Affiliation of Author(s):自动化学院
Journal:IEEE TRANSACTIONS ON POWER ELECTRONICS
Key Words:Active-damping proportional-integral-resonant (PIR) regulator second harmonic current (SHC) two-stage single-phase inverter
Abstract:The instantaneous output power of the two-stage single-phase grid-connected photovoltaic (PV) inverter pulsates at twice the line frequency (2f(o)) generating second harmonic current (SHC) in the front-end dc-dc converter and PV panel, which will affect the maximum power point tracking operation and deteriorate the overall conversion efficiency. The generating mechanism of the SHC is analyzed in this paper and it is pointed that in order to eliminate the SHC in the front-end dc-dc converter and PV panel, the voltage loop gain of the front-end dc-dc converter should be high enough at 2f(o). Since there is a -180 degrees phase abrupt at the resonant frequency of the input side filter capacitor and the inductor, the system may be unstable. To cope with this problem, the inductor current feedback active-damping scheme (ADS) is adopted. For further improving the loop gain at 2f(o), proportional-integral-resonant regulator with ADS (PIR + ADS) is proposed in this paper. Besides, a step-by-step closed-loop parameters design method is presented. Finally, a 3-kW two-stage single-phase grid-connected PV inverter has been fabricated and tested, and the experimental results verify the feasibility of the proposed control schemes.
ISSN No.:0885-8993
Translation or Not:no
Date of Publication:2019-07-01
Co-author:Kan, Shiqi,Dang, Hao,Zhang, Li,dcl,Huang, Xinze
Correspondence Author:rxb
Date of Publication:2019-07-01