Transformer-Free Resistance Welding With Supercapacitor DC Control
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Solution Overview
Problem
Traditional electrical resistance welding systems face inefficiencies due to high inductive losses in transformers and resistive losses in DC rectifier diodes, leading to inconsistent welds and equipment maintenance challenges.
Innovation Solution
A welding system that uses a bank of supercapacitors and MOSFET-based switches to supply genuine DC current without diode rectification, allowing for precise control of welding voltage and current, eliminating the need for transformers and DC rectifier diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional transformer-based AC welding systems are used, then welding current can be obtained, but significant inductive losses occur in the transformer and cooling energy is wasted
Solution Approach 1:
The patent removes the transformer from the welding power supply system entirely, replacing it with a capacitor bank-based energy storage system. This extraction of the problematic transformer component eliminates inductive losses and the associated cooling requirements, directly resolving the energy loss issue while simplifying the overall system architecture.
Solution Approach 2:
The patent substitutes the electromagnetic transformer-based power conversion system with a capacitor bank-based electrical energy storage and release system. This replacement eliminates the mechanical cooling requirements and inductive losses associated with transformers, achieving the same welding current delivery function through a different physical mechanism.
2Loss of energy
If DC rectifier diodes are used to convert AC to DC, then direct current welding is achieved, but resistive losses occur in the diodes
Solution Approach 1:
The patent removes the DC rectifier diodes from the system by using a capacitor bank that naturally stores and releases electrical energy in direct current form. This extraction eliminates the resistive losses that occur in diode rectification circuits while maintaining the ability to deliver controlled DC welding current.
Solution Approach 2:
The capacitor bank is pre-charged to store electrical energy before the welding operation. This preliminary energy storage action allows the system to deliver high current without needing rectifier diodes during the actual welding process, thereby avoiding resistive losses in the diodes.
3Temperature
If transformers are used to step down voltage to low levels, then welding voltage control is achieved, but the transformer size becomes enormous and requires cooling fluid
Solution Approach 1:
The patent removes the bulky transformer from the system and replaces it with compact capacitor banks that can be charged to the required voltage levels. This extraction eliminates the need for enormous transformer sizes and associated cooling systems, achieving voltage control through capacitor charge voltage regulation instead.
Solution Approach 2:
The patent controls welding voltage by changing the charge voltage parameter of the capacitor bank rather than using transformer turns ratios. This parameter change approach allows for compact, lightweight voltage control without the need for large transformers and cooling infrastructure.
4Reliability
If AC welding with transformers is used, then welding current is obtained, but the system requires frequent maintenance and has reliability issues
Solution Approach 1:
The patent removes the transformer and rectifier diodes—the components requiring frequent maintenance—from the welding system. By replacing them with solid-state capacitor banks and MOSFET switches, the system achieves improved reliability and reduced maintenance needs, as capacitors and modern semiconductor devices have longer operational lifetimes and fewer failure points.
Solution Approach 2:
The patent employs solid-state electronic components (capacitors and MOSFETs) that, while having finite lifetimes, offer superior reliability and easier replacement compared to large transformers and rectifier assemblies. These components are more durable, require less maintenance, and can be replaced more easily, improving overall system reliability and ease of repair.
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 system enables efficient, consistent, and reliable welding with precise control over welding parameters, reducing equipment size and maintenance needs, and improving weld quality.
Implementation Method 1
a bank of capacitors, such as electrolytic capacitors or supercapacitors... The capacitor bank is charged to any voltage between 0 and 12 volts... Current supplied by the capacitor bank is genuine DC
Implementation Method 2
a MOSFET or another transistor-based weld switch... The switch transitions from an off-state to an on-state... transitioning the switch from an off state to an on state is accomplished by a semiconductor
Implementation Method 3
electrical resistance welding assembly... welding a work piece with direct current in the electrical resistance welding assembly
Data Source
AI summary
Components of an electrical resistance welding system include a DC power supply, an energy storage assembly, a switch, and an electrical resistance welding assembly configured to weld a work piece. The system may be free of any transformer which permits the system to operate in an infinite number of variable voltages between a minimum and maximum system setting. The variable voltage control permits greater operability of the electrical resistance welding system by creating a specific weld voltage dependent on parameter, such as a dimension, of the work piece that is to be welded.