Segmented compensation composite power supply device for verifying harmonic voltage transformer

Abstract

The invention discloses a segmented compensation composite power supply device for verifying a harmonic voltage transformer, which relates to the field of error verification and metering of power harmonic voltage transformers, and is characterized in that the input end of a power frequency program control voltage regulation power supply is connected with a laboratory power supply, and the output end is connected with a measuring winding of a power frequency all-insulation test transformer; the power frequency all-insulation test transformer is connected with the power frequency multi-gear compensation reactor group; the output end of the broadband voltage regulating power supply is connected with the broadband test transformer; the output end of the broadband test transformer is connected with the power frequency all-insulation test transformer, and the secondary compensation winding is connected with the broadband multi-gear compensation reactor; and the control unit is connected with the power frequency power supply, the broadband power supply and the power frequency and broadband multi-gear compensation reactor. According to the invention, the high-voltage and low-current power frequency test power supply and the low-voltage and large-current harmonic test power supply are superposed to form the composite power supply for error verification of the harmonic voltage transformer, so that the problem that a single power supply needs high voltage and large current and is large in capacity is solved.

Description

Technical Field

[0001] The invention relates to the field of power harmonic voltage transformer error calibration and measurement, in particular to a segmented compensation composite power supply device for harmonic voltage transformer calibration. Background Art

[0002] The power harmonic voltage transformer is based on JJG1177-2021 "Verification Procedure for Harmonic Voltage Transformers". Its metrological performance includes fundamental wave error measurement and fundamental wave superimposed harmonic error measurement. The fundamental frequency is 50Hz or 60Hz, and the harmonic voltages are selected as 3rd, 5th, 7th, 9th, 11th, 12th, 20th, 30th, 40th and 50th respectively. The content rate of each harmonic from the 3rd to the 11th harmonic is 10%, and the content rate of each harmonic of the 12th and above is 5%. It can be seen that the power supply required for calibration needs to be able to achieve an output of 50Hz-3000Hz, covering the frequency output of the power frequency and the highest 50th harmonic, and when the fundamental error is calibrated, the calibration voltage points are 80%, 100% and 120% of the rated voltage of the calibrated transformer. When measuring the fundamental superimposed harmonic error, the fundamental voltage is 100% of the rated voltage of the calibrated voltage transformer, and the harmonic voltage is 10% or 5% of the rated voltage of the calibrated voltage transformer. Taking a 220kV10000pF capacitive voltage transformer as an example, its fundamental voltage must be at least U=220 / √3kV×1.2=152.4kV. When the fundamental is 50Hz, the fundamental current is I=ωCU=2πfCU=2×3.14×50×10000×10 -12 ×152.4×10 3 =0.48A; its harmonic voltage needs to be at least U′=220 / √3kV×0.1=12.7kV. Under 3000Hz harmonic, the current is I′=ωCU=2πfCU=2×3.14×3000×10000×10 -12 ×12.7×10 3 =2.4A; if the power supply is designed in a unified manner, the voltage needs to be at least 152.4kV, the current needs to be at least 2.4A, the minimum capacity is 365.76kVA, and the operating frequency band covers the range of 50Hz-3000Hz. Such a power supply is very heavy in weight, size and cost, and is difficult to design and implement.

[0003] From the above analysis of fundamental voltage and harmonic voltage, it can be seen that the fundamental voltage is high but the current is small, while the harmonic voltage is low but the current is large. Normalized design is not economical and requires a large power capacity, which is generally difficult to meet with the power supply. However, separate design can greatly reduce the design difficulty and cost. Therefore, the fundamental power supply and harmonic power supply can be designed separately, and then superimposed and used to construct a composite power supply to meet the verification needs.

