The vector diagram of the synchronous induction motor, and some operating characteristics

Mr. President and gentlemen, the increasing importance attached to the improvement of the power factor of supply systems has led to the extensive use of synchronous machinery. The efforts of inventors and manufacturers have been directed mainly against that greatest drawback of synchronous motors, their poor starting characteristics. The result has been the appearance of a number of self-starting synchronous motors, of various types, the two here noted being known as induction type synchronous motors, or synchronous induction motors: