Abstract
This paper presents a new DC-AC Interconnected Modular Multilevel Converter (IMMC). The proposed converter produces a sinusoidal output with adjustable voltage and frequency (v/f) suitable for powering AC motor drives. The output voltage/frequency can be varied over a wider range. The proposed converter is a promising candidate for high performance ac motor drives and has the following advantages: sinusoidal output voltage with v/f control; no acoustic noise; low EMI; absence of dv/dt related issues due to long motor leads; compact size/weight/volume. The proposed converter is modular in construction, employs high frequency L-C components and can he stacked for voltage sharing. The paper details the operating modes, control aspects along with an illustrative design example for a three and eleven module converter. Experimental results on a laboratory prototype converter employing 600V GaN devices are discussed.