Grid-Connected Resonance Suppression Of Group-Series Photovoltaic Cluster Inverters Based On Hybrid Damping

Abstract

Grid-connected group-series photovoltaic cluster inverter system will cause resonance, which will adversely affect the system. To suppress grid-connected resonance, the mathematical model, resonance mechanism and resonance characteristics of the cluster inverters are analyzed, and a global resonance suppression strategy based on hybrid damping is proposed. In the current loop of the inverter, capacitive current feedback and parallel voltage proportional feed-forward are introduced as active dampers to reduce the harmonics of the parallel current. On this basis, RLC type second-order resonance suppression circuit is added as passive damping to suppress system resonance, so that the output current of the inverters can meet the grid-connected conditions when the cluster is connected to the grid. The simulation and experimental results show that the total harmonic distortion of the grid-connected current decreases from 10.54% to 1.97% after three series photovoltaic cluster inverters adopt this strategy, which effectively suppresses the grid-connected resonance.

Investigation of novel control strategies for grid-connected photovoltaic inverters

“…Comparative analyses extend beyond control strategies to the architectural realm, evaluating the performance and applicability of two-and three-level inverters in grid-connected photovoltaic systems, thus providing a comprehensive understanding of the trade-offs and synergies between different system designs [18]. The emphasis on power quality and grid compatibility is further evident in strategies aimed at resonance suppression in photovoltaic cluster inverters, underscoring the industry's commitment to ensuring seamless integration of renewable sources into the power grid [19]. As we traverse the intricate landscape of grid-connected photovoltaic inverters, the focus is unequivocally shifting towards advanced, intelligent, and adaptive control strategies.…”