Abstract: Due to energy crisis and environmental pollution in the world range, it is urgent to develop new solutions for excavators which are widely applied with low efficiency. As a well-known energy-saving solution, oil-electric hybrid driven technology which combines a diesel engine and an electric motor together has received significant breakthrough in vehicles, for engine efficiency can be improved and energy regeneration can be realized. There are many differences between excavators and vehicles such as load condition, regeneration approach, energy storage, operability and reliability. Therefore, it is necessary to investigate the hybrid driven technology of excavators specially. The key technologies of oil-electric hybrid excavators in China, abroad and especially in SKLoFP of Zhejiang University are reviewed on power hybridization mode and parameter optimization, power system control, electric swing and braking kinetic energy regeneration, boom potential energy regeneration and generator. The research results are validated in a prototype of 20 t hybrid excavator and can also be extended to other construction machinery.

Key words: Energy recovery, Excavator, Hybrid power, Oil-electric hybrid