An interactive program to determine the harmonics produced by an AC-DC converter

The paper presents an application of a general purpose interactive program useful to analyse the steady-state behaviour of power systems including static converters. In particular the program has been adapted to determine the harmonics introduced by an AC-DC converter in an electric distribution system. Beginning with a description of the system structure and the actual values of its parameters, the program at first determines the kind of conduction (continuous or discontinuous) and, subsequently, the steady-state values of the system state variables at an SCR turn-on instant. Therefore the program is ready for the computation of several features characterizing the steady-state behaviour. After the description of the main characteristics of the program and the power system, the paper shows how the program is able to determine the mean values and the harmonic coefficients of the most significant quantities and verify the stability of the power system.