Welding Power Supply Topology Without a Separate Rectifier Stage
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Solution Overview
Problem
Conventional welding power supply topologies, such as full-bridge and half-bridge circuits, suffer from inefficiencies due to excess losses, idle semiconductor devices, and the need for separate rectifier and assist circuitry to handle reactive energy, which complicates heat management and increases size and cost.
Innovation Solution
A switched mode power supply-based welding power source that combines a rectifier stage with a commutation stage using semiconductor devices, allowing for the selection of switching elements to perform rectification and commutation functions, and includes a control circuit to manage energy transfer and heat dissipation, enabling the output of welding voltages with desired polarity without a separate rectifier stage and efficient reverse power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional full-bridge or half-bridge circuits are used, then welding power can be supplied, but excess losses occur and heat management becomes complicated
Solution Approach 1:
The patent combines the rectifier stage and commutation stage into a single integrated circuit using semiconductor devices. This merging eliminates the need for separate rectifier and assist circuitry, reducing total losses and simplifying heat management by consolidating thermal sources into fewer components that can be managed through unified heat sink designs.
Solution Approach 2:
The semiconductor devices in the patent perform multiple functions simultaneously - they serve as both rectifiers and commutation elements. This multi-functionality reduces the number of idle semiconductor devices and eliminates the need for separate assist circuitry, thereby reducing energy losses and simplifying the overall heat management system.
2Reliability
If separate rectifier and assist circuitry are used, then reactive energy can be handled, but device size and cost increase
Solution Approach 1:
The patent merges the rectifier and commutation functions into a single integrated circuit, eliminating the need for separate assist circuitry. This consolidation reduces the overall size and weight of the power supply while maintaining the ability to handle reactive energy through the unified semiconductor device architecture.
Solution Approach 2:
The semiconductor devices are designed to perform multiple functions - rectification and commutation - within a single component. This multi-functionality eliminates the need for additional separate circuitry, thereby reducing the power supply size and weight while maintaining full reactive energy handling capability.
3Ease of operation
If idle semiconductor devices are present, then circuit functionality is maintained, but efficiency decreases
Solution Approach 1:
The patent designs the semiconductor devices to perform multiple functions - serving as both rectifiers and commutation elements. This eliminates idle semiconductor devices that would otherwise be present in conventional designs, improving efficiency while maintaining full circuit functionality through the versatile multi-functional devices.
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 solution reduces heat losses, improves thermal management, and enables more compact and efficient welding power sources by utilizing semiconductor devices for both rectification and commutation, while efficiently handling reactive energy and enhancing arc stability and reducing audio emissions.
Implementation Method 1
a transformer having a primary winding, a first secondary winding, and a second secondary winding
Implementation Method 2
switching elements to control current flow from the first and second secondary windings to an output
Data Source
AI summary
An example welding-type power supply includes: a transformer having a primary winding and first and second secondary windings; an input circuit configured to provide an input voltage to the primary winding of the transformer; first, second, third, and fourth switching elements, and a control circuit configured to: control the first, second, third, and fourth switching elements to selectively output a positive or negative output voltage without a separate rectifier stage by selectively controlling ones of the first, second, third, and fourth switching elements based on a commanded output voltage polarity and an input voltage polarity to the transformer; and prior to changing from a first output voltage polarity to a second output voltage polarity, controlling the first, second, third, and fourth switching elements to reverse the power flow to return reactive energy to an input circuit via the transformer.