Grid Interfaced Sensorless BLDC Motor Fed Solar Water Pump Using SEPIC Converter

Implementation of grid interfaced system provides uninterrupted operation of water pump even in low solar irradiation condition. BLDC motor in sensorless operation could effectively drive solar water pump due to its good operating performance. The present work deals with the sensorless operation of motor which is achieved through back emf zero crossing identification method derived from the difference of line voltages. The maximum power point tracking of photovoltaic (PV) is done using Single Ended Primary Inductor Converter (SEPIC) through Perturb and Observe (P&O) algorithm. The present study focus on the performance analysis of grid interfaced solar BLDC motor (brushless DC) fed solar water pump using SEPIC converter under four different cases such as operation with PV alone, grid alone, transition from PV to combined mode and transition from grid to PV. The result of the study indicates that motor could operate satisfactorily even in the absence of solar irradiance or at low irradiance of 600 W/m2 with reduced total harmonic distortion.