A modular state variable approach to the electromagnetic transients problem

An efficient algorithm for investigating the electromagnetic traveling-wave phenomenon on an arbitrary power system is presented. Specifically, a modular state-variable approach is utilized to calculate the voltage and current traveling waveforms. Each component of the power system is modeled with its associated state variables. A method for decoupling these component equations is considered. A voltage source at the sending end of the transmission line models a disturbance to the system, while the voltage at the receiving end of the line varies according to a specified load. The transmission line is divided into an integer number of equivalent T-section segments, with the inductor currents and the capacitor voltages designated as state variables. The trapezoidal method of numerical integration is used to transform the state equations into a set of first-order difference equations. The resulting matrix equations are sparse, and techniques are used to exploit this fact