High-frequency transformers using solid wire for welding-type power supplies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency transformers used in welding power supplies face challenges due to the high cost and difficulty in terminating and routing Litz wire, which is expensive and difficult to work with.
Innovation Solution
The use of solid wire with U-shaped ferrite cores and obround cross-section bobbins, along with a tertiary winding and parallel primary windings, reduces production costs and simplifies termination and routing, while maintaining thermal performance and magnetic coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Litz wire is used in high-frequency welding transformers, then the transformer can operate at high frequency with good magnetic field averaging, but the cost increases significantly and termination and routing become difficult
Solution Approach 1:
The patent divides the primary winding into multiple separate solid wire windings (first primary winding, second primary winding, etc.) instead of using a single Litz wire. Each solid wire winding is wound independently around the bobbin, allowing for simpler manufacturing and termination while still achieving the required high-frequency operation through proper spacing and insulation between the segmented windings.
2Reliability
If Litz wire is used in high-frequency welding transformers, then magnetic field averaging is achieved, but the flexibility and ease of routing are reduced
Solution Approach 1:
By segmenting the primary winding into multiple independent solid wire windings, each winding can be individually routed and connected. This segmentation provides routing flexibility that is not available with solid Litz wire, while the multiple windings collectively achieve the magnetic field averaging effect through their spatial distribution around the core.
Solution Approach 2:
The patent distributes multiple primary windings in different spatial positions around the bobbin (first primary winding on one side, second primary winding on another side, etc.). This spatial distribution in multiple dimensions achieves magnetic field averaging without requiring the complex internal structure of Litz wire, thereby improving routing flexibility.
3Ease of manufacture
If solid wire is used instead of Litz wire, then cost is reduced and termination is simplified, but maintaining high-frequency operation and thermal performance becomes challenging
Solution Approach 1:
The primary winding is divided into multiple solid wire windings that are spatially distributed around the bobbin. This segmentation allows each solid wire to be individually managed for thermal dissipation while collectively achieving the required electrical performance. The multiple windings can be connected in parallel to reduce overall resistance and improve current handling capability.
Solution Approach 2:
The patent applies different insulation and spacing characteristics to different regions of the solid wire windings. Proper insulation materials and spacing are used between adjacent windings to prevent breakdown at high frequencies, while maintaining optimal thermal pathways. This local optimization ensures both high-frequency reliability and thermal 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 solution results in a transformer that is lower in cost and easier to assemble, with improved thermal management and reduced need for additional components, achieving efficient high-frequency operation.
Implementation Method 1
High-frequency transformers operating at high voltages and high currents are used in conventional welding power supplies. The output stage of a welding power supply, for example, may include an electromagnetic transformer to transform a higher bus voltage of a welding power supply into a high current welding output.
Implementation Method 2
The use of solid wire with U-shaped ferrite cores and obround cross-section bobbins
Data Source
AI summary
High-frequency transformers using solid wire for welding-type power supplies are disclosed. An example welding-type power supply transformer includes: a first coil assembly comprising a first plurality of turns of a first solid wire wrapped around a first bobbin to form a first single-layer primary winding, and a second plurality of turns of a second conductor over the first plurality of turns to form a first single-layer secondary winding; a second coil assembly comprising a third plurality of turns of a second solid wire wrapped around a second bobbin to form a second single-layer primary winding, and a fourth plurality of turns of the second conductor over the third plurality of turns to form a second single-layer secondary winding, the first single-layer primary winding being in parallel with the second single-layer primary winding, wherein the second conductor comprises at least one of an obround cross-section, a rectangular cross-section, or a rectangular cross-section having radiused corners, the second plurality of turns have a transverse cross-section of the second conductor that is constant along at least the portion of the second conductor comprising the second plurality of turns, and the fourth plurality of turns have a transverse cross-section of the second conductor that is constant along at least the portion of the second conductor comprising the fourth plurality of turns; and first and second cores disposed at least partially within the first and second bobbins.