Stator Coil Winding for Inverter Surge Voltage Resistance
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Solution Overview
Problem
Conventional rotating electrical machines below 1 kVrms lack effective measures to handle steep surge voltage from inverter devices, leading to increased size due to insulation thickness and coil diameter changes, and difficulty in voltage balance due to the use of round wire with enamel coating.
Innovation Solution
The solution involves winding conductive wire in multiple layers close together within the stator core, increasing the combined capacitance between wires to reduce voltage concentration and balance voltage across coils without changing the machine's output properties, using a manufacturing method that winds the wire reciprocally on a spool to maintain proximity and reduce voltage at coil ends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation thickness is increased to handle surge voltage, then insulation resistivity is improved, but machine size increases
Solution Approach 1:
The patent changes the electrical parameter (capacitance) by altering the physical arrangement of coil winds. By winding conductors in a specific pattern with controlled spacing, the distributed capacitance is increased, which changes the voltage distribution characteristics during surge events, thereby improving insulation resistivity without increasing physical insulation thickness or machine size.
Solution Approach 2:
The patent addresses the insulation problem by moving from a spatial dimension solution (thicker insulation) to an electrical dimension solution (distributed capacitance arrangement). The winding structure is designed to create specific electrical field distributions that naturally balance voltage stress, resolving the contradiction without adding physical volume.
2Reliability
If coil diameter is increased to handle surge voltage, then insulation resistivity is improved, but machine size increases
Solution Approach 1:
The patent modifies the electrical parameters of the coil system by designing a specific winding arrangement that increases distributed capacitance. This electrical parameter change allows the system to withstand surge voltage through voltage balancing rather than increasing coil diameter, thus maintaining compact machine size while improving insulation resistivity.
3Reliability
If voltage distribution between coils is improved, then surge voltage resistance is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent divides the coil winding into multiple segments or sections with specific spacing arrangements. This segmentation creates distinct capacitance zones that collectively achieve the desired voltage distribution. The segmented approach allows for systematic manufacturing while achieving the complex electrical performance required for surge voltage resistance.
4Reliability
If distributed capacitance between coils is increased, then voltage concentration is reduced, but coil structure complexity increases
Solution Approach 1:
The patent achieves increased distributed capacitance through controlled physical spacing and winding patterns rather than adding complex structural elements. By adjusting parameters such as wire spacing, winding density, and layer arrangement, the capacitance is optimized while maintaining a relatively simple coil structure that can be manufactured using conventional techniques.
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 approach enhances insulation resistivity and reduces voltage concentration, maintaining machine output while minimizing size increases, and improves anti-inverter-surge properties without needing additional insulation sheets.
Implementation Method 1
the combined capacitance of the conductive wires in the coil mounted to the core is great
Data Source
AI summary
A stator coil is configured of a first group of six turns of conductive wire, and a second group also of six turns, with the first group of six turns being wound on a spool, leaving a gap the same as the diameter of the conductive wire between winds. Upon completion of winding the first group, the winding is turned back, and the second group of six turns is wound in the gap, so as to be adjacent to the turns of the first group. The article is then inserted into a slot in a stator core of a stator, thereby configuring a stator coil. This provides for a rotating electrical machine and manufacturing method thereof with improved insulation resistivity regarding inverter surge voltage, and moreover high output can be obtained with a machine of comparable external dimensions with conventional machines.