Power-frequency single-phase resonant transformer for calibration and boosting of voltage transformer

Abstract

The invention discloses a power-frequency single-phase resonant transformer for onsite calibration and boosting of a voltage transformer. A resonant transformer body (2) and a compensation type adjustable reactor (14) are arranged in a transformer shell (4), a cable package (3) is arranged in the resonant transformer body (2) and comprises a low-voltage winding (10), a medium-voltage compensationwinding (12) and a high-voltage winding (9), and the medium-voltage compensation winding (12) is provided with a medium-voltage tap and is connected with the compensation type adjustable reactor (14)through the medium-voltage tap. Due to connection with the compensation type adjustable reactor through the medium-voltage tap, an inductive component can be introduced, the internal impedance of theresonant transformer can be adjusted to be matched with the capacitance of the tested voltage transformer to form a resonant testing circuit, and the input capacity of the low-voltage winding can be reduced effectively. Moreover, the power-frequency single-phase resonant transformer has the advantages of small size, light weight and good application prospects, and the onsite calibration and boosting of the voltage transformer on a vehicle can be realized.

Description

technical field [0001] The invention relates to a power frequency single-phase resonant transformer used for on-site calibration and step-up of a 500 kV voltage transformer, and belongs to the technical field of high-voltage power transmission and transformation. Background technique [0002] With the deepening of the reform of the power industry system, the accuracy of high-voltage metering devices such as power transformers is directly related to the fairness and rapid development of the power market. For testing, the 500kV voltage transformer is a fixed-installation high-voltage equipment and can only be tested on-site. When calibrating the 500kV voltage transformer, it is necessary to increase the power frequency of the tested voltage transformer to the rated voltage to simulate the tested voltage transformer. The actual operating state of the voltage transformer, so as to compare with the standard voltage transformer to realize the value transfer work of the national st...

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Problems solved by technology

[0002] With the deepening of the reform of the power industry system, the accuracy of high-voltage metering devices such as power transformers is directly related to the fairness and rapid development of the power market. For testing, the 500kV voltage transformer is a fixed-installation high-voltage equipment and can only be tested on-site. When calibrating the 500kV voltage transformer, it is necessary to increase the power frequency of the tested voltage transformer to the rated voltage to simulate the tested voltage transformer. The actual operating state of the voltage transformer, so as to compare with the standard voltage transformer to realize the value transfer work of the national standard. The voltage transformers with a voltage level of 500 kV are mostly capacitive voltage transformers, and their electrical frequency is capacitive. Moreover, the voltage transformer under test cannot be disconnected during the field test, and the entire busbar or GIS pipeline needs to be boosted together, so that the input capacity of the low-voltage winding is added to the ground capacitance, and the additional ground capacitance is the same as the busbar or GIS. It is related to the length of the pipeline, the environment of the test site, the layout of the overhead line, etc. It is an irregular and discrete value, which will affect the detection accuracy of the 500kV voltage transformer

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