Hybrid Resonant Rectifier Circuit for Odd Voltage Conversion
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Solution Overview
Problem
Non-isolated LLC circuits face challenges in achieving an odd voltage conversion ratio while reducing transformer loss and volume.
Innovation Solution
A non-isolated hybrid resonance conversion circuit is introduced, featuring a full-wave rectifier circuit with parallel rectifying branches, a switching circuit, and resonant units, allowing for odd voltage conversion ratios by utilizing primary switches to directly supply current to the load and employing idle windings for excitation, thereby reducing transformer turns and losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a non-isolated LLC circuit is used to achieve high voltage conversion ratio and ZVS, then the voltage conversion capability is improved, but the efficiency cannot be very high and transformer loss is significant
Solution Approach 1:
The patent segments the transformer windings into multiple independent windings (first winding, second winding, third winding) with different functions. The first and second windings form a full-wave rectifier circuit for power delivery, while the third winding provides excitation current. This segmentation allows each winding to be optimized for its specific function, reducing overall transformer loss while maintaining high voltage conversion ratio.
Solution Approach 2:
The patent makes the transformer windings multi-functional. The first and second windings serve dual purposes: they provide power delivery to the load while also contributing to excitation current generation. The third winding provides excitation current and enables the circuit to achieve odd voltage conversion ratios. This multi-functionality reduces the need for separate excitation windings, minimizing transformer loss.
2Power
If all energy conversion is through the transformer in LLC circuit, then voltage conversion is achieved, but the efficiency is reduced due to transformer losses
Solution Approach 1:
The patent introduces a resonant unit (comprising resonant inductor and resonant capacitor) as an intermediary between the switching circuit and the transformer. This resonant unit enables soft switching operation, reducing switching losses and improving overall conversion efficiency. The resonant unit mediates the energy transfer process, allowing the circuit to operate at higher efficiency while maintaining the required voltage conversion capability.
3Loss of energy
If only one winding works in each half period in full-wave rectifier circuit, then rectification is achieved, but another winding is idle and transformer volume cannot be reduced
Solution Approach 1:
The patent ensures continuous useful action by having multiple windings operate simultaneously in different configurations. During each half period, the first and second windings work together in the full-wave rectifier circuit, while the third winding provides continuous excitation current. This continuous utilization of all windings eliminates idle time, maximizes energy transfer efficiency, and allows for compact transformer design with reduced volume.
4Reliability
If primary switches only produce excitation current that returns to input, then ZVS is achieved, but all load current must be supplied by secondary circuit causing large current stresses
Solution Approach 1:
The patent merges the excitation current function and load current delivery function into the same primary circuit path. The first and second windings are configured so that the excitation current generated by primary switches flows through the full-wave rectifier circuit to directly supply the load. This merging eliminates the need for separate secondary current paths, reducing current stresses on secondary components while maintaining ZVS operation through proper resonant control.
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 circuit achieves high efficiency and odd voltage conversion ratios with reduced transformer size and loss by utilizing primary excitation current directly to the load and optimizing transformer design.
Implementation Method 1
a first resonant unit coupled between the first connection node and the first midpoint... the first winding and the second winding are coupled to each other... a third winding connected with the first resonant unit in series and electrically coupled between the first connection node and the first midpoint
Implementation Method 2
non-isolated hybrid resonance conversion circuit... first resonant unit... resonant frequency fr=1/(2π×√{square root over (Lr×C1)})
Data Source
AI summary
The disclosure provides a non-isolated hybrid resonance circuit for powering a load by converted voltage, including: a full-wave rectifier circuit connected in parallel to the load, and having a first and second rectifying branch connected in parallel, each rectifying branch having a rectifying switch and a winding connected in series; a first switching circuit connected between the first end of the power supply and the first end of the load, and including a first and second switch connected in series; and a first resonant unit electrically coupled between the first connection node formed by the first and second switch connected in series and the midpoint of the first rectifying branch, wherein the windings of the first and second rectifying branches are coupled to each other. The conversion circuit provided by the disclosure can realize an odd voltage conversion ratio, and can reduce loss and volume of the transformer.