New mitigation method and analysis of the secondary arc current in half-wavelength transmission lines

Abstract

In this work we propose a new mitigation method to minimize secondary arc current and analyze the behavior of electrical quantities related to the single-phase auto reclosing in half-wavelength (HWL) transmission lines. Initially, such quantities are presented for a half-wavelength line without any device that minimizes the secondary arc current. Following, an innovative new secondary arc current mitigation procedure is presented and implemented. The mitigation method proposed in this work is implemented through the insertion of a circuit-breaker in both transformers neutrals at the transmission line terminals, with the intention of isolating the transformers during fault secondary. Our results show that the behavior of electrical quantities related to the single-phase reclosing switching in such very long line is very different when compared with conventional lines. Their values get close to conventional lines when the proposed mitigation technique is implemented. Furthermore, with the proposed solution the secondary arc has a high probability of self-extinguishing during regular dead-time, allowing the application of the single-phase auto-reclosing switching in HWL. The simulations were implemented in a real time digital simulator.