imulation of Three-phase Transformerless Online UPS using MATLAB/SIMULINK

Abstract

This paper explicate the modeling and simulation of an alternate configuration to the conventional
transformer based online Uninterruptible power supply(UPS). It proposes a transformerless three phase online UPS with
power factor correction. The proposed model consists of Battery bank, half-bridge rectifier, Auxiliary circuit , Split DC bus
and an inverter. Auxiliary circuit consists of switching leg(low rating) and an inductor , employed for charging the battery
bank during normal operation of UPS and also to maintain the DC bus capacitors voltage during backup operation. This
configuration adds the advantages by reduction of overall size, cost and weight of the system. The system is modeled and
simulated using MATLAB/SIMULINK. Detailed control design, circuit operation with the simulation results have been
presented in paper for verification of its feasibility and behavior