[0004] The above-mentioned 220kV fundamental power supply capacity is about 75kVA, and the harmonic power supply capacity is about 30kVA. In order to reduce the capacity of the voltage regulating power supply and the laboratory power supply, the capacity demand can be reduced through reactive compensation. The compensation methods can be divided into series resonance compensation, parallel resonance compensation, test transformer primary side parallel compensation, secondary side parallel compensation, primary and secondary side mixed compensation and other methods. Through compensation, the power supply capacity can be reduced, which directly reduces the volume, weight and cost of the equipment, and is also more convenient for laboratory work. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is that the fundamental voltage is high but the current is small, the harmonic voltage is low but the current is large, the existing normalized design is not economical and requires a large power capacity, which is generally difficult to meet with the power supply.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a segmented compensation composite power supply device for harmonic voltage transformer calibration, which includes an industrial frequency program-controlled voltage regulating power supply, an industrial frequency full-insulation test transformer, a broadband electronic voltage regulating power supply, a broadband test transformer, an industrial frequency multi-speed combined compensation reactor group, a broadband multi-speed combined compensation reactor group and a control unit; the input end of the industrial frequency program-controlled voltage regulating power supply is connected to a laboratory power supply, and the output end is connected to a measuring winding of the industrial frequency full-insulation test transformer; the compensation winding of the industrial frequency full-insulation test transformer is connected to the industrial frequency multi-speed compensation reactor group; the output end of the broadband voltage regulating power supply is connected to the secondary side metering winding of the broadband test transformer; the output end A′ of the broadband test transformer is connected to the industrial frequency full-insulation test transformer, the X end is connected to the ground, and the secondary compensation winding is connected to the broadband multi-speed compensation reactor; the control unit is connected to the industrial frequency program-controlled voltage regulating power supply, the broadband electronic voltage regulating power supply and the industrial frequency and broadband multi-speed compensation reactors to control the voltage boost, reactor switching, and calculation processing.

[0008] As a preferred solution of a segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, the industrial frequency programmable voltage regulating power supply input is a three-phase 380V, 50Hz industrial frequency power supply, the output is 0-400V single-phase voltage, the output voltage frequency is 50Hz, and the industrial frequency programmable voltage regulating power supply and the industrial frequency fully insulated test transformer constitute an industrial frequency high-voltage test power supply.

[0009] As a preferred solution of a segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, the industrial frequency full-insulation test transformer is designed based on the electromagnetic induction principle, the insulation method is full insulation, the input voltage is 0-400V, the input voltage frequency range is 50Hz, and the output high voltage matches the maximum voltage required for power harmonic voltage transformer calibration.

[0010] As a preferred solution of the segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, the broadband electronic voltage regulating power supply input is a three-phase 380V, 50Hz industrial frequency power supply, the output is a 0-400V single-phase voltage, the output voltage frequency is 150Hz-3000Hz, and the broadband electronic voltage regulating power supply and the broadband test transformer constitute a harmonic high-voltage test power supply.

[0011] As a preferred solution of a segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, wherein: the power frequency multi-speed combined compensation reactor group is used for power frequency full insulation test transformer compensation, reducing the power frequency program-controlled voltage regulating power supply and laboratory power supply capacity, and adopts a power frequency fixed reactor group, which is connected in parallel to the compensation winding dedicated to the power frequency full insulation test transformer, with a total of N groups, and N ≥ 5, the minimum compensation capacity K, and each gear is doubled to 2K, 4K, 8K... (2 N-1 )K, program-controlled switching.

[0012] As a preferred solution of a segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, the wide-band test transformer is designed based on the electromagnetic induction principle, the insulation method is semi-insulation, the input voltage is 0-400V, the input voltage frequency range is 150Hz-3000Hz, and the output high voltage matches the highest harmonic voltage required for power harmonic voltage transformer calibration.

[0013] As a preferred solution of a segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, wherein: the broadband multi-gear combination compensation reactor group is used for broadband test transformer compensation, reducing the capacity of broadband electronic voltage regulating power supply and laboratory power supply, and adopts a broadband fixed reactor group, which is connected in parallel to the compensation winding dedicated to the broadband test transformer, with a total of M groups, and M≥5, the minimum compensation capacity L, and each gear is doubled to 2L, 4L, 8L...(2 M-1 )L, program-controlled switching.

[0014] As a preferred solution of the segmented compensation composite power supply device for harmonic voltage transformer calibration described in the present invention, the control unit is used for output control of industrial frequency and wide-frequency voltage regulating power supply, program-controlled switching of industrial frequency and wide-frequency compensation reactors, and calibration boost control.

