Sampling calibration device and method based on electronic transformer

Abstract

The invention provides a sampling calibration device and method based on an electronic transformer, and relates to the technical field of electronic transformer detection. An improvement scheme is provided for the anti-electromagnetic interference capability of small signal transmission of the electronic transformer, the signal acquisition and conditioning device modularly integrated with the conditioning unit is designed and arranged in the protection device, data acquisition of the electronic transformer is completed, and the anti-electromagnetic interference capability of small signal transmission of the electronic transformer is improved. Current or voltage acquired by the electronic transformer is conditioned into a range capable of being acquired by the AD sampling module, and the anti-electromagnetic interference capability of low-current signal transmission between the electronic transformer and the protection device is improved. According to the sampling calibration device based on the electronic mutual inductor, the integration level of a line protection device is improved, communication connecting lines in a cabinet are simplified, the number of communication optical fibers is reduced, independent acquisition equipment and merging units do not need to be additionally arranged, the manufacturing cost of intelligent equipment is reduced, and application and popularization are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of electronic mutual inductor detection, and in particular to a sampling and calibration device based on an electronic mutual inductor. Background Art

[0002] With the rapid promotion and development of smart grids and smart substations, electronic instrument transformers are increasingly widely used. As an important source of digital information for smart substations, the performance of electronic instrument transformers has received widespread attention and a large number of verifications. The main performance concerns of electronic instrument transformers include two categories: 1) The reliability of electronic instrument transformers, including the ability to withstand harsh environments such as weather environment, electromagnetic environment and operating environment in actual applications, as well as the stability of performance during long-term operation; 2) The accuracy of electronic instrument transformers, including the drift of instrument transformer accuracy caused by factors such as ambient temperature changes or aging of components. Therefore, electronic instrument transformers need to be tested before they are applied on site. The detection of electronic instrument transformers on site generally includes offline verification of accuracy or short-term verification with power on, as well as inspection or power-off inspection of key performance of electronic instrument transformers.

[0003] The commonly used electronic transformers mainly include primary sensing components, signal acquisition and conditioning devices and merging units. The primary sensing components include low-power coils for sensing current, Rogowski coils and capacitive voltage dividers for sensing voltage; the signal acquisition and conditioning device receives the analog small signal output by the primary sensor, converts it into a digital signal of current and voltage, and packages the data and sends it to the merging unit through optical fiber; the merging unit performs secondary conversion and digital output. The relay protection scheme based on electronic transformers currently used in engineering applications mainly goes through four parts: 1) electronic transformer acquisition unit, which mainly completes the acquisition of small signals of current or voltage electronic transformers; 2) merging unit, which mainly merges the FT3 signals of CT and PT acquisition units and outputs the IEC-61850-9-2SV message of the 61850 standard; 3) protection device, which mainly receives the merging unit SV data to calculate the sampled data for protection logic judgment; 4) acquisition verification, which completes the verification of the acquisition unit through the merging unit data. The prominent problem of this scheme is that there are many links in the data collection of electronic transformers to the protection device, which brings superposition errors and affects the accuracy of the sampling of the protection device. In other words, in the above protection scheme, there is a problem that the small current signal transmission link between the electronic transformer and the protection device has weak anti-electromagnetic interference ability. Moreover, in the above relay protection scheme based on electronic transformers, the installation size and verification method of the acquisition units of various manufacturers are different, which is not easy to promote and apply. In addition, there is currently little research on online monitoring and verification of electronic transformers, and some online verification functions use virtual instruments as the detection interface, which is only suitable for local observation and cannot be remotely monitored.

[0004] Based on this, the present invention is proposed. Summary of the invention

[0005] To solve at least one of the problems in the above-mentioned background technology, the object of the present invention is to provide a sampling and calibration device and method based on an electronic transformer, so as to improve the anti-electromagnetic interference capability of small current signal transmission between the electronic transformer and the protection device.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a sampling and calibration device based on an electronic transformer, a protection device based on an electronic transformer, a central processor built in the protection device, an ADC analog-to-digital conversion module, an AD sampling module and a process layer acquisition module are arranged on the central processor, the process layer acquisition module is used to perform process layer acquisition on the data sampled by AD and output SV data; the sampling and calibration device comprises: a signal acquisition and conditioning device, which is modularly integrated with a conditioning unit, is arranged in the protection device and is electrically connected to the central processor of the protection device, and is used to acquire and condition the current analog small signal and / or voltage analog small signal output by the calibrated electronic transformer for AD sampling; a test calibrator, which is used to obtain and verify the analog signal output by the standard electronic transformer source and the SV data output by the central processor of the protection device, and provide the signal amplitude deviation and phase difference between the calibrated electronic transformer and the standard electronic transformer source for calibration; a calibration device, which communicates with the AD sampling module and the test calibrator of the protection device respectively, calibrates the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator, and completes the online calibration of the data of the calibrated electronic transformer.

