Extra-high voltage DC voltage transformer verification system and use method thereof

Abstract

The invention discloses an extra-high voltage DC voltage transformer calibration system and a use method thereof, and the system comprises an extra-high voltage standard voltage divider, an extra-high voltage DC current generator, and a DC current transformer calibration instrument. The extra-high voltage standard voltage divider, the extra-high voltage direct current generator and the direct current transformer calibrator are integrated on an integrated platform, and voltage and current output by the extra-high voltage direct current generator are adjusted according to a calibrated transformer. The direct current transformer calibrator can measure output signals of a standard transformer and a calibrated transformer at the same time, convert the output signals into measurement output quantities at the same moment, and analyze and process the measurement output quantities. According to the invention, the verification work of the extra-high voltage DC voltage transformer can be completed only by connecting the high-voltage line of the verified transformer, the accuracy is high, hoisting construction equipment and test loop wiring do not need to be additionally arranged, and the working efficiency of transportation, construction and recovery is reduced to the greatest extent and the working efficiency is improved on the premise of meeting the requirements of rapidness, safety and reliability of a field test.

Description

Technical Field

[0001] This invention belongs to the field of electrical testing equipment technology, specifically relating to an ultra-high voltage DC voltage transformer calibration system and its usage method. Background Technology

[0002] As a crucial primary component of ultra-high voltage (UHVDC) transmission systems, the reliability and measurement accuracy of DC voltage transformers directly impact the safe and stable operation of the entire system. Therefore, on-site calibration of DC voltage transformers is necessary before commissioning and after operation. Currently, a common calibration method involves a rough test of the polarity and turns ratio of the DC voltage transformer under 10% of its rated voltage. However, this method has a limited voltage range and low accuracy. Therefore, calibration across the entire voltage range is necessary to accurately determine whether the measurement accuracy of the DC voltage transformer meets the requirements. Furthermore, current UHVDC voltage transformer calibration methods involve numerous, bulky, and heavy pieces of equipment, making transportation and on-site disassembly and assembly inconvenient, resulting in a large workload and low efficiency. Summary of the Invention

[0003] To address the technical problems existing in the prior art, the purpose of this invention is to provide an ultra-high voltage DC voltage transformer verification system and its usage method.

[0004] To achieve the above objectives and technical effects, the technical solution adopted by this invention is as follows:

[0005] A UHVDC voltage transformer calibration system includes an UHV standard voltage divider, an UHVDC current generator, and a DC current transformer calibrator. The UHV standard voltage divider, UHVDC current generator, and DC current transformer calibrator are integrated on a single platform. The voltage and current output by the UHVDC current generator are adjusted according to the transformer being calibrated. The DC current transformer calibrator can simultaneously measure the output signals of the standard transformer and the transformer being calibrated, convert them into measured output quantities at the same time, and perform analysis and processing.

[0006] Furthermore, the maximum output voltage of the UHVDC voltage transformer should be no less than 800kV, the rated output current should be no less than 10mA, the output voltage stability should be better than 0.03% / 30s, the ripple coefficient should be no higher than 0.1%, and the continuous working time should be no less than 30min.

[0007] Furthermore, the ultra-high voltage standard voltage divider uses a standard resistor as the measuring body. During the design, adjacent resistor elements with the same absolute value of temperature coefficient and voltage coefficient but opposite signs are selected to minimize the influence of temperature coefficient and voltage coefficient on the resistance value.

[0008] Furthermore, the ultra-high voltage standard voltage divider has a double-layer concentric circle structure, consisting of a measuring resistance layer and a shielding resistance layer from the inside out, with the resistance ratio of the measuring resistance layer to the shielding resistance layer being 1:2.

[0009] Furthermore, the output current stability of the ultra-high voltage direct current generator is better than 2×10⁻⁶. -4 / 2min, Output current accuracy: better than 0.02% × reading + 0.005% × range, Output voltage: DC 5V, Current ripple coefficient: ≤1%.

[0010] Furthermore, the DC current transformer calibrator is a high-precision multi-channel measuring instrument with synchronous measurement function, and has the function of calibrating DC current transformers with analog output and digital output.

[0011] Furthermore, when calibrating an ultra-high voltage DC voltage transformer, the ultra-high voltage DC current generator, the DC current transformer to be calibrated, and the standard DC current transformer form a series circuit. The ultra-high voltage DC current generator outputs a large DC current to the DC current transformer to be calibrated and the standard DC current transformer. The DC current transformer to be calibrated and the standard DC current transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC current transformer to be calibrated and the standard DC current transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

[0012] Furthermore, when calibrating an ultra-high voltage DC voltage transformer, the ultra-high voltage standard voltage divider is used to provide ultra-high voltage to both the DC voltage transformer under test and the standard DC voltage transformer. The DC voltage transformer under test and the standard DC voltage transformer are connected in parallel. The DC voltage transformer under test and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of both the DC voltage transformer under test and the standard DC voltage transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

