Turnable Rotor Subsegments for High-Speed Motor Flux Control
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Solution Overview
Problem
Conventional electrical machines with permanent magnet rotors experience high induced voltages at high rotation speeds, leading to potential damage and inefficiency due to the need for field weakening, which limits their operational range.
Innovation Solution
The electrical machine incorporates a rotor with at least three subsegments, where two subsegments can be turned relative to each other using a turning device, allowing their magnetic effects to cancel out above a predetermined speed threshold, with a third subsegment determining the overall magnetic design, thereby reducing induced voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the electrical machine operates at high rotation speeds, then the power output increases, but high induced voltages are generated which can damage the electronics
Solution Approach 1:
The rotor is divided into multiple rotor subsegments (at least three) that can be independently positioned. This segmentation allows the magnetic pole arrangements to be selectively activated or deactivated, enabling the machine to operate at high speeds by canceling out induced voltages through strategic positioning of opposite magnetic poles, thus resolving the contradiction between power output and induced voltage damage
Solution Approach 2:
Instead of accepting high induced voltages as an inevitable consequence of high-speed operation, the invention inverts the approach by using the rotor subsegments to generate opposing magnetic fields that actively cancel out the harmful induced voltages. This allows the machine to operate at high speeds without the damaging voltage effects that would normally occur
2Speed
If field weakening is carried out by rotation of partial rotors, then the machine can operate at high rotation speeds, but induced voltages must be compensated with high current which reduces efficiency
Solution Approach 1:
The rotor is segmented into multiple independently controllable subsegments, allowing selective positioning of magnetic poles. This enables the system to achieve high-speed operation by canceling induced voltages through geometric arrangement of opposite poles rather than through energy-intensive field weakening, thus reducing energy loss while maintaining high rotation speeds
Solution Approach 2:
The invention changes the geometric parameter of rotor subsegment positioning rather than changing the magnetic field strength through current adjustment. By rotating subsegments to specific angular positions where opposite poles face each other, the system reduces induced voltages through spatial configuration instead of energy-consuming electrical compensation, thereby reducing energy loss at high speeds
3Adaptability or versatility
If the rotor has two or more axially segmented partial rotors that can be displaced, then field weakening can be achieved, but the configuration is complex and can be used only to a limited extent in high rotation speed ranges
Solution Approach 1:
The rotor is divided into a manageable number of subsegments (at least three, with at least two being turnable) that can be independently positioned. This segmentation provides the flexibility needed for high-speed operation through magnetic field cancellation while keeping the structure simpler than fully axially segmented designs, thus achieving a balance between adaptability and complexity
Solution Approach 2:
The rotor subsegments are designed to be dynamically repositionable during operation, allowing the system to adapt to different operating conditions. The turnable subsegments can be rotated to optimal positions for high-speed operation, providing versatility while maintaining a relatively simple fixed structure for the majority of the rotor, thus resolving the contradiction between adaptability and complexity
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 allows the electrical machine to operate safely at high speeds by substantially canceling out magnetic fields, preventing damage and reducing the need for high current compensation, thus enhancing efficiency and preventing mechanical unbalances.
Implementation Method 1
this generates induced voltages which have to be compensated for with a correspondingly high current
Implementation Method 2
effects of the at least two rotor subsegments which can be turned relative to one another may substantially completely cancel each other out
Data Source
AI summary
The electrical motor includes a stator and a rotor configured to be rotated about an axis wherein the rotor includes at least three rotor subsegments, wherein a first and second rotor subsegment can be turned relative to one another about the axis in response to a rotation speed range being above a predetermined threshold value of a rotation speed of the electrical machine.