Optimal active and reactive power dispatch in a distribution network with high PV penetration

Abstract

Integration of rooftop photovoltaic (PV) panels at the distribution network is on the rise. This trend is in part due to the global concerns for climate change as well as the need to find an alternative source of energy. However, if not properly coordinated, deploying renewable energy resources such as solar energy in the power grid can introduce challenges of its own. For instance, high penetration levels of PV may lead to overvoltage conditions, which can in turn cause additional stress on electrical components. In order to cope with such challenges, the operation of the distribution system has to be optimized while considering PV resources. Since irradiance at the ground level and daily load variations are stochastic in nature, a probabilistic approach is needed in order to provide a complete picture. This is what has been proposed in the current document. In this proposal, PV panels are assumed to contribute to reactive power support of the power grid, in addition to active power injection. Also, a centralized control of the distribution system is adopted. The controllable elements considered are voltage regulating transformers (voltage regulators), switching capacitors, load curtailment (or demand response), and the active and reactive powers provided by PV panels. The objective is to control the above devices in order to achieve operational goals such as improving system losses and the voltage profile, to name a few. A metaheuristic approach is used first to solve the problem. However, in order to improve the accuracy and reduce the convergence time, an analytical alternative is then proposed to optimize the performance of distribution system while considering photovoltaic integration.