Abstract
This paper presents some extensions for Combined Iterative Method (CIM) based on Modified Predictor-Corrector Iteration (MPCI) and Newton Raphson Iteration (NRI) to extend Electromagnetic Transient Simulation for including nonlinear elements in an electrical network solution. It is important to adopt an iterative method optimally in CIM to improve convergency, because a solution obit depends on a multi-dimensional plane between initial and real solutions. An effective construction of MPCI and Jacobian matrices based on a multi-dimensional solution with Dommel's method, and an effective expression of MPCI and NRI on EMTP-Type simulators have been also proposed to realize a high accuracy, high stability and saving a calculation time simultaneously for any kinds of circuits, Some examples are demonstrated using the proposed algorithm, and the results are compared with those by a basic nodal conductance approach (NCA), EMTDC/PSCAD solutions and measured results. The comparison proves the validity of the proposed methods, which is applicable to EMTP-Type simulators to solve a nonlinear circuit.
