Armature Winding Coil Replacement for Vibration Reduction
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Solution Overview
Problem
In rotating electrical machines, the increased voltage in armature windings leads to reduced reliability due to increased current density and insulation issues, and fractional-slot designs face challenges with electromagnetic excitation forces causing core vibration, making it difficult to detune natural vibration frequencies effectively.
Innovation Solution
The armature winding configuration involves replacing specific coil pieces between phases to minimize second-order and higher-order space harmonic components, reducing electromagnetic excitation forces and enhancing core stability by adjusting coil pitches and jumper wire placements, thereby reducing vibration and improving reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the voltage of armature winding is increased, then the machine capacity is increased, but the current density increases and insulation reliability decreases
Solution Approach 1:
The patent changes the winding configuration parameters by using fractional slots (54 slots for 4 poles) instead of integer slots, and by replacing specific coil pieces between phases. This modifies the space harmonic components of the magnetic flux density, thereby reducing electromagnetic excitation forces and improving reliability at high voltages without sacrificing machine capacity.
2Adaptability or versatility
If fractional slots are used to increase design flexibility, then the number of slots cannot be divided by poles and phases, but electromagnetic excitation forces cause core vibration
Solution Approach 1:
The patent applies local quality by selectively replacing only certain coil pieces (specifically, coil pieces at specific positions in the phase belt) between adjacent phases, rather than changing the entire winding configuration. This localized modification reduces second-order space harmonic components and electromagnetic excitation forces while maintaining the overall fractional-slot design flexibility.
Solution Approach 2:
The patent introduces asymmetry in the winding configuration by replacing coil pieces between phases in a non-uniform pattern. This asymmetric arrangement disrupts the symmetry that generates even-ordered space harmonics, thereby reducing electromagnetic excitation forces and core vibration while preserving design flexibility.
3Object-affected harmful factors
If coil pieces are replaced between phases, then second-order space harmonic components are reduced, but the winding configuration becomes more complex
Solution Approach 1:
The patent segments the winding modification into discrete, localized replacements of specific coil pieces between phases, rather than redesigning the entire winding configuration. This segmented approach reduces second-order space harmonic components while keeping the overall winding structure manageable and not excessively complex.
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 decreases electromagnetic excitation forces, reduces core vibration, and increases the reliability of the armature winding by minimizing second-order space harmonic components, leading to improved performance and reduced vibration in rotating electrical machines.
Implementation Method 1
a magnetic flux generated in a gap between an armature and a rotor generates an electromagnetic force to attract an armature core to a rotor
Implementation Method 2
a magnetic flux generated in a gap between an armature and a rotor generates an electromagnetic force
Implementation Method 3
an armature winding includes upper and lower coil pieces formed in two layers in slots provided in an armature core
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to one embodiment, there is provided a 3-phase 4-pole 2-layer armature winding (14) of a rotating electrical machine. A winding of each phase of the armature winding (14) forms a series coil. Each series coil includes upper coil pieces (15) and lower coil pieces (16) which are connected each other at a connection side coil end (19a) and a counter-connection side coil end (19b), the upper coil pieces (15) and lower coil pieces (16) being placed in 54 slots (13) provided in an armature core (12). At least one coil piece (22 or 23) of the upper and lower coil pieces (15, 16), provided in at least one of an innermost position and an outermost position from the center of a phase belt of each phase, is replaced with a coil piece (24 or 25) of an adjacent phase.