Buck-boost converter fed SRM drive for solar PV array based water pumping

Abstract

This paper aims at the design of solar photovoltaic (SPV) array fed buck-boost converter based water pumping system utilizing a switched reluctance motor (SRM) drive. The unique approach to control the speed of switched reluctance motor (SRM) drive for water pumping by controlling the DC link voltage of a mid-point converter feeding SRM makes system efficient and reliable. The electronic commutation of the SRM drive at fundamental frequency offers reduced switching losses in mid-point converter and considerably increases the efficiency of proposed system approximately 2–3% over conventional schemes of water pumping systems. Imparting some delay to maximum power point tracking (MPPT) algorithm using selection of proper step size is also introduces intentionally to facilitate the soft starting of SRM drive and control the high starting current of SRM. The buck-boost converter operated in continuous conduction mode (CCM) is not only facilitating the limitless area for incremental conductance (InC)-MPPT algorithm but also provides reduced stress on converter components. The buck-boost converter is the unique DC-DC converter which allowing excellent tracking of PV array maximum power point (MPP) irrespective of temperature and insolation levels. The dynamic and steady state behaviors of the proposed solar PV array fed buck-boost converter employing SRM driven water pumping system are evaluated under the varying insolations using the sim-power system toolboxes of MATLAB/Simulink environment and the prototype has been developed in the laboratory to validate the performance of proposed system.