Solar PV array fed water pumping system using SEPIC converter based BLDC motor drive

This paper deals with the application of a single ended primary inductor converter (SEPIC) in 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 incremental conductance maximum power point tracking (INC-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 DC-DC 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.