PROJECT TITLE :

Ac-Dc-Ac Single-Phase Multilevel Six-Leg Converter with Reduced Number of Controlled Switches - 2017

ABSTRACT:

This paper proposes 2 unidirectional single-phase ac-dc-ac converters with a reduced number of controlled switches composed of 2 3-leg converters connected in series. The proposed converters enable us to feed the load voltage with sinusoidal voltages with constant amplitude and frequency and to work with sinusoidal grid current with a high power factor. The converters will then be used as uninterruptible power supplies and unified power quality conditioners for nonregenerative applications. The system model, area-vector pulse width modulation technique, and a whole control system are given. A methodology to control the dc-link voltages using the voltage vector redundancies is presented. The proposed topologies are compared with the standard one in terms of operation range, capability to operate with a unity grid power factor, voltage harmonic distortions, semiconductor losses, and others characteristics. Simulation and experimental results in many operating conditions are provided to validate the feasibility of the system.