Resonant Hybrid Flyback Control for LED Flicker and Current Peaks

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Solution Overview

Problem

Current resonant hybrid flyback converters for LED-based loads fail to effectively improve flicker during load transitions and reduce peak-to-peak magnetizing current, leading to inefficiencies and reliability issues.

Innovation Solution

A resonant hybrid flyback converter system with a half-bridge circuit and a processing unit that controls the on-time of high-side and low-side switches based on peak detection of the half-bridge current, allowing for adjustments in on-time to optimize LED voltage and current, thereby improving efficiency and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional resonant hybrid flyback converters are used, then the basic LED supply function is achieved, but flicker occurs during load transitions and peak-to-peak magnetizing current is excessive

Engineering Contradiction:
Improveflicker during load transitionsVSAvoidpeak-to-peak magnetizing current
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic control of the half-bridge circuit by adjusting the on-time of switches based on real-time detection of magnetizing current peaks and LED voltage levels. The control unit dynamically modifies switching parameters during operation to maintain optimal operating conditions, thereby reducing flicker and controlling magnetizing current effectively

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the control unit continuously monitors LED voltage and half-bridge current, then adjusts switching parameters accordingly. This closed-loop control enables the system to respond to load transitions and maintain stable operation, eliminating flicker while managing magnetizing current peaks

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If the on-time of switches is extended to improve LED voltage regulation, then voltage stability improves, but the operation range becomes limited and efficiency decreases

Engineering Contradiction:
ImproveLED voltage regulationVSAvoidoperation range
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The control unit dynamically adjusts switch on-times based on real-time detection of LED voltage and current conditions. By varying the on-time parameter adaptively rather than using fixed values, the system maintains stable LED voltage regulation across a wide range of operating conditions and load transitions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters (switch on-time, frequency) dynamically based on detected conditions. The control unit modifies these parameters in response to LED voltage levels and load changes, enabling both stable regulation and wide operation range without sacrificing efficiency

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If magnetic resonant tank design is constrained by fixed parameters, then manufacturing is simplified, but the converter cannot achieve high efficiency across varying load conditions

Engineering Contradiction:
Improvemagnetic resonant tank designVSAvoidconverter efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

Rather than requiring complex fixed-parameter magnetic resonant tank designs, the patent uses a control unit that dynamically adjusts switching parameters. This approach maintains simple, manufacturable magnetic components while achieving high efficiency across varying loads through real-time parameter optimization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit automatically detects operating conditions and self-adjusts switching parameters to optimize efficiency. This self-regulating capability eliminates the need for complex pre-designed magnetic resonant tanks with fixed parameters, simplifying manufacturing while maintaining high efficiency across different operating conditions

Inventive Principle:
Principle #25Self-service

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 system ensures high efficiency and reliability by minimizing flicker during load transitions and reducing peak-to-peak magnetizing current, enabling a wider operation range and more flexible design of the magnetic resonant tank.

Implementation Method 1

a transformer with a primary side and a secondary side

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the processing unit is configured to sense a LED voltage with respect to the LED-based load and/or a half-bridge current with respect to the primary side

Methodology Applied
Scientific EffectElectrical measurement: Ohmmeter

Data Source

PatentEP4387395A1Resonant hybrid flyback converter for a led-based load
Publication Date: 2024.06.19 TRIDONIC GMBH & CO KG
  • EP4387395A1 patent drawingFigure 1
  • EP4387395A1 patent drawingFigure 2
  • EP4387395A1 patent drawingFigure 3

AI summary

A resonant hybrid flyback converter (10) for a LED-based load (13c) is provided. Said resonant hybrid flyback converter (10) comprises a half-bridge (11) comprising a high-side switch (11a) and a low-side switch (11b), a flyback resonant tank (12) comprising a transformer with a primary side (15a) and a secondary side (15b), and a processing unit (14). In this context, the half-bridge (11) is configured to supply said primary side (15a), wherein the secondary side (15b) is configured to supply the LED-based load (13c). Additionally, the processing unit (14) is configured to sense a LED voltage with respect to the LED-based load (13c) and/or a half-bridge current with respect to the primary side (15a). In further addition to this, the processing unit (14) is configured to control an on-time of the low-side switch (11b) on the basis of the LED voltage and/or an on-time of the high-side switch (11a) on the basis of a peak detection with respect to the half-bridge current.