Synchronous Double Stator Machine Electrical Shift Compensation
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Solution Overview
Problem
Mechanical shifting of stators in synchronous double stator electric machines reduces cogging torque but leads to loss of magnetization, resulting in reduced power and torque performance, especially under loaded conditions.
Innovation Solution
Implementing an electrical shift in the control of mechanically shifted electric machines to compensate for the loss of magnetization by rotating the magnetic flux opposite to the mechanical shift, rebalancing power and torque between the machines to restore load angles and harmonics to their un-shifted topology values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If mechanical shifting of stators is implemented to reduce cogging torque, then cogging torque is minimized, but power and torque performance are reduced due to loss of magnetization
Solution Approach 1:
The patent applies parameter changes by adjusting the electrical control parameters (current magnitude, voltage, frequency) to compensate for the performance loss caused by mechanical stator shifting. The controller modifies operating parameters to restore magnetization levels and maintain power/torque output while preserving the cogging torque reduction benefits of the mechanical shift configuration.
Solution Approach 2:
The patent implements feedback control by continuously monitoring the actual power and torque output of the synchronous double stator electric machine and using this information to dynamically adjust the electrical control parameters. This closed-loop feedback system ensures that performance losses from mechanical shifting are compensated in real-time, maintaining optimal power and torque delivery across varying operating conditions.
2Object-generated harmful factors
If mechanical shifting of stators is implemented to reduce cogging torque, then cogging torque is minimized, but magnetization is lost
Solution Approach 1:
The patent changes electrical parameters (current magnitude, voltage, frequency) to compensate for magnetization loss. By adjusting these parameters, the system restores the magnetic field strength to acceptable levels while maintaining the mechanical shift configuration that reduces cogging torque.
Solution Approach 2:
The patent uses feedback control to monitor magnetization levels and dynamically adjust electrical control parameters to maintain reliable magnetic field strength. This ensures that magnetization remains within acceptable ranges despite the mechanical shifting of stators.
3Object-generated harmful factors
If mechanical shifting of stators is implemented to reduce cogging torque, then cogging torque is minimized, but the synchronous double stator electric machine performance is reduced
Solution Approach 1:
The patent applies parameter changes by adjusting electrical control settings to compensate for performance reduction. This allows the system to maintain productivity and machine performance while benefiting from the reduced cogging torque achieved through mechanical stator shifting.
Solution Approach 2:
The patent implements feedback control to monitor overall machine performance and dynamically adjust electrical parameters to maintain optimal productivity. This ensures that performance losses from mechanical shifting are compensated in real-time.
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 maintains performance by partially compensating for the loss of magnetization due to mechanical shifting, ensuring the power and torque remain balanced and cogging torque is minimized across the operational range.
Implementation Method 1
The electrical control may be configured to rotate the magnetic flux of the stator in a direction opposite to the mechanical shift
Implementation Method 2
The cogging torque of the first electric machine and the cogging torque of the second electric machine will in such case be in an opposite phase due to the shift of half slot pitch between the first stator and the second stator
Data Source
AI summary
A method for controlling a synchronous double stator electric machine. A first stator and a first set of magnetic poles on a common rotor forms a first electric machine. A second stator and a second set of magnetic poles on the rotor forms a second electric machine. The first electric machine and the second electric machine is shifted mechanically by a predetermined angle. An electrical shift is produced to the control of at least the mechanically shifted electric machine with a respective frequency converter in order to at least partly compensate for the mechanical shift in the mechanically shifted electric machine.