Transformer assembly and implementation method and use method thereof without secondary calibration

Abstract

The embodiment of the present application provides a transformer assembly and a method for implementing and using the transformer assembly without secondary calibration. The structure of the transformer assembly is improved, and the improved transformer assembly is combined with a standard metering core and installed in a standard circuit for calibration, and the obtained calibration parameters are stored in the transformer assembly in advance, so that it can be directly combined with the metering core when used on site without the need for secondary calibration of the transformer. The transformer without secondary calibration implementation method can greatly increase the versatility of current transformer components, and can achieve that the reorganized equipment meets certain accuracy requirements without secondary calibration of the transformer, reducing maintenance costs, etc.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a mutual inductor assembly and a method for realizing and using the assembly without secondary calibration. Background Art

[0002] At present, in the low-voltage electrical industry, the solution of metering chip plus current transformer is generally used to measure the electricity. However, because the metering chips, sampling resistors, and current transformers from different batches and manufacturers will affect the overall metering accuracy, the overall equipment must be calibrated to ensure that the accuracy of the equipment meets certain requirements. However, when the on-site current transformer is in a state of insulation aging, abnormal open circuit, overload and long-term operation, etc., it may cause the current transformer to be inaccurate or even burned. In view of the above problems, the overall equipment or the damaged current transformer must be replaced to ensure the normal use of the equipment. In order to reduce the time cost and equipment cost of replacement, a solution of replacing only the transformer is proposed. However, after replacing the current transformer, due to the magnetic resistance of the core of the current transformer, it must consume a part of the current for excitation to magnetize the core, thereby generating an induced potential and secondary current on the secondary side. Different current transformers have different excitation currents and iron losses, resulting in the difference between the primary current and the secondary current of the current transformer being not fixed, but a vector, and the error includes ratio difference and phase angle difference. Therefore, after replacing the current transformer on site, a secondary calibration must be performed to ensure a certain measurement accuracy.

[0003] There are two main on-site solutions for the above problems: one is to recalibrate the reassembled equipment; the other is to replace the equipment as a whole. Although both solutions can ensure the measurement accuracy after replacing the equipment, the first solution requires portable calibration equipment for on-site calibration, and on-site calibration is complicated, time-consuming and labor-intensive. The second solution of the overall replacement increases maintenance costs, and undamaged components cannot be used again, resulting in unnecessary waste. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a transformer assembly and an implementation method and a use method thereof that do not require secondary calibration. The implementation method that does not require secondary calibration is based on an improved transformer assembly, which can achieve measurement accuracy without the need for secondary calibration when used on site, greatly reducing maintenance costs.

[0005] An embodiment of the present application provides a transformer assembly, comprising: a voltage access terminal, a current limiting resistor, a voltage sampling resistor, a current transformer, a current sampling resistor, a storage module and a first connection terminal;

[0006] The voltage access terminal, the current limiting resistor and the voltage sampling resistor are connected in sequence, the current transformer is connected to the current sampling resistor, the voltage access terminal, the voltage sampling resistor, the current sampling resistor and the storage module are respectively connected to the first connection terminal, and the first connection terminal is used to cooperate with the second connection terminal of the target calibration-free metering core component to realize signal interaction.

[0007] The embodiment of the present application further provides a method for realizing a transformer without secondary calibration, wherein the transformer adopts the above-mentioned transformer assembly, and the transformer assembly is combined with a standard metering core to obtain a combined device, which is then installed in a standard circuit. The implementation method includes:

[0008] Inputting a first standard signal whose voltage and current are in phase to the standard line, and calculating a voltage ratio difference calibration parameter according to the voltage of the first standard signal and the actual voltage measured by the combined device, and calculating a current ratio difference calibration parameter according to the current of the first standard signal and the actual current measured by the device;

[0009] Inputting a second standard signal having a phase difference between voltage and current into the standard line, and calculating a phase difference calibration parameter according to the voltage, current and phase difference of the second standard signal and the actual power measured by the combined device, wherein the phase difference is not zero;

[0010] The voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are stored in the storage module of the mutual inductor component to be used as the whole machine calibration parameter when it is subsequently combined with the metering core component.

