CN111896906A - Method and device for correcting error calibration data of mutual inductor - Google Patents

Abstract

A method and a device for correcting error calibration data of a mutual inductor are provided, the method comprises the following steps: receiving a correction instruction for correcting error calibration data of the mutual inductor; acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from a plurality of correction algorithms according to the type of the mutual inductor and a preset corresponding rule; and acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data. According to the method and the device provided by the embodiment of the invention, the influence of the test environment on the error is increased on the original error calibration test data of the mutual inductor, and the reliability and the accuracy of the calibration data are greatly improved.

Description

Method and device for correcting error calibration data of mutual inductor

Technical Field

The invention relates to the field of power grid operation and maintenance, in particular to a method and a device for correcting error calibration data of a mutual inductor.

Background

With the rapid development of the internet technology, the internet of things technology has been widely applied to various industries of national economy in China, and forms a large pattern of coordination work of object-to-object perception, interconnection, intelligence and the like. However, in the face of modern construction of power grids, the on-site checking work level of the error of the transformer still stays at the level of 90 s in the last century. An instruction manual for developing field transformer error calibration work is written in the last 90 years, and is not modified after being used for more than 20 years, because the field transformer error calibration work is not changed in technology among 20 years.

In the face of improvement of the voltage grade of a power grid and increase of the transmission capacity, the manufacturing technology of the mutual inductor is rapidly advanced, great progress is made in structural design and process manufacturing, and related test technologies are not updated, so that the accuracy and reliability of error calibration data of the mutual inductor on site are questioned by more and more people. A large amount of researches and field tests find that the field mutual inductor error calibration test is greatly influenced by test environment, the environmental temperature, the power supply frequency, the test wiring mode, the placement positions of surrounding equipment and the like all influence the mutual inductor error result, and the reliability of the field mutual inductor error calibration data is seriously influenced by the influence degree even on the same order of magnitude as the mutual inductor error data.

Disclosure of Invention

In view of this, the invention provides a method and a device for correcting error calibration data of a transformer, and aims to solve the problem of low reliability of the error calibration data of the transformer caused by a test environment.

In a first aspect, an embodiment of the present invention provides a method for correcting error calibration data of a transformer, including: receiving a correction instruction for correcting error calibration data of the mutual inductor; acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from a plurality of correction algorithms according to a preset corresponding rule according to the type of the mutual inductor; and acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data.

Further, the correction algorithm comprises: a standard device correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

Further, when the selected correction algorithm relates to an external electric field correction algorithm, acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, including: acquiring test environment parameters and transformer parameters of a transformer error calibration test; using the test environment parameters and the transformer parameters, and using a pre-established external electric field correction model to simulate and obtain a ratio difference f generated by an external electric field interference object_c(ii) a Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting a ratio difference f generated by the external electric field interferent from the error calibration data_cObtaining corrected error calibration data; wherein, experimental environmental parameters of mutual-inductor error calibration test include: whether an external electric field interference object exists around, and the distance between the external electric field interference object and the mutual inductor; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Lower, lowerVoltage capacitance C₂And a nominal primary voltage.

Further, the external electric field correction model is previously established as follows: constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters; acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is a ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is a ratio difference generated by the external electric field interferent simulated by the initial model; and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

Further, when the selected correction algorithm relates to a standard correction algorithm, acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, including: acquiring test environment parameters of a transformer error calibration test and error calibration data of the transformer directly acquired by the error calibration test; deducting the test environment parameters from the error calibration data to obtain corrected error calibration data; wherein the test environment parameter is the ratio difference f of the current transformer of the standard instrument under the rated current and full load_{Sign board}Phase difference of sum_{Sign board}。

Further, when the selected correction algorithm relates to a secondary load correction algorithm, acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, including: acquiring test environment parameters of a mutual inductor error calibration test; using said test environmental parameters, respectivelyThe load S of the mutual inductor is calculated by the following formula₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein the test environmental parameters include: mutual inductor is respectively in no-load and load S₁Difference of ratio f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁mutual inductor under load S₁And a load S₂Angle of power factor of

And

further, when the selected correction algorithm relates to a temperature correction algorithm, acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, including:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the transformer parameters, respectively adopting the following formulas to calculate and obtain a specific value difference f generated by the mutual inductor at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters comprise: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀(ii) a Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

Further, when the selected correction algorithm relates to a frequency correction algorithm, acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, including: acquiring test environment parameters and transformer parameters of a transformer error calibration test; calculating the ratio difference f generated when the power grid frequency f is obtained by using the test environment parameters and the transformer parameters respectively by adopting the following formulas_fPhase difference of sum_f：

Wherein, the test link parameters comprise: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂An intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂(ii) a Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated in the power grid frequency f from the error calibration data_fPhase difference of sum_fAnd obtaining corrected error calibration data.

In a second aspect, an embodiment of the present invention further provides an apparatus for correcting error calibration data of a transformer, including: the instruction receiving unit is used for receiving a correction instruction for correcting the error calibration data of the mutual inductor; the correction algorithm selection unit is used for acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from a plurality of correction algorithms according to the type of the mutual inductor and a preset corresponding rule; and the correction unit is used for acquiring the test environment parameters and/or the transformer parameters of the transformer error calibration test according to the selected correction algorithm, and processing the parameters according to the selected correction algorithm by using the test environment parameters and/or the transformer parameters to obtain corrected error calibration data.

Further, the correction algorithm comprises: a standard device correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

Further, when the selected correction algorithm relates to an external electric field correction algorithm, the correction unit is further configured to: acquiring test environment parameters and transformer parameters of a transformer error calibration test; using the testing environment parameters and the transformer parameters, and utilizing a pre-established external electric field correction model to simulate and obtain the ratio difference f generated by the external electric field interferent_c(ii) a Obtaining error calibration data of the mutual inductor directly obtained by an error calibration test of the mutual inductor, and deducting a ratio difference f generated by the external electric field interferent from the error calibration data_cObtaining corrected error calibration data; wherein, the experimental environment parameter of mutual-inductor error calibration test includes: whether external electric field interferent and external electricity exist aroundThe distance between the field interferent and the transformer; the mutual sensor parameters include: high-voltage capacitance C of mutual inductor₁Low voltage capacitance C₂And a nominal primary voltage.

