The speculative method of transient state analysis with a variable integration step

In the article the speculative method of the analysis of transient states appearing in systems described by a large system of linear or nonlinear ordinary differential equations is presented. This method is based on decomposition of the total time of the transient analysis on a given number of subintervals, in which computations are conducted in parallel with the use of one of wellknown numerical methods of solving ordinary differential equations system. In previous papers (2001) the application of the fourth-order Runge-Kutta method with a fixed integration step was presented. In this paper the application of the same method, but with a variable integration step, is shown. The change of the method allows one to reduce the time of computations, but requires a new method of determination of initial conditions in particular subintervals and a new method of division of the total time of transient state analysis to be worked out. As an example of application, the analysis of dynamics of an asynchronous slip-ring motor is presented.