Variable Primary Magnetic Flux Control for Rotary Electric Motors
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Solution Overview
Problem
In primary magnetic flux control of rotary electric motors, existing methods struggle to efficiently control the current phase and achieve maximum torque/current control, especially when torque fluctuations occur, as they typically operate with a constant primary magnetic flux amplitude.
Innovation Solution
A method is introduced where the primary magnetic flux command value is adjusted based on the torque to control the current phase, minimizing the armature current amplitude and allowing the rotary electric motor to operate at an efficient point by setting the primary magnetic flux amplitude to its minimum value corresponding to the torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the primary magnetic flux amplitude is kept constant in primary magnetic flux control, then the control system is simple to operate, but the current phase cannot be efficiently controlled and maximum torque/current control cannot be achieved when torque fluctuates
Solution Approach 1:
The invention applies the dynamics principle by making the primary magnetic flux amplitude variable rather than constant. The control system dynamically adjusts the primary magnetic flux amplitude based on the detected torque level, allowing the system to transition from a static control mode to a dynamic one. This enables the motor to operate at optimal efficiency points across different torque conditions while maintaining relatively simple control architecture.
Solution Approach 2:
The invention implements parameter changes by modifying the primary magnetic flux amplitude parameter according to torque variations. Instead of keeping this parameter fixed, the system changes it adaptively based on operating conditions, specifically adjusting the amplitude to achieve desired current phase control and maximum torque/current control at different torque levels.
2Productivity
If the primary magnetic flux amplitude is adjusted according to torque to achieve maximum torque/current control, then the motor operates efficiently, but the control system becomes more complex
Solution Approach 1:
The invention applies feedback by using the detected torque information to adjust the primary magnetic flux amplitude. The torque detection result feeds back to the control system, which then modifies the magnetic flux amplitude accordingly. This closed-loop feedback mechanism enables efficient torque/current control without requiring complex predictive models or extensive computational resources.
Solution Approach 2:
The control system implements self-service by automatically adjusting the primary magnetic flux amplitude based on torque detection without requiring external intervention or complex control algorithms. The system serves itself by using its own operational parameters (torque) to optimize its control settings (magnetic flux amplitude), reducing the need for additional control complexity.
3Manufacturing precision
If the primary magnetic flux command value is changed according to torque, then the current phase is properly controlled, but the control algorithm becomes more complicated
Solution Approach 1:
The invention uses parameter changes to improve current phase control precision by adjusting the primary magnetic flux amplitude based on torque. This approach modifies a key control parameter (amplitude) in response to operating conditions, achieving better phase control without fundamentally changing the control algorithm structure or requiring complex computational methods.
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 enables proper control of the current phase and achieves maximum torque/current control by minimizing the armature current while maintaining constant torque, allowing the motor to operate efficiently and effectively.
Implementation Method 1
a field flux Λ0 that the field generates and a magnetic flux (λa: id·Ld, iq·Lq) of an armature reaction generated by an armature current (ia) flowing in an armature
Implementation Method 2
a torque T of the rotary electric motor can be controlled in proportion to the yc-axis component iyc of the amplitude ia of the armature current
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a technique for driving a rotary electric motor at an efficient operating point in accordance with a torque by changing a primary magnetic flux command value in accordance with the torque to thereby control a current phase properly in primary magnetic flux control. With respect to a certain torque T, when an amplitude Λδ of a primary magnetic flux takes a value λδ0(T), an amplitude ia of an armature current is minimized. At this time, maximum torque/current control is enabled. Thus, the value λδ0(T) is employed as the amplitude of the primary magnetic flux command value to perform the primary magnetic flux control, whereby the armature current is automatically decided. That is, a current phase P is uniquely decided. In short, the current phase P is controlled to be a desired phase in accordance with the torque T, so that the rotary electric motor is driven at the efficient operating point in accordance with the torque.