The application and advantages of multi-phase autoreclosing

The autoreclose function contained within protection relays can be applied to various EHV/HV network configurations and provides three main types: single-phase, three-phase and multi-phase. Multi-phase autoreclosing has been applied to double-circuit lines in Japan since the early 1970´s. More recently, the technique has been applied in modern numerical protection relays, such as line differential protection, and has been shown to provide a number of advantages over traditional singleand three phase reclosing methods, when applied to double-circuit lines. This paper describes the introduction and benefits of multiphase autoreclosing, based on transmission fault data and with comparison to other types of autoreclosing.