Multimode Features of CIPNLMS-MFX Controlled Single-Phase PV System With Finite State Machine Based Islanding/Synchronization Under Grid Outage

This article presents multimode features of a single-phase photovoltaic (PV) system controlled through a combined improved proportionate-normalized least mean square with modified filtered-X (CIPNLMS-MFX) technique. This system waves off from using the battery storage and successfully operated in standalone mode to achieve the load demand even under the grid outage. The CIPNLMS-MFX based current control technique includes asymmetry parameters and the optimized selection of these parameters provides fast convergence speed, good steady-state response, and improved power quality at nonlinear loads. This PV system is also supported with the synchronization and mode transfer control so that the PV system has autonomous operation under outage and recovery of the grid without disturbing the supply across the domestic loads. A fast detection of a dual cascaded generalized integrator synchronization/islanding structure is presented to evaluate fundamental grid voltage, phase angles, and change in frequency. This structure is robust against the abnormal conditions at the utility grid. The experimental results show that presented CIPNLMS-MFX, DCGI, and finite state machine based logic for islanding/synchronization techniques achieve considerably good performance under various operating scenarios, e.g., outage/ restoration of grid power, varying nonlinear loads, and outage of solar power.