High-accuracy voltage ratio standard device and implementation method therefor

Abstract

The present invention relates to a high-accuracy voltage ratio standard device and an implementation method therefor. The voltage ratio standard device comprises an electromagnetic potential transformer, a ratio difference compensation module coupled to the electromagnetic potential transformer, and an angle difference compensation module connected to the electromagnetic potential transformer and the ratio difference compensation module, wherein the ratio difference compensation module comprises a compensation potential transformer coupled to the electromagnetic potential transformer, a first auxiliary potential transformer connected to the compensation potential transformer, and a first precision adjustable resistor connected in parallel to the first auxiliary potential transformer; the angle difference compensation module comprises a quadrature voltage acquisition unit connected to a primary winding of the electromagnetic potential transformer, and a second precision adjustable resistor connected to the quadrature voltage acquisition unit and connected to a secondary winding of the first auxiliary potential transformer; and the ratio difference compensation module is configured to perform compensation of a predetermined ratio difference compensation amount on the ratio difference of the voltage ratio standard device; and the angle difference compensation module is configured to perform compensation of a predetermined angle difference compensation amount on the angle difference of the voltage ratio standard device.

Description

High-accuracy voltage ratio standard and implementation method TECHNICAL FIELD

[0001] The present application relates to the technical field of power measurement standards. In particular, it relates to a high-accuracy voltage ratio standard and implementation method. BACKGROUND

[0002] A voltage ratio standard device is a measurement device used to reproduce the ratio of alternating current voltage, and needs to meet two conditions of stability and traceability. At present, the alternating current voltage ratio standard device commonly used internationally mainly includes three types of resistive, capacitive and electromagnetic. The electromagnetic voltage ratio standard device has the advantages of simple principle, convenient use and stable reliability compared with the resistive and capacitive standard devices. The electromagnetic standard transformer has high accuracy and good stability, and is most widely used, but still has defects. In particular, during the error calibration test, if the rated transformation ratio of the standard transformer and the measured transformer is inconsistent, a multi-disc induction voltage divider is usually cascaded on the secondary side to obtain a consistent transformation ratio. After the electromagnetic standard transformer is cascaded with the multi-disc induction voltage divider, the error of the electromagnetic standard transformer generally has an overall deviation of (5-10×10 -6 ) levels. For the electromagnetic voltage transformer with an accuracy higher than 0.01 level, the error deviation will cause the accuracy to decrease by at least one level, so it is difficult to obtain a voltage ratio standard device with an accuracy of 0.005 level or higher in practice.

[0003] The prior art has attempted to compensate for the error of the electromagnetic voltage transformer. For example, if the ratio difference component and the angle difference component of the error of the electromagnetic voltage transformer are determined, the ratio difference component and the angle difference component can be compensated and adjusted by adding an additional transformer and an RC phase-shifting circuit. However, due to the inherent characteristics of the RC circuit, when the RC phase-shifting circuit is used to compensate for the orthogonal angle difference component, it is inevitable to cause the in-phase ratio difference component error. In addition, if the error of the electromagnetic voltage transformer deviates due to the performance change of the circuit elements, the calculated parameters of the compensation transformer and the RC phase-shifting circuit cannot be used to compensate for the error of the electromagnetic voltage transformer according to the predetermined calculation parameters, which will still cause the accuracy to decrease. In addition, the error deviation of the electromagnetic voltage transformer is particularly significant in high-frequency circuits. Due to the performance limitation of the current high-frequency capacitor, the frequency response and accuracy of the existing RC phase-shifting circuit at high frequency are greatly limited, thereby limiting the frequency range applicable to the error compensation means of the electromagnetic voltage transformer of the prior art.

[0004] Therefore, it is desirable in the art to have a method capable of conveniently implementing a high-accuracy voltage ratio standard, and to compensate for the error of the voltage ratio standard by a convenient and effective means when the wide-frequency error deviation of the voltage ratio standard exceeds the error limit, so as to maintain high accuracy for a long time. SUMMARY

[0005] According to a first aspect of the present application, a high-accuracy voltage ratio standarder is provided. The voltage ratio standarder comprises an electromagnetic voltage transformer with an accuracy of at least 1st grade, a ratio difference compensation module coupled with the electromagnetic voltage transformer, and an angle difference compensation module coupled with the electromagnetic voltage transformer and the ratio difference compensation module; the ratio difference compensation module comprises a same-phase voltage acquisition unit and a first precision adjustable resistor coupled with the same-phase voltage acquisition unit and the secondary winding of the electromagnetic voltage transformer, and the same-phase voltage acquisition unit is composed of a compensation voltage transformer coupled with the electromagnetic voltage transformer and a first auxiliary voltage transformer coupled with the compensation voltage transformer, wherein the parameters of the ratio difference compensation module are configured according to the ratio difference and the rated transformation ratio of the electromagnetic voltage transformer under the rated operating condition; the angle difference compensation module comprises a quadrature voltage acquisition unit coupled with the primary winding of the electromagnetic voltage transformer and a second precision adjustable resistor coupled with the quadrature voltage acquisition unit and the secondary winding of the first auxiliary voltage transformer, and the quadrature voltage acquisition unit is composed of a current transformer connected in series with the primary winding of the electromagnetic voltage transformer and a third precision resistor connected in parallel with the secondary side of the current transformer, or the quadrature voltage acquisition unit is composed of a fourth precision resistor coupled with the primary winding of the electromagnetic voltage transformer and a second auxiliary voltage transformer connected in parallel with the fourth precision resistor, wherein the parameters of the angle difference compensation module are configured according to the angle difference and the rated transformation ratio of the electromagnetic voltage transformer under the rated operating condition, the effective value of the input voltage of the voltage ratio standarder, and the effective value of the current flowing through the input side of the voltage ratio standarder; wherein the ratio difference compensation module is further configured to compensate the ratio difference of the voltage ratio standarder by adjusting the first precision adjustable resistor based on a predetermined ratio difference compensation amount, so that the ratio difference of the voltage ratio standarder is within the ratio difference limit value range required by the high-accuracy requirement, and the angle difference compensation module is further configured to compensate the angle difference of the voltage ratio standarder by adjusting the second precision adjustable resistor based on a predetermined angle difference compensation amount, so that the angle difference of the voltage ratio standarder is within the angle difference limit value range required by the high-accuracy requirement.

[0006] According to a preferred embodiment of the first aspect of the present application, the parameters of the ratio difference compensation module include the transformation ratio of the compensation voltage transformer, the transformation ratio of the first auxiliary voltage transformer, and the adjustment fineness of the first precision adjustable resistor.

[0007] According to a preferred embodiment of the first aspect of the present application, the parameters of the angle difference compensation module include the transformation ratio of the current transformer, the resistance value of the third precision resistor, and the adjustment fineness of the second precision adjustable resistor.

[0008] According to a preferred embodiment of the first aspect of the present application, the parameters of the angle difference compensation module include: the resistance value of the fourth precision resistor, the transformation ratio of the second auxiliary voltage transformer, and the adjustment fineness of the second precision adjustable resistor.

[0009] According to a preferred embodiment of the first aspect of the present application, the first precision adjustable resistor and the second precision adjustable resistor are both multi-turn adjustable resistors.

[0010] According to a preferred embodiment of the first aspect of the present application, the accuracy of the electromagnetic voltage transformer is at least 0.1 level.

[0011] According to a preferred embodiment of the first aspect of the present application, the accuracy of the voltage ratio standardizer is not less than 0.02 level.

