New approach to switch modelling in the analysis of power electronic systems

A new and efficient approach for the analysis of power electronic circuits using the modified nodal formulation of circuit equations is presented. The method is well suited for the development of dedicated simulation software for power electronic systems. Semiconductor switches are modelled as binary inductors, as a very low value of inductance (determined by the rating of the semiconductor) during conduction, and infinite value of inductance otherwise. The system matrix is partitioned in such a manner as to permit efficient handling of switch status. The method can be easily adapted to incorporate control circuits and machine representations. The backward Euler method of integration is used for the solution of equations to ensure convergence. Examples of regulator and inverter circuits are solved using the new approach and results are included