Title: Determining optimal state of charge for a military vehicle microgrid
Authors: Denise M. Rizzo; Gordon G. Parker
Addresses: Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931, USA ' Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931, USA
Abstract: Military hybrid vehicles possess all the attributes of a microgrid - power generation, consumption, energy storage and the ability to operate in both grid connected and island mode. Therefore, a holistic view of energy use can be realised by considering a military hybrid vehicle as a microgrid and utilising energy optimisation methods from stationary microgrids, namely battery state of charge (SOC) optimisation. This paper describes a methodology to determine the optimal SOC for a given drive cycle to minimise fuel consumption. A two step approach was utilised where the first step used the drive cycle's speed profile to determine SOC basis functions. The second step used a numerical optimisation approach to determine the function weights that minimised fuel consumption using a dynamic model of the hybrid vehicle. A simulation example is presented using the US Army Urban Assault drive cycle. The approach reduced fuel consumption by 5.7% compared to using a fixed SOC level.
Keywords: hybrid vehicles; control optimisation; military vehicles; energy storage; battery SOC; state of charge; vehicle microgrid; hybrid electric vehicles; HEVs; optimal SOC; fuel consumption; dynamic modelling; simulation.
International Journal of Powertrains, 2014 Vol.3 No.3, pp.303 - 318
Received: 06 Mar 2013
Accepted: 21 Sep 2013
Published online: 30 Aug 2014 *