Projekter pr. år
This paper investigates the active damping of LCL-filter resonance within single-loop grid current control of grid-connected voltage source converters. First, the basic analysis in the continuous s-domain reveals that the grid-current-feedback active damping forms a virtual impedance across the grid-side inductor, and the use of a high-pass filter with a negative sign shapes the virtual impedance by an RL damper paralleled by a negative inductance. It is further found that such a negative virtual inductance plays a critical role in mitigating the phase lag caused by the time delay in a digital control system. The instability induced by the negative virtual resistance, which is commonly experienced in the feedback-type active damping, can thus be avoided. A systematic design method of the highpass filter is also proposed by the help of root locus analysis in the discrete z-domain. Lastly, experimental tests are presented to validate the theoretical analysis.
|Titel||Proceedings of the 2014 IEEE Energy Conversion Congress and Exposition (ECCE)|
|Status||Udgivet - sep. 2014|
|Begivenhed||2014 IEEE Energy Conversion Congress and Exposition (ECCE) - Pittsburgh, Pittsburgh, USA|
Varighed: 14 sep. 2014 → 18 sep. 2014
|Konference||2014 IEEE Energy Conversion Congress and Exposition (ECCE)|
|Periode||14/09/2014 → 18/09/2014|