Concentric Ring Auxiliary Power Unit for Electric Vehicle Range Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles are range-limited by the stored energy in their rechargeable energy storage system, leading to range anxiety when the energy level drops below a threshold, as they lack a supplementary power source for extended travel.
Innovation Solution
An auxiliary power unit (APU) is integrated into the electric vehicle, comprising a pair of concentric rings with an internal combustion engine and a power takeoff mechanism, connected to a transmission, which generates electrical energy when the onboard energy storage system's level falls below a threshold, extending the vehicle's range by enabling the APU to charge the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If an auxiliary power unit is added to extend range, then the vehicle's travel capability is improved, but the device complexity increases
Solution Approach 1:
The APU is nested within the spare tire compartment, utilizing existing vehicle space. The concentric ring generator is nested within the APU housing, with the inner ring containing the engine and the outer ring containing the generator components, maximizing space efficiency while adding range extension capability
Solution Approach 2:
The APU serves multiple functions: it generates electrical energy to extend range, and its rotating components can potentially serve as a flywheel energy storage system. The spare tire compartment serves dual purposes as both storage and housing for the APU, reducing overall vehicle complexity
2Volume of moving object
If a compact APU design is used to save space, then the volume occupied is reduced, but the manufacturing complexity increases
Solution Approach 1:
The concentric ring generator employs nested geometry where the inner ring with permanent magnets is positioned coaxially within the outer ring with induction windings. This nested arrangement achieves compact volume while maintaining manufacturability through standardized concentric component assembly
Solution Approach 2:
The APU adopts a flattened pancake-style engine design that reduces axial dimension, transitioning from a traditional three-dimensional volume to a two-dimensional planar configuration, thereby minimizing the space required while simplifying manufacturing through reduced assembly steps
3Use of energy by moving object
If the APU is activated to generate electrical energy, then the available energy is increased, but the energy consumption increases
Solution Approach 1:
The APU is designed to be self-regulating, automatically activating when RESS energy falls below a threshold and shutting off when the threshold is restored. The system monitors its own energy state and adjusts operation accordingly, minimizing unnecessary energy consumption while ensuring adequate range extension
Solution Approach 2:
The system dynamically adjusts the APU's operational parameters based on the RESS energy level, activating only when necessary and modulating power output to match the threshold requirement, thereby optimizing the balance between available energy and energy consumption
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
The APU effectively extends the electric vehicle's range by generating electrical energy when needed, reducing range anxiety by allowing the vehicle to be driven to a charging outlet or station, even when the onboard energy is low, thereby enhancing travel capabilities.
Implementation Method 1
The inner ring includes a plurality of permanent magnets. The outer ring includes a plurality of induction windings
Data Source
AI summary
An electric vehicle includes a transmission, motor, rechargeable energy storage system (RESS), auxiliary power unit (APU), and a controller. The APU has a pair of rings, at least one of which rotates with respect to the other. One ring is coaxial with and radially within the other. Ring rotation generates current in windings. A gear element is in driving connection with the rotatable ring. The APU includes an engine disposed radially within the inner ring, and a power takeoff mechanism coupled to the gear element. The controller energizes the APU to rotate a ring. A method includes positioning the APU in a vehicle body compartment, affixing an outer ring of windings to a compartment wall, and positioning a rotatable inner ring having permanent magnets radially within and coaxial with the outer ring. The engine is positioned radially within the inner ring. A power takeoff mechanism connects to the inner ring.