Arc welding power supply

Arc welding power supplies need to meet special requirements due to their working characteristics (such as dynamic changes in arc load, process stability requirements, etc.), mainly involving electrical performance, dynamic response and safety. The following is a specific analysis:

1. Reasons for special requirements for arc welding power supplies
Arc load characteristics
The arc is a nonlinear dynamic load with a complex voltage-current relationship, requiring the power supply to quickly adapt to instantaneous changes (such as short-circuit-open circuit switching during arc initiation and droplet transition).

Process stability requirements
Welding quality depends on arc stability, and the power supply needs to suppress current/voltage fluctuations to avoid defects such as arc breaking, spatter or unfused.

Material and process diversity
Different welding materials (such as aluminum, steel) and processes (MIG/MAG, TIG, manual welding) have differentiated requirements for power supply external characteristics (constant current/constant voltage), waveform control (pulse, AC frequency), etc.

Energy efficiency and thermal management
Long-term high-load operation requires efficient heat dissipation design to avoid overheating damage and improve power utilization.

2. Core requirements of arc welding power supply
1. Electrical performance requirements
External characteristics matching
Constant current characteristics: used for manual arc welding (MMA) and TIG welding, to ensure current stability, and voltage adaptation when arc length changes.
Constant voltage characteristics: used for MIG/MAG welding, to maintain voltage stability, and current automatically adjusts with wire feeding speed.
No-load voltage: needs to be high enough (usually 50~80V) to reliably start the arc, but must comply with safety standards (such as IEC 60974-1).
Dynamic response speed: The recovery time during short-circuit transition needs to be <1ms (such as CO₂ welding) to avoid droplet adhesion.
2. Control function requirements
Waveform modulation capability
Pulse welding requires high-frequency current regulation (such as 100-500Hz), and aluminum welding requires AC square wave (50-200Hz) to break the oxide film.
Parameter adjustable range: Current and voltage need to be continuously adjustable over a wide range (such as TIG welding 5~300A) to adapt to materials of different thicknesses.
3. Structural and environmental adaptability
Protection level: Industrial environment needs to be IP23 or above, dust and splash proof; field operation needs earthquake-resistant design.
Cooling system: air cooling (lightweight) or water cooling (high power) to ensure continuous operation.
4. Safety and compatibility
Anti-electric shock protection: no-load voltage reduction device is required (such as VRD function, which drops to below 24V after arc initiation).
Electromagnetic compatibility: suppress high-frequency interference to avoid affecting peripheral equipment (comply with EN 61000 standard).
III. Additional requirements for special processes
Digital control: high-end power supplies need to support multi-parameter storage and network monitoring (such as IoT interface).
Energy feedback: energy-saving power supplies can feed braking energy back to the power grid (such as inverter power supply).
Summary
The design of arc welding power supply needs to balance dynamic response, process adaptation and reliability. Modern inverter technology (high-frequency switching) has greatly improved performance, but the core is still centered on "stable arc, efficient output, and safe operation". The actual selection needs to be comprehensively evaluated based on welding methods, materials and working conditions.