Further, the external electric field correction model is previously established as follows: constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters; acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is a ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is a ratio difference generated by the external electric field interferent simulated by the initial model; and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

Further, when the selected correction algorithm relates to a etalon correction algorithm, the correction unit is further configured to: acquiring test environment parameters of a transformer error calibration test and error calibration data of the transformer directly acquired by the error calibration test; deducting the test environment parameters from the error calibration data to obtain corrected error calibration data; wherein the test environment parameter is the self ratio difference f of the current transformer of the standard instrument under the rated current full load_{Sign board}Phase difference of sum_{Sign board}。

Further, when the selected correction algorithm relates to a secondary load correction algorithm, the correction unit is further configured to: acquiring test environment parameters of a mutual inductor error calibration test; using the test environment parameters, respectively adopting the following formulas to calculate and obtain the load S of the mutual inductor₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein the test environmental parameters include: mutual inductor is respectively in no-load and load S₁Difference of ratio f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁mutual inductor under load S₁And a load S₂Angle of power factor of

And

further, when the selected correction algorithm relates to a temperature correction algorithm, the correction unit is further configured to: acquiring test environment parameters and transformer parameters of a transformer error calibration test; using the test environment parameters and the transformer parameters, respectively adopting the following formulas to calculate the ratio difference f generated by the transformer at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters comprise: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀(ii) a Obtained directly from the error calibration test of the transformerError calibration data of the mutual inductor, subtracting the ratio difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

Further, when the selected correction algorithm relates to a frequency correction algorithm, the correction unit is further configured to: acquiring test environment parameters and transformer parameters of a transformer error calibration test; and calculating the ratio difference f generated when the power grid frequency f is obtained by using the test environment parameters and the transformer parameters respectively by adopting the following formulas_fPhase difference of sum_f：

Wherein, the test link parameters comprise: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂An intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂(ii) a Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated in the power grid frequency f from the error calibration data_fPhase difference of sum_fAnd obtaining corrected error calibration data.

According to the method and the device for correcting the error calibration data of the mutual inductor, provided by the embodiment of the invention, on the basis of the original error calibration test data of the mutual inductor, the influence of a test environment on the error calibration data of the mutual inductor is increased, and the reliability and the accuracy of the calibration data are greatly improved; meanwhile, different compensation modes are carried out according to different types of mutual inductors, and the consistency of the test error data and the error data in actual operation is improved. In addition, according to the method and the device for correcting the error calibration data of the mutual inductor provided by the embodiment of the invention, the original error calibration test data of the mutual inductor is corrected, so that the error calibration test operation of the mutual inductor is further standardized, the phenomenon that the error calibration test data is different from person to person is effectively avoided, and the different human error calibration test data in the reference environment can be highly consistent.

Drawings

FIG. 1 illustrates an exemplary flow chart of a method of correcting error calibration data of a transformer according to an embodiment of the present invention;

FIG. 2 shows a schematic diagram of a CVT distributed capacitance in the presence of a metal bracket according to one embodiment of the present invention;

fig. 3 is a diagram showing potential distributions when distances between a metal bracket and a CVT are 2m to 8m, respectively, according to an embodiment of the present invention;

FIG. 4 shows a graph of the effect of a metal bracket on CVT spacing change versus difference value according to one embodiment of the present invention;

fig. 5 is a schematic structural diagram of an apparatus for correcting error calibration data of a transformer according to an embodiment of the present invention.

Detailed Description

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for full and complete disclosure of the invention and to fully convey the scope of the invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

Fig. 1 illustrates an exemplary flow chart of a method of correcting error calibration data of a transformer according to an embodiment of the present invention.

As shown in fig. 1, the method includes:

step S101: and receiving a correction instruction for correcting the error calibration data of the mutual inductor.

In the embodiment of the invention, the correction instruction can be manually input, and when the error calibration tester considers that the test environment is different from the offline environment and needs to be corrected, the correction instruction, the current test environment parameters and the transformer parameters can be input for correction.

Step S102: and obtaining the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from the plurality of correction algorithms according to the type of the mutual inductor and a preset corresponding rule.

In the embodiment of the invention, the preset corresponding rule can be used for carrying out a certain or a plurality of correction algorithms on a certain transformer preset before the correction is started.

Further, the correction algorithm comprises: a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

For example, when the transformer is a current transformer, only the etalon correction algorithm is performed; when the mutual inductor is an electromagnetic voltage mutual inductor, a standard device correction algorithm and a secondary load correction algorithm are carried out; when the transformer is an electromagnetic voltage transformer, a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm are carried out.

In the embodiment, on the basis of original error calibration test data of the mutual inductor, the influence of the external electric field, the standard device, the secondary load, the temperature and the frequency on the error calibration data of the mutual inductor is increased, so that the reliability and the accuracy of the calibration data are greatly improved; meanwhile, different compensation modes are carried out according to different types of mutual inductors, and one or more aspects of an external electric field, a standard device, a secondary load, temperature and frequency are selected to be only corrected, so that the consistency of test error data and error data in actual operation is improved.

Step S103: and acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data.

In the embodiment of the invention, the test environment parameters and the transformer parameters of the transformer error calibration test can comprise parameters related to the test environment and intrinsic parameters of the transformer which are input in advance before the error calibration test starts, and can also comprise parameters related to the test environment which are generated in real time in the error calibration test process. The test environment parameters and/or the transformer parameters are obtained, the test environment parameters and/or the transformer parameters can be obtained respectively according to different correction algorithms, and all parameters of different correction algorithms can be obtained simultaneously at one time. The selected one or more correction algorithms may be performed concurrently with each other. For example, when the mutual inductor is an electromagnetic voltage transformer, a etalon correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm, and an external electric field correction algorithm may be performed at the same time. The corrected error calibration data may be a value or a range. For example, when the grid frequency varies between 49.5Hz and 50.5Hz, the ratio difference of the mutual inductor generated by the grid frequency is 0.056 to-0.055 percent, and the phase difference is 2.6 to-2.5'; the ratio difference of the mutual inductor directly obtained by the mutual inductor error calibration test is 0.110%, the phase difference is 5.66', after the error generated by the power grid frequency is deducted, the corrected ratio difference is 0.054% -0.165%, and the phase difference is 3.06' -8.16 '.

In the embodiment, on the basis of original error calibration test data of the mutual inductor, the influence of test environment factors on the error calibration data of the mutual inductor is increased, and the reliability and the accuracy of the calibration data are greatly improved; meanwhile, different compensation modes are carried out according to different types of mutual inductors, and the consistency of the test error data and the error data in actual operation is improved. In addition, according to the method and the device for correcting the error calibration data of the mutual inductor provided by the embodiment of the invention, the original error calibration test data of the mutual inductor is corrected, so that the error calibration test operation of the mutual inductor is further standardized, the phenomenon that the error calibration test data is different from person to person is effectively avoided, and the different human error calibration test data under the reference environment can be highly consistent.

Further, when the selected correction algorithm relates to an external electric field correction algorithm, step S103 includes:

step S1031: acquiring test environment parameters and transformer parameters of a transformer error calibration test;

step S1032: using the test environment parameters and the mutual inductor parameters, and utilizing a pre-established external electric field correction model to simulate and obtain the ratio difference f generated by the external electric field interferent_c；

Step S1033: obtaining error calibration data of the mutual inductor directly obtained by the mutual inductor error calibration test, and deducting the ratio difference f generated by external electric field interferent from the error calibration data_cObtaining corrected error calibration data;

wherein, mutual-inductor error calibration test's experimental environmental parameter includes: whether an external electric field interference object exists around, and the distance between the external electric field interference object and the mutual inductor; the transformer parameters include: high voltage capacity C of mutual inductor₁Low voltage capacitance C₂And a nominal primary voltage.

