Turbo-generator performance under exceptional operating conditions

A series of tests was made to determine the performances of a normally inactive and a continuously acting turbo-generator automatic regulator, and the opportunity was also taken to check some operating conditions which do not often arise in normal service. The paper gives typical details of tests on a generator operating at considerable leading power factors with different excitation-control systems. Instances of instability and out-of-step running occurred and were recorded, as also were tests on the machine as an asynchronous generator at various slip frequencies. A method of synchronizing, previously discussed but not tested and recorded in this country, was used in which the running generator was connected to the busbars and the excitation applied after a time interval. Conclusions arising from the investigations are given.