Integrated distribution system optimization using a chance-constrained formulation

The rapidly rising penetration level of distributed generators (DGs) increases the risk of unacceptable voltages in distribution systems. The conventional voltage regulation devices are limited by physical constraints in their ability to perform voltage/var control in response to photovoltaic (PV) output fluctuations. However, the reactive power capability of PV inverters alongside with conventional voltage regulation devices can be used to address this challenge. This paper proposes a integrated volt/var method based on a control action ahead of time to find both the optimal voltage regulation tap settings and PV reactive control parameters in which the maximum expected system performance with respect to a figure of merit of interest can be achieved while maintaining appropriate system voltage magnitudes and considering the uncertainty of PV power injections over the interval of interest. The effectiveness of the proposed method is validated using a modified IEEE 123-node radial distribution system.