[0015] The beneficial effects of the present invention are as follows: the present invention forms a composite power supply for error verification of harmonic voltage transformers by superimposing a high-voltage, low-current industrial frequency test power supply with a low-voltage, high-current harmonic test power supply. Not only can the industrial frequency power supply be used alone to realize the fundamental error verification of the harmonic voltage transformer, but the composite power supply can also be used to realize the fundamental superimposed harmonic error verification of the harmonic voltage transformer. By independently designing and controlling the industrial frequency and broadband power supplies, the problem of large capacity of a single power supply requiring both high voltage and large current is solved, and the problem of 60 times the wide frequency domain working range of the test transformer is solved, so that the working frequency band of the transformer is reduced to 20 times, and the size, weight and design difficulty of the transformer core are greatly reduced; by means of segmented compensation, the industrial frequency power supply and the broadband power supply are separately compensated independently, which not only solves the design difficulty of the broadband operation of the reactor group, but also solves the problem of excessive weight and volume caused by the large single capacity of the reactor group, thereby realizing the miniaturized design and economy of the power supply system. The composite power supply can not only realize the power frequency calibration and boosting of power harmonic voltage transformers, but also can be used for error calibration and boosting of power harmonic voltage transformers under 3-50 harmonics. It also reduces the capacity of the voltage regulating power supply and laboratory power supply, and there is no need to build a separate power supply system, thus reducing the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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:

[0017] Figure 1 This is a structural diagram of a segmented compensation composite power supply device for harmonic voltage transformer calibration in Example 1.

[0018] Figure 2 This is a compensation principle diagram of a segmented compensation composite power supply device for harmonic voltage transformer calibration in Example 2. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] Example 1, reference Figure 1, which is the first embodiment of the present invention, provides a segmented compensation composite power supply device for harmonic voltage transformer calibration, including an industrial frequency programmable voltage regulating power supply, an industrial frequency fully insulated test transformer, a wide-band electronic voltage regulating power supply, a wide-band test transformer, an industrial frequency multi-speed combination compensation reactor group, a wide-band multi-speed combination compensation reactor group and a control unit.

[0022] The input end of the power frequency program-controlled voltage regulating power supply is connected to the laboratory power supply, and the output end is connected to the measuring winding of the power frequency full-insulation test transformer; the compensation winding of the power frequency full-insulation test transformer is connected to the power frequency multi-speed compensation reactor group; the output end of the broadband voltage regulating power supply is connected to the secondary side metering winding of the broadband test transformer; the output end A′ of the broadband test transformer is connected to the power frequency full-insulation test transformer, the X end is connected to the ground, and the secondary compensation winding is connected to the broadband multi-speed compensation reactor; the control unit is connected to the power frequency program-controlled voltage regulating power supply, the broadband electronic voltage regulating power supply, and the power frequency and broadband multi-speed compensation reactors to control the voltage boost, reactor switching, and calculation processing, such as Figure 1 shown.

[0023] The input of the industrial frequency program-controlled voltage-regulating power supply is a three-phase 380V, 50Hz industrial frequency power supply, and the output is a 0-400V single-phase voltage. The output voltage frequency is 50Hz. The industrial frequency program-controlled voltage-regulating power supply and the industrial frequency fully insulated test transformer constitute an industrial frequency high-voltage test power supply.

[0024] The power frequency full insulation test transformer is designed based on the principle of electromagnetic induction. The insulation method is full insulation. The input voltage is 0-400V, the input voltage frequency range is 50Hz, and the output high voltage matches the maximum voltage required for the power harmonic voltage transformer calibration. For example, if the calibration voltage required for a 220kV harmonic voltage transformer is 220 / √3×120%kV, then the power frequency full insulation test transformer output high voltage shall not be less than 220 / √3×120%kV.

[0025] The input of the broadband electronic voltage regulating power supply is a three-phase 380V, 50Hz industrial frequency power supply, the output is a 0-400V single-phase voltage, and the output voltage frequency is 150Hz-3000Hz. The broadband electronic voltage regulating power supply and the broadband test transformer form a harmonic high-voltage test power supply.

[0026] The broadband test transformer is designed based on the principle of electromagnetic induction, with semi-insulation as the insulation method, input voltage of 0-400V, input voltage frequency range of 150Hz-3000Hz, and output high voltage matching the highest harmonic voltage required for power harmonic voltage transformer calibration. For example, if the harmonic voltage required for calibration of 220kV harmonic voltage transformer is 220 / √3×10%kV, then the output high voltage of the power frequency full-insulation test transformer shall not be less than 220 / √3×10%kV.

