Dual-Winding Rotary Electric Machine for Torque Ripple Suppression
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Solution Overview
Problem
Conventional rotary electric machines with toothless and slotless stator cores experience increased vibration and noise due to non-uniform magnetic flux waveforms, leading to cogging torque and torque ripple.
Innovation Solution
The rotary electric machine employs a toothless and slotless stator core with an armature winding comprising two electrically independent systems, where the current control device differentiates current waveforms based on the radial distance from the field element to approximate torque waveforms to a sinusoidal shape, reducing peak values and torque ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a toothless and slotless stator core is used, then manufacturing simplicity and reduced cogging torque are achieved, but magnetic flux waveform uniformity deteriorates leading to increased vibration and noise
Solution Approach 1:
The patent applies local quality by differentiating current waveforms for different radial positions. The armature winding is divided into first and second systems at different radial distances from the field element, with each system receiving differentiated current control to compensate for local magnetic flux waveform non-uniformity, thereby reducing vibration and noise while maintaining the simple toothless and slotless stator core structure
Solution Approach 2:
The patent changes the current waveform parameters based on radial position. The current control device differentiates current waveforms between the first and second armature winding systems according to their respective radial distances from the field element, adjusting current parameters to compensate for magnetic flux non-uniformity and reduce harmful vibrations and noise
2Object-affected harmful factors
If differentiated current control is applied to armature windings at different radial distances, then torque waveform sinusoidality and vibration reduction are improved, but control system complexity increases
Solution Approach 1:
The patent segments the armature winding into two electrically independent systems based on radial position. The first armature winding system is arranged closer to the field element than the second armature winding system, allowing independent current control for each segment to achieve sinusoidal torque waveforms while managing control complexity through modular segmentation
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 configuration results in low vibration and noise operation by suppressing torque ripple and enabling efficient torque output across varying rotation speeds.
Implementation Method 1
a rotary electric machine includes a field element having a plurality of magnetic poles and an armature including an armature winding
Data Source
AI summary
An armature winding of a rotary electric machine includes two systems of electrically independent windings. An armature winding of a first system is closer to the field element in the radial direction than an armature winding of a second system, A current control device is provided for controlling a current to the armature winding of the first system and the armature winding of the second system. In consideration of a difference in magnetic flux waveforms from the field element caused by a difference in the distance to the field element in the radial direction, the current control device differentiates a current waveform to the armature winding of the first system from a current waveform to the armature winding of the second system.