Self-correcting standard voltage transformer for wide frequency domain range metering

Abstract

The invention discloses a self-correcting standard voltage transformer for wide frequency domain range metering. The self-correcting standard voltage transformer comprises an electromagnetic voltage mutual inductance unit, the feedback compensation unit is electrically connected with the electromagnetic voltage mutual inductance unit; the capacitive voltage divider unit and the secondary output unit are connected with the feedback compensation unit; wherein the electromagnetic voltage transformer unit is connected with the capacitive voltage divider unit in parallel. According to the self-correction standard voltage transformer for wide frequency domain range metering, through a design mode of combining a power frequency electromagnetic type unit and a capacitive voltage divider, the electromagnetic type voltage transformer unit is not only used as a standard device for power frequency error verification, but also takes a standard voltage under a power frequency as a basis source for self-correction of the capacitive voltage divider under a wide frequency domain; the secondary output voltage of the capacitive voltage divider is adjusted through the feedback compensation unit, and it is guaranteed that errors of the capacitive voltage divider under different frequencies meet the high-precision requirement.

Description

Technical Field

[0001] The invention relates to the technical field of harmonic transformer measurement, and in particular to a self-correcting standard voltage transformer for wide frequency range measurement. Background Art

[0002] Most of the energy meters in the energy metering device measure energy by collecting the signals of the transformer. Therefore, the accuracy of the current and voltage conversion ratio of the transformer directly determines the accuracy of energy measurement. At the same time, the transformer also provides signals and high-voltage isolation for instruments and relay protection. Therefore, the reliability and stability of the transformer plays a vital role in the safe operation and marketing measurement of the entire power system.

[0003] The State Administration for Market Regulation Announcement No. 48 of 2019 issued the "Announcement of the State Administration for Market Regulation on the Release of the Catalogue of Measuring Instruments Subject to Mandatory Management", which also clarified that measuring instruments with supervision methods of P (type approval) and P+V (type approval + mandatory verification) should apply for type approval or imported measuring instruments type approval.

[0004] At present, with the rapid development of the electric power industry, the continuous access of nonlinear loads such as arc metallurgy, distributed power sources such as wind power and photovoltaic power, and fast-changing loads such as high-speed rail, and the access of a large number of rectifier equipment to the power grid have greatly increased the harmonic and interharmonic content of the power system. Under harmonic conditions, winding leakage reactance, distributed capacitance, hysteresis loss and eddy current loss of the iron core under high-frequency conditions will reduce the measurement accuracy of electromagnetic power transformers. In the transmission scenarios of new energy grid connection and high power electronic loads, the power metering device is very likely to produce measurement errors under the influence of wide-frequency harmonics, affecting the fairness of power trading. Therefore, it is urgent to establish a wide-frequency voltage transformer standard device to achieve high-accuracy measurement of power voltage transformers under power frequency and 2nd to 50th harmonics, and to ensure the measurement accuracy and safe and stable operation of the new power system. Summary of the invention

[0005] In view of the problems existing in the above-mentioned existing self-correcting standard voltage transformer for wide frequency range measurement, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a self-correcting standard voltage transformer for wide frequency range measurement, which is used for error verification of power voltage transformer in the power frequency harmonic domain.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0008] Electromagnetic voltage transformer unit;

[0009] a feedback compensation unit electrically connected to the electromagnetic voltage mutual inductance unit; and

[0010] a capacitive voltage divider unit and a secondary output unit connected to the feedback compensation unit;

[0011] Wherein, the electromagnetic voltage transformer unit is connected in parallel with the capacitive voltage divider unit.

[0012] As a preferred solution of the self-correcting wide-frequency range metering standard voltage transformer of the present invention, the electromagnetic voltage transformer unit includes:

[0013] A primary winding, wherein the primary winding is AN;

[0014] two secondary windings, the secondary windings comprising a first secondary winding and a second secondary winding;

[0015] The first secondary windings are 1a-1n, and the second secondary windings are 2a-2n.

[0016] As a preferred solution of the self-correcting wide-frequency range metering standard voltage transformer of the present invention, the capacitive voltage divider unit adopts the capacitive voltage division principle, specifically,

[0017] The upper bridge arm capacitor C1 and the lower bridge arm capacitor C2, C1 and C2 are connected in series, the input voltage of the capacitive voltage divider is U1, the output windings 3a-3n are drawn out from both ends of the lower bridge arm C2, and the primary output voltage signal U2 of the output voltage divider of the output windings 3a-3n.

