SVPWM for Five-Level Active Neutral-Point-Clamped Converter Based on Multispace Voltage Vector Mapping and Midpoint-Voltage Self-Balancing Strategy

This article proposes a space vector pulsewidth modulation using space voltage vector mapping and the midpoint-voltage self-balancing strategy to overcome the shortcomings of the existing active neutral-point-clamped five-level inverter modulation. Through multispace mapping, the five-level topology is converted into multiple two-level topologies for calculation. It greatly simplifies the computational burden. By adopting the midpoint-voltage self-balancing strategy, the midpoint-voltage self-balance is achieved, since the switching sequence of different sectors compensates each other for balancing the midpoint voltage. Therefore, this algorithm realizes that there is no or only a minimum number of switch tube actions when the reference voltage vector swaps different sectors. It reduces the switching loss and effectively avoids equipment damage caused by the simultaneous switching of multiphase switches. In addition, it also realizes the floating-capacitor voltage control by reasonably distributing the redundant switch states. Simulations and experiments verify the effectiveness of the proposed method.