Inverter Control Device Torque Accuracy Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inverters configured to drive synchronous reluctance motors with low magnetic flux face challenges in accurately calculating current amplitude commands based on torque commands, leading to discrepancies between intended and actual torque output.
Innovation Solution
An inverter control device comprising a current detector, vector converter, current amplitude command calculator, dq-axes converter, and current controller, which calculates current amplitude and phase angle commands to generate torque commands accurately, ensuring the motor output torque aligns with the torque command, while minimizing interference between speed control and current phase angle changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If arithmetic expressions or maps are used to calculate current amplitude command from torque command, then the control structure is simple, but the torque output accuracy deteriorates
Solution Approach 1:
The patent introduces a feedback mechanism where the calculated current amplitude command is validated against the torque command through a torque calculation unit. The system continuously monitors the torque output and adjusts the current amplitude command to ensure accuracy, resolving the contradiction between simple control structure and accurate torque output.
Solution Approach 2:
The patent replaces traditional mechanical control methods with an electromagnetic field-based control approach. By using magnetic flux detection and electromagnetic calculations to determine current amplitude commands, the system achieves higher torque accuracy without significantly increasing mechanical complexity.
2Use of energy by moving object
If current phase angle is adjusted to optimize motor performance, then motor efficiency is improved, but interference with speed control increases
Solution Approach 1:
The patent implements a dynamic current phase angle adjustment mechanism that adapts to changing operating conditions. The system continuously optimizes the current phase angle based on real-time motor state while incorporating damping mechanisms to prevent excessive oscillations, thereby maintaining both efficiency and control stability.
Solution Approach 2:
The patent changes the current phase angle parameter dynamically based on motor operating conditions such as speed and load. By adjusting this parameter in response to changing conditions rather than keeping it fixed, the system improves efficiency without causing instability in the overall control system.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An inverter control device according to an embodiment configured to generate a current amplitude command by which the output torque of the motor is set in accordance with the torque command and includes an inverter main circuit; a current detector for detecting a current response output from the inverter main circuit; a vector converter for converting the current response into a d-axis current and a q-axis current by using a rotational phase angle of a motor connected to the inverter main circuit; a current amplitude command calculator for calculating, based on a torque command and a current phase angle command, a current amplitude command of the current response output from the inverter main circuit; a dq-axes converter for calculating a d-axis current command and a q-axis current command from the current amplitude command and the current phase angle command; and a current controller for calculating a voltage command so that the d-axis current command and the q-axis current command are equal to the d-axis current and the q-axis current.