[0012] According to a preferred embodiment of the first aspect of the present application, the predetermined ratio difference compensation amount and the predetermined angle difference compensation amount are calculated based on the measurement results of the ratio difference and the angle difference of the electromagnetic voltage transformer under the rated operating condition by using a phase-locked amplifier with a voltage resolution of at least 10 nV.

[0013] According to a preferred embodiment of the first aspect of the present application, the current transformer of the angle difference compensation module is an electromagnetic current transformer with an accuracy of 0.1 level or higher.

[0014] According to the second aspect of the present application, an implementation method of a high-accuracy voltage ratio standardizer is provided, which includes the following steps:

[0015] S1, obtaining an electromagnetic voltage transformer with an accuracy of at least 1 level and measuring the ratio difference and the angle difference thereof under the rated operating condition;

[0016] S2, calculating the ratio difference compensation amount and the angle difference compensation amount that the high-accuracy voltage ratio standardizer needs to apply to the electromagnetic voltage transformer based on the ratio difference and the angle difference of the electromagnetic voltage transformer;

[0017] S3, configuring the parameters of the ratio difference compensation module according to the ratio difference compensation amount and the rated transformation ratio of the electromagnetic voltage transformer and coupling the ratio difference compensation module to the electromagnetic voltage transformer, wherein the coupling of the ratio difference compensation module to the electromagnetic voltage transformer includes: coupling the compensation voltage transformer of the in-phase voltage acquisition unit to the electromagnetic voltage transformer, coupling the first auxiliary voltage transformer to the compensation voltage transformer, and connecting the first precision adjustable resistor to the first auxiliary voltage transformer and to the secondary winding of the electromagnetic voltage transformer, the parameters of the ratio difference compensation module being configured according to the ratio difference compensation amount and the rated transformation ratio of the electromagnetic voltage transformer, wherein the parameters of the ratio difference compensation module include: the transformation ratio of the compensation voltage transformer, the transformation ratio of the first auxiliary voltage transformer, and the resistance value of the first precision adjustable resistor, the parameters of the ratio difference compensation module satisfying the following formula: R x = Rf *ΔU f *K1*K2 / K0;

[0018] wherein, R x represents the adjusted resistance value of the first precision adjustable resistor, R f represents the nominal maximum resistance value of the first precision adjustable resistor, ΔU f represents the ratio difference compensation amount, K1 represents the transformation ratio of the compensation voltage transformer, K2 represents the transformation ratio of the first auxiliary voltage transformer, and K0 represents the rated transformation ratio of the electromagnetic voltage transformer;

[0019] S4, according to the angular difference compensation amount and the rated transformation ratio of the electromagnetic voltage transformer, configuring the parameters of the angular difference compensation module and connecting the angular difference compensation module to the electromagnetic voltage transformer and the ratio difference compensation module, thereby forming the voltage ratio standardizer, wherein connecting the angular difference compensation module to the electromagnetic voltage transformer and the ratio difference compensation module comprises: connecting the quadrature voltage acquisition unit to the primary winding of the electromagnetic voltage transformer, and connecting the second precision adjustable resistor to the quadrature voltage acquisition unit and to the secondary winding of the first auxiliary voltage transformer, wherein the quadrature voltage acquisition unit is composed of a current transformer and a third precision resistor connected in parallel with the secondary side of the current transformer, or the quadrature voltage acquisition unit is composed of a fourth precision resistor and a second auxiliary voltage transformer connected in parallel with the fourth precision resistor, the parameters of the angular difference compensation module are configured according to the angular difference and the rated transformation ratio of the electromagnetic voltage transformer under the rated operating condition, the effective value of the input voltage of the voltage ratio standardizer, and the effective value of the current flowing through the input side of the voltage ratio standardizer; wherein the parameters of the angular difference compensation module include the transformation ratio of the current transformer, the resistance value of the third precision resistor, and the resistance value of the second precision adjustable resistor, and the parameters of the angular difference compensation module satisfy the following formula: R Y = R δ *ΔU δ *U1*K3 / (K0*I*R1);

[0020] wherein, R Y represents the adjusted resistance value of the second precision adjustable resistor, R δ represents the nominal maximum resistance value of the second precision adjustable resistor, ΔU δ represents the angular difference compensation amount, U1 represents the effective value of the input voltage of the voltage ratio standardizer, K3 represents the transformation ratio of the current transformer, K0 represents the rated transformation ratio of the electromagnetic voltage transformer, I represents the effective value of the current flowing through the input side of the voltage ratio standardizer, and R1 represents the resistance value of the third precision resistor; or the parameters of the angular difference compensation module include the resistance value of the fourth precision resistor, the transformation ratio of the second auxiliary voltage transformer, and the resistance value of the second precision adjustable resistor, and the parameters of the angular difference compensation module satisfy the following formula: R Y = R δ *ΔU δ*U1*K4 / (K0*I*R2);

[0021] wherein R Y represents the adjustment resistance value of the second precision adjustable resistor, R δ represents the nominal maximum resistance value of the second precision adjustable resistor, ΔU δ represents the angle difference compensation amount, U1 represents the effective value of the input voltage of the voltage ratio standardizer, K4 represents the transformation ratio of the second auxiliary voltage transformer, K0 represents the rated transformation ratio of the electromagnetic voltage transformer, I represents the effective value of the current at the input side of the voltage ratio standardizer, and R2 represents the resistance value of the fourth precision resistor;

[0022] S5, measuring the ratio difference and the angle difference of the voltage ratio standardizer under the rated working condition and checking the grade of the ratio difference and the angle difference of the voltage ratio standardizer;

[0023] S6, judging whether the ratio difference or the angle difference of the voltage ratio standardizer exceeds the error limit value range required by the high accuracy, and if not, the checking is qualified and goes to step S8, otherwise, it continues to step S7;

[0024] S7, if the ratio difference of the voltage ratio standardizer exceeds the ratio difference limit value range required by the high accuracy, the ratio difference of the voltage ratio standardizer is compensated by adjusting the adjustment resistance value of the first precision adjustable resistor, and if the angle difference of the voltage ratio standardizer exceeds the angle difference limit value range required by the high accuracy, the angle difference of the voltage ratio standardizer is compensated by adjusting the adjustment resistance value of the second precision adjustable resistor, and then goes to step S5;

[0025] S8, completing the realization of the high accuracy voltage ratio standardizer, i.e. the ratio difference and the angle difference of the voltage ratio standardizer are both within the error limit value range required by the high accuracy after compensation.

[0026] According to the preferred embodiment of the second aspect of the present application, in step S4, the coupling of the quadrature voltage acquisition unit with the primary winding of the electromagnetic voltage transformer comprises: connecting the primary side of the current transformer in series with the primary winding of the electromagnetic voltage transformer, connecting the third precision resistor in parallel with the secondary side of the current transformer, and connecting the second precision adjustable resistor in parallel with the third precision resistor and in connection with the secondary winding of the first auxiliary voltage transformer.

[0027] According to the preferred embodiment of the second aspect of the present application, in step S4, the coupling of the quadrature voltage acquisition unit with the primary winding of the electromagnetic voltage transformer comprises: connecting the fourth precision resistor in series with the primary winding of the electromagnetic voltage transformer, and connecting the second auxiliary voltage transformer in parallel with the fourth precision resistor.

[0028] According to the preferred embodiment of the second aspect of the present application, the first precision adjustable resistor and the second precision adjustable resistor are both set as multi-turn adjustable resistors.

