Optimal Planning Of Shunt Capacitor Based Reactive Power Compensation For Arborescent Distribution Feeders

Investigation made on optimal planning of shunt capacitor based reactive power compensation for arborescent distribution feeders.An equivalent branch based approach is put forward. An arborescent distribution feeder is transformed into many comb-shaped distribution feeders. The benefit of loss reduction caused by shunt capacitors is used as the index. The optimal planning for each equivalent feeder is performed, respectively. The scheme with the maximum value of objective function is determined as the optimal one. The approach is simple and easy to use, which is suitable for planning of fixed capacitor as well as certain switched capacitor conditions.A step-by-step approach with high efficiency is adopted. The planning of a single capacitor is determined in each step until the managements of all capacitors are reached. It is feasible for optimal allocation and switching-time planning of fixed and switched capacitors under various indexes and restrictions. But it has the possibility to fall into local optimal solution.A capacitor planning oriented neighborhood searching methodology and aspiration criterion are set up, based on which, Tabu search algorithm is introduced to optimize the allocation, capacitance and switching-time of fixed and switched capacitors.It is pointed out that the searching ability of Tabu algorithm is reduced due to the limitation of the Tabu length by the special feature of capacitor planning for a feeder. To solve above problem, an improved Tabu based method with a set of initial solutions determined by step-by-step capacitor planning approach and other application rules is proposed. Consequently, the planning result is further improved. A software is programmed on VC++6.0, on which, the proposed methods are tested, compared and verified showing their feasibility.