[0018] As a preferred solution of the self-correcting standard voltage transformer for wide frequency range measurement of the present invention, wherein: the feedback compensation unit is composed of a signal conditioning module, an A / D sampling module, an analysis and processing module, an MCU and a voltage division compensation module;

[0019] The signal conditioning module is connected to the A / D sampling module, the A / D sampling module is connected to the signal analysis and processing module, the signal analysis and processing module is connected to the MCU, and the MCU is connected to the voltage division compensation module;

[0020] The signal conditioning module is connected to the second secondary winding 2a-2n of the electromagnetic voltage transformer unit, and is used to collect the working voltage and voltage frequency signals of the electromagnetic voltage transformer unit, and then convert the collected signals into digital-to-analog signals through the A / D sampling module, and then analyze and process them through the signal analysis and processing module, and finally calculate them through the MCU.

[0021] As a preferred solution of the self-correcting standard voltage transformer for wide frequency range measurement described in the present invention, wherein: the MUC is connected to the secondary winding 3a-3n of the capacitor voltage divider unit, and the MCU adjusts the secondary output voltage U2 of the capacitor voltage divider unit through the MCU program-controlled output voltage compensation coefficient based on the U2 signal input by the capacitor voltage divider unit 3a-3n and the working voltage amplitude and frequency signal of the electromagnetic voltage transformer unit.

[0022] As a preferred solution of the self-correcting standard voltage transformer for wide frequency range measurement of the present invention, wherein: the MCU has built-in correction curves of voltage, frequency and voltage division ratio of the capacitive voltage divider unit and voltage compensation coefficient;

[0023] By collecting the current working voltage and frequency values ​​and controlling the voltage divider compensation module, the primary output voltage signal U2 of the capacitive voltage divider unit is adjusted to achieve the final signal output of the capacitive voltage divider unit, and the output signal is U3.

[0024] As a preferred solution of the self-correcting standard voltage transformer for wide-frequency range measurement described in the present invention, the voltage division compensation module is a resistor voltage division, and the voltage division reference ratio is 1 / 10. The lower bridge wall resistance R2 is adjusted by selecting the switch to input the resistor to change the voltage division ratio.

[0025] As a preferred solution of the self-correcting wide-frequency range metering standard voltage transformer of the present invention, wherein: the voltage division compensation module includes an upper bridge arm resistor string R1, a lower bridge arm resistor string R2, and a first compensation resistor string R10, R20, R30, R40, and a second compensation resistor string R00, R01, R02, R03;

[0026] The voltage division compensation module further includes a first compensation switch group K10, K20, K30, K40 and a second compensation switch group K00, K01, K02, K03;

[0027] Among them, the first compensation switch group K10, K20, K30, K40 switches are sequentially connected in parallel with the first compensation resistor string R10, R20, R30, R40 resistors to realize the switching control of each resistor of the first compensation resistor string, and the second compensation switch group K00, K01, K02, K03 switches are sequentially connected in parallel with the second compensation resistor string R00, R01, R02, R03 resistors to realize the switching control of each resistor of the second compensation resistor string;

[0028] The input voltage of the voltage-dividing compensation module is U2, the output voltage of the voltage-dividing compensation module is U3, the upper bridge arm resistor string R1, the lower bridge arm resistor string R2 and the second compensation resistor string R00, R01, R02, R03 of the voltage-dividing compensation module are connected in series, and the lower bridge arm resistor string R2 is connected in parallel with the first compensation resistor string R10, R20, R30, R40;

[0029] The first end of the upper bridge arm resistor string R1 is connected to the output winding 3a-3n of the capacitive voltage divider unit to ground, and the voltage U2 is applied to the upper and lower bridge arms of the voltage division compensation module;

[0030] The first end of the lower bridge arm resistor string R2 and the end of the second compensation resistor string R03 lead to output windings 4a-4n to achieve compensated voltage output, and the output voltage is U3.

[0031] As a preferred solution of the self-correcting wide-frequency range metering standard voltage transformer of the present invention, wherein: the upper bridge arm resistance R1 = 90kΩ, the lower bridge arm resistance R2 = 10kΩ; the output voltage is,

[0032]

[0033] By connecting the lower bridge arm resistor in series with R2 in parallel, the output voltage becomes smaller and the transformation ratio of the capacitor voltage divider becomes larger.

