LLC Resonant Converter Topology for Wide Voltage Gain
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Solution Overview
Problem
Conventional power converters, particularly point of load (POL) converters, face challenges in achieving a wide gain range, high efficiency, and reduced component size and cost, while introducing noise and thermal issues due to mismatched power sources and needs.
Innovation Solution
The LLC resonant converter design incorporates a voltage divider and multiple half-bridges coupled with resonant circuit modules, utilizing transformers and switches to control power flow and achieve a wide voltage gain range, with interleaved operation modes to manage output current ripple and voltage regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional power converters are used to achieve wide gain range, then voltage conversion flexibility is improved, but component size and cost increase
Solution Approach 1:
The converter is divided into multiple half-bridge modules (first half-bridge, second half-bridge, high voltage half-bridge) that can operate independently or in combination. This segmentation allows the system to achieve wide voltage gain range by selectively activating different modules, thereby avoiding the need for a single large-scale converter that would increase component size.
Solution Approach 2:
The converter employs dynamic switching control where the operational state of each half-bridge module changes based on the required voltage gain. The controller dynamically adjusts which modules are active, enabling the system to adapt to different voltage conversion requirements without requiring all components to be permanently sized for maximum gain, thus reducing overall component size.
2Adaptability or versatility
If multiple half-bridges and resonant circuits are used to achieve wide gain range, then voltage conversion flexibility is improved, but device complexity increases
Solution Approach 1:
Each half-bridge module is designed with universal functionality to perform multiple roles depending on operational mode. The same basic module structure (switches, resonant circuit) can operate in different configurations to achieve various voltage gains, reducing the need for specialized components for each function and simplifying the overall design despite the multi-module architecture.
Solution Approach 2:
The controller acts as an intermediary that manages the complexity of coordinating multiple half-bridge modules. By centralizing the control logic, the system can manage the complex interactions between modules without requiring complex interconnections or coordination circuits, thereby reducing overall device complexity while maintaining wide gain range capability.
3Loss of energy
If resonant converters are used for power conversion, then efficiency is improved, but noise and thermal load are introduced
Solution Approach 1:
The resonant converter operates using periodic switching actions at resonant frequencies, which enables efficient energy transfer while distributing thermal load over time. The periodic nature of the operation allows for thermal management through cyclic duty cycles, and the resonant operation minimizes switching losses that would otherwise generate noise and heat, thereby maintaining efficiency while reducing harmful effects.
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 LLC resonant converter achieves a voltage gain range of six or greater, maintaining high power density and efficiency, reducing costs and noise, and supporting a wide range of input and output voltages, suitable for applications like electric vehicle chargers.
Implementation Method 1
a resonant converter is a type of electric power converter that contains a network of inductors and capacitors called a resonant tank. The values of the inductors and capacitors are selected so that the network resonates at a specific frequency.
Implementation Method 2
A transformer is conventionally utilized to increase or decrease the alternating voltages in electric power applications.
Data Source
AI summary
According to an aspect of this disclosure, a circuit includes a voltage source and an output load, first and second resonant modules disposed between the voltage source and the output load, and first and second transformers. The circuit is further arranged such that the first transformer is disposed between the first resonant module and the output load, and the second transformer is disposed between the second resonant module and the output load. The circuit also includes a plurality of half-bridges coupled between the first and second resonant modules and the voltage source. The circuit further includes a voltage divider disposed between the voltage source and the plurality of half-bridges.