Optimal transient control of power generation in hybrid construction equipment

Abstract

Optimal energy management and power generation control in hybrid construction machines is presented. Power demand is often highly transient for construction equipment. The influence of the transient demand is studied by introducing powertrain speed dynamics in addition to energy storage dynamics in the optimal control problem. Solutions to the optimal control problem are derived and an approximate solution is proposed that can be used for on-line control. The well known equivalent consumption minimization strategy is extended and the new method introduces a new control parameter, fuel equivalent kinetic energy. Simulations of the on-line control strategy are presented and it is shown that they approximate the optimal control solutions well.

Energy management of hybrid electric vehicles with battery aging considerations: Wheel loader case study

“…In this case, instead of using SOC, available electrochemical energy of the battery (W ech = Q × U oc ) is taken as the system state. The corresponding dynamics is (Fröberg et al, 2011)…”

“…While development of optimal energy management policies for hybrid electric construction equipment is nothing new (Nilsson et al, 2015;Fröberg et al, 2011;Zhang et al, 2019), research on simultaneous optimization of fuel economy and energy storage system's durability is limited (Li et al, 2018). In this regard, to the best of the authors' knowledge, incorporation of battery degradation into energy management problem of hybrid electric wheel loaders and its potential advantages have not been studied yet.…”

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A comprehensive overview of hybrid construction machinery

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