Dual Output LLC Converter Phase Transition Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional control methods for dual independent output LLC converters are computationally intensive and often introduce critical conditions that disrupt operation, necessitating a simpler yet stable control solution.
Innovation Solution
A controller method that determines resonant capacitance voltage thresholds for each output and switches phases based on tank current thresholds, delaying transitions to maintain stability and prevent critical conditions, using a power converter with first and second switches and a control stage that manages these transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multidimensional control is used to control dual independent output LLC converters, then the converter can output two independent voltages, but the computational complexity required from control devices increases
Solution Approach 1:
The control method segments the complex multidimensional control into simpler sequential phase transitions (first phase, second phase, third phase, fourth phase). Each phase has specific switch configurations and control objectives, breaking down the computationally intensive simultaneous control of two independent outputs into manageable temporal stages with reduced computational requirements
Solution Approach 2:
The control implementation includes preliminary determination of resonant capacitance voltage thresholds based on output voltages before executing phase transitions. Minimum time periods are predetermined and enforced during phase transitions to prevent critical conditions, performing necessary control actions in advance to simplify real-time decision-making
2Device complexity
If Bang-Bang charge control is used to simplify control of dual-output LLC converters, then control complexity is reduced, but critical conditions are introduced that can disrupt operation
Solution Approach 1:
The control method applies preliminary anti-action by determining resonant capacitance voltage thresholds based on output voltages before phase transitions occur. Minimum time periods are enforced during transitions to prevent critical conditions from developing, counteracting potential instability before it can disrupt operation
Solution Approach 2:
The control implementation uses feedback by continuously monitoring resonant capacitance voltage and comparing it against dynamically determined thresholds that account for output voltages. This feedback mechanism adjusts phase transition timing to maintain operational stability while avoiding the critical conditions that plague simpler control methods
Data Source
AI summary
A method and apparatus for controlling a power converter are provided. In the method and apparatus, switching from a first phase to a second phase is delayed until it is determined that both a tank current signal of the converter goes below a tank current threshold and the converter has been in the first phase for more than a first minimum time period. Then the converter determines if a resonant capacitor voltage has fallen below a first resonant capacitance voltage threshold and if a tank current signal goes above a tank current threshold. The converter switches from the first phase to the second phase in response to determining at least one of: the resonant capacitor voltage has fallen below the first resonant capacitance voltage threshold and the tank current signal goes above the tank current threshold. The converter is additionally operated in third and fourth states.