Flat Conductor Coil Winding for Eddy Current Reduction
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Solution Overview
Problem
Electrical machines face challenges in achieving efficient cooling and energy-efficient operation, particularly in applications with high torque or power density requirements, where current heat losses dominate total losses and thermal load capacity is a critical concern.
Innovation Solution
The electrical machine features a coil winding with S-shaped or meandering turns made from flat conductors, which are bent around multiple parallel bending axes and have multiple layers or slot-shaped recesses for reduced eddy currents, allowing for efficient cooling and energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the current density in the coil winding is increased to achieve high torque or power density, then the power output is improved, but the heat losses increase significantly
Solution Approach 1:
The flat conductor is divided into multiple layers that are insulated from one another, segmenting the current path to reduce eddy currents and associated heat losses while maintaining high current density for power density
2Reliability
If the coil core is used to bundle magnetic flux to increase inductance and magnetic flux density, then the electromagnetic performance is improved, but the eddy currents in the conductor increase leading to higher heat losses
Solution Approach 1:
The conductor cross-section is segmented into multiple insulated layers, which interrupts the path of eddy currents induced by the bundled magnetic flux, reducing eddy current losses while maintaining the magnetic flux bundling effect of the coil core
Solution Approach 2:
Slot-shaped recesses are introduced into the conductor structure, creating a porous-like configuration that disrupts eddy current paths and reduces electromagnetic losses while allowing the conductor to maintain its electrical function
3Temperature
If conventional cooling concepts are designed to ensure thermal stability, then the temperature control is improved, but the device complexity and cost increase
Solution Approach 1:
The S-shaped and meandering configuration of the flat conductor creates cooling channels and fluid pathways as an inherent part of the conductor structure itself, allowing the conductor to serve both its electrical function and thermal management function without requiring separate complex cooling systems
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 enhances cooling efficiency and energy density while minimizing eddy currents, leading to improved thermal management and reduced electrical losses in high-demand applications.
Implementation Method 1
for the reduction of eddy currents, the flat conductor has, at least in regions, a plurality of layers that are insulated from one another and/or a plurality of slot-shaped recesses
Implementation Method 2
the coil core and serves for bundling of the magnetic flux that can be generated by means of the coil winding in order to thereby increase the inductance and/or the magnetic flux density of the coil
Implementation Method 3
The coil core is preferably composed of a magnetizable material
Implementation Method 4
the current heat losses ensuing in the electrical machine represent a significant and often also the predominant part of the total losses of the electrical machine
Data Source
AI summary
An electrical machine with a rotor and a stator. The rotor or the stator has at least one coil with a coil core and a coil winding, which surrounds the coil core. The coil winding has at least one turn that is formed from a flat conductor, which is bent a around a plurality of bending axes, which are spaced apart from one another and are parallel, and, as viewed in section, is S-shaped and/or has a meandering shape. The flat conductor has a plurality of layers that are insulated from one another, at least in regions, and/or a plurality of slot-shaped recesses.