Concept of control system for optimal switching of phase shifting transformers

摘要

Paper presents an innovative concept for automatic selection of an optimal tap of the phase shifting transformer (PST) before its switching-on. The purpose of the system is to enable the switching-on of the PST without sudden changes in power network operating conditions. For the investigation of the underlying phenomena during switching, a test power network containing the accurate dynamic model of the PST was developed. The investigations were performed for different scenarios of changes in the power network parameters and control options of the PST. This allowed determining the desired functionality and structure of the automation system for selecting an optimal tap of the PST before its switching-on. The developed automation system is based on synchronous measurements, and this represents a novel implementation of such measurements. Verification simulation studies indicate that the proposed concept achieves the stated objectives. It is expected that the practical application of this automation system can resolve the transient overcurrent in the adjoining network components arising from PST switching. Overall this will enable significant minimization of negative effects of PST switching-on the power network operating conditions.