[0027] The power frequency multi-speed combined compensation reactor group is used for power frequency full insulation test transformer compensation, reducing the power frequency program-controlled voltage regulating power supply and laboratory power supply capacity. It is composed of a power frequency fixed reactor group and connected in parallel to the compensation winding dedicated to the power frequency full insulation test transformer. There are N groups in total, and N ≥ 5. The minimum compensation capacity is K, and each gear is doubled to 2K, 4K, 8K... (2 N-1 )K, program-controlled switching.

[0028] The broadband multi-position combined compensation reactor group is used for broadband test transformer compensation, reducing the capacity of broadband electronic voltage regulating power supply and laboratory power supply. It is composed of broadband fixed reactor groups and connected in parallel to the compensation winding dedicated to the broadband test transformer. There are M groups in total, and M≥5. The minimum compensation capacity is L, and each position is doubled to 2L, 4L, 8L...(2 M-1 )L, program-controlled switching.

[0029] The control unit is used for output control of industrial frequency and wide-frequency voltage regulating power supply, program-controlled switching of industrial frequency and wide-frequency compensation reactors, and verification of boost control.

[0030] The present invention adjusts the power frequency voltage regulating power supply and the broadband electronic voltage regulating power supply respectively by connecting the power frequency full insulation test transformer and the broadband test transformer in series, so that the fundamental power supply and the harmonic power supply are independently output and then compounded and superimposed to meet the voltage boosting needs of the harmonic voltage transformer calibration. The test transformer compensation winding is connected in parallel with a multi-position fixed reactor group to perform compensation, thereby reducing the capacity of the voltage regulating power supply and the laboratory power supply. The required power supply capacity is reduced to only 1 / 5 to 1 / 3 of the maximum test capacity through compensation, which not only reduces the volume and weight of the equipment, but also reduces the equipment cost.

[0031] Through the independent compensation method of industrial frequency and broadband segmentation, the working frequency band of the compensation reactor group is reduced from 60 times the broadband working range to 20 times the broadband working range, making the reactor design simpler, the reactor working efficiency higher, the volume and weight smaller, and the cost lower.

[0032] Example 2, reference Figure 2 , which is the second embodiment of the present invention, and which is different from the first embodiment in that: a segmented compensation composite power supply device for harmonic voltage transformer calibration also includes: Figure 2As shown in the figure, by setting compensation windings on the power frequency full-insulation test transformer and the wide-band test transformer, reactive compensation is achieved by connecting a parallel compensation reactor group to reduce the capacity of the power frequency program-controlled voltage-regulated power supply, the wide-band electronic voltage-regulated power supply and the laboratory power supply. Its advantage is that the voltage of the compensation winding is moderate (generally designed to be 2000V or 2500V), which is higher than the 400V of the test transformer input winding, and is also much lower than the high-voltage output voltage of the test transformer. This voltage insulation design is easy to handle. At the same time, by increasing the voltage and reducing the current, that is, the wire diameter of the reactor wire package, under the same compensation capacity, the reactor will not increase in size due to insulation, and the overall volume and weight will be minimized due to the reduction in wire diameter.

[0033] By connecting multiple-speed reactor groups in parallel, the capacity of each speed increases exponentially by 2, and the least speed is used to achieve the most combinations. For example, when the total compensation capacity is 150kVA, there are 5 groups of compensation, and the compensation capacity of each group is 5kVA, 10kVA, 20kVA, 40kVA, and 80kVA, totaling 155kVA, and the minimum compensation is only 5kVA. The more groups there are, the finer the compensation, and the fewer groups there are, the finer the compensation. A balance needs to be struck between the compensation fineness and the control cost. It is generally recommended to have no less than 5 groups and no less than 15 combinations.

[0034] Through the independent compensation of power frequency and broadband segmentation, the working frequency band of the reactor group is reduced, making the reactor design simpler, and reducing the size and cost. The best compensation is achieved when ω=2πf, and the compensation capacity of the reactor It can be seen from the formula that when the inductance of the reactor is fixed after the design, the compensation capacity decreases with the increase of frequency. As analyzed above, the compensation capacity required under power frequency is large, and the compensation capacity required under harmonics is small. If the integrated compensation of power frequency and harmonics is designed, the compensation reactor group under power frequency can only meet 1 / 60 of the compensation under harmonics; if full compensation is met under harmonics, although the compensation under power frequency can be met, the design working frequency needs to be 50Hz-3000Hz. The iron core wire package of this reactor is large in size, heavy in weight, and high in cost. The segmented independent compensation method is designed according to power frequency and broadband separately. Power frequency compensation only needs to realize power frequency (50Hz or 60Hz) power supply compensation, and broadband compensation only needs to realize harmonic frequency (150Hz-3000Hz) power supply compensation. The working frequency band of the reactor is reduced from 60 times to 20 times, and the volume, size, cost and design difficulty are greatly reduced.