[0029] According to a preferred embodiment of the second aspect of the application, the accuracy of the voltage ratio standard realized by the method is not less than 0.02 level.

[0030] According to a preferred embodiment of the second aspect of the application, the electromagnetic voltage transformer is selected to be an electromagnetic voltage transformer with an accuracy of at least 0.1 level.

[0031] According to a preferred embodiment of the second aspect of the application, the measurement of the ratio difference and the phase difference in the method steps is performed by using a phase lock amplifier with a voltage resolution of at least 10 nV.

[0032] According to a preferred embodiment of the second aspect of the application, the current transformer of the phase difference compensation module is an electromagnetic current transformer with an accuracy of 0.1 level or higher.

[0033] The high-accuracy voltage ratio standard and the implementation method provided by the application have the following advantages: (1) the high-accuracy voltage ratio standard can be conveniently realized by using a conventional electromagnetic voltage transformer; (2) in the case where the error of the voltage ratio standard exceeds the rated limit range, the ratio difference and the phase difference of the voltage ratio standard can be respectively adjusted by using the continuously adjustable error compensation, so that the voltage ratio standard can conveniently achieve high accuracy; (3) the ratio difference compensation module of the voltage ratio standard can compensate the ratio difference voltage component in phase with the secondary voltage vector, and the phase difference compensation module of the voltage ratio standard uses the orthogonal voltage acquisition unit to compensate the phase difference voltage component orthogonal to the secondary voltage vector, compared with the existing RC phase shift circuit, the accuracy of the phase difference compensation is higher, and the high-frequency response performance is better. BRIEF DESCRIPTION OF DRAWINGS

[0034] One or more embodiments of the application are exemplarily illustrated by the corresponding drawings, which do not constitute a limitation on the embodiments, and the elements with the same reference numerals in the drawings represent similar elements, unless otherwise stated, and the drawings do not constitute a proportional limit.

[0035] Fig. 1 shows a circuit schematic diagram of a voltage ratio standard according to one embodiment of the application;

[0036] Fig. 2 shows a circuit schematic diagram of a voltage ratio standard according to another embodiment of the application;

[0037] Fig. 3 shows a circuit schematic diagram of a voltage ratio standard coupled with an alternating voltage source for error compensation according to the application;

[0038] Fig. 4 shows a flowchart of an implementation method of a voltage ratio standard according to one embodiment of the application;

[0039] Fig. 5 shows an error compensation vector diagram of the voltage ratio standard according to one embodiment of the present application.

[0040] 1 - voltage ratio standard, 2 - electromagnetic voltage transformer, 3 - ratio error compensation module, 30 - in-phase voltage acquisition unit, 32 - first precision adjustable resistor, 301 - compensation voltage transformer, 303 - first auxiliary voltage transformer, 4 - phase error compensation module, 40 - quadrature voltage acquisition unit, 42 - second precision adjustable resistor, 401 - current transformer, 402 - fourth precision resistor, 403 - third precision resistor, 404 - second auxiliary voltage transformer, A, B - input terminals of the voltage ratio standard, a, b - output terminals of the voltage ratio standard, b 21 - low end of the secondary winding of the electromagnetic voltage transformer, b 22 - tap of the ratio error compensation module, U1 - input voltage of the voltage ratio standard, U 11 - primary voltage of the electromagnetic voltage transformer, U 21 - secondary voltage of the electromagnetic voltage transformer, U X - ratio error compensation voltage, U Y - phase error compensation voltage, U 22 - output voltage of the secondary voltage of the electromagnetic voltage transformer after ratio error compensation, U2 - output voltage of the voltage ratio standard, R1 - resistance value of the third precision resistor, R X - adjustment resistance value of the first precision adjustable resistor, R Y - adjustment resistance value of the second precision adjustable resistor, R2 - resistance value of the fourth precision resistor, AC - AC voltage source. DETAILED DESCRIPTION

[0041] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0042] It should be noted that the various features of the embodiments of the present application can be combined with each other if there is no conflict, and all are within the protection scope of the present application. In addition, although the functional modules are divided in the schematic diagram, and the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the order in the schematic diagram or the flowchart.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application, so that the purposes and advantages of the present application are more apparent. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0045] Referring to FIG. 1, a circuit schematic diagram of a voltage ratio standarder 1 according to an embodiment of the present application is shown. The voltage ratio standarder 1 is composed of an electromagnetic potential transformer (PT) 2, a ratio and difference compensation module 3 coupled with the electromagnetic potential transformer 2, and an angle difference compensation module 4 coupled with the electromagnetic potential transformer 2 and the ratio and difference compensation module 3. Preferably, the accuracy of the electromagnetic potential transformer 2 reaches at least 0.1 level. The electromagnetic potential transformer 2 includes a core and a primary winding and a secondary winding wound on the core.

[0046] Continuing to refer to FIG. 1, the ratio and difference compensation module 3 includes a same-phase voltage acquisition unit 30 and a first precision adjustable resistor 32 coupled with the secondary winding of the electromagnetic potential transformer 2 and connected in parallel with the same-phase voltage acquisition unit 30. The same-phase voltage acquisition unit 30 is composed of a compensation voltage transformer 301 coupled with the electromagnetic potential transformer 2 and a first auxiliary voltage transformer 303 coupled with the compensation voltage transformer 301. Specifically, the compensation voltage transformer 301 can be coupled to the compensation voltage transformer 301 by winding the proportional winding uniformly on the core of the electromagnetic potential transformer 2, thereby forming an electromagnetic potential transformer with a certain rated transformation ratio. The proportional winding of the compensation voltage transformer 301 is connected in parallel with the primary winding of the first auxiliary voltage transformer 303, the secondary winding of the first auxiliary voltage transformer 303 is connected to the two fixed terminals of the first precision adjustable resistor 32, and the middle pin of the first precision adjustable resistor 32 is connected to the low end b of the secondary winding of the electromagnetic potential transformer 2. 21 The transformation ratio of the compensation voltage transformer 301, the transformation ratio of the first auxiliary voltage transformer 303, and the adjustment fineness of the first precision adjustable resistor 32 can be configured according to the ratio and difference of the electromagnetic potential transformer 2 under the rated working condition and the rated transformation ratio. The angle difference compensation module 4 includes a quadrature voltage acquisition unit 40 coupled with the primary winding of the electromagnetic potential transformer 2 and a second precision adjustable resistor 42 coupled with the quadrature voltage acquisition unit 40 and the secondary winding of the first auxiliary voltage transformer 303.

[0047] In the embodiment shown in Fig. 1, the orthogonal voltage acquisition unit 40 is composed of a current transformer 401 connected in series with the primary winding of the electromagnetic voltage transformer 2, and a third precision resistor 403 connected in parallel with the secondary side of the current transformer 401. Specifically, the primary side of the current transformer 401 is connected in series with the primary winding of the electromagnetic voltage transformer 2, the third precision resistor 403 is connected in parallel with the secondary side of the current transformer 401, the two fixed ends of the second precision adjustable resistor 42 are connected in parallel with the third precision resistor 403, and the middle pin of the second precision adjustable resistor 42 is connected to the tap b of the angle difference compensation module. 22 The transformation ratio of the current transformer 401, the resistance R1 of the third precision resistor 403, and the adjustment fineness of the second precision adjustable resistor 42 are configured according to the angle difference and the rated transformation ratio of the electromagnetic voltage transformer 2 under the rated operating condition, the effective value of the input voltage of the voltage ratio standardizer 1, and the effective value of the current flowing through the input side of the voltage ratio standardizer 1.

