Evaluation of Voltage Regulation Functions of Smart Inverters Based on Penetration Level and Curtailment in Photovoltaic Systems

In this study, we evaluate the Volt- VArand Volt-V AR-Watt functions of smart inverters based on the PV penetration level (PVPL) and the photovoltaic (PV) curtailment. The Volt- VArand Volt- V Ar- Watt functions are compared with the optimal control parameters that maintain the distributed network voltage within an admissible range and minimize PV curtailment. The study results at each PVPL (0-100%) with a typical distribution network model highlight the following points within our conditions. (1) Optimal control parameters vary with the PVPL and two weather conditions; (2) The maximum PVPL does not reach 100% with the Volt-V Arfunction, whereas the Volt-VAR-Watt function enables the maximum PVPL to reach 100%; and (3) the Volt-VAR-Watt function curtails PV generation, and the average ratio of PV curtailment on cloudy and sunny days is about 12.1 % and 0.16%, respectively.