Sensitivity-based and optimization-based methods for mitigating voltage fluctuation and rise in the presence of PV and PHEVs

Voltage fluctuation and voltage rise are common issues associated with the massive integration of photovoltaic (PV) technologies in distribution systems. In this paper, sensitivity-based and optimization-based methods are proposed for mitigating voltage fluctuation and rise in the presence of plug-in hybrid electric vehicles (PHEVs). The concept of these methods is to optimize the reactive power of PV inverter and active power from charging station of PHEVs for matching a target voltage profile. The sensitivity-based method is based on the first-order power flow sensitivities around the desired voltage profile. An optimization model is used in optimization-based to minimize the mismatches between the fluctuating and required voltage profiles. The charging/discharging operation of PHEVs and reactive power of PV inverter are simultaneously controlled for compensating power fluctuation during cloud transients and load fluctuations. The results demonstrate the effectiveness of the proposed methods compared with existing methods.