[0013] This invention also discloses a method for using an ultra-high voltage direct current voltage transformer verification system, comprising the following steps:

[0014] The ultra-high voltage standard voltage divider, ultra-high voltage DC current generator and DC current transformer calibrator are integrated into an integrated platform;

[0015] The UHVDC current generator, the DC current transformer to be tested, and the standard DC current transformer are connected in series. The DC current transformer to be tested and the standard DC current transformer are respectively connected to the DC current transformer calibrator. The UHVDC current generator outputs a large DC current to the DC current transformer to be tested and the standard DC current transformer. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC current transformer to be tested and the standard DC current transformer and converts them into the measured output quantity at the same time. Error calculation and result judgment are performed to complete the calibration of the UHVDC voltage transformer.

[0016] When the DC voltage transformer under test and the standard DC voltage transformer are connected in parallel, an ultra-high voltage standard voltage divider provides ultra-high voltage to both the DC voltage transformer under test and the standard DC voltage transformer. The DC voltage transformer under test and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC voltage transformer under test and the standard DC voltage transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention discloses an ultra-high voltage (UHVDC) voltage transformer calibration system and its usage method. The system includes an UHV standard voltage divider, an UHVDC current generator, and a DC current transformer calibrator. These components are integrated onto a single platform. The voltage and current output by the UHVDC current generator are adjusted according to the transformer being calibrated. The DC current transformer calibrator can simultaneously measure the output signals of both the standard transformer and the transformer being calibrated, converting them into simultaneous measured output quantities for analysis and processing. The UHVDC voltage transformer calibration system and its usage method provided by this invention only require connecting the high-voltage line of the transformer being calibrated on-site to complete the calibration work. It offers high accuracy and eliminates the need for additional lifting and setup equipment and test circuit wiring. While ensuring rapid, safe, and reliable on-site testing, it minimizes the workload of transportation, setup, and recovery, thereby improving work efficiency. Detailed Implementation

[0019] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0020] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0021] On one hand, this invention discloses an ultra-high voltage DC voltage transformer calibration system, including an ultra-high voltage standard voltage divider, an ultra-high voltage DC current generator, and a DC current transformer calibrator. The ultra-high voltage standard voltage divider, ultra-high voltage DC current generator, and DC current transformer calibrator are integrated on a single platform. The output current stability of the ultra-high voltage DC current generator is better than 2×10⁻⁶. -4 / 2min, output current accuracy: better than 0.02%×reading+0.005%×range, output voltage: DC 5V, current ripple coefficient: ≤1% (I≥10%). The voltage and current output of the UHVDC current generator can be adjusted according to the current transformer being calibrated. The DC current transformer calibrator is a high-precision multi-channel measuring instrument with synchronous measurement function. It has the function of calibrating DC current transformers with analog output and digital output. The DC current transformer calibrator can simultaneously measure the output signals of the standard current transformer and the current transformer being calibrated and convert them into the measured output quantity at the same time and perform analysis and processing to complete the calibration work.

[0022] The maximum output voltage of the UHVDC voltage transformer should be no less than 800kV, the rated output current should be no less than 10mA, the output voltage stability should be better than 0.03% / 30s, the ripple coefficient should be no higher than 0.1%, and the continuous working time should be no less than 30min.

[0023] The UHV standard voltage divider uses a standard resistor as the measuring element. During design, adjacent resistors with the same absolute value of temperature coefficient and voltage coefficient but opposite signs are selected to minimize the influence of these factors on the resistance value. To reduce the impact of leakage current and corona current on measurement accuracy under high voltage, the UHV standard voltage divider is designed with a double-layer concentric circle structure. From the inside out, there is a measuring resistor layer and a shielding resistor layer, with a resistance ratio of 1:2. The equipotential shielding effect of the shielding resistor layer on the voltage divider resistor layer makes the transverse electric field component near the voltage divider resistor layer close to zero. The near-zero transverse electric field component and the uniformly distributed longitudinal electric field component combine to form a uniformly distributed resultant electric field.

[0024] In this invention, when an ultra-high voltage direct current generator, a DC current transformer to be calibrated, and a standard DC current transformer are connected in series, the ultra-high voltage direct current generator outputs a large DC current to both the DC current transformer to be calibrated and the standard DC current transformer. The DC current transformer to be calibrated and the standard DC current transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of both the DC current transformer to be calibrated and the standard DC current transformer, converts them into measured output quantities at the same time, performs error calculation and result judgment, and thus completes the ultra-high voltage direct current test. The verification of UHV DC voltage transformers involves the following steps: When the DC voltage transformer to be verified and a standard DC voltage transformer are connected in parallel, an UHV standard voltage divider provides UHV to both the DC voltage transformer to be verified and the standard DC voltage transformer. The DC voltage transformer to be verified and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC voltage transformer to be verified and the signals are converted into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the verification of the UHV DC voltage transformer.

