Voltage Angle Control for Permanent Magnet Machine
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Solution Overview
Problem
Permanent magnet machines face challenges in delivering high torque at high speeds and maintaining efficiency, particularly when driven by a battery, due to the requirement of a minimum voltage margin in d-q-axis current regulation, which limits their ability to utilize six-step mode operation.
Innovation Solution
The implementation of a flux vector control system that generates an output voltage angle with an angular canceling function, allowing the control signal to regulate the permanent magnet machine as a second-order quadrant-axis current, thereby simplifying current control and enabling operation at high torque and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If d-q-axis current regulation is used, then control precision is improved, but device complexity and voltage margin requirements increase, limiting high-speed operation
Solution Approach 1:
The patent extracts and eliminates the angular control portion from the dynamic response model, separating it from the control signal path. This allows the control system to operate without requiring voltage margin for angular control, simplifying the overall control architecture while maintaining precision through direct q-axis current regulation.
Solution Approach 2:
The patent changes the control parameter from traditional d-q-axis voltage regulation to direct q-axis current control with canceled angular dynamics. This parameter transformation eliminates the need for voltage margin in angular control, enabling high-speed operation with reduced complexity.
2Stability of the object's composition
If minimum voltage margin is maintained for d-q-axis regulation, then stability is improved, but torque production capability at high speeds deteriorates
Solution Approach 1:
The angular control portion is extracted and canceled from the system, allowing voltage to be fully utilized for torque production rather than being constrained by minimum voltage margin requirements for angular stability. This enables high-speed torque operation while maintaining stability through the simplified control approach.
3Loss of energy
If six-step mode operation is enabled, then efficiency is improved, but control precision and dynamic response deteriorate
Solution Approach 1:
The patent applies dynamic cancellation of the angular control portion, allowing the system to adapt between six-step mode and vector control modes. This dynamic approach enables efficient six-step operation while maintaining control precision through active compensation and regulation of the q-axis current.
Data Source
AI summary
For flux vector control, a controller generates a control signal for a permanent magnet machine. The controller further generates an output voltage angle as a function of the control signal that regulates the permanent magnet machine. The output voltage angle includes an angular canceling function that cancels an angular control portion of a dynamic response of the permanent magnet machine such that the control signal controls the permanent magnet machine as a second-order quadrant-axis current.