LONG-RANGE PLANNING OF POWER DISTRIBUTION-SYSTEMS - PRIMARY NETWORKS

This paper focuses on the expansion planning of power distribution sys tems. An optimization model that simultaneously considers substation l ocation and sizing, primary feeder routing and reconductoring is used to design the expansion plans. The model considers the fixed and varia ble costs for all new elements and also for the existing ones when exp ansion is taken into account. The objective function seeks to minimize the total annualized expansion cost that includes the cost of losses modeled as a quadratic function. An efficient implicit enumeration alg orithm combined with several heuristic procedures allows large expansi on problems to be solved in a very reasonable time using microcomputer s. The radiality constraints are obtained by applying heuristics that deal with the true expansion costs. The voltage drop constraints are c hecked in the final radial solution and corrective actions are perform ed if they are not satisfied.