[0034] As a preferred solution of the self-correcting wide-frequency range metering standard voltage transformer of the present invention, the feedback compensation device is composed of signal conditioning, A / D sampling, analysis and processing, MCU and voltage division compensation module, and measures the voltage and frequency of the electromagnetic standard voltage transformer unit by collecting the secondary signal;

[0035] The MCU is used to control the switch of the voltage divider compensation module to adjust the voltage divider of the secondary signal U2 of the capacitor voltage divider.

[0036] The beneficial effects of the present invention are as follows: through the design method of combining the power frequency electromagnetic unit with the capacitor voltage divider, the electromagnetic voltage transformer unit is not only used as a standard for power frequency error calibration, but also uses the standard voltage under power frequency as the basis source for self-correction of the capacitor voltage divider under wide frequency domain, and adjusts the secondary output voltage of the capacitor voltage divider through the feedback compensation unit to ensure that the error of the capacitor voltage divider under different frequencies meets the high-precision requirements, and is used as a standard for error calibration under wide frequency domain. The present invention makes full use of the advantages of high power frequency precision of the electromagnetic principle voltage transformer and the advantages of good linearity of the capacitor voltage divider, and forms a standard that meets the requirements for harmonic voltage transformer calibration, realizing wide-frequency error calibration of power voltage transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0038] Figure 1 This is a schematic diagram of the self-correcting standard voltage transformer for wide frequency range measurement according to the present invention.

[0039] Figure 2 The schematic diagram of the feedback compensation unit of the self-correcting standard voltage transformer for wide frequency range measurement of the present invention is shown.

[0040] Figure 3 The diagram is a schematic diagram of the voltage division compensation principle of the self-correcting standard voltage transformer for wide frequency range measurement of the present invention.

[0041] Figure 4 The self-correction software flow chart of the self-correction standard voltage transformer for wide frequency range measurement of the present invention. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0045] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0046] Example 1

[0047] Reference Figure 1 to Figure 3, which is the first embodiment of the present invention, provides a self-correcting standard voltage transformer for wide frequency range measurement, the device comprising:

[0048] Electromagnetic voltage transformer unit;

[0049] a feedback compensation unit electrically connected to the electromagnetic voltage mutual inductance unit; and

[0050] a capacitive voltage divider unit and a secondary output unit connected to the feedback compensation unit;

[0051] Wherein, the electromagnetic voltage transformer unit is connected in parallel with the capacitive voltage divider unit.

[0052] It also has the requirements of 0.02 level at 50Hz power frequency and 0.2 level at 2-50 harmonics, and can be used for power frequency and 2-50 harmonic error measurement of harmonic power voltage transformers of level 0.1 and below. The voltage level of the self-correcting wide-band measurement standard voltage transformer covers 10kV-220kV, and other non-standard voltage levels can also be implemented by reference.

[0053] The electromagnetic voltage mutual inductance unit comprises:

[0054] A primary winding, wherein the primary winding is AN;

[0055] two secondary windings, the secondary windings comprising a first secondary winding and a second secondary winding;

[0056] The first secondary windings are 1a-1n, and the second secondary windings are 2a-2n.

[0057] The accuracy of the secondary winding at power frequency is 0.02;

[0058] The first secondary winding 1a-1n is used for measurement, and is connected to the test error measuring instrument through the secondary output unit to realize the output of the comparison standard signal for error calibration under the working frequency; the second secondary winding 2a-2n is used for measurement, and is connected to the feedback compensation unit to measure the working voltage and frequency of the electromagnetic voltage transformer unit to realize the input of the feedback compensation unit.

[0059] The capacitive voltage divider unit adopts the capacitive voltage division principle, specifically,

[0060] The upper bridge arm capacitor C1 and the lower bridge arm capacitor C2, C1 and C2 are connected in series, the input voltage of the capacitive voltage divider is U1, the output windings 3a-3n are drawn out from both ends of the lower bridge wall C2, and the primary output voltage signal U2 of the output voltage divider of the output windings 3a-3n is:

[0061]

[0062] U2 voltage is 100V.

