Dynamic performance and control of a multilevel universal power conditioner

This paper presents the development of a control scheme for a multilevel diode-clamped power converter connected in a series-parallel fashion to the electrical system such that it can compensate for deviations in utility voltage (sag, surge, and unbalance) and act as a harmonic and/or reactive current source for a load. New carrier-based multilevel pulse width modulation (PWM) techniques are identified to maximize switch utilization of the two back-to-back diode-clamped inverters that constitute the universal power conditioner. An experimental verification for a 6-level power conditioner is given.