Evaluation of the Impact of Rooftop Solar Power on the Power Quality of Vietnam Urban Distribution Networks according to Relevant Vietnamese and IEEE and IEC Standards

The goal of reducing greenhouse gas emissions and energy transition has created many favorable conditions to promote solar power generation technology. However, from a technical perspective, integrating solar power into the power grid poses many challenges in grid operation. This study investigates the impact of rooftop solar power in terms of power quality in the urban distribution grid in Vietnam. The current study simulated a typical low-voltage distribution grid with single-phase and three-phase loads to evaluate important power quality issues, such as Total Harmonic Distortion (THD) of voltage and current, voltage unbalance, and voltage rises. A grid simulation grid was developed in Matlab/Simulink under different conditions for the penetration level of solar power and the daily variation of loads. These indexes were compared with the limits specified in Vietnamese standards and the relevant international standards of IEEE and IEC. Compliance with the provisions of these standards was provided, even in the case of solar power systems with a high level of penetration into Vietnam's urban distribution grid.