A multi-level grid interactive bi-directional AC/DC-DC/AC converter and a hybrid battery/ultra-capacitor energy storage system with integrated magnetics for plug-in hybrid electric vehicles

Abstract

This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.

Centralized control of parallel connected power conditioning system in electric vehicle charge–discharge and storage integration station

“…Many research works on designing the topologies and controllers of bi-directional power electronic converters for EV application, which are able to function as battery charger and to transfer electrical energy between battery pack and the grid [11][12][13]. In addition, the centralized control system for parallel operation of the converters during grid-connected and stand-alone operations has been conducted [14][15][16].…”