[0008] The present invention provides a preferred solution, wherein the signal acquisition and conditioning device is in the form of an acquisition board, and the acquisition board is integrated with: a measuring current conditioning unit, used for conditioning the measuring current signal on the current channel of the calibrated electronic transformer before AD sampling; a protection current conditioning unit, used for conditioning the protection current signal on the current channel of the calibrated electronic transformer before AD sampling; and a voltage conditioning unit, used for conditioning the measuring voltage signal and the protection voltage signal on the voltage channel of the calibrated electronic transformer before AD sampling.

[0009] Furthermore, the measuring current conditioning unit includes a front-end precision acquisition module, a first integration module, a first rear-end voltage regulation module, a first isolation module and a first rear-end precision acquisition module. The measuring current of the calibrated electronic transformer is sequentially conditioned by the above modules of the measuring current conditioning unit and then provided for AD sampling; the protection current conditioning unit includes a voltage regulation module, a second integration module, a front-end voltage regulation module, a second isolation module and a second rear-end precision acquisition module. The protection current of the calibrated electronic transformer is sequentially conditioned by the above modules of the protection current conditioning unit and then provided for AD sampling; the voltage conditioning unit includes a following module, a second rear-end voltage regulation module, a third isolation module and a third rear-end precision acquisition module. The measuring voltage and protection voltage of the calibrated electronic transformer are sequentially conditioned by the above modules of the voltage conditioning unit and then provided for AD sampling.

[0010] In order to achieve precise acquisition of the current analog quantity of the current channel and overcurrent protection, the present invention provides a preferred solution, wherein the front-end precision acquisition module includes a TVS tube, a voltage-stabilizing diode, a resistor, a capacitor and an instrument amplifier. Overcurrent and overvoltage protection are performed by the TVS tube and the voltage-stabilizing diode, and the current analog quantity is more accurately acquired and measured by the resistor, the capacitor and the instrument amplifier.

[0011] In order to further realize more precise analog signal acquisition of the current channel, the present invention provides a preferred solution, wherein the first integration module and the second integration module both include resistors, capacitors and operational amplifiers for restoring the analog quantities of the measured current and protection current after differential operation.

[0012] In order to further realize more precise signal acquisition of current and voltage channels and reduce the impact of the protection current channel on the subsequent modules due to the input of a large overload voltage, the present invention provides a preferred solution, wherein the front-end voltage regulating module is used to reduce the overload voltage of the protection current channel; the first rear-end voltage regulating module, the second rear-end voltage regulating module and the third rear-end voltage regulating module all include resistors and operational amplifiers, which are used to adjust the voltage and adjust the analog quantity collected by the front end to within the range of linear amplification of the operational amplifier of the rear-end isolation module.

[0013] In order to further realize more precise signal acquisition of current and voltage channels, the present invention provides a preferred solution, wherein the first back-end precision acquisition module, the second back-end precision acquisition module and the third back-end precision acquisition module include resistors, capacitors and instrument amplifiers, which are used to accurately acquire the analog quantity output by the isolation module op amp and amplify it to the acquisition range of AD sampling for AD sampling.

[0014] In order to achieve relatively precise acquisition of voltage channel analog quantities and overcurrent protection, the present invention provides a preferred solution, wherein the follower module includes a TVS tube, a voltage zener diode, a resistor, a capacitor and an operational amplifier. Overcurrent and overvoltage protection are performed through the TVS tube and the voltage zener diode, and the collected voltage analog quantities are accurately transmitted to the subsequent module through the resistor, the capacitor and the operational amplifier.

