SLP Optimization-Based Voltage Profile Improvement in Unbalanced Distribution Networks With SOP Devices

Abstract

The deployment of renewable energy resources (RER) such as photovoltaic (PV) and wind turbine (WT) systems has significantly improved the operation of active distribution networks (ADN). This can be seen in the technical, economic, and also environmental benefits observed over the past decade. However, since these resources have intermittent nature, they usually cause voltage and frequency fluctuations, which leads to increased system losses and instability. In this paper, sequential linear programming (SLP) is used to improve the voltage profile of unbalanced distribution networks. The method is applied to a modified IEEE-34 node test feeder. Three PV systems are installed in the system, and two of them are connected through a soft open point (SOP). The method optimizes the reactive power flow through the SOP and the third PV coming from the smart inverter, as well as the taps of the voltage regulators to reduce the voltage deviation from the reference voltage value. The voltages in the base and optimum cases are compared for each time simulation with and without the use of SOP. The results show that a more improved voltage profile is obtained after the use of SOP.