DROOP CONTROL STRATEGY USING RESONANT CONTROLLERS TO ACHIEVE RESISTIVE OUTPUT IMPEDANCE CHARACTERISTICS FOR UPS INVERTERS

CARBALLO, ROBERTO ESTEBAN; BOTTERÓN, FERNANDO; OGGIER, GERMÁN GUSTAVO; GARCÍA, GUILLERMO OSCAR

Juiz de Fora

Congreso; Congreso Brasilero de Electrónica de Potencia 2017; 2017

Facultad de Ingeniería de la Universidad Federal de Juiz de Fora

A droop control strategy to achieve parallel operation of single-phase inverters for UPS applications is proposed in this work. This strategy is based on multipleresonant controllers designed to comply with performance specifications given by IEC62040-3. In order to reduce the circulating current between the parallel connectedinverters, the inverters output impedances must be increased. For this purpose a damping factor in the resonant controller tuned at the fundamental frequency isproposed. A design criteria for this damping factor is proposed based on a state-space model of the whole UPS system. Experimental results are presented to validate theproposal.