[0015] In a second aspect, the present invention provides a sampling and calibration method based on an electronic transformer, which adopts the above-mentioned sampling and calibration device, including: signal acquisition and conditioning, through a signal acquisition and conditioning device modularly integrated with a conditioning unit, arranged in a protection device and electrically connected to a central processing unit of the protection device, to acquire and condition the current analog small signal and / or voltage analog small signal output by the calibrated electronic transformer for AD sampling; test calibration, through a test calibrator to obtain and verify the analog signal output by a standard electronic transformer source and the SV data output by the central processing unit of the protection device, to provide the signal amplitude deviation and phase difference between the calibrated electronic transformer and the standard electronic transformer source for calibration; calibration, through a calibration device to communicate with the AD sampling module and the test calibrator of the protection device respectively, to calibrate the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator, to complete the online calibration of the data of the calibrated electronic transformer.

[0016] Compared with the prior art, the above technical solution has the following advantages:

[0017] The present invention proposes a plan to improve the anti-electromagnetic interference capability of small signal transmission of an electronic transformer, designs a modular signal acquisition and conditioning device integrated with a conditioning unit, which is arranged in a protection device to complete data acquisition of the electronic transformer, and condition the current or voltage collected by the electronic transformer into a range that can be collected by an AD sampling module, thereby improving the anti-electromagnetic interference capability of small current signal transmission from the electronic transformer to the protection device.

[0018] The sampling and calibration device of the present invention is based on an electronic mutual inductor, which improves the integration of the line protection device, simplifies the communication connection in the cabinet, reduces the number of communication optical fibers, eliminates the need to add separate acquisition equipment and merging units, reduces the manufacturing cost of the intelligent device, and is conducive to promotion and application.

[0019] The present invention is based on a sampling and calibration device for an electronic transformer, performs real-time online calibration through a human-machine menu in a protection device, simplifies the calibration scheme, improves the calibration efficiency of the electronic transformer, and can realize remote monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of a sampling and calibration device module based on an electronic mutual inductor according to Embodiment 1 of the present invention;

[0022] Figure 2 This is a flow chart of a sampling and calibration method based on an electronic mutual inductor according to Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of a sampling and calibration device module based on an electronic mutual inductor according to Embodiment 2 of the present invention.

[0024] Reference numerals: calibrated electronic transformer 100, standard electronic transformer source 200, protection device 300, signal acquisition and conditioning device 310, measurement current conditioning unit 311, front-end precision acquisition module 3111, first integration module 3112, first rear-end voltage regulation module 3113, first isolation module 3114, first rear-end precision acquisition module 3115, protection current conditioning unit 312, front-end voltage regulation module 3121, second integration module 3122, second rear-end voltage regulation module 3123, second isolation module 312 4. A second back-end precision acquisition module 3125, a voltage conditioning unit 313, a following module 3131, a third back-end voltage regulating module 3132, a third isolation module 3133, a third back-end precision acquisition module 3134, a central processing unit 320, a filtering module 321, an ADC analog-to-digital conversion module 322, an AD sampling module 323, a process layer acquisition module 324, a calibration device 330, a human-machine menu 331, a test calibrator 400, an analog signal acquisition unit 410, a digital signal acquisition unit 420, and a display unit 430. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] Please refer to Figure 1The present embodiment provides a sampling and calibration device 330 based on an electronic transformer, which is mainly based on a protection device 300 of an electronic transformer, wherein the protection device 300 has a built-in central processing unit 320 (CPU), and the central processing unit 320 is provided with a filtering module 321, an ADC analog-to-digital conversion module 322, an AD sampling module 323 and a process layer acquisition module 324, the process layer acquisition module 324 is used to perform process layer acquisition on the data sampled by AD and output SV data; the filtering module 321 is arranged before the ADC analog-to-digital conversion module 322, and is used to digitally filter the signal obtained from the signal acquisition and conditioning device 310 to filter the interference wave.

[0028] In this embodiment, the sampling calibration device 330 is mainly composed of a signal acquisition and conditioning device 310, a test calibrator 400 and a calibration device 330, wherein the signal acquisition and conditioning device 310 is modularly integrated with a conditioning unit, is arranged in the protection device 300 and is electrically connected to the central processor 320 of the protection device 300, and is used to collect and condition the current analog small signal and / or voltage analog small signal output by the calibrated electronic transformer for AD sampling. The test calibrator 400 is used to obtain and verify the analog signal output by the standard electronic transformer source 200 and the SV data output by the central processor 320 of the protection device 300, and provide the signal amplitude deviation and phase difference between the calibrated electronic transformer 100 and the standard electronic transformer source 200 for calibration. The calibration device 330 communicates with the AD sampling module 323 and the test calibrator 400, calibrates the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator 400, and completes the online calibration of the calibrated electronic transformer data.

