processing on the filtered analog signal to obtain the analog signal.

[0023] In a possible implementation manner of the first aspect, the second phase lag value is determined according to the first resistor, the first capacitor, and a preset phase shift calculation formula; wherein the preset phase shift calculation formula is:

[0024]

[0025] in, represents the second phase lag value, f represents the preset frequency, represents the resistance value of the first resistor, represents the capacitance value of the first capacitor.

[0026] In a possible implementation of the first aspect, the accuracy level of the low-pass filter is 0.3ppm-0.4ppm, the accuracy level of the sine wave sampling value message generator is 0.9ppm-1ppm, and the accuracy level of the signal generator is 9ppm-10ppm.

[0027] In a possible implementation manner of the first aspect, the electronic transformer tester processes the analog signal and the standard data message to obtain a measured value of the phase error, including:

[0028] The analog signal terminal of the electronic transformer tester receives the analog signal, and the data message terminal of the electronic transformer tester receives the standard data message;

[0029] Performing analog-to-digital conversion on the analog signal and extracting the initial phase of the analog signal to obtain a measured initial phase value of the analog signal;

[0030] The measured initial phase value of the analog signal is calculated to differ from the standard initial phase value of the standard data message to obtain the actual measured value of the phase error; wherein the standard initial phase value of the standard data message is determined by the analog initial phase value of the analog signal.

[0031] In a second aspect, an embodiment of the present application provides a detection method of an electronic transformer tester, which uses a detection system of the electronic transformer tester as described in any one of the above items for detection, including:

[0032] The preset waveform data with a preset frequency and a preset number of sampling points stored therein is converted by a signal generator into digital-to-analog form to generate an initial analog signal for detecting the electronic transformer tester;

[0033] At the starting position of the first rising edge of the first waveform period of the preset waveform data, a synchronization pulse signal is output through a synchronization pulse output module in the signal generator, and the synchronization pulse signal is output to a synchronization pulse receiving module in the electronic transformer tester, so that the signal generator is synchronized with the clock of the electronic transformer tester;

[0034] Filtering the initial analog signal generated by the signal generator through a low-pass filter to obtain an analog signal, and inputting the analog signal from the analog signal terminal to the electronic transformer tester;

[0035] Generate a standard data message according to the simulated initial phase value of the analog signal through a sine wave sampling value message generator, and input the standard data message from the data message terminal to the electronic transformer tester;

[0036] The analog signal and the standard data message are processed by the electronic transformer tester to obtain a measured value of the phase error;

[0037] The phase error actual measured value is compared with a preset phase error standard value to determine the detection error value of the electronic transformer tester.

[0038] In a possible implementation manner of the second aspect, the preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data;

[0039] The method of converting the stored preset waveform data with a preset frequency and a preset number of sampling points by a signal generator to generate an initial analog signal for detecting the electronic transformer tester includes:

[0040] Reading the preset square wave data having the preset frequency and the preset number of sampling points stored in the waveform memory in the signal generator, and overlapping the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data to determine the starting position of the preset square wave data;

[0041] After determining the starting position of the preset square wave data, reading the preset step wave data having the preset frequency and the preset number of sampling points stored in the waveform memory to replace the preset square wave data with the preset step wave data, and sending the preset step wave data to the digital-to-analog converter in the signal generator at a preset sending rate;

[0042] The preset step wave data is converted into digital-to-analog format by the digital-to-analog converter to obtain the initial analog signal.

[0043] In a third aspect, an embodiment of the present application provides a terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the detection method of the electronic transformer tester described in any one of the above items when executing the computer program.

[0044] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the detection method of the electronic transformer tester described in any one of the above items is implemented.

[0045] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the terminal device to execute the detection method of the electronic transformer tester described in any one of the above-mentioned first aspects.

[0046] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0047] The embodiment of the present application provides a detection system for an electronic transformer tester, the detection system comprising: a signal generator, a low-pass filter, and a sine wave sampling value message generator, wherein the signal generator is used to store a plurality of preset waveform data, and perform digital-to-analog conversion on the stored preset waveform data with a preset frequency and a preset number of sampling points to generate an initial analog signal for detecting the electronic transformer tester; the signal generator comprises a synchronous pulse output module, which is used to output a synchronous pulse signal through the synchronous pulse output module at the starting position of the first rising edge of the first waveform period of the preset waveform data; and output the synchronous pulse signal to the synchronous pulse receiving module in the electronic transformer tester, so that the signal generator and the clock of the electronic transformer tester are synchronized. step; a low-pass filter is respectively connected to the analog signal terminal of the signal generator and the electronic transformer tester, and is used for filtering the initial analog signal generated by the signal generator to obtain an analog signal, and inputting the analog signal from the analog signal terminal to the electronic transformer tester; a sine wave sampling value message generator is connected to the data message terminal of the electronic transformer tester, and is used for generating a standard data message according to the analog initial phase value of the analog signal, and inputting the standard data message from the data message terminal to the electronic transformer tester, so that the electronic transformer tester processes the analog signal and the standard data message to obtain a phase error measured value, and compares the phase error measured value with a preset phase error standard value to determine the detection error value of the electronic transformer tester. The detection system of the electronic transformer calibrator transforms the traceability of digital quantity into analog quantity traceability through the digital waveform replacement method, thereby realizing the phase synchronization of digital quantity and analog quantity; at the same time, the initial phase value of the fundamental wave is accurately calibrated through the signal generator and the low-pass filter, and the error is eliminated by compensating the initial phase of the sine wave sampling value message generator; and the initial phase of the waveform compensation of the low-pass filter and the sine wave sampling value message generator is combined to eliminate the phase shift of the low-pass filter; not only can it ensure that the waveform becomes a continuous phase, but also will not introduce excessive phase error due to the resistance and capacitance error of the low-pass filter, thereby improving the accuracy of the angle difference traceability of the electronic transformer calibrator. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 It is a structural schematic diagram of a detection system of an electronic transformer tester provided in one embodiment of the present application;

