Transformer Core Structure for Leakage Inductance and Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional EE core transformers have high leakage inductance, making them unsuitable for high-frequency applications such as 160 to 300 kHz, and they also suffer from heat dissipation issues that can lead to increased temperature and reduced efficiency.
Innovation Solution
A transformer design with a core unit featuring a closed and open area structure, where the coils are wound to surround specific center and outer legs, and a heat dissipation member is integrated to manage temperature, allowing for precise adjustment of leakage inductance and efficient heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional EE core structure is used, then the transformer can be manufactured with simple structure, but the leakage inductance is high and unsuitable for high-frequency driving
Solution Approach 1:
The core is divided into multiple legs (first center leg, first outer legs, second center leg, second outer legs) with distinct functional zones. The closed area contains the first center leg and first outer legs for main magnetic flux, while the open area contains the second center leg and second outer legs for leakage flux control, enabling independent optimization of each segment's function
Solution Approach 2:
Different regions of the core are designed with different properties: the closed area provides a complete magnetic path for low reluctance, while the open area provides controlled magnetic reluctance for leakage inductance. The first coil surrounds both center legs in the closed area for main coupling, while the second coil surrounds only the first center leg for differential winding, creating local magnetic coupling characteristics
2Reliability
If the core structure is modified to reduce leakage inductance, then high-frequency performance improves, but the manufacturing complexity increases
Solution Approach 1:
The core structure serves multiple functions simultaneously: the closed area provides both magnetic flux path and structural support, the open area provides both leakage flux control and cooling channel, the first and second center legs both provide magnetic path and serve as winding supports, eliminating the need for separate components for each function
Solution Approach 2:
The design transitions from a conventional planar EE core to a three-dimensional structure with distinct closed and open areas, allowing magnetic flux paths to be controlled in multiple spatial dimensions. The first and second center legs are positioned at different heights and surrounded by different coil configurations, creating vertical and horizontal magnetic coupling paths
3Productivity
If high-frequency driving is implemented, then power density increases, but heat dissipation becomes more difficult and temperature increases
Solution Approach 1:
The core structure incorporates an open area that functions as a porous-like structure, providing channels for air circulation and heat dissipation. The open area between the first and second center legs allows thermal convection paths, enabling efficient heat removal from the winding regions without compromising magnetic performance
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 design achieves a leakage inductance of 15 to 20 μH, suitable for high-frequency driving, while maintaining thermal equilibrium and improving power supply unit efficiency by reducing temperature increases.
Implementation Method 1
A planar transformer, for example, an LLC resonant converter, may secure desired leakage inductance by increasing leakage flux through a shape design of a core
Implementation Method 2
a heat dissipation member is disposed to dissipate heat generated from a core unit and a coil unit, thereby minimizing an increase in temperature of the transformer, thus achieving thermal equilibrium in the transformer
Data Source
AI summary
The present invention relates to a transformer and a circuit board comprising same. One embodiment of the transformer according to the present invention comprises: a core part comprising a core lower portion and a core upper portion disposed on the core lower portion; and a coil part which comprises a first coil and a second coil and of which at least a portion is disposed in the core part, wherein the core lower portion has a closed region which overlaps the core upper portion in a first direction from the core lower portion toward the core upper portion, and an open region which extends from the closed region in a second direction perpendicular to the first direction and which is exposed to the outside of the closed area.