Active distribution system state estimation incorporating photovoltaic generation system model

The inherently intermittent and varying power generation of distributed energy resources (DER) makes the situational awareness of active distribution systems (ADS) a challenging issue. Considering the detailed photovoltaic (PV) system model and environmental influencing factors including solar irradiance and temperature, this paper develops a state estimation model for the ADS with integrated PV power generation systems. Firstly, in order to achieve high computational efficiency, an explicit function fitting model of PV arrays is proposed and used to accurately approximate the conventional five-parameter model. Then, the state variables of a PV generation system are selected, and the measurement equations and the Jocobian matrix are derived. Finally, combined with the conventional distribution network model, state estimation and bad data processing of an ADS with PV systems are realized. A generalized per unit system is also developed for unified standardization of electrical and non-electrical quantities. Simulation results in the IEEE 33-bus system show that the proposed model significantly expands the scopes and capabilities of state estimation and bad data processing in ADSs, which facilitates comprehensive and reliable monitoring of ADSs.