[0048] In the embodiment shown in Fig. 1, the current transformer 401 is configured such that one end of its primary side is connected to the low end of the primary winding of the electromagnetic voltage transformer 2, so that the high end of the primary winding of the electromagnetic voltage transformer 2 and the other end of the primary side of the current transformer 401 form the input terminals A, B of the voltage ratio standardizer 1, and the high end of the secondary winding of the electromagnetic voltage transformer 2 and the tap of the angle difference compensation module 4 constitute the output terminals a, b of the voltage ratio standardizer 1. The ratio difference compensation module 3 is configured to compensate the ratio difference of the voltage ratio standardizer 1 to a predetermined ratio difference compensation amount by adjusting the adjustment resistance R X of the first precision adjustable resistor 32, so that the ratio difference of the voltage ratio standardizer is within the range of the ratio difference limit value with high accuracy requirement. The angle difference compensation module 4 is configured to compensate the angle difference of the voltage ratio standardizer 1 to a predetermined angle difference compensation amount by adjusting the adjustment resistance R Y of the second precision adjustable resistor 42, so that the angle difference of the voltage ratio standardizer is within the range of the angle difference limit value with high accuracy requirement. The connection between the compensation voltage transformer 301 and the first auxiliary voltage transformer 303 can be selected as positive connection or negative connection according to the positive or negative of the ratio difference of the voltage ratio standardizer 1, and the current transformer 401 can also be selected as positive connection or negative connection according to the positive or negative of the angle difference of the voltage ratio standardizer 1.

[0049] Figure 2 shows a circuit schematic of a voltage ratio standard according to another embodiment of the present application. The difference from the embodiment shown in Figure 1 is that the quadrature voltage acquisition unit 40 is composed of a fourth precision resistor 402 coupled to the primary winding of the electromagnetic voltage transformer 2, and a second auxiliary voltage transformer 404 connected in parallel with the fourth precision resistor 402. Specifically, one end of the fourth precision resistor 402 is coupled to the low end of the primary winding of the electromagnetic voltage transformer 2, so that the high end of the primary winding of the electromagnetic voltage transformer 2 and the other end of the fourth precision resistor 402 form the input terminals A, B of the voltage ratio standard 1, the fourth precision resistor 402 is connected in parallel with the primary winding of the second auxiliary voltage transformer 404, both fixed terminals of the second precision adjustable resistor 42 are connected to the secondary winding of the second auxiliary voltage transformer 404, and the middle pin of the second precision adjustable resistor 42 is coupled to the tap b of the ratio difference compensation module 22 , the high end of the secondary winding of the electromagnetic voltage transformer 2 and the tap of the angle difference compensation module 4 form the output terminals a, b of the voltage ratio standard 1.

[0050] In practice, the ratio difference and the angle difference of the electromagnetic voltage transformer 2 and the voltage ratio standard 1 can be obtained by the measurement method described in the existing JJG 314-2010 regulation, or alternatively, by the comparison measurement difference method using a lock-in amplifier. Preferably, the measurement of the ratio difference and the angle difference is performed using a lock-in amplifier with a voltage resolution of at least 10 nV, and then the predetermined ratio difference compensation and the angle difference compensation can be calculated according to the measurement results. Alternatively, the ratio difference compensation and the angle difference compensation can also be obtained by other measurement methods known to those skilled in the art.

[0051] Based on the item-by-item approximation principle, the ratio difference compensation module 3 and the angle difference compensation module 4 are respectively used to compensate the ratio difference compensation amount ΔU f and the angle difference compensation amount ΔU δ of the electromagnetic voltage transformer 2 to achieve item-by-item approximation compensation. The significant advantage is that even if the voltage ratio standard 1 has an error offset due to changes in the performance of circuit elements, the offset ratio difference and angle difference can still be conveniently compensated by the ratio difference compensation module 3 and the angle difference compensation module 4, respectively, and the compensation process of the ratio difference and the angle difference is continuous, linear and controllable, thereby ensuring that the voltage ratio standard 1 remains at a high accuracy after error compensation.

[0052] In particular, referring to FIG. 3, a circuit diagram of the voltage ratio standardizer 1 coupled with an AC voltage source for error compensation is shown. In particular, the AC voltage source AC can output an AC voltage signal with a rated primary voltage of the electromagnetic voltage transformer 2 and corresponding rated measurement points. In the embodiment shown in FIG. 3, the quadrature voltage acquisition unit 40 of the phase difference compensation module 4 is configured to be coupled to the low end of the primary winding of the electromagnetic voltage transformer 2. The main function of the quadrature voltage acquisition unit 40 is to acquire a voltage component that is orthogonal to the secondary voltage vector. The basic principle of acquiring the quadrature voltage component in the present application is that the core of the electromagnetic voltage transformer is usually made of soft magnetic material with high magnetic permeability and low hysteresis, the secondary voltage vector of the electromagnetic voltage transformer is generally 90° lagged behind the change of the core magnetic flux, and the core magnetic flux is proportional to the current flowing through the primary winding and has low hysteresis. Therefore, by extracting the voltage corresponding to the current flowing through the primary winding through the quadrature voltage acquisition unit, a phase difference compensation voltage vector that is generally orthogonal to the ratio error compensation voltage vector of the electromagnetic voltage transformer 2 can be obtained.

[0053] The quadrature voltage acquisition unit 40 in FIG. 3 can be composed of a current transformer 401 connected in series with the primary winding of the electromagnetic voltage transformer 2, and a third precision resistor 403 connected in parallel with the secondary side of the current transformer 401, as shown in FIG. 1; or alternatively, composed of a fourth precision resistor 402 connected with the primary winding of the electromagnetic voltage transformer 2, and a second auxiliary voltage transformer 404 connected in parallel with the fourth precision resistor 402, as shown in FIG. 2. The phase difference compensation module 4 can realize the phase difference compensation amount ΔU δ corresponding to the phase difference compensation voltage.

[0054] Referring to FIGS. 1-3 simultaneously, the ratio error compensation module 3 in the dashed box includes a compensation voltage transformer 301 coupled with the electromagnetic voltage transformer 2, a first auxiliary voltage transformer 303 coupled with the compensation voltage transformer 301, and a first precision adjustable resistor 32 connected in parallel with the first auxiliary voltage transformer 303 and coupled with the secondary winding of the electromagnetic voltage transformer 2, and the compensation voltage transformer 301 and the first auxiliary voltage transformer 303 constitute the in-phase voltage acquisition unit 30. By configuring the parameters of the ratio error compensation module 3, i.e., the transformation ratio K1 of the compensation voltage transformer 301, the transformation ratio K2 of the first auxiliary voltage transformer 303, and the resistance value of the first precision adjustable resistor 32, so that the parameters of the ratio error compensation module 3 satisfy the following formula (1): x = R f * ΔU f * K1 * K2 / K0 Formula (1)

[0055] wherein R x represents the adjusted resistance value of the first precision adjustable resistor 32, and Rf represents the nominal maximum resistance value of the first precision adjustable resistor 32, K0 represents the rated transformation ratio of the electromagnetic voltage transformer, and the ratio error compensation module 3 is capable of further compensating the secondary voltage U 21 of the electromagnetic voltage transformer 2 with the ratio error compensation amount ΔU f corresponding to the ratio error compensation voltage U x In FIG. 3, the secondary voltage U 21 of the electromagnetic voltage transformer 2 is compensated with the ratio error compensation voltage U 22 . 22 is actually the voltage difference between the output end a of the voltage ratio standard 1 and the tap b of the ratio error compensation module 3. 22 .