[0029] Please refer to Figure 2The present invention adopts the above-mentioned sampling and calibration device 330 to provide a sampling and calibration method based on an electronic transformer, which mainly includes the following steps: S1 signal acquisition and conditioning, through a signal acquisition and conditioning device 310 modularly integrated with a conditioning unit, which is arranged in the protection device 300 and electrically connected to the central processor 320 of the protection device 300, to collect and condition the small current analog signal and / or voltage analog signal output by the calibrated electronic transformer for AD sampling. For signal conditioning, three channel conditioning schemes are given, namely, the measurement current conditioning scheme, the protection current conditioning scheme and the voltage conditioning scheme, and each conditioning scheme is implemented by the measurement current conditioning unit 311, the protection current conditioning unit 312 and the voltage conditioning unit 313 respectively. S2 test calibration, through a test calibrator 400 to obtain and verify the analog signal output by the standard electronic transformer source 200 and the SV data output by the central processor 320 of the protection device 300, and provide the signal amplitude deviation and phase difference between the calibrated electronic transformer 100 and the standard electronic transformer source 200 for calibration. S3 calibration, through a calibration device 330 to communicate with the AD sampling module 323 of the protection device 300 and the test calibrator 400 respectively, calibrate the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator 400, and complete the online calibration of the data of the calibrated electronic transformer.

[0030] In this embodiment, the signal acquisition and conditioning device 310 is preferably arranged in the protection device 300 in the form of an acquisition board, and can be inserted into the protection device 300 through a plug-in structure. The conditioning unit is integrated on the acquisition board, and is mainly composed of a measurement current conditioning unit 311, a protection current conditioning unit 312, and a voltage conditioning unit 313. Among them, the measurement current conditioning unit 311 is used to condition the measurement current signal on the current channel of the calibrated electronic transformer 100 before AD sampling, and to condition the protection current collected by the electronic transformer into the optimal range that AD can collect, so as to complete the collection of the protection current. The protection current conditioning unit 312 is used to condition the protection current signal on the current channel of the calibrated electronic transformer 100 before AD sampling, and to condition the measurement current collected by the electronic transformer into the optimal range that AD can collect, so as to complete the collection of the measurement current. The voltage conditioning unit 313 is used to condition the measurement voltage signal and the protection voltage signal on the voltage channel of the calibrated electronic transformer 100 before AD sampling, and to condition the voltage collected by the electronic transformer into the optimal range that can be collected by AD, thereby completing voltage collection.

[0031] In this embodiment, the same cable is passed through the standard electronic transformer source 200 and the calibrated electronic transformer 100, the analog signal output by the standard electronic transformer source 200 is connected to the test calibrator 400, the small signal output by the calibrated electronic transformer 100 is connected to the acquisition board of the protection device 300, and the SV data output by the protection device 300 is connected to the test calibrator 400. By checking the amplitude deviation and phase difference displayed in the calibration instrument, the amplitude and phase difference are calibrated in the LCD menu of the protection device 300, and the verification value is confirmed and saved to complete the electronic transformer data calibration.

[0032] This embodiment proposes a scheme to improve the anti-electromagnetic interference capability of small signal transmission of electronic transformers, solves the problem of weak anti-electromagnetic interference capability of the small current signal transmission link between the electronic transformer and the protection device 300, completes the data acquisition of the electronic transformer by designing a special acquisition board, and adjusts the current or voltage collected by the electronic transformer into the optimal range that the AD sampling module 323 can collect. The adjusted collected analog quantity is input to the AD end of the CPU board through the backplane, and the AD end is provided with a filter module 321 (RC filter circuit), an ADC analog-to-digital conversion module 322 and an AD sampling module 323. The filter module 321 mainly completes the digital filtering of the input analog signal.

