A single phase double stage grid interfaced photovoltaic system based on improved least mean square algorithm

This paper proposes an improved variable step size kwong least mean square algorithm based single phase double stage solar photovoltaic (SPV) grid interactive system. The interconnection of the distribution system with the SPV system and the load invariability introduces harmonics in the grid current and voltages at the point of interconnection (POI). The double stage topology includes two power stages, the maximum power point tracking (MPPT) power stage where the peak solar power is extricated with subsistence of a boost converter. However, the voltage source converter in the second power stage aids feeding of active power in to the grid and improves the harmonic profile of the system. This control scheme is applied for the adaptive noise cancellation with faster convergence rate and harmonic suppression features. A hardware prototype is developed for the proposed system configuration and is tested under various abnormal conditions to validate system performance. Moreover, the test results conform well to the IEEE standard 519.