Sang-Won An and Kyo-Beum Lee, "A Reliability Improvement Method for Three-Level Inverters with Modified VSVPWM," in Proc. WoW Conf., Nov. 2020. > Paper

This paper proposes a novel virtual space vector pulse width modulation (VSVPWM) method for reliability improvement of the three-level 

inverters. To create the neutral point, the DC-link in the three-level inverters is divided into two capacitors. The split DC-link capacitors 

induce a drawback which is AC unbalance between each DC-link voltage of capacitors. To mitigate this drawback, VSVPWM was widely

researched. The VSVPWM controls the neutral point (NP) AC ripple voltage to zero within one switching period. However, VSVPWM 

does not consider the NP ripple current and CMV. The NP current equals to the sum of each capacitor currents. Its large ripple 

component increases the core temperature in capacitor, which reduces the lifespan of the DC-link capacitors. Additionally, CMV with a 

large peak-to-peak value generates the electro-magnetic interference issues and leakage current. In this paper, an optimized VSVPWM

for suppressing the capacitor ripple current and the variation of CMV is proposed. The effectiveness and validity of the modified 

VSVPWM are verified with various simulation results.