Electric Machine Stator Winding for High Magnetomotive Force
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Solution Overview
Problem
Electric machines face inefficiencies at higher frequencies due to skin effects in stator bars, and increasing phase currents to enhance magnetomotive force leads to higher costs or larger power electronics volumes.
Innovation Solution
The electric machine design features a stator with a concentrated winding comprising multiple coils wound around teeth, each connected to its own power supply, allowing for independent phase current control and generation of multiple rotary fields with different pole pairs, which increases the magnetomotive force without significantly increasing power electronics volume or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If phase currents are increased to enhance magnetomotive force, then the magnetomotive force is improved, but power electronics volume and cost increase
Solution Approach 1:
The stator winding is segmented into multiple independent coils (first coil, second coil, third coil, etc.) each connected to separate power supply units. This segmentation allows independent control of phase currents in each coil, enabling optimized current distribution that enhances magnetomotive force without requiring uniform high currents across all coils, thus reducing overall power electronics requirements
Solution Approach 2:
The invention changes the operational parameters by allowing different phase currents to flow through different coils simultaneously. By adjusting the current magnitude and phase angle in each coil independently, the system can generate enhanced magnetomotive force through constructive interference of magnetic fields while maintaining lower individual current levels, reducing power electronics volume and cost
2Force
If phase currents are increased to enhance magnetomotive force, then the magnetomotive force is improved, but power electronics cost increases
Solution Approach 1:
The stator winding is divided into multiple independent coils (first coil, second coil, third coil, etc.) each connected to separate power supply units. This segmentation allows independent control of phase currents in each coil, enabling optimized current distribution that enhances magnetomotive force without requiring uniform high currents across all coils, thus reducing overall power electronics requirements
Solution Approach 2:
The invention changes the operational parameters by allowing different phase currents to flow through different coils simultaneously. By adjusting the current magnitude and phase angle in each coil independently, the system can generate enhanced magnetomotive force through constructive interference of magnetic fields while maintaining lower individual current levels, reducing power electronics volume and cost
3Speed
If skin effects occur in stator bars at higher frequencies, then frequency operation is enabled, but losses increase
Solution Approach 1:
The stator winding is segmented into multiple independent coils with separate power supply connections. This segmentation transforms the traditional bar winding structure into discrete coil structures, allowing each coil to be optimized for high-frequency operation. The independent coil structure reduces skin effect losses by enabling better current distribution and reducing the effective path length for high-frequency currents
Solution Approach 2:
The invention enables dynamic control of phase currents in each coil independently through separate power supply units. This dynamic control allows the system to adapt current distribution to operating conditions, optimizing performance at higher frequencies by adjusting phase angles and magnitudes to minimize skin effect losses while maintaining effective magnetomotive force generation
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 the efficiency of electric machines by increasing the maximum current per groove, allowing for a higher magnetomotive force and optimizing parameters like cogging torque, power density, and noise suppression without increasing power electronics volume or cost.
Implementation Method 1
The stator winding can be connected to a power electronics and designed to generate a rotary field
Implementation Method 2
Electric machines can operate as a motor or as a generator, wherein electrical energy is converted into kinetic energy or vice versa
Data Source
AI summary
An electric machine (21) having a stator (20) and having a rotor (29) rotatably mounted to the stator (20) is specified. The stator (20) comprises a stator winding (24), at least three teeth (23), and at least three grooves (22). In each case, one tooth (23) of the stator (20) is arranged between two grooves (22) along a circumference of the stator (20), and the stator winding (24) has at least three coils (25), wherein each of the coils (25) is wound around a tooth (23) of the stator (20), so that the stator winding (24) is a concentrated winding. In addition, the winding direction of all coils (25) is the same, each of the coils (25) is designed to be fed with its own phase current, and the stator (20) is designed to generate at least two rotary fields having different numbers of pole pairs independently of each other, in particular simultaneously. In addition, an activation unit (40) for the electric machine (21) and a method for operating an electric machine (21) are specified.