Comprehensive analysis and cost estimation of five-level bidirectional converters for electric vehicles operation in smart cities context

Abstract

A comprehensive analysis, comparison and cost estimation of five-level bidirectional converters for the electric vehicle (EV) operation in smart cities context is presented in this paper. Nowadays, five-level converters are widely used with success to interface between the power grid and renewable energy sources, as well as, to operate as motor drivers. Therefore, with the EV introduction into the power grids arises a new opportunity to use such five-level converters as interface between the power grid and the EV batteries, i.e., in on-board charger applications. Moreover, considering the future scenarios of smart grids and smart cities, the five-level bidirectional converters will be essential for the operation modes grid-to-vehicle (G2V, charging the batteries from the power grid) and vehicle-to-grid (V2G, returning energy from the batteries to the power grid). In this context, this paper presents an aggregation of the most important five-level bidirectional converter topologies that can be applied for on-board EV chargers in smart cities context. Along the paper it is presented a detailed description of the hardware and control algorithms of the five-level converters, and are also presented and explained simulation results performed under realistic operating conditions. Finally, it is presented the cost estimation for a real application considering the hardware requirements for each one of the converters.