Device and method for eliminating residual magnetism of transformer core to output constant-voltage variable-frequency voltage

Abstract

The invention discloses a device and method for eliminating residual magnetism of a transformer core to output constant-voltage variable-frequency voltage, which belong to the field of residual magnetism elimination of single-phase power transformer cores. The device comprises a low-voltage direct-current voltage source for providing power supply for a full-bridge inversion unit, and the full-bridge inversion unit. The full-bridge inversion unit comprises a microcontroller used for generating a switching signal I, a switching signal II and a switching signal III and transmitting the switchingsignal I, the switching signal II and the switching signal III to an optocoupler isolation module, the optocoupler isolation module used for conducting photoelectric isolation on the switching signalI and / or the switching signal II and the switching signal III, a switching driving module for driving switching on or switching off of a switching transistor in the full-bridge inversion unit according to the switching signal I, the switching signal II and the switching signal III, and a full-bridge inversion circuit connected with a target transformer, eliminating residual magnetism of the transformer iron core by switching on or switching off the switching transistor, and outputting constant-voltage variable-frequency voltage to the target transformer. The low-frequency low-voltage power supply is adopted for constant-voltage variable-frequency demagnetization, the purpose of residual magnetism elimination on a test site is achieved, and residual magnetism elimination operation is ensured to be safely and reliably completed.

Description

technical field [0001] The invention relates to the field of single-phase power transformer iron core residual magnetism elimination, and more specifically, relates to a device and method for outputting a constant-voltage variable-frequency voltage by eliminating the transformer iron core residual magnetism. Background technique [0002] The power transformer is one of the most important equipment in the power system. When the transformer completes the DC resistance test or quits operation, there will be residual magnetism in the iron core. When the transformer is put into operation, the existence of residual magnetism will aggravate the saturation of the iron core, causing a large inrush current, which seriously affects the safety of the transformer equipment and the power quality of the power grid. Therefore, before the transformer is put into operation, the residual magnetism elimination operation should be carried out. The traditional degaussing method is to connect the...

AI Technical Summary

Problems solved by technology

However, there is a major defect in this method, that is, for large power transformers, the voltage amplitude of the power frequency high-voltage power supply must reach the rated voltage of the transformer. , and pose a safety hazard

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