This paper presents a general mathematical model for electrical system control by using the on load tap changers. Any electrical network consists of loops, and most of the loops contains on load tap changer as a control means. These loops are non-homogeneous (X/R not equal constant) which lead to the presence of unbalanced circulating current. These currents cause an additional losses in the network. Using the developed general mathematical model for system control,the power losses in the network are reduced into minimum. This is achieved by determining and injecting an equalizing e.m.f. into the closed loops of the network by changing the power flow in the transmission system using the tap changers. This change in power flow meets the requirements of optimal operation ranges.
