Study on the impact of rooftop solar power systems on the low voltage distribution power grid: A case study in Ha Tinh province, Vietnam

Abstract

Vietnam has developed solar power very quickly in recent years. However, the integration of the solar power system into a distribution power grid can cause a clear effect on the voltage of the grid. Accordingly, the voltage at the nodes increases significantly because of the appearance of photovoltaic (PV) systems, and it can lead to overvoltage at some load nodes near the solar power source. The impact of solar power stations with distribution power grids depends on the location and operating conditions of the utility grid. Therefore, the study of the impact of rooftop solar power on the distribution grid needs to add actual operating data of the utility grid to achieve a more detailed assessment and reliability. This study analyzed the influence of rooftop solar power on a low voltage distribution power grid in Ha Tinh province, Vietnam with the support of ETAP software. The scenario was calculated for 50% of the power (3-phase) penetration gain of the transformer. Besides, a proposed synthetic solution is a combination of reactive power compensation with a 5kVAr minimum compensation level at many points on the grid and adjustment of the load tap at the appropriate level depending on the load situation of the transformer. Thus, the voltage of the nodes on the power grid is improved, and the power loss is also decreased.

Keywords

• Rooftop solar power
• Impact
• Low voltage
• Distribution power grid