Linearization and Overmodulation of an 18-sided Voltage Space Vector based Converter using a Switched Capacitive Filter

In this paper, a novel 18-sided voltage space vector pulse width modulation (SVPWM) scheme for open-end winding induction machines, utilizing two 2-level inverters and a single DC source, is proposed. The proposed scheme achieves enhanced DC-link utilization, reaching up to 98.9% in the linear region, and eliminates low-order harmonics during extreme 18-step modulation. By carefully selecting the switching vectors, the DC link capacitor voltage of the capacitor-fed inverter is naturally regulated without requiring a closed-loop controller. The mathematical analysis is presented and validated through experimental results, demonstrating the feasibility and effectiveness of the proposed SVPWM scheme, maintaining capacitor voltage stability and delivering improved performance.