[0056] The angle error compensation module 4 in the dashed box in FIG. 1 includes a current transformer 401 connected in series with the electromagnetic voltage transformer 2, a third precision resistor 403 connected in parallel with the current transformer 401, and a second precision adjustable resistor 42 connected in parallel with the third precision resistor 403 and coupled with the secondary winding of the first auxiliary voltage transformer 303, and the current transformer 401 and the third precision resistor 403 constitute a quadrature voltage acquisition unit 40. The current transformer 401 is preferably an electromagnetic current transformer with an accuracy of 0.1 level or higher. By configuring the parameters of the angle error compensation module 4, i.e., the transformation ratio K3 of the current transformer 401, the resistance R1 of the third precision resistor 403, and the resistance of the second precision adjustable resistor 42, the parameters of the angle error compensation module 4 satisfy the following formula (2): R Y = R δ * ΔU δ * U1 * K3 / (K0 * I * R1) Formula (2)

[0057] wherein R Y is the adjusted resistance of the second precision adjustable resistor 42, R δ is the nominal maximum resistance value of the second precision adjustable resistor 42, U1 represents the effective value of the input voltage of the voltage ratio standard 1, K0 represents the rated transformation ratio of the electromagnetic voltage transformer 1, I represents the effective value of the current at the input side of the voltage ratio standard 1, and the angle error compensation module 4 is capable of further compensating the voltage U 22 of the electromagnetic voltage transformer 2 after ratio error compensation with the angle error compensation amount ΔU δ corresponding to the angle error compensation voltage U Y . Preferably, the nominal maximum resistance value R δ of the second precision adjustable resistor 42 is at least 100 times or more than the resistance R1 of the third precision resistor 403, so that the current at the input side of the voltage ratio standard 1 mainly flows through the third precision resistor 403 after being converted by the current transformer 401.

[0058] The angle difference compensation module 4 in the dashed box shown in FIG. 2 comprises a fourth precision resistor 402 coupled with the primary winding of the electromagnetic voltage transformer 2, a second auxiliary voltage transformer 404 connected in parallel with the fourth precision resistor 402, and a second precision adjustable resistor 42 connected in parallel with the secondary winding of the second auxiliary voltage transformer 404 and coupled with the secondary winding of the first auxiliary voltage transformer 303, the fourth precision resistor 402 and the second auxiliary voltage transformer 404 constituting a quadrature voltage acquisition unit 40. By configuring the parameters of the angle difference compensation module 4, i.e., the resistance R2 of the fourth precision resistor 402, the transformation ratio K4 of the second auxiliary voltage transformer 404, and the resistance of the second precision adjustable resistor 42, the parameters of the angle difference compensation module 4 satisfy the following formula (3): Y δ * ΔU δ * U1 * K4 / (K0 * I * R2) Formula (3)

[0059] wherein R Y represents the adjusted resistance of the second precision adjustable resistor 42, R δ represents the nominal maximum resistance of the second precision adjustable resistor 42, ΔU δ represents the angle difference compensation amount, U1 represents the effective value of the input voltage of the voltage ratio standard 1, K0 represents the rated transformation ratio of the electromagnetic voltage transformer 1, and I represents the effective value of the current at the input side of the voltage ratio standard, so that the angle difference compensation module 4 can further compensate the voltage U 22 compensated by the ratio difference compensation module 3 to the electromagnetic voltage transformer 2 by the angle difference compensation amount ΔU δ , so that the corresponding angle difference compensation voltage U Y .

[0060] As shown in FIG. 3, the secondary voltage U 21 of the electromagnetic voltage transformer 2 is compensated by the ratio difference compensation and the angle difference compensation, and is marked as U2, and U2 is actually the voltage difference between the output terminals a and b of the voltage ratio standard 1.

[0061] ​Referring to FIG. 4, a flow chart of an implementation method of the voltage ratio standardizer 1 according to an embodiment of the present application is shown. The method comprises the following steps: S1, obtaining an electromagnetic voltage transformer 2 with an accuracy of at least 1st level and measuring its ratio error and phase error under rated operating conditions; S2, calculating the ratio error compensation amount and the phase error compensation amount to be applied to the electromagnetic voltage transformer 2 based on the ratio error and the phase error of the electromagnetic voltage transformer 2; S3, configuring parameters of the ratio error compensation module 3 according to the ratio error compensation amount and the rated transformation ratio of the electromagnetic voltage transformer 2 and coupling the ratio error compensation module 3 to the electromagnetic voltage transformer 2, wherein coupling the ratio error compensation module 3 to the electromagnetic voltage transformer 2 comprises: coupling the compensation voltage transformer 301 of the in-phase voltage acquisition unit 30 to the electromagnetic voltage transformer 2, coupling the first auxiliary voltage transformer 303 to the compensation voltage transformer 301, and connecting the first precision adjustable resistor 32 to the first auxiliary voltage transformer 303 and to the secondary winding of the electromagnetic voltage transformer 2, the parameters of the ratio error compensation module 3 being configured according to the ratio error compensation amount and the rated transformation ratio of the electromagnetic voltage transformer 2, wherein the parameters of the ratio error compensation module 3 comprise: the transformation ratio of the compensation voltage transformer 301, the transformation ratio of the first auxiliary voltage transformer 303, and the resistance value of the first precision adjustable resistor 32; S4, configuring parameters of the phase error compensation module 4 according to the phase error compensation amount and the rated transformation ratio of the electromagnetic voltage transformer 2 and coupling the phase error compensation module 4 to the electromagnetic voltage transformer 2 and the ratio error compensation module 3, thereby forming the voltage ratio standardizer 1, wherein coupling the phase error compensation module 4 to the electromagnetic voltage transformer 2 and the ratio error compensation module 3 comprises: coupling the quadrature voltage acquisition unit 40 to the primary winding of the electromagnetic voltage transformer 2, and coupling the second precision adjustable resistor 42 to the quadrature voltage acquisition unit 40 and to the secondary winding of the first auxiliary voltage transformer 303, wherein the quadrature voltage acquisition unit 40 is composed of the current transformer 401 and the third precision resistor 403 connected to the secondary side of the current transformer 401 (as shown in FIG. 1), or the quadrature voltage acquisition unit 40 is composed of the fourth precision resistor 402 and the second auxiliary voltage transformer 404 connected to the fourth precision resistor 402 (as shown in FIG. 2), the parameters of the phase error compensation module 4 being configured according to the phase error and the rated transformation ratio of the electromagnetic voltage transformer 2 under the rated operating conditions, the effective value of the input voltage of the voltage ratio standardizer 1, and the effective value of the current flowing through the input side of the voltage ratio standardizer 1; S5, measuring the ratio error and the phase error of the voltage ratio standardizer 1 under the rated operating conditions, and checking the levels of the ratio error and the phase error of the voltage ratio standardizer 1; S6, determining whether the ratio error or the phase error of the voltage ratio standardizer 1 exceeds the error limit value range required by the high accuracy, if not, the checking is qualified and goes to step S8, otherwise, it continues to step S7; S7, if the ratio error of the voltage ratio standardizer 1 exceeds the ratio error limit value range required by the high accuracy, adjusting the adjustment resistance value R xThe ratio error of voltage proportional standard 1 is compensated. If the angle error of voltage proportional standard 1 exceeds the angle error limit required for high accuracy, the adjustment value R of the second precision adjustable resistor 42 is adjusted. Y The angle difference of voltage proportional standard 1 is compensated, and then the process proceeds to steps S5 and S8 to complete the realization of a high-accuracy voltage proportional standard. That is, after compensation, the ratio difference and angle difference of voltage proportional standard 1 are both within the error limit range required for high accuracy.

