Decentralised power system state estimation: a decomposition-coordination approach

The authors address the power system state estimation (PSSE) problem using decomposition-coordination techniques. These techniques are suitable for multi-network power systems. The whole network is divided into geographical areas. Then, for each region, an area-PSSE problem is formulated as a slightly modified weighted least square subproblem. The global optimum of the overall system is obtained by iteratively coordinating the solution of area-PSSE subproblems. Two decomposition-coordination techniques are presented and compared: the first technique is based on Lagrangian relaxation algorithms; and the second is based on augmented Lagrangian relaxation algorithms in combination with the auxiliary principle problem. Within both approaches, reported results confirm the viability of decomposition-coordination techniques in decentralised implementations as applied to PSSE problems. Both approaches are tested on IEEE-based systems