The effect of electrical array reconfiguration on the performance of a PV-powered volumetric water pump

A technique is presented to improve the performance of a photovoltaic (PV) powered permanent magnet DC motor coupled to a screw-type volumetric water pump. The method uses a solid-state electric array reconfiguration controller (EARC), which senses the radiation as low, medium, or high. The controller chooses one favorable set of I -V characteristics for starting and another favorable set of I-V characteristics for steady-state operation. This is done by switching the solar panels, depending upon the starting current requirements and the irradiance level, from a parallel to series-parallel to series connection. This produces a sufficient starting current, especially at low and medium radiation levels, which considerably improves the pump´s performance, particularly in the early morning, in the late evening, and on cloudy days, providing valuable extra pumping hours for the user