2021-07-28
6.153
10.1109/TPEL.2020.2990923
IEEE Transactions on Power Electronics
Inverters; Capacitors; Maximum power point trackers; Voltage control; Power harmonic filters; Capacitance; Double-frequency ripple; maximum power point tracking (MPPT) performance improvement; parameter optimization design; second-order sliding mode control (SOSMC); single-stage single-phase photovoltaic (PV) system
Due to the inherent double-frequency (2f0) ripple in single-stage single-phase photovoltaic grid-connected inverters, the maximum power point tracking (MPPT) will inevitably be affected. To improve the MPPT performances, a passive LC power decoupling circuit with a robust second-order sliding-mode control (SOSMC) is thus proposed in this article. With the passive LC decoupling path, the double-frequency pulsation on the dc link is effectively cancelled out. Thus, the MPPT accuracy is significantly enhanced, and the utilization of a small dc-link capacitor becomes possible. However, resonance between the LC circuit and the main dc-link capacitor may appear, which can be damped through an active damping method. Additionally, the proposed SOSMC ensures good steady-state, dynamic performance (voltage fluctuation and settling time), and the robustness of the dc-link voltage, which is also beneficial to MPPT control in terms of high accuracy and fast dynamics. The systematic design of SOSMC is presented, and a detailed parameter optimization design of LC decoupling circuit is discussed. Experimental tests are performed on a 2.5-kW single-stage single-phase grid-connected inverter, and the results validate the effectiveness of the proposed strategy.
Su, Mei, Wang, Hui, Liu, Bin, Zhang, Xin, Pou, Josep, Yang, Yongheng, Davari, Pooya
Guo, Bin
Journal paper
Sun, Yao
20203509110990
Engineering
Electrical Engineering
35
12
13000-13016
08858993
no
2020-12-01
SCI、EI