Planar Resonant Converter Transformer Layout for Lower AC Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional resonant converters are bulky due to inductive components like transformers with windings and iron cores, leading to high AC impedance and efficiency issues, and magnetic flux saturation.
Innovation Solution
A resonant converter design featuring a planar transformer with interleaving windings on a circuit board, utilizing an iron core and vias to reduce size and AC impedance through magnetic flux cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional inductive components (transformers with windings and iron cores) are used in resonant converters, then the converter can function properly, but the size becomes bulky and power density decreases
Solution Approach 1:
The patent transitions from traditional three-dimensional wound transformers to a planar two-dimensional transformer structure. The transformer windings are laid out on a circuit board plane rather than being wound in three-dimensional space around a core, dramatically reducing the vertical height and overall volume of the inductive components while maintaining the necessary magnetic coupling.
Solution Approach 2:
The patent divides the transformer into multiple separate planar winding layers on different circuit board layers, with each layer serving a specific function. The primary and secondary windings are segmented into distinct conductive trace patterns on different planes, connected through vias, allowing for compact integration while maintaining electrical isolation and magnetic coupling.
2Loss of energy
If single-core wire windings are used in transformers, then the transformer can be constructed, but AC impedance becomes large and efficiency decreases
Solution Approach 1:
The patent uses planar conductive traces on circuit board layers instead of three-dimensional wire windings. This two-dimensional approach reduces the path length and parasitic inductance of the windings, thereby reducing AC impedance and improving efficiency at high switching frequencies.
Solution Approach 2:
The patent integrates the transformer windings directly into the circuit board structure by using copper traces and vias as the winding elements, merging the functions of the circuit board and transformer windings into a single integrated structure. This eliminates separate wire windings and reduces overall complexity.
3Reliability
If windings are wound in the same direction, then the transformer can be constructed, but magnetic flux superposition occurs causing saturation and short-circuiting
Solution Approach 1:
The patent employs asymmetric winding arrangements where adjacent winding segments are oriented in opposite directions. The conductive traces are routed to create alternating current paths that generate opposing magnetic fluxes, preventing flux superposition and core saturation while maintaining reliable transformer operation.
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 planar transformer design reduces the size of the resonant converter, minimizes AC impedance, and enhances efficiency by canceling magnetic flux, improving power density and performance.
Implementation Method 1
the wirings interleavingly extend to the first sub-layer board and the second sub-layer board through the plurality of vias, and the wirings on the same layer are arranged in parallel
Data Source
AI summary
A resonant converter includes a circuit board, a primary-side circuit, a secondary-side circuit and a planar transformer. The planar transformer includes a first through hole, an iron core, a plurality of vias, and a plurality of wirings. The planar transformer is electrically connected to the primary-side circuit and the secondary-side circuit. The first through hole penetrates through the circuit board, and the iron core includes a first core column penetrating through the first through hole. The vias are electrically connected to a first sub-layer board and a second sub-layer board of the circuit board, and the wirings are formed around the first through hole to be used as a winding of the planar transformer. The wirings interleavingly extend to the first sub-layer board and the second sub-layer board through the vias, and the wirings on the same layer are arranged in parallel.