Efficiency evaluation of various assemblies of variable speed drive

The paper presents results of experimental measurements of efficiency of variable speed drive assemblies and their analyses. These configurations of the drive have been tested: without any filtering devices, with an input AC reactor and broadband passive harmonic filters, and with output filtering, such as output reactor or sine-wave filter, respectively. These filtering devices are used to match the requirements of drive electromagnetic compatibility; nevertheless, they have an influence on drive efficiency. An assumption of drive efficiency decrease in the case these devices were used was confirmed and analyzed in this paper. Efficiency of individual units of the variable speed drive is also shown.