[0062] It is understood that a significant advantage of the ratio difference compensation module 3 configured according to this application is that when the voltage ratio standard 1 experiences a ratio difference deviation and requires further compensation, it can still be compensated by continuously adjusting the adjustment resistance value R of the first precision adjustable resistor 32. x This achieves accurate compensation for the ratio difference. Similarly, a significant advantage of the angle difference compensation module 4 is that when the voltage proportional standard 1 experiences an angle difference offset and requires further compensation, it can also be compensated by continuously adjusting the resistance value R of the second precision adjustable resistor 42. Y Accurate compensation of phase angle difference is achieved. For the phase difference compensation module 3 and the phase angle difference compensation module 4, it should be noted that the function of the in-phase voltage acquisition unit 30 is to acquire the voltage component that is approximately in phase with the secondary voltage vector, and the function of the quadrature voltage acquisition unit 40 is to acquire the voltage component that is approximately orthogonal to the secondary voltage vector. Therefore, in terms of design, the voltage drop across the voltage acquisition unit 40 of the input voltage U1 should be as small as possible compared to the input voltage U1. Furthermore, the first auxiliary voltage transformer 303 and the second auxiliary voltage transformer 404 are preferably electromagnetic voltage transformers with cores made of low-hysteresis soft magnetic material.

[0063] Figure 5 shows a vector diagram of error compensation for a voltage proportional standard according to an embodiment of this application. Referring to both Figures 3 and 5, assuming U1 is the input voltage of voltage proportional standard 1, the error compensation process of voltage proportional standard 1 is as follows: First, the secondary voltage U1 of electromagnetic voltage transformer 2 is compensated by the ratio difference compensation module 3. 21 Vector-based voltage difference compensation U x The compensation, the secondary voltage U of electromagnetic voltage transformer 2 21 The voltage vector change after ratio compensation is U. 22 Then, the voltage vector U of the electromagnetic voltage transformer 2 after ratio difference compensation is adjusted by the angle difference compensation module 4. 22 Further perform angle difference compensation voltage U Y The compensation ultimately achieves a vector voltage ΔU = U for the electromagnetic voltage transformer 2. x +j*U Y Error compensation, where j is the imaginary unit, and the secondary voltage U of electromagnetic voltage transformer 2. 21The vector after compensation of the vector voltage ΔU changes to U2, i.e. the output voltage of the voltage ratio standard 1. In Fig. 5, the ratio difference compensation voltage U x is in a substantially orthogonal relationship with the vector of the angle difference compensation voltage U Y , and their vector sum is the vector voltage ΔU to be compensated, where α is the included angle of the vector voltage ΔU to be compensated with respect to the secondary voltage vector U 21 , and θ is the final angle compensation amount.

[0064] For the voltage ratio standard 1 formed by adding the ratio difference compensation module 3 and the angle difference compensation module 4 to the electromagnetic voltage transformer 2, in some cases, the ratio difference or the phase difference between the output voltage U2 after the ratio difference compensation and the angle difference compensation based on the secondary voltage of the electromagnetic voltage transformer 2 and the input voltage U1 of the voltage ratio standard 1 can still not meet the ratio difference and the angle difference required by the high-accuracy voltage ratio standard 1, which is similar to the error offset phenomenon described in the background art. In this case, only the ratio difference and the angle difference of the voltage ratio standard 1 under the rated operating condition need to be measured and the predetermined ratio difference compensation amount or the predetermined angle difference compensation amount required to achieve the high-accuracy voltage ratio standard need to be calculated, and the ratio difference between the output voltage and the input voltage of the voltage ratio standard 1 can still be compensated by the ratio difference compensation module 3 by a predetermined ratio difference compensation amount, and the angle difference between the output voltage and the input voltage of the voltage ratio standard 1 can still be compensated by the angle difference compensation module 4 by a predetermined angle difference compensation amount.

[0065] Specifically, if the ratio difference of the voltage ratio standard 1 exceeds the ratio difference limit value range required by the high accuracy, the ratio difference of the voltage ratio standard 1 can be compensated by adjusting the adjustment resistance R x of the first precision adjustable resistor 32 until the ratio difference measured by the voltage ratio standard 1 under the rated operating condition is within the ratio difference limit value range required by the high accuracy; similarly, if the angle difference of the voltage ratio standard 1 exceeds the angle difference limit value range required by the high accuracy, the angle difference of the voltage ratio standard 1 can be compensated by adjusting the adjustment resistance R Y of the second precision adjustable resistor 42 until the angle difference measured by the voltage ratio standard 1 under the rated operating condition is within the angle difference limit value range required by the high accuracy. In this way, the voltage ratio standard 1 can be ensured to remain in high accuracy after error compensation. The vector diagram of the error compensation of the voltage ratio standard 1 is similar to the description above with reference to Fig. 5, only the vectors in the figure need to be replaced by the corresponding vectors of the voltage ratio standard 1, for example, U 21 , U x , and U Y are respectively understood as the secondary voltage vector, the ratio difference compensation voltage, and the angle difference compensation voltage of the voltage ratio standard 1, and the compensation principle is the same as described above, which will not be described here.

[0066] The significant advantages of the present application include: (1) the voltage ratio standarder with accuracy not less than 0.02 level is conveniently realized by using the common electromagnetic voltage transformer with accuracy at least reaching 1 level; (2) in the case that the error of the voltage ratio standarder exceeds the rated limit value range, the ratio error and the angle error of the voltage ratio standarder can be respectively adjusted by the continuously adjustable error compensation, so that the voltage ratio standarder reaches high accuracy, and the compensation process of the ratio error and the angle error is continuous, linear and controllable, thereby ensuring that the error of the voltage ratio standarder is within the error limit value range of the high accuracy requirement; (3) the angle error compensation module of the voltage ratio standarder adopts the orthogonal voltage acquisition unit composed of the current transformer in series with the primary winding of the electromagnetic voltage transformer, the precision resistor connected in parallel with the secondary side of the current transformer, or the precision resistor connected with the primary winding of the electromagnetic voltage transformer and the auxiliary voltage transformer connected in parallel with the precision resistor, combined with the precision adjustable resistor to compensate the angle error voltage component orthogonal to the secondary voltage vector, compared with the existing RC phase-shifting circuit, the accuracy of the angle error compensation is higher, and the high-frequency response performance is better, which can be applied to the wideband error compensation of the voltage ratio standarder.