[0011] In some embodiments, the voltage ratio calibration parameter is calculated as follows:

[0012] Ui=C u *(Uc-Un) / Un;

[0013] Wherein, Ui represents the voltage ratio calibration parameter, Uc represents the actual voltage, Un represents the voltage of the first standard signal, C u It is the voltage ratio difference adjustment value.

[0014] In some embodiments, the calculation formula of the current ratio difference calibration parameter is as follows:

[0015] Ii=C I *(Ic-In) / In;

[0016] Wherein, Ii represents the current ratio calibration parameter, Ic represents the actual current, In represents the current of the first standard signal, C I is the current ratio difference adjustment value.

[0017] In some embodiments, the voltage and current amplitudes of the second standard signal are correspondingly equal to the voltage and current amplitudes of the first standard signal;

[0018] The calculation formula of the phase difference calibration parameter is as follows:

[0019] Phi=C ph *(Wc-cosΦ*Un*In) / (cosΦ*Un*In);

[0020] Wherein, Phi represents the phase difference calibration parameter, Wc represents the actual power, cosΦ represents the power factor corresponding to the second standard signal when the second phase difference is present, Un and In represent the voltage and current of the first standard signal respectively, and C ph is the phase difference adjustment value.

[0021] The embodiment of the present application further provides a method for using a transformer without secondary calibration. After the transformer assembly obtained by the above implementation method is combined with a calibration-free metering core assembly into a measuring device, the method for using includes:

[0022] The voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are read from the storage module of the transformer assembly, and written into the calibration-free metering core assembly as the whole-machine calibration parameters of the measuring device. The whole-machine calibration parameters are used to calibrate the metering data obtained by the calibration-free metering core assembly to obtain the final metering data.

[0023] In some embodiments, the writing into the calibration-free metering core assembly also includes:

[0024] Detecting whether the voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are correct;

[0025] When the correctness is detected, the writing operation is executed;

[0026] When an inaccuracy is detected, a calibration parameter error is prompted and a zero value is written into the calibration-free metering core assembly.

[0027] An embodiment of the present application further provides a measuring device, comprising: a mutual inductor and a calibration-free measuring core that is pluggable with the mutual inductor, and the measuring device implements the above-mentioned method of use.

[0028] In some embodiments, the measuring device is a pluggable electric energy meter or a rail meter.

[0029] An embodiment of the present application further provides a readable storage medium storing a computer program, wherein the computer program implements the above method when executed on a processor.

[0030] The embodiments of the present application have the following beneficial effects:

[0031] The transformer assembly of the embodiment of the present application is improved in structure, wherein, in addition to the current transformer, a current limiting resistor, a sampling resistor, etc. are also provided, and the improved transformer assembly is combined with a standard metering core and installed in a standard circuit for calibration, and the obtained calibration parameters are stored in the transformer assembly in advance, so that it can be directly combined with the metering core when used on site, without the need for secondary calibration of the transformer. While calibrating the current transformer, the errors of these resistors are also taken into account, and when it is combined with a calibration-free metering core, the metering accuracy of the transformer can also be well guaranteed. In addition, the implementation method of the transformer without secondary calibration can greatly increase the versatility of the current transformer components, and the reorganized equipment can meet certain accuracy requirements without secondary calibration of the transformer, reducing maintenance costs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic structural diagram of a mutual inductor assembly according to an embodiment of the present application is shown;

[0034] Figure 2 A schematic structural diagram of a calibration-free metering core assembly according to an embodiment of the present application is shown;

[0035] Figure 3 A first flow chart of a method for implementing a mutual inductor without secondary calibration according to an embodiment of the present application is shown;

[0036] Figure 4 A schematic diagram of an application of a calibration platform according to an embodiment of the present application is shown;

[0037] Figure 5 A first flow chart showing a method for using a transformer without secondary calibration according to an embodiment of the present application is shown;

[0038] Figure 6 A second flow chart of the method for using a transformer without secondary calibration according to an embodiment of the present application is shown.

[0039] Description of main component symbols:

[0040] 100 - transformer assembly; 110 - current transformer; 120 - voltage access terminal; R1 - current limiting resistor; R2 - voltage sampling resistor; R3 - current sampling resistor; 130 - storage module; J1 - first connection terminal;

[0041] 200 - metering core assembly; 210 - power processing unit; 220 - metering chip; 230 - main control chip; J2 - second connection terminal. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0043] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0044] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing items.