[0063] The feedback compensation unit is composed of a signal conditioning module, an A / D sampling module, an analysis and processing module, an MCU and a voltage division compensation module;

[0064] The signal conditioning module is connected to the A / D sampling module, the A / D sampling module is connected to the signal analysis and processing module, the signal analysis and processing module is connected to the MCU, and the MCU is connected to the voltage division compensation module;

[0065] The signal conditioning module is connected to the second secondary winding 2a-2n of the electromagnetic voltage transformer unit, and is used to collect the working voltage and voltage frequency signals of the electromagnetic voltage transformer unit, and then convert the collected signals into digital-to-analog signals through the A / D sampling module, and then analyze and process them through the signal analysis and processing module, and finally calculate them through the MCU.

[0066] The MUC is connected to the secondary winding 3a-3n of the capacitor voltage divider unit. The MCU adjusts the secondary output voltage U2 of the capacitor voltage divider unit through the MCU program-controlled output voltage compensation coefficient based on the U2 signal input by the capacitor voltage divider unit 3a-3n and the working voltage amplitude and frequency signal of the electromagnetic voltage transformer unit, so that its voltage division ratio meets the 0.2 level requirement in different frequency bands.

[0067] The MCU has built-in correction curves for the voltage, frequency and voltage division ratio of the capacitive voltage divider unit and a voltage compensation coefficient;

[0068] By collecting the current working voltage and frequency values ​​and controlling the voltage divider compensation module, the primary output voltage signal U2 of the capacitive voltage divider unit is adjusted to achieve the final signal output of the capacitive voltage divider unit, and the output signal is U3.

[0069] The voltage divider compensation module is a resistor voltage divider with a voltage divider reference ratio of 1 / 10. By selecting the switch to input the resistor, the lower bridge wall resistor R2 is adjusted to change the voltage divider ratio, so that the final voltage divider ratio of the capacitor voltage divider unit is U1 / U3, and the accuracy meets the 0.2 level accuracy within a wide frequency range.

[0070] The voltage division compensation module includes an upper bridge arm resistor string R1, a lower bridge arm resistor string R2, a first compensation resistor string R10, R20, R30, R40, and a second compensation resistor string R00, R01, R02, R03;

[0071] The voltage division compensation module further includes a first compensation switch group K10, K20, K30, K40 and a second compensation switch group K00, K01, K02, K03;

[0072] Among them, the first compensation switch group K10, K20, K30, K40 switches are sequentially connected in parallel with the first compensation resistor string R10, R20, R30, R40 resistors to realize the switching control of each resistor of the first compensation resistor string, and the second compensation switch group K00, K01, K02, K03 switches are sequentially connected in parallel with the second compensation resistor string R00, R01, R02, R03 resistors to realize the switching control of each resistor of the second compensation resistor string;

[0073] The input voltage of the voltage-dividing compensation module is U2, the output voltage of the voltage-dividing compensation module is U3, the upper bridge arm resistor string R1, the lower bridge arm resistor string R2 and the second compensation resistor string R00, R01, R02, R03 of the voltage-dividing compensation module are connected in series, and the lower bridge arm resistor string R2 is connected in parallel with the first compensation resistor string R10, R20, R30, R40;

[0074] The first end of the upper bridge arm resistor string R1 is connected to the output winding 3a-3n of the capacitive voltage divider unit to ground, and the voltage U2 is applied to the upper and lower bridge arms of the voltage division compensation module;

[0075] The first end of the lower bridge arm resistor string R2 and the end of the second compensation resistor string R03 lead to output windings 4a-4n to achieve compensated voltage output, and the output voltage is U3.

[0076] The upper bridge arm resistor R1 = 90kΩ, the lower bridge arm resistor R2 = 10kΩ; the output voltage is,

[0077]

[0078] The capacitor voltage divider is affected by temperature, humidity, frequency, etc., and the voltage divider ratio is changing. Therefore, the output voltage is adjusted through the resistor voltage divider. The method is to connect R00-R03 in series with R2 or R10-R40 in parallel, and select the program control through the selection switch. By connecting the resistor in series with R2, the output voltage becomes larger and the ratio of the capacitor voltage divider becomes smaller. In order to ensure sufficient adjustment fineness such as 0.05%, select R00 = 5Ω. In order to adjust the step width wider, the doubling method is adopted, R01 = 10Ω (change 0.1%), R02 = 20Ω (change 0.2%), R03 = 40Ω (change 0.4%). In this way, through single selection or multiple selection, 0.05%-0.75% change can be achieved, and the adjustment fineness is 0.05%;

