Assessing the use of BESS against PV-induced voltage increases on low voltage networks through local and centralized controllers

Abstract

The value of renewable energy systems has been increasing due to the current global climate change. Given the economic benefits to the end users and the incentives created for the uptake, householders have accelerated the use of this form of energy. Photovoltaic (PV) systems, an important part of renewable energy, assist the energy provision needed in households. In any residences, once the harvesting energy produced by the PVsystem is greater than the amount consumed in the household, the remaining energy is injected to the grid. While this situation provides economic benefit to the residential customer, it might cause voltage increases at the node which the residence is connected to. This factor might affect profitably utility companies and customers as a negative increase in voltage level. One of the possible solutions to this problem is to deploy battery energy storage systems (BESS) connected to the PV system in a household. In order to simulate this, a real BESS: Tesla Powerwall 2 was modeled in this study. Two different control methods (local and central) were investigated for the effective use of BESS against voltage increases. In addition, for each method, the energy capacity (kWh) and charge/discharge power (kW) of BESS were changed and the adverse effect of BESS on voltage increases was quantified. As a result, it is seen that central control is more effective in managing the voltage rise and compared to local control, it is more realistic in terms of utilization. Additionally, in both control methods, it is observed that when the BESS energy capacity (kWh) is increased or the BESS charge/discharge power (kW) is altered, the rise in voltage level is reduced. It is expected that these results will contribute to preventing and/or managing problems that may occur with PVsystems in households.