Systematic procedure for efficient design of electric water pumping systems fed by PV or/and WECS: Application using measured meteorological data for the city of Xanthi/Thrace, Greece

The scope of this paper is to propose a systematic and efficient design procedure for application to either a photovoltaic powered electric water pumping system (PPEWPS) or a wind powered electric water pumping system (WPEWPS). The main aims of this procedure are: (1) to have either the PV type generator or the fixed pitch small size wind turbine (WT) with direct driven permanent magnet synchronous generator (WECS) operate always at its maximum power point (MPP) and (2) to have the separately excited DC motor/pump system (i.e., the load of the system) operate, also and at all times, with its nominal speed nnom. A problem with the PPEWPS and WPEWPS is that, while the proposed control strategy using artificial neural networks (ANN) leads to satisfactory operation with minimal sensors, the armature voltage Uα of the DC motor remains much smaller than its nominal value (especially for very low solar radiations or wind velocities), which may result in non-acceptable motor operation. A practical solution to this problem may be the combined use of the two mentioned systems to form a hybrid electric water pumping system (HEWPS). The PPEWPS, WPEWPS and HEWPS are designed and investigated thoroughly using the proposed systematic procedure and Matlab software for the purpose of an installation under consideration for the city of Xanthi (Thrace Region), Greece.