[0079] By connecting the lower bridge arm resistor in series with the parallel resistor R2, the output voltage becomes smaller and the ratio of the capacitor voltage divider becomes larger. In order to ensure sufficient adjustment fineness, such as 0.05%, R10 = 20MΩ is selected. In order to adjust the step width wider, the doubling method is adopted, R20 = 20MΩ (change 0.1%), R30 = 10MΩ (change 0.2%), R40 = 5MΩ (change 0.4%). In this way, by single selection or multiple selection, a change of 0.05%-0.75% can be achieved, and the adjustment fineness is 0.05%;

[0080] To ensure stability, the resistors used shall have an accuracy of not less than 0.05%, a rated power of not less than 0.25W, and a temperature drift of less than 5ppm.

[0081] The feedback compensation device consists of signal conditioning, A / D sampling, analysis and processing, MCU and voltage division compensation module. It collects the secondary signal of the electromagnetic standard voltage transformer unit and measures its voltage and frequency.

[0082] The MCU is used to control the switch of the voltage divider compensation module to adjust the voltage divider of the secondary signal U2 of the capacitor voltage divider.

[0083] Example 2

[0084] Reference Figure 4 , which is the second embodiment of the present invention, and this embodiment is different from the first embodiment in that: it is a self-correcting software process of a standard voltage transformer for self-correcting wide frequency domain measurement.

[0085] Compared with Example 1, further, the self-correction method process includes:

[0086] S1, 50Hz, voltage 10%-120% rated voltage (record a value every 10%), compare with the external standard voltage transformer, and record the voltage divider ratio curve relationship of the capacitor voltage divider unit; then at 100Hz, 150Hz, 200Hz, ... 2500Hz, voltage 10%-120% rated voltage (record a value every 10%), compare with the external standard voltage transformer, and draw the voltage divider ratio curve relationship of the capacitor voltage divider unit in different frequency bands.

[0087] S2. The voltage and frequency of the secondary terminals 2a2n are measured through the feedback compensation unit. According to the frequency and voltage divider ratio curve of the capacitive voltage divider unit in (1), the current real voltage divider ratio is calculated, and the voltage adjustment ratio required to adjust the voltage divider ratio to meet the 0.2 level is calculated.

[0088] S3, the program-controlled voltage-dividing compensation module proportionally adjusts the secondary output voltage U2 of the capacitive voltage divider unit so that the overall voltage-dividing ratio of the capacitive voltage divider unit meets the accuracy requirement.

[0089] S4, completes self-correction and can be used for error correction in a wide frequency domain.

[0090] The remaining structures are the same as those of Example 1.

[0091] Combined with Figures 1 to 4 As shown, the present invention adopts a design method of combining an industrial frequency electromagnetic unit with a capacitor voltage divider. The electromagnetic voltage transformer unit is not only used as a standard for industrial frequency error calibration, but also uses the standard voltage under industrial frequency as a basis source for self-correction of the capacitor voltage divider under a wide frequency domain. The secondary output voltage of the capacitor voltage divider is adjusted by a feedback compensation unit to ensure that the error of the capacitor voltage divider under different frequencies meets the high-precision requirements, and is used as a standard for error calibration under a wide frequency domain. The present invention makes full use of the advantages of the high industrial frequency precision of the electromagnetic principle voltage transformer and the good linearity of the capacitor voltage divider to form a standard that meets the requirements for harmonic voltage transformer calibration, and realizes the wide-frequency error calibration of the power voltage transformer.

[0092] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0093] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A self-correcting standard voltage transformer for wide frequency range measurement, characterized in that: include, Electromagnetic voltage transformer unit; A feedback compensation unit electrically connected to the electromagnetic voltage mutual inductance unit; as well as, a capacitive voltage divider unit and a secondary output unit connected to the feedback compensation unit; Wherein, the electromagnetic voltage transformer unit is connected in parallel with the capacitive voltage divider unit.

2. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 1, characterized in that: The electromagnetic voltage mutual inductance unit comprises: A primary winding, wherein the primary winding is AN; two secondary windings, the secondary windings comprising a first secondary winding and a second secondary winding; The first secondary windings are 1a-1n, and the second secondary windings are 2a-2n.

3. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 2, characterized in that: The capacitive voltage divider unit adopts the capacitive voltage division principle, specifically, The upper bridge arm capacitor C1 and the lower bridge arm capacitor C2, C1 and C2 are connected in series, the input voltage of the capacitive voltage divider is U1, the output windings 3a-3n are drawn out from both ends of the lower bridge arm C2, and the primary output voltage signal U2 of the output voltage divider of the output windings 3a-3n.

4. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 3 is characterized in that: The feedback compensation unit is composed of a signal conditioning module, an A / D sampling module, an analysis and processing module, an MCU and a voltage division compensation module; The signal conditioning module is connected to the A / D sampling module, the A / D sampling module is connected to the signal analysis and processing module, the signal analysis and processing module is connected to the MCU, and the MCU is connected to the voltage division compensation module; The signal conditioning module is connected to the second secondary winding 2a-2n of the electromagnetic voltage transformer unit, and is used to collect the working voltage and voltage frequency signals of the electromagnetic voltage transformer unit, and then convert the collected signals into digital-to-analog signals through the A / D sampling module, and then analyze and process them through the signal analysis and processing module, and finally calculate them through the MCU.

5. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 4, characterized in that: The MUC is connected to the secondary winding 3a-3n of the capacitor voltage divider unit. The MCU adjusts the secondary output voltage U2 of the capacitor voltage divider unit through the MCU program-controlled output voltage compensation coefficient according to the U2 signal input by the capacitor voltage divider unit 3a-3n and the working voltage amplitude and frequency signal of the electromagnetic voltage transformer unit.

6. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 5, characterized in that: The MCU has built-in correction curves for the voltage, frequency and voltage division ratio of the capacitive voltage divider unit and a voltage compensation coefficient; By collecting the current working voltage and frequency values ​​and controlling the voltage divider compensation module, the primary output voltage signal U2 of the capacitive voltage divider unit is adjusted to achieve the final signal output of the capacitive voltage divider unit, and the output signal is U3.

7. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 6, characterized in that: The voltage division compensation module is a resistor voltage division, and the voltage division reference ratio is 1 / 10. The lower bridge wall resistor R2 is adjusted by selecting the switch to input the resistor to change the voltage division ratio.

8. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 7, characterized in that: The voltage division compensation module includes an upper bridge arm resistor string R1, a lower bridge arm resistor string R2, a first compensation resistor string R10, R20, R30, R40, and a second compensation resistor string R00, R01, R02, R03; The voltage division compensation module also includes a first compensation switch group K10, K20, K30, K40 and a second compensation switch group K00, K01, K02, K03; Among them, the first compensation switch group K10, K20, K30, K40 switches are sequentially connected in parallel with the first compensation resistor string R10, R20, R30, R40 resistors to realize the switching control of each resistor of the first compensation resistor string, and the second compensation switch group K00, K01, K02, K03 switches are sequentially connected in parallel with the second compensation resistor string R00, R01, R02, R03 resistors to realize the switching control of each resistor of the second compensation resistor string; The input voltage of the voltage-dividing compensation module is U2, the output voltage of the voltage-dividing compensation module is U3, the upper bridge arm resistor string R1, the lower bridge arm resistor string R2 and the second compensation resistor string R00, R01, R02, R03 of the voltage-dividing compensation module are connected in series, and the lower bridge arm resistor string R2 is connected in parallel with the first compensation resistor string R10, R20, R30, R40; The first end of the upper bridge arm resistor string R1 is connected to the output winding 3a-3n of the capacitive voltage divider unit to ground, and the voltage U2 is applied to the upper and lower bridge arms of the voltage division compensation module; The first end of the lower bridge arm resistor string R2 and the end of the second compensation resistor string R03 lead to output windings 4a-4n to achieve compensated voltage output, and the output voltage is U3.

9. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 8, characterized in that: The upper bridge arm resistor R1 = 90kΩ, the lower bridge arm resistor R2 = 10kΩ; the output voltage is, By connecting the lower bridge arm resistor in series with R2 in parallel, the output voltage becomes smaller and the transformation ratio of the capacitor voltage divider becomes larger.

10. The self-correcting standard voltage transformer for wide frequency range measurement according to claim 9, characterized in that: The feedback compensation device is composed of signal conditioning, A / D sampling, analysis and processing, MCU and voltage division compensation module, and measures the voltage and frequency of the secondary signal of the electromagnetic standard voltage transformer unit by collecting the secondary signal; The MCU is used to control the switch of the voltage divider compensation module to adjust the voltage divider of the secondary signal U2 of the capacitor voltage divider.

Images