[0045] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0046] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0047] Example 1

[0048] Please refer to Figure 1This embodiment provides a mutual inductor assembly 100, which can be applied to current measurement occasions of various low-voltage lines, such as single-phase AC lines, three-phase AC lines, etc.

[0049] For example, Figure 1 As shown, the transformer assembly 100 includes a current transformer 110, a voltage access terminal 120, a current limiting resistor R1, a voltage sampling resistor R2, a current sampling resistor R3, a storage module 130 and a first connection terminal J1, wherein the voltage access terminal 120, the current limiting resistor R1 and the voltage sampling resistor R2 are connected in sequence, the current transformer 110 is connected to the current sampling resistor R3, and the voltage access terminal 120, the voltage sampling resistor R2, the current sampling resistor R3 and the storage module 130 are respectively connected to the first connection terminal J1.

[0050] The above-mentioned current transformer 110 is mainly used to collect the current signal in the main circuit where the measured line is located, and then converted into a small voltage signal by the current sampling resistor R3, and then sent to the calibration-free metering core component 200 for signal processing. It can be understood that when the measured line is a single-phase line, the number of the current transformer 110 is 1; if it is a three-phase line, it can include 3 current transformers 110, that is, each phase line is installed with a current transformer 110 for current collection.

[0051] The voltage sampling terminal is mainly used to access the AC voltage signal of the measured circuit, and then transmit it to the calibration-free metering core component 200 through the connection terminal. The current limiting resistor R1 is mainly used to limit the current of the AC voltage signal, and is also used to convert the voltage signal into a small current signal, which is then converted into a small voltage signal by the voltage sampling resistor R2 and then sent to the calibration-free metering core component 200 for signal processing.

[0052] In this embodiment, the storage module 130 is integrated with the current transformer 110 and other main components to form the transformer assembly 100, and is mainly used to store calibration data when calibrating the transformer assembly 100. For example, the storage module 130 includes but is not limited to a memory with a power-off storage function such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a FRAM (Ferroelectric RAM).

[0053] It can be understood that by adding a storage module 130 to the transformer assembly 100, it is used to store the transformer calibration parameters obtained when the current transformer 110 is calibrated in advance. This makes it convenient for the main control of the metering core assembly 200 to access and read the transformer calibration parameters when it is subsequently combined with the metering core assembly 200, thereby achieving secondary calibration-free operation of the transformer assembly 100 during reorganization.

[0054] In this embodiment, the first connecting terminal J1 is used in conjunction with the second connecting terminal J2 of the target calibration-free metering core assembly 200 to realize signal interaction between the transformer assembly 100 and the metering core assembly 200. Specifically, it serves as a channel for AC power supply, power supply, voltage signal, current signal and storage chip communication line between the metering core assembly 200 and the transformer assembly 100.

[0055] Among them, for the first connection terminal J1, in one embodiment, a connector with a plug-in structure can be used to implement it. For example, when the first connection terminal J1 of the transformer assembly 100 adopts a male connector for use in conjunction with it, the corresponding second connection terminal J2 of the metering core assembly 200 will adopt a female connector, and vice versa, which is not limited here.

[0056] It is worth noting that, in addition to the current transformer 110, the transformer assembly 100 of this embodiment is also provided with a current limiting resistor R1, a sampling resistor, etc. In addition to the deviation of the current transformer 110 itself, each resistor may also be inconsistent with the calibrated value due to the yield rate, etc. When the current transformer 110 is calibrated, the errors of these resistors are also taken into account. When it is combined with a calibration-free metering core, the metering accuracy of the transformer can also be well guaranteed. Among them, the calibration-free metering core means that the metering chip 220 supplier has been calibrated before leaving the factory, and the accuracy of the metering chip 220 itself is not less than 1%.

[0057] It can be understood that after these resistors are integrated into the transformer assembly 100, the calibration-free metering core combined therewith does not need to be equipped with these resistors additionally, and thus can be obtained by using a universal standard metering chip 220 or the like. Figure 2 Shown is a schematic structural diagram of a calibration-free metering core assembly 200 .

