MPC-Based Voltage/Var Optimization for Distribution Circuits With Distributed Generators and Exponential Load Models

This paper proposes a model predictive control (MPC)-based voltage/var optimization (VVO) technique considering the integration of distributed generators and load-to-voltage sensitivities. The paper schedules optimal tap positions of on-load tap changer and switch statuses of capacitor banks based on predictive outputs of wind turbines and photovoltaic generators. Compared with previous efforts on VVO which used constant-power load model, the exponential load model is used to capture the various load behaviors in this paper. Different customer types such as industrial, residential, and commercial loads are also considered. The uncertainties of model prediction errors are taken into account in the proposed model. A scenario reduction technique is applied to enhance a tradeoff between the accuracy of the solution and the computational burden. The MPC-based VVO problem is formulated as a mixed-integer nonlinear program with reduced scenarios. Case studies show the effectiveness of the proposed method.