Patent EP-2216124-B1 (EP)
Inventor: AIGNER HUBERT
IPC: B23K9/095
Filed: 2010-01-29
Granted: 2013-12-25
Abstract: The method for regulating a welding power source with a transformer (30) that has a serial oscillating circuit at primary side and a parallel oscillating circuit at secondary side, comprises providing the serial oscillating circuit by a bridge circuit with a variable alternating voltage and providing energy to welding process by the parallel oscillating circuit over a rectifier, where a control unit (25) controls the bridge circuit in dependent upon a state variable of the welding power source. The control unit brings a control signal dependent of primary power or state variable. The method for regulating a welding power source with a transformer (30) that has a serial oscillating circuit at primary side and a parallel oscillating circuit at secondary side, comprises providing the serial oscillating circuit by a bridge circuit with a variable alternating voltage and providing energy to welding process by the parallel oscillating circuit over a rectifier, where a control unit (25) controls the bridge circuit in dependent upon a state variable of the welding power source. The primary power or a state variable corresponding to the primary power detects as power-state variable of the welding power source. The control unit brings a control signal dependent of primary power or state variable. The primary power or the state variable corresponding to the primary power regulates on equally remaining amplitude. The welding power source detects the resonance frequency as further operating size and corrects the value of the detected primary power or the state variable in dependent upon the resonance frequency. The arc resistance determines the welding process from the detected resonance frequency and the detected value of the primary power or the state variable corrects in dependent upon the arc resistance. The phase angle between the secondary power of the transformer and the welding power and the detected value of the primary power or the state variable correct in dependent upon the phase angle. The table value of the resonance frequency and the phase angle is stored in dependent upon the arc resistance in a storage member (70) for a given dimensioning of the welding power source and the assigned value of the arc resistance and/or the phase angle obtain from the storage member for the detected value of the primary power or the corresponding state variable at the primary side for a detected value of the resonance frequency. The detected value of the primary power or the corresponding state variable at the primary side multiplies with the cosine of the phase angle. The output voltage of the welding power source adjacent at the output of the rectifier detects as further state variable. The value of the detected primary power or the state variable corrects in dependent upon the output voltage for forming a control signal for the control unit. The corrected value of the primary power or the state variable inputs as actual value in a regulation, whose desired value is determined in the form of the welding power of the user. An independent claim is included for a welding power source.