Comparison of Medium Voltage IGBT-based 3L-ANPC-VSCs

Recently the 3L-ANPC-VSC was introduced to overcome the unequal loss distribution and the resulting unsymmetrical semiconductor junction temperature distribution as main structural drawback of the 3L-NPC-VSC. This paper compares conventional 3L-NPC-VSCs with 3L-ANPC-VSCs using 3.3 kV, 4.5 kV, and 6.5 kV IGBT modules for industrial Medium Voltage Drives for rated converter output voltages of V_LL = 2.3 kV, 3.3 kV, and 4.16 kV in a switching frequency range of f_s = 300 Hz to 1050 Hz. Maximum achievable converter power, converter efficiency, switch utilization, active silicon area and material costs are determined and compared for given IGBT and diode modules. The comparison is the basis for a derivation of advantageous operating conditions of 3L-NPC-VSCs and 3L-ANPC-VSCs.