Voltage Quality Assessment in a Distribution System With Distributed Generation—A Probabilistic Load Flow Approach

There has been growing concern in distribution system planning regarding the potential impacts of distributed generation (DG) on power quality, specifically with regards to voltage limits, voltage imbalance, and flicker. The intermittent nature of renewable energy resources, such as wind and solar, makes a deterministic approach infeasible. It has been shown in the literature that probabilistic approaches must be adopted to truly assess the impact of DG units on the power system. This paper presents the findings of a probabilistic load-flow-based approach regarding the effects of renewable energy resources on the voltage quality in a distribution system. Statistical models have been utilized for modeling load, wind speed, and solar irradiance. Due to the unique nature of analysis, short duration variations of renewable resources have been modeled and taken into account. Simulation results are provided indicating how voltage quality is affected by distributed generation, especially on feeders with voltage regulators.