[0058] Exemplarily, the calibration-free metering core assembly 200 mainly includes a metering chip 220, a main control chip 230 and a power processing unit 210 respectively connected to the second connection terminal J2. Figure 2 As shown. The power processing unit 210 is mainly used for power supply. Specifically, it takes power from the measured circuit through the docking connection terminal and converts it into a low-voltage DC power supply to provide the required working voltage for the metering chip 220, the main control chip 230, etc. The metering chip 220 and the main control chip 230 can be used to calculate the above-mentioned current signal and voltage signal obtained by the transformer assembly 100, so as to obtain the corresponding metering data. Optionally, the calibration-free metering core assembly 200 can be a Figure 2The solution of the main control chip 230 (MCU) plus a separate metering chip 220 shown may also adopt a system-on-chip (SOC) chip solution with metering function, or may be a main control MCU with multi-channel high-precision analog-to-digital conversion (ADC) function, etc., which is not limited here.

[0059] Example 2

[0060] Please refer to Figure 3 and Figure 4 Based on the above structure of the transformer assembly 100, the embodiment of the present application also proposes a method for realizing transformer free of secondary calibration. Exemplarily, the method for realizing transformer free of secondary calibration is applied to the host computer of the calibration platform. After the combination device is obtained by combining the above structure of the transformer assembly 100 with the standard metering core, as shown in FIG. Figure 4 As shown, it is installed in the standard circuit of the calibration platform, and the calibration platform calibrates the combined equipment. This calibration can be used as a basic calibration before leaving the factory. After this calibration, no secondary calibration is required during subsequent use.

[0061] For example, Figure 3 As shown, the method for implementing the transformer without secondary calibration includes:

[0062] Step S110, input a first standard signal with the same phase of voltage and current into the standard line, calculate the voltage ratio difference calibration parameter according to the voltage of the first standard signal and the actual voltage measured by the combination device, and calculate the current ratio difference calibration parameter according to the current of the first standard signal and the actual current measured by the device.

[0063] For step S110, exemplarily, in one implementation, the voltage ratio difference calibration parameter may be calculated according to the following calculation formula:

[0064] Ui=C u *(Uc-Un) / Un;

[0065] Wherein, Ui represents the voltage ratio calibration parameter of the transformer assembly 100, Uc represents the actual voltage measured by the combined device, Un represents the voltage of the first standard signal input by the calibration platform, and C u It is the voltage ratio difference adjustment value.

[0066] Similarly, in one implementation, the current ratio difference calibration parameter may be calculated according to the following calculation formula:

[0067] Ii=C I *(Ic-In) / In;

[0068] Wherein, Ii represents the current ratio calibration parameter of the transformer assembly 100, Ic represents the actual current measured by the combined device, In represents the current magnitude of the first standard signal input by the calibration platform, and C I is the current ratio difference adjustment value.

[0069] Step S120, inputting a second standard signal having a phase difference between voltage and current into the standard line, calculating a phase difference calibration parameter according to the voltage, current and the phase difference of the second standard signal and the actual power measured by the combined device, wherein the phase difference is not zero.

[0070] Among them, the difference between the first standard signal and the second standard signal mentioned above is only that the phase difference between the voltage and current of the standard signal input twice is different, while the amplitude of the signal is unchanged, that is, the magnitude of the voltage and current of the first standard signal is respectively equal to the magnitude of the voltage and current of the second standard signal. For the convenience of calculation, in this embodiment, the voltage and current of the signal input for the first time are in phase, and the corresponding power factor is 1.0; and for the second time, a standard signal with a non-zero phase difference is input, for example, the phase difference between the voltage and the current can be selected to be 60° when the current lags behind the voltage, and the power factor at this time is 0.5. Of course, a signal in which the voltage lags behind the current by a preset angle can also be selected, which is not limited here.

[0071] For step S120, illustratively, the phase difference calibration parameter may be calculated according to the following calculation formula:

[0072] Phi=C ph *(Wc-cosΦ*Un*In) / (cosΦ*Un*In);

[0073] Wherein, Phi represents the phase difference calibration parameter, Wc represents the actual power, cosΦ represents the power factor corresponding to the second standard signal when the second phase difference is present, for example, it can be 0.5, etc.; since the amplitude of the standard signal input twice remains unchanged, Un and In represent the voltage and current of the first standard signal or the second standard signal respectively, C ph is the phase difference adjustment value.

