Real-Time Implementation of Controlled Energization of Coupled Power Transformer Using Multi-Stepped PIR, Part-1

A novel concept to minimize the magnitude of inrush during the energization of unloaded power transformers using point-on-wave technique. Point-on-wave switching device (PoWD) and multi-stepped pre-insertion resistor (PIR) are presented in this article. Further, to diminish the consequences of the mechanical operating time scatter (MOTS) of the circuit breaker (CB), a combination of PoWD with a PIR-equipped CB is proposed. This combination is readily available at extra high-voltage substations in the Asia region. In the proposed work, a multi-stepped PIR is proposed to reduce the energy consumed in PIR. The suggested technique has been assessed by precise modelling of the electrically and magnetically coupled power transformer and PIR. At the same time, for optimum results, mathematical analysis has been carried out to determine the energization target of the power transformer. The comparative analysis of the suggested scheme with the existing technology has been carried out which suggests that the proposed technique minimizes the level of inrush and reduces the energy consumed by 65% and 52% during the application of PoW switching technique for energization of the magnetically and electrically connected unloaded power transformers, respectively. Moreover, the obtained results show that the power quality has been improved by large as the second harmonics and dc components of the inrush current are improved by 73.68% and 87.4%, respectively.