A compact representation of synchronous motors and unregulated synchronous generators

The development of compact methods for modeling synchronous machines in two modes of operation-as synchronous motors and as unregulated synchronous generators-is discussed. The advantage of the new representation is that, in spite of its compactness, it describes fairly accurately the features of the machines and preserves their three-phase dynamic behavior, directly at the line frequency. The models are expected to assist in recent developments of special power systems with many small generators, and it should be also helpful for recently discussed applications in control of synchronous motors. The suggested models are also capable of directly representing permanent magnet machines. The digitally simulated models´ results compare favorably to experimental system results.