End-Winding Microchannel Cooling for High-Torque Electric Motors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cooling systems for high-torque electric motors, such as those used in electric vehicles, fail to effectively cool the end-windings, leading to localized hotspots and thermal resistance issues that limit power density and reliability.
Innovation Solution
A direct thermal contact end-winding microchannel heat exchanger system using two-phase coolant within the end-windings, allowing for high filling factors and modular assembly, which directly extracts heat from the windings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If water jacket cooling is used to cool the active winding region, then cooling effectiveness is improved, but the end-windings are not effectively cooled causing localized hot spots
Solution Approach 1:
The cooling system is segmented into two distinct parts: water jackets for cooling the active winding region and spray cooling nozzles for cooling the end-windings. This segmentation allows each cooling method to be optimized for its specific target area, resolving the contradiction by ensuring both regions are effectively cooled through dedicated cooling pathways.
Solution Approach 2:
Different cooling approaches are applied to different regions: water jackets provide distributed cooling for the active windings, while spray cooling nozzles provide concentrated, high-flux cooling for the end-windings. This local quality differentiation ensures that each region receives the appropriate cooling intensity and method, eliminating hot spots while maintaining overall thermal balance.
2Temperature
If spray cooling is used to cool end-windings, then heat dissipation effectiveness is improved, but reliability issues arise due to nozzle corrosion and erosion
Solution Approach 1:
The design incorporates protective measures against nozzle corrosion and erosion from the outset, such as selecting corrosion-resistant materials for the nozzles and positioning them to minimize exposure to harsh chemical and mechanical environments. This beforehand cushioning prevents the reliability issues that would otherwise arise during operation.
Solution Approach 2:
The spray cooling nozzles are constructed using composite materials or coated with corrosion-resistant layers that combine the cooling functionality with enhanced durability. This allows the system to maintain effective heat dissipation while resisting the corrosive and erosive effects of the coolant and operating conditions.
3Power
If high current density is implemented to increase power density, then motor power output is improved, but thermal management becomes more difficult
Solution Approach 1:
The cooling system merges multiple cooling methods (water jacket cooling and spray cooling) into a unified thermal management solution. This combination allows the system to handle the increased thermal loads generated by high current density operations, as the dual cooling approach provides greater total cooling capacity and more uniform heat distribution.
Solution Approach 2:
The spray cooling system utilizes phase transition of the coolant (liquid to vapor) at the end-winding surfaces to achieve highly efficient heat removal. This phase change mechanism provides intense cooling exactly where needed, enabling the motor to sustain high current densities without excessive temperature rise.
4Temperature
If direct cooling techniques are used to reduce thermal resistance, then cooling efficiency is improved, but manufacturing complexity and maintenance difficulty increase
Solution Approach 1:
The direct cooling system is segmented into modular components: water jackets that can be separately manufactured and installed, and spray cooling nozzles that are positioned and adjusted independently. This segmentation simplifies manufacturing by allowing each component to be produced using standard techniques, while still achieving low thermal resistance through direct contact cooling.
Solution Approach 2:
The water jackets and spray nozzles serve as intermediary structures that facilitate direct thermal contact between the coolant and windings without requiring complex integration. These intermediaries simplify the overall manufacturing process by providing standardized interfaces and mounting arrangements that reduce assembly complexity.
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 system significantly reduces thermal resistance, enabling higher current densities and maintaining winding temperatures below critical thresholds, enhancing thermal management and reliability while preserving electromagnetic performance.
Implementation Method 1
direct thermal contact end-winding microchannel heat exchanger... in direct thermal conduction with a section of the plurality of windings that extends beyond the first end to remove heat from the plurality of windings
Implementation Method 2
intertwined microchannels (carrying two-phase coolant)... directly extracts heat from the windings
Data Source
AI summary
An electric machine including a direct thermal contact end-winding microchannel heat exchanger is provided. A plurality of insulators are coupled to a stator. A plurality of windings are coupled to the plurality of insulators. A direct thermal contact end-winding microchannel heat exchanger is coupled to a section of the plurality of insulators that extends beyond the stator. The direct thermal contact end-winding microchannel heat exchanger is in direct thermal conduction with a section of the plurality of windings that extends beyond the first end to remove heat from the plurality of windings. According to other illustrative embodiments, a method and modular machine are provided.