[0033] In this embodiment, the test calibrator 400 has built-in analog signal acquisition unit 410, digital signal acquisition unit 420 and display unit 430. The protection current collected by the protection current channel, the measurement current collected by the measurement current channel and the voltage collected by the voltage channel are output from the process layer acquisition module 324 of the central processor 320 through the sampling calibration device 330, and are connected to the test calibrator 400 at the same time as the analog signal output by the standard electronic transformer source. The analog signal acquisition unit 410 of the test calibrator 400 receives the analog signal output from the standard electronic transformer source, and the digital signal acquisition unit 420 receives the SV data output from the central processor 320 of the protection device 300. The amplitude deviation and phase difference of the two are displayed through the display unit 430. The calibration personnel can check the amplitude deviation and phase difference displayed in the test calibrator 400, calibrate the amplitude and phase difference in the calibration device 330 of the protection device 300 (the human-machine menu 331 can be used), confirm and save the verification value, and complete the data calibration of the calibrated electronic transformer 100.

[0034] The sampling and calibration device 330 of the present embodiment is based on an electronic transformer, which improves the integration of the line (10 kV line) protection device 300, simplifies the communication connections in the cabinet, reduces the number of communication optical fibers (by more than half), eliminates the need to add separate collection equipment and merging units, reduces the manufacturing cost of intelligent equipment, and facilitates its promotion and application.

[0035] This embodiment is based on the sampling and calibration device 330 of the electronic transformer, and performs real-time online verification through the human-machine menu 331 in the protection device 300, simplifies the verification scheme, improves the verification efficiency of the electronic transformer, and can realize remote monitoring. Through the promotion and application of this invention, the application specification of the electronic transformer for 10 kV line protection is innovated.

[0036] This embodiment is based on a sampling and calibration device 330 of an electronic transformer, wherein the sampling device is arranged in the original protection device 300 in the form of an acquisition board, that is, the small signal of the electronic transformer is integrated into an acquisition board of the device, and the acquisition board can be inserted into the protection device 300 through a plug-in structure setting, so that maintenance and replacement are very convenient, and can even be operated when powered, thereby reducing or shortening the power outage time.

[0037] Example 2

[0038] Please refer to Figure 3 Based on Example 1, this embodiment provides a preferred implementation of the measurement current conditioning unit 311, a preferred implementation of the protection current conditioning unit 312, and a preferred implementation of the voltage conditioning unit 313.

[0039] The measuring current conditioning unit 311 is mainly composed of a front-end precision acquisition module 3111, a first integration module 3112, a first back-end voltage regulation module 3113, a first isolation module 3114 and a first back-end precision acquisition module 3115. The measuring current of the calibrated electronic transformer 100 is conditioned in turn by the above modules of the measuring current conditioning unit 311 and then provided for AD sampling.

[0040] The protection current conditioning unit 312 is mainly composed of a voltage regulating module, a second integration module 3122, a front-end voltage regulating module 3121, a second isolation module 3124 and a second back-end precision acquisition module 3125. The protection current of the calibrated electronic transformer 100 is conditioned by the above modules of the protection current conditioning unit 312 in sequence and then provided for AD sampling.

[0041] The voltage conditioning unit 313 is mainly composed of a following module 3131, a second rear-end voltage regulating module 3123, a third isolation module 3133 and a third rear-end precision acquisition module 3134. The measurement voltage and protection voltage of the calibrated electronic transformer 100 are conditioned in turn by the above modules of the voltage conditioning unit 313 and then provided for AD sampling, which mainly plays the role of over-current and over-voltage protection and more accurate acquisition of input analog quantities.

[0042] Among them, the front-end precision acquisition module 3111 is mainly composed of TVS tubes, voltage-stabilizing diodes, resistors, capacitors and instrument amplifiers. Overcurrent and overvoltage protection are performed through TVS tubes and voltage-stabilizing diodes, and the current analog quantity is more accurately collected and measured through resistors, capacitors and instrument amplifiers.

[0043] The first integral module 3112 and the second integral module 3122 are both provided with resistors, capacitors and operational amplifiers, which are used to restore the analog quantities of the measured current and the protection current after differential operation. The analog quantity inputted by the external electronic mutual inductor has undergone differential operation, and the function of this part is to use the integral circuit to restore the analog quantity after differential operation, so as to ensure the authenticity of the collected analog quantity.

