Variable Magnetic Flux Rotary Machine Bypass Paths
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Solution Overview
Problem
Variable magnetic flux-type rotary electric machines face challenges in controlling magnetic flux linkage, leading to energy losses during low load and high-speed rotation, and ohmic losses due to demagnetization and magnetization currents, which restrict design and usage.
Innovation Solution
The implementation of magnetic flux bypass paths between adjacent magnetic poles in the stator armature action reduces magnetic flux leakage, allowing for increased torque generation during high load conditions without changing the magnetization state of the permanent magnets, thereby minimizing energy losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If magnets with small coercive field strengths are used to control magnetic forces, then control of magnetized state becomes possible, but demagnetization due to armature counteraction occurs and design is restricted
Solution Approach 1:
A magnetic flux bypass path is introduced as an intermediary element between adjacent magnetic poles. This bypass path provides a controlled route for magnetic flux to flow, preventing direct armature counteraction on the permanent magnets. The bypass path acts as a mediator that allows magnetic flux to be redirected away from the magnets during certain operating conditions, thereby preventing demagnetization while maintaining control capability.
2Productivity
If conventional rotary electric machines operate during low load conditions, then basic function is maintained, but energy loss increases
Solution Approach 1:
The magnetic flux distribution in the machine is made dynamic through the bypass path configuration. During low load conditions, the bypass path allows magnetic flux to be redirected, dynamically adjusting the flux distribution to reduce losses. This dynamic flux management enables the machine to operate efficiently across varying load conditions by adaptively controlling magnetic flux pathways.
3Speed
If conventional rotary electric machines operate during high-speed rotation, then speed requirement is met, but energy loss increases
Solution Approach 1:
The magnetic flux bypass path serves as an intermediary that becomes particularly effective during high-speed rotation. By providing an alternative flux pathway, it reduces the armature counteraction effects that are magnified at high speeds, thereby reducing energy losses while maintaining the required rotational speed performance.
4Loss of energy
If magnetic flux bypass paths are formed to inhibit magnetic flux leakage, then loss during low load and high-speed rotation is inhibited, but device complexity increases
Solution Approach 1:
The magnetic flux bypass paths are merged with the existing stator structure, integrating the loss-reduction function into the conventional machine architecture. By combining the bypass path functionality with the stator design, the solution achieves energy loss reduction without proportionally increasing device complexity, as the bypass paths utilize existing structural elements and materials.
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 enhances energy efficiency by reducing energy consumption during low load conditions and increasing torque at high loads, improving the performance of electric vehicles as electric motors while using magnets with low coercive field strength without additional energy loss.
Implementation Method 1
forming magnetic flux bypass paths that can inhibit the amount of magnetic flux leakage due to the stator armature action between adjacent magnetic poles
Implementation Method 2
the pathway for the magnetic flux of the magnet inside the rotor is inhibited by armature current without changing the magnetization condition of the permanent magnet
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A variable magnetic flux-type rotary electric machine includes a stator (11) and a rotor (12). The stator (1 1) includes a stator coil (C) wound on teeth. The rotor (12) defines an air gap between the rotor (12) and the stator (1 1). The rotor (12) has at least one permanent magnet (m) arranged in the d-axis magnetic path. The stator (11) and the rotor (12) are arranged relative to the permanent magnet (m) to set a characteristic of d(Kt(I))/dI >= 0 in a range of at or below magnetic saturation of a core material of at least one of the stator (11) and the rotor (12), where KT represents a torque constant, and I represents an applied current, and a function of KT with respect to I is represented by KT = Kt(I) for a torque Tr acting on the rotor (12) that is represented by Tr = KT x I.