[0050] Figure 2 is a structural schematic diagram of a signal generator provided by an embodiment of the present application;

[0051] Figure 3 It is a schematic diagram of step wave data and synchronization pulse signal PPS output by a signal generator provided by an embodiment of the present application;

[0052] Figure 4 is a structural schematic diagram of a low-pass filter provided by an embodiment of the present application;

[0053] Figure 5 It is a flow chart of a detection method of an electronic transformer tester provided in one embodiment of the present application;

[0054] Figure 6 It is a flow chart of a detection method of an electronic transformer tester provided in another embodiment of the present application;

[0055] Figure 7 It is a structural diagram of a terminal device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0056] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0057] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0058] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0059] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0060] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0061] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0062] See also Figure 1 , Figure 1 1 is a schematic diagram of a detection system of an electronic transformer tester provided in an embodiment of the present application. The detection system 100 of the electronic transformer tester includes:

[0063] Signal generator 10, low pass filter 20, sine wave sampling value message generator 30, wherein:

[0064] The signal generator 10 is used to store a plurality of preset waveform data, and to perform digital-to-analog conversion on the stored preset waveform data having a preset frequency and a preset number of sampling points, so as to generate an initial analog signal for detecting the electronic transformer tester 40;

[0065] The signal generator 10 includes a synchronization pulse output module 11, which is used to output a synchronization pulse signal through the synchronization pulse output module 11 at the starting position of the first rising edge of the first waveform period of the preset waveform data; and output the synchronization pulse signal to the synchronization pulse receiving module 41 in the electronic transformer tester 40, so that the signal generator 10 is synchronized with the clock of the electronic transformer tester 40;

[0066] The low-pass filter 20 is connected to the analog signal terminal of the signal generator 10 and the electronic transformer tester 40, respectively, and is used to filter the initial analog signal generated by the signal generator 10 to obtain an analog signal, and input the analog signal from the analog signal terminal to the electronic transformer tester 40;

[0067] The sine wave sampling value message generator 30 is connected to the data message terminal of the electronic transformer tester 40, and is used to generate a standard data message according to the analog initial phase value of the analog signal, and input the standard data message from the data message terminal to the electronic transformer tester 40, so that the electronic transformer tester 40 processes the analog signal and the standard data message to obtain the actual measured value of the phase error, and compares the actual measured value of the phase error with the preset phase error standard value to determine the detection error value of the electronic transformer tester 40.

[0068] It should be noted that the detection system 100 of the electronic transformer tester is a system for verifying the angular error accuracy of the electronic transformer tester. The detection system 100 of the electronic transformer tester includes a signal generator 10, a low-pass filter 20 and a sine wave sampling value message generator 30.

[0069] Specifically, the signal generator 10 is an electrical signal device that can generate a specific waveform. In the detection system 100 of the electronic transformer tester, the signal generator 10 stores a variety of preset waveform data, and can perform digital-to-analog conversion on the preset waveform data, thereby obtaining an initial analog signal for detecting the electronic transformer tester. Among them, the preset waveform data is specific waveform data stored in the signal generator 10. These waveform data include a preset frequency and a preset number of sampling points. The preset frequency is a preset waveform frequency, and the preset number of sampling points is a preset number of sampling points of the waveform. Digital-to-analog conversion is the process of converting a digital signal into an analog signal, that is, the stored preset waveform data is a digital signal, and the initial analog signal obtained after performing digital-to-analog conversion is an analog signal. As Figure 1 In FIG. 1 , a and x represent output terminals of the initial analog signal in the signal generator 10 .

[0070] The low-pass filter 20 is a filter that allows low-frequency signals to pass through but blocks high-frequency signals from passing through. In the detection system 100 of the electronic transformer tester, the low-pass filter 20 is connected to the signal generator 10 to filter the high-frequency components of the initial analog signal generated by the signal generator 10 to obtain a continuous analog signal; the low-pass filter 20 is also connected to the analog signal terminal of the electronic transformer tester 40 to input the obtained analog signal from the analog signal terminal into the electronic transformer tester 40. Among them, the analog signal terminal is a port on the electronic transformer tester 40 for receiving analog signals. The data message terminal is a port on the electronic transformer tester 40 for receiving standard data messages. As Figure 1 In the figure, a1 and x1 represent analog signal terminals in the electronic transformer tester 40, and the data message terminal is connected to the sine wave sampling value message generator 30 via Ethernet, and the message protocol transmitted is the IEC61850-9-2 standard.

[0071] The sine wave sampling value message generator 30 is a device for generating a data message containing a standard sine wave. In the detection system 100 of the electronic transformer tester, the sine wave sampling value message generator 30 is a set of software running on a terminal device such as a computer, which can generate a standard sine wave, and its initial phase and frequency can be digitally defined. In this embodiment, the sine wave sampling value message generator 30 used is connected to the data message end of the electronic transformer tester 40 via Ethernet, and the digital amount of the sine wave that can be generated has at least 1 million quantizations, and the error does not exceed 1ppm. Among them, the standard data message meets the IEC61850-9-2 standard format of the electronic transformer transmission message protocol. The simulated initial phase value refers to the initial phase of the analog signal, and the initial phase value of the standard data message can be determined according to the simulated initial phase value. The initial phase is the phase offset of the waveform relative to a reference point at the starting time. Among them, the simulated initial phase value is determined according to the first phase value of the initial analog signal and the second phase lag value generated after the initial analog signal is processed by a low-pass filter.

[0072] It should be understood that the initial phase of the initial analog signal, i.e., the first phase value, can be accurately calibrated through the massive preset waveform data and the low-pass filter 20 in the signal generator; by combining the low-pass filter 20 and the sine wave sampling value message generator 30 to compensate for the initial phase of the waveform, the phase shift of the low-pass filter can be eliminated, thereby converting the phase of the preset waveform data into a continuous phase without introducing excessive phase errors due to resistance-capacitance errors in the low-pass filter.

