Steady-State Performance Characteristics of Photovoltaic System Coupled with a Centrifugal Water Pump

In this article our objective is to obtain steady state characteristics of shunt, series, and separately excited DC motors coupled with a centrifugal water pump supplied through a step-up, step-down, and cuk converter from photovoltaic generator. We assume that there are no storage batteries and, of course, the system must operate on maximum utilization i.e. maximum water must be pumped. It is proven that if maximum utilization is obtained by duty ratio tuning, system utilization maximization and generator peak power tracking will be equal. Thus, a DC/DC converter is used as a peak power tracker. However, a single exception exists in the case of separately excited motors operated in constant converter duty ratio and tuned excitation for maximum utilization. In this case, system utilization maximization and generator peak power tracking will be different. In addition, with the assumption of generator peak power tracking, as in the case of shunt and series motors, system efficiency relative to generator terminals will also be maximized.