Abstract
Energy saving effects of series and parallel hybrid applied in construction machinery are compared. Theoretical calculation of fuel consumption and evaluation of energy saving effect are implemented to a system combined by motor energy regeneration, separate driving, electrical motor directly driving rotary actuator, meter-out control and parallel hybrid system. The results can be used to direct the research on energy saving in construction machinery. Considering the factors of manufacturing cost, operation performance and component performance, etc, a new system combined by all above mentioned methods except for motor energy regeneration is put forward as the current main developing program.