[0067] It is well known to those skilled in the art that, for the electromagnetic voltage transformer with accuracy reaching 0.01 level, the ratio error and the angle error are in the order of 10 -5 According to the embodiment of the present application, for the ratio error compensation module 3 of the 0.01 level voltage transformer with rated transformation ratio of 1, the transformation ratio K1 of the compensation voltage transformer can be set to 100, the transformation ratio K2 of the first auxiliary voltage transformer can be set to 100, if the nominal maximum resistance of the first precision adjustable resistor 32 is selected to be 10 kΩ and the step adjustment resistance of the first precision adjustable resistor 42 is about 1 Ω, then the ratio error component in the range of 10 -5 ~ 10 -8 orders of magnitude can be accurately and effectively compensated. For the angle error compensation module 4, the transformation ratio K3 of the current transformer and the appropriate third precision resistor 403 can be selected according to the effective value U1 of the input voltage of the voltage ratio standarder 1 and the effective value I of the current at the input side of the voltage ratio standarder 1, so that the current effective value I, the resistance R1 of the third precision resistor 403, the input voltage U1 of the voltage ratio standarder 1 and the transformation ratio K1 of the compensation voltage transformer and the transformation ratio K2 of the first auxiliary voltage transformer satisfy the following relationship: K3*U1 / (I*R1)=K1*K2=10000;

[0068] Or select the ratio K4 of the second auxiliary voltage transformer and the appropriate fourth precision resistor 402, so that the current effective value I, the resistance R1 of the fourth precision resistor 402, the input voltage U1 of the voltage ratio standarder 1 and the ratio K1 of the compensation voltage transformer and the ratio K2 of the first auxiliary voltage transformer satisfy the following relationship: K4*U1 / (I*R1) = K1*K2 = 10000;

[0069] If the nominal maximum resistance of the second precision adjustable resistor 42 is selected as 10kΩ and the step adjustment resistance of the second precision adjustable resistor 42 is about 1Ω, the 10 -5 ~10 -8 order of magnitude range can be accurately and effectively compensated. The equal-ratio voltage ratio standarder realized by the method proposed in the present application for ratio error compensation and phase error compensation of the electromagnetic voltage transformer can reach 0.005 level or higher level.

[0070] It should be noted that the above description of the 0.005 level or higher level voltage ratio standarder based on the 0.01 level electromagnetic voltage transformer with a rated ratio of 1 is only exemplary and not limiting. In practice, the rated ratio of the electromagnetic voltage transformer can be selected according to actual needs, for example, a high-voltage electromagnetic voltage transformer based on a certain rated ratio can be compensated for ratio error and phase error by the method proposed in the present application, and then an equal-ratio high-accuracy high-voltage ratio standarder can be realized. Those skilled in the art can understand that the high-voltage ratio standarder with a commonly used ratio in practice can be conveniently improved in accuracy by compensating for ratio error and phase error based on an equal-ratio electromagnetic voltage transformer by the method proposed in the present application.

[0071] In one embodiment, in order to more clearly and intuitively show the technical advantages of the above-mentioned voltage ratio standarder and implementation method, an experimental example is given, and those skilled in the art can understand that the following experimental example is only illustrative and not limiting to the above-mentioned voltage ratio standarder and implementation method.

[0072] Based on the 1:1 ratio 0.01 level electromagnetic voltage transformer (i.e., K0 = 1) developed by the applicant, a higher-accuracy voltage ratio standarder can be formed by using the method proposed in the present application. By using a phase-locked amplifier with a voltage resolution of 1nV, the wideband error ε of the 0.01 level electromagnetic voltage transformer under the rated primary voltage U1 can be accurately measured by using the comparison difference method, and the ratio error f and the phase error δ at each frequency 53Hz, 106Hz and 1000Hz are shown in Table 1 as follows:

[0073] Table 1: Wideband error of 0.01 level electromagnetic voltage transformer

[0074] The applicant expects that the error compensation method of the voltage ratio standard implement according to the present application can reduce the error of the 0.01-grade electromagnetic voltage transformer to 10 -5 ~10 -6 ~10 -8 orders of magnitude. By adding the ratio error compensation module and the angle error compensation module to the above-mentioned 0.01-grade electromagnetic voltage transformer, the wideband error of the 0.01-grade electromagnetic voltage transformer after the ratio error compensation and the angle error compensation can be accurately measured by the comparison error measurement method. The ratio error f and the angle error δ at each frequency of 53 Hz, 106 Hz and 1000 Hz are shown in Table 2 below:

[0075] Table 2: Wideband error of the 0.01-grade electromagnetic voltage transformer after error compensation

[0076] As can be seen from Table 2, after the error compensation of the 0.01-grade electromagnetic voltage transformer, the ratio error and the angle error are reduced from 10 -5 ~10 -7 orders of magnitude, that is, the accuracy of the voltage ratio standard implement obtained by the method according to the present application is improved by more than three grades compared with the original 0.01-grade electromagnetic voltage transformer. According to the error measurement results of the voltage ratio standard implement measured by the comparison error measurement method at each rated measurement point according to the JJG 314-2010 regulation, the accuracy of the voltage ratio standard implement obtained by the method according to the present application theoretically reaches 0.0001 grade, which can be used as a high-accuracy wideband voltage ratio standard implement.

[0077] As can be further seen from Table 2, since the angle error compensation module of the voltage ratio standard implement uses a current transformer to obtain the orthogonal angle error compensation voltage, compared with the existing RC phase-shifting circuit, the accuracy of the angle error compensation is higher, and has good high-frequency response performance, which is especially suitable for the wideband error compensation of the voltage ratio standard implement.

[0078] Those skilled in the art can understand that all or part of the processes in the method for implementing the above embodiments can be instructed by a computer program to relevant hardware, and the computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the embodiments of the above methods can be included. Wherein, any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlmnk) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0079] The technical features of the above embodiments can be combined in any way. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0080] It should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; under the idea of the present application, the technical features between the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be simple, they are not provided in detail; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. For those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application.

Claims

1. A high-accuracy voltage ratio standardizer characterized by, The voltage ratio standarder comprises an electromagnetic voltage transformer with an accuracy of at least 1 level, a ratio difference compensation module coupled with the electromagnetic voltage transformer, and an angle difference compensation module coupled with the electromagnetic voltage transformer and the ratio difference compensation module. The ratio difference compensation module comprises a same-phase voltage acquisition unit and a first precision adjustable resistor connected in parallel with the same-phase voltage acquisition unit and coupled with a secondary winding of the electromagnetic voltage transformer, and the same-phase voltage acquisition unit is composed of a compensation voltage transformer coupled with the electromagnetic voltage transformer and a first auxiliary voltage transformer coupled with the compensation voltage transformer, wherein parameters of the ratio difference compensation module are configured according to a ratio difference and a rated transformation ratio of the electromagnetic voltage transformer under a rated operating condition. The angle difference compensation module comprises a quadrature voltage acquisition unit coupled with a primary winding of the electromagnetic voltage transformer and a second precision adjustable resistor coupled with the quadrature voltage acquisition unit and coupled with a secondary winding of the first auxiliary voltage transformer, and the quadrature voltage acquisition unit is composed of a current transformer connected in series with the primary winding of the electromagnetic voltage transformer and a third precision resistor connected in parallel with a secondary side of the current transformer, or the quadrature voltage acquisition unit is composed of a fourth precision resistor coupled with the primary winding of the electromagnetic voltage transformer and a second auxiliary voltage transformer connected in parallel with the fourth precision resistor, wherein parameters of the angle difference compensation module are configured according to an angle difference and a rated transformation ratio of the electromagnetic voltage transformer under a rated operating condition, an effective value of an input voltage of the voltage ratio standarder, and an effective value of a current flowing through an input side of the voltage ratio standarder. The ratio difference compensation module is configured to compensate a predetermined ratio difference compensation amount by adjusting the first precision adjustable resistor to achieve the predetermined ratio difference compensation amount for the ratio difference of the voltage ratio standarder, so that the ratio difference of the voltage ratio standarder is within a ratio difference limit value range required by high accuracy, and the angle difference compensation module is configured to compensate a predetermined angle difference compensation amount by adjusting the second precision adjustable resistor to achieve the predetermined angle difference compensation amount for the angle difference of the voltage ratio standarder, so that the angle difference of the voltage ratio standarder is within an angle difference limit value range required by high accuracy.