[0073] The synchronization pulse output module 11 is a timer module in the signal generator 10, which is used to output a synchronization pulse signal at the starting position of the first rising edge of the first waveform period of the preset waveform data. The synchronization pulse signal is used to synchronize the clock of the signal generator 10 with the electronic transformer tester 40. The synchronization pulse receiving module 41 is a module in the electronic transformer tester 40, which is used to receive the synchronization pulse signal output by the synchronization pulse output module 11 in the signal generator 10 and synchronize with the clock of the signal generator.

[0074] Among them, the waveform cycle refers to the time that a complete waveform takes from the starting point to the end point, and a waveform cycle usually includes the rising edge, top stable state, falling edge and bottom stable state of the waveform. The rising edge refers to the transition process of the signal from a low level to a high level, indicating a new data bit or the moment when an operation begins. In this embodiment, the first waveform cycle is the first complete waveform cycle in the preset waveform data, that is, the reference cycle at which the signal generator 10 starts to output the signal and is used for synchronization. The first rising edge is the moment when the signal changes from a low level to a high level for the first time in the first waveform cycle. The first rising edge is used as a trigger point for outputting a synchronization pulse signal to ensure that the clocks of the signal generator 10 and the electronic transformer tester 40 can be synchronized.

[0075] It should be understood that, through the synchronization pulse signal, the signal generator 10 and the electronic transformer tester 40 can jointly determine an accurate time starting point, and at the same time ensure that the initial analog signal generated by the signal generator 10 and the analog signal received by the electronic transformer tester 40 are aligned in time. That is, clock synchronization can provide a unified time reference, so that the time error between the initial analog signal generated by the signal generator 10 and the analog signal received by the electronic transformer tester 40 is minimized, thereby improving the accuracy and reliability of the verification.

[0076] After the electronic transformer tester 40 receives the analog signal and the standard data message, the electronic transformer tester 40 processes the analog signal and the standard data message to obtain the actual measured value of the phase error. The actual measured value of the phase error is the value processed by the electronic transformer tester 40. The actual measured value of the phase error is compared with the preset phase error standard value to obtain the detection error value of the electronic transformer tester 40. Among them, the preset phase error standard value is a pre-set standard value, which is used to evaluate the detection performance of the electronic transformer tester. The detection error value is an error value obtained by comparing the actual measured value of the phase error with the preset phase error standard value, which is used to determine the detection error of the electronic transformer tester.

[0077] It can be understood that the present embodiment provides a detection system for an electronic transformer tester, the detection system comprising: a signal generator, a low-pass filter, and a sine wave sampling value message generator, wherein the signal generator is used to store a plurality of preset waveform data, and to perform digital-to-analog conversion on the stored preset waveform data having a preset frequency and a preset number of sampling points, so as to generate an initial analog signal for detecting the electronic transformer tester; the signal generator comprises a synchronization pulse output module, which is used to output a synchronization pulse signal through the synchronization pulse output module at the starting position of the first rising edge of the first waveform period of the preset waveform data; and, output the synchronization pulse signal to the synchronization pulse receiving module in the electronic transformer tester, so as to synchronize the signal generator with the electronic transformer tester. Clock synchronization; a low-pass filter, connected to the analog signal end of the signal generator and the electronic transformer calibrator respectively, for filtering the initial analog signal generated by the signal generator to obtain an analog signal, and inputting the analog signal from the analog signal end to the electronic transformer calibrator; a sine wave sampling value message generator, connected to the data message end of the electronic transformer calibrator, for generating a standard data message according to the analog initial phase value of the analog signal, and inputting the standard data message from the data message end to the electronic transformer calibrator, so that the electronic transformer calibrator processes the analog signal and the standard data message to obtain a measured value of the phase error, and compares the measured value of the phase error with a preset standard value of the phase error to determine the detection error value of the electronic transformer calibrator. The detection system of the electronic transformer calibrator transforms the traceability of digital quantity into analog quantity traceability through the digital waveform replacement method, thereby realizing the phase synchronization of digital quantity and analog quantity; at the same time, the initial phase value of the fundamental wave is accurately calibrated through the signal generator and the low-pass filter, and the error is eliminated by compensating the initial phase of the sine wave sampling value message generator; and the initial phase of the waveform compensation of the low-pass filter and the sine wave sampling value message generator is combined to eliminate the phase shift of the low-pass filter; not only can it ensure that the waveform becomes a continuous phase, but also will not introduce excessive phase error due to the resistance and capacitance error of the low-pass filter, thereby improving the accuracy of the angle difference traceability of the electronic transformer calibrator.

[0078] In a possible implementation, the signal generator 10 includes a waveform memory 12, a digital signal processor 13 and a digital-to-analog converter 14; wherein,

[0079] The waveform memory 12 is used to store a plurality of preset waveform data; wherein the preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data;

[0080] The digital signal processor 13 is connected to the waveform memory 12 and the digital-to-analog converter 14, respectively, and is used to read the preset square wave data with a preset frequency and a preset number of sampling points in the waveform memory 12, and overlap the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data to determine the starting position of the preset square wave data;

[0081] The digital signal processor 13 is further configured to read the preset step wave data having a preset frequency and a preset number of sampling points from the waveform memory 12 after determining the starting position of the preset square wave data, so as to replace the preset square wave data with the preset step wave data, and send the preset step wave data to the digital-to-analog converter 14 at a preset sending rate;

[0082] The digital-to-analog converter 14 is connected to the low-pass filter 20 and is used to perform digital-to-analog conversion on the preset step wave data sent by the digital signal processor to obtain an initial analog signal.

[0083] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a structure of a signal generator provided by an embodiment of the present application. Figure 2 As shown in , the signal generator 10 is composed of a waveform memory 12, a digital signal processor 13 and a digital-to-analog converter 14, and a and x represent the output ends of the initial analog signal in the signal generator 10. Among them, the waveform memory 12 is a synchronous dynamic random access memory using 8 megabytes, which stores a plurality of preset waveform data, including a plurality of preset square wave data and a plurality of preset step wave data. The preset square wave data and the preset step wave data are two types of data with different waveforms. Among them, the preset square wave data is a waveform signal with a specific frequency and duty cycle, and its waveform changes periodically between a high level and a low level. The preset step wave data is a non-periodic waveform signal, and its waveform suddenly jumps from one level to another at a certain moment, remains unchanged for a period of time, and then may jump again, and this jump can be repeated to form multiple steps.

