This Work deals with the application of a single-ended primary inductor converter (SEPIC) in a solar photovoltaic (SPV) array fed water pumping system. A permanent magnet brushless DC (BLDC) motor is employed to drive a centrifugal pump coupled to its shaft. Soft starting of the BLDC motor is achieved by controlling the SEPIC through the MPPT algorithm. The SEPIC possesses the merits of non-inverting polarity output voltage, simple gate-drive circuit, and low input current pulsation. Besides these, the SEPIC, operating as a DCDC buck-boost converter can increase or decrease the input voltage level at its output. This property provides the flexibility of optimizing the operating point of the SPV array at any voltage level. The dynamic and steady-state performances of the BLDC motor coupled to a centrifugal water pump fed by the SPV array-SEPIC is evaluated and its suitability is verified through simulated results using MATLAB/ Simulink environment.
 
MATLAB model of Solar PV Array Fed Water Pumping System Using SEPIC Converter Based BLDC Motor Drive