2. The high-accuracy voltage ratio standard of claim 1, wherein, The parameters of the ratio difference compensation module include a transformation ratio of the compensation voltage transformer, a transformation ratio of the first auxiliary voltage transformer, and an adjustment fineness of the first precision adjustable resistor.

3. The high-accuracy voltage ratio standard of claim 1, wherein, The parameters of the angle difference compensation module include a transformation ratio of the current transformer, a resistance value of the third precision resistor, and an adjustment fineness of the second precision adjustable resistor.

4. The high-accuracy voltage ratio standard of claim 1, wherein, The parameters of the angle difference compensation module include a resistance value of the fourth precision resistor, a transformation ratio of the second auxiliary voltage transformer, and an adjustment fineness of the second precision adjustable resistor.

5. The high-accuracy voltage ratio standard of claim 1, wherein, The first precision adjustable resistor and the second precision adjustable resistor are both multi-turn adjustable resistors.

6. A method of implementing a high-accuracy voltage ratio standardizer, characterized in that, The method comprises the following steps: S1, obtaining an electromagnetic voltage transformer with an accuracy of at least 1 level and measuring a ratio difference and an angle difference thereof under a rated operating condition; S2, calculating a ratio error compensation amount and an angle error compensation amount to be applied to the electromagnetic voltage transformer based on the ratio error and the angle error of the electromagnetic voltage transformer for realizing the high-accuracy voltage ratio standard device; S3, configuring parameters of a ratio error compensation module according to the ratio error compensation amount and a rated transformation ratio of the electromagnetic voltage transformer and coupling the ratio error compensation module to the electromagnetic voltage transformer, wherein the coupling of the ratio error compensation module to the electromagnetic voltage transformer comprises: coupling a compensation voltage transformer of an in-phase voltage acquisition unit to the electromagnetic voltage transformer, coupling a first auxiliary voltage transformer to the compensation voltage transformer, and coupling a first precision adjustable resistor to the first auxiliary voltage transformer and to a secondary winding of the electromagnetic voltage transformer, the parameters of the ratio error compensation module being configured according to the ratio error compensation amount and the rated transformation ratio of the electromagnetic voltage transformer, wherein the parameters of the ratio error compensation module comprise a transformation ratio of the compensation voltage transformer, a transformation ratio of the first auxiliary voltage transformer, and a resistance value of the first precision adjustable resistor, and the parameters of the ratio error compensation module satisfy the following formula (1): R x = R f * ΔU f * K1*K2 / K0 Equation (1) wherein R x represents the adjusted resistance value of the first precision adjustable resistor, R f represents the nominal maximum resistance value of the first precision adjustable resistor, ΔU f represents the ratio difference compensation amount, K1 represents the transformation ratio of the compensation voltage transformer, K2 represents the transformation ratio of the first auxiliary voltage transformer, and K0 represents the rated transformation ratio of the electromagnetic voltage transformer; S4, configuring parameters of an angle error compensation module according to the angle error compensation amount and a rated transformation ratio of the electromagnetic voltage transformer and coupling the angle error compensation module to the electromagnetic voltage transformer and the ratio error compensation module to form the voltage ratio standard device, wherein the coupling of the angle error compensation module to the electromagnetic voltage transformer and the ratio error compensation module comprises: coupling a quadrature voltage acquisition unit to a primary winding of the electromagnetic voltage transformer, and coupling a second precision adjustable resistor to the quadrature voltage acquisition unit and to a secondary winding of the first auxiliary voltage transformer, wherein the quadrature voltage acquisition unit is composed of a current transformer and a third precision resistor connected to a secondary side of the current transformer, or the quadrature voltage acquisition unit is composed of a fourth precision resistor and a second auxiliary voltage transformer connected to the fourth precision resistor; the parameters of the angle error compensation module being configured according to an angle error and a rated transformation ratio of the electromagnetic voltage transformer under a rated operating condition, an effective value of an input voltage of the voltage ratio standard device, and an effective value of a current flowing through an input side of the voltage ratio standard device; wherein the parameters of the angle error compensation module comprise a transformation ratio of the current transformer, a resistance value of the third precision resistor, and a resistance value of the second precision adjustable resistor, and the parameters of the angle error compensation module satisfy the following formula (2): R Y = R δ *ΔU δ *U1*K3 / (K0*I*R1) Equation (2) wherein R Y represents the adjusted resistance value of the second precision adjustable resistor, R δ represents the nominal maximum resistance value of the second precision adjustable resistor, ΔU δ represents the angular difference compensation amount, U1 represents the effective value of the input voltage of the voltage ratio standardizer, K3 represents the transformation ratio of the current transformer, I represents the effective value of the current on the input side of the voltage ratio standardizer, and R1 represents the resistance value of the third precision resistor. or the parameters of the angle error compensation module comprise a resistance value of the fourth precision resistor, a transformation ratio of the second auxiliary voltage transformer, and a resistance value of the second precision adjustable resistor, and the parameters of the angle error compensation module satisfy the following formula (3): R Y = R δ *ΔU δ *U1*K4 / (K0*I*R2) Equation (3) wherein K4 represents the transformation ratio of the second auxiliary voltage transformer, and R2 represents the resistance value of the fourth precision resistor; S5, measuring the ratio error and the angle error of the voltage ratio standard device under the rated operating condition and verifying the grades of the ratio error and the angle error of the voltage ratio standard device. S6, judging whether the ratio difference or the angle difference of the voltage ratio standarder exceeds the error limit value range of the high accuracy requirement, if not, the calibration is qualified and goes to step S8, otherwise, goes to step S7; S7, if the ratio difference of the voltage ratio standarder exceeds the ratio difference limit value range of the high accuracy requirement, the ratio difference of the voltage ratio standarder is compensated by adjusting the adjusting resistance value of the first precision adjustable resistor, if the angle difference of the voltage ratio standarder exceeds the angle difference limit value range of the high accuracy requirement, the angle difference of the voltage ratio standarder is compensated by adjusting the adjusting resistance value of the second precision adjustable resistor, and then goes to step S5; S8, completing the high accuracy voltage ratio standarder; the ratio difference and the angle difference of the voltage ratio standarder are both within the error limit value range of the high accuracy requirement after compensation.

7. The method of claim 6, wherein, In the step S4, the connection of the quadrature voltage acquisition unit and the primary winding of the electromagnetic voltage transformer includes: connecting the primary side of the current transformer and the primary winding of the electromagnetic voltage transformer in series, connecting the third precision resistor and the secondary side of the current transformer in parallel, and connecting the second precision adjustable resistor and the third precision resistor in parallel and connecting the second precision adjustable resistor and the secondary winding of the first auxiliary voltage transformer.

8. The method of claim 6, wherein, In the step S4, the connection of the quadrature voltage acquisition unit and the primary winding of the electromagnetic voltage transformer includes: connecting the fourth precision resistor and the primary winding of the electromagnetic voltage transformer in series, and connecting the second auxiliary voltage transformer and the fourth precision resistor in parallel.

9. The method of claim 6, wherein, The first precision adjustable resistor and the second precision adjustable resistor are both set as multi-turn adjustable resistors.

10. The method of claim 6, wherein, The accuracy of the voltage ratio standarder realized by the method is not less than 0.02 level.

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