Adaptive Switching Mode Control for Rotary Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control systems for rotary machines frequently switch between modes to optimize current and torque control, leading to excessive switching frequency and potential degradation in control performance due to fixed threshold values for error ratio and power supply voltage variations.
Innovation Solution
A control system with an estimation section that calculates the required time period for a control amount to reach a predetermined value, allowing for adaptive update timing of switching modes based on estimated time periods, reducing unnecessary switching and maintaining control performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If model estimation control is used to optimize current and torque control by frequently switching modes, then transient-time follow-up characteristic is improved, but switching frequency becomes excessive leading to control performance degradation
Solution Approach 1:
The patent applies dynamics by making the switching mode update timing adaptive rather than fixed. The control apparatus dynamically adjusts when to update switching modes based on estimated time periods required for control amounts to reach predetermined values. This dynamic adjustment optimizes transient response while preventing excessive switching that would degrade control performance.
Solution Approach 2:
The patent changes the parameter of update timing from a fixed interval to a variable interval based on estimated time periods. By calculating how long it takes for control amounts (current, torque, magnetic flux) to reach predetermined values, the system adapts the switching frequency to actual system conditions, improving transient response without causing excessive switching.
2Measurement precision
If switching mode is updated frequently to respond to voltage variations and error changes, then control accuracy is improved, but unnecessary switching increases reducing system stability
Solution Approach 1:
The patent applies preliminary action by estimating the time period required for control amounts to reach predetermined values before actually updating the switching mode. This prediction allows the system to prepare for necessary switches while avoiding unnecessary ones, maintaining control accuracy without compromising stability through excessive switching.
Solution Approach 2:
The patent uses feedback by continuously monitoring control amounts (current, torque, magnetic flux) and comparing them against command values. The estimation section uses this feedback to calculate required time periods, and the update timing setting section adjusts switching mode updates based on these calculations, creating a closed-loop system that maintains accuracy while ensuring stability.
Data Source
AI summary
An estimation section estimates a time period required for a norm of a difference vector between a current flowing to a motor/generator and a command current to attain a threshold level r in each switching mode provisionally set by a mode setting section. A mode determination section determines the switching mode of the longest required time period to be a final switching mode. A drive section controls an inverter to operate in the switching mode determined by the mode switching section.