Optimal transient control of power generation in hybrid construction equipment

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.