Robust Meter Placement for State Estimation in Active Distribution Systems

The active nature of next generation distribution systems requires a highly accurate real-time monitoring for state estimation and situational awareness. This paper considers the problem of robust placement of a limited number of voltage magnitude meters and phasor measurement units for state estimation in an active distribution system comprising topological reconfigurations. The trace of the inverse of the Fisher information matrix is chosen as criterion for the estimation accuracy. For meter placement in a single configuration distribution system, the greedy approach provides a near-optimal solution as well as a theoretical approximation guarantee. However, for meter placement in an active distribution system, a robust approach is required to optimize the worst case estimation accuracy among all possible configurations of the system. In this paper, a simple robust algorithm, called submodular saturation algorithm, for meter placement in active distribution systems is proposed. Numerical results on three different active distribution systems show that the submodular saturation algorithm outperforms the greedy algorithm and the genetic algorithm in most cases, and provides competitive results in other cases.