Robust Measurement Placement for Distribution System State Estimation

This paper considers the problem of placing a limited number of measurements to improve the estimation accuracy in distribution system state estimation (DSSE). In distribution systems, intermittent distributed energy resources and volatile loads will result in a wide variation of system operating conditions. The proposed measurement placement problem is to decide the optimal locations and types of measurements to be placed in the distribution systems that minimize the worst-case estimation errors for DSSE over different system operating conditions. Four indices of the estimation error covariance matrix are chosen as the criteria of accuracy. The proposed measurement placement problem is formulated as a mixed-integer semidefinite programming (MISDP) problem. To avoid the combinatorial complexity, a convex relaxation, followed by a local optimization method, is employed to solve the MISDP problem. The proposed problem and the effectiveness of the proposed solution method are numerically demonstrated on the 33-bus distribution system.