A Solution to Lower Tap Changing or Capacitors Regulator Times in Reactive Power Control in Distribution Systems

In the operation of distribution system, if the tap of transformer and capacitors regulators was frequently changed, these devices would be easily damaged. So it is necessary to lower the tap-changing and capacitors regulators times. The solution algorithm developed for this problem is based on a phase1-phase2 feasible directions approach. A new optimization algorithm, that can obtain the optimal solution of the multi-objective programming problem with consideration of lowering losses and tap changing times or capacitors regulators, is presented. Much attention are paid to lower capacitors regulators times when adjusting the capacitors variables to lower the losses, and changing the taps of transformers to satisfy the voltage constraints in the proposed algorithm. The primary problem is decoupled. Since in fact the capacitors settings have a little impact to the voltage level than transformers, we can first fix the taps of transformers, and adjust the capacitors settings to greatly reduce the probability of voltage limits violations during the decreasing of objective function. Test results are presented for proposed solution scheme; indicate that the method is computationally efficient and the has good convergence characteristics; demonstrate the feasibility of lower taps and capacitors times for both loss reduction and voltage regulation purposes