Optimal Power Flow in the Smart Distribution Grid Based on the Optimal Load Curtailment and Voltage Stability Index Improvement

Smart grid is the result of enabling consumers in the power system in order to play an effective role in the power system planning and operation processes. The communication, control, and measurement infrastructures create a two-way intelligent communication between users and the network which facilitates the effective implementation of demand response programs (DRPs) such as the direct load control (DLC). In this paper, optimal power flow as an important research topic in the power systems is presented based on DLC and a new voltage stability index. Simple calculations, voltage dependence, indirect dependence to the load and network topology, and also not reducing the network into a two-bus equivalent model, have made the proposed voltage stability index more applicable to real-time calculations considering the load pattern changes. In the proposed method, the optimal load curtailment in some selected loads of the network, with the aim of improving the voltage stability index of the weakest bus is evaluated. Finally, in order to show the effectiveness of the suggested method, it is applied to a 69-bus radial distribution network as an intelligent system