Modeling and control of Plug-In Hybrid Excavator

The electric excavator is being developed in the field of construction machine for energy cost savings and the reduction of the exhaust gas compared to the conventional engine-driven excavator. However, the current battery capacity is insufficient to cover the working hours. So, we need to design the Plug-In Hybrid Excavator in the form of auxiliary engine & generator to charge the battery. The Plug-In Hybrid Excavator is composed of an electric motor to drive a hydraulic pump, a battery to generate electrical energy and an auxiliary engine/generator to charge a battery. It is designed to work by consuming the electrical energy of a battery. In this system, when the battery SOC drops below a certain range, an auxiliary engine & generator charges the battery. In this paper, the Plug-In Hybrid Excavators are modeled which applied the control strategy of the Series, Parallel, and Dual- Mode Power-Split type Hybrid system. This paper aims at the comparison of their control structures and their operation modes. The simulation is conducted to verify the feasibility of the power distribution mechanism and to compare with the performance of energy efficiency through results.