A power-sharing electro-hydraulic actuator system to downsize electric motors for electric mobile machines

Hydraulic drives are popular in multiple industries due to their high-power density, robust operation, and low cost. However, they often suffer from low energy efficiencies, particularly in mobile applications where multiple functions are powered by a single pump. Decentralized hydraulic solutions, such as electro-hydraulic actuators, have emerged as a more efficient alternative. Nevertheless, the oversized electric motors compared to centralized solutions prevent it from penetrating the market. Therefore, in this paper, a power-sharing electro-hydraulic actuator system with planetary gearsets is proposed. This system allows for high-level system efficiency and downsized electric drive system, making it applicable to a wide range of applications. A minimum power loss strategy and system parameter optimization are proposed. The system operation and energy comparison between proposed system and baseline system is presented. Result shows the total installed motor power of proposed system is reduced by 37.0 % (from 138 kW to 87 kW) with a slightly lower overall efficiency.