Real-time implementation of three-phase single-stage SPV grid-tied system using TL-VSC

This work deals with real-time implementation of a three-phase single-stage solar photovoltaic (SPV) grid-tied system using a three-level voltage source converter (TL-VSC) working at lower switching frequency of 900Hz under varying solar intensity levels for large power applications. The proposed system consists of SPV array, TL-VSC, interfacing inductors, and three-phase AC grid. The decoupled current controller with the capacitor voltage balancing control and an incremental conductance maximum power point tracking (IC-MPPT)-based algorithms are used to control the TL-VSC to track and transfer maximum active power to AC grid at unity power factor from SPV array. Owing to low switching frequency and single-stage topology, the efficacy of the system is increased. The performance of SPV grid integrated system using TL-VSC is validated under varying solar intensity levels in the laboratory at different switching frequencies and interfacing inductors in accordance to IEEE 519 standard.