Experimental comparison of energy management strategies for a hybrid electric bus in a test-bench

Abstract

Energy management in hybrid and electric vehicles is a key factor to improve the operational performance and meet the efficiency objectives defined in the transport sector. Thus, optimized energy management strategies (EMS), before being integrated in a real system, need to be validated in a scaled test-bench platform in order to identify the possible deviations from the expected simulation-based profiles, thus, saving time during the implementation in the real application. An economical and flexible way of validating these strategies is the Hardware-in-the-loop (HIL) simulation. In this framework, this work aims to compare the experimental results of two optimized (simulation-based) EMSs applied on a hybrid electric urban bus (HEB) in terms of real-time operational performance. Both EMSs handle the proper power split behavior of the vehicle demand between a genset (internal combustion engine connected to an electric generator) and a hybrid energy storage system (combining Li-ion batteries with supercapacitors). The hardware in the test-bench consist of a scaled electrical DC grid of an HEB. This hardware platform is combined with software models allowing to emulate the real behavior of the genset, battery, supercapacitor, traction and auxiliary loads.