Analysis of DC harmonics using the three-pulse model for the Intermountain Power Project HVDC transmission

The authors compare the `classical´ converter modeling technique described by E.W. Kimbark (1971) and the recently proposed three-pulse model described by N.L. Shore et al. (1988). The comparison is made for the Intermountain Power Project (IPP) HVDC (high-voltage direct current) transmission. Comparisons with field measurements show that both the disturbance level and the spectrum of the harmonics are correctly modeled by the three-pulse method. Furthermore, observed changes in the disturbance level caused by changes in the DC circuit and operating conditions have been reproduced by the new model. It is noted that some discrepancies between the model and the measurements exist for individual harmonics, but these differences are generally small and can be explained by assuming realistic variations in certain parameters. The three-pulse model is an improvement over the traditional methods used in this type of analysis, and is sufficiently accurate for use in further DC harmonics calculations