The 4×6 network: a new power switching scheme

The authors describe a novel power-delivery switching concept, where the basic network has four nodes and six branches (a 4×6 switching network). For larger substations, it has substantial advantages over the traditional double breaker, breaker and one-half, and breaker and one-third: up to 40% fewer breakers, higher reliability, and reduced station area in some cases. For some applications it can provide lower short-circuit levels and bus ampacity ratings through the judicious use of normally open-circuit breakers. The concept is applicable to all types of conventional switchgear, including SF₆ . The 4×6 network is shown to be ideal when a particular user´s conditions, e.g. ambient temperature and load-duration curve are such that it is appropriate to apply a 133% peak overload rating to the main supply transformers