Shrinking net algorithm and its application in power flow optimization of low-voltage distribution system

Aiming at the three-phase unbalance and multiple distributed sources in low-voltage distribution network, a distribution network optimization model is built, including distributed sources, on-load tap changers, reactive power compensators and plug-in hybrid electric vehicles. A kind of heuristic algorithm, the shrinking net algorithm, is proposed, which condenses gradually the search space inward from the initial boundary population. Its updating iterative formula and calculation steps are given and its convergence is mathematically derived. An improved forward backward sweep algorithm is proposed to effectively deal with the three-phase unbalance and incomplete-phase operation of low-voltage distribution network. The shrinking net algorithm is applied to a test case and IEEE 123-bus system. The optimization results show the proposed algorithm is effective and feasible.