CONTROLLED TRANSFORMER ENERGIZATION CONSIDERING RESIDUAL FLUX ― IMPLEMENTATION AND EXPERIMENTAL RESULTS

摘要

Controlled switching has become a valuable means for reduction of transients caused by switching operations in power systems. The theory has been elucidated in various IEEE publications and by the work of CI-GRE during the recent years. In this paper the implementation of closing strategies and the experimental results for controlled energization of an unloaded power delivery transformer are presented. Contrary to present state-of-the-art controllers, the presented controller considers residual fluxes to determine the optimal making instant for the circuit breaker. This allows for the complete elimination of inrush current transients. In comparison with present day controllers, the added consideration of residual fluxes allows further reduction of inrush currents and/or enables one to use less accurate circuit breakers for controlled energization of transformers.