Early electrical substations needed manual adjustment or switching of equipment, and manual data collection for energy consumption, or abnormal events. As complexity of distribution network developed, it became economically worthwhile for automation of substation and their control from strategically attended points to reduce costs of operation and allow easy overall coordination when emergencies arise.
Early efforts aimed to control substations utilized dedicated communication wires usually run alongside the power circuits. Microwave radio, wired remote control circuits, fiber optic cables and power-line carrier have been used for data acquisition and supervisory control of substations. The discovery of microprocessor enhanced number of points which could be monitored and economically controlled. Nowadays, standard communication protocols like IEC 61850, DNP3 and Modbus are employed to enable multiple intelligent electronic gadgets to relay information to one another and to the control centers. Automation of substation using distribution control is an element of smart-grid.