Fast approach for transient stability constrained optimal power flow based on dynamic reduction method

The main challenge to solve the transient stability constrained optimal power flow (TSC-OPF) problem is its huge dimension due to numerous discretised transient variables and constraints. This problem becomes more serious when large power systems are considered. This study presents a fast approach to realise a global TSC-OPF based on dynamic reduction method, which decomposes the power system into several coherent areas and represents the original system by a reduced equivalent system. In this approach, the single transient stability constraint is obtained by simulating the reduced system instead of the full system. The new approach reduces the simulation execution time and thus increases the efficiency of the TSC-OPF. Two case studies indicate that the proposed approach can remarkably reduce the CPU time of the TSC-OPF procedure, compared with the TSC-OPF based on the full-system simulation. The new approach is very practical in solving the TSC-OPF problem in large power systems where numerous machines are coherent.