Toward Partial State Estimation of Distribution Network Under Novel Micro-PMU Placement

This paper proposes a partial state estimation of distribution network method based on a nonlinear dynamical system approach. The proposed method is globally convergent and can use sparse synchronized phasor measurements without the traditional requirement of network observability. For the application of voltage control or thermal limit control, enhancing the accuracy of the voltage amplitude or the voltage phase angle is required. Under this situation, we propose an enhanced formulation including the voltage amplitude measurement residual constraints and voltage phase angle measurement residual constraints. The IEEE 123-node test feeder, a three-phase unbalanced distribution system, is used to illustrate the effectiveness of the proposed method.