Unbalanced three-phase distribution state estimation using cooperative particle swarm optimization

Unbalanced three-phase state estimation for advanced distribution management system (DMS) in a smart distribution grid is presented in this paper. With the consideration of renewable distributed generation and variable loads, the distribution state estimation (DSE) is investigated. To solve the state estimation optimization problem, the cooperative particle swarm optimization (Co-PSO) algorithm is proposed based on the particle swarm optimization algorithm. The proposed method can estimate variable loads and renewable distributed generation (DG) values efficiently. Experiment is made on the IEEE 123-bus radial distribution case with variable loads and DG units. Test results and the comparisons with other evolutionary optimization algorithms such as original PSO, improved PSO algorithms, genetic algorithm (GA) demonstrate that the proposed Co-PSO is effective for the DSE problems.