[0084] The digital signal processor 13 is a microprocessor for processing digital signals. In the signal generator 10, the digital signal processor 13 is used to read the preset square wave data with a preset frequency and a preset number of sampling points in the waveform memory 12, overlap the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data, thereby obtaining the starting position of the preset square wave data, and, after determining the starting position of the preset square wave data, read the preset step wave data with a preset frequency and a preset number of sampling points in the waveform memory 12, thereby replacing the preset square wave data with the preset step wave data, and sending the preset step wave data to the digital-to-analog converter 14 at a preset sending rate. Among them, the pulse rising edge refers to the moment when the synchronization pulse signal changes from a low level to a high level. The preset sending rate is the preset rate at which the digital signal processor 13 sends data to the digital-to-analog converter 14, which determines the frequency and sampling points of the generated analog signal.

[0085] The digital-to-analog converter 14 is a module for converting a digital signal into an analog signal. In the detection system 100 of the electronic transformer tester, the digital-to-analog converter 14 is used to convert the preset step wave data of the digital quantity sent by the digital signal processor 13 into an initial analog signal of the analog quantity. Then, the digital-to-analog converter 14 is connected to the low-pass filter 20 to output the initial analog signal to the low-pass filter 20.

[0086] Specifically, in this embodiment, the digital signal processor 13 uses the BF609 chip and peripherals, and the chip has a large number of built-in peripherals, such as timers (synchronous pulse output modules), general input / output ports, storage interfaces, etc. The digital-to-analog converter 14 uses the EVAL-AD5791SDZ-UG-development board, which integrates a 20BIT AD5791 digital-to-analog converter and a reference voltage. Since the maximum clock of AD5791SDZ is 40ns, 25 clocks are required to output a sampling point, that is, the fastest 1us sends a digital-to-analog conversion data in the digital signal processor 13, so the maximum number of steps fitted at a frequency of 50Hz is 20,000 points per waveform cycle. Therefore, the preset waveform data of 20,000 sampling points are stored in the waveform memory 12, including preset square wave data and preset step wave data. Specifically, the preset waveform data with a preset frequency of 50 Hz and a preset number of sampling points of 20,000 is first extracted from the waveform memory 12, and the waveform is continuously sent through the digital signal processor 13 at a preset sending rate of sending one digital-to-analog conversion data of 1 us, and the synchronization pulse signal PPS (once per second) of the timer is set at the starting position of the first rising edge of the first waveform cycle of 50 waveform cycles. At this time, the pulse width of the timer is set to 100 us, and the pulse period is 1s.

[0087] like Figure 3 As shown, Figure 3 FIG. 1 is a schematic diagram of a step wave data and a synchronous pulse signal PPS output by a signal generator provided by an embodiment of the present application. Figure 3 As shown, Figure 3 The step wave in the output is 100 steps, while the step wave output in the actual detection process is 20,000 steps. Figure 3 The 100 steps are used only to express that the timer PPS output moment corresponds to the starting position of the first step of the first waveform cycle.

[0088] The sinusoidal signal of the step wave is expressed by formula (1).

[0089] (1)

[0090] In formula (1), represents a sinusoidal signal of a step wave, , N is the number of sampling points in a waveform period. In this embodiment, N=20000.

[0091] The ideal step wave signal Fourier series can be expressed by formula (2).

[0092] (2)

[0093] In formula (2), represents a sinusoidal signal of a step wave, , represents the coefficients of the Fourier series, k=1,2,..., , N represents the number of sampling points in one waveform period.

[0094] from Figure 3 From formula (2), it can be seen that the step wave contains a lot of high-order harmonics.

[0095] Moreover, the initial phase value of the step wave is shown in formula (3).

[0096] (3)

[0097] It can be seen from formula (2) that the initial phase value is directly superimposed on the initial phase of the sine wave sampling value message generator 30, and the harmonic order is {kN+1, kN-1}, where k=1,2, ..., although the harmonic content is very small, only 1 / (kN±1), when N=20000, the maximum harmonic frequency is and Hz. At this time, although the harmonic content is very small, the frequency is 1MHz±50Hz, because the design target requirement is 25ppm, it needs to be aligned and filtered, otherwise, the step wave signal will have a phase discontinuity of ±0.55 points at 50Hz, causing phase tracing errors. Therefore, it needs to be filtered through a low-pass filter.

[0098] In a possible implementation, the analog initial phase value of the analog signal is the sum of a first phase value of the initial analog signal and a second phase lag value generated after the initial analog signal is processed by a low-pass filter.

[0099] It should be noted that the first phase value is the initial phase of the fundamental wave in the initial analog signal. Since the initial analog signal is filtered by a low-pass filter, the phase will have a certain delay, that is, the second phase lag value. Therefore, the simulated initial phase value of the analog signal is the sum of the first phase value and the second phase lag value.

[0100] Further, the first phase value of the initial analog signal is determined according to a preset number of sampling points and a preset fundamental wave phase calculation formula; wherein the preset fundamental wave phase calculation formula is:

[0101] ;

[0102] in, represents the first phase value, and N represents the preset number of sampling points.

[0103] Following the above example, in this embodiment, the preset number of sampling points N of the extracted preset step wave is 20000, and then it is calculated according to the preset fundamental wave phase calculation formula, that is, , get the first phase value It is -0.54 points.

[0104] In a possible implementation, the low-pass filter 20 includes a first-stage low-pass filter and a first operational amplifier A1; wherein,

[0105] A first-stage low-pass filter, comprising a first resistor R1 and a first capacitor C1, for filtering high-frequency components in the initial analog signal to obtain a filtered analog signal;

[0106] The first operational amplifier A1 is used to amplify the filtered analog signal to obtain an analog signal.

