Adaptive Half-Bridge Transition Sensing for Leakage Inductance Drift

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Solution Overview

Problem

Existing asymmetrical half bridge converter systems face challenges in accurately determining the transition time due to variations in leakage inductance tolerance, leading to inefficiencies and potential noise sensitivity.

Innovation Solution

An adaptive transition controller is introduced, comprising derivative, peak detector, integrator, and comparator circuits, which filter and process signals to determine the end of resonance by extending the derivative signal, thereby enabling precise control of the transition time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional transition time measurement is used in asymmetrical half bridge converters, then the system structure remains simple, but measurement precision deteriorates due to leakage inductance tolerance variations

Engineering Contradiction:
Improvetransition time measurement precisionVSAvoidcontroller circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller is divided into multiple functional modules: derivative circuit for signal differentiation, peak detector for extracting maximum values, integrator for accumulating signals over time, and comparator for threshold comparison. Each module performs a specific function in the transition time measurement process, allowing the system to achieve high precision without requiring a completely complex redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The derivative circuit processes the resonant current signal in advance to generate a derivative signal that highlights the transition point. The peak detector then identifies the maximum value of this derivative signal before the actual transition time determination occurs, preparing the data for more accurate measurement by the integrator and comparator.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If adaptive transition control is implemented, then transition time measurement precision improves, but noise sensitivity increases due to signal processing operations

Engineering Contradiction:
Improvetransition time measurement precisionVSAvoidnoise sensitivity
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The controller uses feedback from the resonant current signal and its derivative to continuously monitor and determine transition time. The integrator accumulates the derivative signal over time, and the comparator uses this integrated value to detect the transition point, creating a feedback mechanism that improves precision while the natural filtering properties of integration reduce noise sensitivity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The derivative signal serves as an intermediary between the raw resonant current signal and the final transition time determination. By introducing this intermediate processing step, the system can identify transition points more accurately while the subsequent integration process naturally filters out high-frequency noise, resolving the contradiction between precision and noise sensitivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If leakage inductance tolerance variations are not compensated, then device complexity remains low, but productivity decreases due to inefficiencies in converter operation

Engineering Contradiction:
Improveconverter operation efficiencyVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The controller automatically determines transition time by processing the resonant current signal through derivative, peak detection, integration, and comparison operations. The system self-adjusts to leakage inductance variations without requiring external calibration or manual intervention, improving converter efficiency while keeping the control mechanism integrated and relatively simple.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller dynamically changes its measurement approach by using derivative signals and integrated values instead of direct current measurement. This parameter transformation allows the system to compensate for leakage inductance tolerance variations, improving operational efficiency without requiring complex hardware modifications.

Inventive Principle:
Principle #35Parameter changes

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

The adaptive transition controller effectively addresses the inefficiencies and noise sensitivity issues by providing a precise and adaptive mechanism for determining the transition time, enhancing the overall performance of the asymmetrical half bridge converter system.

Implementation Method 1

a derivative circuit configured to receive a first signal indicative of a resonant current through an inductor in the resonant converter system and produce a derivative signal indicative of a derivative of the first signal

Methodology Applied
Scientific EffectDifferentiation:

Implementation Method 2

a peak detector circuit configured to produce a peak signal indicative of a peak value of the derivative signal over a time period

Methodology Applied
Scientific EffectPeak detection:

Implementation Method 3

an integrator circuit configured to integrate the peak signal to produce an extension signal

Methodology Applied
Scientific EffectIntegration:

Implementation Method 4

a comparator circuit configured to produce an end transition signal when the extension signal exceeds a second signal indicative of the magnetizing current in a magnetizing inductance of a transformer in the resonant converter system

Methodology Applied
Scientific EffectComparison:

Implementation Method 5

an extension filter connected to the derivative circuit, wherein the extension filter is configured to filter the first signal

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Data Source

PatentEP4568094A1Adaptive transition time measurement in an asymmetrical half bridge
Publication Date: 2025.06.11 NXP USA INC
  • EP4568094A1 patent drawingFigure 1A~1B
  • EP4568094A1 patent drawingFigure 2A~2B
  • EP4568094A1 patent drawingFigure 3~4

AI summary

An adaptive transition controller for a resonant converter system, including: a derivative circuit configured to receive a first signal indicative of a resonant current through an inductor in the resonant converter system and produce a derivative signal indicative of a derivative of the first signal; a peak detector circuit configured to produce a peak signal indicative of a peak value of the derivative signal over a time period; an integrator circuit configured to integrate the peak signal to produce an extension signal; and a comparator circuit configured to produce an end transition signal when the extension signal exceeds a second signal indicative of the magnetizing current in a magnetizing inductance of a transformer in the resonant converter system.