The 4 Ã\x97 6 Network: A New Power Switching Scheme

The new power switching scheme, patented in the USA and Canada, overcomes the vulnerability of the traditional double bus systems to faults on or adjacent to either of the main buses. Also, the need for sectionalizing breakers in large stations is eliminated. The basic forms of the network are portrayed in Figure 1 and four (4) triple-connected power nodes A, B, C, & D, formed by the end connections of six (6) branches, each of which contains at least one circuit breaker. The four nodes in the Figure 1 representation are connected by six (6) branches which suggests the name "Four by Six (4 × 6) Network". Figure 1 (a) can be viewed as a four-breaker ring with an added pair of double-crossed single-breaker branches (i.e., the branches cross the ring and also cross each other). Figure 1(b) shows a network which is electrically equivalent to that in Figure 1 (a) but rearranged in a STAR-DELTA representation. Alternatively, Figure 1 (b) can be interpreted as the plan view of a network whose branches are oriented along the outline edges of a tetrahedron. A threedimensional representation of the tetrahedron-configured network, as viewed from face ACD, is portrayed in Figure 1 (c).