[0107] like Figure 4 As shown, Figure 4 1 is a schematic diagram of a low-pass filter structure provided by an embodiment of the present application. Figure 4As shown in , the low-pass filter 20 includes a first-stage low-pass filter and a first operational amplifier A1. The first-stage low-pass filter is an RC filter composed of a first resistor R1 and a first capacitor C1, which is used to filter the high-frequency components in the initial analog signal to obtain a filtered analog signal; the first operational amplifier A1 is used to amplify the filtered analog signal to obtain an analog signal. Figure 4 In the figure, OUT indicates the output terminal.

[0108] Furthermore, the second phase lag value is determined according to the first resistor R1, the first capacitor C1 and a preset phase shift calculation formula; wherein the preset phase shift calculation formula is shown in formula (4).

[0109] (4)

[0110] In formula (4), represents the second phase lag value, f represents the preset frequency, represents the resistance value of the first resistor R1, represents the capacitance value of the first capacitor C1.

[0111] Following the above example, in this embodiment, the low-pass filter 20 is used to filter out Figure 3 Specifically, in order to ensure the continuity of the phase of the fundamental wave in the initial analog signal, the resistance value of the first resistor R1 is The capacitance value of the first capacitor C1 is 100Ω, the accuracy is 0.01%, and the capacitance value of the first capacitor C1 is The first operational amplifier A1 uses an operational amplifier chip ADA4522, which adopts a zero-drift design and extremely low offset voltage drift, which can avoid the influence of subsequent loads on the phase shift of the first-stage low-pass filter (RC filter).

[0112] Following the above example, in this embodiment, the preset sampling point number N of the preset step wave is 20000, that is, the number of steps is 20000, and the frequency of the smallest harmonic is about 1MHz. Therefore, the cutoff frequency of the first-stage low-pass filter is , the high frequency part of the 1MHz step wave can be filtered out.

[0113] Bundle , , f=50Hz is substituted into the preset phase shift calculation formula, that is, formula (4), the phase shift of the first-order low-pass filter is calculated, and the second phase lag value is obtained, that is,

[0114] .

[0115] Therefore, the initial analog signal has a phase lag of -1.08 minutes after passing through the low-pass filter 20, that is, the second phase lag value is -1.08 minutes. Then the analog initial phase value of the analog signal is -(0.54+1.08) minutes. The delayed phase (second phase lag value) of the low-pass filter is directly superimposed on the initial phase of the sine wave sampling value message generator 30.

[0116] In a possible implementation, the accuracy level of the low-pass filter 20 is 0.3ppm-0.4ppm, the accuracy level of the sine wave sampling value message generator 30 is 0.9ppm-1ppm, and the accuracy level of the signal generator 10 is 9ppm-10ppm.

[0117] Specifically, the accuracy level of the low-pass filter 20 is 0.3ppm-0.4ppm. Preferably, since the accuracy of the first-stage low-pass filter can reach 0.1%, the maximum phase error of the low-pass filter is The accuracy level is 0.3ppm. The accuracy level of the sine wave sampling value message generator 30 is 0.9ppm-1ppm. The error between the synchronization pulse signal PPS and the preset square wave signal is about 0.03 points, which is converted to an accuracy level of about 10ppm. Therefore, the accuracy level of the signal generator 10 is 9ppm-10ppm. Therefore, in this embodiment, the angular difference value transmission accuracy of the electronic transformer tester can be better than 25ppm.

[0118] In a possible implementation, the electronic transformer tester 40 processes the analog signal and the standard data message to obtain a measured value of the phase error, including:

[0119] The analog signal terminal of the electronic transformer tester 40 receives the analog signal, and the data message terminal of the electronic transformer tester 40 receives the standard data message;

[0120] Performing analog-to-digital conversion on the analog signal and extracting the initial phase of the analog signal to obtain a measured initial phase value of the analog signal;

[0121] The measured initial phase value of the analog signal is calculated to differ from the standard initial phase value of the standard data message to obtain a measured value of the phase error; wherein the standard initial phase value of the standard data message is determined by the simulated initial phase value of the analog signal.

[0122] Specifically, first, the analog signal end of the electronic transformer tester 40 receives the analog signal sent by the low-pass filter 20, and the data message end of the electronic transformer tester 40 receives the standard data message sent by the sine wave sampling value message generator 30; then, the analog signal is converted from an analog quantity to a digital quantity, and the analog signal of the digital quantity is processed to extract its initial phase, thereby obtaining the measured initial phase value of the analog signal. Among them, the measured initial phase value is extracted after the electronic transformer tester 40 performs analog-to-digital conversion, and is a measured value. Then, the measured initial phase value of the analog signal is calculated with the standard initial phase value of the standard data message to obtain the measured value of the phase error. Among them, the standard initial phase value is obtained based on the simulated initial phase value of the analog signal, and the simulated initial phase value is a theoretical value obtained by calculation. Therefore, according to the comparison between the measured value of the phase error and the preset standard value of the phase error, the detection error value of the electronic transformer tester 40 can be obtained, and the detection performance of the electronic transformer tester can be evaluated.

[0123] It should be understood that the information interaction, execution process and other contents between the modules in the above embodiments are determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0124] Corresponding to the detection system of an electronic transformer tester in the above embodiment, Figure 5 A flow chart of a detection method of an electronic transformer tester provided by an embodiment of the present application is shown. For ease of explanation, only the part related to the embodiment of the present application is shown. The detection method of the electronic transformer tester adopts the detection system of any of the above-mentioned electronic transformer testers for detection, including:

[0125] S11, performing digital-to-analog conversion on the preset waveform data having a preset frequency and a preset number of sampling points stored therein by a signal generator to generate an initial analog signal for detecting the electronic transformer tester;

[0126] S12, at the starting position of the first rising edge of the first waveform period of the preset waveform data, outputting a synchronization pulse signal through a synchronization pulse output module in the signal generator, and outputting the synchronization pulse signal to a synchronization pulse receiving module in the electronic transformer tester, so as to synchronize the clocks of the signal generator and the electronic transformer tester;

[0127] S13, filtering the initial analog signal generated by the signal generator through a low-pass filter to obtain an analog signal, and inputting the analog signal from the analog signal terminal to the electronic transformer tester;

[0128] S14, generating a standard data message according to the simulated initial phase value of the analog signal through a sine wave sampling value message generator, and inputting the standard data message from a data message terminal to an electronic transformer tester;

[0129] S15, processing the analog signal and the standard data message by an electronic transformer tester to obtain a measured value of the phase error;

[0130] S16. Compare the actual measured value of the phase error with the preset standard value of the phase error to determine the detection error value of the electronic transformer tester.

