Dynamic analysis of synchronous motor using vector diagrams-na  intuitive approach

Lobosco, Orlando Silvio.
Inst. of Electrotech. & Energy, Sao Paulo Univ., Brazil

Abstract:
Vector diagrams have been used for many years to help understand the physical behavior
of electric machines and to give geometrical answers to a number of machine operating
problems. Vector diagrams for a synchronous machine in steady operational conditions or
even at the first instant of a transient state are a quite common means of analyzing the
machine performance. This paper shows the application of vector diagrams to represent
the behavior of a synchronous motor during a transient process. As an example, the
dynamic power diagram is introduced, showing the oscillation of the rotor following a
sudden change in the motor operation. The intention of the paper is also to point out the
contribution of the intuitive mind to the solution of technical problems, usually neglected
in our educational system. It is the author's belief that the visualization obtained from
geometric constructions is particularly useful for teaching purposes, since nowadays, the
widespread use of computers to solve numerically the machine equations tends to divert
the student's attention from the actual physical phenomenon occurring during the
performance of the electrical machines.