“…The state variable model based on distributed‐parameter line also exists [17, 18]. For the solution of the state equations, the numerical integration methods are generally used and in these techniques a voltage or current source with any type of variation can be adopted easily [11, 12, 17, 18]. However, to determine the state of the system at a time, it is required to determine the state vector at all previous time steps in an increment by numerical integration time step and thus, the interval of discrete‐time steps may affect the accuracy.…”