Interior Permanent Magnet Rotor for Vehicle Powertrain Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric machines for vehicle powertrains face challenges in achieving high efficiency, power density, torque density, and compact packaging while minimizing cost, mass, and inertia, particularly in meeting a wide peak power range and maximum speed requirements.
Innovation Solution
The electric machine incorporates a rotor assembly with a rotor core configured to support permanent magnets and multiple barrier layers, optimized geometry, and a multi-phase stator assembly, enabling high efficiency, high torque density, and low mass, with an interior permanent magnet assisted synchronous reluctance rotor design that fits within a small packaging space and operates effectively across a wide speed range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional electric machine designs are used, then packaging space is reduced, but power density and torque density cannot achieve high levels simultaneously
Solution Approach 1:
The rotor core is segmented into multiple barrier layers at each rotor pole, with each layer housing permanent magnets. This segmentation allows optimized magnetic flux distribution and enables high power density within compact packaging space by efficiently utilizing the rotor volume.
Solution Approach 2:
The rotor assembly uses composite construction combining permanent magnets with rotor core material in multiple barrier layers. This composite approach achieves high torque density and power density while maintaining compact dimensions suitable for vehicle powertrain integration.
2Loss of energy
If high efficiency is achieved through optimized geometry and permanent magnet usage, then mass and inertia increase, but the requirement is for low mass and inertia
Solution Approach 1:
Permanent magnets are selectively placed in specific barrier layers at rotor poles where they provide the greatest efficiency benefit. This local quality approach optimizes energy efficiency by concentrating magnetic material in critical regions rather than uniformly distributing it, thereby reducing overall mass and inertia.
Solution Approach 2:
The design uses reduced magnet usage by implementing multiple barrier layers with permanent magnets only in selected layers. This partial action approach achieves the required efficiency level (80% over defined operating range) while minimizing magnet material and associated mass, satisfying both efficiency and low mass requirements.
3Adaptability or versatility
If the electric machine is designed for wide peak power range and maximum speed, then device complexity increases, but cost minimization is required
Solution Approach 1:
The rotor assembly with multiple barrier layers and permanent magnets is designed to provide universal performance across wide peak power ranges and maximum speeds. The same structural configuration delivers efficient operation in engine cranking, regeneration, and torque assist modes, reducing design complexity by avoiding mode-specific components.
Solution Approach 2:
The electric machine incorporates dynamic performance capabilities through its rotor design, enabling adaptation to varying operating conditions (cranking, regeneration, torque assist) without mechanical adjustments. The electromagnetic design naturally accommodates wide speed ranges and power demands, simplifying control system complexity while maintaining cost-effectiveness.
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 solution achieves 80% efficiency over a defined output power and speed range, supports a maximum speed of 18,000 rpm, and provides engine cranking, regeneration, and torque assist modes with reduced magnet usage and weight, ensuring efficient and compact operation.
Implementation Method 1
An electric motor utilizes electric potential energy to produce mechanical torque through the interaction of magnetic fields and electric current-carrying conductors
Implementation Method 2
Some electric motors can also function as generators by using torque to produce electrical energy
Implementation Method 3
an interior permanent magnet assisted synchronous reluctance rotor assembly
Data Source
AI summary
An electric machine is provided that includes a rotor assembly having a rotor core configured to support permanent magnets spaced around the rotor core to define a number of rotor poles. The rotor core has multiple rotor slots arranged as multiple barrier layers at each of the rotor poles. The rotor core is configured so that the electric machine satisfies predetermined operating parameters. In one embodiment, the electric machine is coupled with an engine through a belt drive train and provides cranking (engine starting), regeneration and torque assist modes.