Development of calculation toolbox for harmonic estimation on multi-pulse drives

Using multi-pulse converters has become a common practice in order to minimize the harmonics in applications with large non-linear loads where the harmonics must be kept under certain limits. Even the harmonic mitigation performance of a multi-pulse drive is far superior to the well-known 6-pulse drive also the costs are increasing. Therefore, a proper assessment of the harmonic performance before commissioning is a necessity. This assessment is possible in many ways, one being with the help of specific software tools that allow comparisons of different topologies, in the same base of analysis (i.e. considering the same system diagram, the same input parameters, loads, etc.). This paper presents a method to integrate the 12-pulse and 18-pulse drives into a harmonic calculation toolbox dedicated for harmonic analysis on 6-pulse drives. The results are linked together into a practical PC software toolbox for harmonic estimation. By using a combination of a pre-stored database and a new interpolation technique the toolbox can provide the harmonic data on real applications allowing comparisons between the aforementioned mitigation solutions.