Grid-interfaced Solar Photovoltaic Smart Building with Bidirectional Power Flow Between Grid and Electric Vehicle with Improved Power Quality

Abstract

This article proposes a grid-interfaced solar photovoltaic-based smart building with the features of bidirectional power flow capability through electrical vehicle charging/discharging and power quality improvements at AC mains with the optimum use of involved power converters. This solar photovoltaic power generating system is also used to charge the battery of electric vehicles that are kept in the basement parking of the smart building. The electric vehicles can serve buildings as uninterruptable power supply systems. The electric vehicle batteries are charged at lean demand periods and discharged to meet peak load demand, or they are charged at peak sun periods and power can be fed back to grid at night when there is no sun availability. The electric vehicle can act as a load or distributed energy source in a bidirectional power flow mode popularly known as vehicle to grid. During daytime, the active power is either injected to the grid or stored in the storage battery of the electric vehicle. The power quality improvement for power factor correction, harmonics elimination, voltage regulation, and neutral current compensation at AC mains is achieved using the same power converter. Vehicle to grid offers reactive power compensation, active power regulation, tracking of solar photovoltaic energy, and load balancing or load leveling, further increasing efficiency and reliability of the grid. As the proposed configuration is grid interfaced, this system is also used at night when there is no sun, thus leading to optimum utilization of the power electronics involved in this configuration.