Composite power system reliability assessment using maximum capacity flow and directed Binary Particle Swarm Optimization

This work introduces a new technique to reduce the search space in evaluating reliability indices of power systems. A new formulation for maximum capacity flow of the transmission lines was developed and used in truncating the state space to identify the definite success and definite failure subspaces. A new algorithm based on “directed” Binary Particle Swarm Optimization (BPSO) was developed to search for the designated success or failure states in the remaining part of the state space. The remaining subspace is system dependent, and in case of systems with high capacity and reliability transmission lines in comparison with generation and loading levels, the effect of this subspace on system reliability can be ignored without causing any significant error. This method is very simple and straight forward, yet it reduces the computational time significantly. The method progresses by calculating the total available power carrying capability at every bus and between buses for every system state. Incidence matrix technique was used in building Line Capacity Matrix (LCM). From the LCM and system state (Generation-Transmission-Load), reliability indices can be calculated. This method was applied on two systems, the IEEE RTS and the modified IEEE RTS and it gave promising results.