Coloured Petri nets approach for solving distribution system contingency by considering customer load patterns

Typical customer load patterns, which have been derived by a load survey st udy, are used to determine the daily load profiles of each service section of distribution feeders. The hourly current flows of line switches and dist ribution feeders are solved by three-phase load flow analysis over a daily period. For a distribution contingency such as feeder overload or short cir cuit fault, the artificial intelligent coloured Petri nets with best-first search approaches are then applied to find the optimal switching operation decision. A coloured Petri nets model with inference mechanism is derived f or load transfer among distribution feeders after the overloading feeders h ave been identified or the faulted section has been isolated. To determine the effectiveness of the proposed methodology, a Taipower sample distributi on system, which serves a mixture of customers, is selected to perform the computer simulation. By comparison with the conventional Petri nets, the pr oposed coloured Petri nets can significantly reduce the size of network mod els, and a more effective switching operation plan can be designed by takin g into account the load characteristics of the customers served.