Zonal Electro-Hydraulic Power Generation in Commercial Aircraft

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This thesis explores zonal electro-hydraulic power generation as an alternative to conventional central hydraulic systems, utilizing multiple smaller systems. Hydraulic power is generated by electric motor-driven pumps in hydraulic power packages (HPP) that supply specific aircraft zones, allowing for the retention of proven hydraulic actuators in future electric architectures. However, zonal systems present challenges such as increased weight, higher thermal loading, and greater noise emission, alongside varying duty cycles. To tackle these issues, the thesis introduces a zonal HPP concept featuring redundant speed-variable electric motor pumps (EMPs) with internal gear pumps, complemented by efficient control strategies. Given the lack of aerospace experience with EMP technology, initial verification is conducted through experiments with a representative prototype. A robust electronic pressure control concept is developed to facilitate single and dual EMP operation, overcoming stability issues associated with current hydro-mechanical pressure compensators. For specific zonal systems like main landing gear and primary flight controls, advanced control strategies are created to meet objectives such as reduced peak power demand, lower thermal loading, and enhanced dynamic performance. These strategies are validated through experiments on a test rig with EMPs and relevant consumers. Finally, thermal-dynamic simulations analyze o