Stochastic Assessment of Voltage Unbalance Mitigation by Battery System in case of Single-Phase Solar Generation

Abstract

The electric power system face big challenges today. Environmental concerns and political decisions that follows, are up to reshape electrical energy industry and change the way how energy is managed. One of the key ideas of forthcoming changes is to utilise renewable energy sources, such as solar. However, solar generation, as any other distributed generation, sets strain on the power system and power quality properties can be negatively affected. In this paper, the voltage unbalance (VU) caused by single-phase connected photovoltaics (PV) in residential low voltage grid are assessed by Monte Carlo Simulation (MCS). The voltage unbalance mitigation possibilities by battery energy storage system (BESS) are evaluated, by connecting the battery in a three different phase connection strategies. Two different stochastic assessment models will be tested: time independent and time series models. The results of the two models are presented and discussed in depth.