[0074] It can be understood that for the above voltage ratio difference adjustment value C u , current ratio difference adjustment value C I And the phase difference adjustment value C ph , which can be selected according to actual needs. In this embodiment, since the results of the above-mentioned calibration parameters may be positive or negative, for example, a 2-byte number with a sign bit can be used here to represent the value of the calibration parameter. Of course, other byte numbers can also be used to represent it, which will affect the values ​​of the above-mentioned adjustment values ​​accordingly. For example, the current ratio adjustment value C IFor example, when a signed 2-byte (16-bit) is used to represent the above current ratio calibration parameter, its value range is (-32768 to 32767). At this time, the adjustment value C I The value to be selected is 32768.

[0075] It should be understood that the execution order of steps S110 and S120 is not strictly limited. For example, the calculation operation of the above-mentioned calibration parameters can also be calculated simultaneously after two signal inputs, or can be calculated at the first signal input. There is no limitation here.

[0076] Step S130 , storing the voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter in the storage module 130 of the transformer assembly 100 , so as to serve as the whole machine calibration parameter when it is subsequently combined with the meter core assembly 200 .

[0077] Exemplarily, after calculating the voltage ratio difference calibration parameters, current ratio difference calibration parameters, phase difference calibration parameters, etc., the calibration platform can write them into the storage module 130 of the transformer assembly 100 through the main control of the standard metering core. When the transformer assembly 100 needs to be replaced, the pre-stored standard parameters can be directly used to adjust the metering data without the need for secondary standardization after reorganization.

[0078] Example 3

[0079] Please refer to Figure 5 Based on the method of the above embodiment 2, this embodiment proposes a method for using a transformer without secondary calibration. In actual use, the transformer assembly 100 obtained by the above method can be combined with the calibration-free metering core assembly 200 as needed to obtain a measuring device for electricity metering.

[0080] Exemplarily, the method for using the transformer without secondary calibration includes:

[0081] Step S210, reading the voltage ratio calibration parameter, the current ratio calibration parameter and the phase difference calibration parameter from the storage module 130 of the transformer assembly 100, and writing them into the calibration-free metering core assembly 200 as the whole machine calibration parameters of the measuring device.

[0082] Exemplarily, when the transformer component 100 is connected to the calibration-free metering core component 200 through the first connection terminal J1 and the second connection terminal J2, the main control unit in the calibration-free metering core component 200 will serve as the main control unit of the measuring device. Specifically, after the device is powered on and initialized, the calibration-free metering core component 200 will read the pre-stored standard parameters from the storage module 130 of the transformer component 100, and use it as the calibration parameters of the whole machine, and then enter the main program for subsequent adjustment of the measurement data.

[0083] Furthermore, if Figure 6 As shown, in the above step S210, after reading the standard parameters from the storage module 130 of the transformer assembly 100, the method further includes:

[0084] Check whether the voltage ratio calibration parameters, current ratio calibration parameters and phase difference calibration parameters are correct, and perform a write operation when they are detected to be correct. After the program runs normally, the main control chip 230 reads the intermediate parameters such as voltage, current, power, electricity, power factor, frequency, etc. of the metering chip 220 and calculates the real-time voltage, real-time current, real-time power, accumulated electricity, real-time power factor, real-time frequency and other values. On the contrary, when an incorrect value is detected, it prompts that the calibration parameter is wrong, and writes a zero value into the calibration-free metering core assembly 200. For example, it can be determined by detecting whether these standard parameters are zero, and when they are not zero, it is determined that the standard data is written correctly, otherwise it is determined that it is not written correctly.

[0085] The embodiment of the present application also provides a measuring device, which exemplarily includes: a mutual inductor and a calibration-free metering core pluggable with the mutual inductor, wherein the measuring device is used to implement the method described in the above embodiment 3 to determine the whole machine calibration parameters. Then, the whole machine calibration parameters are used to calibrate the metering data obtained by the calibration-free metering core assembly 200, so as to obtain accurate final metering data.

[0086] The measuring device obtained by the above combination can be applied to all measuring devices with pluggable metering cores, for example, including but not limited to electric energy meters, guide rail meters, digital display meters or measurement modules.

[0087] The present application also provides a readable storage medium storing a computer program, which, when executed on a processor, implements the method described in the above embodiment 2 or 3.

