Arc welding set powered by asynchronous generator - has excitation capacitors shunted by primary winding of transformer which saturates when on no load

摘要

The application is to prime mover powered welding sets using an asynchronous generator with capacitor excitation. The proposed connection of the transformer is intended to assist in limiting the required size of the generator. The asynchronous generator (11), driven by an internal combustion engine (10), has excitation capacitors (19) connected in parallel across the terminals. The necessary reactors for compensation are formed by connecting the primary windings (12) of the welding transformer (13) in parallel with the capacitors. The transformer core is designed to saturate sharply at, or slightly above, the nominal generator no load voltage. The design and connection limits the no load voltage to a suitably low value, and at the same time ensures that, when on load, an adequate welding current is available. The welding transformer output is typically rectified (15).