Interactive Distribution Expansion and Measurement Planning Considering Controlled Partitioning

Abstract

To model interactions among system expansion, con-trolled partitioning (CP), and observability, an integrated multi-period framework is developed in this paper for simultaneous planning of distribution systems and measurements with CP con-straints (DSMP-CP) in unbalanced multi-phase networks. The proposed framework, employing the network AC model, is formu-lated as a mixed-integer quadratically-constrained programing problem. This problem minimizes investment costs (including the costs of feeder reinforcement, distributed generation (DG) place-ment, and allocation of micro-phasor measurement units and their measuring channels) and operation costs (including the costs of DG operation, energy purchased from the upstream grid (UG), re-dispatching of DG and UG injections, and energy curtailment). A phase-based observability function is also introduced to ensure the observability of all phases of buses. Furthermore, the concept of zero-injection (ZI) property is proposed for ZI groups considering physical connections and mutual impedances among phases to en-hance observability efficiency and avoid suboptimal solutions. To enhance problem tractability and eliminate linearization errors, a duality-based solution approach is proposed employing an exact-ness loop with recursive re-linearization. The performance of the proposed framework is evaluated by testing it on the unbalanced IEEE 111-node and 256-node distribution test systems.