In an embodiment of the present invention, the external electric field interference object may be a metal object, such as a metal bracket. The test environment parameters and the transformer parameters of the transformer error calibration test obtained in step S1031 and the error calibration data of the transformer directly obtained by the error calibration test obtained in step S1033 may be obtained in two steps respectively or may be obtained in the same step at the same time.

Further, the external electric field correction model is previously established as follows:

step S001: constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters;

step S002: acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is the ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is the ratio difference generated by the external electric field interferent simulated by an initial model;

step S003: and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

In the embodiment of the invention, when the external electric field interferent is the metal bracket and the mutual inductor is the capacitor voltage mutual inductor (CVT), the primary body of the CVT consists of the capacitive voltage divider and the electromagnetic unit, and the accuracy of the secondary output of the CVT is directly related to the voltage dividing ratio of the capacitive voltage divider in an ideal state. Ideally, the voltage division ratio of the CVT capacitor unit can be expressed as k ═ C1+ C2)/C1, where C1 is the high voltage capacitance of the transformer and C2 is the low voltage capacitance. In a field transformer error test, a CVT is provided with a rated voltage at a primary band, induced potentials exist on a metal support existing around the CVT to form stray capacitance, the CVT generates stray capacitance to the ground and a primary wire, the CVT in operation is in a superposed electric field, and fig. 2 shows a schematic diagram of the distributed capacitance condition of the CVT in the presence of the metal support according to the embodiment of the invention. According to fig. 2, the high voltage capacitor portion of the CVT capacitor unit generates a high voltage distributed capacitance C11' for the primary conductor, a distributed capacitance C12' for the metal bracket, and a distributed capacitance C1' for ground. The low voltage capacitor portion of the CVT capacitor unit generates a distributed capacitance C22 'for the metal support and a distributed capacitance C2' for the CVT capacitor unit. At this time, the voltage division ratio of the capacitor unit can be expressed as:

the capacitance of the low-voltage capacitor C2 of the capacitor unit is large, and the capacitance of C2 is close to the ground potential end, so that the variation of C2 'and C22' is small, and the sizes of C2 'and C22' are considered to be unchanged during the process of increasing the distance between the metal bracket and the CVT. And the capacitance of the high-voltage capacitor C1 is smaller, the capacitance of C12' is obviously reduced along with the increase of the distance between the metal bracket and the CVT, the voltage division ratio k value of the capacitive voltage divider is increased, the intermediate voltage is reduced, and the CVT ratio difference shifts towards the negative direction. An initial model can be established based on the test environment parameters and transformer parameters of the CVT.

In practical tests, according to the principle of the controlled variable method, the distances between the metal bracket and the CVT are controlled to be 2m to 8m respectively while the rest of the distances except the distance between the metal bracket and the CVT are kept unchanged, and the obtained potential distribution when the distance between the CVT and the metal bracket is changed is shown in fig. 3. The influence of the metal bracket and the CVT on the change of the distance between the metal bracket and the CVT is calculated according to the influence of the electric field on the CVT intermediate voltage, and is shown in Table 1.

TABLE 1 ratio difference between metal bracket and CVT at varying spacing

Distance/m	2	3	4	5	6	7	8
								The ratio is poor%	0.05938	0.03124	0.01832	0.01149	0.00763	0.00525	0.00376

From the data shown in table 1, it can be seen that the larger the spacing between the metal bracket and the CVT, the more the CVT ratio difference is shifted in the negative direction. In actual experiments conducted by finite element analysis plotted against the data in table 1, the relationship between the metal bracket and CVT spacing variation versus the difference in effect is shown in fig. 4. According to the verification curve shown in fig. 4, the simulation parameters of the constructed initial model are continuously adjusted to obtain a simulation model finally consistent with the verification curve, and the analysis accuracy of the model is in ten-thousandth.

In the embodiment, the accurate external electric field correction model is obtained by establishing the data model and continuously adjusting the high coincidence between the mathematical model and the actual test data through a large number of tests, and the error generated by the external electric field interferent can be accurately corrected.

Further, when the selected correction algorithm relates to the etalon correction algorithm, step S103 includes:

acquiring test environment parameters of a mutual inductor error calibration test and error calibration data of the mutual inductor directly obtained by the error calibration test;

deducting the test environment parameters from the error calibration data to obtain corrected error calibration data;

wherein the test environment parameter is the self specific value difference f of the current transformer of the standard instrument under the rated current and full load_{Sign board}Phase difference of sum_{Sign board}。

In the embodiment of the invention, only the error of the standard used in the error experiment of the mutual inductor needs to be corrected, and different standards can be used in different error calibration experiments.

For example, when the transformer for error detection is a current transformer, it is possible to selectAnd (3) a standard instrument correction algorithm, if the detected current transformer is 0.2 grade and the standard current transformer is 0.05 grade, carrying out an instrument transformer error test according to a test wiring mode recommended in a verification procedure of JJG 1021 plus 2007 Power Transformer, wherein an instrument transformer calibrator displays that the ratio difference f of the detected current transformer under the rated current full load is 0.110 percent and the phase difference is 5.66', and the ratio difference f of the standard instrument current transformer under the rated current full load is self_{Sign board}0.022% phase difference_{Sign board}1.04', the error of the detected current transformer is obtained by subtracting the additional error introduced by the standard device:

the difference f' (%) f-f_{Sign board}＝0.110％-0.022％＝0.088％；

Phase difference '(') -_{Sign board}＝5.66'-1.04'＝4.62'。

Further, when the selected correction algorithm relates to a secondary load correction algorithm, step S103 includes:

acquiring test environment parameters of a mutual inductor error calibration test;

using the test environment parameters, respectively adopting the following formula to calculate and obtain the load S of the mutual inductor₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein, the test environmental parameters include: mutual inductor is respectively in no-load and load S₁Ratio difference f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁the mutual inductor is respectively under the load S₁And a load S₂Angle of power factor of

And

in the embodiment of the invention, the transformer needs to be subjected to rated load S₁And carrying out an error calibration test under the condition of no load to obtain corresponding test environment parameters.