[0131] It should be noted that the detection method of the electronic transformer tester mainly adopts the detection system of any of the above-mentioned electronic transformer testers for detection.

[0132] In step S11, the signal generator selects preset waveform data with a preset frequency and a preset number of sampling points from the waveform data stored therein, wherein the preset waveform data includes preset square wave data and preset step wave data. Then, the extracted preset waveform data is converted from digital to analog to generate an initial analog signal for detecting the electronic transformer tester.

[0133] In step S12, at the starting position of the first rising edge of the first waveform period of the preset waveform data, the synchronization pulse output module in the signal generator outputs a synchronization pulse signal. This synchronization pulse signal will be sent to the synchronization pulse receiving simulation in the electronic transformer tester, thereby ensuring the clock synchronization of the signal generator and the electronic transformer tester. By ensuring that the signal generator and the electronic transformer tester have the same time reference when processing signals, the accuracy of detection is improved.

[0134] In step S13, the initial analog signal generated by the signal generator is filtered by a low-pass filter to remove high-frequency components, so that the phase of the initial analog signal becomes a continuous phase. The analog signal obtained after the processing is input to the analog signal terminal of the electronic transformer tester as the input test signal of the electronic transformer tester.

[0135] In step S14, a sine wave sampling value message generator generates a standard data message according to the simulated initial phase value of the analog signal, and the standard data message contains waveform sampling value information corresponding to the analog signal. The standard data message is input to the data message terminal of the electronic transformer tester as the input standard signal of the electronic transformer tester.

[0136] In step S15, the analog signal and the standard data message are processed by the electronic transformer tester to obtain the measured value of the phase error. Specifically, the analog signal end of the electronic transformer tester receives the analog signal, and the data message end of the electronic transformer tester receives the standard data message; the analog signal is converted into a digital form and the initial phase of the analog signal is extracted to obtain the measured initial phase value of the analog signal; the measured initial phase value of the analog signal is calculated to be different from the standard initial phase value of the standard data message to obtain the measured value of the phase error; wherein the standard initial phase value of the standard data message is determined by the simulated initial phase value of the analog signal.

[0137] In step S16, the phase error measured value is compared with the preset phase error standard value. If the phase error measured value is within the range allowed by the preset phase error standard value, the detection performance of the electronic transformer tester is considered qualified. By comparing the measured value with the standard value, the detection performance of the electronic transformer tester can be evaluated and calibrated.

[0138] It can be understood that the detection method of the electronic transformer calibrator transforms the traceability of digital quantity into analog quantity traceability through the digital waveform replacement method, thereby realizing the phase synchronization of digital quantity and analog quantity; at the same time, the initial phase value of the fundamental wave is accurately calibrated through the signal generator and the low-pass filter, and the error is eliminated by compensating the initial phase number of the sinusoidal wave sampling value message generator; and, the initial phase of the waveform compensation of the low-pass filter and the sinusoidal wave sampling value message generator is combined to eliminate the phase shift of the low-pass filter; it can not only ensure that the waveform becomes a continuous phase, but also will not introduce excessive phase error due to the resistance and capacitance error of the low-pass filter, thereby improving the accuracy of the angle difference traceability of the electronic transformer calibrator.

[0139] In a possible implementation, the preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data;

[0140] The preset waveform data with preset frequency and preset sampling points stored therein is converted into digital-to-analog format by a signal generator to generate an initial analog signal for detecting the electronic transformer tester, including:

[0141] Reading preset square wave data having a preset frequency and a preset number of sampling points stored in a waveform memory in a signal generator, and overlapping the starting position of a pulse rising edge of a synchronization pulse signal with the starting position of a first rising edge of a first waveform period in the preset square wave data to determine a starting position of the preset square wave data;

[0142] After determining the starting position of the preset square wave data, reading the preset step wave data having the preset frequency and the preset number of sampling points stored in the waveform memory to replace the preset square wave data with the preset step wave data, and sending the preset step wave data to the digital-to-analog converter in the signal generator at a preset sending rate;

[0143] The preset step wave data is converted into digital-to-analog form by a digital-to-analog converter to obtain an initial analog signal.

[0144] Specifically, first, the digital signal processor in the signal generator reads the preset square wave data with a preset frequency and a preset number of sampling points in the waveform memory, overlaps the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data, thereby obtaining the starting position of the preset square wave data; then, after determining the starting position of the preset square wave data, read the preset step wave data with a preset frequency and a preset number of sampling points in the waveform memory, thereby replacing the preset square wave data with the preset step wave data, and sending the preset step wave data to the digital-to-analog converter at a preset sending rate. Among them, the pulse rising edge refers to the moment when the synchronization pulse signal changes from a low level to a high level. The preset sending rate is the preset rate at which the digital signal processor sends data to the digital-to-analog converter, which determines the frequency and sampling points of the generated analog signal. Finally, the digital-to-analog converter converts the preset step wave data of the digital quantity sent by the digital signal processor into the initial analog signal of the analog quantity. It should be understood that this embodiment ensures the accurate synchronization and waveform replacement of the waveform data, and ensures the accuracy of the detection process.

