Investigations on Recloser Operation Negative Effect for Its DownstreamTransformer

This paper investigates negative effect of recloser operation in power transformers. Reclosers are widely used in distribution networks to interrupt transient faults. This instrument interrupts momentary faults by opening and closing its faulty downstream power system. This mechanism causes abrupt change in transformer’s bus voltage magnitude. Changes in transformer bus voltage can cause transformer saturation and inrush current. In this paper raising transformer flux due to fault occurrence and recloser operation is formulized. Next, transformer saturation is analyzed based on fault instance and recloser operation times. Then, the presented analysis is verified, using simulations, and the worst / best recloser operation time is shown. These investigations give insight into the recloser operation consequences. Moreover, the highest peak of inrush current can be obtained, using the proposed flux formulas based on fault instance and recloser operation time.

This paper investigates negative effect of recloser operation in power transformers. Reclosers are widely used in distribution networks to interrupt transient faults. This instrument interrupts momentary faults by opening and closing its faulty downstream power system. This mechanism causes abrupt change in transformer’s bus voltage magnitude. Changes in transformer bus voltage can cause transformer saturation and inrush current. In this paper raising transformer flux due to fault occurrence and recloser operation is formulized. Next, transformer saturation is analyzed based on fault instance and recloser operation times. Then, the presented analysis is verified, using simulations, and the worst / best recloser operation time is shown. These investigations give insight into the recloser operation consequences. Moreover, the highest peak of inrush current can be obtained, using the proposed flux formulas based on fault instance and recloser operation time.