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.>