Design and Simulation of Photovoltaic Water Pumping System

A boost-buck (BB) DC-DC converter is proposed for solar photovoltaic (SPV) array fed water pumping system using a permanent magnet brushless DC (BLDC) motor drive. To design a BB converter with suitable voltage control, DC-DC boost and buck converters are cascaded such that it accomplishes the purpose of maximum power point tracking (MPPT) and soft starting of the BLDC motor. The BB converter exhibits the advantages of both the boost and buck converters and interestingly emerges as a solution to problems associated with these converters in SPV applications. The good switch utilization, high efficiency, non-inverting output voltage and low stress on power devices are the features of BB converter. This paper deals with the starting, dynamic and steady state performances under varying atmospheric conditions and examines the effectiveness of the BLDC motor with the proposed BB converter for SPV based water pumping. Simulated results using MATLAB/Simulink followed by the experimental validation have demonstrated the suitability of this drive for SPV based water pumping system