Inductor Current Estimation With Compensation for Converter Control

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Solution Overview

Problem

Existing power converters face challenges in accurately controlling inductor current due to measurement irregularities, such as delay and noise, which can lead to undesirable events like inductor saturation, requiring effective methods to estimate and compensate current signals for precise control.

Innovation Solution

A method and system that generate predicted sensed and instantaneous current signals based on power converter operating parameters, compensate these signals using modeling units and controllers to account for measurement irregularities, and adjust power converter parameters for accurate control, employing components like current sensors, modeling units, and proportional integral controllers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current sensing is performed using a current sensor, then current measurement is obtained, but measurement irregularities such as delay and noise occur

Engineering Contradiction:
Improvecurrent measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary compensation mechanism that processes the sensed current signal through multiple stages. A first compensation circuit compensates for sensor-specific irregularities (delay, noise) in the sensed current signal, then a second compensation circuit further compensates the instantaneous current signal based on the compensated sensed current signal. This multi-stage intermediary processing resolves the contradiction by filtering out measurement irregularities while preserving the essential current information needed for reliable control.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs feedback mechanisms where the compensated sensed current signal is used to generate compensation signals that are fed back into the instantaneous current signal processing. The controller uses the compensated sensed current signal to adjust and refine the instantaneous current signal, creating a closed-loop feedback system that continuously corrects for measurement irregularities, thereby improving both accuracy and reliability simultaneously.

Inventive Principle:
Principle #23Feedback

2Device complexity

If inductor current control is performed without compensation, then control simplicity is maintained, but inductor saturation may occur

Engineering Contradiction:
Improvecontrol system complexityVSAvoidinductor saturation prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by compensating the instantaneous current signal in advance before it is used for control decisions. The first and second compensation circuits process the current signals beforehand to predict and correct for potential measurement irregularities and control delays. This preliminary compensation ensures that when the controller makes decisions based on the compensated signal, the actual inductor current is already being properly managed, preventing saturation while maintaining relatively simple control logic.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple compensation stages are applied, then current signal accuracy is improved, but processing complexity increases

Engineering Contradiction:
Improvecurrent signal accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the compensation process into two distinct stages: a first compensation circuit that handles sensor-specific irregularities in the sensed current signal, and a second compensation circuit that further compensates the instantaneous current signal based on the compensated sensed current signal. This segmentation allows each stage to focus on specific compensation tasks, improving overall accuracy while keeping each individual processing stage relatively simple and manageable.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4485777A1Method and apparatus for estimating voltage regulator current
Publication Date: 2025.01.01 INFINEON TECH AUSTRIA AG
  • EP4485777A1 patent drawingFigure 1
  • EP4485777A1 patent drawingFigure 2
  • EP4485777A1 patent drawingFigure 3

AI summary

A method and apparatus for estimating inductor current is provided. According to some embodiments, a method comprises generating a predicted sensed current signal for sensed current in an inductor of a power converter based on a power converter operating parameter, receiving a sensed current signal generated based on current in the inductor, compensating the predicted sensed current signal based on the sensed current signal to generate a compensated sensed current signal, generating a predicted instantaneous current signal for instantaneous current in the inductor based on the power converter operating parameter, compensating the predicted instantaneous current signal based on the compensated sensed current signal to generate an estimated instantaneous current signal, and controlling the power converter based on the estimated instantaneous current signal.