Energy-efficient design of the powertrain for mechanical-electro-hydraulic equipment via configuring multidimensional controllable variables

Energy-saving techniques are critical for the low-carbon design of equipment. Focusing on global energy efficiency during operation, a powertrain with multidimensional controllable variables (MCVP) is developed to reduce the installed power and energy consumption of mechanical-electro-hydraulic equipment working under various conditions. By altering the combination of controllable variables, the output characteristics of the powertrain can be adjusted to match the demands of various working conditions. This approach fundamentally and comprehensively addresses the issues of overflow losses and low energy conversion efficiency in equipment. To realize the energy-saving potential of the powertrain, an optimized design method is presented to improve the degree of matching between the load and the powertrain. A dual-layer energy-saving control strategy is proposed for high energy efficiency and tracking accuracy. The first layer is the energy-saving strategy which is executed to find the optimal combination of the controllable variables. The second layer is a controller which is employed to ensure tracking accuracy. Three case studies are analyzed to validate the effectiveness of the powertrain and the control strategy. The installed power and total energy consumption are reduced by 41.7% and 26.9% for a large-ton hydraulic press, respectively. Then, the energy-saving ratio is up to 18.5% for a small-ton hydraulic press. A mechanical powertrain has 26.6% and 17.2% reduction ratios of the installed power and the energy consumption, respectively. Finally, the control performance meets the requirements based on the designed controllers. Furthermore, the extension concept and more specific configurations of the MCVP are discussed for broader applications.