A Fast Algorithm for LU Decomposition of a Large Sparse Matrix in an Electromagnetic Transient Analysis Program

Abstract

For electromagnetic transient (EMT) analysis programs, faster simulations are always desired, since circuits to be simulated are becoming larger and larger. This paper proposes a non-zero element combination recording algorithm for fast search for non-zero elements in the LU decomposition of a large sparse matrix obtained from circuit equations. It should be noted that the solution process of the circuit equations occupies a large portion of the total simulation time. A sparse matrix routine with the proposed algorithm has been developed. In a simulation case with a synchronous generator model which requires frequent LU decompositions, the developed routine is faster by 1.5 times than the conventional one.