AC Motor Control Apparatus High-Order Vector Phase Alignment
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Solution Overview
Problem
Existing AC motor control technologies face instability due to phase differences between high-order voltage and current vectors, which can lead to motor control instability, especially in polyphase AC motors with non-uniform rotor magnetization and stator shapes.
Innovation Solution
An AC motor control apparatus with an inverter and current controller that performs fundamental wave and high-order current control, using high-order voltage command calculation and vector transformation sections to rotate and adjust high-order vectors, ensuring phase coincidence between high-order voltage and current vectors, thereby stabilizing motor control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If feedback control is applied to high-order current components in the same manner as fundamental wave current control, then high-order current control can be implemented, but phase difference between voltage and current vectors causes control instability
Solution Approach 1:
The patent applies dynamic adjustment by calculating a phase difference between the high-order voltage vector and high-order current vector, then dynamically rotating the high-order voltage vector to match the current vector's phase. This dynamic phase alignment resolves the instability caused by fixed-phase feedback control while maintaining high-order current control capability.
Solution Approach 2:
The patent changes the phase parameter of the high-order voltage vector through rotation transformation. By adjusting the phase angle based on the calculated phase difference, the system transforms the voltage vector to achieve phase coincidence with the current vector, thereby stabilizing control without sacrificing automation extent.
2Measurement precision
If high-order dq transformation is applied to convert high-frequency components to direct current, then high-order current control becomes possible, but phase misalignment between voltage and current vectors deteriorates control performance
Solution Approach 1:
The patent uses feedback by calculating the phase difference between the high-order voltage vector and high-order current vector obtained through high-order dq transformation. This feedback mechanism enables real-time detection of phase misalignment and triggers corrective rotation of the voltage vector to maintain phase coincidence and control stability.
Solution Approach 2:
The system dynamically adjusts the phase of the high-order voltage vector based on real-time phase difference calculations. This dynamic rotation ensures that even when high-order dq transformation reveals precise current components, the phase misalignment problem is continuously corrected to maintain stable control.
Data Source
AI summary
A current controller calculates a drive signal by means of fundamental wave current control and high-order current control, for driving an inverter. A 5th order/7th order voltage command calculation section calculates a 5th order/7th order voltage command vector Vdk*, Vqk* by means of feedback control which makes a high-order dq transformation value extracted from the actual current coincide with a 5th order/7th order current command value Idk*, Iqk*. A 5th order/7th order vector transformation section executes high-order vector transformation processing on the 5th order/7th order voltage command vector Vdk*, Vqk* that is calculated by the 5th order/7th order voltage command calculation section, with the high-order vector transformation processing being executed such as to make a high-order voltage vector and a high-order current vector coincide in phase in high-order dq coordinates, and with the high-order vector transformation processing including rotation transformation by high-order vector rotation which rotates a high-order vector.