Modular multi level inverter with self-healing power unbalancing capability in single stage solar PV systems

The trend of generating electrical power through renewable energy sources increasing day to day to reduce the burden on fossil fuel sources due to advancements in power electronics and materials sciences, which leads to efficient and effective power extraction. Role of inverters in a single stage power processing units is inevitable, includes power conversion, synchronization, active and reactive power control and maximum power point tracking. In such systems there may be a chance of power unbalance due to partial shading conditions and different ambient parameters of various panels leads to unbalanced load/grid currents. To address this issue, zero sequence voltage injection method is incorporated in feed forward manner of the closed loop system. The simulation results reveal that implemented algorithm successfully working for uneven string powers to balance, and tested under all the test conditions such as load changing, varying environmental conditions, and partial shading conditions.