[0044] In the protection current conditioning unit 312, a front-end voltage regulating module 3121 is provided to reduce the overload voltage of the protection current channel, which is a large voltage regulation. The measurement current conditioning unit 311, the protection current conditioning unit 312 and the voltage conditioning unit 313 are respectively provided with a first rear-end voltage regulating module 3113, a second rear-end voltage regulating module 3123 and a third rear-end voltage regulating module 3132 at the rear end (before the isolation module), and all include resistors and operational amplifiers, which are used to adjust the voltage, which is a fine voltage regulation, and adjusts the analog quantity collected by the front end to the range of the linear amplification of the operational amplifier of the rear-end isolation module. Because the protection current requirement is 20 times overload, and the measurement current is 1.5 times, the protection current first undergoes a large voltage reduction when it comes in, and then fine-tunes to the collection range of the second rear-end precision acquisition module 3125. In other words, the overload multiple of the protection current is large, and the front is first subjected to a large voltage regulation, and the voltage regulation at the back is fine-tuning.

[0045] The first back-end precision acquisition module 3115, the second back-end precision acquisition module 3125 and the third back-end precision acquisition module 3134 are provided with resistors, capacitors and instrument amplifiers for accurately acquiring the analog quantity output by the isolation module operational amplifier and amplifying it to a suitable acquisition range for AD sampling for AD sampling.

[0046] The first isolation module 3114, the second isolation module 3124 and the third isolation module 3133 are mainly composed of resistors, capacitors and isolation amplifiers, and play a role of protection isolation, isolating the front end and the back end, and effectively protecting the back end core circuit from the destructive influence of the front end.

[0047] The follower module 3131 is provided with a TVS tube, a voltage stabilizing diode, a resistor, a capacitor and an operational amplifier. Overcurrent and overvoltage protection is performed through the TVS tube and the voltage stabilizing diode, and the collected voltage analog quantity is accurately transmitted to the subsequent module through the resistor, the capacitor and the operational amplifier.

[0048] In this embodiment, a more preferred improvement scheme is proposed for the anti-electromagnetic interference capability of small signal transmission, so as to solve the problem of weak anti-electromagnetic interference capability of the small current signal transmission link between the electronic transformer and the protection device 300. Based on the dedicated acquisition board designed in Example 1, not only the data acquisition of the electronic transformer is completed, but also the current (integration required) or voltage (no integration required) collected by the electronic transformer is adjusted to the optimal range that AD can collect, and a front-end precision acquisition module 3111 of a TVS tube and a diode is set at the front end of the acquisition board to play a protective role, and an operational amplifier isolation circuit (isolation module) is designed at the back end to play an isolation role between the front and back ends, and the conditioned collected analog quantity is input to the AD terminal in the central processing unit 320 (CPU) through the backplane of the protection device 300.

[0049] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A sampling and calibration device based on an electronic mutual inductor, characterized in that: The protection device based on electronic mutual inductor has a built-in central processor, which is provided with an ADC analog-to-digital conversion module, an AD sampling module and a process layer acquisition module. The process layer acquisition module is used to perform process layer acquisition on the data sampled by AD and output SV data. The sampling calibration device comprises: The signal acquisition and conditioning device is modularly integrated with a conditioning unit, is arranged in the protection device and is electrically connected to the central processing unit of the protection device, and is used to acquire and condition the small current analog signal and / or voltage analog signal output by the calibrated electronic transformer for AD sampling; The test calibrator is used to obtain and verify the analog signal output by the standard electronic transformer source and the SV data output by the central processor of the protection device, and provide the signal amplitude deviation and phase difference between the calibrated electronic transformer and the standard electronic transformer source for calibration; The calibration device communicates with the AD sampling module and the test calibrator of the protection device respectively, calibrates the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator, and completes the online calibration of the data of the calibrated electronic transformer.

2. The sampling and calibration device based on electronic mutual inductor according to claim 1 is characterized in that: The signal acquisition and conditioning device adopts the form of an acquisition board, and the conditioning unit is integrated on the acquisition board, including: a measuring current conditioning unit, which is used to condition the measuring current signal on the current channel of the calibrated electronic transformer before AD sampling; a protection current conditioning unit, which is used to condition the protection current signal on the current channel of the calibrated electronic transformer before AD sampling; and a voltage conditioning unit, which is used to condition the measuring voltage signal and the protection voltage signal on the voltage channel of the calibrated electronic transformer before AD sampling.

