Abstract: A serial hybrid powertrain for bulldozer with independent dual-motor electric drive is put forward. The resistance characteristics for a single track are obtained from the bulldozer typical driving and operating conditions. The parameters of the dual electric motors and gear reduction ratios between motors and sprockets are designed and validated， considering the maximum power factor and the maximum bulldozer speed constraints. The parameters of the engine-generator and ultra-capacitor are determined based on the balance between the front and rear power chain. The mathematical model for the engine-generator and ultra-capacitor has been built. Dynamic programming is applied to verify the feasibility of the parameters designed for the fuel minimization during the typical and limiting conditions. The simulation results show that the parameters satisfy the power requirement of typical conditions and they could also meet the power requirement of limiting conditions.

Key words: hybrid powertrain;tracked bulldozer;parameter matching;dynamic programming