Direct load control for reducing losses in the main and laterals of distribution systems

This paper presents a new approach to minimize power losses and the associated dollar costs in the distribution system. The approach is based on direct load control (DLC) of residential electric water heaters and on increasing the storage capacity of the water heaters under DLC. An optimization algorithm based on the Lagrange multiplier method has been developed to minimize the power system distribution losses. The objective function is obtained by the summation of the system peak real power loss cost, annual energy loss cost, and the cost associated with purchasing and installing the additional water heaters used for DLC. The objective function subject to a number of constraints is solved to obtain the optimal number and location of water heaters under DLC. The proposed method is applied to a main feeder with laterals.