Stator Coil Layout for Flashover-Resistant Fast Pulse Operation
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Solution Overview
Problem
Existing stators in electric machines experience dangerous potential differences between adjacent stator coils due to high edge steepness voltage pulses, leading to risk of electrical flashover, particularly at the end faces or winding overhangs.
Innovation Solution
Adjacent stator coils of the same phase are wound in opposite directions and connected in parallel, with radially aligned electrical conductors extending in the same direction, ensuring the potential difference remains zero or near-zero during fast voltage pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If voltage pulses with high edge steepness are supplied to the stator winding, then the power and switching speed of the electrical machine are improved, but dangerous potential differences occur between adjacent stator coils leading to electrical flashover risk
Solution Approach 1:
The patent applies the equipotentiality principle by configuring adjacent stator coils of the same phase to have radially aligned electrical conductors extending in the same direction. This arrangement ensures that during fast voltage pulses, the potential difference between adjacent coils remains zero or near-zero at corresponding radial positions, effectively creating an equipotential condition that prevents electrical flashover while allowing high power and switching speed operation
Solution Approach 2:
The patent employs asymmetry by winding adjacent stator coils of the same phase in opposite directions while maintaining radial alignment of their electrical conductors. This asymmetric winding configuration ensures that voltage pulses propagate in the same direction through both coils, synchronizing the potential distribution and eliminating dangerous potential differences between adjacent coils
2Use of energy by moving object
If adjacent stator coils are electrically connected in parallel for improved current distribution, then the electrical efficiency is improved, but the risk of potential difference and electrical flashover increases due to wave phenomena
Solution Approach 1:
By arranging radially aligned electrical conductors in parallel-connected adjacent stator coils, the patent creates equipotential conditions during transient voltage events. This ensures that even though coils are electrically connected in parallel for improved efficiency, the synchronized potential distribution prevents dangerous potential differences and maintains reliability
Solution Approach 2:
The patent merges the benefits of parallel electrical connection (improved current distribution and efficiency) with the protection of radial alignment (eliminated potential differences). This combination allows adjacent coils to be electrically connected in parallel while maintaining safety against electrical flashover through the synchronized propagation of voltage pulses
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A stator (5) for an electric machine (1) is described, comprising an annular stator body (7) with inwardly open stator slots (13, 13a, 13b) and stator coils (14a, 14b) of a stator winding (8) arranged in the stator slots (13, 13a, 13b), which are assigned to several phases (L1..L3) of the electric machine (1). Adjacent stator coils (14a, 14b) of the same phase (L1..L3) are wound in opposite directions and electrically connected in parallel. Furthermore, an electric machine (1) with such a rotor (3a..3c) is described, as well as a drive arrangement and a vehicle (17) with such an electric machine (1).