Capacitor Bank Planning for Possible System Contingencies

A new method for planning capacitor banks as sources of VARs for voltage maintenance during anticipated normal and contingency conditions is proposed in this work. The objective is to minimize the total investment cost in the new reactive sources. The scheduling technique is based on sequentialty selecting the most severe operating state which requires the maximum reactive power, determining the optimal bus for this state using a cost-based index, and suitably modifying, if necessary, the reactive power installed to satisfy less severe operating conditions. The solution procedure employs the Compensation method (Large- change Sensitivity Technique) for network solution to update bus voltages. The discrete nature of the capacitor bank, the installation, site, and switching facility cost are all conside ed in-the optimitation process. The algorithm also minimizes the number of switchable installations. The proposed VAR scheduling method is compared with the Inverse Jacobian method for accuracy, and with other scheduling ideas for investment costs, via the IEEE 30-bus system.