For example, when the error calibration data of one 220kV voltage class voltage transformer is corrected, the correction is performed when the secondary load correction algorithm is selected. The voltage transformer to be tested is of a double-winding structure, one metering winding and one protection/measurement winding, the power factor is 0.8, and f is the voltage transformer with the rated voltage under the condition that the two windings are in no-load₀＝-0.025％，₀0.90'; metering 75VA of winding, protection/measurement 150VA of winding, f₁＝-0.194％，₁9.46'; when the measurement shows that the metering winding load is 2.5VA and the protection/measurement winding load is 150VA when the voltage transformer is actually tested and operated, the ratio difference f of the voltage transformer is calculated when the secondary load is actually tested₂Phase difference of sum₂Comprises the following steps:

further, when the selected correction algorithm relates to a temperature correction algorithm, step S103 includes:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

the method comprises the steps of using test environment parameters and transformer parameters, and respectively calculating by the following formulas to obtain a specific value difference f generated by the transformer at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters include: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀；

Acquiring error calibration data of the mutual inductor directly obtained by the mutual inductor error calibration test, and deducting the specific value difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

In the embodiment of the invention, the mutual inductor can be a capacitor voltage mutual inductor, and the high-voltage capacitor C of the capacitor voltage mutual inductor is caused by temperature change₁And a low-voltage capacitor C₂The capacitance of the capacitor voltage transformer is changed, and the residual reactance in the capacitor voltage transformer is changed, so that the error is caused by the residual reactance. The reference temperature may be a temperature that is manually preset.

Further, when the selected correction algorithm relates to a frequency correction algorithm, step S103 includes:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

the method comprises the steps of using test environment parameters and mutual inductor parameters, and respectively calculating by adopting the following formulas to obtain a specific value difference f generated when the power grid frequency f is measured_fPhase difference of sum_f：

Wherein, the test link parameters include: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the mutual inductor parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated when the error calibration data is at the power grid frequency f_fPhase difference of sum_fAnd obtaining corrected error calibration data.

In the embodiment of the invention, the transformer can be a capacitor voltage transformer, and the secondary output of the capacitor voltage transformer is determined to be capacitive equipment influenced by frequency by the structural principle of the capacitor voltage transformer. When the capacitor voltage transformer is designed, the residual reactance of the capacitor voltage transformer under 50Hz is generally approximate to zero, and the requirement of the capacitor voltage transformer on the residual reactance is met

The residual reactance is capacitance and compensation reactor inductance L_cSecondary side leakage inductance L of electromagnetic unit_T1、L_T2The reactance value after series connection at a specific angular frequency ω ═ 2 π f is denoted as X₀. Resulting in a residual reactance X inside the CVT when a frequency change occurs₀A shift occurs. When the error detection of the field mutual inductor is carried out, the used test power supply is provided by a test transformer, the power supply quality is stable, the power supply in actual operation is a primary power supply of a power grid, and the power supply is influenced by factors such as primary equipment of the power grid, the size and the type of a user load, so that the frequency of the power supply fluctuates. Therefore, when the field transformer error detection is carried out, the frequency correction needs to be carried out on the error data for the capacitor voltage transformer.

Example 1

In one embodiment, the manual input pre-configured rule is: if the current transformer is adopted, a standard device correction algorithm is carried out; if the voltage transformer is an electromagnetic voltage transformer, a standard device correction algorithm and a secondary load correction algorithm are carried out; and if the capacitance voltage mutual inductance is detected, performing a standard device correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

The mutual inductor to be detected in the error calibration test is a capacitor voltage mutual inductor with the voltage class of 220 kV. Ratio difference f of standard device current transformer used in test under rated current full load_{Sign board}Phase difference of sum_{Sign board}0.022% and 1.04' respectively; the tested capacitor voltage transformer has a double-winding structure, a metering winding and a protection/measurement winding, the power factor is 0.8, and under the condition that both windings are in no-load under rated voltage, f is₀＝-0.025％，₀0.90', the metering winding load is 75VA, and when the protection/measurement winding load is 150VA, f₁＝-0.194％，₁When measured, the metering winding load of the capacitor voltage transformer is 2.5VA during practical test operation, and the protection/measurement winding load is 150 VA; at 50Hz, C₁＝8355pF，C₂＝73280pF，U_CN13kV, total load S200 VA, power factor 0.8, and temp coefficient of capacitance-0.0002K^-1The temperature in the actual test is 30 ℃ by taking 20 ℃ as a reference value; in an actual test, the frequency of a power grid in operation can change between 49.5Hz and 50.5Hz, the rated frequency of the power grid is 50Hz, the active power coefficient is 0.8, and the reactive power coefficient is 0.6; and a metal bracket is arranged at a distance of 3 meters from the capacitor voltage transformer.

The method for correcting the error calibration data of the transformer provided by the embodiment includes:

step S201: receiving a correction instruction for correcting error calibration data of the mutual inductor;

step S202: acquiring a transformer type of a capacitor voltage transformer, and performing a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm according to a preset corresponding rule;

step S203: for the correcting algorithm of the standard device, the self ratio difference f of the current transformer of the standard device under the rated current full load is obtained_{Sign board}Phase difference of sum_{Sign board}0.022% and 1.04' respectively;

for the secondary load correction algorithm, according to the power factor

Under the condition that both windings are in no-load under rated voltage, f₀＝-0.025％，₀0.90', the metering winding load is 75VA, and when the protection/measurement winding load is 150VA, f₁＝-0.194％，₁When the measured voltage transformer is measured, the measured winding load is 2.5VA and the protection/measurement winding load is 150VA during actual test operation, and the ratio difference f of the voltage transformer during actual test secondary load is calculated by adopting the following formula₂Phase difference of sum₂Comprises the following steps:

for the temperature correction algorithm, according to f-50 Hz, C₁＝8355pF，C₂＝73280pF，U_CN13kV total load S200 VA, power factor

Temperature coefficient of capacitance alpha is-0.0002K^-1Taking 20 ℃ as a reference value and the temperature of 30 ℃ in an actual test, and respectively calculating by adopting the following formula to obtain the specific value difference f generated when the temperature of the mutual inductor is 30 DEG C_tPhase difference of sum_t：

For frequencyRate correction algorithm according to C₁＝8355pF，C₂＝73280pF，U_CN13kV, total load S200 VA, rated frequency of the power grid is 50Hz, active power coefficient is 0.8, reactive power coefficient is 0.6, the frequency of the power grid in operation varies between 49.5Hz and 50.5Hz in an actual test, and a ratio difference f generated when the frequency of the power grid is 50Hz is calculated by adopting the following formula_fPhase difference of sum_f：

Meanwhile, the ratio difference f generated at the grid frequency of 49.5Hz is calculated by the following formula_fAnd phase difference_f：

Obtaining a ratio difference f generated when the frequency varies between 49.5Hz and 50.5Hz in the operation of the power grid_fPhase difference of_fThe range of (A) is 0.056 to-0.055%, 2.6 to-2.5';

for the external electric field correction algorithm, a metal bracket is arranged at a position 3 meters away from the capacitor voltage transformer, C₁＝8355pF，C₂73280pF, using the external electric field correction model established in advance, the difference f of the ratio value produced by the metal support is obtained through simulation_c0.0027%;

the ratio difference f of the voltage transformer during secondary load is obtained according to the calculation₂Phase difference of sum₂And deducting errors generated by the standard device, the temperature, the frequency and the external electric field, and finally obtaining corrected error calibration data:

difference of ratio

f_{Reference to}(％)＝f₂-f_{Sign board}-f_t-f_f-f_c

＝-0.031-0.022-(-0.0055)-(0.056～-0.055)-00027＝0.0062％～0.0173％；

Phase difference

_{Reference to}(′)＝₂-_{Sign board}-_t-_f＝0.615-1.04-0.25-(2.6～-2.5)＝-3.275′～1.825′。

Fig. 5 is a schematic structural diagram of an apparatus for correcting error calibration data of a transformer according to an embodiment of the present invention.

