Computer Algorithm For Synchronous Motors During Fault Operation

Synchronous motor is mainly used as a generator. In modern society, AC power supply is almost generated by the synchronous generator. The motor short-circuit would cause serious damage to the motor and the power grid, so it is of great significance to study on it.In the past, the research on the transient state process of synchronous motor after a sudden short-circuit is built on the stator three-phase axis. The resulting equation is a matrix differential equation with time-varying coefficients, whose solving process is very difficult. Its derived analytical formula contains many variables which are taking their approximate values, so that the results are not accurate.Since in the 1920s several coordinate transformation theories were proposed, the viewpoint of analyzing motor has turned to rotary coordinate system from the stationary coordinate system, such as Piker Transformation, so as to obtain simple and recipient state space equation. With these theories computer analysis on transient process of synchronous motor has a rapid growth.Based on analysis of coordinate transformation theory, this paper focus on solving the state space equation of the short circuits, of which mathematical model is more simple. And the results will be more accurate and less time-consuming. Moreover, in order to be a useful analytical tool, the software designed by the author is customer-oriented with a friendly portable interface, which is simple to use. The users who don't have a very clear understanding of the transient process of the motor can achieve the results of different transient process easily.