A fully shielded high voltage isolated voltage transformer

Abstract

A full-shielding high-voltage isolated-type voltage transformer comprises a tubular secondary low-voltage shielding electrode (1) coaxially mounted in an annular primary high-voltage shielding electrode (2), and flanges fixing the primary high-voltage shielding electrode and the secondary low-voltage shielding electrode respectively. A flange (12) and a flange (23) which fix the primary high-voltage shielding electrode are disposed on the outer side of the primary high-voltage shielding electrode in parallel, axes of a flange (3) and a flange (4) which fix the secondary low-voltage shielding electrode are perpendicularly intersected at the axis of the secondary low-voltage shielding electrode, and both the primary high-voltage shielding electrode and the secondary low-voltage shielding electrode are made of aluminum alloy. For the full-shielding high-voltage isolated-type voltage transformer, accuracy of a voltage transformer is improved, secondary voltages can be superimposed when two single-stage voltage transformers are serially connected, and a voltage series summation method is promoted to perform quantity transmission on higher voltage levels.

Description

Technical field: [0001] The invention relates to a transformer, in particular to a fully shielded high-voltage isolated voltage transformer, which belongs to the technical field of instrument voltage transformers. Background technique: [0002] In my country's power frequency voltage value traceability system, the series addition of voltage transformers is used to trace the value of the voltage ratio. This method directly connects the primary and secondary shielding electrodes of two voltage transformers in series during the operation process. When the potential of each shielding layer changes during the process, it will not affect the error of the voltage transformer; but in fact, due to the imperfect shielding, when the shielding potential changes, the leakage current flows through the excitation winding, which affects the error of the voltage transformer , as the voltage level increases, the impact of capacitive leakage becomes more pronounced. [0003] Judging from the cu...

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Problems solved by technology

[0002] In my country's power frequency voltage value traceability system, the series addition of voltage transformers is used to trace the value of the voltage ratio. This method directly connects the primary and secondary shielding electrodes of two voltage transformers in series during the operation process. When the potential of each shielding layer changes during the process, it will not affect the error of the voltage transformer; but in fact, due to the imperfect shielding, when the shielding potential changes, the leakage current flows through the excitation winding, which affects the error of the voltage transformer , with the increase of voltage level, the influence of capacitive leakage becomes more obvious

[0003] Judging from the current research, it is difficult for standard devices above 220kV voltage level to use voltage series addition to transfer values. Therefore, in order to use voltage series addition to transfer values ​​to higher voltage levels, it is necessary to solve the voltage transformer The problem of secondary voltage series connection, while reducing the impact of the capacitive leakage of the primary and secondary windings on the measurement error

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