[0145] It should be noted that since analog-to-digital converters have various delays, such as the analog front-end operational amplifier, anti-aliasing filter, ADC (analog-to-digital conversion) sampling and holding circuit delays, this will cause the phase between the primary analog quantity and the secondary digital quantity, which cannot be directly measured or directly transmitted. Based on the existing national standards, the core of the embodiment of this application is to establish an analog-to-digital synchronous traceability system through the waveform replacement method of the analog sine wave (actually the step wave after RC filtering) and PPS (second pulse). The core lies in the theoretical derivation of the initial phase of the waveform replacement method and the step wave and the continuous signal formed after filtering. The method of replacing the sine wave with a square wave uses an oscilloscope to calibrate the initial position of the 20,000-point step wave, and the timer can arbitrarily adjust the position of the PPS and the first step wave at a resolution of 10ns.

[0146] After the initial position of the 20,000-point step wave is determined by the square wave, the sampling points of the square wave are replaced by the sine wave. In this way, the purpose of accurately calibrating the initial moment of the first step of the step wave is achieved through the oscilloscope, thereby establishing the accurate phase relationship between the analog and digital, and providing the most basic analog-to-digital traceability platform for electronic voltage transformers or electronic current transformers.

[0147] In the specific application process, this embodiment realizes the conversion of the voltage value of 7.07V into the sampling value of 10kV IEC61850-9-2 or the sampling value of 1000A. Since the number 1 of IEC61850-9-2 represents 10mV and the value 1 represents 1mA, the quantization of the standard data message of 10kV and 1000A is 1ppm. When the electronic transformer tester is other rated values ​​of voltage or current, such as 100V or 1A, it can be realized by precise voltage conversion or current conversion. The traditional voltage conversion and current conversion can be directly traced, and the national standard can reach the accuracy of ppm.

[0148] Specifically, Figure 6 As shown, Figure 6 FIG. 1 is a flow chart of a detection method of an electronic transformer tester provided in another embodiment of the present application. Figure 6 In step S21, the waveform memory in the signal generator is set to a square wave signal with a sampling point number of 20,000 and a frequency of 50 Hz; then, the synchronous pulse signal PPS of the synchronous pulse output module (timer) in the control signal generator overlaps with the starting position of the rising edge of the square wave signal. In step S21, the PPS code delay of the timer is delayed by code before enabling the timer. The code is implemented using the zero time cycle empty instruction of the digital signal processor, and the empty instruction is ams ("nop;").

[0149] like Figure 6 In step S22, the waveform memory is set to a step wave signal with an initial phase of -(0.54+1.08) minutes and a sampling point number of 20,000. From the above formulas (3) and (5), it can be seen that the theoretical value of the initial phase of the step wave signal with 20,000 sampling points is -(0.54+1.08) minutes, that is, the simulated initial phase value is -(0.54+1.08) minutes.

[0150] like Figure 6 In step S23, the sine wave sampling value message generator outputs a standard data message with a standard initial phase of 10kV of 4KHz or 12.8kHz and a standard data message of -(0.54+1.08) minutes; when the electronic transformer tester is a voltage input, the preset phase error standard value is 0 minutes, then the phase error measured value minus the preset phase error standard value is the detection error value of the electronic transformer tester.

[0151] In step S24, the sine wave sampling value message generator can also output standard data messages with an initial phase of -(0.54+1.08)+100 minutes and -(0.54+1.08)-100 minutes of 10 kV at 4 kHz or 12.8 kHz respectively; when the electronic transformer tester is a voltage input, the preset phase error standard values ​​are 100 minutes and -100 minutes respectively, and the actual phase error value minus the preset phase error standard value is the detection error value of the electronic transformer tester.

[0152] Furthermore, when it is necessary to check other voltage values ​​or current values, the analog conversion method can be used to expand the method. The present embodiment establishes a phase standard between analog and digital. The accuracy level of the sine wave sampling value message generator of the standard value is 0.9ppm-1ppm, the accuracy level of the low-pass filter is 0.3ppm-0.4ppm, and the accuracy level of the signal generator is 9ppm-10ppm. Therefore, the accuracy of the present embodiment is mainly determined by the zero-crossing accuracy of the timer PPS and the square wave signal, and the angle difference value transmission accuracy of the electronic transformer tester can be better than 25ppm.

[0153] It should be noted that the detection method of the electronic transformer calibrator provided in the embodiment of the present application has the following advantages compared with the existing detection methods: (1) Good traceability. The phase traceability of digital and analog quantities is transformed into analog time traceability through the digital waveform replacement method, and the phase synchronization of digital and analog quantities is achieved through the oscilloscope measurement method, and the phase reference of digital and analog quantities is established. (2) High accuracy. The accuracy of the detection method of the sub-type transformer calibrator provided in this embodiment can reach 25ppm, with a typical value of 10ppm, which is better than the existing 0.01% electronic transformer calibrator calibration device and 30ppm PMU calibration device. (3) Low cost. The detection method of the sub-type transformer calibrator provided in this embodiment does not require expensive quantum equipment or high-precision instruments and meters, thereby reducing the detection cost.

[0154] It should be understood that the size of the sequence number of each step in the above embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. Since the detection method of the above electronic transformer tester is based on the same concept as the embodiment of the system of the present application, its specific functions and technical effects can be found in the system embodiment section, and will not be repeated here.

[0155] The present application also provides a terminal device, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of a terminal device provided in one embodiment of the present application. Figure 7The terminal device 5 of this embodiment includes: a memory 51, a processor 52, and a computer program stored in the memory 51 and executable on the processor 52. When the processor 52 executes the computer program, the steps in any one of the above-mentioned detection method embodiments of the electronic transformer tester are implemented.

