AC Rotary Machine Control Device Resistance Error Compensation
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Solution Overview
Problem
AC rotary machines face smooth operation challenges due to resistance value errors caused by temperature changes, leading to vibration and position fixation issues, as existing methods complicate the estimation of actual resistance values.
Innovation Solution
A control device that includes a temperature detection unit and a resistance value estimation unit, calculating an estimated resistance value by adding a correction value to a basic estimated resistance value, which is a sum of a fixed value and a value proportional to the external temperature, to account for temperature-dependent resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a model resistance value is used for control, then the control system is simple, but the AC rotary machine cannot rotate smoothly due to temperature-induced resistance errors
Solution Approach 1:
The patent applies parameter changes by transforming the temperature parameter into a resistance value parameter. The temperature model unit converts external temperature into an estimated resistance value that reflects actual winding resistance at different temperatures. This allows the control system to adapt to temperature-induced resistance changes without increasing overall system complexity, resolving the contradiction between simple control and smooth rotation performance.
2Reliability
If the actual resistance value is accurately estimated using external temperature transformation, then smooth rotation is achieved, but the estimation method becomes complicated
Solution Approach 1:
The patent introduces a temperature model unit as an intermediary component that transforms external temperature measurements into estimated resistance values. This intermediary handles the complex temperature-to-resistance transformation logic centrally, allowing individual control units to use simple resistance values without implementing complex estimation algorithms themselves. This reduces overall system complexity while maintaining accurate resistance estimation for smooth rotation.
Solution Approach 2:
The temperature model unit performs preliminary transformation of temperature data into resistance values before the control units need them. By pre-calculating and providing estimated resistance values based on external temperature, the system avoids the need for each control unit to perform complex real-time temperature-to-resistance transformations, thereby simplifying the estimation method implementation across the system.
3Reliability
If resistance value error exceeds allowable range, then vibration and position fixation occur, but maintaining tight tolerance increases system complexity
Solution Approach 1:
The patent implements feedback by continuously monitoring external temperature through the temperature model unit and adjusting the estimated resistance value accordingly. This feedback mechanism ensures that resistance value errors remain within allowable ranges by compensating for temperature-induced variations in real-time. The feedback approach maintains operational stability without requiring complex error compensation systems, as the temperature-based estimation proactively prevents error accumulation.
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 configuration allows the AC rotary machine to rotate smoothly with a simpler method, ensuring the resistance value error falls within an allowable range that prevents vibration and position fixation, enhancing operational stability.
Implementation Method 1
an actual resistance value of the AC rotary machine, which changes depending on temperature of the AC rotary machine
Data Source
AI summary
When there is an error between an actual resistance value of an AC rotary machine (ACRM) and an estimated resistance value estimated from a detected external temperature of the ACRM, the ACRM cannot be rotated smoothly. In view of this, provided are a control device for an ACRM and the like, including a resistance value estimation unit (10) configured to calculate an estimated resistance value (Rest) by adding to a basic estimated resistance value (Rest0), which is a value obtained by estimating a resistance value from a detected external temperature of the ACRM, an estimated resistance correction value (Radd), which is determined such that a range that can be taken by an error (ΔR) of the resistance value estimated in advance falls within a range of the error of the resistance value that enables the ACRM to be rotated smoothly.