Estudo de perdas em inversores alimentados por tensão pulsada no barramento de corrente contínua.

Abstract

This work aims to give a contribution to the study of pulsed DC link inverters. A comparative study is accomplished, considering several existent topologies and advantages and disadvantages of each circuit are observed. Pulse width modulation techniques are also analyzed, with conclusive considerations about synthesis of the output current sinusoidal waveforms in the inverter. Also, the digital implementation of some vector techniques is analyzed, the results being adequate for the operation of the pulsed link inverter. Such techniques are analyzed in relation to the RMS losses, taking into account the total losses in the system. The modulation to be considered is evaluated so that the inverters having capacitors in parallel with the main switches have larger operation stability. Obtained from models of IGBTs, inserted in basic test circuits, equations of losses are used in the simulation of the inverters. The equations of losses are used together with modulation techniques studied. The circuit and the proposed techniques are analyzed through simulation in which the influence of the main sources of losses is considered. Finally, simulated results for new proposed circuits, PWM techniques, and the technique for calculation of losses are corroborated by experimental results achieved for simulation conditions.