Conservation voltage reduction based comprehensive power management scheme for an isolated solar photovoltaic battery based microgrid

Use of Battery in standalone system can offer number of benefits in terms of energy management, reduction of dependency on fossil source and voltage regulation. In this study, a power management technique considering conservation voltage reduction (CVR) along with droop control method is proposed for a standalone system supplied from Photovoltaic (PV) source and battery. The proposed power management scheme ensures that under all operating conditions, the battery is neither overcharged nor completely discharged. It further ensures that under no condition, the power limit of battery charging as well as battery discharging controller is exceeded. The proposed method also aims to minimize the size of overall Photovoltaic battery (PVB) system to reduce the total investment and operation cost considering energy saved achieved by CVR, while satisfying system operational constraints. The proposed method also reduces the number of charging/discharging operations of battery to enhance its life. The validity of the proposed power management scheme has been extensively tested on a European distribution system through PSCAD/EMTDC simulation studies as well as on real time digital simulator (RTDS). The simulation results indicate that the combination of CVR and Droop control can achieve appreciable energy savings.