Simulation of active power filters using switching functions

The operation of static power converters used in active filters can be simulated by means of widely available circuit simulation software packages such as PSpice. In these studies, converters are usually modeled as a set of real or idealized switches, which may result in long execution times and possible convergence problems, particularly in complex circuits. This paper proposes the use of macromodels to simulate active filters. The macromodels are based on converter switching functions rather than actual circuit components, and they are well suited for steady state and large signal transient analysis at the system level. In this approach, the converters are simulated as multiport networks avoiding the physical nonlinear micromodels associated with power switches. Computer memory and execution times required for the simulation of the power circuit are thereby significantly reduced. The procedure also allows rapid design of filter components, in particular passive elements such as inductors and capacitors. Complete examples of typical shunt filters are given to illustrate the effectiveness of the proposed models.