As shown in fig. 5, the apparatus includes:

the instruction receiving unit 501 is configured to receive a correction instruction for correcting error calibration data of the transformer.

In the embodiment of the invention, the correction instruction can be manually input, and when the error calibration tester considers that the test environment is different from the offline environment and needs to be corrected, the correction instruction, the current test environment parameters and the transformer parameters can be input for correction.

And the correction algorithm selection unit 502 is used for acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from the plurality of correction algorithms according to the type of the mutual inductor and a preset corresponding rule.

In the embodiment of the invention, the preset corresponding rule can be used for carrying out a certain or a plurality of correction algorithms on a certain transformer preset before the correction is started.

Further, the correction algorithm comprises: a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

For example, when the transformer is a current transformer, only the etalon correction algorithm is performed; when the mutual inductor is an electromagnetic voltage mutual inductor, a standard device correction algorithm and a secondary load correction algorithm are carried out; when the transformer is an electromagnetic voltage transformer, a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm are carried out.

In the embodiment, on the basis of original error calibration test data of the mutual inductor, the influence of the external electric field, the standard device, the secondary load, the temperature and the frequency on the error calibration data of the mutual inductor is increased, so that the reliability and the accuracy of the calibration data are greatly improved; meanwhile, different compensation modes are carried out according to different types of mutual inductors, and one or more aspects of an external electric field, a standard device, a secondary load, temperature and frequency are selected to be only corrected, so that the consistency of test error data and error data in actual operation is improved.

And a correcting unit 503, configured to obtain a test environment parameter and/or a transformer parameter of the transformer error calibration test according to the selected correction algorithm, and perform processing according to the selected correction algorithm by using the test environment parameter and/or the transformer parameter, so as to obtain corrected error calibration data.

In the embodiment of the invention, the test environment parameters and the transformer parameters of the transformer error calibration test can comprise parameters related to the test environment and intrinsic parameters of the transformer which are input in advance before the error calibration test starts, and can also comprise parameters related to the test environment which are generated in real time in the error calibration test process. The test environment parameters and/or the transformer parameters are obtained, the test environment parameters and/or the transformer parameters can be obtained respectively according to different correction algorithms, and all parameters of different correction algorithms can be obtained simultaneously at one time. The selected one or more correction algorithms may be performed concurrently with each other. For example, when the mutual inductor is an electromagnetic voltage transformer, a etalon correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm, and an external electric field correction algorithm may be performed at the same time. The corrected error calibration data may be a value or a range. For example, when the grid frequency varies between 49.5Hz and 50.5Hz, the ratio difference of the mutual inductor generated by the grid frequency is 0.056 to-0.055 percent, and the phase difference is 2.6 to-2.5'; the ratio difference of the mutual inductor directly obtained by the mutual inductor error calibration test is 0.110%, the phase difference is 5.66', after the error generated by the power grid frequency is deducted, the corrected ratio difference is 0.054% -0.165%, and the phase difference is 3.06' -8.16 '.

In the embodiment, on the basis of original error calibration test data of the mutual inductor, the influence of test environment factors on the error calibration data of the mutual inductor is increased, and the reliability and the accuracy of the calibration data are greatly improved; meanwhile, different compensation modes are carried out according to different types of mutual inductors, and the consistency of the test error data and the error data in actual operation is improved. In addition, according to the method and the device for correcting the error calibration data of the mutual inductor provided by the embodiment of the invention, the original error calibration test data of the mutual inductor is corrected, so that the error calibration test operation of the mutual inductor is further standardized, the phenomenon that the error calibration test data is different from person to person is effectively avoided, and the different human error calibration test data under the reference environment can be highly consistent.

Further, when the selected correction algorithm relates to an external electric field correction algorithm, the correction unit 503 is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the mutual inductor parameters, and utilizing a pre-established external electric field correction model to simulate and obtain the ratio difference f generated by external electric field interferents_c；

Obtaining error calibration data of the mutual inductor directly obtained by the mutual inductor error calibration test, and deducting the ratio difference f generated by external electric field interferent from the error calibration data_cObtaining corrected error calibration data;

wherein, mutual-inductor error calibration test's experimental environmental parameter includes: whether an external electric field interference object exists around, and the distance between the external electric field interference object and the mutual inductor; the transformer parameters include: high voltage capacity C of mutual inductor₁Low voltage capacitance C₂And a nominal primary voltage.

In an embodiment of the present invention, the external electric field interference object may be a metal object, such as a metal bracket. The method comprises the steps of obtaining test environment parameters and transformer parameters of a mutual inductor error calibration test, and obtaining error calibration data of the mutual inductor directly obtained by the error calibration test, wherein the test environment parameters and the transformer parameters can be obtained in two steps respectively, or can be obtained simultaneously in the same step.

Further, the external electric field correction model is previously established as follows:

constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters;

acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is the ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is the ratio difference generated by the external electric field interferent simulated by an initial model;

and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

In the embodiment of the invention, when the external electric field interferent is the metal bracket and the mutual inductor is the capacitor voltage mutual inductor (CVT), the primary body of the CVT consists of the capacitive voltage divider and the electromagnetic unit, and the accuracy of the secondary output of the CVT is directly related to the voltage dividing ratio of the capacitive voltage divider in an ideal state. Ideally, the voltage division ratio of the CVT capacitor unit can be expressed as k ═ C1+ C2)/C1, where C1 is the high voltage capacitance of the transformer and C2 is the low voltage capacitance. In a field transformer error test, a CVT is provided with a rated voltage at a primary band, induced potentials exist on a metal support existing around the CVT to form stray capacitance, the CVT generates stray capacitance to the ground and a primary wire, the CVT in operation is in a superposed electric field, and fig. 2 shows a schematic diagram of the distributed capacitance condition of the CVT in the presence of the metal support according to the embodiment of the invention. According to fig. 2, the high voltage capacitor portion of the CVT capacitor unit generates a high voltage distributed capacitance C11' for the primary conductor, a distributed capacitance C12' for the metal bracket, and a distributed capacitance C1' for ground. The low voltage capacitor portion of the CVT capacitor unit generates a distributed capacitance C22 'for the metal support and a distributed capacitance C2' for the CVT capacitor unit. At this time, the voltage division ratio of the capacitor unit can be expressed as:

the capacitance of the low-voltage capacitor C2 of the capacitor unit is large, and the capacitance of C2 is close to the ground potential end, so that the variation of C2 'and C22' is small, and the sizes of C2 'and C22' are considered to be unchanged during the process of increasing the distance between the metal bracket and the CVT. And the capacitance of the high-voltage capacitor C1 is smaller, the capacitance of C12' is obviously reduced along with the increase of the distance between the metal bracket and the CVT, the voltage division ratio k value of the capacitive voltage divider is increased, the intermediate voltage is reduced, and the CVT ratio difference shifts towards the negative direction. An initial model can be established based on the test environment parameters and transformer parameters of the CVT.

