
AC-to-DC Three-Phase/Switch/Level PWM Boost Converter 12-41
and d represents the system response to a sudden increase then decrease of the mains voltage. e
same mains voltage disturbances are applied to the converter under unbalanced DC load operating
conditions. e corresponding results are shown in Figures 12.26 and 12.27 for a small (σ = 0.33) and
severe (σ = 0.82) load unbalance, respectively.
12.5.4 Comparative Evaluation
By inspecting Figures 12.21 through 12.24, we can deduce the following conclusions:
1. During the rated and balanced operating conditions (Figure 12.21), the nonlinear control oers
a better current shaping than the l ...