[0035] 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 segmented compensation composite power supply device for harmonic voltage transformer calibration, characterized in that: It includes power frequency program-controlled voltage regulating power supply, power frequency fully insulated test transformer, wide-band electronic voltage regulating power supply, wide-band test transformer, power frequency multi-speed combined compensating reactor group, wide-band multi-speed combined compensating reactor group and control unit; The input end of the industrial frequency program-controlled voltage-regulating power supply is connected to the laboratory power supply, and the output end is connected to the measuring winding of the industrial frequency fully-insulated test transformer; the compensation winding of the industrial frequency fully-insulated test transformer is connected to the industrial frequency multi-speed compensation reactor group; the output end of the broadband voltage-regulating power supply is connected to the secondary side metering winding of the broadband test transformer; the output end A′ of the broadband test transformer is connected to the industrial frequency fully-insulated test transformer, the X end is connected to the ground, and the secondary compensation winding is connected to the broadband multi-speed compensation reactor; the control unit is connected to the industrial frequency program-controlled voltage-regulating power supply, the broadband electronic voltage-regulating power supply, and the industrial frequency and broadband multi-speed compensation reactors to control the voltage boost, reactor switching, and calculation processing.

2. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 1, characterized in that: The industrial frequency program-controlled voltage-regulating power supply input is a three-phase 380V, 50Hz industrial frequency power supply, and the output is a 0-400V single-phase voltage, the output voltage frequency is 50Hz, and the industrial frequency program-controlled voltage-regulating power supply and the industrial frequency fully insulated test transformer constitute an industrial frequency high-voltage test power supply.

3. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 2, characterized in that: The power frequency fully-insulated test transformer is designed based on the principle of electromagnetic induction, has a fully-insulated insulation method, an input voltage of 0-400V, an input voltage frequency range of 50Hz, and an output high voltage that matches the maximum voltage required for power harmonic voltage transformer calibration.

4. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 3, characterized in that: The broadband electronic voltage regulating power supply input is a three-phase 380V, 50Hz industrial frequency power supply, the output is a 0-400V single-phase voltage, the output voltage frequency is 150Hz-3000Hz, and the broadband electronic voltage regulating power supply and the broadband test transformer constitute a harmonic high-voltage test power supply.

5. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 4, characterized in that: The broadband test transformer is designed based on the electromagnetic induction principle, the insulation method is semi-insulation, the input voltage is 0-400V, the input voltage frequency range is 150Hz-3000Hz, and the output high voltage matches the highest harmonic voltage required for power harmonic voltage transformer calibration.

6. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 5, characterized in that: The power frequency multi-speed combined compensation reactor group is used for power frequency full insulation test transformer compensation, reducing the power frequency program-controlled voltage regulating power supply and laboratory power supply capacity. It is composed of a power frequency fixed reactor group and connected in parallel to the compensation winding dedicated to the power frequency full insulation test transformer. There are N groups in total, and N ≥ 5. The minimum compensation capacity is K, and each gear is doubled to 2K, 4K, 8K... (2 N-1 )K, program-controlled switching.

7. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 6, characterized in that: The broadband multi-gear combination compensation reactor group is used for broadband test transformer compensation, reducing the capacity of broadband electronic voltage regulating power supply and laboratory power supply, and is composed of broadband fixed reactor groups, connected in parallel to the compensation winding dedicated to the broadband test transformer, with a total of M groups, and M≥5, the minimum compensation capacity L, and each gear is doubled to 2L, 4L, 8L...(2 M-1 )L, program-controlled switching.

8. A segmented compensation composite power supply device for harmonic voltage transformer calibration as claimed in claim 7, characterized in that: The control unit is used for output control of industrial frequency and wide-frequency voltage regulating power supplies, program-controlled switching of industrial frequency and wide-frequency compensation reactors, and verification of boost control.

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