Simple nine-level inverter with 10 switches and a floating capacitor

This paper presents a simple nine-level inverter with 10 switches and a floating capacitor. The proposed inverter consists of a five-level activeneutral-point-clamped (ANPC) leg and an unfolding leg. The ANPC leg generates a pulsating AC waveform with five voltage levels. The unfolding leg operates at the grid frequency and unfolds the pulsating AC waveform to convert it into a nine-level waveform. Also, a floating capacitor voltage balancing algorithm is introduced to ensure voltage stability. To show the feasibility and performance of the proposed inverter, 1.5 kW prototype is developed.