Asynchronous starting of synchronous machines with or without rectifiers in the field circuit

Synchronous machines in pumped-storage stations and in industry are very often run up asynchronously. This starting procedure can be treated within the scope of the 2-axis theory with modified equivalent diagrams, irrespective of whether the poles are laminated or solid. All solid-iron parts of the rotor are accounted for in the modified equivalent diagrams. When working with the conventional characteristic quantities of the synchronous machine (conventional equivalent diagrams), however, the calculated torque differs widely from the measured value, not only numerically but throughout the whole curve pattern. The method described here can also be used for brushless synchronous machines. On the basis of many experiments, the characteristic features of asynchronous starting with and without diodes in the field circuit are discussed and formulated in theoretical terms.