Switched Reluctance Machine Toroidal Winding High Speed Thermal Management
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Solution Overview
Problem
Conventional switched reluctance machines face inefficiencies due to high copper and stator core material usage, leading to increased losses and reduced thermal performance, especially at high speeds above 25,000 RPM.
Innovation Solution
The implementation of a switched reluctance machine design featuring toroidal core windings around a salient stator core with paired coil windings on either side of each stator pole, reducing copper volume and stator core material, and incorporating cooling channels for improved thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional windings on stator teeth are used, then electromagnetic field generation is achieved, but copper volume and stator core material increase leading to higher losses
Solution Approach 1:
The patent transitions from conventional planar windings on stator teeth to toroidal windings that wrap around the stator core in a three-dimensional configuration. This dimensional change allows the windings to encircle the core completely, creating a more efficient magnetic circuit that reduces both copper losses and core material requirements while maintaining the electromagnetic field generation function.
2Temperature
If conventional winding configuration is used, then stator core provides magnetic path, but thermal performance deteriorates at high speeds above 25,000 RPM
Solution Approach 1:
The patent divides the stator core into multiple segments with cooling channels positioned between them. This segmentation allows cooling fluid to flow through the stator core, effectively removing heat generated during high-speed operation. The toroidal windings are also segmented and positioned to facilitate thermal management, enabling the machine to maintain thermal performance at speeds exceeding 25,000 RPM.
3Power
If more copper and stator core material are used, then electromagnetic field strength increases, but power-to-weight and torque-to-weight ratios decrease
Solution Approach 1:
The patent changes the geometric parameters of the winding configuration from conventional planar to toroidal, and adjusts the stator core segmentation parameters to optimize the magnetic circuit. These parameter changes enable the machine to achieve the required electromagnetic field strength with reduced copper volume and stator core material, thereby improving power-to-weight and torque-to-weight ratios.
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 design reduces copper and stator core losses, enhances thermal performance, and allows for higher power-to-weight and torque-to-weight ratios, enabling robust operation up to 50,000 RPM with reduced noise sensitivity and material usage.
Implementation Method 1
Each corresponding pair of coil windings may be configured to induce magnetic flux through the stator pole to excite the stator pole
Implementation Method 2
A reluctance machine is an electric machine in which torque is produced by the tendency of the movable part of the machine to move into a position where the inductance of an excited winding is maximized
Data Source
AI summary
A switched reluctance machine has a stator core salient with stator poles disposed concentrically with a rotor that is salient with rotor poles. A plurality of coil windings are wound about the stator core so that a pair of windings are adjacent each of the stator poles. The pair of coil windings induces magnetic flux in the adjacent stator poles and the rotor rotates to align the rotor poles with the stator poles having the induced magnetic flux. The rotor is rotatable at high speeds of up to 50,000 RPM and the coil windings can be directly cooled.