Solution of transient-stability problems through the number-series approach

The paper presents a numerical method for the solution of transient-stability problems utilising the number-series approach. Significant generator characteristics which are normally neglected, such as transient saliency, field decrement and damping, are included in the transient-stability study. The swing equation is arranged in a block-schematic form separating the linear and nonlinear parts. Data for the swing curve are obtained from convolution of the impulse response of the linear block with its input; the convolution integral is evaluated by standard numerical methods such as the trapezoidal and Simpson´s rules. Rational bases are presented for the selection of a suitable time increment for a specified accuracy. The results obtained by the number-series method are compared with those of the fourth-order Runge-Kutta method. Finally, general hints and suggestions are given for programming the number-series method on a digital computer.