Asynchronous Machine Flux Control for Loss-Minimized Operation

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Solution Overview

Problem

Existing control and regulation methods for asynchronous machines are inefficient, leading to suboptimal energy usage and increased losses due to varying load conditions.

Innovation Solution

A method and device for determining the flux of an asynchronous machine using a model to minimize losses by adjusting the magnetic flux within a range of 50% to 120% of the rated flux, considering various loss components and utilizing existing parameters without iterative calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional control methods are used for asynchronous machines, then the machine can operate at different operating points, but energy efficiency is suboptimal and losses increase due to varying load conditions

Engineering Contradiction:
Improveenergy lossesVSAvoidoperational efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies dynamics by making the magnetic flux adaptive rather than fixed. The control system continuously adjusts the magnetic flux level based on real-time load conditions, transitioning from a static flux value to a dynamic one that optimizes efficiency across varying operational demands. This resolves the contradiction by enabling the system to maintain optimal efficiency (improving productivity) while adapting flux to minimize losses (reducing energy losses) under different load conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the magnetic flux parameter according to load conditions. The control system calculates optimal flux values based on the relationship between load, frequency, and flux, then adjusts the flux parameter dynamically. This allows the system to reduce energy losses (improving the first feature) while maintaining or enhancing operational efficiency (improving the second feature) through intelligent parameter adaptation rather than conventional fixed-parameter control.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the magnetic flux is adjusted to minimize losses, then energy efficiency improves, but complex iterative calculations are required

Engineering Contradiction:
Improvepower lossesVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent extracts the complex iterative calculation process from the control system by using a pre-established analytical relationship between load, frequency, and optimal flux. Instead of performing iterative optimizations in real-time, the system uses a direct calculation approach based on extracted key parameters and their relationships. This reduces control system complexity (improving the second feature) while maintaining the ability to minimize power losses (improving the first feature).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies preliminary action by pre-determining the optimal flux relationships through offline analysis and establishing analytical formulas before real-time operation. The complex optimization work is performed in advance to create simplified lookup relationships that can be quickly applied during actual control. This eliminates the need for complex real-time iterative calculations (reducing control system complexity) while ensuring optimal loss minimization (maintaining energy efficiency improvement).

Inventive Principle:
Principle #10Preliminary action

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 approach allows for efficient operation by reducing losses, optimizing efficiency, and improving energy usage without requiring new motor parameters or extensive computation time.

Implementation Method 1

an asynchronous machine (1), wherein a power converter (3) with a power converter control unit (30) is connected to the asynchronous machine (1)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3652854B2Energy efficient asynchronous machine
Publication Date: 2026.03.18 SIEMENS AG
  • EP3652854B2 patent drawingFigure 1
  • EP3652854B2 patent drawingFigure 2a~2e
  • EP3652854B2 patent drawingFigure 3

AI summary

In a method for determining a flux (4) of an asynchronous machine (1), the flux (4) is adjusted according to a loss (7) of the asynchronous machine (1). Therefore, an apparatus for determining the flux (4) of the asynchronous machine (1) is provided with a model (5) for calculating a loss (7) of the asynchronous machine (1) according to the flux of the asynchronous machine and with a selector device (8) for selecting a flux (7) according to the loss.