Modified particle swarm optimization for unit commitment

A modified particle swarm optimization algorithm for the unit commitment issue is presented.A new kind of coding,pseudo active power coding,in which the up/down variable and the active power variable are fused into one variable,is proposed.Then the time complexity of computing is reduced effectively.The units are classified according to their states in every period. And the states of the units are adjusted dynamically in different periods.The unit commitment is optimized in all periods directly.Mathematical methods and repair methods are used to deal with the constraints.The quality of the swarm is improved.The results of numerical simulation demonstrates that the modified particle swam optimization is efficient and practical.