A Three Level Interleaved DC-DC Converter for EV Battery Charging from a Residential PV System

In a domestic photovoltaic (PV)-battery system, the battery stack serves as a backup power source, supplying household loads overnight and storing the excess solar energy but its expensive due to battery cost. On the other hand, Electric Vehicles which are becoming more popular, have an embedded battery that could be used as power buffers if these could be conveniently interfaced to the residential PV system.This paper proposes a bidirectional three-level interleaved (B3LI) DC-DC converter that can facilitate interconnection of the EV battery to the DC link of a PV inverter and avoids the need for an expensive bidirectional front end AC/DC charger. The main advantages of this topology are the utilization of multilevel and interleaving techniques which reduce magnetics size and the phase shedding control, which reduces the switching losses at low powers, which may be characteristic for the way the EV’s battery would operate when connected to the household PV system. The proposed B3LI converter is experimentally evaluated in a lab setting relevant to the applications.