3. The sampling and calibration device based on electronic mutual inductor according to claim 2 is characterized in that: The measuring current conditioning unit comprises a front-end precision acquisition module, a first integration module, a first rear-end voltage regulation module, a first isolation module and a first rear-end precision acquisition module. The measuring current of the calibrated electronic transformer is sequentially conditioned by the above modules of the measuring current conditioning unit and then supplied to AD sampling. The protection current conditioning unit includes a voltage regulating module, a second integration module, a front-end voltage regulating module, a second isolation module and a second rear-end precision acquisition module. The protection current of the calibrated electronic transformer is conditioned by the above modules of the protection current conditioning unit in sequence and then supplied to AD sampling. The voltage conditioning unit includes a following module, a second rear-end voltage regulating module, a third isolation module and a third rear-end precision acquisition module. The measured voltage and protection voltage of the calibrated electronic transformer are conditioned in turn by the above modules of the voltage conditioning unit and then provided for AD sampling.

4. The sampling and calibration device based on electronic mutual inductor according to claim 3 is characterized in that: The front-end precision acquisition module includes a TVS tube, a voltage-stabilizing diode, a resistor and a capacitor, and an instrument amplifier. Overcurrent and overvoltage protection are performed through the TVS tube and the voltage-stabilizing diode, and the resistor and the capacitor and the instrument amplifier are used to more accurately acquire and measure the current analog quantity.

5. The sampling and calibration device based on electronic mutual inductor according to claim 3 is characterized in that: The first integration module and the second integration module both include resistors, capacitors and operational amplifiers, and are used to restore the analog quantities of the measured current and the protection current that have undergone differential operations.

6. The sampling and calibration device based on electronic mutual inductor according to claim 3 is characterized in that: The front-end voltage regulating module is used to reduce the overload voltage of the protection current channel; the first rear-end voltage regulating module, the second rear-end voltage regulating module and the third rear-end voltage regulating module all include resistors and operational amplifiers, which are used to adjust the voltage and adjust the analog quantity collected by the front end to within the range of linear amplification of the operational amplifier of the rear-end isolation module.

7. The sampling and calibration device based on electronic mutual inductor according to claim 3 is characterized in that: The first back-end precision acquisition module, the second back-end precision acquisition module and the third back-end precision acquisition module include resistors, capacitors and instrument amplifiers, which are used to accurately acquire the analog quantity output by the isolation module operational amplifier and amplify it to the acquisition range of AD sampling for AD sampling.

8. The sampling and calibration device based on electronic mutual inductor according to claim 3 is characterized in that: The follower module includes a TVS tube, a voltage-stabilizing diode, a resistor, a capacitor and an operational amplifier. Overcurrent and overvoltage protection is performed through the TVS tube and the voltage-stabilizing diode, and the collected voltage analog quantity is accurately transmitted to the subsequent module through the resistor, the capacitor and the operational amplifier.

9. The sampling and calibration device based on electronic mutual inductor according to claim 1, characterized in that: The central processor also includes a filtering module, which is arranged before the ADC analog-to-digital conversion module and is used to digitally filter the signal obtained from the signal acquisition and conditioning device and filter the interference wave.

10. A sampling and calibration method based on an electronic mutual inductor, using the sampling and calibration device according to any one of claims 1 to 9, characterized in that: include: Signal acquisition and conditioning, through a signal acquisition and conditioning device modularly integrated with a conditioning unit, arranged in the protection device and electrically connected to the central processor of the protection device, to acquire and condition the current analog small signal and / or voltage analog small signal output by the calibrated electronic transformer for AD sampling; Test calibration, using a test calibrator to obtain and verify the analog signal output by the standard electronic transformer source and the SV data output by the central processor of the protection device, and provide the signal amplitude deviation and phase difference between the calibrated electronic transformer and the standard electronic transformer source for calibration; Calibration: A calibration device communicates with the AD sampling module and the test calibrator of the protection device respectively, and calibrates the amplitude and phase of the AD sampling signal according to the signal amplitude deviation and phase difference data provided by the test calibrator to complete the online calibration of the data of the calibrated electronic transformer.

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