[0156] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0157] An embodiment of the present application provides a computer program product. When the computer program product runs on a mobile terminal, the mobile terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0158] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiments can be implemented. Among them, 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 at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0159] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0160] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0161] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0162] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0163] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A detection system for an electronic transformer tester, characterized in that: The system comprises: a signal generator, a low-pass filter, and a sine wave sampling value message generator, wherein: The signal generator is used to store a plurality of preset waveform data, and to perform digital-to-analog conversion on the stored preset waveform data having a preset frequency and a preset number of sampling points, so as to generate an initial analog signal for detecting the electronic transformer tester; The signal generator comprises a synchronization pulse output module, which is used to output a synchronization pulse signal through the synchronization pulse output module at the starting position of the first rising edge of the first waveform period of the preset waveform data; and output the synchronization pulse signal to the synchronization pulse receiving module in the electronic transformer tester, so that the signal generator is synchronized with the clock of the electronic transformer tester; The low-pass filter is connected to the signal generator and the analog signal terminal of the electronic transformer tester, respectively, and is used to filter the initial analog signal generated by the signal generator to obtain an analog signal, and input the analog signal from the analog signal terminal to the electronic transformer tester; The sine wave sampling value message generator is connected to the data message terminal of the electronic transformer tester, and is used to generate a standard data message according to the simulated initial phase value of the analog signal, and input the standard data message from the data message terminal to the electronic transformer tester, so that the electronic transformer tester processes the analog signal and the standard data message to obtain a phase error measured value, and compares the phase error measured value with a preset phase error standard value to determine the detection error value of the electronic transformer tester; and, The signal generator includes a waveform memory, a digital signal processor and a digital-to-analog converter; wherein, The waveform memory is used to store a plurality of the preset waveform data; wherein the preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data; The digital signal processor is connected to the waveform memory and the digital-to-analog converter respectively, and is used to read the preset square wave data having the preset frequency and the preset number of sampling points in the waveform memory, and overlap the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data to determine the starting position of the preset square wave data; The digital signal processor is further configured to, after determining the starting position of the preset square wave data, read the preset step wave data having the preset frequency and the preset number of sampling points in the waveform memory, so as to replace the preset square wave data with the preset step wave data, and send the preset step wave data to the digital-to-analog converter at a preset sending rate; The digital-to-analog converter is connected to the low-pass filter and is used to perform digital-to-analog conversion on the preset step wave data sent by the data signal processor to obtain the initial analog signal.

2. The detection system of the electronic transformer tester according to claim 1, characterized in that: The analog initial phase value of the analog signal is the sum of the first phase value of the initial analog signal and the second phase lag value generated after the initial analog signal is processed by the low-pass filter.

3. The detection system of the electronic transformer tester according to claim 2, characterized in that: The first phase value of the initial analog signal is determined according to the preset number of sampling points and the preset fundamental phase calculation formula; wherein the preset fundamental phase calculation formula is: ； in, represents the first phase value, and N represents the preset number of sampling points.

4. The detection system of the electronic transformer tester according to claim 3, characterized in that: The low-pass filter comprises a first-stage low-pass filter and a first operational amplifier; wherein, The first-stage low-pass filter comprises a first resistor and a first capacitor, and is used to filter the high-frequency component in the initial analog signal to obtain a filtered analog signal; The first operational amplifier is used to perform signal amplification processing on the filtered analog signal to obtain the analog signal.

5. The detection system of the electronic transformer tester according to claim 4, characterized in that: The second phase lag value is determined according to the first resistor, the first capacitor and a preset phase shift calculation formula; wherein the preset phase shift calculation formula is: in, represents the second phase lag value, f represents the preset frequency, represents the resistance value of the first resistor, represents the capacitance value of the first capacitor.

6. The detection system of the electronic transformer tester according to claim 5, characterized in that: The accuracy level of the low-pass filter is 0.3ppm-0.4ppm, the accuracy level of the sine wave sampling value message generator is 0.9ppm-1ppm, and the accuracy level of the signal generator is 9ppm-10ppm.

7. The detection system of the electronic transformer tester according to claim 6, characterized in that: The electronic transformer tester processes the analog signal and the standard data message to obtain a phase error measured value, including: The analog signal terminal of the electronic transformer tester receives the analog signal, and the data message terminal of the electronic transformer tester receives the standard data message; Performing analog-to-digital conversion on the analog signal and extracting the initial phase of the analog signal to obtain a measured initial phase value of the analog signal; The measured initial phase value of the analog signal is calculated to differ from the standard initial phase value of the standard data message to obtain the actual measured value of the phase error; wherein the standard initial phase value of the standard data message is determined by the analog initial phase value of the analog signal.

8. A detection method for an electronic transformer tester, characterized in that: The detection is performed using the detection system of the electronic transformer tester according to any one of claims 1 to 7, comprising: The preset waveform data with a preset frequency and a preset number of sampling points stored therein is converted by a signal generator into digital-to-analog form to generate an initial analog signal for detecting the electronic transformer tester; At the starting position of the first rising edge of the first waveform period of the preset waveform data, a synchronization pulse signal is output through a synchronization pulse output module in the signal generator, and the synchronization pulse signal is output to a synchronization pulse receiving module in the electronic transformer tester, so that the signal generator is synchronized with the clock of the electronic transformer tester; Filtering the initial analog signal generated by the signal generator through a low-pass filter to obtain an analog signal, and inputting the analog signal from the analog signal terminal to the electronic transformer tester; Generate a standard data message according to the simulated initial phase value of the analog signal through a sine wave sampling value message generator, and input the standard data message from the data message terminal to the electronic transformer tester; The analog signal and the standard data message are processed by the electronic transformer tester to obtain a measured value of the phase error; Comparing the phase error measured value with a preset phase error standard value to determine the detection error value of the electronic transformer tester; and The preset waveform data includes a plurality of preset square wave data and a plurality of preset step wave data; The method of converting the stored preset waveform data with a preset frequency and a preset number of sampling points by a signal generator to generate an initial analog signal for detecting the electronic transformer tester includes: Reading the preset square wave data having the preset frequency and the preset number of sampling points stored in the waveform memory in the signal generator, and overlapping the starting position of the pulse rising edge of the synchronization pulse signal with the starting position of the first rising edge of the first waveform period in the preset square wave data to determine the starting position of the preset square wave data; After determining the starting position of the preset square wave data, reading the preset step wave data having the preset frequency and the preset number of sampling points stored in the waveform memory to replace the preset square wave data with the preset step wave data, and sending the preset step wave data to the digital-to-analog converter in the signal generator at a preset sending rate; The preset step wave data is converted into digital-to-analog format by the digital-to-analog converter to obtain the initial analog signal.

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