Variable Resonant Tank LLC Converter for Wider Output Range
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Solution Overview
Problem
Conventional LLC resonant converters have fixed resonant tank parameters, limiting their ability to adjust output voltage and current ranges, making it difficult to meet varying operational demands without compromising efficiency and power density.
Innovation Solution
A variable resonant tank design that dynamically adjusts resonant inductance and capacitance using switches and external controllers to modify the inductance ratio and quality factor, allowing for real-time adaptation of output voltage and current ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed resonant tank parameters are used, then the converter structure is simple, but the output voltage and current ranges are limited
Solution Approach 1:
The patent applies dynamics by making the resonant tank parameters adjustable rather than fixed. Switches are introduced to dynamically reconfigure the resonant inductor and capacitor connections, allowing the resonant frequency and impedance to be adapted in real-time to meet varying output requirements while maintaining converter operation
Solution Approach 2:
The resonant tank is segmented into multiple adjustable components - specifically, the resonant inductor is divided into multiple inductors that can be connected in series or parallel through switches, and the resonant capacitor is divided into multiple capacitors with similar switching configurations. This segmentation enables flexible parameter adjustment to expand output ranges
2Volume of moving object
If switching frequency is increased to reduce magnetic element size, then miniaturization is achieved, but switching loss increases
Solution Approach 1:
The patent changes the resonant tank parameters (inductance and capacitance values) dynamically to optimize the resonant frequency at different operating conditions. By adjusting the effective L and C values through switch configurations, the converter can maintain efficient operation at higher switching frequencies while minimizing switching losses through improved soft-switching performance
3Adaptability or versatility
If resonant tank parameters are fixed, then the converter design is straightforward, but it cannot meet varying operational demands
Solution Approach 1:
The patent incorporates feedback control mechanisms where the controller monitors the output voltage and current requirements and adjusts the switch configurations in the resonant tank accordingly. This feedback loop enables the converter to automatically adapt to varying operational demands by reconfiguring the resonant parameters to match the required output conditions
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
Enables wider output voltage and current ranges while maintaining high efficiency and power density, overcoming the limitations of fixed resonant tank parameters in conventional LLC resonant converters.
Implementation Method 1
an inductor and a capacitor can be connected in series or in parallel to form a resonant circuit, when the power supply is a DC power supply, the current in the resonant circuit changes according to a sinusoidal law
Implementation Method 2
This in turn feeds a transformer that provides voltage scaling and primary-secondary isolation
Data Source
AI summary
An LLC resonant converter with variable resonant tank includes a switching circuit for converting a DC voltage into switching signal, a variable resonant tank coupled to the switching circuit for receiving the switching signal to provide a primary current, a transformer circuit having a primary and a secondary side winding, and a rectifying/filtering circuit to rectifying and filtering a secondary current. The variable resonant tank is coupled between the switching circuit and the transformer circuit, which includes a variable resonant inductor, a magnetizing inductance and a resonant capacitor coupled in series for dynamically adjusting the gain curve of the LLC resonant converter according to the demand of the output current.