An Overview of Energy Savings Approaches on Hydraulic Drive Systems

Different procedures to improve the energy efficiency of a hydraulic drive system have been surveyed in this article. The energy-saving approaches are classified into four categories: hybridization, control algorithms, waste energy recovery and reduction of energy losses. Also, the sub-categories of each strategy are discussed individually in brief. The energy efficiency can go up to 69% using a hybridization strategy, whereas using a fuel-saving strategy is within the range of 20–40%. Another strategy, i.e., control algorithms, yields 40% of fuel savings on the displacement-controlled excavator system. Similarly, the maximum potential to recover the braking energy is about 78% in the case of the Constant Pressure System (CPS) system using flywheel under the category of waste energy recovery. Moreover, 56–66.1% throttling energy saving potential is observed on an On/Off high-speed valve-controlled hydraulic system under the reduction of energy loss strategy. Different energy saving potentials of the hydraulic system have been presented in tabular form for a clear understanding of the historical development in this field.