Adaptive Q-Tuning in LLC Resonant Converters Under Heavy Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LLC resonant converters face issues with insufficient voltage gain due to heavy loads and frequent dynamic responses, leading to power loss and unstable output voltage.
Innovation Solution
A resonant converter that adaptively tunes its quality factor based on load conditions by detecting rectifying current and adjusting the resonant tank configuration, including inductance and capacitance, to maintain stable output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switching frequency is decreased to obtain more voltage gain under heavy load, then the output voltage stability is improved, but the conversion efficiency deteriorates due to increased power loss
Solution Approach 1:
The patent changes the quality factor parameter of the resonant tank adaptively based on load conditions. When the load is heavy, the quality factor is reduced to increase voltage gain without excessively lowering the switching frequency, thereby maintaining both output voltage stability and conversion efficiency.
2Ease of manufacture
If the quality factor is fixed in conventional LLC resonant converters, then the circuit design is simplified, but the adaptability to different load conditions deteriorates
Solution Approach 1:
The patent makes the quality factor dynamic by introducing a control circuit that adjusts it according to the actual load conditions. This allows the converter to adapt to different load scenarios while maintaining a relatively simple circuit structure through automated control.
Solution Approach 2:
The patent implements a feedback mechanism where the controller monitors the load conditions and adjusts the quality factor accordingly. This closed-loop control enables the system to maintain optimal performance across varying load conditions without complex manual intervention.
3Ease of manufacture
If the resonant tank components are fixed, then the manufacturing cost is reduced, but the voltage gain sufficiency under heavy load deteriorates
Solution Approach 1:
Instead of changing the physical components of the resonant tank, the patent changes the effective quality factor parameter through control circuitry. This approach maintains manufacturing simplicity while achieving the necessary voltage gain adjustment for heavy load 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
The converter effectively adjusts its output gain to prevent insufficient voltage by dynamically changing its quality factor in response to load changes, ensuring stable operation and efficient power conversion.
Implementation Method 1
The resonant tank is a resonant circuit, having a set of inductors and a set of capacitors jointly oscillating at a specific frequency (referred to as the resonant frequency)
Implementation Method 2
The transformer at least includes a primary winding, and a first secondary winding; wherein the primary winding is coupled to the magnetizing inductor
Data Source
AI summary
Provided is a resonant converter capable of adaptively tuning a quality factor based on load. The resonant converter includes a resonant tank having an inductor part whose inductance is tunable according to a first control potential, a magnetizing inductor, and a capacitor part whose capacitance is tunable according to a second control potential. The resonant converter detects the rectifying current of its output stage for responding to the load state of the resonant converter. The resonant converter outputs the first and second control potentials in response to the load state, tuning the equivalent inductance of the inductor part, the equivalent capacitance of the capacitor part, or both, thereby changing the quality factor of the resonant converter.