Non-iterative nodal solution for transient simulation of nonlinear and time-varying elements

A non-iterative algorithm based on nodal equation formulation is proposed for transient simulation of nonlinear and time-varying elements. Terminal equations of inductors and capacitors are transformed into algebraic equations using the trapezoidal rule of integration by treating all nonlinear elements as linear and nodal equations are formulated as a set of algebraic equations. LU factorization is used for the solution of nodal equations. Variation of system elements is represented by renewing the nodal conductance matrix at each time step of the solution accordingly. In the first illustrative example, a nonlinear oscillator circuit is considered. In the second, the transient response of a transmission line with a surge arrester is computed by including the corona effects and in the third, a time-dependent primary arc model of a faulty transmission line is examined. Obtained results are compared with those obtained using EMTP and state-space method. Change of simulation time with respect to the step length of the numerical integration is also investigated.

► A non-iterative algorithm is proposed for transient simulation of nonlinear and time-varying elements.
► Terminal equations of inductors and capacitors are transformed into algebraic equations.
► Variation of system elements is represented by renewing the nodal conductance matrix at each step.
► Power systems with several nonlinearities are studied.
► The method is found efficient in computing transient response of systems with nonlinear elements.