Title : 
Design of virtual inductance for droop-controlled inverter with seamless transition between islanded and grid-connected operations
         
        
            Author : 
Hu, Shang-Hung ; Kuo, Chun-Yi ; Lee, Tzung-Lin
         
        
            Author_Institution : 
Dept. of Electr. Eng., Nat. Sun Yat-sen Univ., Kaohsiung, Taiwan
         
        
        
        
        
        
            Abstract : 
A seamless transition method has been presented for a droop-controlled inverter to transfer between islanded and grid-connected operations. A so-called virtual inductance and local phase-locked-loop (PLL) were proposed to realize this transition with no grid synchronization. This paper presents designing of variable virtual inductance to suppress inrush current, including exponentially-decaying, ramp-decaying, and constant virtual inductances. In addition, phase error of the PLL and the transient of the droop control are included. Simulations and preliminary experiments are provided.
         
        
            Keywords : 
distributed power generation; invertors; phase locked loops; power grids; PLL; droop-controlled inverter; exponential-decay; grid synchronization; grid-connected operation; inrush current suppression; islanded operation; phase error; phase-locked-loop; ramp-decay; seamless transition method; variable virtual inductance design; Delay; Inductance; Inverters; Phase locked loops; Surges; Switches; Voltage control;
         
        
        
        
            Conference_Titel : 
Energy Conversion Congress and Exposition (ECCE), 2012 IEEE
         
        
            Conference_Location : 
Raleigh, NC
         
        
            Print_ISBN : 
978-1-4673-0802-1
         
        
            Electronic_ISBN : 
978-1-4673-0801-4
         
        
        
            DOI : 
10.1109/ECCE.2012.6342226