Aircraft Hybrid Electric Propulsion Fail Mode for Battery-Conserving Landing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hybrid electric propulsion systems for aircraft face challenges in managing power distribution during generator failures, leading to rapid battery drainage and inability to maintain thrust for controlled landings due to insufficient battery capacity and power management complexity.
Innovation Solution
A hybrid electric propulsion system with a supervisory controller that detects generator failures, transitions into a generator-motor fail mode to conserve battery power by reducing power draw to non-essential systems, spooling down motors, and windmilling until a safe altitude is reached, then switches to a landing battery mode to restore thrust for controlled landings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery powers the propulsion system during generator failure, then thrust can be maintained for controlled landing, but the battery drains rapidly and depletes its capacity
Solution Approach 1:
The system applies partial action by delivering battery power to only essential systems during generator-motor fail mode rather than all systems. The controller prioritizes propulsion system power delivery over non-essential electrical systems, providing just enough power to maintain controlled descent and landing capability while conserving battery capacity.
Solution Approach 2:
The power management system segments electrical systems into essential and non-essential categories. During generator-motor fail mode, the controller selectively powers only essential systems (propulsion) while shutting down or reducing power to non-essential systems, thereby extending battery operating time while maintaining critical functions.
2Reliability
If the battery capacity is increased to maintain thrust longer during generator failure, then controlled landing capability is improved, but the system weight and complexity increase
Solution Approach 1:
Instead of sizing the battery for full propulsion power over extended periods, the system uses partial action by providing power only to essential systems during failure modes. This allows a smaller, lighter battery to achieve the same reliability goal of maintaining controlled landing capability.
Solution Approach 2:
The system changes operational parameters dynamically based on flight conditions. The controller monitors altitude, battery state of charge, and system status to adjust power delivery thresholds and system shutdown sequences, optimizing battery usage to extend operational duration without increasing battery capacity.
3Loss of energy
If the system shuts down non-essential systems during generator-motor fail mode, then battery power is conserved, but system complexity in managing power distribution increases
Solution Approach 1:
The system performs preliminary actions by pre-configuring power distribution priorities and system shutdown sequences before failures occur. The controller is pre-programmed with power management strategies that automatically execute during generator-motor fail mode, reducing the need for complex real-time decision-making and simplifying the control logic.
Solution Approach 2:
The power management system uses feedback from sensors monitoring battery state of charge, system status, and flight conditions to dynamically adjust power distribution. This closed-loop control optimizes battery conservation while maintaining essential functions, managing complexity through adaptive rather than purely predetermined control strategies.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A hybrid electric propulsion (HEP) system included in an aircraft includes a generator (103) configured to output a first power, an energy storage system (102) including a battery (124) configured to output a second power, a propulsion system (205) configured to generate thrust based on at least one of the first power and the second power, and an HEP controller (200) in signal communication with the generator (103), the energy storage system (102), and the propulsion system (205). The HEP controller (200) is configured to detect loss of the first power output from the generator (103), to determine an altitude of the aircraft and to actively control delivery of the second power to the propulsion system (205) based on the altitude during the loss of the first power.