In practical tests, according to the principle of the controlled variable method, the distances between the metal bracket and the CVT are controlled to be 2m to 8m respectively while the rest of the distances except the distance between the metal bracket and the CVT are kept unchanged, and the obtained potential distribution when the distance between the CVT and the metal bracket is changed is shown in fig. 3. The influence of the metal bracket and the CVT on the change of the distance between the metal bracket and the CVT is calculated according to the influence of the electric field on the CVT intermediate voltage, and is shown in Table 1.

TABLE 1 ratio difference between metal bracket and CVT at varying spacing

Distance/m	2	3	4	5	6	7	8
								The ratio is poor%	0.05938	0.03124	0.01832	0.01149	0.00763	0.00525	0.00376

From the data shown in table 1, it can be seen that the larger the spacing between the metal bracket and the CVT, the more the CVT ratio difference is shifted in the negative direction. In actual experiments conducted by finite element analysis plotted against the data in table 1, the relationship between the metal bracket and CVT spacing variation versus the difference in effect is shown in fig. 4. According to the verification curve shown in fig. 4, the simulation parameters of the constructed initial model are continuously adjusted to obtain a simulation model finally consistent with the verification curve, and the analysis accuracy of the model is in ten-thousandth.

In the embodiment, the accurate external electric field correction model is obtained by establishing the data model and continuously adjusting the high coincidence between the mathematical model and the actual test data through a large number of tests, and the error generated by the external electric field interferent can be accurately corrected.

Further, when the selected correction algorithm relates to a etalon correction algorithm, the correction unit 301 is further configured to:

acquiring test environment parameters of a mutual inductor error calibration test and error calibration data of the mutual inductor directly obtained by the error calibration test;

deducting the test environment parameters from the error calibration data to obtain corrected error calibration data;

wherein, the test environmental parameters are targetsRatio difference f of calibrator current transformer under rated current full load_{Sign board}Phase difference of sum_{Sign board}。

In the embodiment of the invention, only the error of the standard used in the error experiment of the mutual inductor needs to be corrected, and different standards can be used in different error calibration experiments.

For example, when the current transformer for error detection is a current transformer, a standard device correction algorithm may be selected, if the current transformer to be detected is of 0.2 level and the standard current transformer is of 0.05 level, a transformer error test is performed according to a test wiring mode recommended in the verification procedure of JJG 1021-_{Sign board}0.022% phase difference_{Sign board}1.04', the error of the detected current transformer is obtained by subtracting the additional error introduced by the standard device:

the difference f' (%) f-f_{Sign board}＝0.110％-0.022％＝0.088％；

Phase difference '(') -_{Sign board}＝5.66'-1.04'＝4.62'。

Further, when the selected correction algorithm relates to a secondary load correction algorithm, the correction unit 301 is further configured to:

acquiring test environment parameters of a mutual inductor error calibration test;

using the test environment parameters, respectively adopting the following formula to calculate and obtain the load S of the mutual inductor₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein the test environmentThe parameters include: mutual inductor is respectively in no-load and load S₁Ratio difference f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁the mutual inductor is respectively under the load S₁And a load S₂Angle of power factor of

And

in the embodiment of the invention, the transformer needs to be subjected to rated load S₁And carrying out an error calibration test under the condition of no load to obtain corresponding test environment parameters.

For example, when the error calibration data of one 220kV voltage class voltage transformer is corrected, the correction is performed when the secondary load correction algorithm is selected. The voltage transformer to be tested is of a double-winding structure, one metering winding and one protection/measurement winding, the power factor is 0.8, and f is the voltage transformer with the rated voltage under the condition that the two windings are in no-load₀＝-0.025％，₀0.90'; metering 75VA of winding, protection/measurement 150VA of winding, f₁＝-0.194％，₁9.46'; when the measurement shows that the metering winding load is 2.5VA and the protection/measurement winding load is 150VA when the voltage transformer is actually tested and operated, the ratio difference f of the voltage transformer is calculated when the secondary load is actually tested₂Phase difference of sum₂Comprises the following steps:

further, when the selected correction algorithm relates to a temperature correction algorithm, the correction unit 301 is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

the method comprises the steps of using test environment parameters and transformer parameters, and respectively calculating by the following formulas to obtain a specific value difference f generated by the transformer at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters include: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀；

Acquiring error calibration data of the mutual inductor directly obtained by the mutual inductor error calibration test, and deducting the specific value difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

In the embodiment of the invention, the mutual inductor can be a capacitor voltage mutual inductor, and the high-voltage capacitor C of the capacitor voltage mutual inductor is caused by temperature change₁And a low-voltage capacitor C₂The capacitance of the capacitor voltage transformer is changed, and the residual reactance in the capacitor voltage transformer is changed, so that the error is caused by the residual reactance. The reference temperature may be a temperature that is manually preset.

Further, when the selected correction algorithm relates to a frequency correction algorithm, the correction unit 301 is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the mutual inductor parameters respectively as followsCalculating a ratio difference f generated in the power grid frequency f by a formula_fPhase difference of sum_f：

Wherein, the test link parameters include: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the mutual inductor parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated when the error calibration data is at the power grid frequency f_fPhase difference of sum_fAnd obtaining corrected error calibration data.

In the embodiment of the invention, the transformer can be a capacitor voltage transformer, and the secondary output of the capacitor voltage transformer is determined to be capacitive equipment influenced by frequency by the structural principle of the capacitor voltage transformer. When the capacitor voltage transformer is designed, the residual reactance of the capacitor voltage transformer under 50Hz is generally approximate to zero, and the requirement of the capacitor voltage transformer on the residual reactance is met

The residual reactance is capacitance and compensation reactor inductance L_cSecondary side leakage inductance L of electromagnetic unit_T1、L_T2The reactance value after series connection at a specific angular frequency ω ═ 2 π f is denoted as X₀. Resulting in a residual reactance X inside the CVT when a frequency change occurs₀A shift occurs. When the error detection of the field mutual inductor is carried out, the used test power supply is provided by a test transformer, the power supply quality is stable, the power supply in actual operation is a power grid primary power supply, and the power supply is influenced by factors such as power grid primary equipment and user load size and type, so that the frequency of the power supply fluctuates.Therefore, when the field transformer error detection is carried out, the frequency correction needs to be carried out on the error data for the capacitor voltage transformer.

