Design and implementation of a 3-phase voltage stabilizer using 11-level voltage source inverter

Transient power dip is not allowed in certain electrical appliances. This paper presents the design and the implementation of a 3-phase voltage stabilizer using an 11-level voltage source inverter. The voltage source inverter comprises of many identical single-phase inverters. Each inverter as a modular unit has a charged capacitor as its DC source. The number of modular units is determined by the number of voltage levels required. For this project, 5 units per phase are designed which generate 11-levels. Under normal power conditions, the stabilizer is in a floating state with the capacitor fully charged. When a voltage drop is detected at the mains terminals, the stabilizer is activated. The control of the stabilizer is realized by using a TMS320C50 digital signal processor. Optimized switching times for different voltage levels are calculated off-line. Experimental results show the feasibility of this approach.