Welding Power Supply With Auxiliary Windings for Extended Volt-Amp Range
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Solution Overview
Problem
Welding power supplies, particularly switched mode power supplies, face inefficiencies due to their limited ability to deliver a range of voltage and current, which is not effectively covered by existing control systems, especially in applications using cellulosic electrodes that require high current and varying voltage levels.
Innovation Solution
The implementation of a DC-DC power converter with a transformer stage and auxiliary secondary windings, along with active switches and PWM control, allows for extended voltage characteristics by modulating the leading and lagging edges of PWM signals based on current thresholds, enabling the power supply to cover a broader range of voltage and current outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a standard transformer ratio is used in welding power supply, then power conversion is effective at high current, but voltage output is limited and cannot cover high voltage at low current requirements
Solution Approach 1:
The patent divides the transformer secondary side into multiple independent winding sets (first set and second set of secondary windings) with different turns ratios. This segmentation allows each winding set to serve specific voltage-current ranges, enabling the power supply to cover both high voltage at low current and high current at low voltage without requiring a single complex transformer design.
Solution Approach 2:
The patent adds an additional dimension to the transformer structure by introducing auxiliary secondary windings connected through active switches. This creates a multi-dimensional voltage output capability where the system can selectively activate different winding combinations to achieve extended voltage characteristics beyond the standard transformer ratio limitations.
2Reliability
If control system limits output voltage at high current, then current is protected, but the power supply cannot deliver both maximum voltage and maximum current when needed
Solution Approach 1:
The patent implements dynamic switching between different secondary winding sets based on real-time current conditions. The control system activates the first set of secondary windings for high current operations and switches to the second set for lower current, higher voltage requirements. This dynamic reconfiguration allows the power supply to adapt its voltage-current characteristics to match the actual welding process needs while maintaining protective current limiting.
3Device complexity
If a single power supply design is used, then device simplicity is maintained, but it cannot effectively cover the entire rectangular plane of voltage-current characteristics
Solution Approach 1:
The patent creates a universal power supply design where a single transformer unit with multiple secondary winding sets can perform multiple functions. By selectively activating different winding combinations through controlled switches, the same physical transformer can deliver both high voltage at low current and high current at low voltage, making the device universally applicable to various welding processes including cellulosic electrode welding without requiring multiple specialized power supplies.
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 enhances the effectiveness of welding power supplies by providing a more flexible and efficient output voltage-current characteristic, improving performance in applications with varying current and voltage demands, such as those using cellulosic electrodes.
Implementation Method 1
a transformer stage. The transformer stage may include at least one power transformer to receive the primary current from the DC-AC power converter on a primary side of the transformer stage and to output a first voltage through a first set of secondary windings
Implementation Method 2
The first set of secondary winding may output the current to the first rectifier that converts alternate current to direct current
Data Source
AI summary
An apparatus to provide welding power. The apparatus may include a direct current-alternate current (DC-AC) power converter to output a primary current and a transformer stage. The transformer stage may include at least one power transformer to receive the primary current from the (DC-AC) power converter on a primary side of the transformer stage and to output a first voltage through a first rectifier and a first set of secondary windings disposed on a secondary side of the transformer stage. The transformer stage may further include an auxiliary set of secondary windings disposed on the secondary side to output a second voltage. The apparatus may also include a pair of active unidirectional switches disposed on the secondary side to receive the second voltage from the auxiliary set of secondary windings.