Security Constrains Unit Commitment by Lagrangian Decomposition and Tabu Search

In partially deregulated power system, a power company encounters such problems as power flow congestions caused by unexpected power wheeling from PPSs (power producer & suppliers) and as to achieve social welfare by optimally operating own generators. These problems can be solved in a lump by solving a security constrained unit commitment problem. This paper proposes a new solution algorithm of the security constrained unit commitment based on Lagrangian decomposition and tabu search. By the Lagrangian decomposition, the problem can be divided into two sub-problems: the unit commitment problem of the time zones and the optimal operation problem of each generator. This paper focuses on tabu search applied to solve the former problem. Some numerical examples are shown to demonstrate the proposed algorithm