A Novel Optimal Power Flow for Real-time Application

Under the competitive environments, power companies may calculate optimal power flow (OPF) in many occasions: especially for such real time applications as contingency analysis and congestion management. However, caused by congestions, etc., it is not guaranteed that OPF has the feasible solution in every calculation case. This paper proposes a new optimal power flow calculation model applicable to the infeasible power flow cases. Namely, a concept of virtual generator is introduced to OPF to make it applicable to the infeasible power flow cases. Fuel costs of the virtual generators are set very large compared with those of the real generators. Therefore, a virtual generator generates electricity only when constraint violations must be resolved through its output. Then, if a virtual generator is connected to every node, any congestion is expected to be resolved through hypothetical generators. To demonstrate the method, several numerical examples are shown. Key-Words: Optimal power flow, Virtual generator, Tabu search, Congestion management, Feasible solution