Example 2

In one embodiment, the manual input pre-configured rule is: if the current transformer is adopted, a standard device correction algorithm is carried out; if the voltage transformer is an electromagnetic voltage transformer, a standard device correction algorithm and a secondary load correction algorithm are carried out; and if the capacitance voltage mutual inductance is detected, performing a standard device correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

The mutual inductor to be detected in the error calibration test is a capacitor voltage mutual inductor with the voltage class of 220 kV. Ratio difference f of standard device current transformer used in test under rated current full load_{Sign board}Phase difference of sum_{Sign board}0.022% and 1.04' respectively; the tested capacitor voltage transformer has a double-winding structure, a metering winding and a protection/measurement winding, the power factor is 0.8, and under the condition that both windings are in no-load under rated voltage, f is₀＝-0.025％，₀0.90', the metering winding load is 75VA, and when the protection/measurement winding load is 150VA, f₁＝-0.194％，₁When measured, the metering winding load of the capacitor voltage transformer is 2.5VA during practical test operation, and the protection/measurement winding load is 150 VA; at 50Hz, C₁＝8355pF，C₂＝73280pF，U_CN13kV, total load S200 VA, power factor 0.8, and temp coefficient of capacitance-0.0002K^-1The temperature in the actual test is 30 ℃ by taking 20 ℃ as a reference value; in an actual test, the frequency of a power grid in operation can change between 49.5Hz and 50.5Hz, the rated frequency of the power grid is 50Hz, the active power coefficient is 0.8, and the reactive power coefficient is 0.6; and a metal bracket is arranged at a distance of 3 meters from the capacitor voltage transformer.

The apparatus for correcting error calibration data of the transformer provided in this embodiment includes:

an instruction receiving unit 601, configured to receive a correction instruction for correcting error calibration data of a transformer;

a correction algorithm selection unit 602, configured to obtain that the transformer type is a capacitive voltage transformer, and perform a etalon correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm, and an external electric field correction algorithm according to a pre-configured correspondence rule;

a correcting unit 603, configured to obtain, for the etalon correcting algorithm, a ratio difference f of the etalon current transformer under a rated current full load_{Sign board}Phase difference of sum_{Sign board}0.022% and 1.04' respectively;

for the secondary load correction algorithm, according to the power factor

Under the condition that both windings are in no-load under rated voltage, f₀＝-0.025％，₀0.90', the metering winding load is 75VA, and when the protection/measurement winding load is 150VA, f₁＝-0.194％，₁When the measured voltage transformer is measured, the measured winding load is 2.5VA and the protection/measurement winding load is 150VA during actual test operation, and the ratio difference f of the voltage transformer during actual test secondary load is calculated by adopting the following formula₂Phase difference of sum₂Comprises the following steps:

for the temperature correction algorithm, according to f-50 Hz, C₁＝8355pF，C₂＝73280pF，U_CN13kV total load S200 VA, power factor

Temperature coefficient of capacitance alpha is-0.0002K^-1The reference value is 20 ℃, the temperature in the actual test is 30 ℃, and the reference value and the temperature are respectively adoptedThe specific value difference f generated by the mutual inductor at the temperature of 30 ℃ is calculated by the following formula_tPhase difference of sum_t：

For the frequency correction algorithm, according to C₁＝8355pF，C₂＝73280pF，U_CN13kV, total load S200 VA, rated frequency of the power grid is 50Hz, active power coefficient is 0.8, reactive power coefficient is 0.6, the frequency of the power grid in operation varies between 49.5Hz and 50.5Hz in an actual test, and a ratio difference f generated when the frequency of the power grid is 50Hz is calculated by adopting the following formula_fPhase difference of sum_f：

Meanwhile, the ratio difference f generated at the grid frequency of 49.5Hz is calculated by the following formula_fAnd phase difference_f：

Obtaining a ratio difference f generated when the frequency varies between 49.5Hz and 50.5Hz in the operation of the power grid_fPhase difference of_fThe range of (A) is 0.056 to-0.055%, 2.6 to-2.5';

for the external electric field correction algorithm, the capacitance voltage transformer exists at a position of 3 metersA metal holder, C₁＝8355pF，C₂73280pF, using the external electric field correction model established in advance, the difference f of the ratio value produced by the metal support is obtained through simulation_c0.0027%;

the ratio difference f of the voltage transformer during secondary load is obtained according to the calculation₂Phase difference of sum₂And deducting errors generated by the standard device, the temperature, the frequency and the external electric field, and finally obtaining corrected error calibration data:

difference of ratio

f_{Reference to}(％)＝f₂-f_{Sign board}-f_t-f_f-f_c

＝-0.031-0.022-(-0.0055)-(0.056～-0.055)-00027＝0.0062％～0.0173％；

Phase difference

_{Reference to}(′)＝₂-_{Sign board}-_t--_f＝0.615-1.04-0.25-(2.6～-2.5)＝-3.275′～1.825′。

The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Claims (16)

1. A method of correcting error calibration data for a transformer, the method comprising:

receiving a correction instruction for correcting error calibration data of the mutual inductor;

acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from a plurality of correction algorithms according to a preset corresponding rule according to the type of the mutual inductor;

and acquiring test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm by using the test environment parameters and/or transformer parameters to obtain corrected error calibration data.

2. The method of claim 1, wherein the correction algorithm comprises: a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

3. The method of claim 2, wherein when the selected correction algorithm relates to an external electric field correction algorithm, obtaining test environment parameters and/or transformer parameters of a transformer error calibration test according to the selected correction algorithm, and processing according to the selected correction algorithm using the test environment parameters and/or transformer parameters to obtain corrected error calibration data, comprising:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the transformer parameters, and using a pre-established external electric field correction model to simulate and obtain a ratio difference f generated by an external electric field interference object_c；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting a ratio difference f generated by the external electric field interferent from the error calibration data_cObtaining corrected error calibration data;

wherein, experimental environmental parameters of mutual-inductor error calibration test include: whether an external electric field interference object exists around, and the distance between the external electric field interference object and the mutual inductor; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low voltage capacitance C₂And a nominal primary voltage.