[0088] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow diagram, and the combination of boxes in the structure diagram and / or the flow diagram, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0089] In addition, the functional modules or units in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0090] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.

[0091] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for realizing a mutual inductor without secondary calibration, characterized in that: The transformer includes a transformer assembly, which includes: a voltage access terminal, a current limiting resistor, a voltage sampling resistor, a current transformer, a current sampling resistor, a storage module and a first connection terminal; the voltage access terminal, the current limiting resistor and the voltage sampling resistor are connected in sequence, the current transformer is connected to the current sampling resistor, and the voltage access terminal, the voltage sampling resistor, the current sampling resistor and the storage module are respectively connected to the first connection terminal; the transformer assembly is combined with a standard metering core through the first connection terminal to obtain a combined device and then installed in a standard circuit, and the implementation method includes: Inputting a first standard signal whose voltage and current are in phase to the standard line, and calculating a voltage ratio difference calibration parameter according to the voltage of the first standard signal and the actual voltage measured by the combined device, and calculating a current ratio difference calibration parameter according to the current of the first standard signal and the actual current measured by the combined device; Inputting a second standard signal having a phase difference between voltage and current into the standard line, and calculating a phase difference calibration parameter according to the voltage, current and phase difference of the second standard signal and the actual power measured by the combined device, wherein the phase difference is not zero; The voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are stored in the storage module of the transformer assembly to serve as the whole machine calibration parameters when it is subsequently combined with the calibration-free metering core assembly; the whole machine calibration parameters are used to calibrate the metering data obtained by the calibration-free metering core assembly to obtain the final metering data.

2. The method for realizing mutual inductor secondary calibration-free according to claim 1, characterized in that: The calculation formula of the voltage ratio difference calibration parameter is as follows: Ui=C u *(Uc-Un) / Un; Wherein, Ui represents the voltage ratio calibration parameter, Uc represents the actual voltage, Un represents the voltage of the first standard signal, C u It is the voltage ratio difference adjustment value.

3. The method for realizing mutual inductor secondary calibration-free according to claim 1, characterized in that: The calculation formula of the current ratio difference calibration parameter is as follows: Ii=C I *(Ic-In) / In; Wherein, Ii represents the current ratio calibration parameter, Ic represents the actual current, In represents the current of the first standard signal, C I is the current ratio difference adjustment value.

4. The method for realizing a mutual inductor without secondary calibration according to any one of claims 1 to 3, characterized in that: The voltage and current amplitudes of the second standard signal are correspondingly equal to the voltage and current amplitudes of the first standard signal; The calculation formula of the phase difference calibration parameter is as follows: Phi=C ph *(Wc-cosΦ*Un*In) / (cosΦ*Un*In); Wherein, Phi represents the phase difference calibration parameter, Wc represents the actual power, cosΦ represents the power factor corresponding to the second standard signal when the second phase difference is present, Un and In represent the voltage and current of the first standard signal respectively, C ph is the phase difference adjustment value.

5. A method for using a mutual inductor without secondary calibration, characterized in that: After the mutual inductor assembly obtained by the implementation method according to any one of claims 1 to 4 is combined into a measuring device through a first connecting terminal and a calibration-free metering core assembly, the use method includes: The voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are read from the storage module of the transformer assembly, and written into the calibration-free metering core assembly as the whole-machine calibration parameters of the measuring device. The whole-machine calibration parameters are used to calibrate the metering data obtained by the calibration-free metering core assembly to obtain the final metering data.

6. The method for using a mutual inductor without secondary calibration according to claim 5, characterized in that: The writing into the calibration-free metering core assembly also includes: Detecting whether the voltage ratio difference calibration parameter, the current ratio difference calibration parameter and the phase difference calibration parameter are correct; When the correctness is detected, the writing operation is executed; When an inaccuracy is detected, a calibration parameter error is prompted and a zero value is written into the calibration-free metering core assembly.

7. A measuring device, characterized in that: include: A mutual inductor and a calibration-free metering core that is pluggable with the mutual inductor, and the measuring device implements the method of use as described in claim 5 or 6.

8. The measuring device according to claim 7, characterized in that The measuring device is a pluggable electric energy meter or a rail meter.

9. A readable storage medium, characterized in that: The device stores a computer program, which, when executed on a processor, implements the method according to any one of claims 1 to 6.

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