Dual Electric Machine Drive for Aircraft Engine Restart Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current aircraft systems lack the flexibility to efficiently manage combustion engines during various flight phases and operational modes, particularly in terms of power distribution and engine restart, which limits their multi-use capabilities and reliability.
Innovation Solution
An aircraft with a power plant comprising at least one combustion engine connected to a drive system featuring two electric machines, each connected via a kinematic chain, and a manager that controls the electric machines to deliver different mechanical powers or torques, enabling multiple operating modes including a higher operating mode for enhanced functionality and redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simplex drive system with one electric machine is used, then the device complexity is reduced, but the reliability and versatility of the combustion engine operation are insufficient
Solution Approach 1:
The drive system is segmented into two independent electric machines (first and second electric machines), each capable of independently setting the mobile system in motion. This segmentation provides redundancy and reliability, as the failure of one electric machine does not prevent combustion engine operation, while maintaining manageable system complexity through modular architecture.
Solution Approach 2:
The system dynamically adapts its configuration by allowing the two electric machines to operate in different modes (both in motor mode, one in motor mode and one in generator mode, or both in generator mode) depending on the operational phase. This dynamic flexibility enhances reliability across various scenarios without requiring a completely different system design for each mode.
2Use of energy by moving object
If the combustion engine is inactivated during flight, then fuel consumption is reduced, but the ability to restart the engine requires a reinforced restart system increasing complexity
Solution Approach 1:
The electric machines serve dual purposes: they can act as starters to set the mobile system in motion during engine restart, and as generators to produce electrical energy during engine operation. This self-service capability eliminates the need for separate dedicated restart systems, reducing overall complexity while enabling fuel-efficient engine inactivation during flight phases.
Solution Approach 2:
The electric machines are designed with multi-functionality, capable of operating in motor mode for engine starting, generator mode for electrical power production during flight, or idle mode during engine inactivation. This universal design allows the same components to handle both fuel efficiency requirements and restart capabilities without additional specialized equipment.
3Adaptability or versatility
If a reinforced restart system is implemented, then the versatility of operating modes is improved, but the device complexity increases
Solution Approach 1:
The two electric machines provide universal functionality across all operating modes: they can simultaneously or independently operate in motor mode for engine starting, generator mode for electrical power during flight, or remain idle. This multi-functionality achieves high operating mode versatility without requiring separate specialized systems for each function, thereby limiting complexity increase.
Solution Approach 2:
The system merges the functions of engine starting and electrical power generation into the same two electric machines. Instead of having separate dedicated starters and generators, the electric machines are combined to perform multiple functions, achieving versatility while reducing overall system complexity through functional integration.
4Adaptability or versatility
If two electric machines are used in a drive system, then the reliability and versatility are improved, but the device complexity increases
Solution Approach 1:
The control system dynamically manages the two electric machines across different operational phases, adapting their modes (motor, generator, or idle) based on flight conditions. This dynamic control achieves high operating mode versatility while keeping the underlying hardware architecture relatively simple and manageable, as the same physical components serve multiple functions through dynamic reconfiguration.
Solution Approach 2:
The system merges multiple functions (engine starting, electrical power generation, engine ventilation) into the two electric machines. By combining these functions rather than using separate dedicated systems, the achieve high versatility without a proportional increase in device complexity, as the same components handle multiple tasks through intelligent control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for efficient power management and engine restart during flight, ensuring reliable operation across different modes and conditions, including rapid restarts and ventilation, thereby enhancing the aircraft's versatility and reliability.
Implementation Method 1
an electric machine that can be set in motion by an electrical machine to set the mobile system in motion
Implementation Method 2
an electric machine that can operate in an electric motor mode and an electric generator mode depending on the need. In electric generator mode, an electric machine is set in motion to generate electrical energy
Data Source
Figure 1~2
AI summary
The present invention relates to an aircraft (1) equipped with a propulsion system (10) having at least one internal combustion engine (20) mechanically connected to a drive system (30), the drive system (30) comprising two electric machines (35, 40) each connected by a kinematic chain (50) to the internal combustion engine (20), the two electric machines (35, 40) being electrically connected to at least one electrical power source (60). The aircraft (1) includes a controller (70) managing at least one mechanical power or motor torque delivered by each of the two electric machines (35, 40) according to a normal operating mode, said controller (70) being configured during a higher operating mode to control the two electric machines (35, 40) so that the two electric machines (35, 40) deliver different and unaffected mechanical powers or motor torques.