4. The method according to claim 3, wherein the external electric field correction model is pre-established as follows:

constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters;

acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is a ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is a ratio difference generated by the external electric field interferent simulated by the initial model;

and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

5. The method according to any one of claims 1 to 4, wherein when the selected correction algorithm relates to a etalon correction algorithm, the obtaining of the test environment parameters and/or the transformer parameters of the transformer error calibration test according to the selected correction algorithm and the processing according to the selected correction algorithm using the test environment parameters and/or the transformer parameters to obtain corrected error calibration data comprises:

acquiring test environment parameters of a transformer error calibration test and error calibration data of the transformer directly acquired by the error calibration test;

deducting the test environment parameters from the error calibration data to obtain corrected error calibration data;

wherein the test environment parameter is the ratio difference f of the current transformer of the standard instrument under the rated current and full load_{Sign board}Phase difference of sum_{Sign board}。

6. The method according to any one of claims 1 to 4, wherein when the selected correction algorithm relates to a secondary load correction algorithm, the obtaining of the test environment parameters and/or the transformer parameters of the transformer error calibration test according to the selected correction algorithm and the processing according to the selected correction algorithm using the test environment parameters and/or the transformer parameters to obtain corrected error calibration data comprises:

acquiring test environment parameters of a mutual inductor error calibration test;

using the test environment parameters, respectively adopting the following formulas to calculate and obtain the load S of the mutual inductor₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein the test environmental parameters include: mutual inductor is respectively in no-load and load S₁Ratio difference f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁mutual inductor under load S₁And a load S₂Angle of power factor of

And

7. the method according to any one of claims 1 to 4, wherein when the selected correction algorithm relates to a temperature correction algorithm, the obtaining a test environment parameter and/or a transformer parameter of a transformer error calibration test according to the selected correction algorithm, and using the test environment parameter and/or the transformer parameter to perform processing according to the selected correction algorithm to obtain corrected error calibration data comprises:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the transformer parameters, respectively adopting the following formulas to calculate and obtain a specific value difference f generated by the transformer at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters comprise: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the specific value difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

8. The method according to any one of claims 1 to 4, wherein when the selected correction algorithm relates to a frequency correction algorithm, the obtaining a test environment parameter and/or a transformer parameter of a transformer error calibration test according to the selected correction algorithm, and using the test environment parameter and/or the transformer parameter to perform processing according to the selected correction algorithm to obtain corrected error calibration data comprises:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

and calculating the ratio difference f generated when the power grid frequency f is obtained by using the test environment parameters and the transformer parameters respectively by adopting the following formulas_fPhase difference of sum_f：

Wherein, the test link parameters comprise: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated in the power grid frequency f from the error calibration data_fPhase difference of sum_fAnd obtaining corrected error calibration data.

9. An apparatus for correcting error calibration data of a transformer, the apparatus comprising:

the instruction receiving unit is used for receiving a correction instruction for correcting the error calibration data of the mutual inductor;

the correction algorithm selection unit is used for acquiring the type of the mutual inductor according to the correction instruction, and selecting at least one correction algorithm from a plurality of correction algorithms according to the type of the mutual inductor and a preset corresponding rule;

and the correcting unit is used for acquiring the test environment parameters and/or the transformer parameters of the transformer error calibration test according to the selected correction algorithm, and processing the test environment parameters and/or the transformer parameters according to the selected correction algorithm to obtain corrected error calibration data.

10. The apparatus of claim 9, wherein the correction algorithm comprises: a standard correction algorithm, a secondary load correction algorithm, a temperature correction algorithm, a frequency correction algorithm and an external electric field correction algorithm.

11. The apparatus of claim 10, wherein when the selected correction algorithm relates to an external electric field correction algorithm, the correction unit is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the transformer parameters, and using a pre-established external electric field correction model to simulate and obtain a ratio difference f generated by an external electric field interference object_c；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting a ratio difference f generated by the external electric field interferent from the error calibration data_cObtaining corrected error calibration data;

wherein, experimental environmental parameters of mutual-inductor error calibration test include: whether an external electric field interference object exists around, and the distance between the external electric field interference object and the mutual inductor; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low voltage capacitance C₂And a nominal primary voltage.

12. The apparatus of claim 11, wherein the external electric field correction model is pre-established as follows:

constructing an initial model based on test environment parameters of a transformer error calibration test and transformer parameters;

acquiring an actual external electric field ratio difference and a simulated external electric field ratio difference between the external electric field interferent and the mutual inductor at different distances, wherein the actual external electric field ratio difference is a ratio difference generated by the external electric field interferent calculated in an actual test, and the simulated external electric field ratio difference is a ratio difference generated by the external electric field interferent simulated by the initial model;

and comparing the actual external electric field ratio difference with the simulated external electric field ratio difference, and adjusting the simulation parameters of the initial model until the simulated external electric field ratio difference is consistent with the actual external electric field ratio difference.

13. The apparatus according to any of claims 9-12, wherein when the selected correction algorithm relates to a normalizer correction algorithm, the correction unit is further configured to:

acquiring test environment parameters of a transformer error calibration test and error calibration data of the transformer directly acquired by the error calibration test;

deducting the test environment parameters from the error calibration data to obtain corrected error calibration data;

wherein the test environment parameter is the ratio difference f of the current transformer of the standard instrument under the rated current and full load_{Sign board}Phase difference of sum_{Sign board}。

14. The arrangement according to any of claims 9-12, wherein when the selected correction algorithm relates to a secondary load correction algorithm, the correction unit is further configured to:

acquiring test environment parameters of a mutual inductor error calibration test;

using the test environment parameters, respectively adopting the following formulas to calculate and obtain the load S of the mutual inductor₂The error calibration data after the next secondary load correction are respectively the ratio difference f₂Phase difference of sum₂：

Wherein the test environmental parameters include: mutual inductor is respectively in no-load and load S₁Ratio difference f₀And f₁The mutual inductor is respectively in the load no-load state and the load state₁Phase difference of₀And₁mutual inductor under load S₁And a load S₂Angle of power factor of

And

15. the apparatus according to any of claims 9-12, wherein when the selected correction algorithm relates to a temperature correction algorithm, the correction unit is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

using the test environment parameters and the transformer parameters, respectively adopting the following formulas to calculate and obtain a specific value difference f generated by the transformer at the temperature T_tPhase difference of sum_t：

Wherein, the test link parameters comprise: temperature T, reference temperature T₀Voltage frequency f; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Temperature coefficient alpha of capacitance of mutual inductor, rated total load S of mutual inductor and intermediate voltage U_CNAngle of load power factor

Relative temperature Δ T ═ T-T₀；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the specific value difference f generated at the temperature T from the error calibration data_tPhase difference of sum_tAnd obtaining corrected error calibration data.

16. The apparatus according to any of claims 9-12, wherein when the selected correction algorithm relates to a frequency correction algorithm, the correction unit is further configured to:

acquiring test environment parameters and transformer parameters of a transformer error calibration test;

and calculating the ratio difference f generated when the power grid frequency f is obtained by using the test environment parameters and the transformer parameters respectively by adopting the following formulas_fPhase difference of sum_f：

Wherein, the test link parameters comprise: rated angular frequency omega of power grid_nActual angular frequency omega of the power grid; the transformer parameters include: high-voltage capacitance C of mutual inductor₁Low-voltage capacitance C of mutual inductor₂Intermediate voltage U_CNActive power P and reactive power Q; equivalent capacitance C ═ C₁+C₂；

Acquiring error calibration data of the mutual inductor directly obtained by a mutual inductor error calibration test, and deducting the ratio difference f generated in the power grid frequency f from the error calibration data_fPhase difference of sum_fAnd obtaining corrected error calibration data.

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