Multi-Output LLC DC/DC Converter Cross-Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-output DC/DC converters face limitations in power conversion efficiency and increased manufacturing costs due to the use of a buck chopper circuit for cross-regulation, which also complicates the design with additional components.
Innovation Solution
A multi-output DC/DC converter that controls power conversion switching in synchronization with the frequency of one output voltage using an LLC resonant converter, eliminating the need for a buck chopper circuit by employing a control circuit with frequency and duty control units to manage switching signals for multiple output voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a buck chopper circuit is used for cross-regulation in a multi-output DC/DC converter, then the cross-regulation between multiple output voltages is maintained, but the power conversion efficiency is reduced due to switching and conduction losses
Solution Approach 1:
The invention extracts and removes the buck chopper circuit from the system. By using a resonant converter topology with primary and secondary sides, the cross-regulation function is achieved through the transformer coupling and resonant control rather than through a separate buck chopper circuit, thereby eliminating the switching and conduction losses associated with the buck chopper while maintaining cross-regulation capability.
Solution Approach 2:
The invention introduces a resonant converter as an intermediary between the input voltage and multiple output voltages. The resonant converter with its transformer and resonant tanks acts as a mediator that provides galvanic isolation and enables cross-regulation through magnetic coupling, replacing the direct buck chopper approach and improving power conversion efficiency.
2Reliability
If a buck chopper circuit is added for cross-regulation, then the cross-regulation is maintained, but the number of components increases and manufacturing cost rises
Solution Approach 1:
The invention merges the cross-regulation function into the main power conversion path by using a resonant converter topology. The transformer and resonant tanks are integrated into the primary and secondary circuits, combining voltage conversion and cross-regulation functions into a unified structure, thereby reducing the total number of components compared to a separate buck chopper circuit approach.
Solution Approach 2:
The resonant converter is designed to perform multiple functions simultaneously: voltage conversion, galvanic isolation, and cross-regulation between multiple outputs. This multi-functionality eliminates the need for dedicated buck chopper circuits, reducing component count and manufacturing complexity while maintaining all required functions.
3Device complexity
If a single transformer is used for multiple output voltages, then the device complexity is reduced, but the ability to independently control each output voltage is lost
Solution Approach 1:
The invention segments the secondary side of the transformer into multiple independent resonant tanks, each with its own rectifier and control circuitry. This segmentation allows each output voltage to be independently regulated through its dedicated resonant tank and control loop, while the primary side uses a single transformer for voltage conversion, achieving both simplicity and independent control capability.
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
This approach enhances power conversion efficiency by eliminating switching and conduction losses associated with the buck chopper circuit, reduces manufacturing costs by minimizing components, and allows for independent control of each output voltage, thereby maintaining cross-regulation without the need for additional circuitry.
Implementation Method 1
A multi-output direct-current (DC)/DC converter capable of controlling power-conversion switching in synchronization with a frequency of one output voltage among multiple output voltages without using a buck chopper circuit, which is constructed at an output terminal, in an LLC resonance DC/DC converter
Data Source
AI summary
Disclosed is a multi-output DC/DC converter controlling power-conversion switching in synchronization with a frequency of one output voltage among multiple output voltages in an LLC resonant DC/DC converter. The multi-output DC/DC converter includes a power conversion circuit performing alternate switching on an input DC voltage to output multiple DC voltages including a first DC voltage and a second DC voltage each having a preset voltage level, and a control circuit controlling the alternate switching of the power conversion circuit in synchronization with a preset resonant frequency.