Analysis of battery charger topologies for an electric vehicle

This article focuses on fast chargers of electric vehicles. One of the crucial parts of a fast charger is the secondary charging converter that must be able to regulate efficiently battery charge voltage and current. To be able to use the electric vehicle battery as a temporary energy storage in the electric grid, the topology of a charging converter must enable a bidirectional energy flow. Bidirectional converters need an additional boost circuit to stabilize the battery voltage while draining energy from it. Class 3 unidirectional charging converters could be realized with a current doubler rectifier topology and bidirectional ones with a controllable full-bridge rectifier/inverter, resulting from its advantage over the current doubler in this operational mode. A quasi Z source could be used as a filter/boost circuit.