[0025] On the other hand, the present invention also discloses a method for using an ultra-high voltage DC voltage transformer verification system, comprising the following steps:

[0026] The ultra-high voltage standard voltage divider, ultra-high voltage DC current generator and DC current transformer calibrator are integrated into an integrated platform;

[0027] The UHVDC current generator, the DC current transformer to be tested, and the standard DC current transformer are connected in series. The DC current transformer to be tested and the standard DC current transformer are respectively connected to the DC current transformer calibrator. The UHVDC current generator outputs a large DC current to the DC current transformer to be tested and the standard DC current transformer. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC current transformer to be tested and the standard DC current transformer and converts them into the measured output quantity at the same time. Error calculation and result judgment are performed to complete the calibration of the UHVDC voltage transformer.

[0028] When the DC voltage transformer under test and the standard DC voltage transformer are connected in parallel, an ultra-high voltage standard voltage divider provides ultra-high voltage to both the DC voltage transformer under test and the standard DC voltage transformer. The DC voltage transformer under test and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC voltage transformer under test and the standard DC voltage transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

[0029] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0030] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A verification system for ultra-high voltage direct current voltage transformers, characterized in that, The system includes an ultra-high voltage standard voltage divider, an ultra-high voltage DC current generator, and a DC current transformer calibrator. These components are integrated on a single platform. The voltage and current output of the ultra-high voltage DC current generator are adjusted according to the transformer being calibrated. The DC current transformer calibrator can simultaneously measure the output signals of both the standard transformer and the transformer being calibrated, convert them into simultaneous measured output quantities, and perform analysis and processing.

2. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, The maximum output voltage of the UHVDC voltage transformer should be no less than 800kV, the rated output current should be no less than 10mA, the output voltage stability should be better than 0.03% / 30s, the ripple coefficient should be no higher than 0.1%, and the continuous working time should be no less than 30min.

3. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, The ultra-high voltage standard voltage divider uses a standard resistor as the measuring body. During the design, adjacent resistor elements with the same absolute value of temperature coefficient and voltage coefficient but opposite signs are selected to minimize the influence of temperature coefficient and voltage coefficient on the resistance value.

4. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, The ultra-high voltage standard voltage divider has a double-layer concentric circle structure, consisting of a measuring resistance layer and a shielding resistance layer from the inside out. The ratio of the resistance values ​​of the measuring resistance layer and the shielding resistance layer is 1:

2.

5. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, The output current stability of the ultra-high voltage direct current generator is better than 2×10⁻⁶. -4 / 2min, Output current accuracy: better than 0.02% × reading + 0.005% × range, Output voltage: DC 5V, Current ripple coefficient: ≤1%.

6. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, The DC current transformer calibrator is a high-precision multi-channel measuring instrument with synchronous measurement function, and has the function of calibrating DC current transformers with analog output and digital output.

7. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, When calibrating an ultra-high voltage DC voltage transformer, the ultra-high voltage DC current generator, the DC current transformer to be calibrated, and the standard DC current transformer form a series circuit. The ultra-high voltage DC current generator outputs a large DC current to the DC current transformer to be calibrated and the standard DC current transformer. The DC current transformer to be calibrated and the standard DC current transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC current transformer to be calibrated and the standard DC current transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

8. The ultra-high voltage DC voltage transformer verification system according to claim 1, characterized in that, When calibrating an ultra-high voltage DC voltage transformer, the ultra-high voltage standard voltage divider is used to provide ultra-high voltage to both the DC voltage transformer under test and the standard DC voltage transformer. The DC voltage transformer under test and the standard DC voltage transformer are connected in parallel. The DC voltage transformer under test and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC voltage transformer under test and the standard DC voltage transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.

9. A method for using an ultra-high voltage direct current voltage transformer verification system, characterized in that, Includes the following steps: The ultra-high voltage standard voltage divider, ultra-high voltage DC current generator and DC current transformer calibrator are integrated into an integrated platform; The UHVDC current generator, the DC current transformer to be tested, and the standard DC current transformer are connected in series. The DC current transformer to be tested and the standard DC current transformer are respectively connected to the DC current transformer calibrator. The UHVDC current generator outputs a large DC current to the DC current transformer to be tested and the standard DC current transformer. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC current transformer to be tested and the standard DC current transformer and converts them into the measured output quantity at the same time. Error calculation and result judgment are performed to complete the calibration of the UHVDC voltage transformer. When the DC voltage transformer under test and the standard DC voltage transformer are connected in parallel, an ultra-high voltage standard voltage divider provides ultra-high voltage to both the DC voltage transformer under test and the standard DC voltage transformer. The DC voltage transformer under test and the standard DC voltage transformer are respectively connected to a DC current transformer calibrator. The DC current transformer calibrator simultaneously measures the secondary low-voltage output signals of the DC voltage transformer under test and the standard DC voltage transformer and converts them into measured output quantities at the same time. Error calculation and result judgment are then performed to complete the calibration of the ultra-high voltage DC voltage transformer.